Archive of Digital Chirp Sub-bottom profile data collected during USGS cruise 09CCT01 offshore of Sabine Pass and Galveston, Texas, March 2009

USGS Publications Warehouse

Forde, Arnell S.; Dadisman, Shawn V.; Flocks, James G.; Dellapenna, Timothy M.; Sanford, Jordan M.; Wiese, Dana S.

2010-01-01

This Digital Versatile Disc (DVD) publication was prepared by an agency of the United States Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.

Utility of Digital Stereo Images for Optic Disc Evaluation

PubMed Central

Ying, Gui-shuang; Pearson, Denise J.; Bansal, Mayank; Puri, Manika; Miller, Eydie; Alexander, Judith; Piltz-Seymour, Jody; Nyberg, William; Maguire, Maureen G.; Eledath, Jayan; Sawhney, Harpreet

2010-01-01

Purpose. To assess the suitability of digital stereo images for optic disc evaluations in glaucoma. Methods. Stereo color optic disc images in both digital and 35-mm slide film formats were acquired contemporaneously from 29 subjects with various cup-to-disc ratios (range, 0.26–0.76; median, 0.475). Using a grading scale designed to assess image quality, the ease of visualizing optic disc features important for glaucoma diagnosis, and the comparative diameters of the optic disc cup, experienced observers separately compared the primary digital stereo images to each subject's 35-mm slides, to scanned images of the same 35-mm slides, and to grayscale conversions of the digital images. Statistical analysis accounted for multiple gradings and comparisons and also assessed image formats under monoscopic viewing. Results. Overall, the quality of primary digital color images was judged superior to that of 35-mm slides (P < 0.001), including improved stereo (P < 0.001), but the primary digital color images were mostly equivalent to the scanned digitized images of the same slides. Color seemingly added little to grayscale optic disc images, except that peripapillary atrophy was best seen in color (P < 0.0001); both the nerve fiber layer (P < 0.0001) and the paths of blood vessels on the optic disc (P < 0.0001) were best seen in grayscale. The preference for digital over film images was maintained under monoscopic viewing conditions. Conclusions. Digital stereo optic disc images are useful for evaluating the optic disc in glaucoma and allow the application of advanced image processing applications. Grayscale images, by providing luminance distinct from color, may be informative for assessing certain features. PMID:20505199

Recent progress of obliquely deposited thin films for industrial applications

NASA Astrophysics Data System (ADS)

Suzuki, Motofumi; Itoh, Tadayoshi; Taga, Yasunori

1999-06-01

More than 10 years ago, birefringent films of metal oxides were formed by oblique vapor deposition and investigated with a view of their application to optical retardation plates. The retardation function of the films was explained in terms of the birefringence caused by the characteristic anisotropic nanostructure inside the films. These films are now classified in the genre of the so-called sculptured thin films. However, the birefringent films thus prepared are not yet industrialized even now due to the crucial lack of the durability and the yield of products. In this review paper, we describe the present status of application process of the retardation films to the information systems such as compact disc and digital versatile disc devices with a special emphasis on the uniformity of retardation properties in a large area and the stability of the optical properties of the obliquely deposited thin films. Finally, further challenges for wide application of the obliquely deposited thin films are also discussed.

Anticipatory guidance preferences of Latina migrant farmworker mothers.

PubMed

Kilanowski, Jill F

2013-01-01

The purpose of the study was to learn preferences of Latina migrant farmworker mothers regarding the presentation of health education materials by discussing the strengths and weaknesses of numerous mixed-media samples. This community-based participatory study was qualitative and descriptive in design. Focus groups were conducted in Spanish in four Midwest migrant camps with a convenience sample of mothers (N = 31). Adult learning and cultural care theories guided the study. Various modes of educational materials on various topics were presented. Mothers preferred comic book-style handouts, games, food replicas, text in English/Spanish, and digital video discs or digital versatile discs, but almost none of them had media-playing equipment. They did not like black-and-white photos or cartoon-like illustrations. Identified themes of importance were colored illustrations, sizes mothers could easily carry in purses, and limited verbiage on a page. The knowledge gained in this study will be used to customize health promotion interventions that are sensitive to migrant farmworker-preferred learning styles. The findings from this study can inform other interventions with Latino populations and serve as a prototype for other populations of immigrant non-English-speaking mothers. Copyright © 2013 National Association of Pediatric Nurse Practitioners. Published by Mosby, Inc. All rights reserved.

Archive of Boomer and Chirp Seismic Reflection Data Collected During USGS Cruise 01RCE02, Southern Louisiana, April and May 2001

USGS Publications Warehouse

Calderon, Karynna; Dadisman, Shawn V.; Flocks, James G.; Wiese, Dana S.

2003-01-01

In April and May of 2001, the U.S. Geological Survey conducted a geophysical study of the Mississippi River Delta, Atchafalaya River Delta, and Shell Island Pass in southern Louisiana. This study was part of a larger USGS River Contaminant Evaluation (RCE) Project. This disc serves as an archive of unprocessed digital seismic reflection data, trackline navigation files, shotpoint navigation maps, observers' logbooks, GIS information, and formal Federal Geographic Data Committee (FGDC) metadata. In addition, a filtered and gained digital GIF-formatted image of each seismic profile is provided. For your convenience, a list of acronyms and abbreviations frequently used in this report has also been provided. This DVD (Digital Versatile Disc) document is readable on any computing platform that has standard DVD driver software installed. Documentation on this DVD was produced using Hyper Text Markup Language (HTML) utilized by the World Wide Web (WWW) and allows the user to access the information by using a web browser (i.e. Netscape or Internet Explorer). To access the information contained on this disc, open the file 'index.htm' located at the top level of the disc using your web browser. This report also contains WWW links to USGS collaborators and other agencies. These links are only accessible if access to the internet is available while viewing the DVD. The archived boomer and chirp seismic reflection data are in standard Society of Exploration Geophysicists (SEG) SEG-Y format (Barry et al., 1975) and may be downloaded for processing with public domain software such as Seismic Unix (SU), currently located at http://www.cwp.mines.edu/cwpcodes. Examples of SU processing scripts are provided in the boom.tar and chirp.tar files located in the SU subfolder of the SOFTWARE folder located at the top level of this DVD. In-house (USGS) DOS and Microsoft Windows compatible software for viewing SEG-Y headers - DUMPSEGY.EXE (Zilhman, 1992) - is provided in the USGS subfolder of the SOFTWARE folder. Processed profile images, shotpoint navigation maps, logbooks, and formal metadata may be viewed with your web browser.

Single-cell isolation using a DVD optical pickup

PubMed Central

Kasukurti, A.; Potcoava, M.; Desai, S.A.; Eggleton, C.; Marr, D. W. M.

2011-01-01

A low-cost single-cell isolation system incorporating a digital versatile disc burner (DVD RW) optical pickup has been developed. We show that these readily available modules have the required laser power and focusing optics to provide a steady Gaussian beam capable of optically trapping micron-sized colloids and red blood cells. Utility of the pickup is demonstrated through the non-destructive isolation of such particles in a laminar-flow based microfluidic device that captures and translates single microscale objects across streamlines into designated channel exits. In this, the integrated objective lens focusing coils are used to steer the optical trap across the channel, resulting in the isolation of colloids and red blood cells using a very inexpensive off-the-shelf optical component. PMID:21643294

Flexible and disposable plasmonic refractive index sensor using nanoimprint lithography

NASA Astrophysics Data System (ADS)

Mohapatra, Saswat; Moirangthem, Rakesh S.

2018-03-01

Nanostructure based plasmonic sensors are highly demanding in various areas due to their label-free and real-time detection capability. In this work, we developed an inexpensive flexible plasmonic sensor using optical disc nanograting via soft UV-nanoimprint lithography (UV-NIL). The polydimethylsiloxane (PDMS) stamp was used to transfer the nanograting structure from digital versatile discs (DVDs) to flexible and transparent polyethylene terephthalate (PET) substrate. Further, the plasmonic sensing substrate was obtained after coating a gold thin film on the top of the imprinted sample. The surface plasmon resonance (SPR) modes excited on gold coated nanograting structure appeared as a dip in the reflectance spectra measured at normal incident of white light in ambient air medium. Electromagnetic simulation based on finite element method (FEM) was used to understand and analyze the excited SPR modes and it is a very close agreement with the experimental results. The bulk refractive index (RI) sensing was performed by the sensor chip using water-glycerol mixture with different concentrations. Experimentally, the bulk RI sensitivity was found to be 797+/-17 nm/RIU.

CD-ROM technology at the EROS data center

USGS Publications Warehouse

Madigan, Michael E.; Weinheimer, Mary C.

1993-01-01

The vast amount of digital spatial data often required by a single user has created a demand for media alternatives to 1/2" magnetic tape. One such medium that has been recently adopted at the U.S. Geological Survey's EROS Data Center is the compact disc (CD). CD's are a versatile, dynamic, and low-cost method for providing a variety of data on a single media device and are compatible with various computer platforms. CD drives are available for personal computers, UNIX workstations, and mainframe systems, either directly connected, or through a network. This medium furnishes a quick method of reproducing and distributing large amounts of data on a single CD. Several data sets are already available on CD's, including collections of historical Landsat multispectral scanner data and biweekly composites of Advanced Very High Resolution Radiometer data for the conterminous United States. The EROS Data Center intends to provide even more data sets on CD's. Plans include specific data sets on a customized disc to fulfill individual requests, and mass production of unique data sets for large-scale distribution. Requests for a single compact disc-read only memory (CD-ROM) containing a large volume of data either for archiving or for one-time distribution can be addressed with a CD-write once (CD-WO) unit. Mass production and large-scale distribution will require CD-ROM replication and mastering.

Longitudinal relations of television, electronic games, and digital versatile discs with changes in diet in adolescents.

PubMed

Falbe, Jennifer; Willett, Walter C; Rosner, Bernard; Gortmaker, Steve L; Sonneville, Kendrin R; Field, Alison E

2014-10-01

Youth spend more time with screens than any activity except sleeping. Screen time is a risk factor for obesity, possibly because of the influence of food and beverage advertising on diet. We sought to assess longitudinal relations of screen time [ie, television, electronic games, digital versatile discs (DVDs)/videos, and total screen time] with the 2-y changes in consumption of foods of low nutritional quality (FLNQ) that are commonly advertised on screens [ie, sugar-sweetened beverages, fast food, sweets, salty snacks, and the sum of these foods (total FLNQ)] and fruit and vegetables. With the use of 2004, 2006, and 2008 waves of the Growing Up Today Study II, which consisted of a cohort of 6002 female and 4917 male adolescents aged 9-16 y in 2004, we assessed screen time (change and baseline) in relation to the 2-y dietary changes. Regression models included 4604 girls and 3668 boys with complete screen time and diet data on ≥2 consecutive questionnaires. Each hour-per-day increase in television, electronic games, and DVDs/videos was associated with increased intake of total FLNQ (range: 0.10-0.28 servings/d; P < 0.05). Each hour-per-day increase in total screen time predicted increased intakes of sugar-sweetened beverages, fast food, sweets, and salty snacks (range: 0.02-0.06 servings/d; P < 0.001) and decreased intakes of fruit and vegetables (range: -0.05 to -0.02 servings/d; P < 0.05). Greater screen time at baseline (except electronic games in boys) was associated with subsequent increased intake of total FLNQ, and greater screen time at baseline (except DVDs/videos) was associated with decreased intake of fruit and vegetables (P < 0.05). Across sex and food groups and in sensitivity analyses, television was most consistently associated with dietary changes. Increases in screen time were associated with increased consumption of foods and beverages of low nutritional quality and decreased consumption of fruit and vegetables. Our results caution against excessive use of screen media, especially television, in youth. © 2014 American Society for Nutrition.

Transition from film to digital fundus photography in the Longitudinal Studies of the Ocular Complications of AIDS (LSOCA)

PubMed Central

Gangaputra, Sapna; Pak, Jeong Won; Peng, Qian; Hubbard, Larry D.; Thayer, Dennis; Krason, Zbigniew; Joyce, Jeff; Danis, Ronald P.

2014-01-01

Purpose To describe the transition to digital imaging and assess any impact on ocular disease classification. Methods Film and digital images, acquired by certified photographers, were evaluated independently according to standard procedures for the following: image quality, presence of cytomegalovirus (CMV) retinitis lesions, their extent, and proximity from disc and macula. Inter-grader agreement within the digital medium was also assessed. Results Among the fifteen eyes with CMV retinitis, the mean difference between film and digital images for linear distance of lesion edge to disc was 0.02 disc diameters (DD), for distance to center of macula was −0.04 DD and area covered by CMV retinitis was 0.95 disc area (DA). There was no statistically significant difference in distance and area measurements between media. Inter grader agreement in measurements of digital images was excellent for distance and area estimated. Conclusion Our results suggest that digital grading of CMV retinitis in LSOCA is comparable to that from film with respect to disease classification, measurements, and reproducibility. These findings provide support for continuity of grading data, despite the necessary transition in imaging media. PMID:21857393

Archive of Boomer Seismic Reflection Data Collected During USGS Cruises 01SCC01 and 01SCC02, Timbalier Bay and Offshore East Timbalier Island, Louisiana, June-August, 2001

USGS Publications Warehouse

Calderon, Karynna; Dadisman, Shawn V.; Flocks, James G.; Kindinger, Jack G.; Wiese, Dana S.

2003-01-01

In June, July, and August of 2001, the U.S. Geological Survey (USGS), in cooperation with the University of New Orleans (UNO), the U.S. Army Corps of Engineers, and the Louisiana Department of Natural Resources, conducted a shallow geophysical and sediment core survey of Timbalier Bay and the Gulf of Mexico offshore East Timbalier Island, Louisiana. This report serves as an archive of unprocessed digital seismic reflection data, trackline navigation files, trackline navigation maps, observers' logbooks, Geographic Information Systems (GIS) information, and formal Federal Geographic Data Committee (FGDC) metadata. In addition, a filtered and gained digital Graphics Interchange Format (GIF) image of each seismic profile is provided. Please see Kulp and others (2002), Flocks and others (2003), and Kulp and others (in prep.) for further information about the sediment cores collected and the geophysical results. For convenience, a list of acronyms and abbreviations frequently used in this report is also included. This Digital Versatile Disc (DVD) document is readable on any computing platform that has standard DVD driver software installed. Documentation on this DVD was produced using Hyper Text Markup Language (HTML) utilized by the World Wide Web (WWW) and allows the user to access the information using a web browser (i.e. Netscape, Internet Explorer). To access the information contained on this disc, open the file 'index.htm' located at the top level of the disc using a web browser. This report also contains WWW links to USGS collaborators and other agencies. These links are only accessible if access to the Internet is available while viewing this DVD. The archived boomer seismic reflection data are in standard Society of Exploration Geophysicists (SEG) SEG-Y format (Barry et al., 1975) and may be downloaded for processing with public domain software such as Seismic Unix (SU), currently located at http://www.cwp.mines.edu/cwpcodes/index.html. Examples of SU processing scripts are provided in the BOOM.tar file located in the SU subfolder of the SOFTWARE folder located at the top level of this disc. In-house (USGS) DOS and Microsoft Windows compatible software for viewing SEG-Y headers - DUMPSEGY.EXE (Zihlman, 1992) - is provided in the USGS subfolder of the SOFTWARE folder. Processed profile images, trackline navigation maps, logbooks, and formal metadata may be viewed with a web browser.

Archive of Chirp Seismic Reflection Data Collected During USGS Cruises 01SCC01 and 01SCC02, Timbalier Bay and Offshore East Timbalier Island, Louisiana, June 30 - July 9 and August 1 - 12, 2001

USGS Publications Warehouse

Calderon, Karynna; Dadisman, Shawn V.; Flocks, James G.; Wiese, Dana S.; Kindinger, Jack G.

2003-01-01

In June, July, and August of 2001, the U.S. Geological Survey (USGS), in cooperation with the University of New Orleans, the U.S. Army Corps of Engineers, and the Louisiana Department of Natural Resources, conducted a shallow geophysical and sediment core survey of Timbalier Bay and the Gulf of Mexico offshore East Timbalier Island, Louisiana. This report serves as an archive of unprocessed digital seismic reflection data, trackline navigation files, trackline navigation maps, observers' logbooks, Geographic Information Systems (GIS) information, and formal Federal Geographic Data Committee (FGDC) metadata. In addition, a gained digital Graphics Interchange Format (GIF) image of each seismic profile is provided. Please see Kulp and others (2002), Flocks and others (2003), and Kulp and others (in prep.) for further information about the sediment cores collected and the geophysical results. For convenience, a list of acronyms and abbreviations frequently used in this report is also included. This Digital Versatile Disc (DVD) document is readable on any computing platform that has standard DVD driver software installed. Documentation on this DVD was produced using Hyper Text Markup Language (HTML) utilized by the World Wide Web (WWW) and allows the user to access the information using a web browser (i.e. Netscape, Internet Explorer). To access the information contained on these discs, open the file 'index.htm' located at the top level of each disc using a web browser. This report also contains WWW links to USGS collaborators and other agencies. These links are only accessible if access to the internet is available while viewing these DVDs. The archived chirp seismic reflection data are in standard Society of Exploration Geophysicists (SEG) SEG-Y format (Barry et al., 1975) and may be downloaded for processing with public domain software such as Seismic Unix (SU), currently located at http://www.cwp.mines.edu/cwpcodes/index.html. Examples of SU processing scripts are provided in the CHIRP.tar file located in the SU subfolder of the SOFTWARE folder located at the top level of each disc. In-house (USGS) DOS and Microsoft Windows compatible software for viewing SEG-Y headers - DUMPSEGY.EXE (Zihlman, 1992) - is provided in the USGS subfolder of the SOFTWARE folder. Processed profile images, trackline navigation maps, logbooks, and formal metadata may be viewed with a web browser.

Army Medical Imaging System - ARMIS

DTIC Science & Technology

1992-08-08

modems , scanners, hard disk drives, dot matrix printers, erasable-optical disc drives, CD-ROM drives, WORM disc drives and tape drives are fully...can use 56K leased lines, TI links, digital data circuits, or public telephone lines. 3. ISDN The Integrated Services Digital Network, ISDN, is a

Drosophila wing imaginal discs respond to mechanical injury via slow InsP3R-mediated intercellular calcium waves

NASA Astrophysics Data System (ADS)

Restrepo, Simon; Basler, Konrad

2016-08-01

Calcium signalling is a highly versatile cellular communication system that modulates basic functions such as cell contractility, essential steps of animal development such as fertilization and higher-order processes such as memory. We probed the function of calcium signalling in Drosophila wing imaginal discs through a combination of ex vivo and in vivo imaging and genetic analysis. Here we discover that wing discs display slow, long-range intercellular calcium waves (ICWs) when mechanically stressed in vivo or cultured ex vivo. These slow imaginal disc intercellular calcium waves (SIDICs) are mediated by the inositol-3-phosphate receptor, the endoplasmic reticulum (ER) calcium pump SERCA and the key gap junction component Inx2. The knockdown of genes required for SIDIC formation and propagation negatively affects wing disc recovery after mechanical injury. Our results reveal a role for ICWs in wing disc homoeostasis and highlight the utility of the wing disc as a model for calcium signalling studies.

Analysis of focusing error signals by differential astigmatic method under off-center tracking in the land-groove-type optical disk

NASA Astrophysics Data System (ADS)

Shinoda, Masahisa; Nakatani, Hidehiko

2015-04-01

We theoretically calculate the behavior of the focusing error signal in the land-groove-type optical disk when the objective lens traverses on out of the radius of the optical disk. The differential astigmatic method is employed instead of the conventional astigmatic method for generating the focusing error signals. The signal behaviors are compared and analyzed in terms of the gain difference of the slope sensitivity of the focusing error signals from the land and the groove. In our calculation, the format of digital versatile disc-random access memory (DVD-RAM) is adopted as the land-groove-type optical disk model, and advantageous conditions for suppressing the gain difference are investigated. The calculation method and results described in this paper will be reflected in the next generation land-groove-type optical disks.

Television animation store: Recording pictures on a parallel transfer magnetic disc

NASA Astrophysics Data System (ADS)

Durey, A. J.

1984-12-01

The recording and replaying of digital video signals using a computer-type magnetic disc-drive as part of an electronic rostrum camera animation system is described. The system was developed to enable picture sequences to be generated directly as television signals, instead of using cine film. The characteristics of the disc-drive are described together with data processing, error protection and signal synchronization systems, which enable digital television YUV component signals, sampled at 12 MHz, 4 MHz and 4 MHz respectively, to be recorded and replayed in real time.

Quantitating Human Optic Disc Topography

NASA Astrophysics Data System (ADS)

Graebel, William P.; Cohan, Bruce E.; Pearch, Andrew C.

1980-07-01

A method is presented for quantitatively expressing the topography of the human optic disc, applicable in a clinical setting to the diagnosis and management of glaucoma. Pho-tographs of the disc illuminated by a pattern of fine, high contrast parallel lines are digitized. From the measured deviation of the lines as they traverse the disc surface, disc topography is calculated, using the principles of optical sectioning. The quantitators applied to express this topography have the the following advantages : sensitivity to disc shape; objectivity; going beyond the limits of cup-disc ratio estimates and volume calculations; perfect generality in a mathematical sense; an inherent scheme for determining a non-subjective reference frame to compare different discs or the same disc over time.

Study report on laser storage and retrieval of image data

NASA Technical Reports Server (NTRS)

Becker, C. H.

1976-01-01

The theoretical foundation is presented for a system of real-time nonphotographic and nonmagnetic digital laser storage and retrieval of image data. The system utilizes diffraction-limited laser focusing upon thin metal films, melting elementary holes in the metal films in laser focus. The metal films are encapsulated in rotating flexible mylar discs which act as the permanent storage carries. Equal sized holes encompass two dimensional digital ensembles of information bits which are time-sequentially (bit by bit) stored and retrieved. The bits possess the smallest possible size, defined by the Rayleigh criterion of coherent physical optics. Space and time invariant reflective read-out of laser discs with a small laser, provides access to the stored digital information. By eliminating photographic and magnetic data processing, which characterize the previous state of the art, photographic grain, diffusion, and gamma-distortion do not exist. Similarly, magnetic domain structures, magnetic gaps, and magnetic read-out are absent with a digital laser disc system.

Analysis of behavior of focusing error signals generated by astigmatic method when a focused spot moves beyond the radius of a land-groove-type optical disk

NASA Astrophysics Data System (ADS)

Shinoda, Masahisa; Nakatani, Hidehiko; Nakai, Kenya; Ohmaki, Masayuki

2015-09-01

We theoretically calculate behaviors of focusing error signals generated by an astigmatic method in a land-groove-type optical disk. The focusing error signal from the land does not coincide with that from the groove. This behavior is enhanced when a focused spot of an optical pickup moves beyond the radius of the optical disk. A gain difference between the slope sensitivities of focusing error signals from the land and the groove is an important factor with respect to stable focusing servo control. In our calculation, the format of digital versatile disc-random access memory (DVD-RAM) is adopted as the land-groove-type optical disk model, and the dependences of the gain difference on various factors are investigated. The gain difference strongly depends on the optical intensity distribution of the laser beam in the optical pickup. The calculation method and results in this paper will be reflected in newly developed land-groove-type optical disks.

Composition and substrate-dependent strength of the silken attachment discs in spiders

PubMed Central

Grawe, Ingo; Wolff, Jonas O.; Gorb, Stanislav N.

2014-01-01

Araneomorph spiders have evolved different silks with dissimilar material properties, serving different purposes. The two-compound pyriform secretion is used to glue silk threads to substrates or to other threads. It is applied in distinct patterns, called attachment discs. Although ubiquitously found in spider silk applications and hypothesized to be strong and versatile at low material consumption, the performance of attachment discs on different substrates remains unknown. Here, we analyse the detachment forces and fracture mechanics of the attachment discs spun by five different species on three different substrates, by pulling on the upstream part of the attached thread. Results show that although the adhesion of the pyriform glue is heavily affected by the substrate, even on Teflon it is frequently strong enough to hold the spider's weight. As plant surfaces are often difficult to wet, they are hypothesized to be the major driving force for evolution of the pyriform secretion. PMID:25030386

Precision of lumbar intervertebral measurements: does a computer-assisted technique improve reliability?

PubMed

Pearson, Adam M; Spratt, Kevin F; Genuario, James; McGough, William; Kosman, Katherine; Lurie, Jon; Sengupta, Dilip K

2011-04-01

Comparison of intra- and interobserver reliability of digitized manual and computer-assisted intervertebral motion measurements and classification of "instability." To determine if computer-assisted measurement of lumbar intervertebral motion on flexion-extension radiographs improves reliability compared with digitized manual measurements. Many studies have questioned the reliability of manual intervertebral measurements, although few have compared the reliability of computer-assisted and manual measurements on lumbar flexion-extension radiographs. Intervertebral rotation, anterior-posterior (AP) translation, and change in anterior and posterior disc height were measured with a digitized manual technique by three physicians and by three other observers using computer-assisted quantitative motion analysis (QMA) software. Each observer measured 30 sets of digital flexion-extension radiographs (L1-S1) twice. Shrout-Fleiss intraclass correlation coefficients for intra- and interobserver reliabilities were computed. The stability of each level was also classified (instability defined as >4 mm AP translation or 10° rotation), and the intra- and interobserver reliabilities of the two methods were compared using adjusted percent agreement (APA). Intraobserver reliability intraclass correlation coefficients were substantially higher for the QMA technique THAN the digitized manual technique across all measurements: rotation 0.997 versus 0.870, AP translation 0.959 versus 0.557, change in anterior disc height 0.962 versus 0.770, and change in posterior disc height 0.951 versus 0.283. The same pattern was observed for interobserver reliability (rotation 0.962 vs. 0.693, AP translation 0.862 vs. 0.151, change in anterior disc height 0.862 vs. 0.373, and change in posterior disc height 0.730 vs. 0.300). The QMA technique was also more reliable for the classification of "instability." Intraobserver APAs ranged from 87 to 97% for QMA versus 60% to 73% for digitized manual measurements, while interobserver APAs ranged from 91% to 96% for QMA versus 57% to 63% for digitized manual measurements. The use of QMA software substantially improved the reliability of lumbar intervertebral measurements and the classification of instability based on flexion-extension radiographs.

Digital plus analog output encoder

NASA Technical Reports Server (NTRS)

Hafle, R. S. (Inventor)

1976-01-01

The disclosed encoder is adapted to produce both digital and analog output signals corresponding to the angular position of a rotary shaft, or the position of any other movable member. The digital signals comprise a series of binary signals constituting a multidigit code word which defines the angular position of the shaft with a degree of resolution which depends upon the number of digits in the code word. The basic binary signals are produced by photocells actuated by a series of binary tracks on a code disc or member. The analog signals are in the form of a series of ramp signals which are related in length to the least significant bit of the digital code word. The analog signals are derived from sine and cosine tracks on the code disc.

Publications - DDS 12 | Alaska Division of Geological & Geophysical Surveys

Science.gov Websites

; Geophysical Surveys Digital Data Series 12, 1 DVD. http://doi.org/10.14509/29555 Publication Products Disc DVD catalog (34.0 M) Digital Geospatial Data Digital Geospatial Data Black Mtn., Liscum, Goodpaster, Salch R

Novel localized heating technique on centrifugal microfluidic disc with wireless temperature monitoring system.

PubMed

Joseph, Karunan; Ibrahim, Fatimah; Cho, Jongman

2015-01-01

Recent advances in the field of centrifugal microfluidic disc suggest the need for electrical interface in the disc to perform active biomedical assays. In this paper, we have demonstrated an active application powered by the energy harvested from the rotation of the centrifugal microfluidic disc. A novel integration of power harvester disc onto centrifugal microfluidic disc to perform localized heating technique is the main idea of our paper. The power harvester disc utilizing electromagnetic induction mechanism generates electrical energy from the rotation of the disc. This contributes to the heat generation by the embedded heater on the localized heating disc. The main characteristic observed in our experiment is the heating pattern in relative to the rotation of the disc. The heating pattern is monitored wirelessly with a digital temperature sensing system also embedded on the disc. Maximum temperature achieved is 82 °C at rotational speed of 2000 RPM. The technique proves to be effective for continuous heating without the need to stop the centrifugal motion of the disc.

16 CFR 4.2 - Requirements as to form, and filing of documents other than correspondence.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Administrative Law Judge) or twelve (12) paper copies (if before the Commission), and an electronic copy in Adobe... an electronic copy on a compact disc (CD) or digital video disc (DVD) in Adobe portable document...

16 CFR 4.2 - Requirements as to form, and filing of documents other than correspondence.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Administrative Law Judge) or twelve (12) paper copies (if before the Commission), and an electronic copy in Adobe... an electronic copy on a compact disc (CD) or digital video disc (DVD) in Adobe portable document...

Application of Digital Object Identifiers to data sets at the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC)

NASA Astrophysics Data System (ADS)

Vollmer, B.; Ostrenga, D.; Johnson, J. E.; Savtchenko, A. K.; Shen, S.; Teng, W. L.; Wei, J. C.

2013-12-01

Digital Object Identifiers (DOIs) are applied to selected data sets at the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC). The DOI system provides an Internet resolution service for unique and persistent identifiers of digital objects. Products assigned DOIs include data from the NASA MEaSUREs Program, the Earth Observing System (EOS) Aqua Atmospheric Infrared Sounder (AIRS) and EOS Aura High Resolution Dynamics Limb Sounder (HIRDLS). DOIs are acquired and registered through EZID, California Digital Library and DataCite. GES DISC hosts a data set landing page associated with each DOI containing information on and access to the data including a recommended data citation when using the product in research or applications. This work includes participation with the earth science community (e.g., Earth Science Information Partners (ESIP) Federation) and the NASA Earth Science Data and Information System (ESDIS) Project to identify, establish and implement best practices for assigning DOIs and managing supporting information, including metadata, for earth science data sets. Future work includes (1) coordination with NASA mission Science Teams and other data providers on the assignment of DOIs for other GES DISC data holdings, particularly for future missions such as Orbiting Carbon Observatory -2 and -3 (OCO-2, OCO-3) and projects (MEaSUREs 2012), (2) construction of landing pages that are both human and machine readable, and (3) pursuing the linking of data and publications with tools such as the Thomson Reuters Data Citation Index.

Total analysis systems with Thermochromic Etching Discs technology.

PubMed

Avella-Oliver, Miquel; Morais, Sergi; Carrascosa, Javier; Puchades, Rosa; Maquieira, Ángel

2014-12-16

A new analytical system based on Thermochromic Etching Discs (TED) technology is presented. TED comprises a number of attractive features such as track independency, selective irradiation, a high power laser, and the capability to create useful assay platforms. The analytical versatility of this tool opens up a wide range of possibilities to design new compact disc-based total analysis systems applicable in chemistry and life sciences. In this paper, TED analytical implementation is described and discussed, and their analytical potential is supported by several applications. Microarray immunoassay, immunofiltration assay, solution measurement, and cell culture approaches are herein addressed in order to demonstrate the practical capacity of this system. The analytical usefulness of TED technology is herein demonstrated, describing how to exploit this tool for developing truly integrated analytical systems that provide solutions within the point of care framework.

Which Disc Player for Education? A Comparative Evaluation.

ERIC Educational Resources Information Center

Leveridge, Leo L.; Lyons, David S.

1983-01-01

Advantages and disadvantages of videodisc players using digital program dumps are discussed. Indicates that, although digital dumps on videodiscs can be used to deliver interactive audiovisual programs about as effectively as external computer programs, disadvantages greatly outweigh advantages. Thus, digital program dumps recorded on videodiscs…

Optical Disc Applications in Libraries.

ERIC Educational Resources Information Center

Andre, Pamela Q. J.

1989-01-01

Discusses a variety of library applications of optical disc storage technology, including CD-ROM, digital videodisc, and WORM. Research and development projects at the Library of Congress, National Library of Medicine, and National Agricultural Library are described, products offered by library networks are reviewed, and activities in academic and…

A lab-in-a-droplet bioassay strategy for centrifugal microfluidics with density difference pumping, power to disc and bidirectional flow control.

PubMed

Wang, Guanghui; Ho, Ho-Pui; Chen, Qiulan; Yang, Alice Kar-Lai; Kwok, Ho-Chin; Wu, Shu-Yuen; Kong, Siu-Kai; Kwan, Yiu-Wa; Zhang, Xuping

2013-09-21

In this paper, we present a lab-in-a-droplet bioassay strategy for a centrifugal microfluidics or lab-on-a-disc (LOAD) platform with three important advancements including density difference pumping, power to disc and bidirectional flow control. First, with the water based bioassay droplets trapped in a micro-channel filled with mineral oil, centrifugal force due to the density difference between the water and oil phases actuates droplet movement while the oil based medium remains stationary. Second, electricity is coupled to the rotating disc through a split-core transformer, thus enabling on-chip real-time heating in selected areas as desired and wireless programmable functionality. Third, an inertial mechanical structure is proposed to achieve bidirectional flow control within the spinning disc. The droplets can move back and forth between two heaters upon changing the rotational speed. Our platform is an essential and versatile solution for bioassays such as those involving DNA amplification, where localized temperature cycling is required. Finally, without the loss of generality, we demonstrate the functionality of our platform by performing real-time polymerase chain reaction (RT-PCR) in a linear microchannel made with PTFE (Teflon) micro-tubing.

Digital video technology, today and tomorrow

NASA Astrophysics Data System (ADS)

Liberman, J.

1994-10-01

Digital video is probably computing's fastest moving technology today. Just three years ago, the zenith of digital video technology on the PC was the successful marriage of digital text and graphics with analog audio and video by means of expensive analog laser disc players and video overlay boards. The state of the art involves two different approaches to fully digital video on computers: hardware-assisted and software-only solutions.

40 CFR 3.1 - Who does this part apply to?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Regulations (CFR); and (2) States, tribes, and local governments administering or seeking to administer..., compact disc, digital video disc, or tape in satisfaction of reporting requirements, as permitted under... does not apply to any data transfers between EPA and states, tribes, or local governments as a part of...

Recent Developments in Interactive and Communicative CALL: Hypermedia and "Intelligent" Systems.

ERIC Educational Resources Information Center

Coughlin, Josette M.

Two recent developments in computer-assisted language learning (CALL), interactive video systems and "intelligent" games, are discussed. Under the first heading, systems combining the use of a computer and video disc player are described, and Compact Discs Interactive (CDI) and Digital Video Interactive (DVI) are reviewed. The…

Medical Information on Optical Disc*

PubMed Central

Schipma, Peter B.; Cichocki, Edward M.; Ziemer, Susan M.

1987-01-01

Optical discs may permit a revolutionary change in the distribution and use of medical information. A single compact disc, similar in size to that used for digital audio recording, can contain over 500 million characters of information that is accessible by a Personal Computer. These discs can be manufactured at a cost lower than that of print on paper, at reasonable volumes. Software can provide the health care professional with nearly instantaneous access to the information. Thus, for the first time, the opportunity exists to have large local medical information collections. This paper describes an application of this technology in the field of Oncology.

Formation, function, and exhaustion of notochordal cytoplasmic vacuoles within intervertebral disc: current understanding and speculation.

PubMed

Wang, Feng; Gao, Zeng-Xin; Cai, Feng; Sinkemani, Arjun; Xie, Zhi-Yang; Shi, Rui; Wei, Ji-Nan; Wu, Xiao-Tao

2017-08-22

Notochord nucleus pulposus cells are characteristic of containing abundant and giant cytoplasmic vacuoles. This review explores the embryonic formation, biological function, and postnatal exhaustion of notochord vacuoles, aiming to characterize the signal network transforming the vacuolated nucleus pulposus cells into the vacuole-less chondrocytic cells. Embryonically, the cytoplasmic vacuoles within vertebrate notochord originate from an evolutionarily conserved vacuolation process during neurulation, which may continue to provide mechanical and signal support in constructing a mammalian intervertebral disc. For full vacuolation, a vacuolating specification from dorsal organizer cells, synchronized convergent extension, well-structured notochord sheath, and sufficient post-Golgi trafficking in notochord cells are required. Postnatally, age-related and species-specific exhaustion of vacuolated nucleus pulposus cells could be potentiated by Fas- and Fas ligand-induced apoptosis, intolerance to mechanical stress and nutrient deficiency, vacuole-mediated proliferation check, and gradual de-vacuolation within the avascular and compression-loaded intervertebral disc. These results suggest that the notochord vacuoles are active and versatile organelles for both embryonic notochord and postnatal nucleus pulposus, and may provide novel information on intervertebral disc degeneration to guide cell-based regeneration.

Formation, function, and exhaustion of notochordal cytoplasmic vacuoles within intervertebral disc: current understanding and speculation

PubMed Central

Sinkemani, Arjun; Xie, Zhi-Yang; Shi, Rui; Wei, Ji-Nan; Wu, Xiao-Tao

2017-01-01

Notochord nucleus pulposus cells are characteristic of containing abundant and giant cytoplasmic vacuoles. This review explores the embryonic formation, biological function, and postnatal exhaustion of notochord vacuoles, aiming to characterize the signal network transforming the vacuolated nucleus pulposus cells into the vacuole-less chondrocytic cells. Embryonically, the cytoplasmic vacuoles within vertebrate notochord originate from an evolutionarily conserved vacuolation process during neurulation, which may continue to provide mechanical and signal support in constructing a mammalian intervertebral disc. For full vacuolation, a vacuolating specification from dorsal organizer cells, synchronized convergent extension, well-structured notochord sheath, and sufficient post-Golgi trafficking in notochord cells are required. Postnatally, age-related and species-specific exhaustion of vacuolated nucleus pulposus cells could be potentiated by Fas- and Fas ligand-induced apoptosis, intolerance to mechanical stress and nutrient deficiency, vacuole-mediated proliferation check, and gradual de-vacuolation within the avascular and compression-loaded intervertebral disc. These results suggest that the notochord vacuoles are active and versatile organelles for both embryonic notochord and postnatal nucleus pulposus, and may provide novel information on intervertebral disc degeneration to guide cell-based regeneration. PMID:28915712

Development of STOLAND, a versatile navigation, guidance and control system

NASA Technical Reports Server (NTRS)

Young, L. S.; Hansen, Q. M.; Rouse, W. E.; Osder, S. S.

1972-01-01

STOLAND has been developed to perform navigation, guidance, control, and flight management experiments in advanced V/STOL aircraft. The experiments have broad requirements and have dictated that STOLAND be capable of providing performance that would be realistic and equivalent to a wide range of current and future avionics systems. An integrated digital concept using modern avionics components was selected as the simplest approach to maximizing versatility and growth potential. Unique flexibility has been obtained by use of a single, general-purpose digital computer for all navigation, guidance, control, and displays computation.

The USGS Side-Looking Airborne Radar (SLAR) program: CD-ROMs expand potential for petroleum exploration

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

Kover, A.N.; Schoonmaker, J.W. Jr.; Pohn. H.A.

1991-03-01

The United States Geological Survey (USGS) began the systematic collection of Side-Looking Airborne Radar (SLAR) data in 1980. The SLAR image data, useful for many geologic applications including petroleum exploration, are compiled into mosaics using the USGS 1:250,000-scale topographic map series for format and control. Mosaics have been prepared for over 35% of the United States. Image data collected since 1985 are also available as computer compatible tapes (CCTs) for digital analysis. However, the use of tapes is often cumbersome. To make digital data more readily available for use on a microcomputer, the USGS has started to prepare compact discs-readmore » only memory (CD-ROM). Several experimental discs have been compiled to demonstrate the utility of the medium to make available very large data sets. These discs include necessary nonproprietary software text, radar, and other image data. The SLAR images selected for these discs show significantly different geologic features and include the Long Valley caldera, a section of the San Andreas fault in the Monterey area, the Grand Canyon, and glaciers in southeastern Alaska. At present, several CD-ROMs are available as standard products distributed by the USGS EROS Data Center in Sioux Falls, South Dakota 57198. This is also the source for all USGS SLAR photographic and digital material.« less

Digital Image Speckle Correlation for the Quantification of the Cosmetic Treatment with Botulinum Toxin Type A (BTX-A)

NASA Astrophysics Data System (ADS)

Bhatnagar, Divya; Conkling, Nicole; Rafailovich, Miriam; Dagum, Alexander

2012-02-01

The skin on the face is directly attached to the underlying muscles. Here, we successfully introduce a non-invasive, non-contact technique, Digital Image Speckle Correlation (DISC), to measure the precise magnitude and duration of facial muscle paralysis inflicted by BTX-A. Subjective evaluation by clinicians and patients fail to objectively quantify the direct effect and duration of BTX-A on the facial musculature. By using DISC, we can (a) Directly measure deformation field of the facial skin and determine the locus of facial muscular tension(b)Quantify and monitor muscular paralysis and subsequent re-innervation following injection; (c) Continuously correlate the appearance of wrinkles and muscular tension. Two sequential photographs of slight facial motion (frowning, raising eyebrows) are taken. DISC processes the images to produce a vector map of muscular displacement from which spatially resolved information is obtained regarding facial tension. DISC can track the ability of different muscle groups to contract and can be used to predict the site of injection, quantify muscle paralysis and the rate of recovery following BOTOX injection.

Compressed 3D and 2D digital images versus standard 3D slide film for the evaluation of glaucomatous optic nerve features.

PubMed

Sandhu, Simrenjeet; Rudnisky, Chris; Arora, Sourabh; Kassam, Faazil; Douglas, Gordon; Edwards, Marianne C; Verstraten, Karin; Wong, Beatrice; Damji, Karim F

2018-03-01

Clinicians can feel confident compressed three-dimensional digital (3DD) and two-dimensional digital (2DD) imaging evaluating important features of glaucomatous disc damage is comparable to the previous gold standard of stereoscopic slide film photography, supporting the use of digital imaging for teleglaucoma applications. To compare the sensitivity and specificity of 3DD and 2DD photography with stereo slide film in detecting glaucomatous optic nerve head features. This prospective, multireader validation study imaged and compressed glaucomatous, suspicious or normal optic nerves using a ratio of 16:1 into 3DD and 2DD (1024×1280 pixels) and compared both to stereo slide film. The primary outcome was vertical cup-to-disc ratio (VCDR) and secondary outcomes, including disc haemorrhage and notching, were also evaluated. Each format was graded randomly by four glaucoma specialists. A protocol was implemented for harmonising data including consensus-based interpretation as needed. There were 192 eyes imaged with each format. The mean VCDR for slide, 3DD and 2DD was 0.59±0.20, 0.60±0.18 and 0.62±0.17, respectively. The agreement of VCDR for 3DD versus film was κ=0.781 and for 2DD versus film was κ=0.69. Sensitivity (95.2%), specificity (95.2%) and area under the curve (AUC; 0.953) of 3DD imaging to detect notching were better (p=0.03) than for 2DD (90.5%; 88.6%; AUC=0.895). Similarly, sensitivity (77.8%), specificity (98.9%) and AUC (0.883) of 3DD to detect disc haemorrhage were better (p=0.049) than for 2DD (44.4%; 99.5%; AUC=0.72). There was no difference between 3DD and 2DD imaging in detecting disc tilt (p=0.7), peripapillary atrophy (p=0.16), grey crescent (p=0.1) or pallor (p=0.43), although 3D detected sloping better (p=0.013). Both 3DD and 2DD imaging demonstrates excellent reproducibility in comparison to stereo slide film with experts evaluating VCDR, notching and disc haemorrhage. 3DD in this study was slightly more accurate than 2DD for evaluating disc haemorrhage, notching and sloping. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The secular evolution of discrete quasi-Keplerian systems. II. Application to a multi-mass axisymmetric disc around a supermassive black hole

NASA Astrophysics Data System (ADS)

Fouvry, J.-B.; Pichon, C.; Chavanis, P.-H.

2018-01-01

A discrete self-gravitating quasi-Keplerian razor-thin axisymmetric stellar disc orbiting a massive black hole sees its orbital structure diffuse on secular timescales as a result of a self-induced resonant relaxation. In the absence of collective effects, such a process is described by the recently derived inhomogeneous multi-mass degenerate Landau equation. Relying on Gauss' method, we computed the associated drift and diffusion coefficients to characterise the properties of the resonant relaxation of razor-thin discs. For a disc-like configuration in our Galactic centre, we showed how this secular diffusion induces an adiabatic distortion of orbits and estimate the typical timescale of resonant relaxation. When considering a disc composed of multiple masses similarly distributed, we have illustrated how the population of lighter stars will gain eccentricity, driving it closer to the central black hole, provided the distribution function increases with angular momentum. The kinetic equation recovers as well the quenching of the resonant diffusion of a test star in the vicinity of the black hole (the "Schwarzschild barrier") as a result of the divergence of the relativistic precessions. The dual stochastic Langevin formulation yields consistent results and offers a versatile framework in which to incorporate other stochastic processes.

Transformations: Technology and the Music Industry.

ERIC Educational Resources Information Center

Peters, G. David

2001-01-01

Focuses on the companies and organizations of the Music Industry Conference (MIC). Addresses topics such as: changes in companies due to technology, audio compact discs, the music instrument digital interface (MIDI) , digital sound recording, and the MIC on-line music instruction programs offered. (CMK)

Color-size Relations of Disc Galaxies with Similar Stellar Masses

NASA Astrophysics Data System (ADS)

Fu, W.; Chang, R. X.; Shen, S. Y.; Zhang, B.

2011-01-01

To investigate the correlations between colors and sizes of disc galaxies with similar stellar masses, a sample of 7959 local face-on disc galaxies is collected from the main galaxy sample of the Seventh Data Release of Sloan Digital Sky Survey (SDSS DR7). Our results show that, under the condition that the stellar masses of disc galaxies are similar, the relation between u-r and size is weak, while g-r, r-i and r-z colors decrease with disk size. This means that the color-size relations of disc galaxies with similar stellar masses do exist, i.e., the more extended disc galaxies with similar stellar masses tend to have bluer colors. An artificial sample is constructed to confirm that this correlation is not driven by the color-stellar mass relations and size-stellar mass relation of disc galaxies. Our results suggest that the mass distribution of disk galaxies may have an important influence on their stellar formation history, i.e., the galaxies with more extended mass distribution evolve more slowly.

SCANIT: centralized digitizing of forest resource maps or photographs

Treesearch

Elliot L. Amidon; E. Joyce Dye

1981-01-01

Spatial data on wildland resource maps and aerial photographs can be analyzed by computer after digitizing. SCANIT is a computerized system for encoding such data in digital form. The system, consisting of a collection of computer programs and subroutines, provides a powerful and versatile tool for a variety of resource analyses. SCANIT also may be converted easily to...

Watershed boundaries and digital elevation model of Oklahoma derived from 1:100,000-scale digital topographic maps

USGS Publications Warehouse

Cederstrand, J.R.; Rea, A.H.

1995-01-01

This document provides a general description of the procedures used to develop the data sets included on this compact disc. This compact disc contains watershed boundaries for Oklahoma, a digital elevation model, and other data sets derived from the digital elevation model. The digital elevation model was produced using the ANUDEM software package, written by Michael Hutchinson and licensed from the Centre for Resource and Environmental Studies at The Australian National University. Elevation data (hypsography) and streams (hydrography) from digital versions of the U.S. Geological Survey 1:100,000-scale topographic maps were used by the ANUDEM package to produce a hydrologically conditioned digital elevation model with a 60-meter cell size. This digital elevation model is well suited for drainage-basin delineation using automated techniques. Additional data sets include flow-direction, flow-accumulation, and shaded-relief grids, all derived from the digital elevation model, and the hydrography data set used in producing the digital elevation model. The watershed boundaries derived from the digital elevation model have been edited to be consistent with contours and streams from the U.S. Geological Survey 1:100,000-scale topographic maps. The watershed data set includes boundaries for 11-digit Hydrologic Unit Codes (watersheds) within Oklahoma, and 8-digit Hydrologic Unit Codes (cataloging units) outside Oklahoma. Cataloging-unit boundaries based on 1:250,000-scale maps outside Oklahoma for the Arkansas, Red, and White River basins are included. The other data sets cover Oklahoma, and where available, portions of 1:100,000-scale quadrangles adjoining Oklahoma.

Thermal expansion coefficient determination of polylactic acid using digital image correlation

NASA Astrophysics Data System (ADS)

Botean, Adrian-Ioan

2018-02-01

This paper aims determining the linear thermal expansion coefficient (CTE) of polylactic acid (PLA) using an optical method for measuring deformations called digital image correlation method (DIC). Because PLA is often used in making many pieces with 3D printing technology, it is opportune to know this coefficient to obtain a higher degree of precision in the construction of parts and to monitor deformations when these parts are subjected to a thermal gradient. Are used two PLA discs with 20 and 40% degree of filling. In parallel with this approach was determined the linear thermal expansion coefficient (CTE) for the copper cylinder on the surface of which are placed the two discs of PLA.

76 FR 12994 - In the Matter of Certain Digital Televisions and Components Thereof, and Certain Electronic...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-09

... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-764] In the Matter of Certain Digital Televisions and Components Thereof, and Certain Electronic Devices Having a Blu-Ray Disc Player and Components Thereof; Notice of Investigation AGENCY: U.S. International Trade Commission. ACTION: Institution of...

DIGITAL GEOLOGIC MAP OF SHERMAN QUADRANGLE, NORTH CENTRAL TEXAS (CD-ROM)

EPA Science Inventory

This compact disc contains digital data sets of the surficial geology and geologic faults for the 1:250,000-scale Sherman quadrangle, North Central Texas, and can be used to make geologic maps, and determine approximate areas and locations of various geologic units. The source d...

Evaluation of the color stability of two techniques for reproducing artificial irides after microwave polymerization

PubMed Central

GOIATO, Marcelo Coelho; dos SANTOS, Daniela Micheline; MORENO, Amália; GENNARI-FILHO, Humberto; PELLIZZER, Eduardo Piza

2011-01-01

The use of ocular prostheses for ophthalmic patients aims to rebuild facial aesthetics and provide an artificial substitute to the visual organ. Natural intemperate conditions promote discoloration of artificial irides and many studies have attempted to produce irides with greater chromatic paint durability using different paint materials. Objectives The present study evaluated the color stability of artificial irides obtained with two techniques (oil painting and digital image) and submitted to microwave polymerization. Material and Methods Forty samples were fabricated simulating ocular prostheses. Each sample was constituted by one disc of acrylic resin N1 and one disc of colorless acrylic resin with the iris interposed between the discs. The irides in brown and blue color were obtained by oil painting or digital image. The color stability was determined by a reflection spectrophotometer and measurements were taken before and after microwave polymerization. Statistical analysis of the techniques for reproducing artificial irides was performed by applying the normal data distribution test followed by 2-way ANOVA and Tukey HSD test (α=.05). Results Chromatic alterations occurred in all specimens and statistically significant differences were observed between the oil-painted samples and those obtained by digital imaging. There was no statistical difference between the brown and blue colors. Independently of technique, all samples suffered color alterations after microwave polymerization. Conclusion The digital imaging technique for reproducing irides presented better color stability after microwave polymerization. PMID:21625733

Meeting the Challenges of Regional Security

DTIC Science & Technology

1994-02-01

targets over time, assessing strike damage, and, of course, developing up-to- date maps of crucial urban and industrial areas. Coupled with modem digital ...of huge diverse data bases is key to dissecting criminal infrastructures, and identifying relevant regional and global linkages. New digital processing...cities). They can aid in reaction force planning and training. One 10-inch optical disc can easily store 25 (and display at any scale with 4- digit

Northeast Artificial Intelligence Consortium (NAIC) Review of Technical Tasks. Volume 2, Part 1.

DTIC Science & Technology

1987-07-01

34- . 6.2 Transformation Invariant Attributes for S Digitized Object Outlines ................................. 469 6.3 Design of an Inference Engine for an...Attributes for Digital Object Outlines ...................................... 597 7 SPEECH UNDERSTANDING RESEARCH ( Rochester Institute of Technology...versatile maintenance expert system ES) for trouble-shooting--’ digital circuits. +" Some diagnosis systems, such as MYCLN [19] for medical diagnosis and CRIB

75 FR 5614 - Privacy Act of 1974; Department of Homeland Security/ALL-025 Law Enforcement Authority in Support...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-03

...'s or entity's name; Digital photograph; Date of birth, place of birth, and age; Social security number; Duty/work address and telephone number; Alias; Race and ethnicity; Citizenship; Fingerprints; Sex... servers, magnetic disc, tape, digital media, and CD-ROM. RETRIEVABILITY: Records may be retrieved by...

Digital Talking Books: Planning for the Future.

ERIC Educational Resources Information Center

Cookson, John; Cylke, Frank Kurt; Dixon, Judith; Fistick, Robert E.; Fitzpatrick, Vicki; Kormann, Wells B.; Moodie, Michael M.; Redmond, Linda; Thuronyi, George

This report describes the plans of the National Library Service for the Blind and Physically Handicapped (NLS) to convert their talking books service to a digitally based audio system. The NLS program selects and produces full-length books and magazines in braille and on recorded disc and cassettes and distributes them to a cooperating network of…

A Survey of Recent Advances in Optical and Multimedia Information Technologies.

ERIC Educational Resources Information Center

Jessop, Deborah

1997-01-01

Examines developments in multimedia technologies and in the World Wide Web. Discusses CD-recordable, CD-rewritable, cable modems, personal digital assistants, digital video discs, interactivity and virtual worlds, advertising on the Web, and Intranets and CD-ROM networks. Eight tables and figures show costs, download time, estimated sales, storage…

An in vivo analysis of facial muscle change treated with botulinum toxin type A using digital image speckle correlation

NASA Astrophysics Data System (ADS)

Xu, Yan; Palmaccio, Samantha Palmaccio; Bui, Duc; Dagum, Alexander; Rafailovich, Miriam

Been famous for clinical use from early 1980s, the neuromuscular blocking agent Botulinum toxin type A (BTX-A), has been used to reduce wrinkles for a long time. Only little research has been done to quantify the change of muscle contraction before and after injection and most research paper depend on subjective evaluation from both patients and surgeons. In our research, Digital Image Speckle Correlation (DISC) was employed to study the mechanical properties of skin, contraction mode of muscles (injected) and reaction of neighbor muscle group (un-injected).At the same time, displacement patterns (vector maps)generated by DISC can predict injection locus for surgeons who normally handle it depending only on visual observation.

Performance of the Versatile Array of Neutron Detectors at Low Energy (VANDLE)

DOE PAGES

Peters, W. A.; Ilyushkin, S.; Madurga, M.; ...

2016-08-26

The Versatile Array of Neutron Detectors at Low Energy (VANDLE) is a new, highly efficient plastic-scintillator array constructed for decay and transfer reaction experimental setups that require neutron detection. The versatile and modular design allows for customizable experimental setups including beta-delayed neutron spectroscopy and (d,n) transfer reactions in normal and inverse kinematics. The neutron energy and prompt-photon discrimination is determined through the time of flight technique. Fully digital data acquisition electronics and integrated triggering logic enables some VANDLE modules to achieve an intrinsic efficiency over 70% for 300-keV neutrons, measured through two different methods. A custom Geant4 simulation models aspectsmore » of the detector array and the experimental setups to determine efficiency and detector response. Lastly, a low detection threshold, due to the trigger logic and digitizing data acquisition, allowed us to measure the light-yield response curve from elastically scattered carbon nuclei inside the scintillating plastic from incident neutrons with kinetic energies below 2 MeV.« less

Profiler - A Fast and Versatile New Program for Decomposing Galaxy Light Profiles

NASA Astrophysics Data System (ADS)

Ciambur, Bogdan C.

2016-12-01

I introduce Profiler, a user-friendly program designed to analyse the radial surface brightness profiles of galaxies. With an intuitive graphical user interface, Profiler can accurately model galaxies of a broad range of morphological types, with various parametric functions routinely employed in the field (Sérsic, core-Sérsic, exponential, Gaussian, Moffat, and Ferrers). In addition to these, Profiler can employ the broken exponential model for disc truncations or anti-truncations, and two special cases of the edge-on disc model: along the disc's major or minor axis. The convolution of (circular or elliptical) models with the point spread function is performed in 2D, and offers a choice between Gaussian, Moffat or a user-provided profile for the point spread function. Profiler is optimised to work with galaxy light profiles obtained from isophotal measurements, which allow for radial gradients in the geometric parameters of the isophotes, and are thus often better at capturing the total light than 2D image-fitting programs. Additionally, the 1D approach is generally less computationally expensive and more stable. I demonstrate Profiler's features by decomposing three case-study galaxies: the cored elliptical galaxy NGC 3348, the nucleated dwarf Seyfert I galaxy Pox 52, and NGC 2549, a double-barred galaxy with an edge-on, truncated disc.

Digital pulse processing in Mössbauer spectroscopy

NASA Astrophysics Data System (ADS)

Veiga, A.; Grunfeld, C. M.

2014-04-01

In this work we present some advances towards full digitization of the detection subsystem of a Mössbauer transmission spectrometer. We show how, using adequate instrumentation, preamplifier output of a proportional counter can be digitized with no deterioration in spectrum quality, avoiding the need of a shaping amplifier. A pipelined architecture is proposed for a digital processor, which constitutes a versatile platform for the development of pulse processing techniques. Requirements for minimization of the analog processing are considered and experimental results are presented.

The Music of the Spheres

ERIC Educational Resources Information Center

Lewicki, Martin; Hughes, Stephen

2012-01-01

This article describes a method for making a spectroscope from scrap materials, i.e. a fragment of compact disc, a cardboard box, a tube and a digital camera to record the spectrum. An image processing program such as ImageJ can be used to calculate the wavelength of emission and absorption lines from the digital photograph. Multiple images of a…

Digital particle image velocimetry measurements of the downwash distribution of a desert locust Schistocerca gregaria

PubMed Central

Bomphrey, Richard J; Taylor, Graham K; Lawson, Nicholas J; Thomas, Adrian L.R

2005-01-01

Actuator disc models of insect flight are concerned solely with the rate of momentum transfer to the air that passes through the disc. These simple models assume that an even pressure is applied across the disc, resulting in a uniform downwash distribution. However, a correction factor, k, is often included to correct for the difference in efficiency between the assumed even downwash distribution, and the real downwash distribution. In the absence of any empirical measurements of the downwash distribution behind a real insect, the values of k used in the literature have been necessarily speculative. Direct measurement of this efficiency factor is now possible, and could be used to compare the relative efficiencies of insect flight across the Class. Here, we use Digital Particle Image Velocimetry to measure the instantaneous downwash distribution, mid-downstroke, of a tethered desert locust (Schistocerca gregaria). By integrating the downwash distribution, we are thereby able to provide the first direct empirical measurement of k for an insect. The measured value of k=1.12 corresponds reasonably well with that predicted by previous theoretical studies. PMID:16849240

A DVD Spectroscope: A Simple, High-Resolution Classroom Spectroscope

ERIC Educational Resources Information Center

Wakabayashi, Fumitaka; Hamada, Kiyohito

2006-01-01

Digital versatile disks (DVDs) have successfully made up an inexpensive but high-resolution spectroscope suitable for classroom experiments that can easily be made with common material and gives clear and fine spectra of various light sources and colored material. The observed spectra can be photographed with a digital camera, and such images can…

On the mode I fracture analysis of cracked Brazilian disc using a digital image correlation method

NASA Astrophysics Data System (ADS)

Abshirini, Mohammad; Soltani, Nasser; Marashizadeh, Parisa

2016-03-01

Mode I of fracture of centrally cracked Brazilian disc was investigated experimentally using a digital image correlation (DIC) method. Experiments were performed on PMMA polymers subjected to diametric-compression load. The displacement fields were determined by a correlation between the reference and the deformed images captured before and during loading. The stress intensity factors were calculated by displacement fields using William's equation and the least square algorithm. The parameters involved in the accuracy of SIF calculation such as number of terms in William's equation and the region of analysis around the crack were discussed. The DIC results were compared with the numerical results available in literature and a very good agreement between them was observed. By extending the tests up to the critical state, mode I fracture toughness was determined by analyzing the image of specimen captured at the moment before fracture. The results showed that the digital image correlation was a reliable technique for the calculation of the fracture toughness of brittle materials.

Cool Tools for the New Frontier: Technological Advances Help Associates Tell Their Story.

ERIC Educational Resources Information Center

Hersch, James

1998-01-01

Argues that creation of a World Wide Web site that makes good use of the available digital audio and visual technologies can be useful in campus activities planning and advertising. The design of a good Web site and the potential uses of digital video and compact discs are discussed. Costs of these technologies are also outlined. (MSE)

Digital map databases in support of avionic display systems

NASA Astrophysics Data System (ADS)

Trenchard, Michael E.; Lohrenz, Maura C.; Rosche, Henry, III; Wischow, Perry B.

1991-08-01

The emergence of computerized mission planning systems (MPS) and airborne digital moving map systems (DMS) has necessitated the development of a global database of raster aeronautical chart data specifically designed for input to these systems. The Naval Oceanographic and Atmospheric Research Laboratory''s (NOARL) Map Data Formatting Facility (MDFF) is presently dedicated to supporting these avionic display systems with the development of the Compressed Aeronautical Chart (CAC) database on Compact Disk Read Only Memory (CDROM) optical discs. The MDFF is also developing a series of aircraft-specific Write-Once Read Many (WORM) optical discs. NOARL has initiated a comprehensive research program aimed at improving the pilots'' moving map displays current research efforts include the development of an alternate image compression technique and generation of a standard set of color palettes. The CAC database will provide digital aeronautical chart data in six different scales. CAC is derived from the Defense Mapping Agency''s (DMA) Equal Arc-second (ARC) Digitized Raster Graphics (ADRG) a series of scanned aeronautical charts. NOARL processes ADRG to tailor the chart image resolution to that of the DMS display while reducing storage requirements through image compression techniques. CAC is being distributed by DMA as a library of CDROMs.

Digital Radiography

NASA Technical Reports Server (NTRS)

1986-01-01

System One, a digital radiography system, incorporates a reusable image medium (RIM) which retains an image. No film is needed; the RIM is read with a laser scanner, and the information is used to produce a digital image on an image processor. The image is stored on an optical disc. System allows the radiologist to "dial away" unwanted images to compare views on three screens. It is compatible with existing equipment and cost efficient. It was commercialized by a Stanford researcher from energy selective technology developed under a NASA grant.

Site-Specific Pre-Swelling-Directed Morphing Structures of Patterned Hydrogels.

PubMed

Wang, Zhi Jian; Hong, Wei; Wu, Zi Liang; Zheng, Qiang

2017-12-11

Morphing materials have promising applications in various fields, yet how to program the self-shaping process for specific configurations remains a challenge. Herein we show a versatile approach to control the buckling of individual domains and thus the outcome configurations of planar-patterned hydrogels. By photolithography, high-swelling disc gels were positioned in a non-swelling gel sheet; the swelling mismatch resulted in out-of-plain buckling of the disc gels. To locally control the buckling direction, masks with holes were used to guide site-specific swelling of the high-swelling gel under the holes, which built a transient through-thickness gradient and thus directed the buckling during the subsequent unmasked swelling process. Therefore, various configurations of an identical patterned hydrogel can be programmed by the pre-swelling step with different masks to encode the buckling directions of separate domains. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A versatile localization system for microscopic multiparametric analysis of cells.

PubMed

Thaw, H H; Rundquist, I; Johansson, U; Svensson, I; Collins, V P

1983-03-01

A new, simple and relatively inexpensive electronic digital position readout (DPRO) system which can be applied to the rapid localization and recovery of microscopic material is described. It is based upon a commercially available digital position readout system which is routinely utilized by industry for small machine tools and measuring equipment. This has been mounted onto the stage of various microscopic instrumentation to provide X and Y coordinates relative to an arbitrary reference point. The integration of small computers interfaced to scanning interferometric, microdensitometric and fluorescence microscopes were used to demonstrate the reliability, versatility and ease of application of this system to problems of multiparametric measurements and analysis of cultured cells. The system may be expanded and applied to clinical material to obtain automatized, multiparametric measurements of cells in haematology and clinical cytology.

Optical-spectrum-synthesizer design within an all-optical semiconductor gate to reduce waveform distortion induced by carrier-cooling relaxation at sub-Teraherz frequencies

NASA Astrophysics Data System (ADS)

Ueno, Yoshiyasu; Nakamoto, Ryouichi; Sakaguchi, Jun; Suzuki, Rei

2006-12-01

In frequency ranges above 200-300 GHz, the second slowest relaxation in the optical response (such as carrier-cooling relaxation having a time constant of 1-2 ps) of a semiconductor optical amplifier inside the conventional delayed-interference signal-wavelength converter (DISC) scheme is thought to start the distortion of all-optically gated waveforms. In this work, we design a digital optical-spectrum-synthesizer block that is part of the expanded DISC scheme. Our numerically calculated spectra, waveforms, and eye diagrams with assumed pseudorandom digital data pulses indicate that this synthesizer significantly removes strong distortion from the gated waveforms. A signal-to-noise ratio of 20 dB was obtained from our random-data eye diagram, providing proof of effectiveness in principle.

Optic disc detection and boundary extraction in retinal images.

PubMed

Basit, A; Fraz, Muhammad Moazam

2015-04-10

With the development of digital image processing, analysis and modeling techniques, automatic retinal image analysis is emerging as an important screening tool for early detection of ophthalmologic disorders such as diabetic retinopathy and glaucoma. In this paper, a robust method for optic disc detection and extraction of the optic disc boundary is proposed to help in the development of computer-assisted diagnosis and treatment of such ophthalmic disease. The proposed method is based on morphological operations, smoothing filters, and the marker controlled watershed transform. Internal and external markers are used to first modify the gradient magnitude image and then the watershed transformation is applied on this modified gradient magnitude image for boundary extraction. This method has shown significant improvement over existing methods in terms of detection and boundary extraction of the optic disc. The proposed method has optic disc detection success rate of 100%, 100%, 100% and 98.9% for the DRIVE, Shifa, CHASE_DB1, and DIARETDB1 databases, respectively. The optic disc boundary detection achieved an average spatial overlap of 61.88%, 70.96%, 45.61%, and 54.69% for these databases, respectively, which are higher than currents methods.

Deformation Recording Process In Polymer-Metal Bilayers And Its Use For Optical Storage

NASA Astrophysics Data System (ADS)

Cornet, Jean A.

1983-11-01

A non-antireflective polymer-metal bilayer structure, encapsulated inside a closed cons-truction/is used for digital data storage in the Thomson-CSF Gigadisc. In this paper, a simple model is presented for microdeformation recording in the medium. This model enables a good understanding of the readout signal as a function of the recording power and leads to some practical consequences. Useful polymers and metallic layers are identified and the disc performance is reported. It is shown that recording using laser diodes can be performed at bit rate up to 14 Mbits.s-1 with a laser power of 7 mW at the disc entry face, in case of a 1200 rpm disc speed. Moreover a working range of 4 mW, as defined by a 3 dB attenuation, is demonstrated. Discs from pilot production exhibit raw bit error rates at the level of 2.10-5. For usual environmental conditions, the disc behaviour is compatible with shelf-and archival life at scale of 10 years. Finally, the processes for both layers deposition and disc construction are easy and cost effective. It is concluded that Giaadisc can successfully enter today the market place.

Signal-to-noise ratio estimation in digital computer simulation of lowpass and bandpass systems with applications to analog and digital communications, volume 3

NASA Technical Reports Server (NTRS)

Tranter, W. H.; Turner, M. D.

1977-01-01

Techniques are developed to estimate power gain, delay, signal-to-noise ratio, and mean square error in digital computer simulations of lowpass and bandpass systems. The techniques are applied to analog and digital communications. The signal-to-noise ratio estimates are shown to be maximum likelihood estimates in additive white Gaussian noise. The methods are seen to be especially useful for digital communication systems where the mapping from the signal-to-noise ratio to the error probability can be obtained. Simulation results show the techniques developed to be accurate and quite versatile in evaluating the performance of many systems through digital computer simulation.

Large amplitude Fourier transformed ac voltammetry at a rotating disc electrode: a versatile technique for covering Levich and flow rate insensitive regimes in a single experiment.

PubMed

Bano, Kiran; Kennedy, Gareth F; Zhang, Jie; Bond, Alan M

2012-04-14

The theory for large amplitude Fourier transformed ac voltammetry at a rotating disc electrode is described. Resolution of time domain data into dc and ac harmonic components reveals that the mass transport for the dc component is controlled by convective-diffusion, while the background free higher order harmonic components are flow rate insensitive and mainly governed by linear diffusion. Thus, remarkable versatility is available; Levich behaviour of the dc component limiting current provides diffusion coefficient values and access to higher harmonics allows fast electrode kinetics to be probed. Two series of experiments (dc and ac voltammetry) have been required to extract these parameters; here large amplitude ac voltammetry with RDE methodology is used to demonstrate that kinetics and diffusion coefficient information can be extracted from a single experiment. To demonstrate the power of this approach, theoretical and experimental comparisons of data obtained for the reversible [Ru(NH(3))(6)](3+/2+) and quasi-reversible [Fe(CN)(6)](3-/4-) electron transfer processes are presented over a wide range of electrode rotation rates and with different concentrations and electrode materials. Excellent agreement of experimental and simulated data is achieved, which allows parameters such as electron transfer rate, diffusion coefficient, uncompensated resistance and others to be determined using a strategically applied approach that takes into account the different levels of sensitivity of each parameter to the dc or the ac harmonic.

VizieR Online Data Catalog: Tully-Fisher relation for SDSS galaxies (Reyes+, 2011)

NASA Astrophysics Data System (ADS)

Reyes, R.; Mandelbaum, R.; Gunn, J. E.; Pizagno, J.; Lackner, C. N.

2012-05-01

In this paper, we derive scaling relations between photometric observable quantities and disc galaxy rotation velocity Vrot or Tully-Fisher relations (TFRs). Our methodology is dictated by our purpose of obtaining purely photometric, minimal-scatter estimators of Vrot applicable to large galaxy samples from imaging surveys. To achieve this goal, we have constructed a sample of 189 disc galaxies at redshifts z<0.1 with long-slit Hα spectroscopy from Pizagno et al. (2007, Cat. J/AJ/134/945) and new observations. By construction, this sample is a fair subsample of a large, well-defined parent disc sample of ~170000 galaxies selected from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7). (4 data files).

X-ray and multiwavelength insights into the inner structure of high-luminosity disc-like emitters

NASA Astrophysics Data System (ADS)

Luo, B.; Brandt, W. N.; Eracleous, M.; Wu, Jian; Hall, P. B.; Rafiee, A.; Schneider, D. P.; Wu, Jianfeng

2013-02-01

We present X-ray and multiwavelength studies of a sample of eight high-luminosity active galactic nuclei (AGN) with disc-like Hβ emission-line profiles selected from the Sloan Digital Sky Survey Data Release 7. These sources have higher redshift (z ≈ 0.6) than the majority of the known disc-like emitters, and they occupy a largely unexplored space in the luminosity-redshift plane. Seven sources have typical AGN X-ray spectra with power-law photon indices of Γ ≈ 1.4-2.0; two of them show some X-ray absorption (column density NH ≈ 1021-1022 cm-2 for neutral gas). The other source, J0850+4451, has only three hard X-ray photons detected and is probably heavily obscured (NH ≳ 3 × 1023 cm-2). This object is also identified as a low-ionization broad absorption line (BAL) quasar based on Mg II λ2799 absorption; it is the first disc-like emitter reported that is also a BAL quasar. The infrared-to-ultraviolet (UV) spectral energy distributions (SEDs) of these eight sources are similar to the mean SEDs of typical quasars with a UV `bump', suggestive of standard accretion discs radiating with high efficiency, which differs from low-luminosity disc-like emitters. Studies of the X-ray-to-optical power-law slope parameters (αOX) indicate that there is no significant excess X-ray emission in these high-luminosity disc-like emitters. Energy budget analysis suggests that for disc-like emitters in general, the inner disc must illuminate and ionize the outer disc efficiently (≈15 per cent of the nuclear ionizing radiation is required on average) via direct illumination and/or scattering. Warped accretion discs are probably needed for direct illumination to work in high-luminosity objects, as their geometrically thin inner discs decrease the amount of direct illumination possible for a flat disc.

Constraints on the temperature inhomogeneity in quasar accretion discs from the ultraviolet-optical spectral variability

NASA Astrophysics Data System (ADS)

Kokubo, Mitsuru

2015-05-01

The physical mechanisms of the quasar ultraviolet (UV)-optical variability are not well understood despite the long history of observations. Recently, Dexter & Agol presented a model of quasar UV-optical variability, which assumes large local temperature fluctuations in the quasar accretion discs. This inhomogeneous accretion disc model is claimed to describe not only the single-band variability amplitude, but also microlensing size constraints and the quasar composite spectral shape. In this work, we examine the validity of the inhomogeneous accretion disc model in the light of quasar UV-optical spectral variability by using five-band multi-epoch light curves for nearly 9 000 quasars in the Sloan Digital Sky Survey (SDSS) Stripe 82 region. By comparing the values of the intrinsic scatter σint of the two-band magnitude-magnitude plots for the SDSS quasar light curves and for the simulated light curves, we show that Dexter & Agol's inhomogeneous accretion disc model cannot explain the tight inter-band correlation often observed in the SDSS quasar light curves. This result leads us to conclude that the local temperature fluctuations in the accretion discs are not the main driver of the several years' UV-optical variability of quasars, and consequently, that the assumption that the quasar accretion discs have large localized temperature fluctuations is not preferred from the viewpoint of the UV-optical spectral variability.

Multimedia in 1992.

ERIC Educational Resources Information Center

Desmarais, Norman

1991-01-01

Reviews current developments in multimedia computing for both the business and consumer markets, including interactive multimedia players; compact disc-interactive (CD-I), including levels of audio quality, various video specifications and visual effects, and software; digital video interactive (DVI); and multimedia personal computers. (LRW)

Sharing from Scratch: How To Network CD-ROM.

ERIC Educational Resources Information Center

Doering, David

1998-01-01

Examines common CD-ROM networking architectures: via existing operating systems (OS), thin server towers, and dedicated servers. Discusses digital video disc (DVD) and non-CD/DVD optical storage solutions and presents case studies of networks that work. (PEN)

Stabilometer Computerized Analog Recording System for Studying Gross Motor Skill Learning

ERIC Educational Resources Information Center

Chasey, William C., Jr.; And Others

1976-01-01

The stabilometer computerized analog recording system (SCARS) provides for storing analog and digital information on a single channel audio tape recorder at lower cost and greater versatility than other systems. (MB)

Translations on Telecommunications Policy, Research and Development, Number 13

DTIC Science & Technology

1977-09-14

9 Aug 77) 4 ATDA Says Research, Development Funds Being Wasted (THE AUSTRALIAN, 15 Aug 77) 5 Digital Unveils New Printer (THE AUSTRALIAN, 22...Argentina Accord 28 BOLIVIA Briefs Bolivian Television Reorganized 29 CUBA New Radio Station for Santa Cruz del Sur ( JUVENTUD REBELDE, 29 Jun 77...II micro- processor. The PM-DS/11 car- tridge disc memory sys- tem provides a double capacity plug-in alter- native to the Digital Equipment

General-Purpose Electronic System Tests Aircraft

NASA Technical Reports Server (NTRS)

Glover, Richard D.

1989-01-01

Versatile digital equipment supports research, development, and maintenance. Extended aircraft interrogation and display system is general-purpose assembly of digital electronic equipment on ground for testing of digital electronic systems on advanced aircraft. Many advanced features, including multiple 16-bit microprocessors, pipeline data-flow architecture, advanced operating system, and resident software-development tools. Basic collection of software includes program for handling many types of data and for displays in various formats. User easily extends basic software library. Hardware and software interfaces to subsystems provided by user designed for flexibility in configuration to meet user's requirements.

Integrated digital metamaterials enables ultra-compact optical diodes

DOE PAGES

Shen, Bing; Polson, Randy; Menon, Rajesh

2015-01-01

We applied nonlinear optimization to design integrated digital metamaterials in silicon for unidirectional energy flow. Two devices, one for each polarization state, were designed, fabricated, and characterized. Both devices offer comparable or higher transmission efficiencies and extinction ratios, are easier to fabricate, exhibit larger bandwidths and are more tolerant to fabrication errors, when compared to alternatives. Furthermore, each device footprint is only 3μm × 3μm, which is the smallest optical diode ever reported. To illustrate the versatility of digital metamaterials, we also designed a polarization-independent optical diode.

Fast, optically controlled Kerr phase shifter for digital signal processing.

PubMed

Li, R B; Deng, L; Hagley, E W; Payne, M G; Bienfang, J C; Levine, Z H

2013-05-01

We demonstrate an optically controlled Kerr phase shifter using a room-temperature 85Rb vapor operating in a Raman gain scheme. Phase shifts from zero to π relative to an unshifted reference wave are observed, and gated operations are demonstrated. We further demonstrate the versatile digital manipulation of encoded signal light with an encoded phase-control light field using an unbalanced Mach-Zehnder interferometer. Generalizations of this scheme should be capable of full manipulation of a digitized signal field at high speed, opening the door to future applications.

Fabrication of a cost-effective polymer nanograting as a disposable plasmonic biosensor using nanoimprint lithography

NASA Astrophysics Data System (ADS)

Mohapatra, Saswat; Kumari, Sudha; Moirangthem, Rakesh S.

2017-07-01

A simple and cost-effective flexible plasmonic sensor is developed using a gold-coated polymer nanograting structure prepared via soft UV nanoimprint lithography. The sub-wavelength nanograting patterns of digital versatile discs were used as a template to prepare the polydimethylsiloxane stamp. The plasmonic sensing substrate was achieved after coating a gold thin film on top of the imprinted nanograting sample. The surface plasmon resonance (SPR) modes excited on the gold-coated nanograting structure appeared as a dip in the reflectance spectrum measured at normal incidence under white light illumination in the ambient air medium. Electromagnetic simulation based on the finite element method was carried out to analyze the excited SPR modes. The simulated result shows very close agreement with the experimental data. The performance of the sensor with respect to changing the surrounding dielectric medium yields a bulk refractive index sensitivity of 788  ±  21 nm per refractive index unit. Further, label-free detection of proteins using a plasmonic sensing substrate was demonstrated by monitoring specific interactions between bovine serum albumin (BSA) and anti-BSA proteins, which gave a detection limit of 123 pg mm-2 with respect to target anti-BSA protein binding. Thus, our proposed plasmonic sensor has potential for the development of an economical and highly sensitive label-free optical biosensing device for biomedical applications.

Spectroscopic and thermal properties of short wavelength metal (II) complexes containing α-isoxazolylazo-β-diketones as co-ligands

NASA Astrophysics Data System (ADS)

Huang, Fuxin; Wu, Yiqun; Gu, Donghong; Gan, Fuxi

2005-10-01

Two new azo dyes of α-isoxazolylazo-β-diketones and their Ni(II) and Cu(II) complexes with blue-violet light wavelength were synthesized using a coupling component, different diazo components and metal (II) ions (Ni 2+ and Cu 2+). Based on the elemental analysis, MS spectra and FT-IR spectral analyses, azo dyes were unequivocally shown to exist as hydrazoketo and azoenol forms which were respectively obtained from the solution forms and from the solid forms. The action of sodium methoxide (NaOMe) on azo dyes in solutions converts hydrazoketo form into azoenol form, so azo dyes are coordinated with metal (II) ions as co-ligands in the azoenol forms. The solubility of all the compounds in common organic solvents such as 2,2,3,3-tetrafluoro-1-propanol (TFP) or chloroform (CHCl 3) and absorption properties of spin-coating thin films were measured. The difference of absorption maxima from the complexes to their ligands was discussed. In addition, the TG analysis of the complexes was also determined, and their thermal stability was evaluated. It is found that these new metal (II) complexes had potential application for high-density digital versatile disc-recordable (HD-DVD-R) system due to their good solubility in organic solvents, reasonable and controllable absorption spectra in blue-violet light region and high thermal stability.

Sparse Data Representation: The Role of Redundancy in Data Processing

DTIC Science & Technology

2005-09-13

directions The Error Diffusion Halftoning Algorithm: Some Recent Stability Results and Applications Beyond Halftoning Dr. Chai Wu Thomas J. Watson Research...digital and analog printers use some form of halftoning ; just look at any picture in a newspaper or magazine under a magnifying glass. Error diffusion is...a popular technique for high quality digital halftoning . The purpose of this talk is to illustrate the versatility of error diffusion with

75 FR 69689 - Privacy Act of 1974; Department of Homeland Security Office of Operations Coordination and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-15

...'s as an identifier and may be shared with the Department); Citizenship; Contact information... facilities in a locked drawer behind a locked door. The records are stored on magnetic disc, tape, digital...

Design of a ``Digital Atlas Vme Electronics'' (DAVE) module

NASA Astrophysics Data System (ADS)

Goodrick, M.; Robinson, D.; Shaw, R.; Postranecky, M.; Warren, M.

2012-01-01

ATLAS-SCT has developed a new ATLAS trigger card, 'Digital Atlas Vme Electronics' (``DAVE''). The unit is designed to provide a versatile array of interface and logic resources, including a large FPGA. It interfaces to both VME bus and USB hosts. DAVE aims to provide exact ATLAS CTP (ATLAS Central Trigger Processor) functionality, with random trigger, simple and complex deadtime, ECR (Event Counter Reset), BCR (Bunch Counter Reset) etc. being generated to give exactly the same conditions in standalone running as experienced in combined runs. DAVE provides additional hardware and a large amount of free firmware resource to allow users to add or change functionality. The combination of the large number of individually programmable inputs and outputs in various formats, with very large external RAM and other components all connected to the FPGA, also makes DAVE a powerful and versatile FPGA utility card.

Cobb Angle Progression in Adolescent Scoliosis Begins at the Intervertebral Disc

PubMed Central

Will, Ryan E; Stokes, Ian A; Qiu, Xing; Walker, Matthew R.; Sanders, James O

2009-01-01

Study Design Longitudinal radiographic study of patients with progressive idiopathic scoliosis. Objective To determine the relative contributions of vertebral and disc wedging to the increase in Cobb angle during 3 phases of adolescent skeletal growth and maturation. Summary of Background Data Both disc wedging and vertebral body wedging are found in progressive scoliosis, but their relative contribution to curve progression over time is unknown. Which occurs first is important for understanding how scoliosis progresses and for developing methods to halt progression. Previous studies have not properly identified maturity and provide conflicting results. Methods Eighteen girls were followed through their adolescent growth spurt with serial spine and hand skeletal age radiographs. Each Cobb angle was divided into disc wedge angles and vertebral wedge angles. The corresponding hand radiographs provided a measure of maturity level, the Digital Skeletal Age (DSA). The disc versus bone contributions to the Cobb angle were then compared during 3 growth phases: prior to the growth spurt, during the growth spurt and after the growth spurt. Significance of relative changes was assessed with the Wilcoxon two-sided mean rank test. Results Prior to the growth spurt, there was no difference in relative contributions of the disc and the bone (3° vs 0°, p=0.38) to curve progression. During the growth spurt, the mean disc component progressed significantly more than that of the vertebrae (15° vs 0°, p=0.0002). This reversed following the growth spurt with the vertebral component progressing more than the disc (10° vs 0°, p=0.01). Conclusion Adolescent idiopathic scoliosis initially increases through disc wedging during the rapid growth spurt with progressive vertebral wedging occurring later. PMID:19940737

Review of past, present, and future of recording technology

NASA Astrophysics Data System (ADS)

Al-Jibouri, Abdul-Rahman

2003-03-01

The revolution of information storage and recording has been advanced significantly over the past two decades. Since the development of computers in early 1950s by IBM, the data (information) was stored on magnetic disc by inducing magnetic flux to define the pit direction. The first disc was developed by IBM with diameter of 25inch to store around 10 kByte. After four decades, the disc drive has become more advanced by reducing the drive size, increasing ariel density and cost reduction. The introduction of new computer operating systems and the Internet resulted in the need to develop high ariel density in the 1990s. Therefore, the disc drive manufacturers were pushed harder to develop new technologies at low cost to survive the competitive market. The disc drives, which are based on media (where the data/information is stored) and the head (which will write and read data/information). The head and disc are separated and with the current technology the spacing between the disc and head is about 40nm. A new technology based on magnetic recording was developed to serve the audio market. This technology is called magnetic type, it is similar to the disc drive, but the media is based on tape rather than rigid disc. Another difference being the head and media are in direct contact. Magnetic tape was developed for audio application and a few years later this technology was extended to allow and accept another technology, called video. This allows consumers to record and view movies in their home. The magnetic tape also used the computer industries for back up data. Magnetic tape is still used in computers and has advanced further over the past decade, companies like Quantum Corp has developed digital linear tape.

Catalog of US GeoData

USGS Publications Warehouse

,

1990-01-01

The development of geographic information systems (GIS) is a rapidly growing industry that supports natural resources, studies, land management, environmental analysis, and urban and transporation planning. The increasing use of computers for storing and analyzing earth science information has greatly expanded the demand for digital cartographic and geographic data. Digital cartography involves the collection, storage, processing, analysis, and display of map data with the aid of computers. The U.S. Geological Survey (USGS), the Nation's largest earth science research agency, through its National Mapping Program, has expanded digital cartography operations to include the collection of elevation, planimetric, land use and land cover, and geographic names information in digital form. This digital information is available on 9-track magnetic tapes and, in the case of 1:2,000,000-scale planimetric digital line graph data, in Compact Disc Read Only Memory (CD-ROM) format. Digital information can be used with all types of geographic and land information systems.

Ask Dr. Sue.

ERIC Educational Resources Information Center

Aronson, Susan S.

1990-01-01

Infant and Child First Aid Training is recommended over CPR for child caregivers. Digital thermometers are considered more reliable, safer, and more versatile than other thermometers. Super-absorbent, disposable diapers are recommended as superior to cloth diapers for sanitary and health reasons. (SH)

Comparison of optical coherence tomography and fundus photography for measuring the optic disc size.

PubMed

Neubauer, Aljoscha S; Krieglstein, Tina R; Chryssafis, Christos; Thiel, Martin; Kampik, Anselm

2006-01-01

To assess the agreement and repeatability of optic nerve head (ONH) size measurements by optical coherence tomography (OCT) as compared to conventional planimetry of fundus photographs in normal eyes. For comparison with planimetry the absolute size of the ONH of 25 eyes from 25 normal subjects were measured by both OCT and digital fundus photography (Zeiss FF camera 450). Repeatability of automated Stratus OCT measurements were investigated by repeatedly measuring the optic disc in five normal subjects. Mean disc size was 1763 +/- 186 vertically and 1632 +/- 160 microm horizontally on planimetry. On OCT, values of 1772 +/- 317 microm vertically (p = 0.82) and a significantly smaller horizontal diameter of 1492 +/- 302 microm (p = 0.04) were obtained. The 95% limits of agreement were (-546 microm; +527 microm) for vertical and (-502 microm; +782 microm) for horizontal planimetric compared to OCT measurements. In some cases large discrepancies existed. Repeatability of automatic measurements of the optic disc by OCT was moderately good with intra-class correlation coefficients (ICC) of 0.78 horizontally and 0.83 vertically. The coefficient of repeatability indicating instrument precision was 80 microm for horizontal and 168 microm for vertical measurements. OCT can be used to determine optic disc margins in moderate agreement with planimetry in normal subjects. However, in some cases significant disagreement with photographic assessment may occur making manual inspection advisable. Automatic disc detection by OCT is moderately repeatable.

78 FR 52553 - Privacy Act of 1974; Department of Homeland Security/ALL-035 Common Entity Index Prototype System...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-23

... data elements: Full Name; Alias(es); Gender; Date of Birth; Country of Birth; Country of Citizenship... locked drawer behind a locked door. The records may be stored on magnetic disc, tape, or digital media...

New Styles, New Technologies, New Possibilities in Jazz.

ERIC Educational Resources Information Center

Kuzmich, John, Jr.

1989-01-01

Focuses on the growth of jazz-related ensembles and jazz education. Covers trends that parallel technological developments including electronic keyboards, Musical Instrument Digital Interface (MIDI) systems, the computer, computer assisted instruction, interactive video, and the compact disc. Urges teachers to update their knowledge and experience…

Digital pressure transducer for use at high temperatures

DOEpatents

Karplus, Henry H. B.

1981-01-01

A digital pressure sensor for measuring fluid pressures at relatively high temperatures includes an electrically conducting fiber coupled to the fluid by a force disc that causes tension in the fiber to be a function of fluid pressure. The tension causes changes in the mechanical resonant frequency of the fiber, which is caused to vibrate in a magnetic field to produce an electrical signal from a positive-feedback amplifier at the resonant frequency. A count of this frequency provides a measure of the fluid pressure.

Digital pressure transducer for use at high temperatures

DOEpatents

Karplus, H.H.B.

A digital pressure sensor for measuring fluid pressures at relatively high temperatures includes an electrically conducting fiber coupled to the fluid by a force disc that causes tension in the fiber to be a function of fluid pressure. The tension causes changes in the mechanical resonant frequency of the fiber, which is caused to vibrate in a magnetic field to produce an electrical signal from a positive-feedback amplifier at the resonant frequency. A count of this frequency provides a measure of the fluid pressure.

Measurement of the traction force of biological cells by digital holography

PubMed Central

Yu, Xiao; Cross, Michael; Liu, Changgeng; Clark, David C.; Haynie, Donald T.; Kim, Myung K.

2011-01-01

The traction force produced by biological cells has been visualized as distortions in flexible substrata. We have utilized quantitative phase microscopy by digital holography (DH-QPM) to study the wrinkling of a silicone rubber film by motile fibroblasts. Surface deformation and the cellular traction force have been measured from phase profiles in a direct and straightforward manner. DH-QPM is shown to provide highly efficient and versatile means for quantitatively analyzing cellular motility. PMID:22254175

Only marginal alignment of disc galaxies

NASA Astrophysics Data System (ADS)

Andrae, René; Jahnke, Knud

2011-12-01

Testing theories of angular-momentum acquisition of rotationally supported disc galaxies is the key to understanding the formation of this type of galaxies. The tidal-torque theory aims to explain this acquisition process in a cosmological framework and predicts positive autocorrelations of angular-momentum orientation and spiral-arm handedness, i.e. alignment of disc galaxies, on short distance scales of 1 Mpc h-1. This disc alignment can also cause systematic effects in weak-lensing measurements. Previous observations claimed discovering these correlations but are overly optimistic in the reported level of statistical significance of the detections. Errors in redshift, ellipticity and morphological classifications were not taken into account, although they have a significant impact. We explain how to rigorously propagate all the important errors through the estimation process. Analysing disc galaxies in the Sloan Digital Sky Survey (SDSS) data base, we find that positive autocorrelations of spiral-arm handedness and angular-momentum orientations on distance scales of 1 Mpc h-1 are plausible but not statistically significant. Current data appear not good enough to constrain parameters of theory. This result agrees with a simple hypothesis test in the Local Group, where we also find no evidence for disc alignment. Moreover, we demonstrate that ellipticity estimates based on second moments are strongly biased by galactic bulges even for Scd galaxies, thereby corrupting correlation estimates and overestimating the impact of disc alignment on weak-lensing studies. Finally, we discuss the potential of future sky surveys. We argue that photometric redshifts have too large errors, i.e. PanSTARRS and LSST cannot be used. Conversely, the EUCLID project will not cover the relevant redshift regime. We also discuss the potentials and problems of front-edge classifications of galaxy discs in order to improve the autocorrelation estimates of angular-momentum orientation.

Effects of A Novel Disc Formulation on Dry Mouth Symptoms and Enamel Remineralization in Patients With Hyposalivation: An In Vivo Study.

PubMed

Ho, Jessica; Firmalino, Miracle Vania; Anbarani, Afarin Golabgir; Takesh, Thair; Epstein, Joel; Wilder-Smith, Petra

2017-02-01

The goal of this study was to identify the in vivo effects in patients with hyposalivation of a novel slowly dissolving adhering test disc upon on enamel remineralization, oral biofilm, salivary production, pH and buffering, gingival health, and on self-evaluation of oral well-being. Five subjects with xerostomia wore custom made retainers carrying 5 demineralized enamel chips for periods of 1 week each. In 1 study arm, subjects used the test agent plus oral hygiene self-care; in the other they used oral hygiene self-care only, with a 1 week washout in between arms. The treatment sequence was randomized. Before and after each study arm Plaque Index (PI), Gingival Index (GI) and Sulcus Bleeding Index (mSBI) were recorded. Clinical plaque staining was quantified using digital image analysis. Saliva production, pH and buffering capacity were recorded. Subjects completed a self-evaluation questionnaire for oral comfort. Enamel samples underwent standardized Knoop microhardness testing to quantify mineralization status. Plaque presence and clinical Plaque Indices decreased significantly with test agent use (p<0.05). Five-minute saliva production almost doubled 10 and 40 minutes after oral test disc insertion (significant, p<0.05). Salivary pH buffering improved in 4/5 subjects with disc use. All demineralized tooth samples re-hardened intraorally (p>0.05). The discs favorably impacted eating problems and dental sensitivity. Subjects were positive about disc flavor and mouth feel. Using established in vivo techniques, the effects of a novel product in xerostomic patients were evaluated and quantified. The adhering disc facilitated eating, reduced dental sensitivity, improved saliva production and buffering capacity, reduced plaque, and alleviated xerostomia symptoms. Xerostomia management is challenging. A novel dry mouth disc was effective in alleviating dry mouth symptoms.

ITERATIVE SCATTER CORRECTION FOR GRID-LESS BEDSIDE CHEST RADIOGRAPHY: PERFORMANCE FOR A CHEST PHANTOM.

PubMed

Mentrup, Detlef; Jockel, Sascha; Menser, Bernd; Neitzel, Ulrich

2016-06-01

The aim of this work was to experimentally compare the contrast improvement factors (CIFs) of a newly developed software-based scatter correction to the CIFs achieved by an antiscatter grid. To this end, three aluminium discs were placed in the lung, the retrocardial and the abdominal areas of a thorax phantom, and digital radiographs of the phantom were acquired both with and without a stationary grid. The contrast generated by the discs was measured in both images, and the CIFs achieved by grid usage were determined for each disc. Additionally, the non-grid images were processed with a scatter correction software. The contrasts generated by the discs were determined in the scatter-corrected images, and the corresponding CIFs were calculated. The CIFs obtained with the grid and with the software were in good agreement. In conclusion, the experiment demonstrates quantitatively that software-based scatter correction allows restoring the image contrast of a non-grid image in a manner comparable with an antiscatter grid. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Determining the mechanical properties of rat skin with digital image speckle correlation.

PubMed

Guan, E; Smilow, Sarah; Rafailovich, Miriam; Sokolov, Jonathan

2004-01-01

Accurate measurement of the mechanical properties of skin has numerous implications in surgical repair, dermal disorders and the diagnosis and treatment of trauma to the skin. Investigation of facial wrinkle formation, as well as research in the areas of skin aging and cosmetic product assessment can also benefit from alternative methodologies for the measurement of mechanical properties. A noncontact, noninvasive technique, digital image speckle correlation (DISC), has been successfully introduced to measure the deformation field of a skin sample loaded by a material test machine. With the force information obtained from the loading device, the mechanical properties of the skin, such as Young's modulus, linear limitation and material strength, can be calculated using elastic or viscoelastic theory. The DISC method was used to measure the deformation of neonatal rat skin, with and without a glycerin-fruit-oil-based cream under uniaxial tension. Deformation to failure procedure of newborn rat skin was recorded and analyzed. Single skin layer failures were observed and located by finding the strain concentration. Young's moduli of freshly excised rat skin, cream-processed rat skin and unprocessed rat skin, 24 h after excision, were found with tensile tests to be 1.6, 1.4 and 0.7 MPa, respectively. Our results have shown that DISC provides a novel technique for numerous applications in dermatology and reconstructive surgeries. Copyright 2004 S. Karger AG, Basel

Stellar and planetary remnants in digital sky surveys

NASA Astrophysics Data System (ADS)

Girven, Jonathan

Large scale digital sky surveys have produced an unprecedented volume of uniform data covering both vast proportions of the sky and a wide range of wavelength, from the ultraviolet to the near-infrared. The challenge facing astronomers today is how to use this multitude of information to extract trends, outliers and and rare objects. For example, a large sample of single white dwarf stars has the potential to probe the Galaxy through the luminosity function. The aim of this work was to study stellar and planetary remnants in these surveys. In the last few decades, it has been shown that a handful of white dwarfs have remnants of planetary systems around them, in the form of a dusty disc. These are currently providing the best constraints on the composition of extra-solar planetary systems. Finding significant numbers of dusty discs is only possible in large scale digital sky surveys. I ultilised the SDSS DR7 and colour-colour diagrams to and DA white dwarfs from optical photometry. This nearly doubled the number of spectroscopically confirmed DA white dwarfs in the SDSS compared with DR4 [Eisenstein et al., 2006], and introduced nearly 10; 000 photometric-only DA white dwarf candidates. I further cross-matched our white dwarf catalogue with UKIDSS LAS DR8 to carry out the currently largest and deepest untargeted search for low-mass companions to, and dust discs around, DA white dwarfs. Simultaneously, I analyzed Spitzer observations of 15 white dwarfs with metal-polluted atmospheres, all but one having helium-dominated atmospheres. Three of these stars were found to have an infrared excess consistent with a dusty disc. I used the total sample to estimate a typical disc lifetime of log[tdisc(yr)] = 5:6+1:1, which is compatible with the relatively large range estimated from different theoretical models. Subdwarf population synthesis models predicted a vast population of subdwarfs with F to K-type companions, produced in the effcient RLOF formation channel. I used a cross-match of ultraviolet, optical and infrared surveys to search for this unseen population. I select a complementary sample to those found from radial velocity surveys, offering direct tests of binary evolution pathways. Finally, I present a method to use common proper motion white dwarf pairs to constrain the initial-final mass relation, which is extremely uncertain at low masses. In the example I show, one of the stars is a magnetic white dwarf with B ' 6 MG, making this a rare and intriguing system from a magnetic white dwarf formation point of view.

Digital Remix

ERIC Educational Resources Information Center

Roach, Ronald

2010-01-01

There's no doubt laptop programs remain important to many institutions, particularly to those that consider social equity an important value in their technology programs. Now, the transition to mobile computing, which puts smaller and often more versatile portable devices in the marketplace, has inspired college and university administrators to…

Versatile digital micromirror device-based method for the recording of multilevel optical diffractive elements in photosensitive chalcogenide layers (AMTIR-1).

PubMed

Joerg, Alexandre; Vignaux, Mael; Lumeau, Julien

2016-08-01

A new alternative and versatile method for the production of diffractive optical elements (DOEs) with up to four phase levels in AMTIR-1 (Ge₃₃As₁₂Se₅₅) layers is demonstrated. The developed method proposes the use of the photosensitive properties of the layers and a specific in situ optical monitoring coupled with a reverse engineering algorithm to control the trigger points of the writing of the different diffractive patterns. Examples of various volume DOEs are presented.

Design and implementation of a channel decoder with LDPC code

NASA Astrophysics Data System (ADS)

Hu, Diqing; Wang, Peng; Wang, Jianzong; Li, Tianquan

2008-12-01

Because Toshiba quit the competition, there is only one standard of blue-ray disc: BLU-RAY DISC, which satisfies the demands of high-density video programs. But almost all the patents are gotten by big companies such as Sony, Philips. As a result we must pay much for these patents when our productions use BD. As our own high-density optical disk storage system, Next-Generation Versatile Disc(NVD) which proposes a new data format and error correction code with independent intellectual property rights and high cost performance owns higher coding efficiency than DVD and 12GB which could meet the demands of playing the high-density video programs. In this paper, we develop Low-Density Parity-Check Codes (LDPC): a new channel encoding process and application scheme using Q-matrix based on LDPC encoding has application in NVD's channel decoder. And combined with the embedded system portable feature of SOPC system, we have completed all the decoding modules by FPGA. In the NVD experiment environment, tests are done. Though there are collisions between LDPC and Run-Length-Limited modulation codes (RLL) which are used in optical storage system frequently, the system is provided as a suitable solution. At the same time, it overcomes the defects of the instability and inextensibility, which occurred in the former decoding system of NVD--it was implemented by hardware.

Anti-Hassle Chip

NASA Technical Reports Server (NTRS)

1998-01-01

With assistance from NASA's Ames Research Center, the iTV Corporation has developed a full custom microprocessor that enables access to the Internet through a $49 device. The microprocessor is supported with a compliment of design tools for customization and adaptation as either a licensable core or as a complete microprocessor. Other uses include cell phones, DVD (digital versatile disk) players, cable modems, video conferencing equipment, digital cameras, wireless LANs (Local Area Network) and WANs (Wide Area Network). iTV continues to design new, low-cost consumer products.

28 CFR 75.8 - Location of the statement.

Code of Federal Regulations, 2012 CFR

2012-07-01

... that opens upon the viewer's clicking or mousing-over a hypertext link that states, “18 U.S.C. 2257... this section, a digital video disc (DVD) containing multiple depictions is a single matter for which... 29619, May 24, 2005, as amended at 73 FR 77471, Dec. 18, 2008] ...

28 CFR 75.8 - Location of the statement.

Code of Federal Regulations, 2014 CFR

2014-07-01

... that opens upon the viewer's clicking or mousing-over a hypertext link that states, “18 U.S.C. 2257... this section, a digital video disc (DVD) containing multiple depictions is a single matter for which... 29619, May 24, 2005, as amended at 73 FR 77471, Dec. 18, 2008] ...

28 CFR 75.8 - Location of the statement.

Code of Federal Regulations, 2013 CFR

2013-07-01

... that opens upon the viewer's clicking or mousing-over a hypertext link that states, “18 U.S.C. 2257... this section, a digital video disc (DVD) containing multiple depictions is a single matter for which... 29619, May 24, 2005, as amended at 73 FR 77471, Dec. 18, 2008] ...

28 CFR 75.8 - Location of the statement.

Code of Federal Regulations, 2011 CFR

2011-07-01

... that opens upon the viewer's clicking or mousing-over a hypertext link that states, “18 U.S.C. 2257... this section, a digital video disc (DVD) containing multiple depictions is a single matter for which... 29619, May 24, 2005, as amended at 73 FR 77471, Dec. 18, 2008] ...

28 CFR 75.8 - Location of the statement.

Code of Federal Regulations, 2010 CFR

2010-07-01

... that opens upon the viewer's clicking or mousing-over a hypertext link that states, “18 U.S.C. 2257... this section, a digital video disc (DVD) containing multiple depictions is a single matter for which... 29619, May 24, 2005, as amended at 73 FR 77471, Dec. 18, 2008] ...

Multiplex DNA detection of food allergens on a digital versatile disk.

PubMed

Tortajada-Genaro, Luis A; Santiago-Felipe, Sara; Morais, Sergi; Gabaldón, José Antonio; Puchades, Rosa; Maquieira, Ángel

2012-01-11

The development of a DNA microarray method on a digital versatile disk (DVD) is described for the simultaneous detection of traces of hazelnut ( Corylus avellana L.), peanut ( Arachis hypogaea ), and soybean ( Glycine max ) in foods. After DNA extraction, multiplex PCR was set up using 5'-labeled specific primers for Cor a 1, Ar h 2, and Le genes, respectively. Digoxin-labeled PCR products were detected by hybridization with 5'-biotinylated probes immobilized on a streptavidin-modified DVD surface. The reaction product attenuates the signal intensity of the laser that reached the DVD drive used as detector, correlating well with the amount of amplified sequence. Analytical performances showed a detection limit of 1 μg/g and good assay reproducibility (RSD 8%), suitable for the simultaneous detection of the three targeted allergens. The developed methodology was tested with several commercially available foodstuffs, demonstrating its applicability. The results were in good agreement, in terms of sensitivity and reproducibility, with those obtained with ELISA, PCR-gel agarose electrophoresis, and RT-PCR.

Comparison of the intervertebral disc spaces between axial and anterior lean cervical traction.

PubMed

Chung, Chin-Teng; Tsai, Sen-Wei; Chen, Chun-Jung; Wu, Ting-Chung; Wang, David; Lan, Haw-Chang H; Wu, Shyi-Kuen

2009-11-01

The insufficient investigations on the changes of spinal structures during traction prevent further exploring the possible therapeutic mechanism of cervical traction. A blind randomized crossover-design study was conducted to quantitatively compare the intervertebral disc spaces between axial and anterior lean cervical traction in sitting position. A total of 96 radiographic images from the baseline measurements, axial and anterior lean tractions in 32 asymptomatic subjects were digitized for further analysis. The intra- and inter-examiner reliabilities for measuring the intervertebral disc spaces were in good ranges (ICCs = 0.928-0.942). With the application of anterior lean traction, the statistical increases were detected both in anterior and in posterior disc spaces compared to the baseline (0.29 mm and 0.24 mm; both P < 0.01) and axial traction (0.16 mm and 0.35 mm; both P < 0.01). The greater intervertebral disc spaces obtained during anterior lean traction might be associated with the more even distribution of traction forces over the anterior and posterior neck structures. The neck extension moment through mandible that generally occurred in the axial traction could be counteracted by the downward force of head weight during anterior lean traction. This study quantitatively demonstrated that anterior lean traction in sitting position provided more intervertebral disc space enlargements in both anterior and posterior aspects than axial traction did. These findings may serve as a therapeutic reference when cervical traction is suggested.

A Flexible Multiring Concentric Electrode for Non-Invasive Identification of Intestinal Slow Waves

PubMed Central

Ye-Lin, Yiyao

2018-01-01

Developing new types of optimized electrodes for specific biomedical applications can substantially improve the quality of the sensed signals. Concentric ring electrodes have been shown to provide enhanced spatial resolution to that of conventional disc electrodes. A sensor with different electrode sizes and configurations (monopolar, bipolar, etc.) that provides simultaneous records would be very helpful for studying the best signal-sensing arrangement. A 5-pole electrode with an inner disc and four concentric rings of different sizes was developed and tested on surface intestinal myoelectrical recordings from healthy humans. For good adaptation to a curved body surface, the electrode was screen-printed onto a flexible polyester substrate. To facilitate clinical use, it is self-adhesive, incorporates a single connector and can perform dry or wet (with gel) recordings. The results show it to be a versatile electrode that can evaluate the optimal configuration for the identification of the intestinal slow wave and reject undesired interference. A bipolar concentric record with an outer ring diameter of 30 mm, a foam-free adhesive material, and electrolytic gel gave the best results. PMID:29385719

Galaxy Zoo: secular evolution of barred galaxies from structural decomposition of multiband images

NASA Astrophysics Data System (ADS)

Kruk, Sandor J.; Lintott, Chris J.; Bamford, Steven P.; Masters, Karen L.; Simmons, Brooke D.; Häußler, Boris; Cardamone, Carolin N.; Hart, Ross E.; Kelvin, Lee; Schawinski, Kevin; Smethurst, Rebecca J.; Vika, Marina

2018-02-01

We present the results of two-component (disc+bar) and three-component (disc+bar+bulge) multiwavelength 2D photometric decompositions of barred galaxies in five Sloan Digital Sky Survey (SDSS) bands (ugriz). This sample of ∼3500 nearby (z < 0.06) galaxies with strong bars selected from the Galaxy Zoo citizen science project is the largest sample of barred galaxies to be studied using photometric decompositions that include a bar component. With detailed structural analysis, we obtain physical quantities such as the bar- and bulge-to-total luminosity ratios, effective radii, Sérsic indices and colours of the individual components. We observe a clear difference in the colours of the components, the discs being bluer than the bars and bulges. An overwhelming fraction of bulge components have Sérsic indices consistent with being pseudo-bulges. By comparing the barred galaxies with a mass-matched and volume-limited sample of unbarred galaxies, we examine the connection between the presence of a large-scale galactic bar and the properties of discs and bulges. We find that the discs of unbarred galaxies are significantly bluer compared to the discs of barred galaxies, while there is no significant difference in the colours of the bulges. We find possible evidence of secular evolution via bars that leads to the build-up of pseudo-bulges and to the quenching of star formation in the discs. We identify a subsample of unbarred galaxies with an inner lens/oval and find that their properties are similar to barred galaxies, consistent with an evolutionary scenario in which bars dissolve into lenses. This scenario deserves further investigation through both theoretical and observational work.

Digital versus film stereo-photography for assessment of the optic nerve head in glaucoma and glaucoma suspect patients.

PubMed

Hasanreisoglu, Murat; Priel, Ethan; Naveh, Lili; Lusky, Moshe; Weinberger, Dov; Benjamini, Yoav; Gaton, Dan D

2013-03-01

One of the leading methods for optic nerve head assessment in glaucoma remains stereoscopic photography. This study compared conventional film and digital stereoscopy in the quantitative and qualitative assessment of the optic nerve head in glaucoma and glaucoma suspect patients. Fifty patients with glaucoma or suspected glaucoma underwent stereoscopic photography of the optic nerve head with a 35-mm color slide film and a digital camera. Photographs/images were presented in random order to 3 glaucoma specialists for independent analysis using a standardized assessment form. Findings for the following parameters were compared among assessors and between techniques: cup/disc (C/D) ratio, state of the optic rim, presence of peripapillary atrophy and appearance of the retinal nerve fiber layer, blood vessels, and lamina cribrosa. The film-based and image-based diagnoses (glaucoma yes/no) were compared as well. Despite high level of agreement across graders using the same method for the horizontal and vertical C/D ratio, (intraclass correlations 0.80 to 0.83), the agreement across graders was much lower for the other parameters using the same method. Similarly the agreement between the findings of the same grader using either method was high for horizontal and vertical C/D ratio, but low for the other parameters. The latter differences were reflected in the disagreement regarding the final diagnosis: The diagnoses differed by technique for each grader in 18% to 46% of eyes, resulting in 38.5% of eyes diagnosed with glaucoma by film photography that "lost" their diagnosis on the digital images, whereas 18.7% of eyes diagnosed as nonglaucomatous by film photography were considered to have glaucoma on the digital images. Although there is consistency between 35-mm film stereoscopy and digital stereoscopy in determining the cup/disc (C/D) ratio, in all other parameters large differences exist, leading to differences in diagnosis. Differences in capturing images between digital and film photography may lead to loss of information and misdiagnosis. Further studies are needed to determine the reliability of the new digital techniques.

Technology and Interactive Multimedia. Identifying Emerging Issues and Trends in Technology for Special Education.

ERIC Educational Resources Information Center

Ashton, Ray

As part of a 3-year study to identify emerging issues and trends in technology for special education, this paper addresses the role of interactive multimedia, especially the digital, optical compact disc technologies, in providing instructional services to special education students. An overview identifies technological and economic trends,…

Digital One Disc One Compound Method for High Throughput Discovery of Prostate Cancer Targeting Ligands

DTIC Science & Technology

2016-12-01

near-infrared imaging to evaluate in vivo the tumor targeting properties of the prostate cancer ligands on xenograft models, from which in vivo...2007). (13) Rosca, E.V., Gillies, R.J. & Caplan, M.R. Glioblastoma targeting via integrins is concentration dependent. Biotechnol Bioeng 104, 408

Music in Infant-Directed Digital Video Discs: A Content Analysis

ERIC Educational Resources Information Center

Brooks, Wendy Louise

2015-01-01

A rapidly growing industry creates and markets a vast range of screen media products designed specifically for babies and children under the age of three. Marketing of these products targets parents and is based on both implicit and explicit educational claims. Although the majority of products target literacy and numeracy, music presentations are…

Digital One-Disc-One-Compound Method for High-Throughput Discovery of Prostate Cancer-Targeting Ligands

DTIC Science & Technology

2014-10-01

substrate ( microchip ), from which the chemical identity of each compound can be directly recognized by recording its location on the microarray...a Laser Printer”, Angewandte Chemie International Edition 47, 7132-7135 (2008). (6) S. P. Fodor, J. L. Read, M. C. Pirrung, L. Stryer, A. T. Lu and

78 FR 56736 - Certain Digital Media Devices, Including Televisions, Blu-Ray Disc Players, Home Theater Systems...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-13

... Intervenor Status to Google, Inc. AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that the U.S. International Trade Commission has determined not to review an...: Robert Needham, Office of the General Counsel, U.S. International Trade Commission, 500 E Street SW...

Detecting the optic disc boundary in digital fundus images using morphological, edge detection, and feature extraction techniques.

PubMed

Aquino, Arturo; Gegundez-Arias, Manuel Emilio; Marin, Diego

2010-11-01

Optic disc (OD) detection is an important step in developing systems for automated diagnosis of various serious ophthalmic pathologies. This paper presents a new template-based methodology for segmenting the OD from digital retinal images. This methodology uses morphological and edge detection techniques followed by the Circular Hough Transform to obtain a circular OD boundary approximation. It requires a pixel located within the OD as initial information. For this purpose, a location methodology based on a voting-type algorithm is also proposed. The algorithms were evaluated on the 1200 images of the publicly available MESSIDOR database. The location procedure succeeded in 99% of cases, taking an average computational time of 1.67 s. with a standard deviation of 0.14 s. On the other hand, the segmentation algorithm rendered an average common area overlapping between automated segmentations and true OD regions of 86%. The average computational time was 5.69 s with a standard deviation of 0.54 s. Moreover, a discussion on advantages and disadvantages of the models more generally used for OD segmentation is also presented in this paper.

Game On!

ERIC Educational Resources Information Center

Deubel, Patricia

2006-01-01

This article describes digital game-based learning (DGBL), the uniting of educational content with computer or online games, that holds the potential for a wealth of educational applications, if managed properly. DGBL motivates by virtue of being fun. It is versatile, can be used to teach almost any subject or skill, and, when used correctly, is…

NASA Tech Briefs, November/December 1986, Special Edition

NASA Technical Reports Server (NTRS)

1986-01-01

Topics: Computing: The View from NASA Headquarters; Earth Resources Laboratory Applications Software: Versatile Tool for Data Analysis; The Hypercube: Cost-Effective Supercomputing; Artificial Intelligence: Rendezvous with NASA; NASA's Ada Connection; COSMIC: NASA's Software Treasurehouse; Golden Oldies: Tried and True NASA Software; Computer Technical Briefs; NASA TU Services; Digital Fly-by-Wire.

Quantitative determination of radio-opacity: equivalence of digital and film X-ray systems.

PubMed

Nomoto, R; Mishima, A; Kobayashi, K; McCabe, J F; Darvell, B W; Watts, D C; Momoi, Y; Hirano, S

2008-01-01

To evaluate the equivalence of a digital X-ray system (DenOptix) to conventional X-ray film in terms of the measured radio-opacity of known filled-resin materials and the suitability of attenuation coefficient for radio-opacity determination. Discs of five thicknesses (0.5-2.5mm) and step-wedges of each of three composite materials of nominal aluminum-equivalence of 50%, 200% and 450% were used. X-ray images of a set of discs (or step-wedge), an aluminum step-wedge, and a lead block were taken at 65 kV and 10 mA at a focus-film distance of 400 mm for 0.15s and 1.6s using an X-ray film or imaging plate. Radio-opacity was determined as equivalent aluminum thickness and attenuation coefficient. The logarithm of the individual optical density or gray scale value, corrected for background, was plotted against thickness, and the attenuation coefficient determined from the slope. The method of ISO 4049 was used for equivalent aluminum thickness. The equivalent aluminum thickness method is not suitable for materials of low radio-opacity, while the attenuation coefficient method could be used for all without difficulty. The digital system gave attenuation coefficients of greater precision than did film, but the use of automatic gain control (AGC) distorted the outcome unusably. Attenuation coefficient is a more precise and generally applicable approach to the determination of radio-opacity. The digital system was equivalent to film but with less noise. The use of AGC is inappropriate for such determinations.

Design limitations of Bryan disc arthroplasty.

PubMed

Fong, Shee Yan; DuPlessis, Stephan J; Casha, Steven; Hurlbert, R John

2006-01-01

Disc arthroplasty is gaining momentum as a surgical procedure in the treatment of spinal degenerative disease. Results must be carefully scrutinized to recognize benefits as well as limitations. The aim of this study was to investigate factors associated with segmental kyphosis after Bryan disc replacement. Prospective study of a consecutively enrolled cohort of 10 patients treated in a single center using the Bryan cervical disc prosthesis for single-level segmental reconstruction in the surgical treatment of cervical radiculopathy and/or myelopathy. Radiographic and quality of life outcome measures. Static and dynamic lateral radiographs were digitally analyzed in patients undergoing Bryan disc arthroplasty throughout a minimum 3-month follow-up period. Observations were compared with preoperative studies looking for predictive factors of postoperative spinal alignment. Postoperative end plate angles through the Bryan disc in the neutral position were kyphotic in 9 of 10 patients. Compared with preoperative end plate angulation there was a mean change of -7 degrees (towards kyphosis) in postoperative end plate alignment (p=.007, 95% confidence interval [CI] -6 degrees to -13 degrees). This correlated significantly with postoperative reduction in posterior vertebral body height of the caudal segment (p=.011, r2=.575) and postoperative functional spine unit (FSU) kyphosis (p=.032, r2=.46). Despite intraoperative distraction, postoperative FSU height was significantly reduced, on average by 1.7 mm (p=.040, 95% CI 0.5-2.8 mm). Asymmetrical end plate preparation occurs because of suboptimal coordinates to which the milling jig is referenced. Although segmental motion is preserved, Bryan disc arthroplasty demonstrates a propensity towards kyphotic orientation through the prosthesis likely as a result of intraoperative lordotic distraction. FSU angulation tends towards kyphosis and FSU height is decreased in the postoperative state from lack of anterior column support. Limitations of Bryan cervical disc arthroplasty should be carefully considered when reconstruction or maintenance of cervical lordosis is desirable.

V/STOLAND avionics system flight-test data on a UH-1H helicopter

NASA Technical Reports Server (NTRS)

Baker, F. A.; Jaynes, D. N.; Corliss, L. D.; Liden, S.; Merrick, R. B.; Dugan, D. C.

1980-01-01

The flight-acceptance test results obtained during the acceptance tests of the V/STOLAND (versatile simplex digital avionics system) digital avionics system on a Bell UH-1H helicopter in 1977 at Ames Research Center are presented. The system provides navigation, guidance, control, and display functions for NASA terminal area VTOL research programs and for the Army handling qualities research programs at Ames Research Center. The acceptance test verified system performance and contractual acceptability. The V/STOLAND hardware navigation, guidance, and control laws resident in the digital computers are described. Typical flight-test data are shown and discussed as documentation of the system performance at acceptance from the contractor.

Performance of the Fully Digital FPGA-Based Front-End Electronics for the GALILEO Array

NASA Astrophysics Data System (ADS)

Barrientos, D.; Bellato, M.; Bazzacco, D.; Bortolato, D.; Cocconi, P.; Gadea, A.; González, V.; Gulmini, M.; Isocrate, R.; Mengoni, D.; Pullia, A.; Recchia, F.; Rosso, D.; Sanchis, E.; Toniolo, N.; Ur, C. A.; Valiente-Dobón, J. J.

2015-12-01

In this work we present the architecture and results of a fully digital Front End Electronics (FEE) read out system developed for the GALILEO array. The FEE system, developed in collaboration with the Advanced Gamma Tracking Array (AGATA) collaboration, is composed of three main blocks: preamplifiers, digitizers and preprocessing electronics. The slow control system contains a custom Linux driver, a dynamic library and a server implementing network services. This work presents the first results of the digital FEE system coupled with a GALILEO germanium detector, which has demonstrated the capability to achieve an energy resolution of 1.530/00 at an energy of 1.33 MeV, similar to the one obtained with a conventional analog system. While keeping a good performance in terms of energy resolution, digital electronics will allow to instrument the full GALILEO array with a versatile system with high integration and low power consumption and costs.

CMOS image sensor with organic photoconductive layer having narrow absorption band and proposal of stack type solid-state image sensors

NASA Astrophysics Data System (ADS)

Takada, Shunji; Ihama, Mikio; Inuiya, Masafumi

2006-02-01

Digital still cameras overtook film cameras in Japanese market in 2000 in terms of sales volume owing to their versatile functions. However, the image-capturing capabilities such as sensitivity and latitude of color films are still superior to those of digital image sensors. In this paper, we attribute the cause for the high performance of color films to their multi-layered structure, and propose the solid-state image sensors with stacked organic photoconductive layers having narrow absorption bands on CMOS read-out circuits.

Next-Generation A/D Sampler ADS3000+ for VLBI2010

NASA Technical Reports Server (NTRS)

Takefuji, Kazuhiro; Takeuchi, Hiroshi; Tsutsumi, Masanori; Koyama, Yasuhiro

2010-01-01

A high-speed A/D sampler, called ADS3000+, has been developed in 2008, which can sample one analog signal up to 4 Gbps to versatile Linux PC. After A/D conversion, the ADS3000+ can perform digital signal processing such as real-time DBBC (Digital Base Band Conversion) and FIR filtering such as simple CW RFI filtering using the installed FPGAs. A 4 Gsps fringe test with the ADS3000+ has been successfully performed. The ADS3000+ will not exclusively be used for VLBI but will also be employed in other applications.

Demonstration of a widely tunable digital supermode distributed Bragg reflector laser as a versatile source for near-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Ciaffoni, L.; Hancock, G.; Hurst, P. L.; Kingston, M.; Langley, C. E.; Peverall, R.; Ritchie, G. A. D.; Whittaker, K. E.

2013-02-01

In this paper we report the characterization of a novel, widely tunable, diode laser source operating over the full telecom L-band (1563-1613 nm), namely the digital supermode distributed Bragg reflector (DS-DBR) laser, and its application to multi-wavelength gas sensing via absorption strategies. The spectroscopic performance of the laser has been assessed by investigating the ro-vibrational spectrum of CO2, and wavelength modulation spectroscopy was accomplished for proof-of-principle sensitive measurements in discrete spectral regions.

Issues in the Design and Development of DVD-Materials for Teacher Training in Counseling.

ERIC Educational Resources Information Center

Miyamoto, Tomohiro; Harnisch, Delwyn L.; Yamada, Tsuneo; Hiraga, Yuko

To cope with dramatically increasing problematic behaviors among primary and secondary school students in Japan, training for counseling skills is considered one of the most important areas in current teacher education. The authors have developed on a DVD (Digital Video Disc) a prototype of counseling materials to assist both in the training of…

78 FR 36573 - Certain Digital Media Devices, Including Televisions, Blu-Ray Disc Players, Home Theater Systems...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-18

... Thereof and Associated Software AGENCY: U.S. International Trade Commission. ACTION: Notice, Institution... thereof and associated software, by reason of infringement of U.S. Patent No. 8,028,323 (``the `323 patent... mobile phones, components thereof and associated software by reason of infringement of one or more of...

CD-I: From Boob Tube to Teacher's Assistant--The Birth of the Smart TV.

ERIC Educational Resources Information Center

Luskin, Bernard J.

1993-01-01

Explains compact disc interactive (CD-I) and discusses possible uses in education. Advances in technology are considered; the current status of CD-I and recent developments are described, including marketing and costs; and future possibilities of CD-I in education are suggested, including digital technology and electronic and optical publishing.…

78 FR 29156 - Certain Digital Media Devices, Including Televisions, Blu-Ray Disc Players, Home Theater Systems...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-17

... AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that the U.S... the complaint or complainant's filing under section 210.8(b) of the Commission's Rules of Practice and Procedure (19 CFR 210.8(b)). FOR FURTHER INFORMATION CONTACT: Lisa R. Barton, Acting Secretary to the...

77 FR 1725 - Certain Blu-Ray Disc Players, Components Thereof and Products Containing Same; Notice of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-11

..., Components Thereof and Products Containing Same; Notice of Institution of Investigation AGENCY: U.S... the U.S. International Trade Commission on December 5, 2011, under section 337 of the Tariff Act of 1930, as amended, 19 U.S.C. 1337, on behalf of Walker Digital, LLC, of Stamford, Connecticut. Letters...

NASA GES DISC New Data Service and Data Management for the Air Quality Community

NASA Technical Reports Server (NTRS)

Wei, Jennifer C.

2017-01-01

President Obama's Big Data Research and Development Initiative seeks to improve our ability to acquire knowledge and discover insights into large and complex collections of digital data. The Big Earth Data Initiative (BEDI) Invests in standardizing and optimizing the collection, management and delivery of U.S. Government's civil Earth observation data.

Geology and mineral resource assessment of the Venezuelan Guayana Shield at 1:500,000 scale; a digital representation of maps published by the U.S. Geological Survey

USGS Publications Warehouse

Schruben, Paul G.; Wynn, J.C.; Gray, Floyd; Cox, D.P.; Sterwart, J.H.; Brooks, W.E.

1997-01-01

This CD-ROM contains vector-based digital maps of the geology and resource assessment of the Venezuela Guayana Shield originally published as paper maps in 1993 in U. S. Geological Survey Bulletin 2062, at a scale of 1:1 million and revised in 1993-95 as separate maps at a scale of 1:500,000. Although the maps on this disc can be displayed at different scales, they are not intended to be used at any scale more detailed than 1:500,000.

Skills and Competencies for Digital Information Management in Africa.

ERIC Educational Resources Information Center

Shibanda, George Gundu

Given the global computerization environment, this paper aspires for the kind of information manager in Africa that is versatile globally, deals with all sorts of technical and resource management issues, and relates at all levels of interaction. The emphasis is on the information professional and manager with a vision of good leadership and…

Adventures with Cell Phones

ERIC Educational Resources Information Center

Kolb, Liz

2011-01-01

Teachers are finding creative ways to turn the basic cell phone from a digital distraction into a versatile learning tool. In this article, the author explains why cell phones are important in learning and suggests rather than banning them that they be integrated into learning. She presents activities that can be done on a basic cell phone with a…

Digital Alchemy for Materials Design: Colloids and Beyond

NASA Astrophysics Data System (ADS)

van Anders, Greg; Klotsa, Daphne; Karas, Andrew; Dodd, Paul; Glotzer, Sharon

Starting with the early alchemists, a holy grail of science has been to make desired materials by manipulating basic building blocks. Building blocks that show promise for assembling new complex materials can be synthesized at the nanoscale with attributes that would astonish the ancient alchemists in their versatility. However, this versatility means that connecting building-block attributes to bulk structure is both necessary for rationally engineering materials and difficult because building block attributes can be altered in many ways. We show how to exploit the malleability of colloidal nanoparticle ``elements'' to quantitatively link building-block attributes to bulk structure through a statistical thermodynamic framework we term ``digital alchemy''. We use this framework to optimize building blocks for a given target structure and to determine which building-block attributes are most important to control for self-assembly, through a set of novel thermodynamic response functions. We thereby establish direct links between the attributes of colloidal building blocks and the bulk structures they form. Moreover, our results give concrete solutions to the more general conceptual challenge of optimizing emergent behaviors in nature and can be applied to other types of matter.

Versatile all-digital time interval measuring system

NASA Astrophysics Data System (ADS)

Vyhlidal, David; Cech, Miroslav

2011-06-01

This paper describes a design and performance of a versatile all-digital time interval measuring system. The measurement method is based on an interpolation principle. In this principle the time interval is first roughly digitized by a coarse counter driven by a high stability reference clock and the fractions between the clock periods are measured by two Time-to-Digital Converter chips TDC-GPX manufactured by Acam messelectronic. Control circuits allow programmable customization of the system to satisfy many applications such as laser range finding, event counting, or time-of-flight measurements in various physics experiments. The system has two reference clocks inputs and two independent channels for measuring start and stop events. Only one 40 MHz reference is required for the measurement. The second reference can be, for example, 1 PPS (Pulse per Second) signal from a GPS (Global Positioning System) to time tag events. Time intervals are measured using the highest resolution mode of the TDC-GPX chips. The resolution of each chip is software programmable and is PLL (Phase Locked Loop) stabilized against temperature and voltage variations. The system can achieve a timing resolution better than 15 ps rms with up to 90 kHz repetition rate. The time interval measurement range is from 0 ps up to 1 second. The power consumption of the whole system is 18 W including an embedded computer board and an LCD (Liquid Crystal Display) screen. The embedded computer controls the whole system, collects and evaluates measurement data and with the display provides a user interface. The system is implemented using commercially available components.

A Versatile Multichannel Digital Signal Processing Module for Microcalorimeter Arrays

NASA Astrophysics Data System (ADS)

Tan, H.; Collins, J. W.; Walby, M.; Hennig, W.; Warburton, W. K.; Grudberg, P.

2012-06-01

Different techniques have been developed for reading out microcalorimeter sensor arrays: individual outputs for small arrays, and time-division or frequency-division or code-division multiplexing for large arrays. Typically, raw waveform data are first read out from the arrays using one of these techniques and then stored on computer hard drives for offline optimum filtering, leading not only to requirements for large storage space but also limitations on achievable count rate. Thus, a read-out module that is capable of processing microcalorimeter signals in real time will be highly desirable. We have developed multichannel digital signal processing electronics that are capable of on-board, real time processing of microcalorimeter sensor signals from multiplexed or individual pixel arrays. It is a 3U PXI module consisting of a standardized core processor board and a set of daughter boards. Each daughter board is designed to interface a specific type of microcalorimeter array to the core processor. The combination of the standardized core plus this set of easily designed and modified daughter boards results in a versatile data acquisition module that not only can easily expand to future detector systems, but is also low cost. In this paper, we first present the core processor/daughter board architecture, and then report the performance of an 8-channel daughter board, which digitizes individual pixel outputs at 1 MSPS with 16-bit precision. We will also introduce a time-division multiplexing type daughter board, which takes in time-division multiplexing signals through fiber-optic cables and then processes the digital signals to generate energy spectra in real time.

Simple and versatile heterodyne whole-field interferometer for phase optics characterization.

PubMed

Silva, D M; Barbosa, E A; Wetter, N U

2012-10-01

A wavefront sensor for thermally induced lens and passive lens characterization based on low-coherence digital speckle interferometry was developed and studied. By illuminating the optical setup with two slightly detuned red diode lasers, whole-field contour interference fringes were generated according to the resulting synthetic wavelength. For fringe pattern visualization the optical setup used the light transmitted through a ground glass plate as object beam. The performance of the sensor was investigated and its versatility was demonstrated by measuring the thermal lens induced in an Er-doped glass sample pumped by a 1.76-W diode laser emitting at 976 nm and by evaluating the wavefront distortion introduced by an ophthalmic progressive lens.

Multiplexed microimmunoassays on a digital versatile disk.

PubMed

Morais, Sergi; Tortajada-Genaro, Luis A; Arnandis-Chover, Tania; Puchades, Rosa; Maquieira, Angel

2009-07-15

Multiplexed microimmunoassays for five critical compounds were developed using a digital versatile disk (DVD) as an analytical support and detecting technology. To this end, coating conjugates were adsorbed on the polycarbonate face of the disk; a pool of specific antibodies, gold labeled secondary antibodies, and silver amplification were addressed for developing the assays. The detection principle is based on the capture of attenuated analog signals with the disk drive that were proportional to optical density of the immunoreaction product. The multiplexed assay achieved detection limits (IC10) of 0.06, 0.25, 0.37, 0.16, and 0.10 microg/L, sensitivities of (IC50) 0.54, 1.54, 2.62, 2.02, and 5.9 microg/L, and dynamic ranges of 2 orders of magnitude for atrazine, chlorpyrifos, metolachlor, sulfathiazole, and tetracycline, respectively. The features of the methodology were verified by analyzing natural waters and compared with reference chromatographic methods, showing its potential for high-throughput multiplexed screening applications. Analytes of different chemical nature (pesticides and antibiotics) were directly quantified without sample treatment or preconcentration in a total time of 30 min with similar sensitivity and selectivity to the ELISA plate format using the same immunoreagents. The multianalyte capabilities of immunoassaying methods developed with digital disk and drive demonstrated the competitiveness to quantify targets that require different sample treatment and instrumentation by chromatographic methods.

A versatile digitally-graded buffer structure for metamorphic device applications

NASA Astrophysics Data System (ADS)

Ma, Yingjie; Zhang, Yonggang; Chen, Xingyou; Gu, Yi; Shi, Yanhui; Ji, Wanyan; Du, Ben

2018-04-01

Exploring more effective buffer schemes for mitigating dislocation deficiencies is the key technology towards higher performance metamorphic devices. Here we demonstrate a versatile metamorphic grading structure consisting of 38-period alternated multilayers of In0.52Al0.48As and In0.82Al0.18As on InP substrate, thicknesses of which in each period were gradually varied in opposite directions from 48.7 and 1.3 nm to 1.3 and 48.7 nm, respectively, akin to a digital alloy. Both preferentially dislocation nucleation and blocking of threading dislocation transmission are observed near the In0.82Al0.18As/In0.52Al0.48As interfaces, which help relax the strain and lower the residual defect density. A 2.6 μm In0.83Ga0.17As pin photodetector is fabricated on this pseudo-substrate, attaining a low dark current density of 2.9  ×  10‑6 A cm‑2 and a high detectivity of 1.8  ×  1010 cmHz1/2W‑1 at room temperature, comparable with the states of the art that on linearly-graded buffer layers. These results indicate such digitally-graded buffer structures are promising for enhancing performances of metamorphic devices, and can be easily generalized to other lattice-mismatched material systems.

1:2,000,000-scale digital line graph data on CD-ROM

USGS Publications Warehouse

,

1995-01-01

Updated U.S. Geological Survey digital line graph (DLG) data collected at a scale of 1:2,000,000 are now available on two compact discs-read only memory (CD-ROM). Each CD-ROM contains digital cartographic data for 49 States and the District of Columbia. The U.S. Virgin Islands, Puerto Rico, and Alaska will be ready within the next year. These DLG data were originally collected from maps published in 1970. Extensive revisions have been made and no data source more than 5 years old was used in this update. In addition, text files containing information such as place names and population have been added for the first time. The records in these text files can be related to corresponding features in the DLG data files. Metadata that comply with the Federal Geographic Data Committee Content Standards for Digital Geospatial Metadata are included for each category of DLG data.

Binary centrifugal microfluidics enabling novel, digital addressable functions for valving and routing.

PubMed

Wang, Guanghui; Tan, Jie; Tang, Minghui; Zhang, Changbin; Zhang, Dongying; Ji, Wenbin; Chen, Junhao; Ho, Ho-Pui; Zhang, Xuping

2018-03-16

Centrifugal microfluidics or lab-on-a-disc (LOAD) is a promising branch of lab-on-a-chip or microfluidics. Besides effective fluid transportation and inherently available density-based sample separation in centrifugal microfluidics, uniform actuation of flow on the disc makes the platform compact and scalable. However, the natural radially outward centrifugal force in a LOAD system limits its capacity to perform complex fluid manipulation steps. In order to increase the fluid manipulation freedom and integration capacity of the LOAD system, we propose a binary centrifugal microfluidics platform. With the help of Euler force, our platform allows free switching of both left and right states based on a rather simple mechanical structure. The periodical switching of state would provide a "clock" signal for a sequence of droplet binary logic operations. With the binary state platform and the "clock" signal, we can accurately handle the droplet separately in each time step with a maximum main frequency of about 10 S s-1 (switching per second). Apart from droplet manipulations such as droplet generation and metering, we also demonstrate a series of droplet logic operations, such as binary valving, droplet routing and digital addressable droplet storage. Furthermore, complex bioassays such as the Bradford assay and DNA purification assay are demonstrated on a binary platform, which is totally impossible for a traditional LOAD system. Our binary platform largely improves the capability for logic operation on the LOAD platform, and it is a simple and promising approach for microfluidic lab-on-a-disc large-scale integration.

3D light scanning macrography.

PubMed

Huber, D; Keller, M; Robert, D

2001-08-01

The technique of 3D light scanning macrography permits the non-invasive surface scanning of small specimens at magnifications up to 200x. Obviating both the problem of limited depth of field inherent to conventional close-up macrophotography and the metallic coating required by scanning electron microscopy, 3D light scanning macrography provides three-dimensional digital images of intact specimens without the loss of colour, texture and transparency information. This newly developed technique offers a versatile, portable and cost-efficient method for the non-invasive digital and photographic documentation of small objects. Computer controlled device operation and digital image acquisition facilitate fast and accurate quantitative morphometric investigations, and the technique offers a broad field of research and educational applications in biological, medical and materials sciences.

A wideband-PCM recorder for the Space Shuttle orbiter

NASA Technical Reports Server (NTRS)

Petit, R. D.

1976-01-01

The Shuttle wideband-PCM recorder accomplishes recording on up to 14 data tracks with analog or digital data inputs. FM multiplexed analog frequencies of up to 2 MHz and digital rates of 1 Mb/s are accommodated at a tape speed of 120 in/s. Recording time in analog mode varies between 4 min for 2 MHz data to 80 min for 100 kHz data. The total digital data storage is 3.44 x 10 to the 9th bits with recording times from 1 hour for 1 Mb/s to 19 hours for 50 Kb/s data in the serial track switching mode. A versatile command decoder and control interface are used for eight primary modes of operation.

Photographic Reading Center of the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT): Methods and Baseline Results

PubMed Central

Fischer, William S.; Wall, Michael; McDermott, Michael P.; Kupersmith, Mark J.; Feldon, Steven E.

2015-01-01

Purpose. To describe the methods used by the Photographic Reading Center (PRC) of the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT) and to report baseline assessments of papilledema severity in participants. Methods. Stereoscopic digital images centered on the optic disc and the macula were collected using certified personnel and photographic equipment. Certification of the camera system included standardization and calibration using a model eye. Lay readers assessed disc photos of all eyes using the Frisén grade and performed quantitative measurements of papilledema. Frisén grades by PRC were compared with site investigator clinical grades. Spearman rank correlations were used to quantify associations among disc features and selected clinical variables. Results. Frisén grades according to the PRC and site investigator's grades, matched exactly in 48% of the study eyes and 42% of the fellow eyes and within one grade in 94% of the study eyes and 92% of the fellow eyes. Frisén grade was strongly correlated (r > 0.65, P < 0.0001) with quantitative measures of disc area. Cerebrospinal fluid pressure was weakly associated with Frisén grade and disc area determinations (r ≤ 0.31). Neither Frisén grade nor any fundus feature was associated with perimetric mean deviation. Conclusions. In a prospective clinical trial, lay readers agreed reasonably well with physicians in assessing Frisén grade. Standardization of camera systems enhanced consistency of photographic quality across study sites. Images were affected more by sensors with poor dynamic range than by poor resolution. Frisén grade is highly correlated with quantitative assessment of disc area. (ClinicalTrials.gov number, NCT01003639.) PMID:26024112

Photographic Reading Center of the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT): Methods and Baseline Results.

PubMed

Fischer, William S; Wall, Michael; McDermott, Michael P; Kupersmith, Mark J; Feldon, Steven E

2015-05-01

To describe the methods used by the Photographic Reading Center (PRC) of the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT) and to report baseline assessments of papilledema severity in participants. Stereoscopic digital images centered on the optic disc and the macula were collected using certified personnel and photographic equipment. Certification of the camera system included standardization and calibration using a model eye. Lay readers assessed disc photos of all eyes using the Frisén grade and performed quantitative measurements of papilledema. Frisén grades by PRC were compared with site investigator clinical grades. Spearman rank correlations were used to quantify associations among disc features and selected clinical variables. Frisén grades according to the PRC and site investigator's grades, matched exactly in 48% of the study eyes and 42% of the fellow eyes and within one grade in 94% of the study eyes and 92% of the fellow eyes. Frisén grade was strongly correlated (r > 0.65, P < 0.0001) with quantitative measures of disc area. Cerebrospinal fluid pressure was weakly associated with Frisén grade and disc area determinations (r ≤ 0.31). Neither Frisén grade nor any fundus feature was associated with perimetric mean deviation. In a prospective clinical trial, lay readers agreed reasonably well with physicians in assessing Frisén grade. Standardization of camera systems enhanced consistency of photographic quality across study sites. Images were affected more by sensors with poor dynamic range than by poor resolution. Frisén grade is highly correlated with quantitative assessment of disc area. (ClinicalTrials.gov number, NCT01003639.).

The physical relation between disc and coronal emission in quasars

NASA Astrophysics Data System (ADS)

Lusso, Elisabeta; Risaliti, Guido

2017-12-01

We propose a modified version of the observed non-linear relation between the X-ray (2 keV) and the ultraviolet (2500 Å) emission in quasars (i.e. LX ∝ LUV^γ ) which involves the full width at half-maximum, FWHM, of the broad emission line, i.e. LX ∝ L_UV^γ FWHM^β. By analysing a sample of 550 optically selected non-jetted quasars in the redshift range of 0.36–2.23 from the Sloan Digital Sky Survey cross matched with the XMM-Newton catalogue 3XMM-DR6, we found that the additional dependence of the observed LX ‑ LUV correlation on the FWHM of the MgII broad emission line is statistically significant. Our statistical analysis leads to a much tighter relation with respect to the one neglecting FWHM, and it does not evolve with redshift. We interpret this new relation within an accretion disc corona scenario where reconnection and magnetic loops above the accretion disc can account for the production of the primary X-ray radiation. For a broad line region size depending on the disc luminosity as R_blr ∝ L^0.5 , we find that L_X ∝ L_UV^4/7 FWHM^4/7, which is in very good agreement with the observed correlation.

Adiposity and different types of screen time.

PubMed

Falbe, Jennifer; Rosner, Bernard; Willett, Walter C; Sonneville, Kendrin R; Hu, Frank B; Field, Alison E

2013-12-01

Few prospective studies have examined separate forms of screen time in relation to adiposity. Our objective was to assess independent relations of television, electronic games (video/computer), and digital versatile disc (DVD)/videos and total screen time with change in adolescent BMI. Using data from the 2004, 2006, and 2008 waves of the ongoing Growing up Today Study II, we assessed baseline and 2-year change in reported screen time in relation to concurrent change in BMI among 4287 girls and 3505 boys aged 9 to 16 years in 2004. Gender-specific models adjusted for previous BMI, age, race/ethnicity, growth/development, months between questionnaires, and physical activity. Among girls and boys, each hour per day increase in reported television viewing was associated with a 0.09 increase in BMI (Ps < .001), and each hour per day increase in total screen time was associated with a 0.07 increase among girls and 0.05 increase among boys (Ps < .001). Among girls only, greater baseline television, games, and total screen time and change in DVDs/videos were associated with gains in BMI (Ps < .05). BMI gains associated with change in television and total screen time were stronger among overweight girls than lean girls (Ps-heterogeneity < .001). Television, which remains the steadiest source of food advertising, was most consistently associated with BMI gains. Among girls, electronic games and DVDs/videos were also related to increased BMI, possibly due to influences of product placements and advergames on diet and/or distracted eating. Adolescents, especially overweight adolescents, may benefit from reduced time with multiple types of media.

Adiposity and Different Types of Screen Time

PubMed Central

Rosner, Bernard; Willett, Walter C.; Sonneville, Kendrin R.; Hu, Frank B.; Field, Alison E.

2013-01-01

OBJECTIVE: Few prospective studies have examined separate forms of screen time in relation to adiposity. Our objective was to assess independent relations of television, electronic games (video/computer), and digital versatile disc (DVD)/videos and total screen time with change in adolescent BMI. METHODS: Using data from the 2004, 2006, and 2008 waves of the ongoing Growing up Today Study II, we assessed baseline and 2-year change in reported screen time in relation to concurrent change in BMI among 4287 girls and 3505 boys aged 9 to 16 years in 2004. Gender-specific models adjusted for previous BMI, age, race/ethnicity, growth/development, months between questionnaires, and physical activity. RESULTS: Among girls and boys, each hour per day increase in reported television viewing was associated with a 0.09 increase in BMI (Ps < .001), and each hour per day increase in total screen time was associated with a 0.07 increase among girls and 0.05 increase among boys (Ps < .001). Among girls only, greater baseline television, games, and total screen time and change in DVDs/videos were associated with gains in BMI (Ps < .05). BMI gains associated with change in television and total screen time were stronger among overweight girls than lean girls (Ps-heterogeneity < .001). CONCLUSIONS: Television, which remains the steadiest source of food advertising, was most consistently associated with BMI gains. Among girls, electronic games and DVDs/videos were also related to increased BMI, possibly due to influences of product placements and advergames on diet and/or distracted eating. Adolescents, especially overweight adolescents, may benefit from reduced time with multiple types of media. PMID:24276840

Multidisciplinary approach to the management of children with female genital mutilation (FGM) or suspected FGM: service description and case series.

PubMed

Creighton, Sarah M; Dear, Joanna; de Campos, Claudia; Williams, Louise; Hodes, Deborah

2016-02-29

To describe the first dedicated clinic in the UK for children with suspected or confirmed female genital mutilation (FGM) including referral patterns, clinical findings and subsequent management. A prospective study of all children seen in a dedicated multidisciplinary FGM clinic for children over a 1-year period. Patients aged under 18 years referred for clinical assessment or for a second opinion on Digital Versatile Disc (DVD) images. Data were collected on reasons for referral, demography, genital examination findings including FGM type, and clinical recommendations. 38 children were referred of whom 18 (47%) had confirmed FGM; most frequently type 4 (61%). Social care and police referred 78% of cases. According to UK law FGM had been performed illegally in three cases. Anonymous information given to the police led to the referral of six children, none of whom had had FGM. Mandatory reporting and increased media attention may increase the numbers of referrals of children with suspected FGM. This patient group have complex needs and management in a dedicated multidisciplinary service is essential. Paediatricians and gynaecologists should have the skills to carry out the consultation and detect all types of FGM including type 4 which was the most common type seen in this series. This is the first dedicated FGM service for children in the UK and similar clinics in high-prevalence areas should be established. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

“Digitally Oriented Materials”: Focus on Lithium Disilicate Ceramics

PubMed Central

Ferrari, Marco; Mangano, Francesco Guido; Sorrentino, Roberto

2016-01-01

The present paper was aimed at reporting the state of the art about lithium disilicate ceramics. The physical, mechanical, and optical properties of this material were reviewed as well as the manufacturing processes, the results of in vitro and in vivo investigations related to survival and success rates over time, and hints for the clinical indications in the light of the latest literature data. Due to excellent optical properties, high mechanical resistance, restorative versatility, and different manufacturing techniques, lithium disilicate can be considered to date one of the most promising dental materials in Digital Dentistry. PMID:27635140

Digital Inverter Amine Sensing via Synergistic Responses by n and p Organic Semiconductors.

PubMed

Tremblay, Noah J; Jung, Byung Jun; Breysse, Patrick; Katz, Howard E

2011-11-22

Chemiresistors and sensitive OFETs have been substantially developed as cheap, scalable, and versatile sensing platforms. While new materials are expanding OFET sensing capabilities, the device architectures have changed little. Here we report higher order logic circuits utilizing OFETs sensitive to amine vapors. The circuits depend on the synergistic responses of paired p- and n-channel organic semiconductors, including an unprecedented analyte-induced current increase by the n-channel semiconductor. This represents the first step towards 'intelligent sensors' that utilize analog signal changes in sensitive OFETs to produce direct digital readouts suitable for further logic operations.

Digital Inverter Amine Sensing via Synergistic Responses by n and p Organic Semiconductors

PubMed Central

Tremblay, Noah J.; Jung, Byung Jun; Breysse, Patrick; Katz, Howard E.

2013-01-01

Chemiresistors and sensitive OFETs have been substantially developed as cheap, scalable, and versatile sensing platforms. While new materials are expanding OFET sensing capabilities, the device architectures have changed little. Here we report higher order logic circuits utilizing OFETs sensitive to amine vapors. The circuits depend on the synergistic responses of paired p- and n-channel organic semiconductors, including an unprecedented analyte-induced current increase by the n-channel semiconductor. This represents the first step towards ‘intelligent sensors’ that utilize analog signal changes in sensitive OFETs to produce direct digital readouts suitable for further logic operations. PMID:23754969

78 FR 20680 - Privacy Act of 1974; Department of Homeland Security/U.S. Citizenship and Immigration Services...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-05

... disc, tape, and/or digital media to maintain a real-time copy of the data for disaster recovery purposes. Real-time copies of data are deleted at the same time as the original data. Retrievability... data in USCIS ELIS. Temporary data includes draft account data provided by first-time Applicants in...

A Symposium: Relevant Cue Research, a Program of Systematic Evaluation: Considerations for Sustaining Instructional Design Research Using an Integrated Learning System.

ERIC Educational Resources Information Center

Grabowski, Barbara

An intelligent videodisc system on which comprehensive instructional development research can be conducted has been developed. This integrated learning system combines all other existing media, except objects, using a videodisc, microcomputer, printer, single monitor, hard disc storage with CPU for random access digitized audio, and headphones.…

FPGA platform for MEMS Disc Resonance Gyroscope (DRG) control

NASA Astrophysics Data System (ADS)

Keymeulen, Didier; Peay, Chris; Foor, David; Trung, Tran; Bakhshi, Alireza; Withington, Phil; Yee, Karl; Terrile, Rich

2008-04-01

Inertial navigation systems based upon optical gyroscopes tend to be expensive, large, power consumptive, and are not long lived. Micro-Electromechanical Systems (MEMS) based gyros do not have these shortcomings; however, until recently, the performance of MEMS based gyros had been below navigation grade. Boeing and JPL have been cooperating since 1997 to develop high performance MEMS gyroscopes for miniature, low power space Inertial Reference Unit applications. The efforts resulted in demonstration of a Post Resonator Gyroscope (PRG). This experience led to the more compact Disc Resonator Gyroscope (DRG) for further reduced size and power with potentially increased performance. Currently, the mass, volume and power of the DRG are dominated by the size of the electronics. This paper will detail the FPGA based digital electronics architecture and its implementation for the DRG which will allow reduction of size and power and will increase performance through a reduction in electronics noise. Using the digital control based on FPGA, we can program and modify in real-time the control loop to adapt to the specificity of each particular gyro and the change of the mechanical characteristic of the gyro during its life time.

Program For Optimization Of Nuclear Rocket Engines

NASA Technical Reports Server (NTRS)

Plebuch, R. K.; Mcdougall, J. K.; Ridolphi, F.; Walton, James T.

1994-01-01

NOP is versatile digital-computer program devoloped for parametric analysis of beryllium-reflected, graphite-moderated nuclear rocket engines. Facilitates analysis of performance of engine with respect to such considerations as specific impulse, engine power, type of engine cycle, and engine-design constraints arising from complications of fuel loading and internal gradients of temperature. Predicts minimum weight for specified performance.

General purpose computer programs for numerically analyzing linear ac electrical and electronic circuits for steady-state conditions

NASA Technical Reports Server (NTRS)

Egebrecht, R. A.; Thorbjornsen, A. R.

1967-01-01

Digital computer programs determine steady-state performance characteristics of active and passive linear circuits. The ac analysis program solves the basic circuit parameters. The compiler program solves these circuit parameters and in addition provides a more versatile program by allowing the user to perform mathematical and logical operations.

Study of Interpolated Timing Recovery Phase-Locked Loop with Linearly Constrained Adaptive Prefilter for Higher-Density Optical Disc

NASA Astrophysics Data System (ADS)

Kajiwara, Yoshiyuki; Shiraishi, Junya; Kobayashi, Shoei; Yamagami, Tamotsu

2009-03-01

A digital phase-locked loop (PLL) with a linearly constrained adaptive filter (LCAF) has been studied for higher-linear-density optical discs. LCAF has been implemented before an interpolated timing recovery (ITR) PLL unit in order to improve the quality of phase error calculation by using an adaptively equalized partial response (PR) signal. Coefficient update of an asynchronous sampled adaptive FIR filter with a least-mean-square (LMS) algorithm has been constrained by a projection matrix in order to suppress the phase shift of the tap coefficients of the adaptive filter. We have developed projection matrices that are suitable for Blu-ray disc (BD) drive systems by numerical simulation. Results have shown the properties of the projection matrices. Then, we have designed the read channel system of the ITR PLL with an LCAF model on the FPGA board for experiments. Results have shown that the LCAF improves the tilt margins of 30 gigabytes (GB) recordable BD (BD-R) and 33 GB BD read-only memory (BD-ROM) with a sufficient LMS adaptation stability.

Characterization of the interface between the bulk glass forming alloy Zr{sub 41}Ti{sub 14}Cu{sub 12}Ni{sub 10}Be{sub 23} with pure metals and ceramics

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

Schroers, Jan; Samwer, Konrad; Szuecs, Frigyes

The reaction of the bulk glass forming alloy Zr{sub 41}Ti{sub 14}Cu{sub 12}Ni{sub 10}Be{sub 23} (Vit 1) with W, Ta, Mo, AlN, Al{sub 2}O{sub 3}, Si, graphite, and amorphous carbon was investigated. Vit 1 samples were melted and subsequently solidified after different processing times on discs of the different materials. Sessile drop examinations of the macroscopic wetting of Vit 1 on the discs as a function of temperature were carried out in situ with a digital optical camera. The reactions at the interfaces between the Vit 1 sample and the different disc materials were investigated with an electron microprobe. The structuremore » and thermal stability of the processed Vit 1 samples were examined by x-ray diffraction and differential scanning calorimetry. The results are discussed in terms of possible applications for composite materials. (c) 2000 Materials Research Society.« less

Intraoral scanning systems - a current overview.

PubMed

Zimmermann, M; Mehl, A; Mörmann, W H; Reich, S

2015-01-01

There is no doubt today about the possibilities and potential of digital impression-taking with the aid of intraoral optical impression systems, and the past few years have seen a considerable increase in the range of optical intraoral scanners available on the market. On the strength of numerous innovations and a wider range of indications in orthodontics and implantology, intraoral scanning systems appear to be a highly promising development for the future. Digital impression-taking with intraoral scanners has already shown itself in some respects to be clearly superior to conventional impression- taking. Particularly worthy of mention is the versatile integration of digital impressions into diagnostic and treatment concepts to provide a customizable healthcare solution for the patient. It remains exciting to look forward to future developments that will allow us to observe digital impression-taking--as with other digital applications already established in everyday life--becoming firmly established in the routine of dentistry and dental technology. This article presents an overview of the benefits and limitations of digital impression-taking using intraoral scanning systems, and includes a summary of all the relevant intraoral scanners available on the market at present.

DIGIT survey of far-infrared lines from protoplanetary discs. II. CO

NASA Astrophysics Data System (ADS)

Meeus, Gwendolyn; Salyk, Colette; Bruderer, Simon; Fedele, Davide; Maaskant, Koen; Evans, Neal J.; van Dishoeck, Ewine F.; Montesinos, Benjamin; Herczeg, Greg; Bouwman, Jeroen; Green, Joel D.; Dominik, Carsten; Henning, Thomas; Vicente, Silvia

2013-11-01

CO is an important component of a protoplanetary disc as it is one of the most abundant gas phase species. Furthermore, observations of CO transitions can be used as a diagnostic of the gas, tracing conditions in both the inner and outer disc. We present Herschel/PACS spectroscopy of a sample of 22 Herbig Ae/Be (HAEBEs) and eight T Tauri stars (TTS), covering the pure rotational CO transitions from J = 14 → 13 up to J = 49 → 48. CO is detected in only five HAEBEs, namely AB Aur, HD 36112, HD 97048, HD 100546, and IRS 48, and in four TTS, namely AS 205, S CrA, RU Lup, and DG Tau. The highest transition detected is J = 36 → 35 with Eup of 3669 K, seen in HD 100546 and DG Tau. We construct rotational diagrams for the discs with at least three CO detections to derive Trot and find average temperatures of 270 K for the HAEBEs and 485 K for the TTS. The HD 100546 star requires an extra temperature component at Trot ~ 900-1000 K, suggesting a range of temperatures in its disc atmosphere, which is consistent with thermo-chemical disc models. In HAEBEs, the objects with CO detections all have flared discs in which the gas and dust are thermally decoupled. We use a small model grid to analyse our observations and find that an increased amount of flaring means higher line flux, as it increases the mass in warm gas. CO is not detected in our flat discs as the emission is below the detection limit. We find that HAEBE sources with CO detections have high LUV and strong PAH emission, which is again connected to the heating of the gas. In TTS, the objects with CO detections are all sources with evidence of a disc wind or outflow. For both groups of objects, sources with CO detections generally have high UV luminosity (either stellar in HAEBEs or due to accretion in TTS), but this is not a sufficient condition for the detection of the far-IR CO lines. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendices are available in electronic form at http://www.aanda.org

Digital equalization of time-delay array receivers on coherent laser communications.

PubMed

Belmonte, Aniceto

2017-01-15

Field conjugation arrays use adaptive combining techniques on multi-aperture receivers to improve the performance of coherent laser communication links by mitigating the consequences of atmospheric turbulence on the down-converted coherent power. However, this motivates the use of complex receivers as optical signals collected by different apertures need to be adaptively processed, co-phased, and scaled before they are combined. Here, we show that multiple apertures, coupled with optical delay lines, combine retarded versions of a signal at a single coherent receiver, which uses digital equalization to obtain diversity gain against atmospheric fading. We found in our analysis that, instead of field conjugation arrays, digital equalization of time-delay multi-aperture receivers is a simpler and more versatile approach to accomplish reduction of atmospheric fading.

Early detection of glaucoma using fully automated disparity analysis of the optic nerve head (ONH) from stereo fundus images

NASA Astrophysics Data System (ADS)

Sharma, Archie; Corona, Enrique; Mitra, Sunanda; Nutter, Brian S.

2006-03-01

Early detection of structural damage to the optic nerve head (ONH) is critical in diagnosis of glaucoma, because such glaucomatous damage precedes clinically identifiable visual loss. Early detection of glaucoma can prevent progression of the disease and consequent loss of vision. Traditional early detection techniques involve observing changes in the ONH through an ophthalmoscope. Stereo fundus photography is also routinely used to detect subtle changes in the ONH. However, clinical evaluation of stereo fundus photographs suffers from inter- and intra-subject variability. Even the Heidelberg Retina Tomograph (HRT) has not been found to be sufficiently sensitive for early detection. A semi-automated algorithm for quantitative representation of the optic disc and cup contours by computing accumulated disparities in the disc and cup regions from stereo fundus image pairs has already been developed using advanced digital image analysis methodologies. A 3-D visualization of the disc and cup is achieved assuming camera geometry. High correlation among computer-generated and manually segmented cup to disc ratios in a longitudinal study involving 159 stereo fundus image pairs has already been demonstrated. However, clinical usefulness of the proposed technique can only be tested by a fully automated algorithm. In this paper, we present a fully automated algorithm for segmentation of optic cup and disc contours from corresponding stereo disparity information. Because this technique does not involve human intervention, it eliminates subjective variability encountered in currently used clinical methods and provides ophthalmologists with a cost-effective and quantitative method for detection of ONH structural damage for early detection of glaucoma.

Quantitative comparison of disc rim color in optic nerve atrophy of compressive optic neuropathy and glaucomatous optic neuropathy.

PubMed

Nakano, Eri; Hata, Masayuki; Oishi, Akio; Miyamoto, Kazuaki; Uji, Akihito; Fujimoto, Masahiro; Miyata, Manabu; Yoshimura, Nagahisa

2016-08-01

The purpose was to investigate an objective and quantitative method to estimate the redness of the optic disc neuroretinal rim, and to determine the usefulness of this method to differentiate compressive optic neuropathy (CON) from glaucomatous optic neuropathy (GON). In our study there were 126 eyes: 40 with CON, 40 with normal tension glaucoma (NTG), and 46 normal eyes (NOR). Digital color fundus photographs were assessed for the redness of disc rim color using ImageJ software. We separately measured the intensity of red, green, and blue pixels from RGB images. Three disc color indices (DCIs), which indicate the redness intensity, were calculated through existing formulas. All three DCIs of CON were significantly smaller than those of NOR (P < 0.001). In addition, when compared with NTG, DCIs were also significantly smaller in CON (P < 0.05). A comparison of mild CON and mild NTG (mean deviation (MD) > -6 dB), in which the extent of retinal nerve fiber layer thinning is comparable, the DCIs of mild CON were significantly smaller than those of mild NTG (P < 0.05). In contrast, DCIs did not differ between moderate-to-severe stages of CON and NTG (MD ≤ -6 dB), though the retinal nerve fibers of CON were more severely damaged than those of NTG. To differentiate between mild CON and mild NTG, all AUROCs for the three DCIs were above 0.700. A quantitative and objective assessment of optic disc color was useful in differentiating early-stage CON from GON and NOR.

A Collection of Reprints,

DTIC Science & Technology

1986-01-01

developed an empirical model for calculating the wind shear velocity U,. The wird shear velocity is an indication of aerodynamic roughness at the...Fleming (1976) disc-isses the cause of scale variations. In 1978 a new digital side-scan system (SMS 960) was developed by EG & G which uses...Naval Postgraduate School Monterey, CA 93940 G. Z. Forristall Shell Development Company Houston, Texas 77001 ABSTRACT This paper catalogs and

1995 Joseph E. Whitley, MD, Award. A World Wide Web gateway to the radiologic learning file.

PubMed

Channin, D S

1995-12-01

Computer networks in general, and the Internet specifically, are changing the way information is manipulated in the world at large and in radiology. The goal of this project was to develop a computer system in which images from the Radiologic Learning File, available previously only via a single-user laser disc, are made available over a generic, high-availability computer network to many potential users simultaneously. Using a networked workstation in our laboratory and freely available distributed hypertext software, we established a World Wide Web (WWW) information server for radiology. Images from the Radiologic Learning File are requested through the WWW client software, digitized from a single laser disc containing the entire teaching file and then transmitted over the network to the client. The text accompanying each image is incorporated into the transmitted document. The Radiologic Learning File is now on-line, and requests to view the cases result in the delivery of the text and images. Image digitization via a frame grabber takes 1/30th of a second. Conversion of the image to a standard computer graphic format takes 45-60 sec. Text and image transmission speed on a local area network varies between 200 and 400 kilobytes (KB) per second depending on the network load. We have made images from a laser disc of the Radiologic Learning File available through an Internet-based hypertext server. The images previously available through a single-user system located in a remote section of our department are now ubiquitously available throughout our department via the department's computer network. We have thus converted a single-user, limited functionality system into a multiuser, widely available resource.

A Case Study on the Perceptions of Educators on the Penetration of Personal Learning Environments in Typical Education

ERIC Educational Resources Information Center

Armakolas, Stefanos; Mikroyannidis, Alexander; Panagiotakopoulos, Christos; Panousopoulou, Theofania

2016-01-01

Personal Learning Environments (PLEs) help students manage and take control of their own learning. As such, the PLE promotes self-regulation in learning and allows learners to aggregate, manipulate and share digital artefacts within a flexible and versatile online space. This paper presents a case study in Greece, concerning an investigation about…

The Army Digital Terrain Catalog II (ADTC)

DTIC Science & Technology

2006-06-01

Engineering (Eds.). Readings for Systems Engineering & Engineering Management. Mason, OH: Thomson Customer Publishing, 2004, p. 2. [3] E. von Hippel ...responsive, deployable, agile, versatile, lethal, survivable, and sustainable force. --Former Army Chief of Staff General Eric Shinseki and former...to advance the tenets of Army Transformation. As former Army Chief of Staff General Eric Shinseki and former Army Secretary Thomas White have stated

A Versatile Image Processor For Digital Diagnostic Imaging And Its Application In Computed Radiography

NASA Astrophysics Data System (ADS)

Blume, H.; Alexandru, R.; Applegate, R.; Giordano, T.; Kamiya, K.; Kresina, R.

1986-06-01

In a digital diagnostic imaging department, the majority of operations for handling and processing of images can be grouped into a small set of basic operations, such as image data buffering and storage, image processing and analysis, image display, image data transmission and image data compression. These operations occur in almost all nodes of the diagnostic imaging communications network of the department. An image processor architecture was developed in which each of these functions has been mapped into hardware and software modules. The modular approach has advantages in terms of economics, service, expandability and upgradeability. The architectural design is based on the principles of hierarchical functionality, distributed and parallel processing and aims at real time response. Parallel processing and real time response is facilitated in part by a dual bus system: a VME control bus and a high speed image data bus, consisting of 8 independent parallel 16-bit busses, capable of handling combined up to 144 MBytes/sec. The presented image processor is versatile enough to meet the video rate processing needs of digital subtraction angiography, the large pixel matrix processing requirements of static projection radiography, or the broad range of manipulation and display needs of a multi-modality diagnostic work station. Several hardware modules are described in detail. For illustrating the capabilities of the image processor, processed 2000 x 2000 pixel computed radiographs are shown and estimated computation times for executing the processing opera-tions are presented.

Demosaicing images from colour cameras for digital image correlation

NASA Astrophysics Data System (ADS)

Forsey, A.; Gungor, S.

2016-11-01

Digital image correlation is not the intended use for consumer colour cameras, but with care they can be successfully employed in such a role. The main obstacle is the sparsely sampled colour data caused by the use of a colour filter array (CFA) to separate the colour channels. It is shown that the method used to convert consumer camera raw files into a monochrome image suitable for digital image correlation (DIC) can have a significant effect on the DIC output. A number of widely available software packages and two in-house methods are evaluated in terms of their performance when used with DIC. Using an in-plane rotating disc to produce a highly constrained displacement field, it was found that the bicubic spline based in-house demosaicing method outperformed the other methods in terms of accuracy and aliasing suppression.

Adherence of Candida to complete denture surfaces in vitro: A comparison of conventional and CAD/CAM complete dentures

PubMed Central

Al-mejrad, Lamya A.; Albarrag, Ahmed M.

2017-01-01

PURPOSE The goal of this study was to compare the adhesion of Candida albicans to the surfaces of CAD/CAM and conventionally fabricated complete denture bases. MATERIALS AND METHODS Twenty discs of acrylic resin poly (methyl methacrylate) were fabricated with CAD/CAM and conventional procedures (heat-polymerized acrylic resin). The specimens were divided into two groups: 10 discs were fabricated using the CAD/CAM procedure (Wieland Digital Denture Ivoclar Vivadent), and 10 discs were fabricated using a conventional flasking and pressure-pack technique. Candida colonization was performed on all the specimens using four Candida albicans isolates. The difference in Candida albicans adhesion on the discs was evaluated. The number of adherent yeast cells was calculated by the colony-forming units (CFU) and by Fluorescence microscopy. RESULTS There was a significant difference in the adhesion of Candida albicans to the complete denture bases created with CAD/CAM and the adhesion to those created with the conventional procedure. The CAD/CAM denture bases exhibited less adhesion of Candida albicans than did the denture bases created with the conventional procedure (P<.05). CONCLUSION The CAD/CAM procedure for fabricating complete dentures showed promising potential for reducing the adherence of Candida to the denture base surface. Clinical Implications. Complete dentures made with the CAD/CAM procedure might decrease the incidence of denture stomatitis compared with conventional dentures. PMID:29142649

Adherence of Candida to complete denture surfaces in vitro: A comparison of conventional and CAD/CAM complete dentures.

PubMed

Al-Fouzan, Afnan F; Al-Mejrad, Lamya A; Albarrag, Ahmed M

2017-10-01

The goal of this study was to compare the adhesion of Candida albicans to the surfaces of CAD/CAM and conventionally fabricated complete denture bases. Twenty discs of acrylic resin poly (methyl methacrylate) were fabricated with CAD/CAM and conventional procedures (heat-polymerized acrylic resin). The specimens were divided into two groups: 10 discs were fabricated using the CAD/CAM procedure (Wieland Digital Denture Ivoclar Vivadent), and 10 discs were fabricated using a conventional flasking and pressure-pack technique. Candida colonization was performed on all the specimens using four Candida albicans isolates. The difference in Candida albicans adhesion on the discs was evaluated. The number of adherent yeast cells was calculated by the colony-forming units (CFU) and by Fluorescence microscopy. There was a significant difference in the adhesion of Candida albicans to the complete denture bases created with CAD/CAM and the adhesion to those created with the conventional procedure. The CAD/CAM denture bases exhibited less adhesion of Candida albicans than did the denture bases created with the conventional procedure ( P <.05). The CAD/CAM procedure for fabricating complete dentures showed promising potential for reducing the adherence of Candida to the denture base surface. Clinical Implications. Complete dentures made with the CAD/CAM procedure might decrease the incidence of denture stomatitis compared with conventional dentures.

Geology of the conterminous United States at 1:2,500,000 scale a digital representation of the 1974 P.B. King and H.M. Beikman map

USGS Publications Warehouse

Schruben, Paul G.; Arndt, Raymond E.; Bawiec, Walter J.

1998-01-01

This CD-ROM contains a digital version of the Geologic Map of the United States, originally published at a scale of 1:2,500,000 (King and Beikman, 1974b). It excludes Alaska and Hawaii. In addition to the graphical formats, the map key is included in ASCII text. A geographic information system (GIS) allows combining and overlaying of layers for analysis of spatial relations not readily apparent in the standard paper publication. This disc contains only geology. However, digital data on geology, geophysics, and geochemistry can be combined to create useful derivative products-- for example, see Phillips and others (1993). This CD-ROM contains a copy of the text and figures from Professional Paper 901 by King and Beikman (1974a). This text describes the historical background of the map, details of the compilation process, and limitations to interpretation. The digital version of the text can be searched for keywords or phrases.

Calibrated Tully-Fisher relations for improved estimates of disc rotation velocities

NASA Astrophysics Data System (ADS)

Reyes, R.; Mandelbaum, R.; Gunn, J. E.; Pizagno, J.; Lackner, C. N.

2011-11-01

In this paper, we derive scaling relations between photometric observable quantities and disc galaxy rotation velocity Vrot or Tully-Fisher relations (TFRs). Our methodology is dictated by our purpose of obtaining purely photometric, minimal-scatter estimators of Vrot applicable to large galaxy samples from imaging surveys. To achieve this goal, we have constructed a sample of 189 disc galaxies at redshifts z < 0.1 with long-slit Hα spectroscopy from Pizagno et al. and new observations. By construction, this sample is a fair subsample of a large, well-defined parent disc sample of ˜170 000 galaxies selected from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7). The optimal photometric estimator of Vrot we find is stellar mass M★ from Bell et al., based on the linear combination of a luminosity and a colour. Assuming a Kroupa initial mass function (IMF), we find: log [V80/(km s-1)] = (2.142 ± 0.004) + (0.278 ± 0.010)[log (M★/M⊙) - 10.10], where V80 is the rotation velocity measured at the radius R80 containing 80 per cent of the i-band galaxy light. This relation has an intrinsic Gaussian scatter ? dex and a measured scatter σmeas= 0.056 dex in log V80. For a fixed IMF, we find that the dynamical-to-stellar mass ratios within R80, (Mdyn/M★)(R80), decrease from approximately 10 to 3, as stellar mass increases from M★≈ 109 to 1011 M⊙. At a fixed stellar mass, (Mdyn/M★)(R80) increases with disc size, so that it correlates more tightly with stellar surface density than with stellar mass or disc size alone. We interpret the observed variation in (Mdyn/M★)(R80) with disc size as a reflection of the fact that disc size dictates the radius at which Mdyn/M★ is measured, and consequently, the fraction of the dark matter 'seen' by the gas at that radius. For the lowest M★ galaxies, we find a positive correlation between TFR residuals and disc sizes, indicating that the total density profile is dominated by dark matter on these scales. For the highest M★ galaxies, we find instead a weak negative correlation, indicating a larger contribution of stars to the total density profile. This change in the sense of the correlation (from positive to negative) is consistent with the decreasing trend in (Mdyn/M★)(R80) with stellar mass. In future work, we will use these results to study disc galaxy formation and evolution and perform a fair, statistical analysis of the dynamics and masses of a photometrically selected sample of disc galaxies.

Digital One-Disc-One-Compound Method for High-Throughput Discovery of Prostate Cancer - Targeting Ligands

DTIC Science & Technology

2015-10-01

shown in Fig. 1a, the prepolymer mixture was sandwiched between photo mask and glass slide. Microdiscs were fabricated on the glass substrate through...polymerization of the prepolymer mixture and the acrylated silane under UV exposure. To achieve the more stable microdiscs for peptide synthesis, the...composition of prepolymer mixture was changed to PEG (Polyethylene Glycol)-diacrylate, crosslinker, photo initiator, 2-aminoethylmethacrylate, water

Thermophysical modelling for high-resolution digital terrain models

NASA Astrophysics Data System (ADS)

Pelivan, I.

2018-07-01

A method is presented for efficiently calculating surface temperatures for highly resolved celestial body shapes. A thorough investigation of the necessary conditions leading to reach model convergence shows that the speed of surface temperature convergence depends on factors such as the quality of initial boundary conditions, thermal inertia, illumination conditions, and resolution of the numerical depth grid. The optimization process to shorten the simulation time while increasing or maintaining the accuracy of model results includes the introduction of facet-specific boundary conditions such as pre-computed temperature estimates and pre-evaluated simulation times. The individual facet treatment also allows for assigning other facet-specific properties such as local thermal inertia. The approach outlined in this paper is particularly useful for very detailed digital terrain models in combination with unfavourable illumination conditions such as little-to-no sunlight at all for a period of time as experienced locally on comet 67P/Churyumov-Gerasimenko. Possible science applications include thermal analysis of highly resolved local (landing) sites experiencing seasonal, environment, and lander shadowing. In combination with an appropriate roughness model, the method is very suitable for application to disc-integrated and disc-resolved data. Further applications are seen where the complexity of the task has led to severe shape or thermophysical model simplifications such as in studying surface activity or thermal cracking.

C-reactive protein and chitinase 3-like protein 1 as biomarkers of spatial redistribution of retinal blood vessels on digital retinal photography in patients with diabetic retinopathy.

PubMed

Cekić, Sonja; Cvetković, Tatjana; Jovanović, Ivan; Jovanović, Predrag; Pesić, Milica; Stanković Babić, Gordana; Milenković, Svetislav; Risimić, Dijana

2014-08-20

The aim of the study was to investigate the correlation between the levels of C-reactive protein (CRP) and chitinase 3-like protein 1 (YKL-40) in blood samples with morpohometric parameters of retinal blood vessels in patients with diabetic retinopathy. Blood laboratory examination of 90 patients included the measurement of glycemia, HbA1C, total cholesterol, LDL-C, HDL-C, triglycerides and CRP. Levels of YKL-40 were detected and measured in serum by ELISA (Micro VueYKL-40 EIA Kit, Quidel Corporation, San Diego, USA). YKL-40 correlated positively with diameter and negatively with number of retinal blood vessels. The average number of the blood vessels per retinal zone was significantly higher in the group of patients with mild non-proliferative diabetic retinopathy than in the group with severe form in the optic disc and all five retinal zones. The average outer diameter of the evaluated retinal zones and optic disc vessels was significantly higher in the group with severe compared to the group with mild diabetic retinopathy. Morphological analysis of the retinal vessels on digital fundus photography and correlation with YKL-40 may be valuable for the follow-up of diabetic retinopathy.

Recovering Nimbus Era Observations at the NASA GES DISC

NASA Technical Reports Server (NTRS)

Meyer, D.; Johnson, J.; Esfandiari, A.; Zamkoff, E.; Al-Jazrawi, A.; Gerasimov, I.; Alcott, G.

2017-01-01

Between 1964 and 1978, NASA launched a series of seven Nimbus meteorological satellites which provided Earth observations for 30 years. These satellites, carrying a total of 33 instruments to observe the Earth at visible, infrared, ultraviolet, and microwave wavelengths, revolutionized weather forecasting, provided early observations of ocean color and atmospheric ozone, and prototyped location-based search and rescue capabilities. The Nimbus series paved the way for a number of currently operational systems such as the EOS (Earth Observation System) Terra, Aqua, and Aura platforms. The original data archive includes both magnetic tapes and film media. These media are well past their expected end of life, placing at risk valuable data that are critical to extending the history of Earth observations back in time. GES DISC (Goddard Earth Sciences Data and Information Services Center) has been incorporating these data into a modern online archive by recovering the digital data files from the tapes, and scanning images of the data from film strips. The digital data products were written on obsolete hardware systems in outdated file formats, and in the absence of metadata standards at that time, were often written in proprietary file structures. Through a tedious and laborious process, oft-corrupted data are recovered, and incomplete metadata and documentation are reconstructed.

Maps for the nation: The current federal mapping establishment

USGS Publications Warehouse

North, G.W.

1983-01-01

The U.S. Government annually produces an estimated 53,000 new maps and charts and distributes about 160 million copies. A large number of these maps are produced under the national mapping program, a decentralized Federal/State cooperative approach to mapping the country at standard scales. Circular A-16, issued by the Office of Management and Budget in 1953 and revised in 1967, delegates the mapping responsibilities to various federal agencies. The U.S. Department of the Interior's Geological Survey is the principal federal agency responsible for implementing the national mapping program. Other major federal map producing agencies include the Departments of Agriculture, Commerce, Defense, Housing and Urban Development, and Transportation, and the Tennessee Valley Authority. To make maps and mapping information more readily available, the National Cartographic Information Center was established in 1974 and an expanded National Map Library Depository Program in 1981. The most recent of many technological advances made under the mapping program are in the areas of digital cartography and video disc and optical disc information storage systems. Future trends and changes in the federal mapping program will involve expanded information and customer service operations, further developments in the production and use of digital cartographic data, and consideration of a Federal Mapping Agency. ?? 1983.

Edaq530: A Transparent, Open-End and Open-Source Measurement Solution in Natural Science Education

ERIC Educational Resources Information Center

Kopasz, Katalin; Makra, Peter; Gingl, Zoltan

2011-01-01

We present Edaq530, a low-cost, compact and easy-to-use digital measurement solution consisting of a thumb-sized USB-to-sensor interface and measurement software. The solution is fully open-source, our aim being to provide a viable alternative to professional solutions. Our main focus in designing Edaq530 has been versatility and transparency. In…

Integrating a Hand Held computer and Stethoscope into a Fetal Monitor

PubMed Central

Ahmad Soltani, Mitra

2009-01-01

This article presents procedures for modifying a hand held computer or personal digital assistant (PDA) into a versatile device functioning as an electronic stethoscope for fetal monitoring. Along with functioning as an electronic stethoscope, a PDA can provide a useful information source for a medical trainee. Feedback from medical students, residents and interns suggests the device is well accepted by medical trainees. PMID:20165517

Reducing the Need for Personal Supports among Workers with Autism Using an iPod Touch as an Assistive Technology: Delayed Randomized Control Trial

ERIC Educational Resources Information Center

Gentry, Tony; Kriner, Richard; Sima, Adam; McDonough, Jennifer; Wehman, Paul

2015-01-01

Personal digital assistants (PDAs) are versatile task organizers that hold promise as assistive technologies for people with cognitive-behavioral challenges. This delayed randomized controlled trial compared two groups of adult workers with autism spectrum disorder (ASD) to determine whether the use of an Apple iPod Touch PDA as a vocational…

Optical-to-virial velocity ratios of local disc galaxies from combined kinematics and galaxy-galaxy lensing

NASA Astrophysics Data System (ADS)

Reyes, R.; Mandelbaum, R.; Gunn, J. E.; Nakajima, R.; Seljak, U.; Hirata, C. M.

2012-10-01

In this paper, we measure the optical-to-virial velocity ratios Vopt/V200c of disc galaxies in the Sloan Digital Sky Survey (SDSS) at a mean redshift of = 0.07 and with stellar masses 109 < M* < 1011 M⊙. Vopt/V200c, the ratio of the circular velocity measured at the optical radius of the disc (˜10 kpc) to that at the virial radius of the dark matter halo (˜150 kpc), is a powerful observational constraint on disc galaxy formation. It links galaxies to their dark matter haloes dynamically and constrains the total mass profile of disc galaxies over an order of magnitude in length scale. For this measurement, we combine Vopt derived from the Tully-Fisher relation (TFR) from Reyes et al. with V200c derived from halo masses measured with galaxy-galaxy lensing. In anticipation of this combination, we use similarly selected galaxy samples for both the TFR and lensing analysis. For three M* bins with lensing-weighted mean stellar masses of 0.6, 2.7 and 6.5 × 1010 M⊙, we find halo-to-stellar mass ratios M200c/M* = 41, 23 and 26, with 1σ statistical uncertainties of around 0.1 dex, and Vopt/V200c = 1.27 ± 0.08, 1.39 ± 0.06 and 1.27 ± 0.08 (1σ), respectively. Our results suggest that the dark matter and baryonic contributions to the mass within the optical radius are comparable, if the dark matter halo profile has not been significantly modified by baryons. The results obtained in this work will serve as inputs to and constraints on disc galaxy formation models, which will be explored in future work. Finally, we note that this paper presents a new and improved galaxy shape catalogue for weak lensing that covers the full SDSS Data Release 7 footprint.

In situ measurements of thin films in bovine serum lubricated contacts using optical interferometry.

PubMed

Vrbka, Martin; Křupka, Ivan; Hartl, Martin; Návrat, Tomáš; Gallo, Jiří; Galandáková, Adéla

2014-02-01

The aim of this study is to consider the relevance of in situ measurements of bovine serum film thickness in the optical test device that could be related to the function of the artificial hip joint. It is mainly focussed on the effect of the hydrophobicity or hydrophilicity of the transparent surface and the effect of its geometry. Film thickness measurements were performed using ball-on-disc and lens-on-disc configurations of optical test device as a function of time. Chromatic interferograms were recorded with a high-speed complementary metal-oxide semiconductor digital camera and evaluated with thin film colorimetric interferometry. It was clarified that a chromium layer covering the glass disc has a hydrophobic behaviour which supports the adsorption of proteins contained in the bovine serum solution, thereby a thicker lubricating film is formed. On the contrary, the protein film formation was not observed when the disc was covered with a silica layer having a hydrophilic behaviour. In this case, a very thin lubricating film was formed only due to the hydrodynamic effect. Metal and ceramic balls have no substantial effect on lubricant film formation although their contact surfaces have relatively different wettability. It was confirmed that conformity of contacting surfaces and kinematic conditions has fundamental effect on bovine serum film formation. In the ball-on-disc configuration, the lubricant film is formed predominantly due to protein aggregations, which pass through the contact zone and increase the film thickness. In the more conformal ball-on-lens configuration, the lubricant film is formed predominantly due to hydrodynamic effect, thereby the film thickness is kept constant during measurement.

Diagnosis and Incidence of Spondylosis and Cervical Disc Disorders in the University Clinical Hospital in Olsztyn, in Years 2011–2015

PubMed Central

Włodarczyk, Andrzej; Wojtkiewicz, Joanna

2018-01-01

Background Disorders connected with the musculoskeletal and central nervous system dysfunction are the most significant clinical problem worldwide. Our earlier research has shown that back and spinal disorders and lumbar disc disorders were most frequently diagnosed using MRI scanner at the University Clinical Hospital (UCH) in Olsztyn in years 2011–2015. We have also observed that another two diseases of spinal column, spondylosis and cervical disc disorders, were also very prevalent. The main objective of this work was to analyze the prevalence of spondylosis and cervical disc disorders in the study population diagnosed at UCH in years 2011–2015. Methods The digital database including patients' diagnostic and demographic information was generated based on MRI reports from years 2011–2015 and analyzed using SPSS software. Results Within the study group (n = 13298) the most frequently MRI-diagnosed diseases were musculoskeletal group (M00–M99; n = 7711; 57,98%) and cervical disc disorders (M50; n = 1659; 12,47%) and spondylosis (M47, n = 611; 4,59%). More women (67%) than men (33%) were enrolled in the study, and the largest fraction of the study population was in the range of 51–60 years, with about 1/3 of cases of both diseases diagnosed in early age range of 31–40 years. Conclusion Significant number of patients presenting with either of the spine disorders at the young age of 31–40 years points to the necessity of introducing methods preventing disorders of the vertebral column at younger age, preferably at school age. PMID:29770333

SDSS-IV MaNGA: bulge-disc decomposition of IFU data cubes (BUDDI)

NASA Astrophysics Data System (ADS)

Johnston, Evelyn J.; Häußler, Boris; Aragón-Salamanca, Alfonso; Merrifield, Michael R.; Bamford, Steven; Bershady, Matthew A.; Bundy, Kevin; Drory, Niv; Fu, Hai; Law, David; Nitschelm, Christian; Thomas, Daniel; Roman Lopes, Alexandre; Wake, David; Yan, Renbin

2017-02-01

With the availability of large integral field unit (IFU) spectral surveys of nearby galaxies, there is now the potential to extract spectral information from across the bulges and discs of galaxies in a systematic way. This information can address questions such as how these components built up with time, how galaxies evolve and whether their evolution depends on other properties of the galaxy such as its mass or environment. We present bulge-disc decomposition of IFU data cubes (BUDDI), a new approach to fit the two-dimensional light profiles of galaxies as a function of wavelength to extract the spectral properties of these galaxies' discs and bulges. The fitting is carried out using GALFITM, a modified form of GALFIT which can fit multiwaveband images simultaneously. The benefit of this technique over traditional multiwaveband fits is that the stellar populations of each component can be constrained using knowledge over the whole image and spectrum available. The decomposition has been developed using commissioning data from the Sloan Digital Sky Survey-IV Mapping Nearby Galaxies at APO (MaNGA) survey with redshifts z < 0.14 and coverage of at least 1.5 effective radii for a spatial resolution of 2.5 arcsec full width at half-maximum and field of view of > 22 arcsec, but can be applied to any IFU data of a nearby galaxy with similar or better spatial resolution and coverage. We present an overview of the fitting process, the results from our tests, and we finish with example stellar population analyses of early-type galaxies from the MaNGA survey to give an indication of the scientific potential of applying bulge-disc decomposition to IFU data.

Modulating release of ranibizumab and aflibercept from thiolated chitosan-based hydrogels for potential treatment of ocular neovascularization.

PubMed

Moreno, Miguel; Pow, Poh Yih; Tabitha, Tan Su Teng; Nirmal, Sonali; Larsson, Andreas; Radhakrishnan, Krishna; Nirmal, Jayabalan; Quah, Soo Tng; Geifman Shochat, Susana; Agrawal, Rupesh; Venkatraman, Subbu

2017-08-01

This paper describes the synthesis of thiolated chitosan-based hydrogels with varying degrees of crosslinking that has been utilized to modulate release kinetics of two clinically relevant FDA-approved anti-VEGF protein drugs, ranibizumab and aflibercept. These hydrogels have been fabricated into disc shaped structures for potential use as patches on ocular surface. Protein conformational changes and aggregation after loading and release was evaluated by circular dichroism (CD), steady-state tryptophan fluorescence spectroscopy, electrophoresis and size-exclusion chromatography (SEC). Finally, the capacity of both released proteins to bind to VEGF was tested by ELISA and surface plasmon resonance (SPR) technology. The study demonstrates the versatility of thiolated chitosan-based hydrogels for delivering proteins. The effect of various parameters of the hydrogel on protein release kinetics and mechanism of protein release was studied using the Korsmeyer-Peppas release model. Furthermore, we have studied the stability of released proteins in detail while comparing it with non-entrapped proteins under physiological conditions to understand the effect of formulation conditions on protein stability. The disc-shaped thiolated chitosan-based hydrogels provide a potentially useful platform to deliver ranibizumab and aflibercept for the treatments of ocular diseases such as wet AMD, DME and corneal neovascularization.

Oral-facial-digital syndrome type IX in a patient with Dandy-Walker malformation.

PubMed Central

Nagai, K; Nagao, M; Nagao, M; Yanai, S; Minagawa, K; Takahashi, Y; Takekoshi, Y; Ishizaka, A; Matsuzono, Y; Kobayashi, O; Itagaki, T

1998-01-01

We report a girl with oral, facial, and digital anomalies including multiple alveolar frenula, lobulated tongue with nodules, a posterior cleft palate, hypertelorism, a prominent forehead with a large anterior fontanelle, and postaxial polydactyly in both hands and the right foot, features compatible with the oral-facial-digital syndrome (OFDS). In addition, she had bilateral microphthalmia, optic disc coloboma, and retinal degeneration with partial detachment, thus establishing a diagnosis of OFDS type IX. Dandy-Walker malformation and retrobulbar cysts were observed on MRI. These additional malformations have not been reported in OFDS type IX. The frequent apnoeic spells which occurred immediately after birth were relieved after cystoperitoneal shunt implantation for hydrocephalus. Considering our case and previous reports of OFDS type IX, including two male sibs, a boy born to consanguineous parents, and three females, inheritance is probably autosomal recessive. Images PMID:9598735

Comparison of analytic and iterative digital tomosynthesis reconstructions for thin slab objects

NASA Astrophysics Data System (ADS)

Yun, J.; Kim, D. W.; Ha, S.; Kim, H. K.

2017-11-01

For digital x-ray tomosynthesis of thin slab objects, we compare the tomographic imaging performances obtained from the filtered backprojection (FBP) and simultaneous algebraic reconstruction (SART) algorithms. The imaging performance includes the in-plane molulation-transfer function (MTF), the signal difference-to-noise ratio (SDNR), and the out-of-plane blur artifact or artifact-spread function (ASF). The MTF is measured using a thin tungsten-wire phantom, and the SDNR and the ASF are measured using a thin aluminum-disc phantom embedded in a plastic cylinder. The FBP shows a better MTF performance than the SART. On the contrary, the SART outperforms the FBP with regard to the SDNR and ASF performances. Detailed experimental results and their analysis results are described in this paper. For a more proper use of digital tomosynthesis technique, this study suggests to use a reconstuction algorithm suitable for application-specific purposes.

Flight Test Results for the F-16XL With a Digital Flight Control System

NASA Technical Reports Server (NTRS)

Stachowiak, Susan J.; Bosworth, John T.

2004-01-01

In the early 1980s, two F-16 airplanes were modified to extend the fuselage length and incorporate a large area delta wing planform. These two airplanes, designated the F-16XL, were designed by the General Dynamics Corporation (now Lockheed Martin Tactical Aircraft Systems) (Fort Worth, Texas) and were prototypes for a derivative fighter evaluation program conducted by the United States Air Force. Although the concept was never put into production, the F-16XL prototypes provided a unique planform for testing concepts in support of future high-speed supersonic transport aircraft. To extend the capabilities of this testbed vehicle the F-16XL ship 1 aircraft was upgraded with a digital flight control system. The added flexibility of a digital flight control system increases the versatility of this airplane as a testbed for aerodynamic research and investigation of advanced technologies. This report presents the handling qualities flight test results covering the envelope expansion of the F-16XL with the digital flight control system.

Bridging the Digital Divide between Discrete and Continuous Space-Time Array Data to Enhance Accessibility to and Usability of NASA Earth Sciences Data for the Hydrological Community

NASA Astrophysics Data System (ADS)

Teng, W. L.; Maidment, D. R.; Vollmer, B.; Peters-Lidard, C. D.; Rui, H.; Strub, R.; Whiteaker, T.; Mocko, D. M.; Kirschbaum, D. B.

2012-12-01

A longstanding and significant "Digital Divide" in data representation exists between hydrology and climatology and meteorology. Typically, in hydrology, earth surface features are expressed as discrete spatial objects such as watersheds, river reaches, and point observation sites; and time varying data are contained in time series associated with these spatial objects. Long time histories of data may be associated with a single point or feature in space. In meteorology and climatology, remotely sensed observations and weather and climate model information are expressed as continuous spatial fields, with data sequenced in time from one data file to the next. Hydrology tends to be narrow in space and deep in time, while meteorology and climatology are broad in space and narrow in time. This Divide has been an obstacle, specifically, between the hydrological community, as represented by the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) and relevant data sets at the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC). CUAHSI has developed the Hydrologic Information System (HIS), which is built on international geospatial standards, with one of its aims to bridge the Divide. The opportunity costs of the Divide are high. It has largely prevented the routine access and use of NASA Earth sciences data by the hydrological and, more generally, geospatial community. This presentation describes a recently-begun NASA ACCESS project that addresses the Digital Divide problem. Progress to date is summarized; technical details are provided in a related presentation (Rui et al., Data Reorganization for Optimal Time Series Data Access, Analysis, and Visualization, IN016). Building on prior prototype efforts with EPA BASINS (Better Assessment Science Integrating point and Nonpoint Sources) and CUAHSI HIS, this project focuses on the following approaches to the problems of data discovery, access, and use: (1) Link HIS and GES DISC ontologies to facilitate data service registration in HIS catalog; (2) harvest NASA ECHO catalog with OpenSearch to generalize the solution beyond GES DISC; (3) develop HIS WaterOneFlow Web services for GES DISC data in OGC-compliant WaterML 2.0; (4) reorganize NASA data (land surface model outputs, satellite precipitation and soil moisture data) for optimal access as time series; (5) enhance HIS HydroDesktop client to better handle NASA data; and (6) develop hydrological use cases to guide implementation, and serve as metric for usefulness, of project technologies. This project should significantly extend NASA Earth sciences data to the large and important hydrological user community that has been, heretofore, mostly unable to easily access and use NASA data.

Geologic Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

USGS Publications Warehouse

Kirschbaum, Mark A.; Roberts, Lauara N.R.; Biewick, Laura

2000-01-01

This CD-ROM set contains a geologic assessment of coal deposits of the Colorado Plateau region and new resource estimates for selected assessment units within the Colorado Plateau. Original resource estimates (in-place resources before production) for the 12 priority assessment units of the Colorado Plateau exceed one half trillion short tons of coal in beds greater than 1 ft thick and under less than 6,000 ft of overburden. The coal is high quality and low sulfur, and a portion of these resources will provide future energy production for the Nation. Disc 1, in Portable Document Format, contains results of the assessment in summary and (or) technical reports for 12 priority coal assessment units in the Colorado Plateau and also contains an ArcView Data Publisher project, which is an interactive geographic information system of digital data collected during the assessment. Disc 2 contains stratigraphic data bases for seven of the priority coal assessment areas within the Colorado Plateau region and an ArcView project identical to the ArcView Data Publisher project on disc 1 except that it retains some of the functionality that is disabled in the ArcView Data Publisher program.

Image processing based automatic diagnosis of glaucoma using wavelet features of segmented optic disc from fundus image.

PubMed

Singh, Anushikha; Dutta, Malay Kishore; ParthaSarathi, M; Uher, Vaclav; Burget, Radim

2016-02-01

Glaucoma is a disease of the retina which is one of the most common causes of permanent blindness worldwide. This paper presents an automatic image processing based method for glaucoma diagnosis from the digital fundus image. In this paper wavelet feature extraction has been followed by optimized genetic feature selection combined with several learning algorithms and various parameter settings. Unlike the existing research works where the features are considered from the complete fundus or a sub image of the fundus, this work is based on feature extraction from the segmented and blood vessel removed optic disc to improve the accuracy of identification. The experimental results presented in this paper indicate that the wavelet features of the segmented optic disc image are clinically more significant in comparison to features of the whole or sub fundus image in the detection of glaucoma from fundus image. Accuracy of glaucoma identification achieved in this work is 94.7% and a comparison with existing methods of glaucoma detection from fundus image indicates that the proposed approach has improved accuracy of classification. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The many blades of the β-propeller proteins: conserved but versatile.

PubMed

Chen, Cammy K-M; Chan, Nei-Li; Wang, Andrew H-J

2011-10-01

The β-propeller is a highly symmetrical structure with 4-10 repeats of a four-stranded antiparallel β-sheet motif. Although β-propeller proteins with different blade numbers all adopt disc-like shapes, they are involved in a diverse set of functions, and defects in this family of proteins have been associated with human diseases. However, it has remained ambiguous how variations in blade number could alter the function of β-propellers. In addition to the regularly arranged β-propeller topology, a recently discovered β-pinwheel propeller has been found. Here, we review the structural and functional diversity of β-propeller proteins, including β-pinwheels, as well as recent advances in the typical and atypical propeller structures. Copyright © 2011 Elsevier Ltd. All rights reserved.

Remote sensing of Earth's atmosphere and surface using a digital array scanned interferometer: A new type of imaging spectrometer

NASA Technical Reports Server (NTRS)

Hammer, Philip D.; Valero, Francisco P. J.; Peterson, David L.; Smith, William Hayden

1991-01-01

The capabilities of the digital array scanned interferometer (DASI) class of instruments for measuring terrestrial radiation fields over the visible to mid-infrared are evaluated. DASI's are capable of high throughput, sensitivity and spectral resolution and have the potential for field-of-view spatial discrimination (an imaging spectrometer). The simplicity of design and operation of DASI's make them particularly suitable for field and airborne platform based remote sensing. The long term objective is to produce a versatile field instrument which may be applied toward a variety of atmospheric and surface studies. The operation of DASI and its advantages over other spectrometers are discussed.

Development of a digital-micromirror-device-based multishot snapshot spectral imaging system.

PubMed

Wu, Yuehao; Mirza, Iftekhar O; Arce, Gonzalo R; Prather, Dennis W

2011-07-15

We report on the development of a digital-micromirror-device (DMD)-based multishot snapshot spectral imaging (DMD-SSI) system as an alternative to current piezostage-based multishot coded aperture snapshot spectral imager (CASSI) systems. In this system, a DMD is used to implement compressive sensing (CS) measurement patterns for reconstructing the spatial/spectral information of an imaging scene. Based on the CS measurement results, we demonstrated the concurrent reconstruction of 24 spectral images. The DMD-SSI system is versatile in nature as it can be used to implement independent CS measurement patterns in addition to spatially shifted patterns that piezostage-based systems can offer. © 2011 Optical Society of America

Rapidly deployable emergency communication system

DOEpatents

Gladden, Charles A.; Parelman, Martin H.

1979-01-01

A highly versatile, highly portable emergency communication system which permits deployment in a very short time to cover both wide areas and distant isolated areas depending upon mission requirements. The system employs a plurality of lightweight, fully self-contained repeaters which are deployed within the mission area to provide communication between field teams, and between each field team and a mobile communication control center. Each repeater contains a microcomputer controller, the program for which may be changed from the control center by the transmission of digital data within the audible range (300-3,000 Hz). Repeaters are accessed by portable/mobile transceivers, other repeaters, and the control center through the transmission and recognition of digital data code words in the subaudible range.

The distribution of interstellar dust in CALIFA edge-on galaxies via oligochromatic radiative transfer fitting

NASA Astrophysics Data System (ADS)

De Geyter, Gert; Baes, Maarten; Camps, Peter; Fritz, Jacopo; De Looze, Ilse; Hughes, Thomas M.; Viaene, Sébastien; Gentile, Gianfranco

2014-06-01

We investigate the amount and spatial distribution of interstellar dust in edge-on spiral galaxies, using detailed radiative transfer modelling of a homogeneous sample of 12 galaxies selected from the Calar Alto Legacy Integral Field Area survey. Our automated fitting routine, FITSKIRT, was first validated against artificial data. This is done by simultaneously reproducing the Sloan Digital Sky Survey g-, r-, i- and z-band observations of a toy model in order to combine the information present in the different bands. We show that this combined, oligochromatic fitting has clear advantages over standard monochromatic fitting especially regarding constraints on the dust properties. We model all galaxies in our sample using a three-component model, consisting of a double-exponential disc to describe the stellar and dust discs and using a Sérsic profile to describe the central bulge. The full model contains 19 free parameters, and we are able to constrain all these parameters to a satisfactory level of accuracy without human intervention or strong boundary conditions. Apart from two galaxies, the entire sample can be accurately reproduced by our model. We find that the dust disc is about 75 per cent more extended but only half as high as the stellar disc. The average face-on optical depth in the V band is 0.76 and the spread of 0.60 within our sample is quite substantial, which indicates that some spiral galaxies are relatively opaque even when seen face-on.

An automated and robust image processing algorithm for glaucoma diagnosis from fundus images using novel blood vessel tracking and bend point detection.

PubMed

M, Soorya; Issac, Ashish; Dutta, Malay Kishore

2018-02-01

Glaucoma is an ocular disease which can cause irreversible blindness. The disease is currently identified using specialized equipment operated by optometrists manually. The proposed work aims to provide an efficient imaging solution which can help in automating the process of Glaucoma diagnosis using computer vision techniques from digital fundus images. The proposed method segments the optic disc using a geometrical feature based strategic framework which improves the detection accuracy and makes the algorithm invariant to illumination and noise. Corner thresholding and point contour joining based novel methods are proposed to construct smooth contours of Optic Disc. Based on a clinical approach as used by ophthalmologist, the proposed algorithm tracks blood vessels inside the disc region and identifies the points at which first vessel bend from the optic disc boundary and connects them to obtain the contours of Optic Cup. The proposed method has been compared with the ground truth marked by the medical experts and the similarity parameters, used to determine the performance of the proposed method, have yield a high similarity of segmentation. The proposed method has achieved a macro-averaged f-score of 0.9485 and accuracy of 97.01% in correctly classifying fundus images. The proposed method is clinically significant and can be used for Glaucoma screening over a large population which will work in a real time. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of Mission Adaptive Digital Composite Aerostructure Technologies (MADCAT)

NASA Technical Reports Server (NTRS)

Cheung, Kenneth; Cellucci, Daniel; Copplestone, Grace; Cramer, Nick; Fusco, Jesse; Jenett, Benjamin; Kim, Joseph; Mazhari, Alex; Trinh, Greenfield; Swei, Sean

2017-01-01

This paper reviews the development of the Mission Adaptive Digital Composite Aerostructures Technologies (MADCAT) v0 demonstrator aircraft, utilizing a novel aerostructure concept that combines advanced composite materials manufacturing and fabrication technologies with a discrete construction approach to achieve high stiffness-to-density ratio ultra-light aerostructures that provide versatility and adaptability. This revolutionary aerostructure concept has the potential to change how future air vehicles are designed, built, and flown, with dramatic reductions in weight and manufacturing complexity the number of types of structural components needed to build air vehicles while enabling new mission objectives. We utilize the innovative digital composite materials and discrete construction technologies to demonstrate the feasibility of the proposed aerostructure concept, by building and testing a scaled prototype UAV, MADCAT v0. This paper presents an overview of the design and development of the MADCAT v0 flight demonstrator.

Two dimensional recursive digital filters for near real time image processing

NASA Technical Reports Server (NTRS)

Olson, D.; Sherrod, E.

1980-01-01

A program was designed toward the demonstration of the feasibility of using two dimensional recursive digital filters for subjective image processing applications that require rapid turn around. The concept of the use of a dedicated minicomputer for the processor for this application was demonstrated. The minicomputer used was the HP1000 series E with a RTE 2 disc operating system and 32K words of memory. A Grinnel 256 x 512 x 8 bit display system was used to display the images. Sample images were provided by NASA Goddard on a 800 BPI, 9 track tape. Four 512 x 512 images representing 4 spectral regions of the same scene were provided. These images were filtered with enhancement filters developed during this effort.

Physical Configuration of the Next Generation Home Network

NASA Astrophysics Data System (ADS)

Terada, Shohei; Kakishima, Yu; Hanawa, Dai; Oguchi, Kimio

The number of broadband users is rapidly increasing worldwide. Japan already has over 10 million FTTH users. Another trend is the rapid digitalization of home electrical equipment e. g. digital cameras and hard disc recorders. These trends will encourage the emergence of the next generation home network. In this paper, we introduce the next generation home network image and describe the five domains into which home devices can be classified. We then clarify the optimum medium with which to configure the network given the requirements imposed by the home environment. Wiring cable lengths for three network topologies are calculated. The results gained from the next generation home network implemented on the first phase testbed are shown. Finally, our conclusions are given.

A tailored 200 parameter VME based data acquisition system for IBA at the Lund Ion Beam Analysis Facility - Hardware and software

NASA Astrophysics Data System (ADS)

Elfman, Mikael; Ros, Linus; Kristiansson, Per; Nilsson, E. J. Charlotta; Pallon, Jan

2016-03-01

With the recent advances towards modern Ion Beam Analysis (IBA), going from one- or few-parameter detector systems to multi-parameter systems, it has been necessary to expand and replace the more than twenty years old CAMAC based system. A new VME multi-parameter (presently up to 200 channels) data acquisition and control system has been developed and implemented at the Lund Ion Beam Analysis Facility (LIBAF). The system is based on the VX-511 Single Board Computer (SBC), acting as master with arbiter functionality and consists of standard VME modules like Analog to Digital Converters (ADC's), Charge to Digital Converters (QDC's), Time to Digital Converters (TDC's), scaler's, IO-cards, high voltage and waveform units. The modules have been specially selected to support all of the present detector systems in the laboratory, with the option of future expansion. Typically, the detector systems consist of silicon strip detectors, silicon drift detectors and scintillator detectors, for detection of charged particles, X-rays and γ-rays. The data flow of the raw data buffers out from the VME bus to the final storage place on a 16 terabyte network attached storage disc (NAS-disc) is described. The acquisition process, remotely controlled over one of the SBCs ethernet channels, is also discussed. The user interface is written in the Kmax software package, and is used to control the acquisition process as well as for advanced online and offline data analysis through a user-friendly graphical user interface (GUI). In this work the system implementation, layout and performance are presented. The user interface and possibilities for advanced offline analysis are also discussed and illustrated.

Archive of digital boomer seismic reflection data collected during USGS cruises 94GFP01, 95GFP01, 96GFP01, 97GFP01, and 98GFP02 in Lakes Pontchartrain, Borgne, and Maurepas, Louisiana, 1994-1998

USGS Publications Warehouse

Calderon, Karynna; Dadisman, Shawn V.; Kindinger, Jack G.; Williams, S. Jeffress; Flocks, James G.; Penland, Shea; Wiese, Dana S.

2003-01-01

The U.S. Geological Survey, in cooperation with the University of New Orleans, the Lake Pontchartrain Basin Foundation, the National Oceanic and Atmospheric Administration, the Coalition to Restore Coastal Louisiana, the U.S. Army Corps of Engineers, the Environmental Protection Agency, and the University of Georgia, conducted five geophysical surveys of Lakes Pontchartrain, Borgne, and Maurepas in Louisiana from 1994 to 1998. This report serves as an archive of unprocessed digital boomer seismic reflection data, trackline maps, navigation files, observers' logbooks, GIS information, and formal FGDC metadata. In addition, a filtered and gained digital GIF image of each seismic profile is provided. Refer to the Acronyms page for expansion of acronyms and abbreviations used in this report. The archived trace data are in standard Society of Exploration Geophysicists (SEG) SEG-Y format (Barry and others, 1975) and may be downloaded and processed with commercial or public domain software such as Seismic Unix (SU). Examples of SU processing scripts and in-house (USGS) software for viewing SEG-Y headers (Zihlman, 1992) are also provided. Processed profile images, trackline maps, navigation files, and formal metadata may be viewed with a web browser, and scanned handwritten logbooks may be viewed with Adobe Reader. To access the information contained on these discs, open the file 'index.htm' located at the top level of the discs using a web browser. This report also contains hyperlinks to USGS collaborators and other agencies. These links are only accessible if access to the Internet is available while viewing these documents.

Digital fabrication of multi-material biomedical objects.

PubMed

Cheung, H H; Choi, S H

2009-12-01

This paper describes a multi-material virtual prototyping (MMVP) system for modelling and digital fabrication of discrete and functionally graded multi-material objects for biomedical applications. The MMVP system consists of a DMMVP module, an FGMVP module and a virtual reality (VR) simulation module. The DMMVP module is used to model discrete multi-material (DMM) objects, while the FGMVP module is for functionally graded multi-material (FGM) objects. The VR simulation module integrates these two modules to perform digital fabrication of multi-material objects, which can be subsequently visualized and analysed in a virtual environment to optimize MMLM processes for fabrication of product prototypes. Using the MMVP system, two biomedical objects, including a DMM human spine and an FGM intervertebral disc spacer are modelled and digitally fabricated for visualization and analysis in a VR environment. These studies show that the MMVP system is a practical tool for modelling, visualization, and subsequent fabrication of biomedical objects of discrete and functionally graded multi-materials for biomedical applications. The system may be adapted to control MMLM machines with appropriate hardware for physical fabrication of biomedical objects.

An automated digital data collection and analysis system for the Charpy Impact Tester

NASA Technical Reports Server (NTRS)

Kohne, Glenn S.; Spiegel, F. Xavier

1994-01-01

The standard Charpy Impact Tester has been modified by the addition of a system of hardware and software to improve the accuracy and consistency of measurements made during specimen fracturing experiments. An optical disc, light source, and detector generate signals that indicate the pendulum position as a function of time. These signals are used by a computer to calculate the velocity and kinetic energy of the pendulum as a function of its position.

The Bulletin of Military Operations Research, PHALANX, Vol. 31, No. 2.

DTIC Science & Technology

1998-06-01

introduction of the Pentium II processor, the writeable CD, and the Digital Video Disc (DVD). Just around the corner, around the turn of the century...broader audi- ence. Presentations that use special visual aids ( videos , computers, etc.), short presen- tations best depicted with color charts...Throughout the treatment of data, anoth- er weapon we should take is Tukey’s Tor- pedo (John W. Tukey, "Sunset Salvo," The American Statistician, vol

Photographic Video Disc Technology Assessment

DTIC Science & Technology

1976-09-27

by a universal type motor that is driven from the ac power lines using a triac . The triac is controlled by a phase locked loop control circuit that...Regardless of signal format, direct analogue or an A/D converted digital signal, it is recorded by modulated laser beam and can be read out by either...was made to record with frequency modulation (FM) because of its immunity to noise at low frequencies where much of the system noise is. The usual

Morphogenic designer--an efficient tool to digitally design tooth forms.

PubMed

Hajtó, J; Marinescu, C; Silva, N R F A

2014-01-01

Different digital software tools are available today for the purpose of designing anatomically correct anterior and posterior restorations. The current concepts present weaknesses, which can be potentially addressed by more advanced modeling tools, such as the ones already available in professional CAD (Computer Aided Design) graphical software. This study describes the morphogenic designer (MGD) as an efficient and easy method for digitally designing tooth forms for the anterior and posterior dentition. Anterior and posterior tooth forms were selected from a collection of digitalized natural teeth and subjectively assessed as "average". The models in the form of STL files were filtered, cleaned, idealized, and re-meshed to match the specifications of the software used. The shapes were then imported as wavefront ".obj" model into Modo 701, software built for modeling, texturing, visualization, and animation. In order to create a parametric design system, intentional interactive deformations were performed on the average tooth shapes and then further defined as morph targets. By combining various such parameters, several tooth shapes were formed virtually and their images presented. MGD proved to be a versatile and powerful tool for the purpose of esthetic and functional digital crown designs.

Method of implementing digital phase-locked loops

NASA Technical Reports Server (NTRS)

Stephens, Scott A. (Inventor); Thomas, Jess Brooks, Jr. (Inventor)

1993-01-01

In a new formulation for digital phase-locked loops, loop-filter constants are determined from loop roots that can each be selectively placed in the s-plane on the basis of a new set of parameters, each with simple and direct physical meaning in terms of loop noise bandwidth, root-specific decay rate, or root-specific damping. Loops of first to fourth order are treated in the continuous-update approximation (BLT yields 0) and in a discrete-update formulation with arbitrary BLT. Deficiencies of the continuous-update approximation in large-BLT applications are avoided in the new discrete-update formulation. A new method for direct, transient-free acquisition with third- and fourth-order loops can improve the versatility and reliability of acquisition with such loops.

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

Li, Na; Wu, Yu-Ping; Min, Hao

A radio-frequency (RF) source designed for cold atom experiments is presented. The source uses AD9858, a direct digital synthesizer, to generate the sine wave directly, up to 400 MHz, with sub-Hz resolution. An amplitude control circuit consisting of wideband variable gain amplifier and high speed digital to analog converter is integrated into the source, capable of 70 dB off isolation and 4 ns on-off keying. A field programmable gate array is used to implement a versatile frequency and amplitude co-sweep logic. Owing to modular design, the RF sources have been used on many cold atom experiments to generate various complicatedmore » RF sequences, enriching the operation schemes of cold atoms, which cannot be done by standard RF source instruments.« less

Large Format Multifunction 2-Terabyte Optical Disk Storage System

NASA Technical Reports Server (NTRS)

Kaiser, David R.; Brucker, Charles F.; Gage, Edward C.; Hatwar, T. K.; Simmons, George O.

1996-01-01

The Kodak Digital Science OD System 2000E automated disk library (ADL) base module and write-once drive are being developed as the next generation commercial product to the currently available System 2000 ADL. Under government sponsorship with the Air Force's Rome Laboratory, Kodak is developing magneto-optic (M-O) subsystems compatible with the Kodak Digital Science ODW25 drive architecture, which will result in a multifunction (MF) drive capable of reading and writing 25 gigabyte (GB) WORM media and 15 GB erasable media. In an OD system 2000 E ADL configuration with 4 MF drives and 100 total disks with a 50% ration of WORM and M-O media, 2.0 terabytes (TB) of versatile near line mass storage is available.

Learning and optimization with cascaded VLSI neural network building-block chips

NASA Technical Reports Server (NTRS)

Duong, T.; Eberhardt, S. P.; Tran, M.; Daud, T.; Thakoor, A. P.

1992-01-01

To demonstrate the versatility of the building-block approach, two neural network applications were implemented on cascaded analog VLSI chips. Weights were implemented using 7-b multiplying digital-to-analog converter (MDAC) synapse circuits, with 31 x 32 and 32 x 32 synapses per chip. A novel learning algorithm compatible with analog VLSI was applied to the two-input parity problem. The algorithm combines dynamically evolving architecture with limited gradient-descent backpropagation for efficient and versatile supervised learning. To implement the learning algorithm in hardware, synapse circuits were paralleled for additional quantization levels. The hardware-in-the-loop learning system allocated 2-5 hidden neurons for parity problems. Also, a 7 x 7 assignment problem was mapped onto a cascaded 64-neuron fully connected feedback network. In 100 randomly selected problems, the network found optimal or good solutions in most cases, with settling times in the range of 7-100 microseconds.

Polishing performance of multiple-use silicone rubber-based polishing instruments with and without disinfection/sterilization.

PubMed

Heintze, Siegward Dietmar; Forjanic, Monika

2008-10-01

To evaluate the effect of the multiple-use of a three-step rubber-based polishing system on the polishing performance with and without a disinfection/sterilization protocol with prolonged disinfection (overnight). The three-step polishing system Astropol was applied under standardized contact pressure of 2 N on 320 grit pre-roughened flat composite specimens of Tetric EvoCeram for 10 seconds (F and P disc) and 30 seconds (HP disc) respectively. After each polishing step, the surface gloss and roughness were measured with a glossmeter and an optical sensor (FRT MicroProf), respectively. Material loss of the composite specimens and polishing instruments were measured after each step with a high precision digital scale. For all four variables (surface gloss, surface roughness, composite loss, loss of rubber material) the mean percentage of change compared to the reference was calculated. Already after the first use, the instruments which were used without disinfection or sterilization demonstrated a statistically significantly reduced polishing performance in all polishing steps compared to the reference (new polishing system) (t-test, P < 0.05). In addition, this loss in performance further increased with the second and third re-use. Especially the third component (Astropol HP) was affected by performance loss. By contrast, the multiple-use of the instruments which were subjected to prolonged disinfection did not result in a reduced polishing performance. For the P disc, a statistically significant improvement of the polishing performance could be observed throughout almost all multiple-use sessions (ANOVA, P < 0.05). The improved polishing performance was, however, accompanied by an increased loss of the silicone rubber material of the P and F polishing discs; the HP discs were not affected by this loss. Furthermore, particles of the rubber material also adhered to the composite. The polishing performance of the discs which were only subjected to the sterilization process was not statistically significantly different to the polishing performance of the control group in terms of surface roughness; but the surface gloss was worse than that of the control group. No loss of rubber material or adherence to the composite was observed in this group.

Low cost 3D scanning process using digital image processing

NASA Astrophysics Data System (ADS)

Aguilar, David; Romero, Carlos; Martínez, Fernando

2017-02-01

This paper shows the design and building of a low cost 3D scanner, able to digitize solid objects through contactless data acquisition, using active object reflection. 3D scanners are used in different applications such as: science, engineering, entertainment, etc; these are classified in: contact scanners and contactless ones, where the last ones are often the most used but they are expensive. This low-cost prototype is done through a vertical scanning of the object using a fixed camera and a mobile horizontal laser light, which is deformed depending on the 3-dimensional surface of the solid. Using digital image processing an analysis of the deformation detected by the camera was done; it allows determining the 3D coordinates using triangulation. The obtained information is processed by a Matlab script, which gives to the user a point cloud corresponding to each horizontal scanning done. The obtained results show an acceptable quality and significant details of digitalized objects, making this prototype (built on LEGO Mindstorms NXT kit) a versatile and cheap tool, which can be used for many applications, mainly by engineering students.

Method and system for providing precise multi-function modulation

NASA Technical Reports Server (NTRS)

Davarian, Faramaz (Inventor); Sumida, Joe T. (Inventor)

1989-01-01

A method and system is disclosed which provides precise multi-function digitally implementable modulation for a communication system. The invention provides a modulation signal for a communication system in response to an input signal from a data source. A digitized time response is generated from samples of a time domain representation of a spectrum profile of a selected modulation scheme. The invention generates and stores coefficients for each input symbol in accordance with the selected modulation scheme. The output signal is provided by a plurality of samples, each sample being generated by summing the products of a predetermined number of the coefficients and a predetermined number of the samples of the digitized time response. In a specific illustrative implementation, the samples of the output signals are converted to analog signals, filtered and used to modulate a carrier in a conventional manner. The invention is versatile in that it allows for the storage of the digitized time responses and corresponding coefficient lookup table of a number of modulation schemes, any of which may then be selected for use in accordance with the teachings of the invention.

Selected papers in the applied computer sciences 1992

USGS Publications Warehouse

Wiltshire, Denise A.

1992-01-01

This compilation of short papers reports on technical advances in the applied computer sciences. The papers describe computer applications in support of earth science investigations and research. This is the third volume in the series "Selected Papers in the Applied Computer Sciences." Listed below are the topics addressed in the compilation:Integration of geographic information systems and expert systems for resource management,Visualization of topography using digital image processing,Development of a ground-water data base for the southeastern Uited States using a geographic information system,Integration and aggregation of stream-drainage data using a geographic information system,Procedures used in production of digital geologic coverage using compact disc read-only memory (CD-ROM) technology, andAutomated methods for producing a technical publication on estimated water use in the United States.

Proceedings of the International Conference on Stiff Computation, April 12-14, 1982, Park City, Utah. Volume I.

DTIC Science & Technology

1982-01-01

physical reasoning and based on computational experience with similar equations. There is another non- automatic way: through proper scaling of all...1979) for an automatic scheme for this scaling on a digitial computer . Shampine(1980) reports a special definition of stiffness appropriate for...an analog for a laboratory that typically already has a digital computer . The digitial is much more versatile. Also there does not yet exist " software

VEGAS: VErsatile GBT Astronomical Spectrometer

NASA Astrophysics Data System (ADS)

Bussa, Srikanth; VEGAS Development Team

2012-01-01

The National Science Foundation Advanced Technologies and Instrumentation (NSF-ATI) program is funding a new spectrometer backend for the Green Bank Telescope (GBT). This spectrometer is being built by the CICADA collaboration - collaboration between the National Radio Astronomy Observatory (NRAO) and the Center for Astronomy Signal Processing and Electronics Research (CASPER) at the University of California Berkeley.The backend is named as VErsatile GBT Astronomical Spectrometer (VEGAS) and will replace the capabilities of the existing spectrometers. This backend supports data processing from focal plane array systems. The spectrometer will be capable of processing up to 1.25 GHz bandwidth from 8 dual polarized beams or a bandwidth up to 10 GHz from a dual polarized beam.The spectrometer will be using 8-bit analog to digital converters (ADC), which gives a better dynamic range than existing GBT spectrometers. There will be 8 tunable digital sub-bands within the 1.25 GHz bandwidth, which will enhance the capability of simultaneous observation of multiple spectral transitions. The maximum spectral dump rate to disk will be about 0.5 msec. The vastly enhanced backend capabilities will support several science projects with the GBT. The projects include mapping temperature and density structure of molecular clouds; searches for organic molecules in the interstellar medium; determination of the fundamental constants of our evolving Universe; red-shifted spectral features from galaxies across cosmic time and survey for pulsars in the extreme gravitational environment of the Galactic Center.

Versatile single-chip event sequencer for atomic physics experiments

NASA Astrophysics Data System (ADS)

Eyler, Edward

2010-03-01

A very inexpensive dsPIC microcontroller with internal 32-bit counters is used to produce a flexible timing signal generator with up to 16 TTL-compatible digital outputs, with a time resolution and accuracy of 50 ns. This time resolution is easily sufficient for event sequencing in typical experiments involving cold atoms or laser spectroscopy. This single-chip device is capable of triggered operation and can also function as a sweeping delay generator. With one additional chip it can also concurrently produce accurately timed analog ramps, and another one-chip addition allows real-time control from an external computer. Compared to an FPGA-based digital pattern generator, this design is slower but simpler and more flexible, and it can be reprogrammed using ordinary `C' code without special knowledge. I will also describe the use of the same microcontroller with additional hardware to implement a digital lock-in amplifier and PID controller for laser locking, including a simple graphics-based control unit. This work is supported in part by the NSF.

A 0.18 micrometer CMOS Thermopile Readout ASIC Immune to 50 MRAD Total Ionizing Dose (SI) and Single Event Latchup to 174MeV-cm(exp 2)/mg

NASA Technical Reports Server (NTRS)

Quilligan, Gerard T.; Aslam, Shahid; Lakew, Brook; DuMonthier, Jeffery J.; Katz, Richard B.; Kleyner, Igor

2014-01-01

Radiation hardened by design (RHBD) techniques allow commercial CMOS circuits to operate in high total ionizing dose and particle fluence environments. Our radiation hard multi-channel digitizer (MCD) ASIC (Figure 1) is a versatile analog system on a chip (SoC) fabricated in 180nm CMOS. It provides 18 chopper stabilized amplifier channels, a 16- bit sigma-delta analog-digital converter (SDADC) and an on-chip controller. The MCD was evaluated at Goddard Space Flight Center and Texas A&M University's radiation effects facilities and found to be immune to single event latchup (SEL) and total ionizing dose (TID) at 174 MeV-cm(exp 2)/mg and 50 Mrad (Si) respectively.

Programmable controlled mode-locked fiber laser using a digital micromirror device.

PubMed

Liu, Wu; Fan, Jintao; Xie, Chen; Song, Youjian; Gu, Chenlin; Chai, Lu; Wang, Chingyue; Hu, Minglie

2017-05-15

A digital micromirror device (DMD)-based arbitrary spectrum amplitude shaper is incorporated into a large-mode-area photonic crystal fiber laser cavity. The shaper acts as an in-cavity programmable filter and provides large tunable dispersion from normal to anomalous. As a result, mode-locking is achieved in different dispersion regimes with watt-level high output power. By programming different filter profiles on the DMD, the laser generates femtosecond pulse with a tunable central wavelength and controllable bandwidth. Under conditions of suitable cavity dispersion and pump power, design-shaped spectra are directly obtained by varying the amplitude transfer function of the filter. The results show the versatility of the DMD-based in-cavity filter for flexible control of the pulse dynamics in a mode-locked fiber laser.

Digital coincidence counting

NASA Astrophysics Data System (ADS)

Buckman, S. M.; Ius, D.

1996-02-01

This paper reports on the development of a digital coincidence-counting system which comprises a custom-built data acquisition card and associated PC software. The system has been designed to digitise the pulse-trains from two radiation detectors at a rate of 20 MSamples/s with 12-bit resolution. Through hardware compression of the data, the system can continuously record both individual pulse-shapes and the time intervals between pulses. Software-based circuits are used to process the stored pulse trains. These circuits are constructed simply by linking together icons representing various components such as coincidence mixers, time delays, single-channel analysers, deadtimes and scalers. This system enables a pair of pulse trains to be processed repeatedly using any number of different methods. Some preliminary results are presented in order to demonstrate the versatility and efficiency of this new method.

Shuttle bit rate synchronizer. [signal to noise ratios and error analysis

NASA Technical Reports Server (NTRS)

Huey, D. C.; Fultz, G. L.

1974-01-01

A shuttle bit rate synchronizer brassboard unit was designed, fabricated, and tested, which meets or exceeds the contractual specifications. The bit rate synchronizer operates at signal-to-noise ratios (in a bit rate bandwidth) down to -5 dB while exhibiting less than 0.6 dB bit error rate degradation. The mean acquisition time was measured to be less than 2 seconds. The synchronizer is designed around a digital data transition tracking loop whose phase and data detectors are integrate-and-dump filters matched to the Manchester encoded bits specified. It meets the reliability (no adjustments or tweaking) and versatility (multiple bit rates) of the shuttle S-band communication system through an implementation which is all digital after the initial stage of analog AGC and A/D conversion.

Effect of engraving speeds of CO₂ laser irradiation on In-Ceram Alumina roughness: a pilot study.

PubMed

Ersu, Bahadır; Ersoy, Orkun; Yuzugullu, Bulem; Canay, Senay

2015-05-01

The aim of the study was to determine the effect of CO₂ laser on surface roughness of In-Ceram-Alumina-ceramic. Four aluminum-oxide ceramic disc specimens were prepared of In-Ceram Alumina. Discs received CO₂ laser irradiation with different engraving speeds (100, 400, 600 and 800 mm/min) as a surface treatment. The roughness of the surfaces was measured on digital elevation models reconstructed from stereoscopic images acquired by scanning-electron-microscope. Surface roughness data were analyzed with One-Way-Analysis-of-Variance at a significance level of p<0.05. There was no significant difference between the roughness values (p=0.82). Due to higher laser durations, partial melting signs were observed on the surfaces. Tearing, smearing and swelling occurred on melted surfaces. Swelling accompanying melting increased the surface roughness, while laser power was fixed and different laser engraving speeds were applied. Although different laser irradiation speeds did not affect the roughness of ceramic surfaces, swelling was observed which led to changes on surfaces.

The Tully-Fisher relation for 25 000 Sloan Digital Sky Survey galaxies as a function of environment

NASA Astrophysics Data System (ADS)

Mocz, P.; Green, A.; Malacari, M.; Glazebrook, K.

2012-09-01

We construct Tully-Fisher relationships (TFRs) in the u, g, r, i and z bands and stellar mass TFRs for a sample of 25 698 late spiral-type galaxies (with 0.045 < z < 0.085) from the Sloan Digital Sky Survey (SDSS) and study the effects of environment on the relation. We use SDSS-measured Balmer emission line widths, vFWHM, as a proxy for disc circular velocity, vcirc. A priori, it is not clear whether we can construct accurate TFRs given the small 3 arcsec diameter of the fibres used for SDSS spectroscopic measurements. However, we show by modelling the Hα emission profile as observed through a 3 arcsec aperture that for galaxies at appropriate redshifts (z > 0.045) the fibres sample enough of the disc to obtain a linear relationship between vFWHM and vcirc, allowing us to obtain a TFR and to investigate dependence on other variables. We also develop a methodology for distinguishing between astrophysical and sample bias in the fibre TFR trends. We observe the well-known steepening of the TFR in redder bands in our sample. We divide the sample of galaxies into four equal groups using projected neighbour density (Σ) quartiles and find no significant dependence on environment, extending previous work to a wider range of environments and a much larger sample. Having demonstrated that we can construct SDSS-based TFRs is very useful for future TFR studies because of the large sample size available in the SDSS.

Validation of a digital mammographic unit model for an objective and highly automated clinical image quality assessment.

PubMed

Perez-Ponce, Hector; Daul, Christian; Wolf, Didier; Noel, Alain

2013-08-01

In mammography, image quality assessment has to be directly related to breast cancer indicator (e.g. microcalcifications) detectability. Recently, we proposed an X-ray source/digital detector (XRS/DD) model leading to such an assessment. This model simulates very realistic contrast-detail phantom (CDMAM) images leading to gold disc (representing microcalcifications) detectability thresholds that are very close to those of real images taken under the simulated acquisition conditions. The detection step was performed with a mathematical observer. The aim of this contribution is to include human observers into the disc detection process in real and virtual images to validate the simulation framework based on the XRS/DD model. Mathematical criteria (contrast-detail curves, image quality factor, etc.) are used to assess and to compare, from the statistical point of view, the cancer indicator detectability in real and virtual images. The quantitative results given in this paper show that the images simulated by the XRS/DD model are useful for image quality assessment in the case of all studied exposure conditions using either human or automated scoring. Also, this paper confirms that with the XRS/DD model the image quality assessment can be automated and the whole time of the procedure can be drastically reduced. Compared to standard quality assessment methods, the number of images to be acquired is divided by a factor of eight. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

Binary/Analog CCD Correlator Development.

DTIC Science & Technology

1981-07-01

architecture , design and performance of a general purpose, 1,024-stage, programmable transversal filter implemented in CCD/NMOS technology is described. The device features programmability of the reference signal, the filter length and weighting coefficient resolution. Off-ship circuitry is minimized by incorporating both analog and digital support circuitry, on-chip. This results in a monolithic analog signal processing system that has the flexibility to be operated in nine programmable configurations, from 1,024-stages by 1-bit, to 128-stages by 8-bits. The versatility

Giovanni: A System for Rapid Access, Visualization and Analysis of Earth Science Data Online

NASA Technical Reports Server (NTRS)

Shen, S.; Rui, H.; Liu, Z.; Zhu, T.; Lu, L.; Berrick, S.; Leptoukh, G.; Teng, W.; Acker, J.; Johnson, J.

2005-01-01

Collecting data and understanding data structures traditionally are the first steps that a user must take, before the core investigation can begin. This is a time-consuming and challenging task, especially when science objectives require users to deal with large multi-sensor data that are usually in different formats and internal structures. The Goddard Earth Sciences Data and Information Services Center (GES DISC) has created the GES DISC Interactive Online Visualization and ANalysis Infrastructure, Giovanni, to enable Web-based visualization and analysis of satellite remotely sensed meteorological, oceanographic, and hydrologic data sets, without users having to download data. The current operational Giovanni interfaces provide the capability to process a number of important satellite measurements, such as (1) ozone and other trace gases from TOMS, OMI, HALOE, and MLS; (2) air temperature, water vapor, and geopotential height from AIRS; (3) aerosols from MODIS TerrdAqua, and GOCART model; (4) precipitation from TRMM and ground measurements; (5) chlorophyll and other ocean color products from SeaWiFS and MODIS Aqua; and (6) sea surface temperature from MODIS Aqua. Depending on the input data structure, the system provides simple statistical analysis and creates time-averaged area plot, area-averaged time series, animations, Hovmoller latitude vs. time and longitude vs. time plots, as well as vertical profiles. The inter-comparison interfaces allow a user to compare observations from different instruments, to conduct anomaly analysis, and to study basic relationships between physical parameters. Giovanni handles data with different temporal and spatial resolutions and, thus, enables both regional and global long-term climate research and short-term special events investigation, as well as data validations and assessments. Because of its simplicity of usage, Giovanni is powerful and versatile, able to assist a wide range of users, from the discipline scientists conducting preliminary research in various fields, to students in the classroom learning about weather, climate, and other natural phenomena. Giovanni can be accessed from: http://disc. esfc.nasa.gov/techlab/giovanni/index.shtml

A label-free nanostructured plasmonic biosensor based on Blu-ray discs with integrated microfluidics for sensitive biodetection.

PubMed

López-Muñoz, Gerardo A; Estevez, M-Carmen; Peláez-Gutierrez, E Cristina; Homs-Corbera, Antoni; García-Hernandez, M Carmen; Imbaud, J Ignacio; Lechuga, Laura M

2017-10-15

Nanostructure-based plasmonic biosensors have quickly positioned themselves as interesting candidates for the design of portable optical biosensor platforms considering the potential benefits they can offer in integration, miniaturization, multiplexing, and real-time label-free detection. We have developed a simple integrated nanoplasmonic sensor taking advantage of the periodic nanostructured array of commercial Blu-ray discs. Sensors with two gold film thicknesses (50 and 100nm) were fabricated and optically characterized by varying the oblique-angle of the incident light in optical reflectance measurements. Contrary to the use normal light incidence previously reported with other optical discs, we observed an enhancement in sensitivity and a narrowing of the resonant linewidths as the light incidence angle was increased, which could be related to the generation of Fano resonant modes. The new sensors achieve a figure of merit (FOM) up to 35 RIU -1 and a competitive bulk limit of detection (LOD) of 6.3×10 -6 RIU. These values significantly improve previously reported results obtained with normal light incidence reflectance measurements using similar structures. The sensor has been combined with versatile, simple, ease to-fabricate microfluidics. The integrated chip is only 1cm 2 (including a PDMS flow cell with a 50µm height microfluidic channel fabricated with double-sided adhesive tape) and all the optical components are mounted on a 10cm×10cm portable prototype, illustrating its facile miniaturization, integration and potential portability. Finally, to assess the label-free biosensing capability of the new sensor, we have evaluated the presence of specific antibodies against the GTF2b protein, a tumor-associate antigen (TAA) related to colorectal cancer. We have achieved a LOD in the pM order and have assessed the feasibility of directly measuring biological samples such as human serum. Copyright © 2017 Elsevier B.V. All rights reserved.

Two Body Wear of Newly Introduced Nanocomposite Teeth and Cross Linked Four Layered Acrylic Teeth: a Comparitive In Vitro Study.

PubMed

Ilangkumaran, R; Srinivasan, J; Baburajan, K; Balaji, N

2014-12-01

Wear of complete denture teeth results in compromise in denture esthetics and functions. To counteract this problem, artificial teeth with increased wear resistance had been introduced in the market such as nanocomposite teeth. The purpose of this study was to compare the amount of wear between nanocomposite teeth and acrylic teeth. Fifteen specimens were chosen from each group namely the nanocomposite teeth (SR_-PHONARES) and the acrylic teeth (ACRY PLUS). Maxillary premolar was only chosen for testing and the samples were customized according to the specifications of the pin on disc machine. Pin on disc machine is a two body tribometer which quantifies the amount of wear under a specific load and time. Test samples were mounted on to the receptacle of the pin on disc machine and tested under a load of 0.3 kg for 1,000 cycles of rotation against a 600 grit emery paper. The amount of wear is displayed from the digital reading obtained from the pin on disc machine. After statistical analysis, it was found that, the amount of wear is more in four layered acrylic teeth. The p value obtained is 0.002 (<0.005) thus implies that the difference in wear between nanocomposite teeth and acrylic teeth is statistically significant. Though the nanocomposite teeth has less amount of wear than the four layered acrylic teeth, the difference is very less and adds only to a little clinical significance but the cost of the nanocomposite is four times that of the acrylic teeth. Further clinical studies must be performed to confirm our results.

Reviews

NASA Astrophysics Data System (ADS)

2005-05-01

WE RECOMMEND Private Universe and Minds of Our Own This DVD for teachers addresses challenges faced in the classroom. EasySenseLink and EasySense Flash Logger These two dataloggers are fast, versatile and inexpensive. The Butthead Game, Space Rifle and Disc Shooter Together, these toys can be used to explain the photoelectric effect. Resistance and thickness boards These high-quality, value-for-money boards produce excellent results. WORTH A LOOK Einstein A to Z A useful and well researched text about EinsteinÂ's life and work. Einstein Alive Depending on how it is lit, this display can look concave or convex. Phyzzing Through Physics As PowerPoint presentations go, this one is useful and good value. HANDLE WITH CARE Pressure toadstools An overpriced tool that you could make yourself using dowelling. Parallel and series boards Easily damaged, these boards are best used in demonstrations only. WEB WATCH Educational websites that make electricity fun to learn. Applets website: an online gem for teachers.

3D-Printed Graphene/Polylactic Acid Electrodes Promise High Sensitivity in Electroanalysis.

PubMed

Manzanares Palenzuela, C Lorena; Novotný, Filip; Krupička, Petr; Sofer, Zdeněk; Pumera, Martin

2018-05-01

Additive manufacturing provides a unique tool for prototyping structures toward electrochemical sensing, due to its ability to produce highly versatile, tailored-shaped devices in a low-cost and fast way with minimized waste. Here we present 3D-printed graphene electrodes for electrochemical sensing. Ring- and disc-shaped electrodes were 3D-printed with a Fused Deposition Modeling printer and characterized using cyclic voltammetry and scanning electron microscopy. Different redox probes K 3 Fe(CN) 6 :K 4 Fe(CN) 6 , FeCl 3 , ascorbic acid, Ru(NH 3 ) 6 Cl 3 , and ferrocene monocarboxylic acid) were used to assess the electrochemical performance of these devices. Finally, the electrochemical detection of picric acid and ascorbic acid was carried out as proof-of-concept analytes for sensing applications. Such customizable platforms represent promising alternatives to conventional electrodes for a wide range of sensing applications.

UmUTracker: A versatile MATLAB program for automated particle tracking of 2D light microscopy or 3D digital holography data

NASA Astrophysics Data System (ADS)

Zhang, Hanqing; Stangner, Tim; Wiklund, Krister; Rodriguez, Alvaro; Andersson, Magnus

2017-10-01

We present a versatile and fast MATLAB program (UmUTracker) that automatically detects and tracks particles by analyzing video sequences acquired by either light microscopy or digital in-line holographic microscopy. Our program detects the 2D lateral positions of particles with an algorithm based on the isosceles triangle transform, and reconstructs their 3D axial positions by a fast implementation of the Rayleigh-Sommerfeld model using a radial intensity profile. To validate the accuracy and performance of our program, we first track the 2D position of polystyrene particles using bright field and digital holographic microscopy. Second, we determine the 3D particle position by analyzing synthetic and experimentally acquired holograms. Finally, to highlight the full program features, we profile the microfluidic flow in a 100 μm high flow chamber. This result agrees with computational fluid dynamic simulations. On a regular desktop computer UmUTracker can detect, analyze, and track multiple particles at 5 frames per second for a template size of 201 ×201 in a 1024 × 1024 image. To enhance usability and to make it easy to implement new functions we used object-oriented programming. UmUTracker is suitable for studies related to: particle dynamics, cell localization, colloids and microfluidic flow measurement. Program Files doi : http://dx.doi.org/10.17632/fkprs4s6xp.1 Licensing provisions : Creative Commons by 4.0 (CC by 4.0) Programming language : MATLAB Nature of problem: 3D multi-particle tracking is a common technique in physics, chemistry and biology. However, in terms of accuracy, reliable particle tracking is a challenging task since results depend on sample illumination, particle overlap, motion blur and noise from recording sensors. Additionally, the computational performance is also an issue if, for example, a computationally expensive process is executed, such as axial particle position reconstruction from digital holographic microscopy data. Versatile robust tracking programs handling these concerns and providing a powerful post-processing option are significantly limited. Solution method: UmUTracker is a multi-functional tool to extract particle positions from long video sequences acquired with either light microscopy or digital holographic microscopy. The program provides an easy-to-use graphical user interface (GUI) for both tracking and post-processing that does not require any programming skills to analyze data from particle tracking experiments. UmUTracker first conduct automatic 2D particle detection even under noisy conditions using a novel circle detector based on the isosceles triangle sampling technique with a multi-scale strategy. To reduce the computational load for 3D tracking, it uses an efficient implementation of the Rayleigh-Sommerfeld light propagation model. To analyze and visualize the data, an efficient data analysis step, which can for example show 4D flow visualization using 3D trajectories, is included. Additionally, UmUTracker is easy to modify with user-customized modules due to the object-oriented programming style Additional comments: Program obtainable from https://sourceforge.net/projects/umutracker/

The Digital Planetarium: A New Frontier of Public Outreach

NASA Astrophysics Data System (ADS)

Buick, David; Pailevanian, T.; Harootonian, S.; Garibyan, A.; Krestow, J.

2013-01-01

Inspiring youth to pursue the STEM fields is a vital aspect of modern society. Not only does a digital planetarium provide the catalyst to spark the minds of children, but to an assortment of age groups, in a variety of mediums. A digital planetarium is a versatile theatrical environment that can be used for a variety of purposes. The digital planetarium at Glendale Community College is the shining star of the campus. Its ability to satisfy the needs of multiple departments such as, the physical sciences, the biological sciences, the arts, and the foreign languages has become the sharpest tool for public outreach. In this poster we will be discussing the several uses of Glendale Community College’s digital planetarium as well as the programs used to implement them. The central functions of the digital planetarium includes: educational shows, college classes, and entertainment. Educational shows consist of visiting grade school groups, as well as afternoon shows about a specific astronomical topics, which are open to the public. The planetarium is also used to allow Glendale Community College students to see a visual representation of the current curriculum covered in their courses, such as astronomy, organic chemistry, and geology. The true ingenuity and flexibility of the planetarium is the software. Digital Sky allows for the projection of rendered of movies, 3D modeling and student art in the appropriate formats, onto the dome. The digital planetarium is a wonderful tool used to assist, reach out to and display the majesty and complexity of the sciences in an innovative and dynamic method.

Instrument for Real-Time Digital Nucleic Acid Amplification on Custom Microfluidic Devices

PubMed Central

Selck, David A.

2016-01-01

Nucleic acid amplification tests that are coupled with a digital readout enable the absolute quantification of single molecules, even at ultralow concentrations. Digital methods are robust, versatile and compatible with many amplification chemistries including isothermal amplification, making them particularly invaluable to assays that require sensitive detection, such as the quantification of viral load in occult infections or detection of sparse amounts of DNA from forensic samples. A number of microfluidic platforms are being developed for carrying out digital amplification. However, the mechanistic investigation and optimization of digital assays has been limited by the lack of real-time kinetic information about which factors affect the digital efficiency and analytical sensitivity of a reaction. Commercially available instruments that are capable of tracking digital reactions in real-time are restricted to only a small number of device types and sample-preparation strategies. Thus, most researchers who wish to develop, study, or optimize digital assays rely on the rate of the amplification reaction when performed in a bulk experiment, which is now recognized as an unreliable predictor of digital efficiency. To expand our ability to study how digital reactions proceed in real-time and enable us to optimize both the digital efficiency and analytical sensitivity of digital assays, we built a custom large-format digital real-time amplification instrument that can accommodate a wide variety of devices, amplification chemistries and sample-handling conditions. Herein, we validate this instrument, we provide detailed schematics that will enable others to build their own custom instruments, and we include a complete custom software suite to collect and analyze the data retrieved from the instrument. We believe assay optimizations enabled by this instrument will improve the current limits of nucleic acid detection and quantification, improving our fundamental understanding of single-molecule reactions and providing advancements in practical applications such as medical diagnostics, forensics and environmental sampling. PMID:27760148

Analysis of ERTS imagery using special electronic viewing/measuring equipment

NASA Technical Reports Server (NTRS)

Evans, W. E.; Serebreny, S. M.

1973-01-01

An electronic satellite image analysis console (ESIAC) is being employed to process imagery for use by USGS investigators in several different disciplines studying dynamic hydrologic conditions. The ESIAC provides facilities for storing registered image sequences in a magnetic video disc memory for subsequent recall, enhancement, and animated display in monochrome or color. Quantitative measurements of distances, areas, and brightness profiles can be extracted digitally under operator supervision. Initial results are presented for the display and measurement of snowfield extent, glacier development, sediment plumes from estuary discharge, playa inventory, phreatophyte and other vegetative changes.

Two-dimensional multi-component photometric decomposition of CALIFA galaxies

NASA Astrophysics Data System (ADS)

Méndez-Abreu, J.; Ruiz-Lara, T.; Sánchez-Menguiano, L.; de Lorenzo-Cáceres, A.; Costantin, L.; Catalán-Torrecilla, C.; Florido, E.; Aguerri, J. A. L.; Bland-Hawthorn, J.; Corsini, E. M.; Dettmar, R. J.; Galbany, L.; García-Benito, R.; Marino, R. A.; Márquez, I.; Ortega-Minakata, R. A.; Papaderos, P.; Sánchez, S. F.; Sánchez-Blazquez, P.; Spekkens, K.; van de Ven, G.; Wild, V.; Ziegler, B.

2017-02-01

We present a two-dimensional multi-component photometric decomposition of 404 galaxies from the Calar Alto Legacy Integral Field Area data release 3 (CALIFA-DR3). They represent all possible galaxies with no clear signs of interaction and not strongly inclined in the final CALIFA data release. Galaxies are modelled in the g, r, and I Sloan Digital Sky Survey (SDSS) images including, when appropriate, a nuclear point source, bulge, bar, and an exponential or broken disc component. We use a human-supervised approach to determine the optimal number of structures to be included in the fit. The dataset, including the photometric parameters of the CALIFA sample, is released together with statistical errors and a visual analysis of the quality of each fit. The analysis of the photometric components reveals a clear segregation of the structural composition of galaxies with stellar mass. At high masses (log (M⋆/M⊙) > 11), the galaxy population is dominated by galaxies modelled with a single Sérsic or a bulge+disc with a bulge-to-total (B/T) luminosity ratio B/T > 0.2. At intermediate masses (9.5 < log (M⋆/M⊙) < 11), galaxies described with bulge+disc but B/T < 0.2 are preponderant, whereas, at the low mass end (log (M⋆/M⊙) < 9.5), the prevailing population is constituted by galaxies modelled with either purediscs or nuclear point sources+discs (I.e., no discernible bulge). We obtain that 57% of the volume corrected sample of disc galaxies in the CALIFA sample host a bar. This bar fraction shows a significant drop with increasing galaxy mass in the range 9.5 < log (M⋆/M⊙) < 11.5. The analyses of the extended multi-component radial profile result in a volume-corrected distribution of 62%, 28%, and 10% for the so-called Type I (pure exponential), Type II (down-bending), and Type III (up-bending) disc profiles, respectively. These fractions are in discordance with previous findings. We argue that the different methodologies used to detect the breaks are the main cause for these differences. The catalog of fitted parameters is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/598/A32

Eye-safe digital 3-D sensing for space applications

NASA Astrophysics Data System (ADS)

Beraldin, J.-Angelo; Blais, Francois; Rioux, Marc; Cournoyer, Luc; Laurin, Denis G.; MacLean, Steve G.

2000-01-01

This paper focuses on the characteristics and performance of an eye-safe laser range scanner (LARS) with short- and medium-range 3D sensing capabilities for space applications. This versatile LARS is a precision measurement tool that will complement the current Canadian Space Vision System. The major advantages of the LARS over conventional video- based imaging are its ability to operate with sunlight shining directly into the scanner and its immunity to spurious reflections and shadows, which occur frequently in space. Because the LARS is equipped with two high-speed galvanometers to steer the laser beam, any spatial location within the field of view of the camera can be addressed. This versatility enables the LARS to operate in two basis scan pattern modes: (1) variable-scan-resolution mode and (2) raster-scan mode. In the variable-resolution mode, the LARS can search and track targets and geometrical features on objects located within a field of view of 30 by 30 deg and with corresponding range from about 0.5 to 2000 m. The tracking mode can reach a refresh rate of up to 130 Hz. The raster mode is used primarily for the measurement of registered range and intensity information on large stationary objects. It allows, among other things, target- based measurements, feature-based measurements, and surface- reflectance monitoring. The digitizing and modeling of human subjects, cargo payloads, and environments are also possible with the LARS. Examples illustrating its capabilities are presented.

Integration of a versatile bridge concept in a 34 GHz pulsed/CW EPR spectrometer

NASA Astrophysics Data System (ADS)

Band, Alan; Donohue, Matthew P.; Epel, Boris; Madhu, Shraeya; Szalai, Veronika A.

2018-03-01

We present a 34 GHz continuous wave (CW)/pulsed electron paramagnetic resonance (EPR) spectrometer capable of pulse-shaping that is based on a versatile microwave bridge design. The bridge radio frequency (RF)-in/RF-out design (500 MHz to 1 GHz input/output passband, 500 MHz instantaneous input/output bandwidth) creates a flexible platform with which to compare a variety of excitation and detection methods utilizing commercially available equipment external to the bridge. We use three sources of RF input to implement typical functions associated with CW and pulse EPR spectroscopic measurements. The bridge output is processed via high speed digitizer and an in-phase/quadrature (I/Q) demodulator for pulsed work or sent to a wideband, high dynamic range log detector for CW. Combining this bridge with additional commercial hardware and new acquisition and control electronics, we have designed and constructed an adaptable EPR spectrometer that builds upon previous work in the literature and is functionally comparable to other available systems.

Radiopacity of endodontic materials on film and a digital sensor.

PubMed

Rasimick, Brian J; Shah, Rinal P; Musikant, Barry Lee; Deutsch, Allan S

2007-09-01

The purpose of this study was to compare the radiographic appearance of 12 endodontic materials as visualized on either Kodak Ultra-speed D speed film (Eastman Kodak Company, Rochester, NY) or a Gendex eHD digital sensor (Gendex Dental Systems, Milan, Italy). Ten discs of each material were radiographed alongside an aluminum alloy 1100 (Alcoa, Pittsburgh, PA) stepwedge that was used for reference. For every radiograph, the average grayscale value of the material was converted into absorbance notation and compared with that of the reference stepwedge in order to determine the equivalent radiopacity in terms of millimeters of Al 1100 per millimeter of material. Two-way repeated-measures analysis of variance testing detected significant differences with respect to imaging system, material, and the interaction of the two factors (p < 0.001). The difference in a material's radiopacity as measured on the digital sensor compared with film was greater than 10% for 4 of the 12 materials and over 40% for InnoEndo (Heraus Kulzer, Armonk, NY). It was speculated that barium fillers cause this effect.

Standardization of computer-assisted semen analysis using an e-learning application.

PubMed

Ehlers, J; Behr, M; Bollwein, H; Beyerbach, M; Waberski, D

2011-08-01

Computer-assisted semen analysis (CASA) is primarily used to obtain accurate and objective kinetic sperm measurements. Additionally, AI centers use computer-assessed sperm concentration in the sample as a basis for calculating the number of insemination doses available from a given ejaculate. The reliability of data is often limited and results can vary even when the same CASA systems with identical settings are used. The objective of the present study was to develop a computer-based training module for standardized measurements with a CASA system and to evaluate its training effect on the quality of the assessment of sperm motility and concentration. A digital versatile disc (DVD) has been produced showing the standardization of sample preparation and analysis with the CASA system SpermVision™ version 3.0 (Minitube, Verona, WI, USA) in words, pictures, and videos, as well as the most probable sources of error. Eight test persons educated in spermatology, but with different levels of experience with the CASA system, prepared and assessed 10 aliquots from one prediluted bull ejaculate using the same CASA system and laboratory equipment before and after electronic learning (e-learning). After using the e-learning application, the coefficient of variation was reduced on average for the sperm concentration from 26.1% to 11.3% (P ≤ 0.01), and for motility from 5.8% to 3.1% (P ≤ 0.05). For five test persons, the difference in the coefficient of variation before and after use of the e-learning application was significant (P ≤ 0.05). Individual deviations of means from the group mean before e-learning were reduced compared with individual deviations from the group mean after e-learning. According to a survey, the e-learning application was highly accepted by users. In conclusion, e-learning presents an effective, efficient, and accepted tool for improvement of the precision of CASA measurements. This study provides a model for the standardization of other laboratory procedures using e-learning. Copyright © 2011 Elsevier Inc. All rights reserved.

Digital readout for image converter cameras

NASA Astrophysics Data System (ADS)

Honour, Joseph

1991-04-01

There is an increasing need for fast and reliable analysis of recorded sequences from image converter cameras so that experimental information can be readily evaluated without recourse to more time consuming photographic procedures. A digital readout system has been developed using a randomly triggerable high resolution CCD camera, the output of which is suitable for use with IBM AT compatible PC. Within half a second from receipt of trigger pulse, the frame reformatter displays the image and transfer to storage media can be readily achieved via the PC and dedicated software. Two software programmes offer different levels of image manipulation which includes enhancement routines and parameter calculations with accuracy down to pixel levels. Hard copy prints can be acquired using a specially adapted Polaroid printer, outputs for laser and video printer extend the overall versatility of the system.

In vitro comparison of endplate preparation between four mini-open interbody fusion approaches.

PubMed

Tatsumi, Robert; Lee, Yu-Po; Khajavi, Kaveh; Taylor, William; Chen, Foster; Bae, Hyun

2015-04-01

Discectomy and endplate preparation are important steps in interbody fusion for ensuring sufficient arthrodesis. While modern less-invasive approaches for lumbar interbody fusion have gained in popularity, concerns exist regarding their ability to allow for adequate disc space and endplate preparation. Thus, the purpose of this study was to quantitatively and qualitatively evaluate and compare disc space and endplate preparation achieved with four less-invasive approaches for lumbar interbody fusion in cadaveric spines. A total of 24 disc spaces (48 endplates) from L2 to L5 were prepared in eight cadaveric torsos using mini-open anterior lumbar interbody fusion (mini-ALIF), minimally invasive posterior lumbar interbody fusion (MAS PLIF), minimally invasive transforaminal lumbar interbody fusion (MAS TLIF) or minimally invasive lateral, transpsoas interbody fusion (XLIF) on two specimens each, for a total of six levels and 12 endplates prepared per procedure type. Following complete discectomy and endplate preparation, spines were excised and split axially at the interbody disc spaces. Endplates were digitally photographed and evaluated using image analysis software. Area of endplate preparation was measured and qualitative evaluation was also performed to grade the quality of preparation. The XLIF approach resulted in the greatest relative area of endplate preparation (58.3 %) while mini-ALIF resulted in the lowest at 35.0 %. Overall, there were no differences in percentage of preparation between cranial and caudal endplates, though this was significantly different in the XLIF group (65 vs 52 %, respectively). ALL damage was observed in 3 MAS TLIF levels. Percentage of endplate that was deemed to have complete disc removal was highest in XLIF group with 90 % compared to 65 % in MAS TLIF group, 43 % in MAS PLIF, and 40 % in mini-ALIF group. Endplate damage area was highest in the MAS TLIF group at 48 % and lowest in XLIF group at 4 %. These results demonstrate that adequate endplate preparation for interbody fusion can be achieved utilizing various minimally invasive approach techniques (mini-ALIF, MAS TLIF, MAS PLIF, XLIF), however, XLIF appears to provide a greater area of and more complete endplate preparation.

A randomized trial comparing digital video disc with written delivery of falls prevention education for older patients in hospital.

PubMed

Hill, Anne-Marie; McPhail, Steven; Hoffmann, Tammy; Hill, Keith; Oliver, David; Beer, Christopher; Brauer, Sandra; Haines, Terry P

2009-08-01

To compare the effectiveness of a digital video disc (DVD) with that of a written workbook delivering falls prevention education to older hospital patients on self-perceived risk of falls, perception of falls epidemiology, knowledge of prevention strategies, and motivation and confidence to engage in self-protective strategies. To compare the effect of receiving either education approach versus no education on patients' perception of falls epidemiology. Randomized trial (DVD vs workbook) with additional quasi-experimental control group. Geriatric, medical, and orthopedic wards in Perth and Brisbane, Australia. One hundred (n=51 DVD, n=49 workbook) hospital inpatients aged 60 and older receiving an intervention (mean age 75.3+/-10.1) and 122 in the control group (mean age 79.3+/-8.3). Participants randomly assigned to receive identical educational material on falls prevention delivered on a DVD or in a workbook. Control group received usual care. Custom-designed survey addressing elements of the Health Belief Model of health behavior change. Participants randomized to DVD delivery had a higher self-perceived risk of falling (P=.04) and higher levels of confidence (P=.03) and motivation (P=.04) to engage in self-protective strategies than participants who received the workbook. A higher proportion of participants who received either form of the education provided "desired" responses than of control group participants across all knowledge items (P<.001). Delivery of falls prevention education on a DVD compared to a written workbook is more likely to achieve important changes in parameters likely to affect successful uptake of falls prevention messages in the hospital setting.

Computerized analysis and duplication of mandibular motion.

PubMed

Knap, F J; Abler, J H; Richardson, B L

1975-05-01

A new digital system has been devised to analyze and duplicate jaw motion. The arrangement of the electronic system offers a range of versatility which includes graphic as well as numerical data analysis. The duplicator linkage is identical to the sensor linkage which, together with an accurate model transfer system, results in an encouraging level of accuracy in jaw-motion duplication. The data collected from normal subjects should offer some new knowledge in the normal motions of the mandible as well as establish a reference for comparison with abnormal masticatory function.

A versatile pulse programmer for pulsed nuclear magnetic resonance spectroscopy.

NASA Technical Reports Server (NTRS)

Tarr, C. E.; Nickerson, M. A.

1972-01-01

A digital pulse programmer producing the standard pulse sequences required for pulsed nuclear magnetic resonance spectroscopy is described. In addition, a 'saturation burst' sequence, useful in the measurement of long relaxation times in solids, is provided. Both positive and negative 4 V trigger pulses are produced that are fully synchronous with a crystal-controlled time base, and the pulse programmer may be phase-locked with a maximum pulse jitter of 3 ns to the oscillator of a coherent pulse spectrometer. Medium speed TTL integrated circuits are used throughout.

First spectra from a new, wide band, hybrid digital correlator spectrometer for the FIRST-HIFI instrument.

NASA Astrophysics Data System (ADS)

Cais, P.; Ravera, L.; Lagrange, D.; Giard, M.; Baudry, A.; Mayvial, J. Y.

1998-11-01

The authors have designed and built a new, wide band, modulable resolution spectrometer, in view of full astronomical qualifying tests, and to prepare future models for the FIRST satellite's heterodyne instrument. The spectrometer, a hybrid digital autocorrelator, offers flexibility in terms of bandwidth (from 170 MHz to 680 MHz) and resolution (from 700 kHz to 3 MHz). This spectrometer required the development of a dedicated analog filter bank, homemade samplers, and the design of full custom GaAs integrated circuits. Laboratory tests have shown excellent agreement with expected performances and observations performed with the IRAM 30-m radiotelescope have qualified its capabilities. Despite the relatively limited number of channels of the current prototype compared to other spectrometers, the main advantages are its stability (inherent to digital technique), and its spectral versatility. Microelectronics advances and rad-tolerance of the spectrometer components are used to prepare a new, compact, and low power consumption autocorrelator in view of a flight model for HIFI, the heterodyne instrument on the ESA cornerstone mission FIRST.

Accurate and agile digital control of optical phase, amplitude and frequency for coherent atomic manipulation of atomic systems.

PubMed

Thom, Joseph; Wilpers, Guido; Riis, Erling; Sinclair, Alastair G

2013-08-12

We demonstrate a system for fast and agile digital control of laser phase, amplitude and frequency for applications in coherent atomic systems. The full versatility of a direct digital synthesis radiofrequency source is faithfully transferred to laser radiation via acousto-optic modulation. Optical beatnotes are used to measure phase steps up to 2π, which are accurately implemented with a resolution of ≤ 10 mrad. By linearizing the optical modulation process, amplitude-shaped pulses of durations ranging from 500 ns to 500 ms, in excellent agreement with the programmed functional form, are demonstrated. Pulse durations are limited only by the 30 ns rise time of the modulation process, and a measured extinction ratio of > 5 × 10(11) is achieved. The system presented here was developed specifically for controlling the quantum state of trapped ions with sequences of multiple laser pulses, including composite and bichromatic pulses. The demonstrated techniques are widely applicable to other atomic systems ranging across quantum information processing, frequency metrology, atom interferometry, and single-photon generation.

Digital Imprinting of RNA Recognition and Processing on a Self-Assembled Nucleic Acid Matrix

NASA Astrophysics Data System (ADS)

Redhu, Shiv K.; Castronovo, Matteo; Nicholson, Allen W.

2013-08-01

The accelerating progress of research in nanomedicine and nanobiotechnology has included initiatives to develop highly-sensitive, high-throughput methods to detect biomarkers at the single-cell level. Current sensing approaches, however, typically involve integrative instrumentation that necessarily must balance sensitivity with rapidity in optimizing biomarker detection quality. We show here that laterally-confined, self-assembled monolayers of a short, double-stranded(ds)[RNA-DNA] chimera enable permanent digital detection of dsRNA-specific inputs. The action of ribonuclease III and the binding of an inactive, dsRNA-binding mutant can be permanently recorded by the input-responsive action of a restriction endonuclease that cleaves an ancillary reporter site within the dsDNA segment. The resulting irreversible height change of the arrayed ds[RNA-DNA], as measured by atomic force microscopy, provides a distinct digital output for each dsRNA-specific input. These findings provide the basis for developing imprinting-based bio-nanosensors, and reveal the versatility of AFM as a tool for characterizing the behaviour of highly-crowded biomolecules at the nanoscale.

Disc piezoelectric ceramic transformers.

PubMed

Erhart, Jirií; Půlpán, Petr; Doleček, Roman; Psota, Pavel; Lédl, Vít

2013-08-01

In this contribution, we present our study on disc-shaped and homogeneously poled piezoelectric ceramic transformers working in planar-extensional vibration modes. Transformers are designed with electrodes divided into wedge, axisymmetrical ring-dot, moonie, smile, or yin-yang segments. Transformation ratio, efficiency, and input and output impedances were measured for low-power signals. Transformer efficiency and transformation ratio were measured as a function of frequency and impedance load in the secondary circuit. Optimum impedance for the maximum efficiency has been found. Maximum efficiency and no-load transformation ratio can reach almost 100% and 52 for the fundamental resonance of ring-dot transformers and 98% and 67 for the second resonance of 2-segment wedge transformers. Maximum efficiency was reached at optimum impedance, which is in the range from 500 Ω to 10 kΩ, depending on the electrode pattern and size. Fundamental vibration mode and its overtones were further studied using frequency-modulated digital holographic interferometry and by the finite element method. Complementary information has been obtained by the infrared camera visualization of surface temperature profiles at higher driving power.

Data Recovery Effort of Nimbus Era Observations by the NASA GES DISC

NASA Technical Reports Server (NTRS)

Johnson, James; Esfandiari, Ed; Zamkoff, Emily; Gerasimov, Irina; Al-Jazrawi, Atheer; Alcott, Gary

2017-01-01

NASA launched seven Nimbus meteorological satellites in the 1960s and 70s. These satellites carried instruments for making observations of the Earth in the visible, infrared, ultraviolet, and microwave wavelengths. The original data archive consisted of a combination of magnetic tapes and various film media. As these media are well past their expected end of life, the valuable data they contain are now being migrated to the GES DISC modern online archive. The process involves recovering the digital data files from the tapes as well as scanning images of the data from film strips. This presentation will address the status and challenges of recovering the Nimbus data. The old data products were written on now obsolete hardware systems and outdated file formats. They lack any metadata standards and each product is often written in its own proprietary file structure. This requires creating metadata by reading the contents of the old data files. The job is tedious and laborious, as documentation may be incomplete, data files and tapes are sometimes corrupted, or were improperly copied at the time they were created.

Cresting the wave: proper motions of the Eastern Banded Structure

NASA Astrophysics Data System (ADS)

Deason, Alis J.; Belokurov, Vasily; Koposov, Sergey E.

2018-01-01

We study the kinematic properties of the Eastern Banded Structure (EBS) and Hydra I overdensity using exquisite proper motions derived from the Sloan Digital Sky Survey (SDSS) and Gaia source catalogue. Main sequence turn-off stars in the vicinity of the EBS are identified from SDSS photometry; we use the proper motions and, where applicable, spectroscopic measurements of these stars to probe the kinematics of this apparent stream. We find that the EBS and Hydra I share common kinematic and chemical properties with the nearby Monoceros Ring. In particular, the proper motions of the EBS, like Monoceros, are indicative of prograde rotation (Vϕ ∼ 180-220 km s-1), which is similar to the Galactic thick disc. The kinematic structure of stars in the vicinity of the EBS suggests that it is not a distinct stellar stream, but rather marks the 'edge' of the Monoceros Ring. The EBS and Hydra I are the latest substructures to be linked with Monoceros, leaving the Galactic anti-centre a mess of interlinked overdensities which likely share a unified, Galactic disc origin.

Effect of metal chloride solutions on coloration and biaxial flexural strength of yttria-stabilized zirconia

NASA Astrophysics Data System (ADS)

Oh, Gye-Jeong; Lee, Kwangmin; Lee, Doh-Jae; Lim, Hyun-Pil; Yun, Kwi-Dug; Ban, Jae-Sam; Lee, Kyung-Ku; Fisher, John G.; Park, Sang-Won

2012-10-01

The effect of three kinds of transition metal dopants on the color and biaxial flexural strength of zirconia ceramics for dental applications was evaluated. Presintered zirconia discs were colored through immersion in aqueous chromium, molybdenum and vanadium chloride solutions and then sintered at 1450 °C. The color of the doped specimens was measured using a digital spectrophotometer. For biaxial flexural strength measurements, specimens infiltrated with 0.3 wt% of each aqueous chloride solution were used. Uncolored discs were used as a control. Zirconia specimens infiltrated with chromium, molybdenum and vanadium chloride solutions were dark brown, light yellow and dark yellow, respectively. CIE L*, a*, and b* values of all the chromium-doped specimens and the specimens infiltrated with 0.1 wt% molybdenum chloride solution were in the range of values for natural teeth. The biaxial flexural strengths of the three kinds of metal chloride groups were similar to the uncolored group. These results suggest that chromium and molybdenum dopants can be used as colorants to fabricate tooth colored zirconia ceramic restorations.

Digital Audio Radio Broadcast Systems Laboratory Testing Nearly Complete

NASA Technical Reports Server (NTRS)

2005-01-01

Radio history continues to be made at the NASA Lewis Research Center with the completion of phase one of the digital audio radio (DAR) testing conducted by the Consumer Electronics Group of the Electronic Industries Association. This satellite, satellite/terrestrial, and terrestrial digital technology will open up new audio broadcasting opportunities both domestically and worldwide. It will significantly improve the current quality of amplitude-modulated/frequency-modulated (AM/FM) radio with a new digitally modulated radio signal and will introduce true compact-disc-quality (CD-quality) sound for the first time. Lewis is hosting the laboratory testing of seven proposed digital audio radio systems and modes. Two of the proposed systems operate in two modes each, making a total of nine systems being tested. The nine systems are divided into the following types of transmission: in-band on-channel (IBOC), in-band adjacent-channel (IBAC), and new bands. The laboratory testing was conducted by the Consumer Electronics Group of the Electronic Industries Association. Subjective assessments of the audio recordings for each of the nine systems was conducted by the Communications Research Center in Ottawa, Canada, under contract to the Electronic Industries Association. The Communications Research Center has the only CCIR-qualified (Consultative Committee for International Radio) audio testing facility in North America. The main goals of the U.S. testing process are to (1) provide technical data to the Federal Communication Commission (FCC) so that it can establish a standard for digital audio receivers and transmitters and (2) provide the receiver and transmitter industries with the proper standards upon which to build their equipment. In addition, the data will be forwarded to the International Telecommunications Union to help in the establishment of international standards for digital audio receivers and transmitters, thus allowing U.S. manufacturers to compete in the world market.

Improved initial guess with semi-subpixel level accuracy in digital image correlation by feature-based method

NASA Astrophysics Data System (ADS)

Zhang, Yunlu; Yan, Lei; Liou, Frank

2018-05-01

The quality initial guess of deformation parameters in digital image correlation (DIC) has a serious impact on convergence, robustness, and efficiency of the following subpixel level searching stage. In this work, an improved feature-based initial guess (FB-IG) scheme is presented to provide initial guess for points of interest (POIs) inside a large region. Oriented FAST and Rotated BRIEF (ORB) features are semi-uniformly extracted from the region of interest (ROI) and matched to provide initial deformation information. False matched pairs are eliminated by the novel feature guided Gaussian mixture model (FG-GMM) point set registration algorithm, and nonuniform deformation parameters of the versatile reproducing kernel Hilbert space (RKHS) function are calculated simultaneously. Validations on simulated images and real-world mini tensile test verify that this scheme can robustly and accurately compute initial guesses with semi-subpixel level accuracy in cases with small or large translation, deformation, or rotation.

Design and Evaluation of a Personal Digital Assistant-based Research Platform for Cochlear Implants

PubMed Central

Ali, Hussnain; Lobo, Arthur P.; Loizou, Philipos C.

2014-01-01

This paper discusses the design, development, features, and clinical evaluation of a personal digital assistant (PDA)-based platform for cochlear implant research. This highly versatile and portable research platform allows researchers to design and perform complex experiments with cochlear implants manufactured by Cochlear Corporation with great ease and flexibility. The research platform includes a portable processor for implementing and evaluating novel speech processing algorithms, a stimulator unit which can be used for electrical stimulation and neurophysio-logic studies with animals, and a recording unit for collecting electroencephalogram/evoked potentials from human subjects. The design of the platform for real time and offline stimulation modes is discussed for electric-only and electric plus acoustic stimulation followed by results from an acute study with implant users for speech intelligibility in quiet and noisy conditions. The results are comparable with users’ clinical processor and very promising for undertaking chronic studies. PMID:23674422

Design of a high-speed digital processing element for parallel simulation

NASA Technical Reports Server (NTRS)

Milner, E. J.; Cwynar, D. S.

1983-01-01

A prototype of a custom designed computer to be used as a processing element in a multiprocessor based jet engine simulator is described. The purpose of the custom design was to give the computer the speed and versatility required to simulate a jet engine in real time. Real time simulations are needed for closed loop testing of digital electronic engine controls. The prototype computer has a microcycle time of 133 nanoseconds. This speed was achieved by: prefetching the next instruction while the current one is executing, transporting data using high speed data busses, and using state of the art components such as a very large scale integration (VLSI) multiplier. Included are discussions of processing element requirements, design philosophy, the architecture of the custom designed processing element, the comprehensive instruction set, the diagnostic support software, and the development status of the custom design.

Digital Optical Control System

NASA Astrophysics Data System (ADS)

Jordan, David H.; Tipton, Charles A.; Christmann, Charles E.; Hochhausler, Nils P.

1988-09-01

We describe the digital optical control system (DOGS), a state-of-the-art controller for electrical feedback in an optical system. The need for a versatile optical controller arose from a number of unique experiments being performed by the Air Force Weapons Laboratory. These experiments use similar detectors and actuator-controlled mirrors, but the control requirements vary greatly. The experiments have in common a requirement for parallel control systems. The DOGS satisfies these needs by allowing several control systems to occupy a single chassis with one master controller. The architecture was designed to allow upward compatibility with future configurations. Combinations of off-the-shelf and custom boards are configured to meet the requirements of each experiment. The configuration described here was used to control piston error to X/80 at a wavelength of 0.51 Am. A peak sample rate of 8 kHz, yielding a closed loop bandwidth of 800 Hz, was achieved.

Review of Use and Integration of Mobile Apps Into Psychiatric Treatments.

PubMed

Chan, Steven; Godwin, Haley; Gonzalez, Alvaro; Yellowlees, Peter M; Hilty, Donald M

2017-10-30

Mental health practitioners should understand the features of current, publicly available apps; the features of novel, research apps; and issues behind the integration of mobile apps and digital health services into clinical workflows. The review is based on a research literature and the authors' clinical and healthcare administration experiences. Articles searched-on telepsychiatry, telemental health, mobile mental health, informatics, cellular phone, ambulatory monitoring, telemetry, and algorithms-were restricted to 2016 and 2017. Technologies are used in a variety of clinical settings, including patients with varying mental illness severity, social supports, and technological literacy. Good practices for evaluating apps, understanding user needs, and training and educating users can increase success rates. Ethics and risk management should be considered. Mobile apps are versatile. Integrating apps into psychiatric treatment requires addressing both patient and clinical workflows, design and usability principles, accessibility, social concerns, and digital health literacy.

LOFT data acquisition and visual display system (DAVDS) presentation program

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

Bullock, M.G.; Miyasaki, F.S.

1976-03-01

The Data Acquisition and Visual Display System (DAVDS) at the Loss-of-Fluid Test Facility (LOFT) has 742 data channel recording capability of which 576 are recorded digitally. The purpose of this computer program is to graphically present the data acquired and/or processed by the LOFT DAVDS. This program takes specially created plot data buffers of up to 1024 words and generates time history plots on the system electrostatic printer-plotter. The data can be extracted from two system input devices: Magnetic disk or digital magnetic tape. Versatility has been designed in the program by providing the user three methods of scaling plots:more » Automatic, control record, and manual. Time required to produce a plot on the system electrostatic printer-plotter varies from 30 to 90 seconds depending on the options selected. The basic computer and program details are described.« less

Digital microfluidics: A promising technique for biochemical applications

NASA Astrophysics Data System (ADS)

Wang, He; Chen, Liguo; Sun, Lining

2017-12-01

Digital microfluidics (DMF) is a versatile microfluidics technology that has significant application potential in the areas of automation and miniaturization. In DMF, discrete droplets containing samples and reagents are controlled to implement a series of operations via electrowetting-on-dielectric. This process works by applying electrical potentials to an array of electrodes coated with a hydrophobic dielectric layer. Unlike microchannels, DMF facilitates precise control over multiple reaction processes without using complex pump, microvalve, and tubing networks. DMF also presents other distinct features, such as portability, less sample consumption, shorter chemical reaction time, flexibility, and easier combination with other technology types. Due to its unique advantages, DMF has been applied to a broad range of fields (e.g., chemistry, biology, medicine, and environment). This study reviews the basic principles of droplet actuation, configuration design, and fabrication of the DMF device, as well as discusses the latest progress in DMF from the biochemistry perspective.

Policies and Procedures for Accessing Archived NASA Lunar Data via the Web

NASA Technical Reports Server (NTRS)

James, Nathan L.; Williams, David R.

2011-01-01

The National Space Science Data Center (NSSDC) was established by NASA to provide for the preservation and dissemination of scientific data from NASA missions. This paper describes the policies specifically related to lunar science data. NSSDC presently archives 660 lunar data collections. Most of these data (423 units) are stored offline in analog format. The remainder of this collection consists of magnetic tapes and discs containing approximately 1.7 TB of digital lunar data. The active archive for NASA lunar data is the Planetary Data System (PDS). NSSDC has an agreement with the PDS Lunar Data Node to assist in the restoration and preparation of NSSDC-resident lunar data upon request for access and distribution via the PDS archival system. Though much of NSSDC's digital store also resides in PDS, NSSDC has many analog data collections and some digital lunar data sets that are not in PDS. NSSDC stands ready to make these archived lunar data accessible to both the research community and the general public upon request as resources allow. Newly requested offline lunar data are digitized and moved to near-line storage devices called digital linear tape jukeboxes. The data are then packaged and made network-accessible via FTP for the convenience of a growing segment of the user community. This publication will 1) discuss the NSSDC processes and policies that govern how NASA lunar data is preserved, restored, and made accessible via the web and 2) highlight examples of special lunar data requests.

The role of transient receptor potential channels in joint diseases.

PubMed

Krupkova, O; Zvick, J; Wuertz-Kozak, K

2017-10-10

Transient receptor potential channels (TRP channels) are cation selective transmembrane receptors with diverse structures, activation mechanisms and physiological functions. TRP channels act as cellular sensors for a plethora of stimuli, including temperature, membrane voltage, oxidative stress, mechanical stimuli, pH and endogenous, as well as, exogenous ligands, thereby illustrating their versatility. As such, TRP channels regulate various functions in both excitable and non-excitable cells, mainly by mediating Ca2+ homeostasis. Dysregulation of TRP channels is implicated in many pathologies, including cardiovascular diseases, muscular dystrophies and hyperalgesia. However, the importance of TRP channel expression, physiological function and regulation in chondrocytes and intervertebral disc (IVD) cells is largely unexplored. Osteoarthritis (OA) and degenerative disc disease (DDD) are chronic age-related disorders that significantly affect the quality of life by causing pain, activity limitation and disability. Furthermore, currently available therapies cannot effectively slow-down or stop progression of these diseases. Both OA and DDD are characterised by reduced tissue cellularity, enhanced inflammatory responses and molecular, structural and mechanical alterations of the extracellular matrix, hence affecting load distribution and reducing joint flexibility. However, knowledge on how chondrocytes and IVD cells sense their microenvironment and respond to its changes is still limited. In this review, we introduced six families of mammalian TRP channels, their mechanisms of activation, as well as, activation-driven cellular consequences. We summarised the current knowledge on TRP channel expression and activity in chondrocytes and IVD cells, as well as, the significance of TRP channels as therapeutic targets for the treatment of OA and DDD.

Reading disc-based bioassays with standard computer drives.

PubMed

Yu, Hua-Zhong; Li, Yunchao; Ou, Lily M-L

2013-02-19

Traditional methods of disease diagnosis are both time-consuming and labor-intensive, and many tests require expensive instrumentation and trained professionals, which restricts their use to biomedical laboratories. Because patients can wait several days (even weeks) for the results, the consequences of delayed treatment could be disastrous. Therefore, affordable and simple point-of-care (POC) biosensor devices could fill a diagnostic niche in the clinic or even at home, as personal glucose meters do for diabetics. These devices would allow patients to check their own health conditions and enable physicians to make prompt treatment decisions, which could improve the chances for rapid recovery and cure. Compact discs (CDs) provide inexpensive substrate materials for the preparation of microarray biochips, and conventional computer drives/disc players can be adapted as precise optical reading devices for signal processing. Researchers can employ the polycarbonate (PC) base of a CD as an alternative substrate to glass slides or silicon wafers for the preparation of microanalytical devices. Using the characteristic optical phenomena occurring on the metal layer of a CD, researchers can develop biosensors based on advanced spectroscopic readout (interferometry or surface plasmon resonance). If researchers integrate microfluidic functions with CD mechanics, they can control fluid transfer through the spinning motion of the disc, leading to "lab-on-a-CD" devices. Over the last decade, our laboratory has focused on the construction of POC biosensor devices from off-the-shelf CDs or DVDs and standard computer drives. Besides the initial studies of the suitability of CDs for surface and materials chemistry research (fabrication of self-assembled monolayers and oxide nanostructures), we have demonstrated that an ordinary optical drive, without modification of either the hardware or the software driver, can function as the signal transducing element for reading disc-based bioassays quantitatively. In this Account, we first provide a brief introduction to CD-related materials chemistry and microfluidics research. Then we describe the mild chemistry developed in our laboratory for the preparation of computer-readable biomolecular screening assays: photochemical activation of the polycarbonate (PC) disc surface and immobilization and delivery of probe and target biomolecules. We thoroughly discuss the analysis of the molecular recognition events: researchers can "read" these devices quantitatively with an unmodified optical drive of any personal computer. Finally, and critically, we illustrate our digitized molecular diagnosis approach with three trial systems: DNA hybridization, antibody-antigen binding, and ultrasensitive lead detection with a DNAzyme assay. These examples demonstrate the broad potential of this new analytical/diagnostic tool for medical screening, on-site food/water safety testing, and remote environmental monitoring.

Method to Enhance the Operation of an Optical Inspection Instrument Using Spatial Light Modulators

NASA Technical Reports Server (NTRS)

Trolinger, James; Lal, Amit; Jo, Joshua; Kupiec, Stephen

2012-01-01

For many aspheric and freeform optical components, existing interferometric solutions require a custom computer-generated hologram (CGH) to characterize the part. The overall objective of this research is to develop hardware and a procedure to produce a combined, dynamic, Hartmann/ Digital Holographic interferometry inspection system for a wide range of advanced optical components, including aspheric and freeform optics. This new instrument would have greater versatility and dynamic range than currently available measurement systems. The method uses a spatial light modulator to pre-condition wavefronts for imaging, interferometry, and data processing to improve the resolution and versatility of an optical inspection instrument. Existing interferometers and Hartmann inspection systems have either too small a dynamic range or insufficient resolution to characterize conveniently unusual optical surfaces like aspherical and freeform optics. For interferometers, a specially produced, computer-generated holographic optical element is needed to transform the wavefront to within the range of the interferometer. A new hybrid wavefront sensor employs newly available spatial light modulators (SLMs) as programmable holographic optical elements (HOEs). The HOE is programmed to enable the same instrument to inspect an optical element in stages, first by a Hartmann measurement, which has a very large dynamic range but less resolution. The first measurement provides the information required to precondition a reference wave that avails the measurement process to the more precise phase shifting interferometry. The SLM preconditions a wavefront before it is used to inspect an optical component. This adds important features to an optical inspection system, enabling not just wavefront conditioning for null testing and dynamic range extension, but also the creation of hybrid measurement procedures. This, for example, allows the combination of dynamic digital holography and Hartmann sensing procedures to cover a virtually unlimited dynamic range with high resolution. Digital holography technology brings all of the power and benefits of digital holographic interferometry to the requirement, while Hartmann-type wavefront sensors bring deflectometry technologies to the solution. The SLM can be used to generate arbitrary wavefronts in one leg of the interferometer, thereby greatly simplifying its use and extending its range. The SLM can also be used to modify the system into a dynamic Shack-Hartmann system, which is useful for optical components with large amounts of slope. By integrating these capabilities into a single instrument, the system will have tremendous flexibility to measure a variety of optical shapes accurately.

Directional sensitivity of the retina: A layered scattering model of outer-segment photoreceptor pigments

PubMed Central

Vohnsen, Brian

2014-01-01

Photoreceptor outer segments have been modeled as stacked arrays of discs or membrane infoldings containing visual pigments with light-induced dipole moments. Waveguiding has been excluded so fields diffract beyond the physical boundaries of each photoreceptor cell. Optical reciprocity is used to argue for identical radiative and light gathering properties of pigments to model vision. Two models have been introduced: one a macroscopic model that assumes a uniform pigment density across each layer and another microscopic model that includes the spatial location of each pigment molecule within each layer. Both models result in highly similar directionality at the pupil plane which proves to be insensitive to the exact details of the outer-segment packing being predominantly determined by the first and last contributing layers as set by the fraction of bleaching. The versatility of the microscopic model is demonstrated with an array of examples that includes the Stiles-Crawford effect, visibility of a focused beam of light and the role of defocus. PMID:24877016

Protoplast isolation, transient transformation of leaf mesophyll protoplasts and improved Agrobacterium-mediated leaf disc infiltration of Phaseolus vulgaris: tools for rapid gene expression analysis.

PubMed

Nanjareddy, Kalpana; Arthikala, Manoj-Kumar; Blanco, Lourdes; Arellano, Elizabeth S; Lara, Miguel

2016-06-24

Phaseolus vulgaris is one of the most extensively studied model legumes in the world. The P. vulgaris genome sequence is available; therefore, the need for an efficient and rapid transformation system is more imperative than ever. The functional characterization of P. vulgaris genes is impeded chiefly due to the non-amenable nature of Phaseolus sp. to stable genetic transformation. Transient transformation systems are convenient and versatile alternatives for rapid gene functional characterization studies. Hence, the present work focuses on standardizing methodologies for protoplast isolation from multiple tissues and transient transformation protocols for rapid gene expression analysis in the recalcitrant grain legume P. vulgaris. Herein, we provide methodologies for the high-throughput isolation of leaf mesophyll-, flower petal-, hypocotyl-, root- and nodule-derived protoplasts from P. vulgaris. The highly efficient polyethylene glycol-mannitol magnesium (PEG-MMG)-mediated transformation of leaf mesophyll protoplasts was optimized using a GUS reporter gene. We used the P. vulgaris SNF1-related protein kinase 1 (PvSnRK1) gene as proof of concept to demonstrate rapid gene functional analysis. An RT-qPCR analysis of protoplasts that had been transformed with PvSnRK1-RNAi and PvSnRK1-OE vectors showed the significant downregulation and ectopic constitutive expression (overexpression), respectively, of the PvSnRK1 transcript. We also demonstrated an improved transient transformation approach, sonication-assisted Agrobacterium-mediated transformation (SAAT), for the leaf disc infiltration of P. vulgaris. Interestingly, this method resulted in a 90 % transformation efficiency and transformed 60-85 % of the cells in a given area of the leaf surface. The constitutive expression of YFP further confirmed the amenability of the system to gene functional characterization studies. We present simple and efficient methodologies for protoplast isolation from multiple P. vulgaris tissues. We also provide a high-efficiency and amenable method for leaf mesophyll transformation for rapid gene functional characterization studies. Furthermore, a modified SAAT leaf disc infiltration approach aids in validating genes and their functions. Together, these methods help to rapidly unravel novel gene functions and are promising tools for P. vulgaris research.

A simple and versatile data acquisition system for software coincidence and pulse-height discrimination in 4πβ-γ coincidence experiments.

PubMed

Kawada, Y; Yamada, T; Unno, Y; Yunoki, A; Sato, Y; Hino, Y

2012-09-01

A simple but versatile data acquisition system for software coincidence experiments is described, in which any time stamping and live time controller are not provided. Signals from β- and γ-channels are fed to separately two fast ADCs (16 bits, 25 MHz clock maximum) via variable delay circuits and pulse-height stretchers, and also to pulse-height discriminators. The discriminating level was set to just above the electronic noise. Two ADCs were controlled with a common clock signal, and triggered simultaneously by the logic OR pulses from both discriminators. Paired digital signals for each sampling were sent to buffer memories connected to main PC with a FIFO (First-In, First-Out) pipe via USB. After data acquisition in list mode, various processing including pulse-height analyses was performed using MS-Excel (version 2007 and later). The usefulness of this system was demonstrated for 4πβ(PS)-4πγ coincidence measurements of (60)Co, (134)Cs and (152)Eu. Possibilities of other extended applications will be touched upon. Copyright © 2012 Elsevier Ltd. All rights reserved.

Integration of a versatile bridge concept in a 34 GHz pulsed/CW EPR spectrometer.

PubMed

Band, Alan; Donohue, Matthew P; Epel, Boris; Madhu, Shraeya; Szalai, Veronika A

2018-03-01

We present a 34 GHz continuous wave (CW)/pulsed electron paramagnetic resonance (EPR) spectrometer capable of pulse-shaping that is based on a versatile microwave bridge design. The bridge radio frequency (RF)-in/RF-out design (500 MHz to 1 GHz input/output passband, 500 MHz instantaneous input/output bandwidth) creates a flexible platform with which to compare a variety of excitation and detection methods utilizing commercially available equipment external to the bridge. We use three sources of RF input to implement typical functions associated with CW and pulse EPR spectroscopic measurements. The bridge output is processed via high speed digitizer and an in-phase/quadrature (I/Q) demodulator for pulsed work or sent to a wideband, high dynamic range log detector for CW. Combining this bridge with additional commercial hardware and new acquisition and control electronics, we have designed and constructed an adaptable EPR spectrometer that builds upon previous work in the literature and is functionally comparable to other available systems. Published by Elsevier Inc.

Automatic Detection of Diabetic Retinopathy and Age-Related Macular Degeneration in Digital Fundus Images

PubMed Central

Barriga, E. Simon; Murray, Victor; Nemeth, Sheila; Crammer, Robert; Bauman, Wendall; Zamora, Gilberto; Pattichis, Marios S.; Soliz, Peter

2011-01-01

Purpose. To describe and evaluate the performance of an algorithm that automatically classifies images with pathologic features commonly found in diabetic retinopathy (DR) and age-related macular degeneration (AMD). Methods. Retinal digital photographs (N = 2247) of three fields of view (FOV) were obtained of the eyes of 822 patients at two centers: The Retina Institute of South Texas (RIST, San Antonio, TX) and The University of Texas Health Science Center San Antonio (UTHSCSA). Ground truth was provided for the presence of pathologic conditions, including microaneurysms, hemorrhages, exudates, neovascularization in the optic disc and elsewhere, drusen, abnormal pigmentation, and geographic atrophy. The algorithm was used to report on the presence or absence of disease. A detection threshold was applied to obtain different values of sensitivity and specificity with respect to ground truth and to construct a receiver operating characteristic (ROC) curve. Results. The system achieved an average area under the ROC curve (AUC) of 0.89 for detection of DR and of 0.92 for detection of sight-threatening DR (STDR). With a fixed specificity of 0.50, the system's sensitivity ranged from 0.92 for all DR cases to 1.00 for clinically significant macular edema (CSME). Conclusions. A computer-aided algorithm was trained to detect different types of pathologic retinal conditions. The cases of hard exudates within 1 disc diameter (DD) of the fovea (surrogate for CSME) were detected with very high accuracy (sensitivity = 1, specificity = 0.50), whereas mild nonproliferative DR was the most challenging condition (sensitivity= 0.92, specificity = 0.50). The algorithm was also tested on images with signs of AMD, achieving a performance of AUC of 0.84 (sensitivity = 0.94, specificity = 0.50). PMID:21666234

Automatic detection of diabetic retinopathy and age-related macular degeneration in digital fundus images.

PubMed

Agurto, Carla; Barriga, E Simon; Murray, Victor; Nemeth, Sheila; Crammer, Robert; Bauman, Wendall; Zamora, Gilberto; Pattichis, Marios S; Soliz, Peter

2011-07-29

To describe and evaluate the performance of an algorithm that automatically classifies images with pathologic features commonly found in diabetic retinopathy (DR) and age-related macular degeneration (AMD). Retinal digital photographs (N = 2247) of three fields of view (FOV) were obtained of the eyes of 822 patients at two centers: The Retina Institute of South Texas (RIST, San Antonio, TX) and The University of Texas Health Science Center San Antonio (UTHSCSA). Ground truth was provided for the presence of pathologic conditions, including microaneurysms, hemorrhages, exudates, neovascularization in the optic disc and elsewhere, drusen, abnormal pigmentation, and geographic atrophy. The algorithm was used to report on the presence or absence of disease. A detection threshold was applied to obtain different values of sensitivity and specificity with respect to ground truth and to construct a receiver operating characteristic (ROC) curve. The system achieved an average area under the ROC curve (AUC) of 0.89 for detection of DR and of 0.92 for detection of sight-threatening DR (STDR). With a fixed specificity of 0.50, the system's sensitivity ranged from 0.92 for all DR cases to 1.00 for clinically significant macular edema (CSME). A computer-aided algorithm was trained to detect different types of pathologic retinal conditions. The cases of hard exudates within 1 disc diameter (DD) of the fovea (surrogate for CSME) were detected with very high accuracy (sensitivity = 1, specificity = 0.50), whereas mild nonproliferative DR was the most challenging condition (sensitivity = 0.92, specificity = 0.50). The algorithm was also tested on images with signs of AMD, achieving a performance of AUC of 0.84 (sensitivity = 0.94, specificity = 0.50).

Automatic determination of the artery vein ratio in retinal images

NASA Astrophysics Data System (ADS)

Niemeijer, Meindert; van Ginneken, Bram; Abràmoff, Michael D.

2010-03-01

A lower ratio between the width of the arteries and veins (Arteriolar-to-Venular diameter Ratio, AVR) on the retina, is well established to be predictive of stroke and other cardiovascular events in adults, as well as an increased risk of retinopathy of prematurity in premature infants. This work presents an automatic method that detects the location of the optic disc, determines the appropriate region of interest (ROI), classifies the vessels in the ROI into arteries and veins, measures their widths and calculates the AVR. After vessel segmentation and vessel width determination the optic disc is located and the system eliminates all vessels outside the AVR measurement ROI. The remaining vessels are thinned, vessel crossing and bifurcation points are removed leaving a set of vessel segments containing centerline pixels. Features are extracted from each centerline pixel that are used to assign them a soft label indicating the likelihood the pixel is part of a vein. As all centerline pixels in a connected segment should be the same type, the median soft label is assigned to each centerline pixel in the segment. Next artery vein pairs are matched using an iterative algorithm and the widths of the vessels is used to calculate the AVR. We train and test the algorithm using a set of 25 high resolution digital color fundus photographs a reference standard that indicates for the major vessels in the images whether they are an artery or a vein. We compared the AVR values produced by our system with those determined using a computer assisted method in 15 high resolution digital color fundus photographs and obtained a correlation coefficient of 0.881.

DA white dwarfs in Sloan Digital Sky Survey Data Release 7 and a search for infrared excess emission

NASA Astrophysics Data System (ADS)

Girven, J.; Gänsicke, B. T.; Steeghs, D.; Koester, D.

2011-10-01

We present a method which uses colour-colour cuts on the Sloan Digital Sky Survey (SDSS) photometry to select white dwarfs with hydrogen-rich (DA) atmospheres without the recourse to spectroscopy. This method results in a sample of DA white dwarfs that is 95 per cent complete at an efficiency of returning a true DA white dwarf of 62 per cent. The approach was applied to SDSS Data Release 7 for objects with and without SDSS spectroscopy. This led to 4636 spectroscopicially confirmed DA white dwarfs with g≤ 19; a ˜70 per cent increase compared to Eisenstein et al.'s 2006 sample. Including the photometric-only objects, we estimate a factor of 3 increase in DA white dwarfs. We find that the SDSS spectroscopic follow-up is 44 per cent complete for DA white dwarfs with Teff≳ 8000 K. We further cross-correlated the SDSS sample with Data Release 8 of the UKIRT (United Kingdom Infrared Telescope) Infrared Deep Sky Survey (UKIDSS) Large Area Survey. The spectral energy distributions (SED) of both subsets, with and without SDSS spectroscopy, were fitted with white dwarf models to determine the fraction of DA white dwarfs with low-mass stellar companions or dusty debris discs via the detection of excess near-infrared emission. From the spectroscopic sample we find that 2.0 per cent of white dwarfs have an excess consistent with a brown dwarf type companion, with a firm lower limit of 0.8 per cent. From the white dwarfs with photometry only, we find that 1.8 per cent are candidates for having brown dwarf companions. Similarly, both samples show that ˜1 per cent of white dwarfs are candidates for having a dusty debris disc.

Global energy and water cycle experiment (GEWEX) continental-scale international project (GCIP); reference data sets CD-ROM

USGS Publications Warehouse

Rea, Alan; Cederstrand, Joel R.

1994-01-01

The data sets on this compact disc are a compilation of several geographic reference data sets of interest to the global-change research community. The data sets were chosen with input from the Global Energy and Water Cycle Experiment (GEWEX) Continental-Scale International Project (GCIP) Data Committee and the GCIP Hydrometeorology and Atmospheric Subpanels. The data sets include: locations and periods of record for stream gages, reservoir gages, and meteorological stations; a 500-meter-resolution digital elevation model; grid-node locations for the Eta numerical weather-prediction model; and digital map data sets of geology, land use, streams, large reservoirs, average annual runoff, average annual precipitation, average annual temperature, average annual heating and cooling degree days, hydrologic units, and state and county boundaries. Also included are digital index maps for LANDSAT scenes, and for the U.S. Geological Survey 1:250,000, 1:100,000, and 1:24,000-scale map series. Most of the data sets cover the conterminous United States; the digital elevation model also includes part of southern Canada. The stream and reservoir gage and meteorological station files cover all states having area within the Mississippi River Basin plus that part of the Mississippi River Basin lying within Canada. Several data-base retrievals were processed by state, therefore many sites outside the Mississippi River Basin are included.

40 Gb/s W-band (75-110 GHz) 16-QAM radio-over-fiber signal generation and its wireless transmission.

PubMed

Kanno, Atsushi; Inagaki, Keizo; Morohashi, Isao; Sakamoto, Takahide; Kuri, Toshiaki; Hosako, Iwao; Kawanishi, Tetsuya; Yoshida, Yuki; Kitayama, Ken-ichi

2011-12-12

The generation of a 40-Gb/s 16-QAM radio-over-fiber (RoF) signal and its demodulation of the wireless signal transmitted over free space of 30 mm in W-band (75-110 GHz) is demonstrated. The 16-QAM signal is generated by a coherent polarization synthesis method using a dual-polarization QPSK modulator. A combination of the simple RoF generation and the versatile digital receiver technique is suitable for the proposed coherent optical/wireless seamless network. © 2011 Optical Society of America

UCTM2: An updated User friendly Configurable Trigger, scaler and delay Module for nuclear and particle physics

NASA Astrophysics Data System (ADS)

Bourrion, O.; Boyer, B.; Derome, L.; Pignol, G.

2016-06-01

We developed a highly integrated and versatile electronic module to equip small nuclear physics experiments and lab teaching classes: the User friendly Configurable Trigger, scaler and delay Module for nuclear and particle physics (UCTM). It is configurable through a Graphical User Interface (GUI) and provides a large number of possible trigger conditions without any Hardware Description Language (HDL) required knowledge. This new version significantly enhances the previous capabilities by providing two additional features: signal digitization and time measurements. The design, performances and a typical application are presented.

Combining monolithic zirconia crowns, digital impressioning, and regenerative cement for a predictable restorative alternative to PFM.

PubMed

Griffin, Jack D

2013-03-01

Advances in indirect esthetic materials in recent years have provided the dental profession higher levels of strength and esthetics than ever before with products like lithium disilicate and zirconium oxide. Providing excellent fit and versatile performance, and because there is no porcelain to delaminate, chip, or fracture, monolithic zirconia crowns have the potential to outperform other layered restorations such as porcelain-fused-to-metal (PFM). This review of monolithic zirconia highlights a clinical case in which all-zirconia restorations were combined with CAD/CAM technology for a successful esthetic restorative outcome.

Comparison of native porcine skin and a dermal substitute using tensiometry and digital image speckle correlation.

PubMed

Fritz, Jason R; Phillips, Brett T; Conkling, Nicole; Fourman, Mitchell; Melendez, Mark M; Bhatnagar, Divya; Simon, Marcia; Rafailovich, Miriam; Dagum, Alexander B

2012-10-01

Dermal substitutes are currently used in plastic surgery to cover various soft tissue defects caused by trauma, burns, or ablative cancer surgery. Little information is available on the biomechanical properties of these dermal substitutes after adequate incorporation as compared to normal skin. Determining parameters such as tensile strength in these skin substitutes will help us further understand their wound healing properties and potential in developing artificial tissue constructs. We hypothesize that a dermal substitute has a lower stress-strain curve and altered stress-induced deformation quantified with tensiometry and digital image speckle correlation (DISC) analysis. Two separate 5×10-cm full-thickness wounds were created on the dorsum of 3 female swine. Fibrin glue was applied before either a full-thickness skin graft (FTSG) or application of artificial dermal matrix. On day 42, cultured autologous keratinocytes were applied as a cell sheet to the wound covered with Integra. On day 56, the wounds were fully excised and fresh tissue specimens, including normal skin, were stored in a physiological solution and prepared for analysis. Rectangular samples were excised from the center of each specimen measuring 4×4×30 mm. Using a tensiometer and DISC analysis, we evaluated the tensile strength of 3 different groups of skin, namely, normal, FTSG, and Integra. There is a significant difference between the Integra specimen when compared to normal skin and FTSG. We found a minimal difference in the stress-strain curves of the latter two. Integra alone shows plastic deformation with continued stretching before ultimate midline fracture. There is significant change between the Young's moduli of the normal skin and the Integra, whereas there is little difference between the FTSG and the normal skin; DISC confirms this analysis. The normal skin and FTSG show a convergence of vectors to a linear plane, whereas Integra shows very little organization. Using 2 different methods of analysis, we have shown a dermal substitute does not display similar biomechanical properties after adequate incorporation. These major tensile strength differences are shown between normal, grafted, and Integra constructs under physiological conditions. These properties will lead to further understanding of artificial tissue and engineered constructs in laboratory and clinical applications.

Conventional versus digital radiographs for intraoperative cervical spine-level localization: a prospective time and cost analysis.

PubMed

Steinmetz, Michael P; Mroz, Thomas E; Krishnaney, Ajit; Modic, Michael

2009-12-01

In today's health-care environment, operational efficiency is intrinsic to balancing the need for increased productivity driven by rising costs and potentially decreasing reimbursement. Other operational factors kept constant, decreasing the time for a procedure can be viewed as one marker for increased efficiency. To prospectively evaluate the time and operating room efficiency differences between the two methods for intraoperative level localization. STYDY DESIGN: Prospective nonrandomized study. Prospective consecutive patients undergoing a single-level anterior cervical discectomy and fusion (ACDF) with plate and allograft. Time for performance and interpretation of intraoperative localization radiograph. This is a prospective nonrandomized study of patients treated consecutively with a single-level ACDF with allograft and plating. All the patients underwent a conventional approach to the cervical spine. After exposure, a spinal needle was placed in the exposed intervertebral disc and a radiography was performed. Either a conventional or a digital radiography was used in each case. Eighteen patients were enrolled in this study. Ten patients underwent localization with conventional radiography, whereas eight patients underwent localization with digital imaging. The mean time for conventional radiography was 823 seconds (standard deviation [SD], 159), and for digital, it was 100 seconds (SD, 34; p<.001). Current technology provides options for level localization. Digital imaging provides equally accurate information as conventional radiography in a significantly reduced amount of time. Image quality, ease or archival, and manipulation provided by digital radiography are superior to those by provided fluoroscopy. Keeping operational factors constant, decreasing the time for a procedure, and increasing the efficiency of the environment may be viewed as a surrogate for improving the cost basis for a procedure.

Crowdsourcing as a screening tool to detect clinical features of glaucomatous optic neuropathy from digital photography.

PubMed

Mitry, Danny; Peto, Tunde; Hayat, Shabina; Blows, Peter; Morgan, James; Khaw, Kay-Tee; Foster, Paul J

2015-01-01

Crowdsourcing is the process of simplifying and outsourcing numerous tasks to many untrained individuals. Our aim was to assess the performance and repeatability of crowdsourcing in the classification of normal and glaucomatous discs from optic disc images. Optic disc images (N = 127) with pre-determined disease status were selected by consensus agreement from grading experts from a large cohort study. After reading brief illustrative instructions, we requested that knowledge workers (KWs) from a crowdsourcing platform (Amazon MTurk) classified each image as normal or abnormal. Each image was classified 20 times by different KWs. Two study designs were examined to assess the effect of varying KW experience and both study designs were conducted twice for consistency. Performance was assessed by comparing the sensitivity, specificity and area under the receiver operating characteristic curve (AUC). Overall, 2,540 classifications were received in under 24 hours at minimal cost. The sensitivity ranged between 83-88% across both trials and study designs, however the specificity was poor, ranging between 35-43%. In trial 1, the highest AUC (95%CI) was 0.64(0.62-0.66) and in trial 2 it was 0.63(0.61-0.65). There were no significant differences between study design or trials conducted. Crowdsourcing represents a cost-effective method of image analysis which demonstrates good repeatability and a high sensitivity. Optimisation of variables such as reward schemes, mode of image presentation, expanded response options and incorporation of training modules should be examined to determine their effect on the accuracy and reliability of this technique in retinal image analysis.

The characterization of the distant blazar GB6 J1239+0443 from flaring and low activity periods

DOE PAGES

Pacciani, L.; Donnarumma, I.; Denney, K. D.; ...

2012-08-27

In 2008, AGILE and Fermi detected gamma-ray flaring activity from the unidentified EGRET source 3EG J1236+0457, recently associated with a flat spectrum radio quasar (GB6 J1239+0443) at z = 1.762. The optical counterpart of the gamma-ray source underwent a flux enhancement of a factor of 15–30 in six years, and of ~10 in six months. Here, we interpret this flare-up in terms of a transition from an accretion-disc-dominated emission to a synchrotron-jet-dominated one. We analysed a Sloan Digital Sky Survey (SDSS) archival optical spectrum taken during a period of low radio and optical activity of the source. We estimated themore » mass of the central black hole using the width of the C iv emission line. In our work, we have also investigated SDSS archival optical photometric data and ultraviolet GALEX observations to estimate the thermal disc emission contribution of GB6 J1239+0443. This analysis of the gamma-ray data taken during the flaring episodes indicates a flat gamma-ray spectrum, with an extension of up to 15 GeV, with no statistically relevant sign of absorption from the broad-line region, suggesting that the blazar zone is located beyond the broad-line region. Our result is confirmed by the modelling of the broad-band spectral energy distribution (well constrained by the available multiwavelength data) of the flaring activity periods and by the accretion disc luminosity and black hole mass estimated by us using archival data.« less

Macular slippage after macular hole surgery with internal limiting membrane peeling.

PubMed

Nakagomi, Tomomi; Goto, Teruhiko; Tateno, Yasushi; Oshiro, Tomohiro; Iijima, Hiroyuki

2013-12-01

To describe macular slippage toward the optic disc after macular hole surgery with internal limiting membrane (ILM) peeling. A total of 27 eyes of 27 patients with idiopathic macular hole were included in this retrospective study. The fovea-to-disc distance (FDD) was measured from digital color fundus images before and at least six months after surgery. The position of the fovea was determined as the center of the macular hole before surgery and the center of the macular pigment area after surgery. The thickness of the nasal and temporal macula was measured using spectral-domain optical coherence tomography. The difference in thickness between the nasal and temporal macula was determined as the degree of parafoveal asymmetry (PFA). The postoperative FDD was significantly shorter than the preoperative FDD: 4.00 ± 0.33 mm and 3.82 ± 0.34 mm, respectively (p < 0.0001). The mean decreased ratio of FDD was 4.68% (range, 0.38-9.24%). The appearance of the dissociated optic nerve fiber layer (DONFL) was finally found in 21 eyes (78%). The decreased FDD ratio was significantly larger in eyes with the DONFL appearance than in those without it: 5.61 ± 1.74% and 1.44 ± 1.12%, respectively (p < 0.0001). The decreased ratio of FDD was correlated with the postoperative PFA (r = 0.63, p = 0.0004). A macula in which the ILM has peeled off would slip toward the optic disc after macular hole surgery. Macular slippage can be a reasonable cause for the macular alterations such as an appearance of DONFL and changes in asymmetrical parafoveal thickness.

Spontaneous generation of bending waves in isolated Milky Way-like discs

NASA Astrophysics Data System (ADS)

Chequers, Matthew H.; Widrow, Lawrence M.

2017-12-01

We study the spontaneous generation and evolution of bending waves in N-body simulations of two isolated Milky Way-like galaxy models. The models differ by their disc-to-halo mass ratios, and hence by their susceptibility to the formation of a bar and spiral structure. Seeded from shot noise in the particle distribution, bending waves rapidly form in both models and persist for many billions of years. Waves at intermediate radii manifest as corrugated structures in vertical position and velocity that are tightly wound, morphologically leading and dominated by the m = 1 azimuthal Fourier component. A spectral analysis of the waves suggests they are a superposition of modes from two continuous branches in the Galactocentric radius-rotational frequency plane. The lower frequency branch is dominant and is responsible for the corrugated, leading and warped structure. Over time, power in this branch migrates outward, lending credence to an inside-out formation scenario for the warp. Our power spectra qualitatively agree with results from linear perturbation theory and a WKB analysis, both of which include self-gravity. Thus, we conclude that the waves in our simulations are self-gravitating and not purely kinematic. These waves are reminiscent of the wave-like pattern recently found in Galactic star counts from the Sloan Digital Sky Survey and smoothly transition to a warp near the disc's edge. Velocity measurements from Gaia data will be instrumental in testing the true wave nature of the corrugations. We also compile a list of 'minimum requirements' needed to observe bending waves in external galaxies.

Global dust attenuation in disc galaxies: strong variation with specific star formation and stellar mass, and the importance of sample selection

NASA Astrophysics Data System (ADS)

Devour, Brian M.; Bell, Eric F.

2016-06-01

We study the relative dust attenuation-inclination relation in 78 721 nearby galaxies using the axis ratio dependence of optical-near-IR colour, as measured by the Sloan Digital Sky Survey, the Two Micron All Sky Survey, and the Wide-field Infrared Survey Explorer. In order to avoid to the greatest extent possible attenuation-driven biases, we carefully select galaxies using dust attenuation-independent near- and mid-IR luminosities and colours. Relative u-band attenuation between face-on and edge-on disc galaxies along the star-forming main sequence varies from ˜0.55 mag up to ˜1.55 mag. The strength of the relative attenuation varies strongly with both specific star formation rate and galaxy luminosity (or stellar mass). The dependence of relative attenuation on luminosity is not monotonic, but rather peaks at M3.4 μm ≈ -21.5, corresponding to M* ≈ 3 × 1010 M⊙. This behaviour stands seemingly in contrast to some older studies; we show that older works failed to reliably probe to higher luminosities, and were insensitive to the decrease in attenuation with increasing luminosity for the brightest star-forming discs. Back-of-the-envelope scaling relations predict the strong variation of dust optical depth with specific star formation rate and stellar mass. More in-depth comparisons using the scaling relations to model the relative attenuation require the inclusion of star-dust geometry to reproduce the details of these variations (especially at high luminosities), highlighting the importance of these geometrical effects.

Reflex-free digital fundus photography using a simple and portable camera adaptor system. A viable alternative.

PubMed

Pirie, Chris G; Pizzirani, Stefano

2011-12-01

To describe a digital single lens reflex (dSLR) camera adaptor for posterior segment photography. A total of 30 normal canine and feline animals were imaged using a dSLR adaptor which mounts between a dSLR camera body and lens. Posterior segment viewing and imaging was performed with the aid of an indirect lens ranging from 28-90D. Coaxial illumination for viewing was provided by a single white light emitting diode (LED) within the adaptor, while illumination during exposure was provided by the pop-up flash or an accessory flash. Corneal and/or lens reflections were reduced using a pair of linear polarizers, having their azimuths perpendicular to one another. Quality high-resolution, reflection-free, digital images of the retina were obtained. Subjective image evaluation demonstrated the same amount of detail, as compared to a conventional fundus camera. A wide range of magnification(s) [1.2-4X] and/or field(s) of view [31-95 degrees, horizontal] were obtained by altering the indirect lens utilized. The described adaptor may provide an alternative to existing fundus camera systems. Quality images were obtained and the adapter proved to be versatile, portable and of low cost.

Reconstructing the past: methods and techniques for the digital restoration of fossils

PubMed Central

2016-01-01

During fossilization, the remains of extinct organisms are subjected to taphonomic and diagenetic processes. As a result, fossils show a variety of preservational artefacts, which can range from small breaks and cracks, disarticulation and fragmentation, to the loss and deformation of skeletal structures and other hard parts. Such artefacts can present a considerable problem, as the preserved morphology of fossils often forms the basis for palaeontological research. Phylogenetic and taxonomic studies, inferences on appearance, ecology and behaviour and functional analyses of fossil organisms strongly rely on morphological information. As a consequence, the restoration of fossil morphology is often a necessary prerequisite for further analyses. Facilitated by recent computational advances, virtual reconstruction and restoration techniques offer versatile tools to restore the original morphology of fossils. Different methodological steps and approaches, as well as software are outlined and reviewed here, and advantages and disadvantages are discussed. Although the complexity of the restorative processes can introduce a degree of interpretation, digitally restored fossils can provide useful morphological information and can be used to obtain functional estimates. Additionally, the digital nature of the restored models can open up possibilities for education and outreach and further research. PMID:27853548

Comparison of animal discs used in disc research to human lumbar disc: torsion mechanics and collagen content.

PubMed

Showalter, Brent L; Beckstein, Jesse C; Martin, John T; Beattie, Elizabeth E; Espinoza Orías, Alejandro A; Schaer, Thomas P; Vresilovic, Edward J; Elliott, Dawn M

2012-07-01

Experimental measurement and normalization of in vitro disc torsion mechanics and collagen content for several animal species used in intervertebral disc research and comparing these with the human disc. To aid in the selection of appropriate animal models for disc research by measuring torsional mechanical properties and collagen content. There is lack of data and variability in testing protocols for comparing animal and human disc torsion mechanics and collagen content. Intervertebral disc torsion mechanics were measured and normalized by disc height and polar moment of inertia for 11 disc types in 8 mammalian species: the calf, pig, baboon, goat, sheep, rabbit, rat, and mouse lumbar discs, and cow, rat, and mouse caudal discs. Collagen content was measured and normalized by dry weight for the same discs except the rat and the mouse. Collagen fiber stretch in torsion was calculated using an analytical model. Measured torsion parameters varied by several orders of magnitude across the different species. After geometric normalization, only the sheep and pig discs were statistically different from human discs. Fiber stretch was found to be highly dependent on the assumed initial fiber angle. The collagen content of the discs was similar, especially in the outer annulus where only the calf and goat discs were statistically different from human. Disc collagen content did not correlate with torsion mechanics. Disc torsion mechanics are comparable with human lumbar discs in 9 of 11 disc types after normalization by geometry. The normalized torsion mechanics and collagen content of the multiple animal discs presented are useful for selecting and interpreting results for animal disc models. Structural organization of the fiber angle may explain the differences that were noted between species after geometric normalization.

Information Technology and Development Series. Volume 2. Informatics and Industrial Development. Proceedings of the International Conference on Policies for Information Processing for Developing Countries Held at Dublin, Ireland on 9-13 March 1981,

DTIC Science & Technology

1982-11-01

Pihilips lIiAO i:l ()(xxsclrn prtixics, tor full -tcsr storagec onr ultra high dkrisit\\ I cad-tirtl digit al optical tiascrl discs, wiul th. fxast rctricx...activity, and hence gain full employment in other sectors of the society. The whole issue of the employment effects of informatics will be taken up later in...mini- and micro-computers and of more or less intelligent peripherals. However, this is still doubtful unless a full compre- hension of the political

LANDSAT digital data for water pollution and water quality studies in Southern Scandinavia

NASA Technical Reports Server (NTRS)

Hellden, U.; Akersten, I.

1977-01-01

Spectral diagrams, illustrating the spectral characteristics of different water types, were constructed by means of simple statistical analysis of the various reflectance properties of water areas in Southern Scandinavia as registered by LANDSAT-1. There were indications that water whose spectral reproduction is dominated by chlorophyllous matter (phytoplankton) can be distinguished from water dominated by nonchlorophyllous matter. Differences between lakes, as well as the patchiness of individual lakes, concerning secchi disc transparency could be visualized after classification and reproduction in black and white and in color by means of line printer, calcomp plotter (CRT), and ink jet plotter respectively.

Biological Signal Processing with a Genetic Toggle Switch

PubMed Central

Hillenbrand, Patrick; Fritz, Georg; Gerland, Ulrich

2013-01-01

Complex gene regulation requires responses that depend not only on the current levels of input signals but also on signals received in the past. In digital electronics, logic circuits with this property are referred to as sequential logic, in contrast to the simpler combinatorial logic without such internal memory. In molecular biology, memory is implemented in various forms such as biochemical modification of proteins or multistable gene circuits, but the design of the regulatory interface, which processes the input signals and the memory content, is often not well understood. Here, we explore design constraints for such regulatory interfaces using coarse-grained nonlinear models and stochastic simulations of detailed biochemical reaction networks. We test different designs for biological analogs of the most versatile memory element in digital electronics, the JK-latch. Our analysis shows that simple protein-protein interactions and protein-DNA binding are sufficient, in principle, to implement genetic circuits with the capabilities of a JK-latch. However, it also exposes fundamental limitations to its reliability, due to the fact that biological signal processing is asynchronous, in contrast to most digital electronics systems that feature a central clock to orchestrate the timing of all operations. We describe a seemingly natural way to improve the reliability by invoking the master-slave concept from digital electronics design. This concept could be useful to interpret the design of natural regulatory circuits, and for the design of synthetic biological systems. PMID:23874595

Biaxial deformation in high purity aluminum

DOE PAGES

Livescu, V.; Bingert, J. F.; Liu, C.; ...

2015-09-25

The convergence of multiple characterization tools has been applied to investigate the relationship of microstructure on damage evolution in high purity aluminum. The extremely coarse grain size of the disc-shaped sample provided a quasi-two dimensional structure from which the location of surface-measured features could be inferred. In particular, the role of pre-existing defects on damage growth was accessible due to the presence of casting porosity in the aluminum. Micro tomography, electron backscatter diffraction, and digital image correlation were applied to interrogate the sample in three dimensions. Recently micro-bulge testing apparatus was used to deform the pre-characterized disc of aluminum inmore » biaxial tension, and related analysis techniques were applied to map local strain fields. Subsequent post-mortem characterization of the failed sample was performed to correlate structure to damaged regions. We determined that strain localization and associated damage was most strongly correlated with grain boundary intersections and plastic anisotropy gradients between grains. Pre-existing voids played less of an apparent role than was perhaps initially expected. Finally, these combined techniques provide insight to the mechanism of damage initiation, propagation, and failure, along with a test bed for predictive damage models incorporating anisotropic microstructural effects.« less

Recovering Nimbus era Observations at the NASA GES DISC

NASA Astrophysics Data System (ADS)

Meyer, D. J.; Johnson, J. E.; Esfandiari, A. E.; Zamkoff, E. B.; Al-Jazrawi, A. F.; Gerasimov, I. V.; Alcott, G. T.

2017-12-01

Between 1964 and 1978, NASA launched a series of seven Nimbus meteorological satellites which provided Earth observations for 30 years. These satellites, carrying a total of 33 instruments to observe the Earth at visible, infrared, ultraviolet, and microwave wavelengths, revolutionized weather forecasting, provided early observations of ocean color and atmospheric ozone, and prototyped location-based search and rescue capabilities. The Nimbus series paved the way for a number of currently operational systems such as the EOS Terra, Aqua and Aura platforms.The original data archive included both magnetic tapes and film media. These media are well past their expected end of life, placing at risk valuable data that are critical to extending the history of Earth observations back in time. GES DISC has been incorporating these data into a modern online archive by recovering the digital data files from the tapes, and scanning images of the data from film strips. The original data products were written on obsolete hardware systems in outdated file formats, and in the absence of metadata standards at that time, were often written in proprietary file structures. Through a tedious and laborious process, oft-corrupted data are recovered, and incomplete metadata and documentation are reconstructed.

Implementation of a departmental picture archiving and communication system: a productivity and cost analysis.

PubMed

Macyszyn, Luke; Lega, Brad; Bohman, Leif-Erik; Latefi, Ahmad; Smith, Michelle J; Malhotra, Neil R; Welch, William; Grady, Sean M

2013-09-01

Digital radiology enhances productivity and results in long-term cost savings. However, the viewing, storage, and sharing of outside imaging studies on compact discs at ambulatory offices and hospitals pose a number of unique challenges to a surgeon's efficiency and clinical workflow. To improve the efficiency and clinical workflow of an academic neurosurgical practice when evaluating patients with outside radiological studies. Open-source software and commercial hardware were used to design and implement a departmental picture archiving and communications system (PACS). The implementation of a departmental PACS system significantly improved productivity and enhanced collaboration in a variety of clinical settings. Using published data on the rate of information technology problems associated with outside studies on compact discs, this system produced a cost savings ranging from $6250 to $33600 and from $43200 to $72000 for 2 cohorts, urgent transfer and spine clinic patients, respectively, therefore justifying the costs of the system in less than a year. The implementation of a departmental PACS system using open-source software is straightforward and cost-effective and results in significant gains in surgeon productivity when evaluating patients with outside imaging studies.

Quantitative evaluation of reduction of plaque-like hard exudates in diabetic macular edema after intravitreal triamcinolone injection.

PubMed

Cekiç, Osman; Bardak, Yavuz; Tiğ, U Sahin; Yildizoğlu, Uzeyir; Bardak, Handan

2008-04-01

To describe a new method of quantifying the amount of plaque-like hard exudates after intravitreal triamcinolone acetonide injection in diabetic macular edema. This study included 22 eyes of 14 patients (mean age, 63 years) with chronic diabetic macular edema and plaque-like hard exudates. The patients were injected with a single dose of 4 mg intravitreal triamcinolone acetonide. The optic disc size as relative size unit was taken to quantify the hard exudates: Total areas of exudates and the optic nerve head were computed from fundus pictures with a digital analysis program on magnified images. The former was divided by the latter, and the results were expressed as a percentage value. The ratio was used to track improvements in a given eye over 6 months. Average ratio of hard exudates to optic nerve head area reduced to 81% of its initial value at 1 month (P=0.007), to 54% at 3 months (P<0.001) and to 41% at 6 months (P<0.001). The new method allowed detection of a significant reduction of ratio of hard exudates to optic disc area of diabetic plaque-like hard exudates following 4 mg intravitreal triamcinolone.

Development of the new trigger for VANDLE neutron detector

NASA Astrophysics Data System (ADS)

Hasse, Adam; Taylor, Steven; Daugherty, Hadyn; Grzywacz, Robert

2014-09-01

Beta-delayed neutron emission (βn) is the dominant decay channel for the majority of very neutron-rich nuclei. In order to study these decays a new detector system called the Versatile Array of Neutron Detectors at Low Energy (VANDLE) was constructed. A critical part of this neutron time of flight detector is a trigger unit. This trigger is sensitive to electron from beta decay down to very low energies, insensitive to gamma rays and have a good timing performance, better than 1 ns. In order to satisfy these condition, we have developed a new system, which utilizes plastic scintillator but uses recently developed light readout technique, based on the so called Silicon Photomultiplier, manufactured by Sensl. New system has been developed and performance tested using digital data acquisition system at the University of Tennessee and will be utilized in future experiments involving VANDLE. Beta-delayed neutron emission (βn) is the dominant decay channel for the majority of very neutron-rich nuclei. In order to study these decays a new detector system called the Versatile Array of Neutron Detectors at Low Energy (VANDLE) was constructed. A critical part of this neutron time of flight detector is a trigger unit. This trigger is sensitive to electron from beta decay down to very low energies, insensitive to gamma rays and have a good timing performance, better than 1 ns. In order to satisfy these condition, we have developed a new system, which utilizes plastic scintillator but uses recently developed light readout technique, based on the so called Silicon Photomultiplier, manufactured by Sensl. New system has been developed and performance tested using digital data acquisition system at the University of Tennessee and will be utilized in future experiments involving VANDLE. Department of Physics and Astronomy, University of Tennessee, Knoxville, USA.

[Research progress of intervertebral disc endogenous stem cells for intervertebral disc regeneration].

PubMed

Liang, Hang; Deng, Xiangyu; Shao, Zengwu

2017-10-01

To summarize the research progress of intervertebral disc endogenous stem cells for intervertebral disc regeneration and deduce the therapeutic potential of endogenous repair for intervertebral disc degeneration. The original articles about intervertebral disc endogenous stem cells for intervertebral disc regeneration were extensively reviewed; the reparative potential in vivo and the extraction and identification in vitro of intervertebral disc endogenous stem cells were analyzed; the prospect of endogenous stem cells for intervertebral disc regeneration was predicted. Stem cell niche present in the intervertebral discs, from which stem cells migrate to injured tissues and contribute to tissues regeneration under certain specific microenvironment. Moreover, the migration of stem cells is regulated by chemokines system. Tissue specific progenitor cells have been identified and successfully extracted and isolated. The findings provide the basis for biological therapy of intervertebral disc endogenous stem cells. Intervertebral disc endogenous stem cells play a crucial role in intervertebral disc regeneration. Therapeutic strategy of intervertebral disc endogenous stem cells is proven to be a promising biological approach for intervertebral disc regeneration.

Astronomy Legacy Project - Pisgah Astronomical Research Institute

NASA Astrophysics Data System (ADS)

Barker, Thurburn; Castelaz, Michael W.; Rottler, Lee; Cline, J. Donald

2016-01-01

Pisgah Astronomical Research Institute (PARI) is a not-for-profit public foundation in North Carolina dedicated to providing hands-on educational and research opportunities for a broad cross-section of users in science, technology, engineering and math (STEM) disciplines. In November 2007 a Workshop on a National Plan for Preserving Astronomical Photographic Data (2009ASPC,410,33O, Osborn, W. & Robbins, L) was held at PARI. The result was the establishment of the Astronomical Photographic Data Archive (APDA) at PARI. In late 2013 PARI began ALP (Astronomy Legacy Project). ALP's purpose is to digitize an extensive set of twentieth century photographic astronomical data housed in APDA. Because of the wide range of types of plates, plate dimensions and emulsions found among the 40+ collections, plate digitization will require a versatile set of scanners and digitizing instruments. Internet crowdfunding was used to assist in the purchase of additional digitization equipment that were described at AstroPlate2014 Plate Preservation Workshop (www.astroplate.cz) held in Prague, CZ, March, 2014. Equipment purchased included an Epson Expression 11000XL scanner and two Nikon D800E cameras. These digital instruments will compliment a STScI GAMMA scanner now located in APDA. GAMMA will be adapted to use an electroluminescence light source and a digital camera with a telecentric lens to achieve high-speed high-resolution scanning. The 1μm precision XY stage of GAMMA will allow very precise positioning of the plate stage. Multiple overlapping CCD images of small sections of each plate, tiles, will be combined using a photo-mosaic process similar to one used in Harvard's DASCH project. Implementation of a software pipeline for the creation of a SQL database containing plate images and metadata will be based upon APPLAUSE as described by Tuvikene at AstroPlate2014 (www.astroplate.cz/programs/).

Possible costs associated with investigating and mitigating geologic hazards in rural areas of western San Mateo County, California with a section on using the USGS website to determine the cost of developing property for residences in rural parts of San Mateo County, California

USGS Publications Warehouse

Brabb, Earl E.; Roberts, Sebastian; Cotton, William R.; Kropp, Alan L.; Wright, Robert H.; Zinn, Erik N.; Digital database by Roberts, Sebastian; Mills, Suzanne K.; Barnes, Jason B.; Marsolek, Joanna E.

2000-01-01

This publication consists of a digital map database on a geohazards web site, http://kaibab.wr.usgs.gov/geohazweb/intro.htm, this text, and 43 digital map images available for downloading at this site. The report is stored as several digital files, in ARC export (uncompressed) format for the database, and Postscript and PDF formats for the map images. Several of the source data layers for the images have already been released in other publications by the USGS and are available for downloading on the Internet. These source layers are not included in this digital database, but rather a reference is given for the web site where the data can be found in digital format. The exported ARC coverages and grids lie in UTM zone 10 projection. The pamphlet, which only describes the content and character of the digital map database, is included as Postscript, PDF, and ASCII text files and is also available on paper as USGS Open-File Report 00-127. The full versatility of the spatial database is realized by importing the ARC export files into ARC/INFO or an equivalent GIS. Other GIS packages, including MapInfo and ARCVIEW, can also use the ARC export files. The Postscript map image can be used for viewing or plotting in computer systems with sufficient capacity, and the considerably smaller PDF image files can be viewed or plotted in full or in part from Adobe ACROBAT software running on Macintosh, PC, or UNIX platforms.

Comparison of Animal Discs Used in Disc Research to Human Lumbar Disc: Torsion Mechanics and Collagen Content

PubMed Central

Showalter, Brent L.; Beckstein, Jesse C.; Martin, John T.; Beattie, Elizabeth E.; Orías, Alejandro A. Espinoza; Schaer, Thomas P.; Vresilovic, Edward J.; Elliott, Dawn M.

2012-01-01

Study Design Experimental measurement and normalization of in vitro disc torsion mechanics and collagen content for several animal species used in intervertebral disc research and comparing these to the human disc. Objective To aid in the selection of appropriate animal models for disc research by measuring torsional mechanical properties and collagen content. Summary of Background Data There is lack of data and variability in testing protocols for comparing animal and human disc torsion mechanics and collagen content. Methods Intervertebral disc torsion mechanics were measured and normalized by disc height and polar moment of inertia for 11 disc types in 8 mammalian species: the calf, pig, baboon, goat, sheep, rabbit, rat, and mouse lumbar, and cow, rat, and mouse caudal. Collagen content was measured and normalized by dry weight for the same discs except the rat and mouse. Collagen fiber stretch in torsion was calculated using an analytical model. Results Measured torsion parameters varied by several orders of magnitude across the different species. After geometric normalization, only the sheep and pig discs were statistically different from human. Fiber stretch was found to be highly dependent on the assumed initial fiber angle. The collagen content of the discs was similar, especially in the outer annulus where only the calf and goat discs were statistically different from human. Disc collagen content did not correlate with torsion mechanics. Conclusion Disc torsion mechanics are comparable to human lumbar discs in 9 of 11 disc types after normalization by geometry. The normalized torsion mechanics and collagen content of the multiple animal discs presented is useful for selecting and interpreting results for animal models of the disc. Structural composition of the disc, such as initial fiber angle, may explain the differences that were noted between species after geometric normalization. PMID:22333953

A simple and versatile phase detector for heterodyne interferometers

NASA Astrophysics Data System (ADS)

Mlynek, A.; Faugel, H.; Eixenberger, H.; Pautasso, G.; Sellmair, G.

2017-02-01

The measurement of the relative phase of two sinusoidal electrical signals is a frequently encountered task in heterodyne interferometry, but also occurs in many other applications. Especially in interferometry, multi-radian detectors are often required, which track the temporal evolution of the phase difference and are able to register phase changes that exceed 2π. While a large variety of solutions to this problem is already known, we present an alternative approach, which pre-processes the signals with simple analog circuitry and digitizes two resulting voltages with an analog-to-digital converter (ADC), whose sampling frequency can be far below the frequency of the sinusoidal signals. Phase reconstruction is finally carried out by software. The main advantage of this approach is its simplicity, using only few low-cost hardware components and a standard 2-channel ADC with low performance requirements. We present an application on the two-color interferometer of the ASDEX Upgrade tokamak, where the relative phase of 40 MHz sinusoids is measured.

Integrated digital flight-control system for the space shuttle orbiter

NASA Technical Reports Server (NTRS)

1973-01-01

The integrated digital flight control system is presented which provides rotational and translational control of the space shuttle orbiter in all phases of flight: from launch ascent through orbit to entry and touchdown, and during powered horizontal flights. The program provides a versatile control system structure while maintaining uniform communications with other programs, sensors, and control effectors by using an executive routine/functional subroutine format. The program reads all external variables at a single point, copies them into its dedicated storage, and then calls the required subroutines in the proper sequence. As a result, the flight control program is largely independent of other programs in the GN&C computer complex and is equally insensitive to the characteristics of the processor configuration. The integrated structure of the control system and the DFCS executive routine which embodies that structure are described along with the input and output. The specific estimation and control algorithms used in the various mission phases are given.

Video image processor on the Spacelab 2 Solar Optical Universal Polarimeter /SL2 SOUP/

NASA Technical Reports Server (NTRS)

Lindgren, R. W.; Tarbell, T. D.

1981-01-01

The SOUP instrument is designed to obtain diffraction-limited digital images of the sun with high photometric accuracy. The Video Processor originated from the requirement to provide onboard real-time image processing, both to reduce the telemetry rate and to provide meaningful video displays of scientific data to the payload crew. This original concept has evolved into a versatile digital processing system with a multitude of other uses in the SOUP program. The central element in the Video Processor design is a 16-bit central processing unit based on 2900 family bipolar bit-slice devices. All arithmetic, logical and I/O operations are under control of microprograms, stored in programmable read-only memory and initiated by commands from the LSI-11. Several functions of the Video Processor are described, including interface to the High Rate Multiplexer downlink, cosmetic and scientific data processing, scan conversion for crew displays, focus and exposure testing, and use as ground support equipment.

A versatile pipeline for the multi-scale digital reconstruction and quantitative analysis of 3D tissue architecture

PubMed Central

Morales-Navarrete, Hernán; Segovia-Miranda, Fabián; Klukowski, Piotr; Meyer, Kirstin; Nonaka, Hidenori; Marsico, Giovanni; Chernykh, Mikhail; Kalaidzidis, Alexander; Zerial, Marino; Kalaidzidis, Yannis

2015-01-01

A prerequisite for the systems biology analysis of tissues is an accurate digital three-dimensional reconstruction of tissue structure based on images of markers covering multiple scales. Here, we designed a flexible pipeline for the multi-scale reconstruction and quantitative morphological analysis of tissue architecture from microscopy images. Our pipeline includes newly developed algorithms that address specific challenges of thick dense tissue reconstruction. Our implementation allows for a flexible workflow, scalable to high-throughput analysis and applicable to various mammalian tissues. We applied it to the analysis of liver tissue and extracted quantitative parameters of sinusoids, bile canaliculi and cell shapes, recognizing different liver cell types with high accuracy. Using our platform, we uncovered an unexpected zonation pattern of hepatocytes with different size, nuclei and DNA content, thus revealing new features of liver tissue organization. The pipeline also proved effective to analyse lung and kidney tissue, demonstrating its generality and robustness. DOI: http://dx.doi.org/10.7554/eLife.11214.001 PMID:26673893

Digital holographic microscopy long-term and real-time monitoring of cell division and changes under simulated zero gravity.

PubMed

Pan, Feng; Liu, Shuo; Wang, Zhe; Shang, Peng; Xiao, Wen

2012-05-07

The long-term and real-time monitoring the cell division and changes of osteoblasts under simulated zero gravity condition were succeed by combing a digital holographic microscopy (DHM) with a superconducting magnet (SM). The SM could generate different magnetic force fields in a cylindrical cavity, where the gravitational force of biological samples could be canceled at a special gravity position by a high magnetic force. Therefore the specimens were levitated and in a simulated zero gravity environment. The DHM was modified to fit with SM by using single mode optical fibers and a vertically-configured jig designed to hold specimens and integrate optical device in the magnet's bore. The results presented the first-phase images of living cells undergoing dynamic divisions and changes under simulated zero gravity environment for a period of 10 hours. The experiments demonstrated that the SM-compatible DHM setup could provide a highly efficient and versatile method for research on the effects of microgravity on biological samples.

Electromagnetic versus Lense-Thirring alignment of black hole accretion discs

NASA Astrophysics Data System (ADS)

Polko, Peter; McKinney, Jonathan C.

2017-01-01

Accretion discs and black holes (BHs) have angular momenta that are generally misaligned, which can lead to warped discs and bends in any jets produced. We examine whether a disc that is misaligned at large radii can be aligned more efficiently by the torque of a Blandford-Znajek (BZ) jet than by Lense-Thirring (LT) precession. To obtain a strong result, we will assume that these torques maximally align the disc, rather than cause precession, or disc tearing. We consider several disc states that include radiatively inefficient thick discs, radiatively efficient thin discs, and super-Eddington accretion discs. The magnetic field strength of the BZ jet is chosen as either from standard equipartition arguments or from magnetically arrested disc (MAD) simulations. We show that standard thin accretion discs can reach spin-disc alignment out to large radii long before LT would play a role, due to the slow infall time that gives even a weak BZ jet time to align the disc. We show that geometrically thick radiatively inefficient discs and super-Eddington discs in the MAD state reach spin-disc alignment near the BH when density profiles are shallow as in magnetohydrodynamical simulations, while the BZ jet aligns discs with steep density profiles (as in advection-dominated accretion flows) out to larger radii. Our results imply that the BZ jet torque should affect the cosmological evolution of BH spin magnitude and direction, spin measurements in active galactic nuclei and X-ray binaries, and the interpretations for Event Horizon Telescope observations of discs or jets in strong-field gravity regimes.

Comparative study between the radiopacity levels of high viscosity and of flowable composite resins, using digital imaging.

PubMed

Arita, Emiko S; Silveira, Gilson P; Cortes, Arthur R; Brucoli, Henrique C

2012-01-01

The development of countless types and trends of high viscosite and flowable composite resins, with different physical and chemical properties applicable to their broad use in dental clinics calls for further studies regarding their radiopacity level. The aim of this study was to evaluate the radiopacity levels of high viscosity and the flowable composite resins, using digital imaging. 96 composite resin discs 5 mm in diameter and 3 mm thick were radiographed and analyzed. The image acquisition system used was the Digora® Phosphor Storage System and the images were analyzed with the Digora software for Windows. The exposure conditions were: 70 kVp, 8 mA, and 0.2 s. The focal distance was 40 cm. The image densities were obtained with the pixel values of the materials in the digital image. Most of the high viscosity composite resins presented higher radiopacity levels than the flowable composite resins, with statistically significant differences between the trends and groups analyzed (P < 0.05). Among the high viscosity composite resins, Tetric®Ceram presented the highest radiopacity levels and Glacier® presented the lowest. Among the flowable composite resins, Tetric®Flow presented the highest radiopacity levels and Wave® presented the lowest.

Change in area of geographic atrophy in the Age-Related Eye Disease Study: AREDS report number 26.

PubMed

Lindblad, Anne S; Lloyd, Patricia C; Clemons, Traci E; Gensler, Gary R; Ferris, Frederick L; Klein, Michael L; Armstrong, Jane R

2009-09-01

To characterize progression of geographic atrophy (GA) associated with age-related macular degeneration in AREDS as measured by digitized fundus photographs. Fundus photographs from 181 of 4757 AREDS participants with a GA area of at least 0.5 disc areas at baseline or from participants who developed bilateral GA during follow-up were scanned, digitized, and evaluated longitudinally. Geographic atrophy area was determined using planimetry. Rates of progression from noncentral to central GA and of vision loss following development of central GA included the entire AREDS cohort. Median initial lesion size was 4.3 mm(2). Average change in digital area of GA from baseline was 2.03 mm(2) (standard error of the mean, 0.24 mm(2)) at 1 year, 3.78 mm(2) (0.24 mm(2)) at 2 years, 5.93 mm(2) (0.34 mm(2)) at 3 years, and 1.78 mm(2) (0.086 mm(2)) per year overall. Median time to developing central GA after any GA diagnosis was 2.5 years (95% confidence interval, 2.0-3.0). Average visual acuity decreased by 3.7 letters at first documentation of central GA, and by 22 letters at year 5. Growth of GA area can be reliably measured using standard fundus photographs that are digitized and subsequently graded at a reading center. Development of GA is associated with subsequent further growth of GA, development of central GA, and loss in central vision.

A flexible continuous-variable QKD system using off-the-shelf components

NASA Astrophysics Data System (ADS)

Comandar, Lucian C.; Brunner, Hans H.; Bettelli, Stefano; Fung, Fred; Karinou, Fotini; Hillerkuss, David; Mikroulis, Spiros; Wang, Dawei; Kuschnerov, Maxim; Xie, Changsong; Poppe, Andreas; Peev, Momtchil

2017-10-01

We present the development of a robust and versatile CV-QKD architecture based on commercially available optical and electronic components. The system uses a pilot tone for phase synchronization with a local oscillator, as well as local feedback loops to mitigate frequency and polarization drifts. Transmit and receive-side digital signal processing is performed fully in software, allowing for rapid protocol reconfiguration. The quantum link is complemented with a software stack for secure-key processing, key storage and encrypted communication. All these features allow for the system to be at the same time a prototype for a future commercial product and a research platform.

Vortex Airy beams directly generated via liquid crystal q-Airy-plates

NASA Astrophysics Data System (ADS)

Wei, Bing-Yan; Liu, Sheng; Chen, Peng; Qi, Shu-Xia; Zhang, Yi; Hu, Wei; Lu, Yan-Qing; Zhao, Jian-Lin

2018-03-01

Liquid crystal q-Airy-plates with director distributions integrated by q-plates and polarization Airy masks are proposed and demonstrated via the photoalignment technique. Single/dual vortex Airy beams of opposite topological charges and orthogonal circular polarizations are directly generated with polarization-controllable characteristic. The singular phase of the vortex part is verified by both astigmatic transformation and digital holography. The trajectory of vortex Airy beams is investigated, manifesting separate propagation dynamics of optical vortices and Airy beams. Meanwhile, Airy beams still keep their intrinsic transverse acceleration, self-healing, and nondiffraction features. This work provides a versatile candidate for generating high-quality vortex Airy beams.

Determination of piezo-optic coefficients of crystals by means of four-point bending.

PubMed

Krupych, Oleg; Savaryn, Viktoriya; Krupych, Andriy; Klymiv, Ivan; Vlokh, Rostyslav

2013-06-10

A technique developed recently for determining piezo-optic coefficients (POCs) of isotropic optical media, which represents a combination of digital imaging laser interferometry and a classical four-point bending method, is generalized and applied to a single-crystalline anisotropic material. The peculiarities of measuring procedures and data processing for the case of optically uniaxial crystals are described in detail. The capabilities of the technique are tested on the example of canonical nonlinear optical crystal LiNbO3. The high precision achieved in determination of the POCs for isotropic and anisotropic materials testifies that the technique should be both versatile and reliable.

Physics teaching by infrared remote sensing of vegetation

NASA Astrophysics Data System (ADS)

Schüttler, Tobias; Maman, Shimrit; Girwidz, Raimund

2018-05-01

Context- and project-based teaching has proven to foster different affective and cognitive aspects of learning. As a versatile and multidisciplinary scientific research area with diverse applications for everyday life, satellite remote sensing is an interesting context for physics education. In this paper we give a brief overview of satellite remote sensing of vegetation and how to obtain your own, individual infrared remote sensing data with affordable converted digital cameras. This novel technique provides the opportunity to conduct individual remote sensing measurement projects with students in their respective environment. The data can be compared to real satellite data and is of sufficient accuracy for educational purposes.

High surface plasmon resonance sensitivity enabled by optical disks.

PubMed

Dou, Xuan; Phillips, Blayne M; Chung, Pei-Yu; Jiang, Peng

2012-09-01

We report a systematic, experimental, and theoretical investigation on the surface plasmon resonance (SPR) sensing using optical disks with different track pitches, including Blu-ray disk (BD), digital versatile disk (DVD), and compact disk (CD). Optical reflection measurements indicate that CD and DVD exhibit much higher SPR sensitivity than BD. Both experiments and finite-difference time-domain simulations reveal that the SPR sensitivity is significantly affected by the diffraction order of the SPR peaks and higher diffraction order results in lower sensitivity. Numerical simulations also show that very high sensitivity (∼1600  nm per refractive index unit) is achievable by CDs.

Kinematic Evaluation of Association between Disc Bulge Migration, Lumbar Segmental Mobility, and Disc Degeneration in the Lumbar Spine Using Positional Magnetic Resonance Imaging

PubMed Central

Hu, Jonathan K.; Morishita, Yuichiro; Montgomery, Scott R.; Hymanson, Henry; Taghavi, Cyrus E.; Do, Duc; Wang, Jeff C.

2011-01-01

Degenerative disc disease and disc bulge in the lumbar spine are common sources of lower back pain. Little is known regarding disc bulge migration and lumbar segmental mobility as the lumbar spine moves from flexion to extension. In this study, 329 symptomatic (low back pain with or without neurological symptoms) patients with an average age of 43.5 years with varying degrees of disc degeneration were examined to characterize the kinematics of the lumbar intervertebral discs through flexion, neutral, and extension weight-bearing positions. In this population, disc bulge migration associated with dynamic motion of the lumbar spine significantly increased with increased grade of disk degeneration. Although no obvious trends relating the migration of disc bulge and angular segmental mobility were seen, translational segmental mobility tended to increase with disc bulge migration in all of the degenerative disc states. It appears that many factors, both static (intervertebral disc degeneration or disc height) and dynamic (lumbar segmental mobility), affect the mechanisms of lumbar disc bulge migration. PMID:24353937

Economic and environmental benefits of reducing standby power lossin DVD/VCD players and copiers in China

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

Lin, Jiang; Li, Tienan; Li, Aizhen

With the popularization of household electrical appliances and the rapid development of office automation and networking, a huge number of consumer electronic devices, computers, copiers, and fax machines have been put into use in China over the last two decades. These products almost all use a certain amount of standby power--the power that is consumed when a device is connected but not performing its primary function. The rapid growth of standby energy consumption due to these products--and the consequent environmental problems--has attracted more and more attentions from researchers and from many government and international agencies. Numerous countries have developed policiesmore » and measures to restrict and reduce standby energy consumption (US EPA, 2004, IEA, 2001, and GEEA, 2004). However, standby energy consumption is still a new concept for Chinese consumers and the phenomenon of ''unconscious waste of energy'' is still very common in the people's daily life and work. With the goal of reducing China's standby energy consumption, China Certification Center for Energy Conservation Products (CECP) and the Lawrence Berkeley National Laboratory (LBNL) have, under the sponsorship of the Energy Foundation (EF), entered into a collaboration to develop technical requirements for CECP's labeling program for consumer electronics and office equipment. These technical requirements will be used to qualify products for CECP's energy efficiency endorsement label in China. In the phase I of this collaborative project, CECP and LBNL conducted technical and economic research on televisions and printers in China. Based on the results of this research, CECP developed specifications for, and carried out corresponding energy conservation certifications for these two products. CECP's standby power certification program has made impressive gains in China. Leading manufacturers, such as Haier, Hesons, TCL, Chuangwei, Lenovo, EPSON, Fujitsu, and Brother have participated in CECP's certification activities. Media events organized by CECP have greatly improved the country's awareness of standby power loss. Reducing standby power loss has been formally incorporated into China's energy efficiency policy portfolio and in China's collaboration with the international community on the subject of energy efficiency (IEA, 2001). In phase II of the program, CECP's main task was to assess the market for DVD/VCD (Digital Versatile/Video Disc and Video Compact Disc) players and copiers to analyze the economic and technical benefits of energy conservation potential, and to develop technical specifications for DVD/VCD players and copiers, with technical assistance from LBNL. Having built on the success of Phase I, CECP paid great attention to the appraisal of market conditions and the economic and environmental benefits of reducing standby power loss in DVD/VCD players and copiers, and solicited inputs from stakeholders before finalizing the product certification requirements. This paper summarizes the expected energy conservation and environmental benefits due to the implementation of certification programs for DVD/VCD players and copiers in China.« less

Imaginal Disc Abnormalities in Lethal Mutants of Drosophila

PubMed Central

Shearn, Allen; Rice, Thomas; Garen, Alan; Gehring, Walter

1971-01-01

Late lethal mutants of Drosophila melanogaster, dying after the larval stage of development, were isolated. The homozygous mutant larvae were examined for abnormal imaginal disc morphology, and the discs were injected into normal larval hosts to test their capacities to differentiate into adult structures. In about half of the mutants analyzed, disc abnormalities were found. Included among the abnormalities were missing discs, small discs incapable of differentiating, morphologically normal discs with limited capacities for differentiation, and discs with homeotic transformations. In some mutants all discs were affected, and in others only certain discs. The most extreme abnormal phenotype is a class of “discless” mutants. The viability of these mutant larvae indicates that the discs are essential only for the development of an adult and not of a larva. The late lethals are therefore a major source of mutants for studying the genetic control of disc formation. Images PMID:5002822

Intermediate mass black holes in AGN discs - I. Production and growth

NASA Astrophysics Data System (ADS)

McKernan, B.; Ford, K. E. S.; Lyra, W.; Perets, H. B.

2012-09-01

Here we propose a mechanism for efficiently growing intermediate mass black holes (IMBH) in discs around supermassive black holes. Stellar mass objects can efficiently agglomerate when facilitated by the gas disc. Stars, compact objects and binaries can migrate, accrete and merge within discs around supermassive black holes. While dynamical heating by cusp stars excites the velocity dispersion of nuclear cluster objects (NCOs) in the disc, gas in the disc damps NCO orbits. If gas damping dominates, NCOs remain in the disc with circularized orbits and large collision cross-sections. IMBH seeds can grow extremely rapidly by collisions with disc NCOs at low relative velocities, allowing for super-Eddington growth rates. Once an IMBH seed has cleared out its feeding zone of disc NCOs, growth of IMBH seeds can become dominated by gas accretion from the active galactic nucleus (AGN) disc. However, the IMBH can migrate in the disc and expand its feeding zone, permitting a super-Eddington accretion rate to continue. Growth of IMBH seeds via NCO collisions is enhanced by a pile-up of migrators. We highlight the remarkable parallel between the growth of IMBH in AGN discs with models of giant planet growth in protoplanetary discs. If an IMBH becomes massive enough it can open a gap in the AGN disc. IMBH migration in AGN discs may stall, allowing them to survive the end of the AGN phase and remain in galactic nuclei. Our proposed mechanisms should be more efficient at growing IMBH in AGN discs than the standard model of IMBH growth in stellar clusters. Dynamical heating of disc NCOs by cusp stars is transferred to the gas in an AGN disc helping to maintain the outer disc against gravitational instability. Model predictions, observational constraints and implications are discussed in a companion paper (Paper II).

Constraining the Galactic structure parameters with the XSTPS-GAC and SDSS photometric surveys

NASA Astrophysics Data System (ADS)

Chen, B.-Q.; Liu, X.-W.; Yuan, H.-B.; Robin, A. C.; Huang, Y.; Xiang, M.-S.; Wang, C.; Ren, J.-J.; Tian, Z.-J.; Zhang, H.-W.

2017-01-01

Photometric data from the Xuyi Schmidt Telescope Photometric Survey of the Galactic Anticentre (XSTPS-GAC) and the Sloan Digital Sky Survey (SDSS) are used to derive the global structure parameters of the smooth components of the Milky Way. The data, which cover nearly 11 000 deg2 sky area and the full range of Galactic latitude, allow us to construct a globally representative Galactic model. The number density distribution of Galactic halo stars is fitted with an oblate spheroid that decays by power law. The best fitting yields an axis ratio and a power-law index κ = 0.65 and p = 2.79, respectively. The r-band differential star counts of three dwarf samples are then fitted with a Galactic model. The best-fitting model yielded by a Markov Chain Monte Carlo analysis has thin and thick disc scale heights and lengths of H1 = 322 pc and L1 = 2343 pc, H2 = 794 pc and L2 = 3638 pc, a local thick-to-thin disc density ratio of f2 = 11 per cent, and a local density ratio of the oblate halo to the thin disc of fh = 0.16 per cent. The measured star count distribution, which is in good agreement with the above model for most of the sky area, shows a number of statistically significant large-scale overdensities, including some of the previously known substructures, such as the Virgo overdensity and the so-called `north near structure', and a new feature between 150° < l < 240° and -1° < b < -5°, at an estimated distance between 1.0 and 1.5 kpc. The Galactic North-South asymmetry in the anticentre is even stronger than previously thought.

Influence of abutment material and luting cements color on the final color of all ceramics.

PubMed

Dede, Dogu Ömür; Armaganci, Arzu; Ceylan, Gözlem; Cankaya, Soner; Celik, Ersan

2013-11-01

The purpose of this study is to evaluate the effects of different abutment materials and luting cements color on the final color of implant-supported all-ceramic restorations. Ten A2 shade IPS e.max Press disc shape all-ceramic specimens were prepared (11 × 1.5 mm). Three different shades (translucent, universal and white opaque) of disc shape luting cement specimens were prepared (11 × 0.2 mm). Three different (zirconium, gold-palladium and titanium) implant abutments and one composite resin disc shape background specimen were prepared at 11 mm diameter and appropriate thicknesses. All ceramic specimens colors were measured with each background and luting cement samples on a teflon mold. A digital spectrophotometer used for measurements and data recorded as CIE L*a*b* color co-ordinates. An optical fluid applied on to the samples to provide a good optical connection and measurements on the composite resin background was saved as the control group. ΔE values were calculated from the ΔL, Δa and Δb values between control and test groups and data were analyzed with one-way variance analysis (ANOVA) and mean values were compared by the Tukey HSD test (α = 0.05). One-way ANOVA of ΔL, Δa, Δb and ΔE values of control and test groups revealed significant differences for backgrounds and seldom for cement color groups (p the 0.05). Only zirconium implant abutment groups and gold palladium abutment with universal shade cement group were found to be clinically acceptable (ΔE ≤ 3.0). Using titanium or gold-palladium abutments for implant supported all ceramics will be esthetically questionable and white opaque cement will be helpful to mask the dark color of titanium abutment.

Quantification of video-taped images in microcirculation research using inexpensive imaging software (Adobe Photoshop).

PubMed

Brunner, J; Krummenauer, F; Lehr, H A

2000-04-01

Study end-points in microcirculation research are usually video-taped images rather than numeric computer print-outs. Analysis of these video-taped images for the quantification of microcirculatory parameters usually requires computer-based image analysis systems. Most software programs for image analysis are custom-made, expensive, and limited in their applicability to selected parameters and study end-points. We demonstrate herein that an inexpensive, commercially available computer software (Adobe Photoshop), run on a Macintosh G3 computer with inbuilt graphic capture board provides versatile, easy to use tools for the quantification of digitized video images. Using images obtained by intravital fluorescence microscopy from the pre- and postischemic muscle microcirculation in the skinfold chamber model in hamsters, Photoshop allows simple and rapid quantification (i) of microvessel diameters, (ii) of the functional capillary density and (iii) of postischemic leakage of FITC-labeled high molecular weight dextran from postcapillary venules. We present evidence of the technical accuracy of the software tools and of a high degree of interobserver reliability. Inexpensive commercially available imaging programs (i.e., Adobe Photoshop) provide versatile tools for image analysis with a wide range of potential applications in microcirculation research.

The effect of parental factors in children with large cup-to-disc ratios.

PubMed

Park, Hae-Young Lopilly; Ha, Min Ji; Shin, Sun Young

2017-01-01

To investigate large cup-to-disc ratios (CDR) in children and to determine the relationship between parental CDR and clinical characteristics associated with glaucoma. Two hundred thirty six children aged 6 to 12 years with CDR ≥ 0.6 were enrolled in this study. Subjects were classified into two groups based on parental CDR: disc suspect children with disc suspect (CDR ≥0.6) parents and disc suspect children without disc suspect parents. Ocular variables were compared between the two groups. Of the 236 disc suspect children, 100 (42.4%) had at least one disc suspect parent. Intraocular pressure (IOP) was higher in disc suspect children with disc suspect parents (16.52±2.66 mmHg) than in disc suspect children without disc suspect parents (14.38±2.30 mmHg, p = 0.023). In the group with disc suspect parents, vertical CDR significantly correlated with IOP (R = -0.325, p = 0.001), average retinal nerve fiber layer (RNFL) thickness (R = -0.319, p = 0.001), rim area (R = -0.740, p = 0.001), and cup volume (R = 0.499, p = 0.001). However, spherical equivalent (R = 0.333, p = 0.001), AL (R = -0.223, p = 0.009), and disc area (R = 0.325, p = 0.001) significantly correlated with vertical CDR in disc suspect children without disc suspect parents, in contrast to those with disc suspect parents. Larger vertical CDR was associated with the presence of disc suspect parents (p = 0.001), larger disc area (p = 0.001), thinner rim area (p = 0.001), larger average CDR (p = 0.001), and larger cup volume (p = 0.021). Family history of large CDR was a significant factor associated with large vertical CDR in children. In children with disc suspect parents, there were significant correlations between IOP and average RNFL thickness and vertical CDR.

Qualification process of CR system and quantification of digital image quality

NASA Astrophysics Data System (ADS)

Garnier, P.; Hun, L.; Klein, J.; Lemerle, C.

2013-01-01

CEA Valduc uses several X-Ray generators to carry out many inspections: void search, welding expertise, gap measurements, etc. Most of these inspections are carried out on silver based plates. For several years, the CEA/Valduc has decided to qualify new devices such as digital plates or CCD/flat panel plates. On one hand, the choice of this technological orientation is to forecast the assumed and eventual disappearance of silver based plates; on the other hand, it is also to keep our skills mastering up-to-date. The main improvement brought by numerical plates is the continuous progress of the measurement accuracy, especially with image data processing. It is now common to measure defects thickness or depth position within a part. In such applications, data image processing is used to obtain complementary information compared to scanned silver based plates. This scanning procedure is harmful for measurements which imply a data corruption of the resolution, the adding of numerical noise and is time expensive. Digital plates enable to suppress the scanning procedure and to increase resolution. It is nonetheless difficult to define, for digital images, single criteria for the image quality. A procedure has to be defined in order to estimate quality of the digital data itself; the impact of the scanning device and the configuration parameters are also to be taken into account. This presentation deals with the qualification process developed by CEA/Valduc for digital plates (DUR-NDT) based on the study of quantitative criteria chosen to define a direct numerical image quality that could be compared with scanned silver based pictures and the classical optical density. The versatility of the X-Ray parameters is also discussed (X-ray tension, intensity, time exposure). The aim is to be able to transfer the year long experience of CEA/Valduc with silver-based plates inspection to these new digital plates supports. This is an industrial stake.

Numerical computation of gravitational field of general extended body and its application to rotation curve study of galaxies

NASA Astrophysics Data System (ADS)

Fukushima, Toshio

2017-06-01

Reviewed are recently developed methods of the numerical integration of the gravitational field of general two- or three-dimensional bodies with arbitrary shape and mass density distribution: (i) an axisymmetric infinitely-thin disc (Fukushima 2016a, MNRAS, 456, 3702), (ii) a general infinitely-thin plate (Fukushima 2016b, MNRAS, 459, 3825), (iii) a plane-symmetric and axisymmetric ring-like object (Fukushima 2016c, AJ, 152, 35), (iv) an axisymmetric thick disc (Fukushima 2016d, MNRAS, 462, 2138), and (v) a general three-dimensional body (Fukushima 2016e, MNRAS, 463, 1500). The key techniques employed are (a) the split quadrature method using the double exponential rule (Takahashi and Mori, 1973, Numer. Math., 21, 206), (b) the precise and fast computation of complete elliptic integrals (Fukushima 2015, J. Comp. Appl. Math., 282, 71), (c) Ridder's algorithm of numerical differentiaion (Ridder 1982, Adv. Eng. Softw., 4, 75), (d) the recursive computation of the zonal toroidal harmonics, and (e) the integration variable transformation to the local spherical polar coordinates. These devices succesfully regularize the Newton kernel in the integrands so as to provide accurate integral values. For example, the general 3D potential is regularly integrated as Φ (\\vec{x}) = - G \\int_0^∞ ( \\int_{-1}^1 ( \\int_0^{2π} ρ (\\vec{x}+\\vec{q}) dψ ) dγ ) q dq, where \\vec{q} = q (√{1-γ^2} cos ψ, √{1-γ^2} sin ψ, γ), is the relative position vector referred to \\vec{x}, the position vector at which the potential is evaluated. As a result, the new methods can compute the potential and acceleration vector very accurately. In fact, the axisymmetric integration reproduces the Miyamoto-Nagai potential with 14 correct digits. The developed methods are applied to the gravitational field study of galaxies and protoplanetary discs. Among them, the investigation on the rotation curve of M33 supports a disc-like structure of the dark matter with a double-power-law surface mass density distribution. Fortran 90 subroutines to execute these methods and their test programs and sample outputs are available from the author's WEB site: https://www.researchgate.net/profile/Toshio_Fukushima/

Effects of disc warping on the inclination evolution of star-disc-binary systems

NASA Astrophysics Data System (ADS)

Zanazzi, J. J.; Lai, Dong

2018-07-01

Several recent studies have suggested that circumstellar discs in young stellar binaries may be driven into misalignement with their host stars due to the secular gravitational interactions between the star, disc, and the binary companion. The disc in such systems is twisted/warped due to the gravitational torques from the oblate central star and the external companion. We calculate the disc warp profile, taking into account the bending wave propagation and viscosity in the disc. We show that for typical protostellar disc parameters, the disc warp is small, thereby justifying the `flat-disc' approximation adopted in previous theoretical studies. However, the viscous dissipation associated with the small disc warp/twist tends to drive the disc towards alignment with the binary or the central star. We calculate the relevant time-scales for the alignment. We find that the alignment is effective for sufficiently cold discs with strong external torques, especially for systems with rapidly rotating stars, but is ineffective for the majority of the star-disc-binary systems. Viscous warp-driven alignment may be necessary to account for the observed spin-orbit alignment in multiplanet systems if these systems are accompanied by an inclined binary companion.

Simulating Dynamic Equilibria: A Class Experiment

NASA Astrophysics Data System (ADS)

Harrison, John A.; Buckley, Paul D.

2000-08-01

A first-order reversible reaction is simulated on an overhead projector using small coins or discs. A simulation is carried out in which initially there are 24 discs representing reactant A and none representing reactant B. At the end of each minute half of the reactant A discs get converted to reactant B, and one quarter of the reactant B discs get converted to reactant A discs. Equilibrium is established with 8 A discs and 16 B discs, and no further net change is observed as the simulation continues. Another simulation beginning with 48 A discs and 0 B discs leads at equilibrium to 16 A discs and 32 B discs. These results illustrate how dynamic equilibria are established and allow the introduction of the concept of an equilibrium constant. Le Châtelier's principle is illustrated by further simulations.

Gas turbine sealing apparatus

DOEpatents

Wiebe, David J; Wessell, Brian J; Ebert, Todd; Beeck, Alexander; Liang, George; Marussich, Walter H

2013-02-19

A gas turbine includes forward and aft rows of rotatable blades, a row of stationary vanes between the forward and aft rows of rotatable blades, an annular intermediate disc, and a seal housing apparatus. The forward and aft rows of rotatable blades are coupled to respective first and second portions of a disc/rotor assembly. The annular intermediate disc is coupled to the disc/rotor assembly so as to be rotatable with the disc/rotor assembly during operation of the gas turbine. The annular intermediate disc includes a forward side coupled to the first portion of the disc/rotor assembly and an aft side coupled to the second portion of the disc/rotor assembly. The seal housing apparatus is coupled to the annular intermediate disc so as to be rotatable with the annular intermediate disc and the disc/rotor assembly during operation of the gas turbine.

Manipulator having thermally conductive rotary joint for transferring heat from a test specimen

DOEpatents

Haney, S.J.; Stulen, R.H.; Toly, N.F.

1983-05-03

A manipulator for rotatably moving a test specimen in an ultra-high vacuum chamber includes a translational unit movable in three mutually perpendicular directions. A manipulator frame is rigidly secured to the translational unit for rotatably supporting a rotary shaft. A first copper disc is rigidly secured to an end of the rotary shaft for rotary movement within the vacuum chamber. A second copper disc is supported upon the first disc. The second disc receives a cryogenic cold head and does not rotate with the first disc. The second disc receives a cryogenic cold head and does not rotate with the first disc. A sapphire plate is interposed between the first and second discs to prevent galling of the copper material while maintaining high thermal conductivity between the first and second discs. A spring is disposed on the shaft to urge the second disc toward the first disc and compressingly engage the interposed sapphire plate. A specimen mount is secured to the first disc for rotation within the vacuum chamber. The specimen maintains high thermal conductivity with the second disc receiving the cryogenic transfer line.

On the diversity and statistical properties of protostellar discs

NASA Astrophysics Data System (ADS)

Bate, Matthew R.

2018-04-01

We present results from the first population synthesis study of protostellar discs. We analyse the evolution and properties of a large sample of protostellar discs formed in a radiation hydrodynamical simulation of star cluster formation. Due to the chaotic nature of the star formation process, we find an enormous diversity of young protostellar discs, including misaligned discs, and discs whose orientations vary with time. Star-disc interactions truncate discs and produce multiple systems. Discs may be destroyed in dynamical encounters and/or through ram-pressure stripping, but reform by later gas accretion. We quantify the distributions of disc mass and radii for protostellar ages up to ≈105 yr. For low-mass protostars, disc masses tend to increase with both age and protostellar mass. Disc radii range from of order 10 to a few hundred au, grow in size on time-scales ≲ 104 yr, and are smaller around lower mass protostars. The radial surface density profiles of isolated protostellar discs are flatter than the minimum mass solar nebula model, typically scaling as Σ ∝ r-1. Disc to protostar mass ratios rarely exceed two, with a typical range of Md/M* = 0.1-1 to ages ≲ 104 yr and decreasing thereafter. We quantify the relative orientation angles of circumstellar discs and the orbit of bound pairs of protostars, finding a preference for alignment that strengths with decreasing separation. We also investigate how the orientations of the outer parts of discs differ from the protostellar and inner disc spins for isolated protostars and pairs.

Linear analysis of the evolution of nearly polar low-mass circumbinary discs

NASA Astrophysics Data System (ADS)

Lubow, Stephen H.; Martin, Rebecca G.

2018-01-01

In a recent paper Martin & Lubow showed through simulations that an initially tilted disc around an eccentric binary can evolve to polar alignment in which the disc lies perpendicular to the binary orbital plane. We apply linear theory to show both analytically and numerically that a nearly polar aligned low-mass circumbinary disc evolves to polar alignment and determine the alignment time-scale. Significant disc evolution towards the polar state around moderately eccentric binaries can occur for typical protostellar disc parameters in less than a typical disc lifetime for binaries with orbital periods of order 100 yr or less. Resonant torques are much less effective at truncating the inner parts of circumbinary polar discs than the inner parts of coplanar discs. For polar discs, they vanish for a binary eccentricity of unity. The results agree with the simulations in showing that discs can evolve to a polar state. Circumbinary planets may then form in such discs and reside on polar orbits.

Audio Restoration

NASA Astrophysics Data System (ADS)

Esquef, Paulo A. A.

The first reproducible recording of human voice was made in 1877 on a tinfoil cylinder phonograph devised by Thomas A. Edison. Since then, much effort has been expended to find better ways to record and reproduce sounds. By the mid-1920s, the first electrical recordings appeared and gradually took over purely acoustic recordings. The development of electronic computers, in conjunction with the ability to record data onto magnetic or optical media, culminated in the standardization of compact disc format in 1980. Nowadays, digital technology is applied to several audio applications, not only to improve the quality of modern and old recording/reproduction techniques, but also to trade off sound quality for less storage space and less taxing transmission capacity requirements.

A new in vivo animal model to create intervertebral disc degeneration characterized by MRI, radiography, CT/discogram, biochemistry, and histology.

PubMed

Zhou, HaoWei; Hou, ShuXun; Shang, WeiLin; Wu, WenWen; Cheng, Yao; Mei, Fang; Peng, BaoGan

2007-04-15

A new in vivo sheep model was developed that produced disc degeneration through the injection of 5-bromodeoxyuridine (BrdU) into the intervertebral disc. This process was studied using magnetic resonance imaging (MRI), radiography, CT/discogram, histology, and biochemistry. To develop a sheep model of intervertebral disc degeneration that more faithfully mimics the pathologic hallmarks of human intervertebral disc degeneration. Recent studies have shown age-related alterations in proteoglycan structure and organization in human intervertebral discs. An animal model that involves the use of age-related changes in disc cells can be beneficial over other more invasive degenerative models that involves directly damaging the matrix of disc tissue. Twelve sheep were injected with BrdU or vehicle (phosphate-buffered saline) into the central region of separate lumbar discs. Intact discs were used as controls. At the 2-, 6-, 10-, and 14-week time points, discs underwent MRI, radiography, histology, and biochemical analyses. A CT/discogram study was performed at the 14-week time point. MRI demonstrated a progressive loss of T2-weighted signal intensity at BrdU-injected discs over the 14-week study period. Radiograph findings included osteophyte and disc space narrowing formed by 10 weeks post-BrdU treatment. CT discography demonstrated internal disc disruption in several BrdU-treated discs at the 14-week time point. Histology showed a progressive loss of the normal architecture and cell density of discs from the 2-week time point to the 14-week time point. A progressive loss of cell proliferation capacity, water content, and proteoglycans was also documented. BrdU injection into the central region of sheep discs resulted in degeneration of intervertebral discs. This progressive, degenerative process was confirmed using MRI, histology, and by observing changes in biochemistry. Degeneration occurred in a manner that was similar to that observed in human disc degeneration.

Electronic still camera

NASA Astrophysics Data System (ADS)

Holland, S. Douglas

1992-09-01

A handheld, programmable, digital camera is disclosed that supports a variety of sensors and has program control over the system components to provide versatility. The camera uses a high performance design which produces near film quality images from an electronic system. The optical system of the camera incorporates a conventional camera body that was slightly modified, thus permitting the use of conventional camera accessories, such as telephoto lenses, wide-angle lenses, auto-focusing circuitry, auto-exposure circuitry, flash units, and the like. An image sensor, such as a charge coupled device ('CCD') collects the photons that pass through the camera aperture when the shutter is opened, and produces an analog electrical signal indicative of the image. The analog image signal is read out of the CCD and is processed by preamplifier circuitry, a correlated double sampler, and a sample and hold circuit before it is converted to a digital signal. The analog-to-digital converter has an accuracy of eight bits to insure accuracy during the conversion. Two types of data ports are included for two different data transfer needs. One data port comprises a general purpose industrial standard port and the other a high speed/high performance application specific port. The system uses removable hard disks as its permanent storage media. The hard disk receives the digital image signal from the memory buffer and correlates the image signal with other sensed parameters, such as longitudinal or other information. When the storage capacity of the hard disk has been filled, the disk can be replaced with a new disk.

Electronic Still Camera

NASA Technical Reports Server (NTRS)

Holland, S. Douglas (Inventor)

1992-01-01

A handheld, programmable, digital camera is disclosed that supports a variety of sensors and has program control over the system components to provide versatility. The camera uses a high performance design which produces near film quality images from an electronic system. The optical system of the camera incorporates a conventional camera body that was slightly modified, thus permitting the use of conventional camera accessories, such as telephoto lenses, wide-angle lenses, auto-focusing circuitry, auto-exposure circuitry, flash units, and the like. An image sensor, such as a charge coupled device ('CCD') collects the photons that pass through the camera aperture when the shutter is opened, and produces an analog electrical signal indicative of the image. The analog image signal is read out of the CCD and is processed by preamplifier circuitry, a correlated double sampler, and a sample and hold circuit before it is converted to a digital signal. The analog-to-digital converter has an accuracy of eight bits to insure accuracy during the conversion. Two types of data ports are included for two different data transfer needs. One data port comprises a general purpose industrial standard port and the other a high speed/high performance application specific port. The system uses removable hard disks as its permanent storage media. The hard disk receives the digital image signal from the memory buffer and correlates the image signal with other sensed parameters, such as longitudinal or other information. When the storage capacity of the hard disk has been filled, the disk can be replaced with a new disk.

Flat panel detectors--closing the (digital) gap in chest and skeletal radiology.

PubMed

Reiff, K J

1999-08-01

In the radiological department today the majority of all X-ray procedures on chest and skeletal radiography is performed with classical film-screen-systems. Using digital luminescence radiography (DLR or CR, which stands for Computed Radiography) as a technique has shown a way to replace this 100-year-old procedure of doing general radiography work by acquiring the X-rays digitally via phosphor screens, but this approach has faced criticism from lots of radiologists world wide and therefore has not been widely accepted except in the intensive care environment. A new technology is now rising based on the use of so called flat panel X-ray (FD) detectors. Semi-conducting material detects the X-rays in digital form directly and creates an instantaneous image for display, distribution and diagnosis. This ability combined with a large field of view and compared to existing methods--excellent detective quantum efficiency represents a revolutionary step for chest and skeletal radiography and will put basic X-ray-work back into the focus of radiological solutions. This paper will explain the basic technology of flat panel detectors, possible system solutions based on this new technology, aspects of the user interface influencing the system utilization and versatility as well as the possibility to redefine the patient examination process for chest and skeletal radiography. Furthermore the author discusses limitations for the first released systems, upgrades for the installed base and possible scenarios for the future, e.g. fluoroscopy or angiography application.

Low-cost, digital lock-in module with external reference for coating glass transmission/reflection spectrophotometer

NASA Astrophysics Data System (ADS)

Alonso, R.; Villuendas, F.; Borja, J.; Barragán, L. A.; Salinas, I.

2003-05-01

A versatile, low-cost, digital signal processor (DSP) based lock-in module with external reference is described. This module is used to implement an industrial spectrophotometer for measuring spectral transmission and reflection of automotive and architectonic coating glasses over the ultraviolet, visible and near-infrared wavelength range. The light beams are modulated with an optical chopper. A digital phase-locked loop (DPLL) is used to lock the lock-in to the chop frequency. The lock-in rejects the ambient radiation and permits the spectrophotometer to work in the presence of ambient light. The algorithm that implements the dual lock-in and the DPLL in the DSP56002 evaluation module from Motorola is described. The use of a DSP allows implementation of the lock-in and DPLL by software, which gives flexibility and programmability to the system. Lock-in module cost, under 300 euro, is an important parameter taking into account that two modules are used in the system. Besides, the algorithms implemented in this DSP can be directly implemented in the latest DSP generations. The DPLL performance and the spectrophotometer are characterized. Capture and lock DPLL ranges have been measured and checked to be greater than the chop frequency drifts. The lock-in measured frequency response shows that the lock-in performs as theoretically predicted.

Digitally programmable microfluidic automaton for multiscale combinatorial mixing and sample processing†

PubMed Central

Jensen, Erik C.; Stockton, Amanda M.; Chiesl, Thomas N.; Kim, Jungkyu; Bera, Abhisek; Mathies, Richard A.

2013-01-01

A digitally programmable microfluidic Automaton consisting of a 2-dimensional array of pneumatically actuated microvalves is programmed to perform new multiscale mixing and sample processing operations. Large (µL-scale) volume processing operations are enabled by precise metering of multiple reagents within individual nL-scale valves followed by serial repetitive transfer to programmed locations in the array. A novel process exploiting new combining valve concepts is developed for continuous rapid and complete mixing of reagents in less than 800 ms. Mixing, transfer, storage, and rinsing operations are implemented combinatorially to achieve complex assay automation protocols. The practical utility of this technology is demonstrated by performing automated serial dilution for quantitative analysis as well as the first demonstration of on-chip fluorescent derivatization of biomarker targets (carboxylic acids) for microchip capillary electrophoresis on the Mars Organic Analyzer. A language is developed to describe how unit operations are combined to form a microfluidic program. Finally, this technology is used to develop a novel microfluidic 6-sample processor for combinatorial mixing of large sets (>26 unique combinations) of reagents. The digitally programmable microfluidic Automaton is a versatile programmable sample processor for a wide range of process volumes, for multiple samples, and for different types of analyses. PMID:23172232

Compact discs as versatile cost-effective substrates for releasable nanopatterned aluminium films

NASA Astrophysics Data System (ADS)

Barrios, Carlos Angulo; Canalejas-Tejero, Víctor

2015-02-01

We demonstrate that standard polycarbonate compact disk surfaces can provide unique adhesion to Al films that is both strong enough to permit Al film nanopatterning and weak enough to allow easy nanopatterned Al film detachment using Scotch tape. Transferred Al nanohole arrays on Scotch tape exhibit excellent optical and plasmonic performance.We demonstrate that standard polycarbonate compact disk surfaces can provide unique adhesion to Al films that is both strong enough to permit Al film nanopatterning and weak enough to allow easy nanopatterned Al film detachment using Scotch tape. Transferred Al nanohole arrays on Scotch tape exhibit excellent optical and plasmonic performance. Electronic supplementary information (ESI) available: 1. Optical simulations (Fig. SI.1); 2. Optical coupling via an Al NHA on the Scotch tape (Fig. SI.2); 3. Electrostatics-based opto-mechanical cantilever (Fig. SI.3). Video 1. Transfer of the Al film nanostructured with a nanohole array from a polycarbonate CD surface onto a Scotch tape; Video 2. Opto-mechanical electrostatics-based sensor: electrical attraction. Video 3. Opto-mechanical electrostatics-based sensor: electrical repulsion. See DOI: 10.1039/c4nr06271j

Investigation of Product Performance of Al-Metal Matrix Composites Brake Disc using Finite Element Analysis

NASA Astrophysics Data System (ADS)

Fatchurrohman, N.; Marini, C. D.; Suraya, S.; Iqbal, AKM Asif

2016-02-01

The increasing demand of fuel efficiency and light weight components in automobile sectors have led to the development of advanced material parts with improved performance. A specific class of MMCs which has gained a lot of attention due to its potential is aluminium metal matrix composites (Al-MMCs). Product performance investigation of Al- MMCs is presented in this article, where an Al-MMCs brake disc is analyzed using finite element analysis. The objective is to identify the potentiality of replacing the conventional iron brake disc with Al-MMCs brake disc. The simulation results suggested that the MMCs brake disc provided better thermal and mechanical performance as compared to the conventional cast iron brake disc. Although, the Al-MMCs brake disc dissipated higher maximum temperature compared to cast iron brake disc's maximum temperature. The Al-MMCs brake disc showed a well distributed temperature than the cast iron brake disc. The high temperature developed at the ring of the disc and heat was dissipated in circumferential direction. Moreover, better thermal dissipation and conduction at brake disc rotor surface played a major influence on the stress. As a comparison, the maximum stress and strain of Al-MMCs brake disc was lower than that induced on the cast iron brake disc.

Are Collapsed Cervical Discs Amenable to Total Disc Arthroplasty?: Analysis of Prospective Clinical Data With 2-Year Follow Up.

PubMed

Patwardhan, Avinash G; Carandang, Gerard; Voronov, Leonard I; Havey, Robert M; Paul, Gary A; Lauryssen, Carl; Coric, Domagoj; Dimmig, Thomas; Musante, David

2016-12-15

Analysis of prospectively collected radiographic data. To investigate the influence of preoperative index-level range of motion (ROM) and disc height on postoperative ROM after cervical total disc arthroplasty (TDA) using compressible disc prostheses. Clinical studies demonstrate benefits of motion preservation over fusion; however, questions remain unanswered as to which preoperative factors have the ability to identify patients who are most likely to have good postoperative motion, which is the primary rationale for TDA. We analyzed prospectively collected data from a single-arm, multicenter study with 2-year follow up of 30 patients with 48 implanted levels. All received compressible cervical disc prostheses of 6 mm-height (M6C, Spinal Kinetics, Sunnyvale, CA). The influence of index-level preoperative disc height and ROM (each with two levels: below-median and above-median) on postoperative ROM was analyzed using 2 x 2 ANOVA. We further analyzed the radiographic outcomes of a subset of discs with preoperative height less than 3 mm, the so-called "collapsed" discs. Shorter (3.0 ± 0.4 mm) discs were significantly less mobile preoperatively than taller (4.4 ± 0.5 mm) discs (6.7° vs. 10.5°, P = 0.01). The postoperative ROM did not differ between the shorter and taller discs (5.6° vs. 5.0°, P = 0.63). Tall discs that were less mobile preoperatively had significantly smaller postoperative ROM than short discs with above-median preoperative mobility (P < 0.05). The "collapsed discs" (n = 8) were less mobile preoperatively compared with all discs combined (5.1° vs. 8.6°, P < 0.01). These discs were distracted to more than two times the preoperative height, from 2.6 to 5.7 mm, and had significantly greater postoperative ROM than all discs combined (7.6° vs. 5.3°, P < 0.05). We observed a significant interaction between preoperative index-level disc height and ROM in influencing postoperative ROM. Although limited by small sample size, the results suggest discs with preoperative height less than 3 mm may be amenable to disc arthroplasty using compressible disc prostheses. 2.

CT morphometry of adult thoracic intervertebral discs.

PubMed

Fletcher, Justin G R; Stringer, Mark D; Briggs, Christopher A; Davies, Tilman M; Woodley, Stephanie J

2015-10-01

Despite being commonly affected by degenerative disorders, there are few data on normal thoracic intervertebral disc dimensions. A morphometric analysis of adult thoracic intervertebral discs was, therefore, undertaken. Archival computed tomography scans of 128 recently deceased individuals (70 males, 58 females, 20-79 years) with no known spinal pathology were analysed to determine thoracic disc morphometry and variations with disc level, sex and age. Reliability was assessed by intraclass correlation coefficients (ICCs). Anterior and posterior intervertebral disc heights and axial dimensions were significantly greater in men (anterior disc height 4.0±1.4 vs 3.6±1.3 mm; posterior disc height 3.6±0.90 vs 3.4±0.93 mm; p<0.01). Disc heights and axial dimensions at T4-5 were similar or smaller than at T2-3, but thereafter increased caudally (mean anterior disc height T4-5 and T10-11, 2.7±0.7 and 5.4±1.2 mm, respectively, in men; 2.6±0.8 and 5.1±1.3 mm, respectively, in women; p<0.05). Except at T2-3, anterior disc height decreased with advancing age and anteroposterior and transverse disc dimensions increased; posterior and middle disc heights and indices of disc shape showed no consistent statistically significant changes. Most parameters showed substantial to almost perfect agreement for intra- and inter-rater reliability. Thoracic disc morphometry varies significantly and consistently with disc level, sex and age. This study provides unique reference data on adult thoracic intervertebral disc morphometry, which may be useful when interpreting pathological changes and for future biomechanical and functional studies.

Asymmetric MHD outflows/jets from accreting T Tauri stars

NASA Astrophysics Data System (ADS)

Dyda, S.; Lovelace, R. V. E.; Ustyugova, G. V.; Lii, P. S.; Romanova, M. M.; Koldoba, A. V.

2015-06-01

Observations of jets from young stellar objects reveal the asymmetric outflows from some sources. A large set of 2.5D magnetohydrodynamic simulations was carried out for axisymmetric viscous/diffusive disc accretion to rotating magnetized stars for the purpose of assessing the conditions where the outflows are asymmetric relative to the equatorial plane. We consider initial magnetic fields that are symmetric about the equatorial plane and consist of a radially distributed field threading the disc (disc field) and a stellar dipole field. (1) For pure disc-fields the symmetry or asymmetry of the outflows is affected by the mid-plane plasma β of the disc. For discs with small plasma β, outflows are symmetric to within 10 per cent over time-scales of hundreds of inner disc orbits. For higher β discs, the coupling of the upper and lower coronal plasmas is broken, and quasi-periodic field motion leads to asymmetric episodic outflows. (2) Accreting stars with a stellar dipole field and no disc-field exhibit episodic, two component outflows - a magnetospheric wind and an inner disc wind. Both are characterized by similar velocity profiles but the magnetospheric wind has densities ≳ 10 times that of the disc wind. (3) Adding a disc field parallel to the stellar dipole field enhances the magnetospheric winds but suppresses the disc wind. (4) Adding a disc field which is antiparallel to the stellar dipole field in the disc suppresses the magnetospheric and disc winds. Our simulations reproduce some key features of observations of asymmetric outflows of T Tauri stars.

The Correlation between Insertion Depth of Prodisc-C Artificial Disc and Postoperative Kyphotic Deformity: Clinical Importance of Insertion Depth of Artificial Disc.

PubMed

Lee, Do-Youl; Kim, Se-Hoon; Suh, Jung-Keun; Cho, Tai-Hyoung; Chung, Yong-Gu

2012-09-01

This study was designed to investigate the correlation between insertion depth of artificial disc and postoperative kyphotic deformity after Prodisc-C total disc replacement surgery, and the range of artificial disc insertion depth which is effective in preventing postoperative whole cervical or segmental kyphotic deformity. A retrospective radiological analysis was performed in 50 patients who had undergone single level total disc replacement surgery. Records were reviewed to obtain demographic data. Preoperative and postoperative radiographs were assessed to determine C2-7 Cobb's angle and segmental angle and to investigate postoperative kyphotic deformity. A formula was introduced to calculate insertion depth of Prodisc-C artificial disc. Statistical analysis was performed to search the correlation between insertion depth of Prodisc-C artificial disc and postoperative kyphotic deformity, and to estimate insertion depth of Prodisc-C artificial disc to prevent postoperative kyphotic deformity. In this study no significant statistical correlation was observed between insertion depth of Prodisc-C artificial disc and postoperative kyphotic deformity regarding C2-7 Cobb's angle. Statistical correlation between insertion depth of Prodisc-C artificial disc and postoperative kyphotic deformity was observed regarding segmental angle (p<0.05). It failed to estimate proper insertion depth of Prodisc-C artificial disc effective in preventing postoperative kyphotic deformity. Postoperative segmental kyphotic deformity is associated with insertion depth of Prodisc-C artificial disc. Anterior located artificial disc leads to lordotic segmental angle and posterior located artificial disc leads to kyphotic segmental angle postoperatively. But C2-7 Cobb's angle is not affected by artificial disc location after the surgery.

Ranges of Cervical Intervertebral Disc Deformation During an In Vivo Dynamic Flexion–Extension of the Neck

PubMed Central

Yu, Yan; Mao, Haiqing; Li, Jing-Sheng; Tsai, Tsung-Yuan; Cheng, Liming; Wood, Kirkham B.; Li, Guoan; Cha, Thomas D.

2017-01-01

While abnormal loading is widely believed to cause cervical spine disc diseases, in vivo cervical disc deformation during dynamic neck motion has not been well delineated. This study investigated the range of cervical disc deformation during an in vivo functional flexion–extension of the neck. Ten asymptomatic human subjects were tested using a combined dual fluoroscopic imaging system (DFIS) and magnetic resonance imaging (MRI)-based three-dimensional (3D) modeling technique. Overall disc deformation was determined using the changes of the space geometry between upper and lower endplates of each intervertebral segment (C3/4, C4/5, C5/6, and C6/7). Five points (anterior, center, posterior, left, and right) of each disc were analyzed to examine the disc deformation distributions. The data indicated that between the functional maximum flexion and extension of the neck, the anterior points of the discs experienced large changes of distraction/compression deformation and shear deformation. The higher level discs experienced higher ranges of disc deformation. No significant difference was found in deformation ranges at posterior points of all the discs. The data indicated that the range of disc deformation is disc level dependent and the anterior region experienced larger changes of deformation than the center and posterior regions, except for the C6/7 disc. The data obtained from this study could serve as baseline knowledge for the understanding of the cervical spine disc biomechanics and for investigation of the biomechanical etiology of disc diseases. These data could also provide insights for development of motion preservation surgeries for cervical spine. PMID:28334358

Ranges of Cervical Intervertebral Disc Deformation During an In Vivo Dynamic Flexion-Extension of the Neck.

PubMed

Yu, Yan; Mao, Haiqing; Li, Jing-Sheng; Tsai, Tsung-Yuan; Cheng, Liming; Wood, Kirkham B; Li, Guoan; Cha, Thomas D

2017-06-01

While abnormal loading is widely believed to cause cervical spine disc diseases, in vivo cervical disc deformation during dynamic neck motion has not been well delineated. This study investigated the range of cervical disc deformation during an in vivo functional flexion-extension of the neck. Ten asymptomatic human subjects were tested using a combined dual fluoroscopic imaging system (DFIS) and magnetic resonance imaging (MRI)-based three-dimensional (3D) modeling technique. Overall disc deformation was determined using the changes of the space geometry between upper and lower endplates of each intervertebral segment (C3/4, C4/5, C5/6, and C6/7). Five points (anterior, center, posterior, left, and right) of each disc were analyzed to examine the disc deformation distributions. The data indicated that between the functional maximum flexion and extension of the neck, the anterior points of the discs experienced large changes of distraction/compression deformation and shear deformation. The higher level discs experienced higher ranges of disc deformation. No significant difference was found in deformation ranges at posterior points of all the discs. The data indicated that the range of disc deformation is disc level dependent and the anterior region experienced larger changes of deformation than the center and posterior regions, except for the C6/7 disc. The data obtained from this study could serve as baseline knowledge for the understanding of the cervical spine disc biomechanics and for investigation of the biomechanical etiology of disc diseases. These data could also provide insights for development of motion preservation surgeries for cervical spine.

The presence of pleiotrophin in the human intervertebral disc is associated with increased vascularization: an immunohistologic study.

PubMed

Johnson, William E B; Patterson, Angela M; Eisenstein, Stephen M; Roberts, Sally

2007-05-20

An immunohistological study of surgical specimens of human intervertebral disc. To examine the presence of pleiotrophin in diseased or damaged intervertebral disc tissue and the association between its presence and the extent of tissue vascularization and innervation. Increased levels of pleiotrophin, a growth and differentiation factor that is active in various pathophysiologic processes, including angiogenesis, has been associated with osteoarthritic changes of human articular cartilage. The association between pleiotrophin expression and pathologic conditions of the human intervertebral disc is unknown. Specimens of human lumbar intervertebral discs, obtained following surgical discectomy, were divided into 3 groups: non-degenerated discs (n = 7), degenerated discs (n = 6), and prolapsed discs (n = 11). Serial tissue sections of each specimen were immunostained to determine the presence of pleiotrophin, blood vessels (CD34-positive endothelial cells), and nerves (neurofilament 200 kDa [NF200]-positive nerve fibers). Pleiotrophin immunoreactivity was seen in disc cells, endothelial cells, and in the extracellular matrix in most specimens of intervertebral disc but was most prevalent in vascularized tissue in prolapsed discs. There was a significant correlation between the presence of pleiotrophin-positive disc cells and that of CD34-positive blood vessels. NF200-positive nerves were seen in vascularized areas of more degenerated discs, but nerves did not appear to codistribute with blood vessels or pleiotrophin positivity in prolapsed discs. Pleiotrophin is present in pathologic human intervertebral discs, and its prevalence and distribution suggest that it may play a role in neovascularization of diseased or damaged disc tissue.

MRI evaluation of spontaneous intervertebral disc degeneration in the alpaca cervical spine.

PubMed

Stolworthy, Dean K; Bowden, Anton E; Roeder, Beverly L; Robinson, Todd F; Holland, Jacob G; Christensen, S Loyd; Beatty, Amanda M; Bridgewater, Laura C; Eggett, Dennis L; Wendel, John D; Stieger-Vanegas, Susanne M; Taylor, Meredith D

2015-12-01

Animal models have historically provided an appropriate benchmark for understanding human pathology, treatment, and healing, but few animals are known to naturally develop intervertebral disc degeneration. The study of degenerative disc disease and its treatment would greatly benefit from a more comprehensive, and comparable animal model. Alpacas have recently been presented as a potential large animal model of intervertebral disc degeneration due to similarities in spinal posture, disc size, biomechanical flexibility, and natural disc pathology. This research further investigated alpacas by determining the prevalence of intervertebral disc degeneration among an aging alpaca population. Twenty healthy female alpacas comprised two age subgroups (5 young: 2-6 years; and 15 older: 10+ years) and were rated according to the Pfirrmann-grade for degeneration of the cervical intervertebral discs. Incidence rates of degeneration showed strong correlations with age and spinal level: younger alpacas were nearly immune to developing disc degeneration, and in older animals, disc degeneration had an increased incidence rate and severity at lower cervical levels. Advanced disc degeneration was present in at least one of the cervical intervertebral discs of 47% of the older alpacas, and it was most common at the two lowest cervical intervertebral discs. The prevalence of intervertebral disc degeneration encourages further investigation and application of the lower cervical spine of alpacas and similar camelids as a large animal model of intervertebral disc degeneration. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Archival-grade optical disc design and international standards

NASA Astrophysics Data System (ADS)

Fujii, Toru; Kojyo, Shinichi; Endo, Akihisa; Kodaira, Takuo; Mori, Fumi; Shimizu, Atsuo

2015-09-01

Optical discs currently on the market exhibit large variations in life span among discs, making them unsuitable for certain business applications. To assess and potentially mitigate this problem, we performed accelerated degradation testing under standard ISO conditions, determined the probable disc failure mechanisms, and identified the essential criteria necessary for a stable disc composition. With these criteria as necessary conditions, we analyzed the physical and chemical changes that occur in the disc components, on the basis of which we determined technological measures to reduce these degradation processes. By applying these measures to disc fabrication, we were able to develop highly stable optical discs.

Thermal analysis of disc brakes using finite element method

NASA Astrophysics Data System (ADS)

Jaenudin, Jamari, J.; Tauviqirrahman, M.

2017-01-01

Disc brakes are components of a vehicle that serve to slow or stop the rotation of the wheel. This paper discusses the phenomenon of heat distribution on the brake disc during braking. Heat distribution on the brake disc is caused by kinetic energy changing into mechanical energy. Energy changes occur during the braking process due to friction between the surface of the disc and a disc pad. The temperature resulting from this friction rises high. This thermal analysis on brake discs is aimed to evaluate the performance of an electric car in the braking process. The aim of this study is to analyze the thermal behavior of the brake discs using the Finite Element Method (FEM) through examining the heat distribution on the brake disc using 3-D modeling. Results obtained from the FEM reflect the effects of high heat due to the friction between the disc pad with the disc rotor. Results of the simulation study are used to identify the effect of the heat distribution that occurred during the braking process.

Manipulator having thermally conductive rotary joint for transferring heat from a test specimen

DOEpatents

Haney, Steven J.; Stulen, Richard H.; Toly, Norman F.

1985-01-01

A manipulator for rotatably moving a test specimen in an ultra-high vacuum chamber includes a translational unit movable in three mutually perpendicular directions. A manipulator frame is rigidly secured to the translational unit for rotatably supporting a rotary shaft. A first copper disc is rigidly secured to an end of the rotary shaft for rotary movement within the vacuum chamber. A second copper disc is supported upon the first disc. The second disc receives a cryogenic cold head and does not rotate with the first disc. A sapphire plate is interposed between the first and second discs to prevent galling of the copper material while maintaining high thermal conductivity between the first and second discs. A spring is disposed on the shaft to urge the second disc toward the first disc and compressingly engage the interposed sapphire plate. A specimen mount is secured to the first disc for rotation within the vacuum chamber. The specimen maintains high thermal conductivity with the second disc receiving the cryogenic transfer line.

Circumplanetary discs around young giant planets: a comparison between core-accretion and disc instability

NASA Astrophysics Data System (ADS)

Szulágyi, J.; Mayer, L.; Quinn, T.

2017-01-01

Circumplanetary discs can be found around forming giant planets, regardless of whether core accretion or gravitational instability built the planet. We carried out state-of-the-art hydrodynamical simulations of the circumplanetary discs for both formation scenarios, using as similar initial conditions as possible to unveil possible intrinsic differences in the circumplanetary disc mass and temperature between the two formation mechanisms. We found that the circumplanetary discs' mass linearly scales with the circumstellar disc mass. Therefore, in an equally massive protoplanetary disc, the circumplanetary discs formed in the disc instability model can be only a factor of 8 more massive than their core-accretion counterparts. On the other hand, the bulk circumplanetary disc temperature differs by more than an order of magnitude between the two cases. The subdiscs around planets formed by gravitational instability have a characteristic temperature below 100 K, while the core-accretion circumplanetary discs are hot, with temperatures even greater than 1000 K when embedded in massive, optically thick protoplanetary discs. We explain how this difference can be understood as the natural result of the different formation mechanisms. We argue that the different temperatures should persist up to the point when a full-fledged gas giant forms via disc instability; hence, our result provides a convenient criterion for observations to distinguish between the two main formation scenarios by measuring the bulk temperature in the planet vicinity.

Detection of hypertensive retinopathy using vessel measurements and textural features.

PubMed

Agurto, Carla; Joshi, Vinayak; Nemeth, Sheila; Soliz, Peter; Barriga, Simon

2014-01-01

Features that indicate hypertensive retinopathy have been well described in the medical literature. This paper presents a new system to automatically classify subjects with hypertensive retinopathy (HR) using digital color fundus images. Our method consists of the following steps: 1) normalization and enhancement of the image; 2) determination of regions of interest based on automatic location of the optic disc; 3) segmentation of the retinal vasculature and measurement of vessel width and tortuosity; 4) extraction of color features; 5) classification of vessel segments as arteries or veins; 6) calculation of artery-vein ratios using the six widest (major) vessels for each category; 7) calculation of mean red intensity and saturation values for all arteries; 8) calculation of amplitude-modulation frequency-modulation (AM-FM) features for entire image; and 9) classification of features into HR and non-HR using linear regression. This approach was tested on 74 digital color fundus photographs taken with TOPCON and CANON retinal cameras using leave-one out cross validation. An area under the ROC curve (AUC) of 0.84 was achieved with sensitivity and specificity of 90% and 67%, respectively.

Preliminary results of a computerized Placido disk surgical corneal topographer

NASA Astrophysics Data System (ADS)

Carvalho, Luis A.; Tonissi, S. A.; Castro, Jarbas C.

1999-06-01

We have developed a novel instrument for computerized corneal topography during surgery. The instrument measures a region of approximately 7 mm in diameter, providing the surgeon with precise values of power and astigmatism. The system is based on a Placido Disc projecting system, which is attached to the objective lens of the surgical microscope. The Placido Disc pattern is reflected by a 50% beam splitter attached to the body of the microscope. At the beam splitter we installed our home-made adaptor and a CCD monochromatic high resolution camera. A high quality frame grabber is installed on a PC and images are digitized at a 480x640 resolution. Algorithms based on image processing techniques were implemented for edge detection of pattern. Calibrating curves based on 4 spherical surfaces were generated and approximately 3600 points were calculated for each exam. Preliminary measurements on 10 healthy corneas were compared with the measurements made on an EyeSys Corneal Topographer. Mean deviation was 0.05 for radius of curvature, 0.24 D for power and 5 degrees for cylinder. This system, with some improvements, may be successfully used to diminish high post surgical astigmatisms in surgeries such as cataract and corneal transplant. This system could also be used to gather preoperative data in corneal topography assisted LASIK.

Numerical computation of gravitational field for general axisymmetric objects

NASA Astrophysics Data System (ADS)

Fukushima, Toshio

2016-10-01

We developed a numerical method to compute the gravitational field of a general axisymmetric object. The method (I) numerically evaluates a double integral of the ring potential by the split quadrature method using the double exponential rules, and (II) derives the acceleration vector by numerically differentiating the numerically integrated potential by Ridder's algorithm. Numerical comparison with the analytical solutions for a finite uniform spheroid and an infinitely extended object of the Miyamoto-Nagai density distribution confirmed the 13- and 11-digit accuracy of the potential and the acceleration vector computed by the method, respectively. By using the method, we present the gravitational potential contour map and/or the rotation curve of various axisymmetric objects: (I) finite uniform objects covering rhombic spindles and circular toroids, (II) infinitely extended spheroids including Sérsic and Navarro-Frenk-White spheroids, and (III) other axisymmetric objects such as an X/peanut-shaped object like NGC 128, a power-law disc with a central hole like the protoplanetary disc of TW Hya, and a tear-drop-shaped toroid like an axisymmetric equilibrium solution of plasma charge distribution in an International Thermonuclear Experimental Reactor-like tokamak. The method is directly applicable to the electrostatic field and will be easily extended for the magnetostatic field. The FORTRAN 90 programs of the new method and some test results are electronically available.

Planet-disc interaction in laminar and turbulent discs

NASA Astrophysics Data System (ADS)

Stoll, Moritz H. R.; Picogna, Giovanni; Kley, Wilhelm

2017-07-01

In weakly ionised discs turbulence can be generated through the vertical shear instability (VSI). Embedded planets are affected by a stochastic component in the torques acting on them, which can impact their migration. In this work we study the interplay between a growing planet embedded in a protoplanetary disc and the VSI turbulence. We performed a series of 3D hydrodynamical simulations for locally isothermal discs with embedded planets in the mass range from 5 to 100 Earth masses. We study planets embedded in an inviscid disc that is VSI unstable, becomes turbulent, and generates angular momentum transport with an effective α = 5 × 10-4. This is compared to the corresponding viscous disc using exactly this α-value. In general we find that the planets have only a weak impact on the disc turbulence. Only for the largest planet (100 M⊕) does the turbulent activity become enhanced inside of the planet. The depth and width of a gap created by the more massive planets (30,100 M⊕) in the turbulent disc equal exactly that of the corresponding viscous case, leading to very similar torque strengths acting on the planet, with small stochastic fluctuations for the VSI disc. At the gap edges vortices are generated that are stronger and longer-lived in the VSI disc. Low mass planets (with Mp ≤ 10 M⊕) do not open gaps in the disc in either case, but generate for the turbulent disc an overdensity behind the planet that exerts a significant negative torque. This can boost the inward migration in VSI turbulent discs well above the Type I rate. Owing to the finite turbulence level in realistic 3D discs the gap depth will always be limited and migration will not stall in inviscid discs.

Kinematics of a selectively constrained radiolucent anterior lumbar disc: comparisons to hybrid and circumferential fusion.

PubMed

Daftari, Tapan K; Chinthakunta, Suresh R; Ingalhalikar, Aditya; Gudipally, Manasa; Hussain, Mir; Khalil, Saif

2012-10-01

Despite encouraging clinical outcomes of one-level total disc replacements reported in literature, there is no compelling evidence regarding the stability following two-level disc replacement and hybrid constructs. The current study is aimed at evaluating the multidirectional kinematics of a two-level disc arthroplasty and hybrid construct with disc replacement adjacent to rigid circumferential fusion, compared to two-level fusion using a novel selectively constrained radiolucent anterior lumbar disc. Nine osteoligamentous lumbosacral spines (L1-S1) were tested in the following sequence: 1) Intact; 2) One-level disc replacement; 3) Hybrid; 4) Two-level disc replacement; and 5) Two-level fusion. Range of motion (at both implanted and adjacent level), and center of rotation in sagittal plane were recorded and calculated. At the level of implantation, motion was restored when one-level disc replacement was used but tended to decrease with two-level disc arthroplasty. The findings also revealed that both one-level and two-level disc replacement and hybrid constructs did not significantly change adjacent level kinematics compared to the intact condition, whereas the two-level fusion construct demonstrated a significant increase in flexibility at the adjacent level. The location of center of rotation in the sagittal plane at L4-L5 for the one-level disc replacement construct was similar to that of the intact condition. The one-level disc arthroplasty tended to mimic a motion profile similar to the intact spine. However, the two-level disc replacement construct tended to reduce motion and clinical stability of a two-level disc arthroplasty requires additional investigation. Hybrid constructs may be used as a surgical alternative for treating two-level lumbar degenerative disc disease. Published by Elsevier Ltd.

Polar alignment of a protoplanetary disc around an eccentric binary II: Effect of binary and disc parameters

NASA Astrophysics Data System (ADS)

Martin, Rebecca G.; Lubow, Stephen H.

2018-06-01

In a recent paper Martin & Lubow showed that a circumbinary disc around an eccentric binary can undergo damped nodal oscillations that lead to the polar (perpendicular) alignment of the disc relative to the binary orbit. The disc angular momentum vector aligns to the eccentricity vector of the binary. We explore the robustness of this mechanism for a low mass disc (0.001 of the binary mass) and its dependence on system parameters by means of hydrodynamic disc simulations. We describe how the evolution depends upon the disc viscosity, temperature, size, binary mass ratio, orbital eccentricity and inclination. We compare results with predictions of linear theory. We show that polar alignment of a low mass disc may occur over a wide range of binary-disc parameters. We discuss the application of our results to the formation of planetary systems around eccentric binary stars.

Proto-planetary disc evolution and dispersal

NASA Astrophysics Data System (ADS)

Rosotti, Giovanni Pietro

2015-05-01

Planets form from gas and dust discs in orbit around young stars. The timescale for planet formation is constrained by the lifetime of these discs. The properties of the formed planetary systems depend thus on the evolution and final dispersal of the discs, which is the main topic of this thesis. Observations reveal the existence of a class of discs called "transitional", which lack dust in their inner regions. They are thought to be the last stage before the complete disc dispersal, and hence they may provide the key to understanding the mechanisms behind disc evolution. X-ray photoevaporation and planet formation have been studied as possible physical mechanisms responsible for the final dispersal of discs. However up to now, these two phenomena have been studied separately, neglecting any possible feedback or interaction. In this thesis we have investigated what is the interplay between these two processes. We show that the presence of a giant planet in a photo-evaporating disc can significantly shorten its lifetime, by cutting the inner regions from the mass reservoir in the exterior of the disc. This mechanism produces transition discs that for a given mass accretion rate have larger holes than in models considering only X-ray photo-evaporation, constituting a possible route to the formation of accreting transition discs with large holes. These discs are found in observations and still constitute a puzzle for the theory. Inclusion of the phenomenon called "thermal sweeping", a violent instability that can destroy a whole disc in as little as 10 4 years, shows that the outer disc left can be very short-lived (depending on the X-ray luminosity of the star), possibly explaining why very few non accreting transition discs are observed. However the mechanism does not seem to be efficient enough to reconcile with observations. In this thesis we also show that X-ray photo-evaporation naturally explains the observed correlation between stellar masses and accretion rates and is therefore the ideal candidate for driving disc evolution. Another process that can influence discs is a close encounter with another star. In this thesis we develop a model to study the effect of stellar dynamics in the natal stellar cluster on the discs, following for the first time at the same time the stellar dynamics together with the evolution of the discs. We find that, although close encounters with stars are unlikely to change significantly the mass of a disc, they can change substantially its size, hence imposing an upper limit on the observed disc radii. Finally, we investigated in this thesis whether discs can be reformed after their dispersal. If a star happens to be in a region that is currently forming stars, it can accrete material from the interstellar medium. This mechanism may result in the production of "second generation" discs such that in a given star forming region a few percent of stars may still possess a disc, in tentative agreement with observations of so called "old accretors", which are difficult to explain within the current paradigm of disc evolution and dispersal.

SU-C-209-07: Phantoms for Digital Breast Tomosynthesis Imaging System Evaluation

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

Jacobson, D; Liu, Y

2016-06-15

Purpose: Digital Breast Tomosynthesis (DBT) is gaining importance in breast imaging. There is a need for phantoms that can be used for image evaluation and comparison. Existing commercially available phantoms for DBT are expensive and may lack clinically relevant test objects. The purpose of this study is to develop phantoms for DBT evaluation. Methods Four phantoms have been designed and constructed to assess the image quality (IQ) of two DBT systems. The first contains a spiral of 0.3 mm SiC beads in gelatin to measure the tomographic slice thickness profile and uniformity of coverage in a series of tomographic planes.more » The second contains simulated tumors inclined with respect to the phantom base to assess tomographic image quality. The third has a tilted array of discs with varying contrast and diameter. This phantom was imaged alone and in a stack of TE slabs giving 2 to 10 cm thickness. The fourth has a dual wedge of glandular and adipose simulating materials. One wedge contains discs with varying diameter and thickness; the other supports a mass with six simulated spicules of varying size and a cluster of simulated calcifications. The simulated glandular tissue material varies between 35 and 100% of the total thickness (5.5 cm). Results: All phantoms were scanned successfully. The best IQ comparison was achieved with the dual wedge phantom as demonstrated by the spiculated mass and calcifications. Images were evaluated by two radiologists and one physicist. The projection images and corresponding set of tomographic planes were comparable and the synthesized projection images were inferior to the projection images for both systems. Conclusion: Four phantoms were designed, constructed and imaged on two DBT systems. They successfully demonstrated performance differences between two systems, and between true and synthesized projection images. Future work will incorporate these designs into a single phantom.« less

3D-printing zirconia implants; a dream or a reality? An in-vitro study evaluating the dimensional accuracy, surface topography and mechanical properties of printed zirconia implant and discs.

PubMed

Osman, Reham B; van der Veen, Albert J; Huiberts, Dennis; Wismeijer, Daniel; Alharbi, Nawal

2017-11-01

The aim of this study was to evaluate the dimensional accuracy, surface topography of a custom designed, 3D-printed zirconia dental implant and the mechanical properties of printed zirconia discs. A custom designed implant was 3D-printed in zirconia using digital light processing technique (DLP). The dimensional accuracy was assessed using the digital-subtraction technique. The mechanical properties were evaluated using biaxial flexure strength test. Three different build angles were adopted to print the specimens for the mechanical test; 0°(Vertical), 45° (Oblique) and 90°(Horizontal) angles. The surface topography, crystallographic phase structure and surface roughness were evaluated using scanning electron microscopy analysis (SEM), X-ray diffractometer and confocal microscopy respectively. The printed implant was dimensionally accurate with a root mean square (RMSE) value of 0.1mm. The Weibull analysis revealed a statistically significant higher characteristic strength (1006.6MPa) of 0° printed specimens compared to the other two groups and no significant difference between 45° (892.2MPa) and 90° (866.7MPa) build angles. SEM analysis revealed cracks, micro-porosities and interconnected pores ranging in size from 196nm to 3.3µm. The mean Ra (arithmetic mean roughness) value of 1.59µm (±0.41) and Rq (root mean squared roughness) value of 1.94µm (±0.47) was found. A crystallographic phase of primarily tetragonal zirconia typical of sintered Yttria tetragonal stabilized zirconia (Y-TZP) was detected. DLP prove to be efficient for printing customized zirconia dental implants with sufficient dimensional accuracy. The mechanical properties showed flexure strength close to those of conventionally produced ceramics. Optimization of the 3D-printing process parameters is still needed to improve the microstructure of the printed objects. Copyright © 2017 Elsevier Ltd. All rights reserved.

Orbital alignment of circumbinary planets that form in misaligned circumbinary discs: the case of Kepler-413b

NASA Astrophysics Data System (ADS)

Pierens, A.; Nelson, R. P.

2018-06-01

Although most of the circumbinary planets detected by the Kepler spacecraft are on orbits that are closely aligned with the binary orbital plane, the systems Kepler-413 and Kepler-453 exhibit small misalignments of ˜2.5°. One possibility is that these planets formed in a circumbinary disc whose midplane was inclined relative to the binary orbital plane. Such a configuration is expected to lead to a warped and twisted disc, and our aim is to examine the inclination evolution of planets embedded in these discs. We employed 3D hydrodynamical simulations that examine the disc response to the presence of a modestly inclined binary with parameters that match the Kepler-413 system, as a function of disc parameters and binary inclinations. The discs all develop slowly varying warps, and generally display very small amounts of twist. Very slow solid body precession occurs because a large outer disc radius is adopted. Simulations of planets embedded in these discs resulted in the planet aligning with the binary orbit plane for disc masses close to the minimum mass solar nebular, such that nodal precession of the planet was controlled by the binary. For higher disc masses, the planet maintains near coplanarity with the local disc midplane. Our results suggest that circumbinary planets born in tilted circumbinary discs should align with the binary orbit plane as the disc ages and loses mass, even if the circumbinary disc remains misaligned from the binary orbit. This result has important implications for understanding the origins of the known circumbinary planets.

DStat: A Versatile, Open-Source Potentiostat for Electroanalysis and Integration.

PubMed

Dryden, Michael D M; Wheeler, Aaron R

2015-01-01

Most electroanalytical techniques require the precise control of the potentials in an electrochemical cell using a potentiostat. Commercial potentiostats function as "black boxes," giving limited information about their circuitry and behaviour which can make development of new measurement techniques and integration with other instruments challenging. Recently, a number of lab-built potentiostats have emerged with various design goals including low manufacturing cost and field-portability, but notably lacking is an accessible potentiostat designed for general lab use, focusing on measurement quality combined with ease of use and versatility. To fill this gap, we introduce DStat (http://microfluidics.utoronto.ca/dstat), an open-source, general-purpose potentiostat for use alone or integrated with other instruments. DStat offers picoampere current measurement capabilities, a compact USB-powered design, and user-friendly cross-platform software. DStat is easy and inexpensive to build, may be modified freely, and achieves good performance at low current levels not accessible to other lab-built instruments. In head-to-head tests, DStat's voltammetric measurements are much more sensitive than those of "CheapStat" (a popular open-source potentiostat described previously), and are comparable to those of a compact commercial "black box" potentiostat. Likewise, in head-to-head tests, DStat's potentiometric precision is similar to that of a commercial pH meter. Most importantly, the versatility of DStat was demonstrated through integration with the open-source DropBot digital microfluidics platform. In sum, we propose that DStat is a valuable contribution to the "open source" movement in analytical science, which is allowing users to adapt their tools to their experiments rather than alter their experiments to be compatible with their tools.

DStat: A Versatile, Open-Source Potentiostat for Electroanalysis and Integration

PubMed Central

Dryden, Michael D. M.; Wheeler, Aaron R.

2015-01-01

Most electroanalytical techniques require the precise control of the potentials in an electrochemical cell using a potentiostat. Commercial potentiostats function as “black boxes,” giving limited information about their circuitry and behaviour which can make development of new measurement techniques and integration with other instruments challenging. Recently, a number of lab-built potentiostats have emerged with various design goals including low manufacturing cost and field-portability, but notably lacking is an accessible potentiostat designed for general lab use, focusing on measurement quality combined with ease of use and versatility. To fill this gap, we introduce DStat (http://microfluidics.utoronto.ca/dstat), an open-source, general-purpose potentiostat for use alone or integrated with other instruments. DStat offers picoampere current measurement capabilities, a compact USB-powered design, and user-friendly cross-platform software. DStat is easy and inexpensive to build, may be modified freely, and achieves good performance at low current levels not accessible to other lab-built instruments. In head-to-head tests, DStat’s voltammetric measurements are much more sensitive than those of “CheapStat” (a popular open-source potentiostat described previously), and are comparable to those of a compact commercial “black box” potentiostat. Likewise, in head-to-head tests, DStat’s potentiometric precision is similar to that of a commercial pH meter. Most importantly, the versatility of DStat was demonstrated through integration with the open-source DropBot digital microfluidics platform. In sum, we propose that DStat is a valuable contribution to the “open source” movement in analytical science, which is allowing users to adapt their tools to their experiments rather than alter their experiments to be compatible with their tools. PMID:26510100

Audiovisual Bounce-Inducing Effect: Attention Alone Does Not Explain Why the Discs Are Bouncing

ERIC Educational Resources Information Center

Grassi, Massimo; Casco, Clara

2009-01-01

Two discs moving from opposite points in space, overlapping and stopping at the other disc's starting point, can be seen as either bouncing or streaming through each other. With silent displays, observers report the discs as streaming, whereas if a sound is played when the discs touch each other, observers report the discs as bouncing. The origin…

Reduction of turbulent skin-friction drag by oscillating discs

NASA Astrophysics Data System (ADS)

Wise, Daniel; Ricco, Pierre

2013-11-01

A new drag-reduction method, based on the active technique proposed by Ricco & Hahn (2013), i.e. steadily rotating flush-mounted discs, is studied by DNS. The effect of sinusoidally oscillating discs on the turbulent channel-flow drag is investigated at Reτ = 180 , based on the friction velocity of the stationary-wall case and the half channel height. A parametric investigation on the disc diameter, tip velocity and oscillation period yielded a maximum drag reduction of 18.5%. Regions of net power saved, calculated by considering the power spent to enforce the disc motion against the viscous resistance of the fluid, are found to reach up to 6.5% for low disc tip velocities. Significantly, the characteristic time-scale for the oscillating disc forcing is double that for the steadily rotating discs, representing a further step towards industrial implementation. The oscillating disc forcing, similar to the steadily rotating disc forcing, creates streamwise-elongated structures between the discs. These structures - largely unaffected by the periodic wall forcing and persisting throughout the entire period of the oscillation - are the main contributor to the additional Reynolds stresses term created by the disc forcing, and are important for the drag reduction mechanism.

Formation of neuronal pathways in the imaginal discs of Drosophila melanogaster.

PubMed

Jan, Y N; Ghysen, A; Christoph, I; Barbel, S; Jan, L Y

1985-09-01

We have followed the formation of neuronal pathways in different imaginal discs of Drosophila. The pattern is highly reproducible for a given disc type but distinct for each type of discs: in leg discs, several neurons are present before metamorphosis and provide two major pathways that are joined by later neurons; in the wing and haltere discs, a few pairs of neurons appear after the onset of metamorphosis and pioneer the major pathways; in antenna discs, no pioneers are detected before massive neuronal differentiation begins. The mechanisms used for axonal guidance seem common to all discs, and the differences between discs can be accounted for simply by differences in the arrangement and birth time of pioneer neurons. Different subsets of pioneer neurons are deleted by mutations such as scute and engrailed.

Field-based Digital Mapping of the November 3, 2002 Susitna Glacier Fault Rupture - Integrating remotely sensed data, GIS, and photo-linking technologies

NASA Astrophysics Data System (ADS)

Staft, L. A.; Craw, P. A.

2003-12-01

In July 2003, the U.S. Geological Survey and the Alaska Division of Geological & Geophysical Surveys (DGGS) conducted field studies on the Susitna Glacier Fault (SGF), which ruptured on November 2002 during the M 7.9 Denali fault earthquake. The DGGS assumed responsibility for Geographic Information System (GIS) and data management, integrating remotely sensed imagery, GPS data, GIS, and photo-linking software to aid in planning and documentation of fieldwork. Pre-field preparation included acquisition of over 150, 1:6,000-scale true-color aerial photographs taken shortly after the SGF rupture, 1:63,360-scale color-infrared (CIR) 1980 aerial photographs, and digital geographic information including a 15-minute Digital Elevation Model (DEM), 1:63,360-scale Digital Raster Graphics (DRG), and LandSat 7 satellite imagery. Using Orthomapper software, we orthorectified and mosaiced seven CIRs, creating a georeferenced, digital photo base of the study area. We used this base to reference the 1:6,000-scale aerial photography, to view locations of field sites downloaded from GPS, and to locate linked digital photographs that were taken in the field. Photos were linked using GPS-Photo Link software which "links" digital photographs to GPS data by correlating time stamps from the GPS track log or waypoint file to those of the digital photos, using the correlated point data to create a photo location ESRI shape file. When this file is opened in ArcMap or ArcView with the GPS-Photo Link utility enabled, a thumbnail image of the linked photo appears when the cursor is over the photo location. Viewing photographed features and scarp-profile locations in GIS allowed us to evaluate data coverage of the rupture daily. Using remotely sensed imagery in the field with GIS gave us the versatility to display data on a variety of bases, including topographic maps, air photos, and satellite imagery, during fieldwork. In the field, we downloaded, processed, and reviewed data as it was collected, taking major steps toward final digital map production. Using the described techniques greatly enhanced our ability to analyze and interpret field data; the resulting digital data structure allows us to efficiently gather, disseminate, and archive critical field data.

The relationship between quantitative measures of disc height and disc signal intensity with Pfirrmann score of disc degeneration.

PubMed

Salamat, Sara; Hutchings, John; Kwong, Clemens; Magnussen, John; Hancock, Mark J

2016-01-01

To assess the relationship between quantitative measures of disc height and signal intensity with the Pfirrmann disc degeneration scoring system and to test the inter-rater reliability of the quantitative measures. Participants were 76 people who had recently recovered from their last episode of acute low back pain and underwent MRI scan on a single 3T machine. At all 380 lumbar discs, quantitative measures of disc height and signal intensity were made by 2 independent raters and compared to Pfirrmann scores from a single radiologist. For quantitative measures of disc height and signal intensity a "raw" score and 2 adjusted ratios were calculated and the relationship with Pfirrmann scores was assessed. The inter-tester reliability of quantitative measures was also investigated. There was a strong linear relationship between quantitative disc signal intensity and Pfirrmann scores for grades 1-4, but not for grades 4 and 5. For disc height only, Pfirrmann grade 5 had significantly reduced disc height compared to all other grades. Results were similar regardless of whether raw or adjusted scores were used. Inter-rater reliability for the quantitative measures was excellent (ICC > 0.97). Quantitative measures of disc signal intensity were strongly related to Pfirrmann scores from grade 1 to 4; however disc height only differentiated between grade 4 and 5 Pfirrmann scores. Using adjusted ratios for quantitative measures of disc height or signal intensity did not significantly alter the relationship with Pfirrmann scores.

Effects of disc mid-plane evolution on CO snowline location

NASA Astrophysics Data System (ADS)

Panić, O.; Min, M.

2017-05-01

Temperature changes in the planet forming disc mid-planes carry important physico-chemical consequences, such as the effect on the locations of the condensation fronts of molecules - the snowlines. Snowlines impose major chemical gradients and possibly foster grain growth. The aim of this paper is to understand how disc mid-plane temperature changes with gas and dust evolution, and identify trends that may influence planet formation or allow to constrain disc evolution observationally. We calculate disc temperature, hydrostatic equilibrium and dust settling in a mutually consistent way from a grid of disc models at different stages of gas loss, grain growth and hole opening. We find that the CO snowline location depends very strongly on disc properties. The CO snowline location migrates closer to the star for increasing degrees of gas dispersal and dust growth. Around a typical A-type star, the snowline can be anywhere between several tens and a few hundred au, depending on the disc properties such as gas mass and grain size. In fact, gas loss is as efficient as dust evolution in settling discs, and flat discs may be gas-poor counterparts of flared discs. Our results, in the context of different pre-main-sequence evolution of the luminosity in low- and intermediate-mass stars suggest very different thermal (and hence chemical) histories in these two types of discs. Discs of T Tauri stars settle and cool down, while discs of Herbig Ae stars may remain rather warm throughout the pre-main sequence.

Kozai-Lidov disc instability

NASA Astrophysics Data System (ADS)

Lubow, Stephen H.; Ogilvie, Gordon I.

2017-08-01

Recent results by Martin et al. showed in 3D smoothed particle hydrodynamics simulations that tilted discs in binary systems can be unstable to the development of global, damped Kozai-Lidov (KL) oscillations in which the discs exchange tilt for eccentricity. We investigate the linear stability of KL modes for tilted inviscid discs under the approximations that the disc eccentricity is small and the disc remains flat. By using 1D equations, we are able to probe regimes of large ratios of outer to inner disc edge radii that are realistic for binary systems of hundreds of astronomical unit separations and are not easily probed by multidimensional simulations. For order unity binary mass ratios, KL instability is possible for a window of disc aspect ratios H/r in the outer parts of a disc that roughly scale as (nb/n)2 ≲ H/r ≲ nb/n, for binary orbital frequency nb and orbital frequency n at the disc outer edge. We present a framework for understanding the zones of instability based on the determination of branches of marginally unstable modes. In general, multiple growing eccentric KL modes can be present in a disc. Coplanar apsidal-nodal precession resonances delineate instability branches. We determine the range of tilt angles for unstable modes as a function of disc aspect ratio. Unlike the KL instability for free particles that involves a critical (minimum) tilt angle, disc instability is possible for any non-zero tilt angle depending on the disc aspect ratio.

MOSAIC: Software for creating mosaics from collections of images

NASA Technical Reports Server (NTRS)

Varosi, F.; Gezari, D. Y.

1992-01-01

We have developed a powerful, versatile image processing and analysis software package called MOSAIC, designed specifically for the manipulation of digital astronomical image data obtained with (but not limited to) two-dimensional array detectors. The software package is implemented using the Interactive Data Language (IDL), and incorporates new methods for processing, calibration, analysis, and visualization of astronomical image data, stressing effective methods for the creation of mosaic images from collections of individual exposures, while at the same time preserving the photometric integrity of the original data. Since IDL is available on many computers, the MOSAIC software runs on most UNIX and VAX workstations with the X-Windows or Sun View graphics interface.

DBSAR's First Multimode Flight Campaign

NASA Technical Reports Server (NTRS)

Rincon, Rafael F.; Vega, Manuel; Buenfil, Manuel; Geist, Alessandro; Hilliard, Lawrence; Racette, Paul

2010-01-01

The Digital Beamforming SAR (DBSAR) is an airborne imaging radar system that combines phased array technology, reconfigurable on-board processing and waveform generation, and advances in signal processing to enable techniques not possible with conventional SARs. The system exploits the versatility inherently in phased-array technology with a state-of-the-art data acquisition and real-time processor in order to implement multi-mode measurement techniques in a single radar system. Operational modes include scatterometry over multiple antenna beams, Synthetic Aperture Radar (SAR) over several antenna beams, or Altimetry. The radar was flight tested in October 2008 on board of the NASA P3 aircraft over the Delmarva Peninsula, MD. The results from the DBSAR system performance is presented.

Vacuum compatible miniature CCD camera head

DOEpatents

Conder, Alan D.

2000-01-01

A charge-coupled device (CCD) camera head which can replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating x-rays, such as within a target chamber where laser produced plasmas are studied. The camera head is small, capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, which allows for close(0.04" for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high energy density plasmas, for a variety of military industrial, and medical imaging applications.

Nanoporous hard data: optical encoding of information within nanoporous anodic alumina photonic crystals

NASA Astrophysics Data System (ADS)

Santos, Abel; Law, Cheryl Suwen; Pereira, Taj; Losic, Dusan

2016-04-01

Herein, we present a method for storing binary data within the spectral signature of nanoporous anodic alumina photonic crystals. A rationally designed multi-sinusoidal anodisation approach makes it possible to engineer the photonic stop band of nanoporous anodic alumina with precision. As a result, the transmission spectrum of these photonic nanostructures can be engineered to feature well-resolved and selectively positioned characteristic peaks across the UV-visible spectrum. Using this property, we implement an 8-bit binary code and assess the versatility and capability of this system by a series of experiments aiming to encode different information within the nanoporous anodic alumina photonic crystals. The obtained results reveal that the proposed nanosized platform is robust, chemically stable, versatile and has a set of unique properties for data storage, opening new opportunities for developing advanced nanophotonic tools for a wide range of applications, including sensing, photonic tagging, self-reporting drug releasing systems and secure encoding of information.Herein, we present a method for storing binary data within the spectral signature of nanoporous anodic alumina photonic crystals. A rationally designed multi-sinusoidal anodisation approach makes it possible to engineer the photonic stop band of nanoporous anodic alumina with precision. As a result, the transmission spectrum of these photonic nanostructures can be engineered to feature well-resolved and selectively positioned characteristic peaks across the UV-visible spectrum. Using this property, we implement an 8-bit binary code and assess the versatility and capability of this system by a series of experiments aiming to encode different information within the nanoporous anodic alumina photonic crystals. The obtained results reveal that the proposed nanosized platform is robust, chemically stable, versatile and has a set of unique properties for data storage, opening new opportunities for developing advanced nanophotonic tools for a wide range of applications, including sensing, photonic tagging, self-reporting drug releasing systems and secure encoding of information. Electronic supplementary information (ESI) available: Further details about anodisation profiles, SEM cross-section images, digital pictures, transmission spectra, photonic barcodes and ASCII codes of the different NAA photonic crystals fabricated and analysed in our study. See DOI: 10.1039/c6nr01068g

Liquid-film electron stripper

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

Gavin, B.F.

1986-12-02

This patent describes an improved liquid-film electron stripper for high intensity heavy ion beams comprising: at least one rotatable disc mounted in a housing, means for rotating the disc, a liquid reservoir operatively connected to the housing, means for directing liquid from the reservoir onto the rotatable disc for forming a film of liquid as liquid is spun from the disc, the disc being configured to define a sharp edge located at one side of the periphery of the disc, and configured to include a flat, smooth radially outer section located adjacent the sharp edge, the liquid being directed ontomore » the flat, smooth section of the disc, the means for directing liquid onto the disc including a nozzle positioned with respect to the disc so that liquid from the nozzle impinges at about a 90/sup 0/ angle with respect to the flat, smooth surface of the disc, and liquid film terminator means located in spaced relation to the disc and approximately perpendicular to a formed liquid film, the terminator means comprising at least one ribbon of material secured to the housing.« less

In Vitro Maturation and In Vivo Integration and Function of an Engineered Cell-Seeded Disc-like Angle Ply Structure (DAPS) for Total Disc Arthroplasty.

PubMed

Martin, J T; Gullbrand, S E; Kim, D H; Ikuta, K; Pfeifer, C G; Ashinsky, B G; Smith, L J; Elliott, D M; Smith, H E; Mauck, R L

2017-11-17

Total disc replacement with an engineered substitute is a promising avenue for treating advanced intervertebral disc disease. Toward this goal, we developed cell-seeded disc-like angle ply structures (DAPS) and showed through in vitro studies that these constructs mature to match native disc composition, structure, and function with long-term culture. We then evaluated DAPS performance in an in vivo rat model of total disc replacement; over 5 weeks in vivo, DAPS maintained their structure, prevented intervertebral bony fusion, and matched native disc mechanical function at physiologic loads in situ. However, DAPS rapidly lost proteoglycan post-implantation and did not integrate into adjacent vertebrae. To address this, we modified the design to include polymer endplates to interface the DAPS with adjacent vertebrae, and showed that this modification mitigated in vivo proteoglycan loss while maintaining mechanical function and promoting integration. Together, these data demonstrate that cell-seeded engineered discs can replicate many characteristics of the native disc and are a viable option for total disc arthroplasty.

Rethinking Black Hole Accretion Discs

NASA Astrophysics Data System (ADS)

Salvesen, Greg

Accretion discs are staples of astrophysics. Tapping into the gravitational potential energy of the accreting material, these discs are highly efficient machines that produce copious radiation and extreme outflows. While interesting in their own right, accretion discs also act as tools to study black holes and directly influence the properties of the Universe. Black hole X-ray binaries are fantastic natural laboratories for studying accretion disc physics and black hole phenomena. Among many of the curious behaviors exhibited by these systems are black hole state transitions -- complicated cycles of dramatic brightening and dimming. Using X-ray observations with high temporal cadence, we show that the evolution of the accretion disc spectrum during black hole state transitions can be described by a variable disc atmospheric structure without invoking a radially truncated disc geometry. The accretion disc spectrum can be a powerful diagnostic for measuring black hole spin if the effects of the disc atmosphere on the emergent spectrum are well-understood; however, properties of the disc atmosphere are largely unconstrained. Using statistical methods, we decompose this black hole spin measurement technique and show that modest uncertainties regarding the disc atmosphere can lead to erroneous spin measurements. The vertical structure of the disc is difficult to constrain due to our ignorance of the contribution to hydrostatic balance by magnetic fields, which are fundamental to the accretion process. Observations of black hole X-ray binaries and the accretion environments near supermassive black holes provide mounting evidence for strong magnetization. Performing numerical simulations of accretion discs in the shearing box approximation, we impose a net vertical magnetic flux that allows us to effectively control the level of disc magnetization. We study how dynamo activity and the properties of turbulence driven by the magnetorotational instability depend on the magnetized state of the gas, spanning weak-to-strong disc magnetization regimes. We also demonstrate that a background poloidal magnetic flux is required to form and sustain a strongly magnetized accretion disc. This thesis motivates the need for understanding how magnetic fields affect the observed spectrum from black hole accretion discs.

Ensuring long-term reliability of the data storage on optical disc

NASA Astrophysics Data System (ADS)

Chen, Ken; Pan, Longfa; Xu, Bin; Liu, Wei

2008-12-01

"Quality requirements and handling regulation of archival optical disc for electronic records filing" is released by The State Archives Administration of the People's Republic of China (SAAC) on its network in March 2007. This document established a complete operative managing process for optical disc data storage in archives departments. The quality requirements of the optical disc used in archives departments are stipulated. Quality check of the recorded disc before filing is considered to be necessary and the threshold of the parameter of the qualified filing disc is set down. The handling regulations for the staffs in the archives departments are described. Recommended environment conditions of the disc preservation, recording, accessing and testing are presented. The block error rate of the disc is selected as main monitoring parameter of the lifetime of the filing disc and three classes pre-alarm lines are created for marking of different quality check intervals. The strategy of monitoring the variation of the error rate curve of the filing discs and moving the data to a new disc or a new media when the error rate of the disc reaches the third class pre-alarm line will effectively guarantee the data migration before permanent loss. Only when every step of the procedure is strictly implemented, it is believed that long-term reliability of the data storage on optical disc for archives departments can be effectively ensured.

How do accretion discs break?

NASA Astrophysics Data System (ADS)

Dogan, Suzan

2016-07-01

Accretion discs are common in binary systems, and they are often found to be misaligned with respect to the binary orbit. The gravitational torque from a companion induces nodal precession in misaligned disc orbits. In this study, we first calculate whether this precession is strong enough to overcome the internal disc torques communicating angular momentum. We compare the disc precession torque with the disc viscous torque to determine whether the disc should warp or break. For typical parameters precession wins: the disc breaks into distinct planes that precess effectively independently. To check our analytical findings, we perform 3D hydrodynamical numerical simulations using the PHANTOM smoothed particle hydrodynamics code, and confirm that disc breaking is widespread and enhances accretion on to the central object. For some inclinations, the disc goes through strong Kozai cycles. Disc breaking promotes markedly enhanced and variable accretion and potentially produces high-energy particles or radiation through shocks. This would have significant implications for all binary systems: e.g. accretion outbursts in X-ray binaries and fuelling supermassive black hole (SMBH) binaries. The behaviour we have discussed in this work is relevant to a variety of astrophysical systems, for example X-ray binaries, where the disc plane may be tilted by radiation warping, SMBH binaries, where accretion of misaligned gas can create effectively random inclinations and protostellar binaries, where a disc may be misaligned by a variety of effects such as binary capture/exchange, accretion after binary formation.

Notochord Cells in Intervertebral Disc Development and Degeneration

PubMed Central

McCann, Matthew R.; Séguin, Cheryle A.

2016-01-01

The intervertebral disc is a complex structure responsible for flexibility, multi-axial motion, and load transmission throughout the spine. Importantly, degeneration of the intervertebral disc is thought to be an initiating factor for back pain. Due to a lack of understanding of the pathways that govern disc degeneration, there are currently no disease-modifying treatments to delay or prevent degenerative disc disease. This review presents an overview of our current understanding of the developmental processes that regulate intervertebral disc formation, with particular emphasis on the role of the notochord and notochord-derived cells in disc homeostasis and how their loss can result in degeneration. We then describe the role of small animal models in understanding the development of the disc and their use to interrogate disc degeneration and associated pathologies. Finally, we highlight essential development pathways that are associated with disc degeneration and/or implicated in the reparative response of the tissue that might serve as targets for future therapeutic approaches. PMID:27252900

Image is everything: pearls and pitfalls of digital photography and PowerPoint presentations for the cosmetic surgeon.

PubMed

Niamtu, Joseph

2004-01-01

Cosmetic surgery and photography are inseparable. Clinical photographs serve as diagnostic aids, medical records, legal protection, and marketing tools. In the past, taking high-quality, standardized images and maintaining and using them for presentations were tasks of significant proportion when done correctly. Although the cosmetic literature is replete with articles on standardized photography, this has eluded many practitioners in part to the complexity. A paradigm shift has occurred in the past decade, and digital technology has revolutionized clinical photography and presentations. Digital technology has made it easier than ever to take high-quality, standardized images and to use them in a multitude of ways to enhance the practice of cosmetic surgery. PowerPoint presentations have become the standard for academic presentations, but many pitfalls exist, especially when taking a backup disc to play on an alternate computer at a lecture venue. Embracing digital technology has a mild to moderate learning curve but is complicated by old habits and holdovers from the days of slide photography, macro lenses, and specialized flashes. Discussion is presented to circumvent common problems involving computer glitches with PowerPoint presentations. In the past, high-quality clinical photography was complex and sometimes beyond the confines of a busy clinical practice. The digital revolution of the past decade has removed many of these associated barriers, and it has never been easier or more affordable to take images and use them in a multitude of ways for learning, judging surgical outcomes, teaching and lecturing, and marketing. Even though this technology has existed for years, many practitioners have failed to embrace it for various reasons or fears. By following a few simple techniques, even the most novice practitioner can be on the forefront of digital imaging technology. By observing a number of modified techniques with digital cameras, any practitioner can take high-quality, standardized clinical photographs and can make and use these images to enhance his or her practice. This article deals with common pitfalls of digital photography and PowerPoint presentations and presents multiple pearls to achieve proficiency quickly with digital photography and imaging as well as avoid malfunction of PowerPoint presentations in an academic lecture venue.

Developing NanoFoil-Heated Thin-Film Thermal Battery

DTIC Science & Technology

2013-09-01

buffer discs (in gray) sandwiching the NanoFoil disc (in yellow). Two Microtherm discs (in dark gray) bracketed the sandwich to prevent excessive heat...of the fuse strip with a Microtherm disc. Cathode Electrolyte Anode Microtherm Heat paper NanoFoil Buffer Agilent 34970A 606.5 Nichrome wire Maccor...gray) sandwiching the NanoFoil disc (in yellow). Two Microtherm discs (in dark gray) bracketed the sandwich to prevent excessive heat loss

Is there any relationship between proinflammatory mediator levels in disc material and myelopathy with cervical disc herniation and spondylosis? A non-randomized, prospective clinical study

PubMed Central

Asir, Alparslan; Cetinkal, Ahmet; Gedik, Nursal; Kutlay, Ahmet Murat; Çolak, Ahmet; Kurtar, Sedat; Simsek, Hakan

2007-01-01

The proinflammatory mediator (PIM) levels were assessed in surgically removed samples of herniated cervical intervertebral discs. The objective of this study was to investigate if there is a correlation between the levels of PIMs in disc material and myelopathy associated with cervical intervertebral disc herniation and spondylosis. The role of proinflammatory mediators in the degeneration of intervertebral disc and the inflammatory effects of disc herniations on radicular pain has been previously published. However, the possible relationship between PIMs and myelopathy related to cervical disc herniation and spondylosis has not been investigated before. Thirty-two patients undergoing surgery for cervical disc herniation and spondylosis were investigated. Surgically obtained disc materials, stored at 70°C, were classified into two groups: cervical disc herniation alone or with myelopathy. Biochemical preparation and solid phase enzyme amplified sensitivity immunoassay (ELISIA) analysis of the samples were performed to assess the concentration of mediators in the samples. Very similar values of interleukin-6 were found in both groups whereas the concentrations of mediators were significantly higher in myelopathy group. This study has demonstrated that PIMs are involved in cervical intervertebral disc degeneration with higher concentrations in the samples associated with myelopathy. PMID:17476536

Effect of collagen fibre orientation on intervertebral disc torsion mechanics.

PubMed

Yang, Bo; O'Connell, Grace D

2017-12-01

The intervertebral disc is a complex fibro-cartilaginous material, consisting of a pressurized nucleus pulposus surrounded by the annulus fibrosus, which has an angle-ply structure. Disc injury and degeneration are noted by significant changes in tissue structure and function, which significantly alters stress distribution and disc joint stiffness. Differences in fibre orientation are thought to contribute to changes in disc torsion mechanics. Therefore, the objective of this study was to evaluate the effect of collagen fibre orientation on internal disc mechanics under compression combined with axial rotation. We developed and validated a finite element model (FEM) to delineate changes in disc mechanics due to fibre orientation from differences in material properties. FEM simulations were performed with fibres oriented at [Formula: see text] throughout the disc (uniform by region and fibre layer). The initial model was validated by published experimental results for two load conditions, including [Formula: see text] axial compression and [Formula: see text] axial rotation. Once validated, fibre orientation was rotated by [Formula: see text] or [Formula: see text] towards the horizontal plane, resulting in a decrease in disc joint torsional stiffness. Furthermore, we observed that axial rotation caused a sinusoidal change in disc height and radial bulge, which may be beneficial for nutrient transport. In conclusion, including anatomically relevant fibre angles in disc joint FEMs is important for understanding stress distribution throughout the disc and will be important for understanding potential causes for disc injury. Future models will include regional differences in fibre orientation to better represent the fibre architecture of the native disc.

Regression Analysis of Optical Coherence Tomography Disc Variables for Glaucoma Diagnosis.

PubMed

Richter, Grace M; Zhang, Xinbo; Tan, Ou; Francis, Brian A; Chopra, Vikas; Greenfield, David S; Varma, Rohit; Schuman, Joel S; Huang, David

2016-08-01

To report diagnostic accuracy of optical coherence tomography (OCT) disc variables using both time-domain (TD) and Fourier-domain (FD) OCT, and to improve the use of OCT disc variable measurements for glaucoma diagnosis through regression analyses that adjust for optic disc size and axial length-based magnification error. Observational, cross-sectional. In total, 180 normal eyes of 112 participants and 180 eyes of 138 participants with perimetric glaucoma from the Advanced Imaging for Glaucoma Study. Diagnostic variables evaluated from TD-OCT and FD-OCT were: disc area, rim area, rim volume, optic nerve head volume, vertical cup-to-disc ratio (CDR), and horizontal CDR. These were compared with overall retinal nerve fiber layer thickness and ganglion cell complex. Regression analyses were performed that corrected for optic disc size and axial length. Area-under-receiver-operating curves (AUROC) were used to assess diagnostic accuracy before and after the adjustments. An index based on multiple logistic regression that combined optic disc variables with axial length was also explored with the aim of improving diagnostic accuracy of disc variables. Comparison of diagnostic accuracy of disc variables, as measured by AUROC. The unadjusted disc variables with the highest diagnostic accuracies were: rim volume for TD-OCT (AUROC=0.864) and vertical CDR (AUROC=0.874) for FD-OCT. Magnification correction significantly worsened diagnostic accuracy for rim variables, and while optic disc size adjustments partially restored diagnostic accuracy, the adjusted AUROCs were still lower. Axial length adjustments to disc variables in the form of multiple logistic regression indices led to a slight but insignificant improvement in diagnostic accuracy. Our various regression approaches were not able to significantly improve disc-based OCT glaucoma diagnosis. However, disc rim area and vertical CDR had very high diagnostic accuracy, and these disc variables can serve to complement additional OCT measurements for diagnosis of glaucoma.

Gravitational Instabilities in a Protosolar-like Disc

NASA Astrophysics Data System (ADS)

Evans, Mark Graham

2018-02-01

This thesis presents a study of protoplanetary discs around young, low mass protostars. Such discs are believed to be massive enough to develop gravitational instabilities, which subsequently form spiral structures. The dynamical and chemical evolutions of a protosolar-like, gravitationally unstable disc are explored and the spiral structure in the disc is found to shock-heat material. This affects the chemical composition via enhanced desorption rates and endothermic reaction rates and through global mixing of the disc. As a result, the gravitational instability in the model disc leads to transient and permanent changes in the disc chemistry, and also provides a chemically-rich midplane in contrast to simulations of more evolved discs. Secondly, radiative transfer calculations are performed for the dust continuum, and model-tailored grid construction is found to improve the accuracy of the resultant flux images. Continuum observations of the model disc are synthesised and the spiral structure (driven by the gravitational instability) is shown to be readily detectable with ALMA across a range of frequencies, disc inclinations and dust opacities. The derivation of disc mass from the observed flux densities is explored but the method commonly utilised is found to be unreliable and underestimate the disc mass. Therefore, it is concluded that gravitational instabilities could be retrospectively validated in discs previously thought not massive enough to be self-gravitating. Finally, radiative transfer calculations are performed for molecular line transitions. Methods for improving the accuracy of line flux images are explored and the validity of assuming local thermodynamic equilibrium is assessed. Observations of the line fluxes are synthesised without noise and the spiral structure is found to be traced to an extent by all transitions considered, which is not necessarily congruent with the underlying distribution of the molecular species. The disc is seen in absorption in all transitions considered, due to the global mixing of the disc, which suggests absorption features could be a signature of gravitational instability in young protoplanetary discs. The sensitivities required to detect flux originating in spiral features are determined and it is found that a dedicated observation with ALMA should be capable of spatially resolving spiral structure in a Class 0 disc. Whether the spiral structure can be also be determined from spectral features is explored, which is shown to only be reliable with PV diagrams of nearly edge-on discs. The derivation of protostellar mass from PV diagrams is also explored and found to most likely be unreliable for gravitationally unstable discs.

A mobile device-based imaging spectrometer for environmental monitoring by attaching a lightweight small module to a commercial digital camera.

PubMed

Cai, Fuhong; Lu, Wen; Shi, Wuxiong; He, Sailing

2017-11-15

Spatially-explicit data are essential for remote sensing of ecological phenomena. Lately, recent innovations in mobile device platforms have led to an upsurge in on-site rapid detection. For instance, CMOS chips in smart phones and digital cameras serve as excellent sensors for scientific research. In this paper, a mobile device-based imaging spectrometer module (weighing about 99 g) is developed and equipped on a Single Lens Reflex camera. Utilizing this lightweight module, as well as commonly used photographic equipment, we demonstrate its utility through a series of on-site multispectral imaging, including ocean (or lake) water-color sensing and plant reflectance measurement. Based on the experiments we obtain 3D spectral image cubes, which can be further analyzed for environmental monitoring. Moreover, our system can be applied to many kinds of cameras, e.g., aerial camera and underwater camera. Therefore, any camera can be upgraded to an imaging spectrometer with the help of our miniaturized module. We believe it has the potential to become a versatile tool for on-site investigation into many applications.

A low power biomedical signal processor ASIC based on hardware software codesign.

PubMed

Nie, Z D; Wang, L; Chen, W G; Zhang, T; Zhang, Y T

2009-01-01

A low power biomedical digital signal processor ASIC based on hardware and software codesign methodology was presented in this paper. The codesign methodology was used to achieve higher system performance and design flexibility. The hardware implementation included a low power 32bit RISC CPU ARM7TDMI, a low power AHB-compatible bus, and a scalable digital co-processor that was optimized for low power Fast Fourier Transform (FFT) calculations. The co-processor could be scaled for 8-point, 16-point and 32-point FFTs, taking approximate 50, 100 and 150 clock circles, respectively. The complete design was intensively simulated using ARM DSM model and was emulated by ARM Versatile platform, before conducted to silicon. The multi-million-gate ASIC was fabricated using SMIC 0.18 microm mixed-signal CMOS 1P6M technology. The die area measures 5,000 microm x 2,350 microm. The power consumption was approximately 3.6 mW at 1.8 V power supply and 1 MHz clock rate. The power consumption for FFT calculations was less than 1.5 % comparing with the conventional embedded software-based solution.

High-Rate Digital Receiver Board

NASA Technical Reports Server (NTRS)

Ghuman, Parminder; Bialas, Thomas; Brambora, Clifford; Fisher, David

2004-01-01

A high-rate digital receiver (HRDR) implemented as a peripheral component interface (PCI) board has been developed as a prototype of compact, general-purpose, inexpensive, potentially mass-producible data-acquisition interfaces between telemetry systems and personal computers. The installation of this board in a personal computer together with an analog preprocessor enables the computer to function as a versatile, highrate telemetry-data-acquisition and demodulator system. The prototype HRDR PCI board can handle data at rates as high as 600 megabits per second, in a variety of telemetry formats, transmitted by diverse phase-modulation schemes that include binary phase-shift keying and various forms of quadrature phaseshift keying. Costing less than $25,000 (as of year 2003), the prototype HRDR PCI board supplants multiple racks of older equipment that, when new, cost over $500,000. Just as the development of standard network-interface chips has contributed to the proliferation of networked computers, it is anticipated that the development of standard chips based on the HRDR could contribute to reductions in size and cost and increases in performance of telemetry systems.

Integrated Digital Flight Control System for the Space Shuttle Orbiter

NASA Technical Reports Server (NTRS)

1973-01-01

The objectives of the integrated digital flight control system (DFCS) is to provide rotational and translational control of the space shuttle orbiter in all phases of flight: from launch ascent through orbit to entry and touchdown, and during powered horizontal flights. The program provides a versatile control system structure while maintaining uniform communications with other programs, sensors, and control effectors by using an executive routine/functional subroutine format. The program reads all external variables at a single point, copies them into its dedicated storage, and then calls the required subroutines in the proper sequence. As a result, the flight control program is largely independent of other programs in the computer complex and is equally insensitive to characteristics of the processor configuration. The integrated structure is described of the control system and the DFCS executive routine which embodies that structure. The input and output, including jet selection are included. Specific estimation and control algorithm are shown for the various mission phases: cruise (including horizontal powered flight), entry, on-orbit, and boost. Attitude maneuver routines that interface with the DFCS are included.

Enlivening Physics, a Local Video Disc Project.

ERIC Educational Resources Information Center

McInerney, M.

1989-01-01

Describes how to make and use an inexpensive video disc of physics demonstrations. Discusses the background, production of the disc, subject of the disc including angular momentum, "monkey and the hunter" experiment, Doppler shift, pressure of a constant volume of gas thermometer, and wave effects, and using the disc in classroom. (YP)

Dependence of optic disc parameters on disc area according to Heidelberg Retina Tomograph: Part II.

NASA Astrophysics Data System (ADS)

Machekhin, V.; Manaenkova, G.; Bondarenko, O.

2007-05-01

With the help of Heidelberg Retina Tomograph (HRT-II) optic disc parameters in 211 eyes of 115 healthy patients with refraction Em +/- 3,0 D and 96 eyes of 72 patients with myopia 3,5-14,0 D without any signs of glaucoma were studied. Analysis of optic disc parameters were carried out in 5 groups of patients according to disc area: less than 1,5 mm2, 1,5- 2,5 mm2, 2,5-3,0 mm2, 3,0-3,5 mm2 and more than 3,5 mm2. An accurate depending on disc area was revealed for all optic disc parameters in all sectors, which was manifested by increasing cup disc and rim disc (area and volume) and other parameters. We consider it is necessary to use the proper tables for right interpretation of received data for early diagnosis of glaucoma.

Automated volumetric evaluation of stereoscopic disc photography

PubMed Central

Xu, Juan; Ishikawa, Hiroshi; Wollstein, Gadi; Bilonick, Richard A; Kagemann, Larry; Craig, Jamie E; Mackey, David A; Hewitt, Alex W; Schuman, Joel S

2010-01-01

PURPOSE: To develop a fully automated algorithm (AP) to perform a volumetric measure of the optic disc using conventional stereoscopic optic nerve head (ONH) photographs, and to compare algorithm-produced parameters with manual photogrammetry (MP), scanning laser ophthalmoscope (SLO) and optical coherence tomography (OCT) measurements. METHODS: One hundred twenty-two stereoscopic optic disc photographs (61 subjects) were analyzed. Disc area, rim area, cup area, cup/disc area ratio, vertical cup/disc ratio, rim volume and cup volume were automatically computed by the algorithm. Latent variable measurement error models were used to assess measurement reproducibility for the four techniques. RESULTS: AP had better reproducibility for disc area and cup volume and worse reproducibility for cup/disc area ratio and vertical cup/disc ratio, when the measurements were compared to the MP, SLO and OCT methods. CONCLUSION: AP provides a useful technique for an objective quantitative assessment of 3D ONH structures. PMID:20588996

Composite flywheels with rim and hub

NASA Astrophysics Data System (ADS)

Ikegami, K.; Igarashi, J.-I.; Shiratori, E.

The possibility of obtaining a flywheel of high energy density by increasing both rotating speed and moment of inertia of the disc is investigated. As the starting point of the search process for such a flywheel, a glass cloth-laminated disc with a hole at the center is considered. The rotating speed of the disc is improved by reinforcing the central hole of the disc with the same material as that of the disc. The large moment of inertia is obtained by attaching a rim around the disc. The rim is moulded by winding carbon fiber around it. This rim also has the usual 'hoop' effect which prevents a reduction of the rotating speed of the disc because of the additional moment of inertia of the rim. The shape of the disc having a high energy density is numerically sought by varying the dimensions of the hub and the rim of the disc, and an optimal shape is proposed.

[The Autocad system for planimetric study of the optic disc in glaucoma: technique and reproducibility study].

PubMed

Sánchez Pérez, A; Honrubia López, F M; Larrosa Poves, J M; Polo Llorens, V; Melcon Sánchez-Frieras, B

2001-09-01

To develop a lens planimetry technique for the optic disc using AutoCAD. To determine variability magnitude of the optic disc morphological measurements. We employed AutoCAD R.14.0 Autodesk: image acquisition, contour delimitation by multiple lines fitting or ellipse adjustment, image sectorialization and measurements quantification (optic disc and excavation, vertical diameters, optic disc area, excavation area, neuroretinal sector area and Beta atrophy area). Intraimage or operator and interimage o total reproducibility was studied by coefficient of variability (CV) (n=10) in normal and myopic optic discs. This technique allows to obtain optic disc measurement in 5 to 10 minutes time. Total or interimage variability of measurements introduced by one observer presents CV range from 1.18-4.42. Operator or intraimage measurement presents CV range from 0.30-4.21. Optic disc contour delimitation by ellipse adjustment achieved better reproducibility results than multiple lines adjustment in all measurements. Computer assisted AutoCAD planimetry is an interactive method to analyse the optic disc, feasible to incorporate to clinical practice. Reproducibility results are comparable to other analyzers in quantification optic disc morphology. Ellipse adjustment improves results in optic disc contours delimitation.

Protoplanetary disc `isochrones' and the evolution of discs in the M˙-Md plane

NASA Astrophysics Data System (ADS)

Lodato, Giuseppe; Scardoni, Chiara E.; Manara, Carlo F.; Testi, Leonardo

2017-12-01

In this paper, we compare simple viscous diffusion models for the disc evolution with the results of recent surveys of the properties of young protoplanetary discs. We introduce the useful concept of 'disc isochrones' in the accretion rate-disc mass plane and explore a set of Monte Carlo realization of disc initial conditions. We find that such simple viscous models can provide a remarkable agreement with the available data in the Lupus star forming region, with the key requirement that the average viscous evolutionary time-scale of the discs is comparable to the cluster age. Our models produce naturally a correlation between mass accretion rate and disc mass that is shallower than linear, contrary to previous results and in agreement with observations. We also predict that a linear correlation, with a tighter scatter, should be found for more evolved disc populations. Finally, we find that such viscous models can reproduce the observations in the Lupus region only in the assumption that the efficiency of angular momentum transport is a growing function of radius, thus putting interesting constraints on the nature of the microscopic processes that lead to disc accretion.

BP Piscium: its flaring disc imaged with SPHERE/ZIMPOL★

NASA Astrophysics Data System (ADS)

de Boer, J.; Girard, J. H.; Canovas, H.; Min, M.; Sitko, M.; Ginski, C.; Jeffers, S. V.; Mawet, D.; Milli, J.; Rodenhuis, M.; Snik, F.; Keller, C. U.

2017-03-01

Whether BP Piscium (BP Psc) is either a pre-main sequence T Tauri star at d ≈ 80 pc, or a post-main sequence G giant at d ≈ 300 pc is still not clear. As a first-ascent giant, it is the first to be observed with a molecular and dust disc. Alternatively, BP Psc would be among the nearest T Tauri stars with a protoplanetary disc (PPD). We investigate whether the disc geometry resembles typical PPDs, by comparing polarimetric images with radiative transfer models. Our Very Large Telescope/Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE)/Zurich IMaging Polarimeter (ZIMPOL) observations allow us to perform polarimetric differential imaging, reference star differential imaging, and Richardson-Lucy deconvolution. We present the first visible light polarization and intensity images of the disc of BP Psc. Our deconvolution confirms the disc shape as detected before, mainly showing the southern side of the disc. In polarized intensity the disc is imaged at larger detail and also shows the northern side, giving it the typical shape of high-inclination flared discs. We explain the observed disc features by retrieving the large-scale geometry with MCMAX radiative transfer modelling, which yields a strongly flared model, atypical for discs of T Tauri stars.

The activL® Artificial Disc: a next-generation motion-preserving implant for chronic lumbar discogenic pain

PubMed Central

Yue, James J; Garcia, Rolando; Miller, Larry E

2016-01-01

Degeneration of the lumbar intervertebral discs is a leading cause of chronic low back pain in adults. Treatment options for patients with chronic lumbar discogenic pain unresponsive to conservative management include total disc replacement (TDR) or lumbar fusion. Until recently, only two lumbar TDRs had been approved by the US Food and Drug Administration − the Charité Artificial Disc in 2004 and the ProDisc-L Total Disc Replacement in 2006. In June 2015, a next-generation lumbar TDR received Food and Drug Administration approval − the activL® Artificial Disc (Aesculap Implant Systems). Compared to previous-generation lumbar TDRs, the activL® Artificial Disc incorporates specific design enhancements that result in a more precise anatomical match and allow a range of motion that better mimics the healthy spine. The results of mechanical and clinical studies demonstrate that the activL® Artificial Disc results in improved mechanical and clinical outcomes versus earlier-generation artificial discs and compares favorably to lumbar fusion. The purpose of this report is to describe the activL® Artificial Disc including implant characteristics, intended use, surgical technique, postoperative care, mechanical testing, and clinical experience to date. PMID:27274317

On the illumination of neutron star accretion discs

NASA Astrophysics Data System (ADS)

Wilkins, D. R.

2018-03-01

The illumination of the accretion disc in a neutron star X-ray binary by X-rays emitted from (or close to) the neutron star surface is explored through general relativistic ray tracing simulations. The applicability of the canonical suite of relativistically broadened emission line models (developed for black holes) to discs around neutron stars is evaluated. These models were found to describe well emission lines from neutron star accretion discs unless the neutron star radius is larger than the innermost stable orbit of the accretion disc at 6 rg or the disc is viewed at high inclination, above 60° where shadowing of the back side of the disc becomes important. Theoretical emissivity profiles were computed for accretion discs illuminated by hotspots on the neutron star surfaces, bands of emission and emission by the entirety of the hot, spherical star surface and in all cases, the emissivity profile of the accretion disc was found to be well represented by a single power law falling off slightly steeper than r-3. Steepening of the emissivity index was found where the emission is close to the disc plane and the disc can appear truncated when illuminated by a hotspot at high latitude. The emissivity profile of the accretion disc in Serpens X-1 was measured and found to be consistent with a single unbroken power law with index q=3.5_{-0.4}^{+0.3}, suggestive of illumination by the boundary layer between the disc and neutron star surface.

In vivo biofunctional evaluation of hydrogels for disc regeneration.

PubMed

Reitmaier, Sandra; Kreja, Ludwika; Gruchenberg, Katharina; Kanter, Britta; Silva-Correia, Joana; Oliveira, Joaquim Miguel; Reis, Rui Luís; Perugini, Valeria; Santin, Matteo; Ignatius, Anita; Wilke, Hans-Joachim

2014-01-01

Regenerative strategies aim to restore the original biofunctionality of the intervertebral disc. Different biomaterials are available, which might support disc regeneration. In the present study, the prospects of success of two hydrogels functionalized with anti-angiogenic peptides and seeded with bone marrow derived mononuclear cells (BMC), respectively, were investigated in an ovine nucleotomy model. In a one-step procedure iliac crest aspirates were harvested and, subsequently, separated BMC were seeded on hydrogels and implanted into the ovine disc. For the cell-seeded approach a hyaluronic acid-based hydrogel was used. The anti-angiogenic potential of newly developed VEGF-blockers was investigated on ionically crosslinked metacrylated gellan gum hydrogels. Untreated discs served as nucleotomy controls. 24 adult merino sheep were used. After 6 weeks histological, after 12 weeks histological and biomechanical analyses were conducted. Biomechanical tests revealed no differences between any of the implanted and nucleotomized discs. All implanted discs significantly degenerated compared to intact discs. In contrast, there was no marked difference between implanted and nucleotomized discs. In tendency, albeit not significant, degeneration score and disc height index deteriorated for all but not for the cell-seeded hydrogels from 6 to 12 weeks. Cell-seeded hydrogels slightly decelerated degeneration. None of the hydrogel configurations was able to regenerate biofunctionality of the intervertebral disc. This might presumably be caused by hydrogel extrusion. Great importance should be given to the development of annulus sealants, which effectively exploit the potential of (cell-seeded) hydrogels for biological disc regeneration and restoration of intervertebral disc functioning.

New Brown Dwarf Discs in Upper Scorpius Observed with WISE

NASA Technical Reports Server (NTRS)

Dawson, P.; Scholz, A.; Ray, T. P.; Natta, A.; Marsh, K. A.; Padgett, D.; Ressler, M. E.

2013-01-01

We present a census of the disc population for UKIDSS selected brown dwarfs in the 5-10 Myr old Upper Scorpius OB association. For 116 objects originally identified in UKIDSS, the majority of them not studied in previous publications, we obtain photometry from the Wide-Field Infrared Survey Explorer data base. The resulting colour magnitude and colour colour plots clearly show two separate populations of objects, interpreted as brown dwarfs with discs (class II) and without discs (class III). We identify 27 class II brown dwarfs, 14 of them not previously known. This disc fraction (27 out of 116, or 23%) among brown dwarfs was found to be similar to results for K/M stars in Upper Scorpius, suggesting that the lifetimes of discs are independent of the mass of the central object for low-mass stars and brown dwarfs. 5 out of 27 discs (19 per cent) lack excess at 3.4 and 4.6 microns and are potential transition discs (i.e. are in transition from class II to class III). The transition disc fraction is comparable to low-mass stars.We estimate that the time-scale for a typical transition from class II to class III is less than 0.4 Myr for brown dwarfs. These results suggest that the evolution of brown dwarf discs mirrors the behaviour of discs around low-mass stars, with disc lifetimes of the order of 5 10 Myr and a disc clearing time-scale significantly shorter than 1 Myr.

Posterior epidural disc fragment masquerading as spinal tumor: Review of the literature.

PubMed

Park, Taejune; Lee, Ho Jun; Kim, Jae Seong; Nam, Kiyeun

2018-03-09

Posterior epidural lumbar disc fragment is infrequent because of anatomical barriers, and it is difficult to diagnose posterior epidural lumbar disc fragment because of its rare incidence and the ambiguity of radiologic evaluations. And it is difficult to differentiate it from other diseases such as spinal tumors. Differential diagnosis of posterior epidural lumbar disc fragment is clinically important because its diagnosis can affect treatment and prognosis. To investigate the incidence, anatomical concern, etiology, symptom, diagnostic tool, management and prognosis of posterior epidural lumbar disc fragment, we reviewed articles including case report. We performed a search of all clinical studies of posterior epidural lumbar disc fragment published to date. The following keywords were searched: Posterior epidural lumbar disc fragment, disc migration, posterior epidural disc, extradural migration, dorsal epidural migration, sequestrated disc, and disc fragment. We identified 40 patients of posterior epidural lumbar disc fragment from 28 studies. The most common presentation of posterior epidural lumbar disc fragment was sudden onset radiculopathy (70.0%), followed by cauda equina syndrome (27.5%). The most frequently used diagnostic modality was magnetic resonance imaging (MRI), conducted in 36 cases (90.0%), and followed by computed tomography in 14 cases (35.0%). After the imaging studies, the preoperative diagnoses were 45.0% masses, 20.0% lesions, and 12.5% tumors. Characteristic MRI findings in posterior epidural lumbar disc fragment are helpful for diagnosis; it typically displays low signals on T1-weighted images and high signals on T2-weighted images with respect to the parent disc. In addition, most of the disc fragments show peripheral rim enhancement on MRI with gadolinium administration. Electrodiagnostic testing is useful for verifying nerve damage. Surgical treatment was performed in all cases, and neurologic complications were observed in 12.5%. As posterior epidural lumbar disc fragment could be masqueraded as spinal tumor, if rim enhancement is observed in MRI scans with sudden symptoms of radiculopathy or cauda equina syndrome, it should be taken into consideration. Early diagnosis can lead to early surgery, which can reduce complications.

A fully relativistic twisted disc around a slowly rotating Kerr black hole: derivation of dynamical equations and the shape of stationary configurations

NASA Astrophysics Data System (ADS)

Zhuravlev, V. V.; Ivanov, P. B.

2011-08-01

In this paper we derive equations describing the dynamics and stationary configurations of a twisted fully relativistic thin accretion disc around a slowly rotating black hole. We assume that the inclination angle of the disc is small and that the standard relativistic generalization of the α model of accretion discs is valid when the disc is flat. We find that similar to the case of non-relativistic twisted discs the disc dynamics and stationary shapes can be determined by a pair of equations formulated for two complex variables describing the orientation of the disc rings and velocity perturbations induced by the twist. We analyse analytically and numerically the shapes of stationary twisted configurations of accretion discs having non-zero inclinations with respect to the black hole equatorial plane at large distances r from the black hole. It is shown that the stationary configurations depend on two parameters - the viscosity parameter α and the parameter ?, where δ* is the opening angle (δ*˜h/r, where h is the disc half-thickness and r is large) of a flat disc and a is the black hole rotational parameter. When a > 0 and ? the shapes depend drastically on the value of α. When α is small the disc inclination angle oscillates with radius with amplitude and radial frequency of the oscillations dramatically increasing towards the last stable orbit, Rms. When α has a moderately small value the oscillations do not take place but the disc does not align with the equatorial plane at small radii. The disc inclination angle either is increasing towards Rms or exhibits a non-monotonic dependence on the radial coordinate. Finally, when α is sufficiently large the disc aligns with the equatorial plane at small radii. When a < 0 the disc aligns with the equatorial plane for all values of α. The results reported here may have implications for determining the structure and variability of accretion discs close to Rms as well as for modelling of emission spectra coming from different sources, which are supposed to contain black holes.

[Microcomputer control of a LED stimulus display device].

PubMed

Ohmoto, S; Kikuchi, T; Kumada, T

1987-02-01

A visual stimulus display system controlled by a microcomputer was constructed at low cost. The system consists of a LED stimulus display device, a microcomputer, two interface boards, a pointing device (a "mouse") and two kinds of software. The first software package is written in BASIC. Its functions are: to construct stimulus patterns using the mouse, to construct letter patterns (alphabet, digit, symbols and Japanese letters--kanji, hiragana, katakana), to modify the patterns, to store the patterns on a floppy disc, to translate the patterns into integer data which are used to display the patterns in the second software. The second software package, written in BASIC and machine language, controls display of a sequence of stimulus patterns in predetermined time schedules in visual experiments.

Quantitative analysis of defects in silicon. Silicon sheet growth development for the large are silicon sheet task of the low-cost solar array project

NASA Technical Reports Server (NTRS)

Natesh, R.; Smith, J. M.; Bruce, T.; Oidwai, H. A.

1980-01-01

One hundred and seventy four silicon sheet samples were analyzed for twin boundary density, dislocation pit density, and grain boundary length. Procedures were developed for the quantitative analysis of the twin boundary and dislocation pit densities using a QTM-720 Quantitative Image Analyzing system. The QTM-720 system was upgraded with the addition of a PDP 11/03 mini-computer with dual floppy disc drive, a digital equipment writer high speed printer, and a field-image feature interface module. Three versions of a computer program that controls the data acquisition and analysis on the QTM-720 were written. Procedures for the chemical polishing and etching were also developed.

Contrast changes in fluoroscopic imaging systems and statistical variations of these changes

NASA Technical Reports Server (NTRS)

Bailey, N. A.

1973-01-01

Experimental studies have indicated that: (1) The response of digitized fluoroscopic imaging systems is linear systems is linear with contrast over a rather wide range of absorber and cavity thicknesses. (2) Contrast changes associated with the addition of aluminum, iodine containing contrast agents and air of thicknesses 1mm or less can be detected with a 95% confidence level. (3) The standard deviation associated with such determination using clinically available X-ray generators and video disc recording is less than 1 percent. A large flat screen X-ray image intensifier has been constructed and some preliminary results obtained. Sensitivity achieved makes dose reduction a factor often greater than previously reported for a system using a conventional X-ray image intensifier.

Vortex stretching in self-gravitating protoplanetary discs

NASA Astrophysics Data System (ADS)

Regály, Zs.; Vorobyov, E.

2017-10-01

Horseshoe-shaped brightness asymmetries of several transitional discs are thought to be caused by large-scale vortices. Anticyclonic vortices efficiently collect dust particles, therefore they can play a major role in planet formation. Former studies suggest that the disc self-gravity weakens vortices formed at the edge of the gap opened by a massive planet in discs whose masses are in the range of 0.01 ≤ Mdisc/M* ≤ 0.1. Here, we present an investigation on the long-term evolution of the large-scale vortices formed at the viscosity transition of the discs' dead zone outer edge by means of two-dimensional hydrodynamic simulations taking disc self-gravity into account. We perform a numerical study of low-mass, 0.001 ≤ Mdisc/M* ≤ 0.01, discs, for which cases disc self-gravity was previously neglected. The large-scale vortices are found to be stretched due to disc self-gravity even for low-mass discs with Mdisc/M* ≳ 0.005, where initially the Toomre Q-parameter was ≲ 50 at the vortex distance. As a result of stretching, the vortex aspect ratio increases and a weaker azimuthal density contrast develops. The strength of the vortex stretching is proportional to the disc mass. The vortex stretching can be explained by a combined action of a non-vanishing gravitational torque caused by the vortex and the Keplerian shear of the disc. Self-gravitating vortices are subject to significantly faster decay than non-self-gravitating ones. We found that vortices developed at sharp viscosity transitions of self-gravitating discs can be described by a Goodman - Narayan - Goldreich (GNG) model as long as the disc viscosity is low, I.e. αdz ≤ 10-5.

Intradiscal pressure study of percutaneous disc decompression with nucleoplasty in human cadavers.

PubMed

Chen, Yung C; Lee, Sang-heon; Chen, Darwin

2003-04-01

Intradiscal pressure was measured after percutaneous disc decompression by nucleoplasty in human cadavers with different degrees of disc degeneration. To assess intradiscal pressure change after disc decompression, and to analyze the influence of degeneration on the intradiscal pressure change. Partial removal of the nucleus has been shown to decompress herniated discs, relieving pressure on nerve roots and, in some cases, offering relief from disc pain. Nucleoplasty, a new minimally invasive procedure using patented Coblation technology, combines coagulation and ablation for partial removal of the nucleus. Coblated channels remove the tissue volume and may decrease the disc pressure. Three fresh human cadaver spinal specimens (T8-L5; age, 54-84 years; mean age, 70.7 years) were used in this investigation. The intradiscal pressure was measured at three points: before treatment, after each channel was created, and after treatment using a 25-guage 6-inch needle connected to a Merit Medical Systems Intellisystem Inflation Monitor. The needles were calibrated initially to approximately 30 pounds per square inch. For the control, the change in disc pressure was recorded by the same procedure without using Coblation energy. To evaluate the effectiveness of nucleoplasty, disc pressure changes were compared between treatment with and without Coblation energy. Intradiscal pressure was markedly reduced in the younger, healthy disc cadaver. In the older, degenerative disc cadavers, the change in intradiscal pressure after nucleoplasty was very small. There was an inverse correlation between the degree of disc degeneration and the change in intradiscal pressure. Pressure reduction through nucleoplasty is highly dependent on the degree of spine degeneration. Nucleoplasty markedly reduced intradiscal pressure in nondegenerative discs, but had a negligible effect on highly degenerative discs.

Biometry and spectral domain optical coherence tomography parameters in children with large cupping.

PubMed

Jung, Jong Jin; Baek, Seung-Hee; Kim, Ungsoo Samuel

2013-09-01

The purpose of this study is to investigate optic nerve head using spectral domain optical coherence tomography (SD-OCT) in children with large cupping. 111 eyes (4-10 years) were divided into three groups according to the cup to disc ratio: group 1, ≤0.3; group 2, 0.4-0.6; and group 3, ≥0.7. The rim area, disc area, average cup to disc ratio, vertical cup to disc ratio, and cup volume were investigated using SD-OCT (Cirrus HD-OCT, Carl Zeiss, Jena, Germany), and the axial length and anterior chamber depth (ACD) were measured by IOL master (IOL master 500, Carl Zeiss, Jena, Germany). Next, we compared ocular biometry and SD-OCT between the three groups. The mean age of group 1 was 6.48 ± 1.42 years, 7.00 ± 1.75 years in group 2, and 6.63 ± 1.82 years in group 3 (p = 0.370). A significant difference was seen in the spherical equivalent between the groups (p = 0.001). Group 2 had the most myopic refractive errors. As the cup to disc ratio increases, disc area, average cup to disc ratio, vertical cup to disc ratio, and cup volume increase significantly. When the results of ocular biometry and SD-OCT are adjusted for axial length, only disc area showed a significant correlation with cup to disc ratio (ACD: p = 0.473, rim area: p = 0.639, disc area: p = 0.005, and cup volume: p = 0.325). Axial length is the key factor determining disc size, which in turn is important for determining cup to disc ratio. Normal children with large cupping should be examined for axial length, myopic refractive errors, and disc size.

Engineered disc-like angle-ply structures for intervertebral disc replacement.

PubMed

Nerurkar, Nandan L; Sen, Sounok; Huang, Alice H; Elliott, Dawn M; Mauck, Robert L

2010-04-15

To develop a construction algorithm in which electrospun nanofibrous scaffolds are coupled with a biocompatible hydrogel to engineer a mesenchymal stem cell (MSC)-based disc replacement. To engineer a disc-like angle-ply structure (DAPS) that replicates the multiscale architecture of the intervertebral disc. Successful engineering of a replacement for the intervertebral disc requires replication of its mechanical function and anatomic form. Despite many attempts to engineer a replacement for ailing and degenerated discs, no prior study has replicated the multiscale hierarchical architecture of the native disc, and very few have assessed the mechanical function of formed neo-tissues. A new algorithm for the construction of a disc analogue was developed, using agarose to form a central nucleus pulposus (NP) and oriented electrospun nanofibrous scaffolds to form the anulus fibrosus region (AF). Bovine MSCs were seeded into both regions and biochemical, histologic, and mechanical maturation were evaluated with in vitro culture. We show that mechanical testing in compression and torsion, loading methods commonly used to assess disc mechanics, reveal equilibrium and time-dependent behaviors that are qualitatively similar to native tissue, although lesser in magnitude. Further, we demonstrate that cells seeded into both AF and NP regions adopt distinct morphologies that mirror those seen in native tissue, and that, in the AF region, this ordered community of cells deposit matrix that is organized in an angle-ply configuration. Finally, constructs demonstrate functional development with long-term in vitro culture. These findings provide a new approach for disc tissue engineering that replicates multi-scale form and function of the intervertebral disc, providing a foundation from which to build a multi-scale, biologic, anatomically and hierarchically relevant composite disc analogue for eventual disc replacement.

Mechanoreceptors in Diseased Cervical Intervertebral Disc and Vertigo.

PubMed

Yang, Liang; Yang, Cheng; Pang, Xiaodong; Li, Duanming; Yang, Hong; Zhang, Xinwu; Yang, Yi; Peng, Baogan

2017-04-15

We collected the samples of cervical intervertebral discs from patients with vertigo to examine the distribution and types of mechanoreceptors in diseased cervical disc. The aim of this study was to determine whether mechanoreceptors are distributed more abundantly in cervical discs from patients with cervical spondylosis, and whether they are related to vertigo. Previous limited studies have found that normal cervical intervertebral discs are supplied with mechanoreceptors that have been considered responsible for proprioceptive functions. Several clinical studies have indicated that the patients with cervical spondylosis manifested significantly impaired postural control and subjective balance disturbance. We collected 77 samples of cervical discs from 62 cervical spondylosis patients without vertigo, 61 samples from 54 patients with vertigo, and 40 control samples from 8 cadaveric donors to investigate distribution of mechanoreceptors containing neurofilament (NF200) and S-100 protein immunoreactive nerve endings. The immunohistochemical investigation revealed that the most frequently encountered mechanoreceptors were the Ruffini corpuscles in all groups of cervical disc samples. They were obviously increased in the number and deeply ingrown into inner annulus fibrosus and even into nucleus pulposus in the diseased cervical discs from patients with vertigo in comparison with the discs from patients without vertigo and control discs. Only three Golgi endings were seen in the three samples from patients with vertigo. No Pacinian corpuscles were found in any samples of cervical discs. The diseased cervical discs from patients with vertigo had more abundant distribution of Ruffini corpuscles than other discs. A positive association between the increased number and ingrowth of Ruffini corpuscles in the diseased cervical disc and the incidence of vertigo in the patients with cervical spondylosis was found, which may indicate a key role of Ruffini corpuscles in the pathogenesis of vertigo of cervical origin. 1.

A Versatile Time-Lapse Camera System Developed by the Hawaiian Volcano Observatory for Use at Kilauea Volcano, Hawaii

USGS Publications Warehouse

Orr, Tim R.; Hoblitt, Richard P.

2008-01-01

Volcanoes can be difficult to study up close. Because it may be days, weeks, or even years between important events, direct observation is often impractical. In addition, volcanoes are often inaccessible due to their remote location and (or) harsh environmental conditions. An eruption adds another level of complexity to what already may be a difficult and dangerous situation. For these reasons, scientists at the U.S. Geological Survey (USGS) Hawaiian Volcano Observatory (HVO) have, for years, built camera systems to act as surrogate eyes. With the recent advances in digital-camera technology, these eyes are rapidly improving. One type of photographic monitoring involves the use of near-real-time network-enabled cameras installed at permanent sites (Hoblitt and others, in press). Time-lapse camera-systems, on the other hand, provide an inexpensive, easily transportable monitoring option that offers more versatility in site location. While time-lapse systems lack near-real-time capability, they provide higher image resolution and can be rapidly deployed in areas where the use of sophisticated telemetry required by the networked cameras systems is not practical. This report describes the latest generation (as of 2008) time-lapse camera system used by HVO for photograph acquisition in remote and hazardous sites on Kilauea Volcano.

OSCAR: A Compact, Powerful and Versatile On Board Computer Based on LEON3 Core

NASA Astrophysics Data System (ADS)

Poupat, Jean-Luc; Lefevre, Aurelien; Koebel, Franck

2011-08-01

Satellites are controlled via a platform On Board Computer (OBC) that manages different parameters (attitude, orbit, modes, temperatures ...) with respect to its payload mission (telecommunication, earth observation, scientific mission). The platform OBC is connected to the satellite and the ground control via digital links, and executes on board software.The main functions of a platform OBC are to provide the satellite flight segment with the following features: o Processing resources for the flight mission software o TM/TC services and interfaces with the RF communication chaino General communication services with the Avionicsand payload equipments through an on-board communication bus based on the MIL-1553B standard or CANo Time synchronization and distributiono Failure tolerant architecture based on the use of redounded reconfiguration units and redundancyimplementationFrom a hardware point of view, it groups a lot of digital functions usually dispatched on numerous chips (processor, co-processor, digital links IP ...) together. In order to reach an ultimate level of integration, Astrium has designed an ASIC gathering on a single chip all the required digital functions: the SCOC3 ASIC.Astrium has developed an OBC based on this SCOC3 ASIC: the OSCAR (Optimized Spacecraft Computer Architecture with Reconfiguration). It is now available off-the-shelf as the new OBC product family of Astrium.This paper presents the major innovations introduced by Astrium for SCOC3 and OSCAR with the objective to save cost and mass through a solution compatible with any class quality project, using a unique software development environment for user.

Star-disc interaction in galactic nuclei: formation of a central stellar disc

NASA Astrophysics Data System (ADS)

Panamarev, Taras; Shukirgaliyev, Bekdaulet; Meiron, Yohai; Berczik, Peter; Just, Andreas; Spurzem, Rainer; Omarov, Chingis; Vilkoviskij, Emmanuil

2018-05-01

We perform high-resolution direct N-body simulations to study the effect of an accretion disc on stellar dynamics in an active galactic nucleus (AGN). We show that the interaction of the nuclear stellar cluster (NSC) with the gaseous accretion disc (AD) leads to formation of a stellar disc in the central part of the NSC. The accretion of stars from the stellar disc on to the super-massive black hole is balanced by the capture of stars from the NSC into the stellar disc, yielding a stationary density profile. We derive the migration time through the AD to be 3 per cent of the half-mass relaxation time of the NSC. The mass and size of the stellar disc are 0.7 per cent of the mass and 5 per cent of the influence radius of the super-massive black hole. An AD lifetime shorter than the migration time would result in a less massive nuclear stellar disc. The detection of such a stellar disc could point to past activity of the hosting galactic nucleus.

Does T2 mapping of the posterior annulus fibrosus indicate the presence of lumbar intervertebral disc herniation? A 3.0 Tesla magnetic resonance study.

PubMed

Messner, Alina; Stelzeneder, David; Trattnig, Stefan; Welsch, Götz H; Schinhan, Martina; Apprich, Sebastian; Brix, Martin; Windhager, Reinhard; Trattnig, Siegfried

2017-03-01

Indicating lumbar disc herniation via magnetic resonance imaging (MRI) T2 mapping in the posterior annulus fibrosus (AF). Sagittal T2 maps of 313 lumbar discs of 64 patients with low back pain were acquired at 3.0 Tesla (3T). The discs were rated according to disc herniation and bulging. Region of interest (ROI) analysis was performed on median, sagittal T2 maps. T2 values of the AF, in the most posterior 10% (PAF-10) and 20% of the disc (PAF-20), were compared. A significant increase in the T2 values of discs with herniations affecting the imaged area, compared to bulging discs and discs with lateral herniation, was shown in the PAF-10, where no association to the NP was apparent. The PAF-20 exhibited a moderate correlation to the nucleus pulposus (NP). High T2 values in the PAF-10 suggest the presence of disc herniation (DH). The results indicate that T2 values in the PAF-20 correspond more to changes in the NP.

Segmentation of optic disc and optic cup in retinal fundus images using shape regression.

PubMed

Sedai, Suman; Roy, Pallab K; Mahapatra, Dwarikanath; Garnavi, Rahil

2016-08-01

Glaucoma is one of the leading cause of blindness. The manual examination of optic cup and disc is a standard procedure used for detecting glaucoma. This paper presents a fully automatic regression based method which accurately segments optic cup and disc in retinal colour fundus image. First, we roughly segment optic disc using circular hough transform. The approximated optic disc is then used to compute the initial optic disc and cup shapes. We propose a robust and efficient cascaded shape regression method which iteratively learns the final shape of the optic cup and disc from a given initial shape. Gradient boosted regression trees are employed to learn each regressor in the cascade. A novel data augmentation approach is proposed to improve the regressors performance by generating synthetic training data. The proposed optic cup and disc segmentation method is applied on an image set of 50 patients and demonstrate high segmentation accuracy for optic cup and disc with dice metric of 0.95 and 0.85 respectively. Comparative study shows that our proposed method outperforms state of the art optic cup and disc segmentation methods.

Vertebral Augmentation can Induce Early Signs of Degeneration in the Adjacent Intervertebral Disc: Evidence from a Rabbit Model.

PubMed

Feng, Zhiyun; Chen, Lunhao; Hu, Xiaojian; Yang, Ge; Wang, Yue; Chen, Zhong

2018-04-11

An experimental study. The aim of this study was to determine the effect of polymethylmethacrylate (PMMA) augmentation on the adjacent disc. Vertebral augmentation with PMMA reportedly may predispose the adjacent vertebra to fracture. The influence of PMMA augmentation on the adjacent disc, however, remains unclear. Using a retroperitoneal approach, PMMA augmentation was performed for 23 rabbits. For each animal, at least one vertebra was augmented with 0.2 to 0.3 mL PMMA. The disc adjacent to the augmented vertebra and a proximal control disc were studied using magnetic resonance (MR) imaging, histological and molecular level evaluation at 1, 3, and 6 months postoperatively. Marrow contact channels in the endplate were quantified in histological slices and number of invalid channels (those without erythrocytes inside) was rated. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) was performed to determine disc cell apoptosis. On MR images, the signal and height of the adjacent disc did not change 6 months after vertebral augmentation. Histological scores of the adjacent disc increased over time, particularly for the nucleus pulposus. The adjacent disc had greater nucleus degeneration score than the control disc at 3 months (5.7 vs. 4.5, P < 0.01) and 6 months (6.9 vs. 4.4, P < 0.001). There were more invalid marrow contact channels in the endplate of augmented vertebra than the control (43.3% vs. 11.1%, P < 0.01). mRNA of ADAMTS-5, MMP-13, HIF-1α, and caspase-3 were significantly upregulated in the adjacent disc at 3 and 6 months (P < 0.05 for all). In addition, there were more TUNEL-positive cells in the adjacent disc than in the control disc (43.4% vs. 24.0%, P < 0.05) at 6 months postoperatively. Vertebral augmentation can induce early degenerative signs in the adjacent disc, which may be due to impaired nutrient supply to the disc. N/A.

First results of the SONS survey: submillimetre detections of debris discs

NASA Astrophysics Data System (ADS)

Panić, O.; Holland, W. S.; Wyatt, M. C.; Kennedy, G. M.; Matthews, B. C.; Lestrade, J. F.; Sibthorpe, B.; Greaves, J. S.; Marshall, J. P.; Phillips, N. M.; Tottle, J.

2013-10-01

New detections of debris discs at submillimetre wavelengths present highly valuable complementary information to prior observations of these sources at shorter wavelengths. Characterization of discs through spectral energy distribution modelling including the submillimetre fluxes is essential for our basic understanding of disc mass and temperature, and presents a starting point for further studies using millimetre interferometric observations. In the framework of the ongoing SCUBA-2 Observations of Nearby Stars, the instrument SCUBA-2 on the James Clerk Maxwell Telescope was used to provide measurements of 450 and 850 μm fluxes towards a large sample of nearby main-sequence stars with debris discs detected previously at shorter wavelengths. We present the first results from the ongoing survey, concerning 850 μm detections and 450 μm upper limits towards 10 stars, the majority of which are detected at submillimetre wavelengths for the first time. One, or possibly two, of these new detections is likely a background source. We fit the spectral energy distributions of the star+disc systems with a blackbody emission approach and derive characteristic disc temperatures. We use these temperatures to convert the observed fluxes to disc masses. We obtain a range of disc masses from 0.001 to 0.1 M⊕, values similar to the prior dust mass measurements towards debris discs. There is no evidence for evolution in dust mass with age on the main sequence, and indeed the upper envelope remains relatively flat at ≈0.5 M⊕ at all ages. The inferred disc masses are lower than those from disc detections around pre-main-sequence stars, which may indicate a depletion of solid mass. This may also be due to a change in disc opacity, though limited sensitivity means that it is not yet known what fraction of pre-main-sequence stars have discs with dust masses similar to debris disc levels. New, high-sensitivity detections are a path towards investigating the trends in dust mass evolution.

Comparison of Ripening Processes in Intact Tomato Fruit and Excised Pericarp Discs 1

PubMed Central

Campbell, Alan D.; Huysamer, Marius; Stotz, Henrik U.; Greve, L. Carl; Labavitch, John M.

1990-01-01

Physiological processes characteristic of ripening in tissues of intact tomato fruit (Lycopersicon esculentum Mill.) were examined in excised pericarp discs. Pericarp discs were prepared from mature-green tomato fruit and stored in 24-well culture plates, in which individual discs could be monitored for color change, ethylene biosynthesis, and respiration, and selected for cell wall analysis. Within the context of these preparation and handling procedures, most whole fruit ripening processes were maintained in pericarp discs. Pericarp discs and matched intact fruit passed through the same skin color stages at similar rates, as expressed in the L*a*b* color space, changing from green (a* < −5) to red (a* > 15) in about 6 days. Individual tissues of the pericarp discs changed color in the same sequence seen in intact fruit (exocarp, endocarp, then vascular parenchyma). Discs from different areas changed in the same spatial sequence seen in intact fruit (bottom, middle, top). Pericarp discs exhibited climacteric increases in ethylene biosynthesis and CO2 production comparable with those seen in intact fruit, but these were more tightly linked to rate of color change, reaching a peak around a* = 5. Tomato pericarp discs decreased in firmness as color changed. Cell wall carbohydrate composition changed with color as in intact fruit: the quantity of water-soluble pectin eluted from the starch-free alcohol insoluble substances steadily increased and more tightly bound, water-insoluble, pectin decreased in inverse relationship. The cell wall content of the neutral sugars arabinose, rhamnose, and galactose steadily decreased as color changed. The extractable activity of specific cell wall hydrolases changed as in intact fruit: polygalacturonase activity, not detectable in green discs (a* = −5), appeared as discs turned yellow-red (a* = 5), and increased another eight-fold as discs became full red (a* value +20). Carboxymethyl-cellulase activity, low in extracts from green discs, increased about six-fold as discs changed from yellow (a* = 0) to red. PMID:16667893

Patterns of lumbar disc degeneration are different in degenerative disc disease and disc prolapse magnetic resonance imaging analysis of 224 patients.

PubMed

Kanna, Rishi M; Shetty, Ajoy Prasad; Rajasekaran, S

2014-02-01

Existing research on lumbar disc degeneration has remained inconclusive regarding its etiology, pathogenesis, symptomatology, prevention, and management. Degenerative disc disease (DDD) and disc prolapse (DP) are common diseases affecting the lumbar discs. Although they manifest clinically differently, existing studies on disc degeneration have included patients with both these features, leading to wide variations in observations. The possible relationship or disaffect between DDD and DP is not fully evaluated. To analyze the patterns of lumbar disc degeneration in patients with chronic back pain and DDD and those with acute DP. Prospective, magnetic resonance imaging-based radiological study. Two groups of patients (aged 20-50 years) were prospectively studied. Group 1 included patients requiring a single level microdiscectomy for acute DP. Group 2 included patients with chronic low back pain and DDD. Discs were assessed by magnetic resonance imaging through Pfirmann grading, Schmorl nodes, Modic changes, and the total end-plate damage score for all the five lumbar discs. Group 1 (DP) had 91 patients and group 2 (DDD) had 133 patients. DP and DDD patients differed significantly in the number, extent, and severity of degeneration. DDD patients had a significantly higher number of degenerated discs than DP patients (p<.000). The incidence of multilevel and pan-lumbar degeneration was also significantly higher in DDD group. The pattern of degeneration also differed in both the groups. DDD patients had predominant upper lumbar involvement, whereas DP patients had mainly lower lumbar degeneration. Modic changes were more common in DP patients, especially at the prolapsed level. Modic changes were present in 37% of prolapsed levels compared with 9.9% of normal discs (p<.00). The total end-plate damage score had a positive correlation with disc degeneration in both the groups. Further the mean total end-plate damage score at prolapsed level was also significantly higher. The results suggest that patients with disc prolapse, and those with back pain with DDD are clinically and radiologically different groups of patients with varying patterns, severity, and extent of disc degeneration. This is the first study in literature to compare and identify significant differences in these two commonly encountered patient groups. In patients with single-level DP, the majority of the other discs are nondegenerate, the lower lumbar spine is predominantly involved and the end-plate damage is higher. Patients with back pain and DDD have larger number of degenerate discs, early multilevel degeneration, and predominant upper lumbar degeneration. The knowledge that these two groups of patients are different clinically and radiologically is critical for our improved understanding of the disease and for future studies on disc degeneration and disc prolapse. Copyright © 2014 Elsevier Inc. All rights reserved.

Signatures of broken protoplanetary discs in scattered light and in sub-millimetre observations

NASA Astrophysics Data System (ADS)

Facchini, Stefano; Juhász, Attila; Lodato, Giuseppe

2018-02-01

Spatially resolved observations of protoplanetary discs are revealing that their inner regions can be warped or broken from the outer disc. A few mechanisms are known to lead to such 3D structures; among them, the interaction with a stellar companion. We perform a 3D SPH simulation of a circumbinary disc misaligned by 60° with respect to the binary orbital plane. The inner disc breaks from the outer regions, precessing as a rigid body and leading to a complex evolution. As the inner disc precesses, the misalignment angle between the inner and outer discs varies by more than 100°. Different snapshots of the evolution are post-processed with a radiative transfer code, in order to produce observational diagnostics of the process. Even though the simulation was produced for the specific case of a circumbinary disc, most of the observational predictions hold for any disc hosting a precessing inner rim. Synthetic scattered light observations show strong azimuthal asymmetries, where the pattern depends strongly on the misalignment angle between the inner and outer discs. The asymmetric illumination of the outer disc leads to azimuthal variations of the temperature structure, in particular in the upper layers, where the cooling time is short. These variations are reflected in asymmetric surface brightness maps of optically thick lines, as CO J = 3-2. The kinematical information obtained from the gas lines is unique in determining the disc structure. The combination of scattered light images and (sub-)mm lines can distinguish between radial inflow and misaligned inner disc scenarios.

Radiologic study of disc behavior following compression fracture of the thoracolumbar hinge managed by kyphoplasty: A 52-case series.

PubMed

Teyssédou, S; Saget, M; Gayet, L E; Pries, P; Brèque, C; Vendeuvre, T

2016-02-01

Kyphoplasty has proved effective for durable correction of traumatic vertebral deformity following Magerl A fracture, but subsequent behavior of the adjacent discs is unclear. The objective of the present study was to analyze evolution according to severity of initial kyphosis and quality of fracture reduction. A single-center prospective study included cases of single compression fracture of the thoracolumbar hinge managed by Kyphon Balloon Kyphoplasty with polymethylmethacrylate bone cement. Radiology focused on traumatic vertebral kyphosis (VK), disc angulation (DA) and disc height index (DHI) in the adjacent discs. Linear regression assessed the correlation between superior disc height index (SupDHI) and postoperative VK on the one hand and correction gain on the other, using the Student t test for matched pairs and Pearson correlation coefficient. Fifty-two young patients were included, with mean follow-up of 18.6 months. VK fell from 13.9° preoperatively to 8.2° at last follow-up. DHI found significant superior disc subsidence (P=0.0001) and non-significant inferior disc subsidence (P=0.116). DA showed significantly reduced superior disc lordosis (P=4*10(-5)). SupDHI correlated with VK correction (r=0.32). Preoperative VK did not correlate with radiologic degeneration of the adjacent discs. Correction of traumatic vertebral deformity avoids subsidence and loss of mechanical function in the superior adjacent disc. The underlying disc compensates for residual deformity. Balloon kyphoplasty is useful in compression fracture, providing significant reduction of traumatic vertebral deformity while conserving free and healthy adjacent discs. IV. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Rat disc torsional mechanics: effect of lumbar and caudal levels and axial compression load.

PubMed

Espinoza Orías, Alejandro A; Malhotra, Neil R; Elliott, Dawn M

2009-03-01

Rat models with altered loading are used to study disc degeneration and mechano-transduction. Given the prominent role of mechanics in disc function and degeneration, it is critical to measure mechanical behavior to evaluate changes after model interventions. Axial compression mechanics of the rat disc are representative of the human disc when normalized by geometry, and differences between the lumbar and caudal disc have been quantified in axial compression. No study has quantified rat disc torsional mechanics. Compare the torsional mechanical behavior of rat lumbar and caudal discs, determine the contribution of combined axial load on torsional mechanics, and compare the torsional properties of rat discs to human lumbar discs. Cadaveric biomechanical study. Cyclic torsion without compressive load followed by cyclic torsion with a fixed compressive load was applied to rat lumbar and caudal disc levels. The apparent torsional modulus was higher in the lumbar region than in the caudal region: 0.081+/-0.026 (MPa/degrees, mean+/-SD) for lumbar axially loaded; 0.066+/-0.028 for caudal axially loaded; 0.091+/-0.033 for lumbar in pure torsion; and 0.056+/-0.035 for caudal in pure torsion. These values were similar to human disc properties reported in the literature ranging from 0.024 to 0.21 MPa/degrees. Use of the caudal disc as a model may be appropriate if the mechanical focus is within the linear region of the loading regime. These results provide support for use of this animal model in basic science studies with respect to torsional mechanics.

Eccentricity evolution during planet-disc interaction

NASA Astrophysics Data System (ADS)

Ragusa, Enrico; Rosotti, Giovanni; Teyssandier, Jean; Booth, Richard; Clarke, Cathie J.; Lodato, Giuseppe

2018-03-01

During the process of planet formation, the planet-disc interactions might excite (or damp) the orbital eccentricity of the planet. In this paper, we present two long (t ˜ 3 × 105 orbits) numerical simulations: (a) one (with a relatively light disc, Md/Mp = 0.2), where the eccentricity initially stalls before growing at later times and (b) one (with a more massive disc, Md/Mp = 0.65) with fast growth and a late decrease of the eccentricity. We recover the well-known result that a more massive disc promotes a faster initial growth of the planet eccentricity. However, at late times the planet eccentricity decreases in the massive disc case, but increases in the light disc case. Both simulations show periodic eccentricity oscillations superimposed on a growing/decreasing trend and a rapid transition between fast and slow pericentre precession. The peculiar and contrasting evolution of the eccentricity of both planet and disc in the two simulations can be understood by invoking a simple toy model where the disc is treated as a second point-like gravitating body, subject to secular planet-planet interaction and eccentricity pumping/damping provided by the disc. We show how the counterintuitive result that the more massive simulation produces a lower planet eccentricity at late times can be understood in terms of the different ratios of the disc-to-planet angular momentum in the two simulations. In our interpretation, at late times the planet eccentricity can increase more in low-mass discs rather than in high-mass discs, contrary to previous claims in the literature.

Novel Human Intervertebral Disc Strain Template to Quantify Regional Three-Dimensional Strains in a Population and Compare to Internal Strains Predicted by a Finite Element Model

PubMed Central

Showalter, Brent L.; DeLucca, John F.; Peloquin, John M.; Cortes, Daniel H.; Yoder, Jonathon H.; Jacobs, Nathan T.; Wright, Alexander C.; Gee, James C.; Vresilovic, Edward J.; Elliott, Dawn M.

2017-01-01

Tissue strain is an important indicator of mechanical function, but is difficult to noninvasively measure in the intervertebral disc. The objective of this study was to generate a disc strain template, a 3D average of disc strain, of a group of human L4–L5 discs loaded in axial compression. To do so, magnetic resonance images of uncompressed discs were used to create an average disc shape. Next, the strain tensors were calculated pixel-wise by using a previously developed registration algorithm. Individual disc strain tensor components were then transformed to the template space and averaged to create the disc strain template. The strain template reduced individual variability while highlighting group trends. For example, higher axial and circumferential strains were present in the lateral and posterolateral regions of the disc, which may lead to annular tears. This quantification of group-level trends in local 3D strain is a significant step forward in the study of disc biomechanics. These trends were compared to a finite element model that had been previously validated against the disc-level mechanical response. Depending on the strain component, 81–99% of the regions within the finite element model had calculated strains within one standard deviation of the template strain results. The template creation technique provides a new measurement technique useful for a wide range of studies, including more complex loading conditions, the effect of disc pathologies and degeneration, damage mechanisms, and design and evaluation of treatments. PMID:26694516

Lumbar Disc Degenerative Disease: Disc Degeneration Symptoms and Magnetic Resonance Image Findings

PubMed Central

Saleem, Shafaq; Rehmani, Muhammad Asim Khan; Raees, Aisha; Alvi, Arsalan Ahmad; Ashraf, Junaid

2013-01-01

Study Design Cross sectional and observational. Purpose To evaluate the different aspects of lumbar disc degenerative disc disease and relate them with magnetic resonance image (MRI) findings and symptoms. Overview of Literature Lumbar disc degenerative disease has now been proven as the most common cause of low back pain throughout the world. It may present as disc herniation, lumbar spinal stenosis, facet joint arthropathy or any combination. Presenting symptoms of lumbar disc degeneration are lower back pain and sciatica which may be aggravated by standing, walking, bending, straining and coughing. Methods This study was conducted from January 2012 to June 2012. Study was conducted on the diagnosed patients of lumbar disc degeneration. Diagnostic criteria were based upon abnormal findings in MRI. Patients with prior back surgery, spine fractures, sacroiliac arthritis, metabolic bone disease, spinal infection, rheumatoid arthritis, active malignancy, and pregnancy were excluded. Results During the targeted months, 163 patients of lumbar disc degeneration with mean age of 43.92±11.76 years, came into Neurosurgery department. Disc degeneration was most commonly present at the level of L4/L5 105 (64.4%).Commonest types of disc degeneration were disc herniation 109 (66.9%) and lumbar spinal stenosis 37 (22.7%). Spondylolisthesis was commonly present at L5/S1 10 (6.1%) and associated mostly with lumbar spinal stenosis 7 (18.9%). Conclusions Results reported the frequent occurrence of lumbar disc degenerative disease in advance age. Research efforts should endeavor to reduce risk factors and improve the quality of life. PMID:24353850

Forming disc galaxies in major mergers - III. The effect of angular momentum on the radial density profiles of disc galaxies

NASA Astrophysics Data System (ADS)

Peschken, N.; Athanassoula, E.; Rodionov, S. A.

2017-06-01

We study the effect of angular momentum on the surface density profiles of disc galaxies, using high-resolution simulations of major mergers whose remnants have downbending radial density profiles (type II). As described in the previous papers of this series, in this scenario, most of the disc mass is acquired after the collision via accretion from a hot gaseous halo. We find that the inner and outer disc scalelengths, as well as the break radius, correlate with the total angular momentum of the initial merging system, and are larger for high-angular momentum systems. We follow the angular momentum redistribution in our simulated galaxies, and find that like the mass, the disc angular momentum is acquired via accretion, I.e. to the detriment of the gaseous halo. Furthermore, high-angular momentum systems give more angular momentum to their discs, which directly affects their radial density profile. Adding simulations of isolated galaxies to our sample, we find that the correlations are valid also for disc galaxies evolved in isolation. We show that the outer part of the disc at the end of the simulation is populated mainly by inside-out stellar migration, and that in galaxies with higher angular momentum, stars travel radially further out. This, however, does not mean that outer disc stars (in type II discs) were mostly born in the inner disc. Indeed, generally the break radius increases over time, and not taking this into account leads to overestimating the number of stars born in the inner disc.

The role of disc self-gravity in circumbinary planet systems - I. Disc structure and evolution

NASA Astrophysics Data System (ADS)

Mutter, Matthew M.; Pierens, Arnaud; Nelson, Richard P.

2017-03-01

We present the results of two-dimensional hydrodynamic simulations of self-gravitating circumbinary discs around binaries whose parameters match those of the circumbinary planet-hosting systems Kepler-16, Kepler-34 and Kepler-35. Previous work has shown that non-self-gravitating discs in these systems form an eccentric precessing inner cavity due to tidal truncation by the binary, and planets which form at large radii migrate until stalling at this cavity. Whilst this scenario appears to provide a natural explanation for the observed orbital locations of the circumbinary planets, previous simulations have failed to match the observed planet orbital parameters. The aim of this work is to examine the role of self-gravity in modifying circumbinary disc structure as a function of disc mass, prior to considering the evolution of embedded circumbinary planets. In agreement with previous work, we find that for disc masses between one and five times the minimum mass solar nebula (MMSN), disc self-gravity affects modest changes in the structure and evolution of circumbinary discs. Increasing the disc mass to 10 or 20 MMSN leads to two dramatic changes in disc structure. First, the scale of the inner cavity shrinks substantially, bringing its outer edge closer to the binary. Secondly, in addition to the eccentric inner cavity, additional precessing eccentric ring-like features develop in the outer regions of the discs. If planet formation starts early in the disc lifetime, these changes will have a significant impact on the formation and evolution of planets and precursor material.

Radial modes of laterally stiffened piezoelectric disc transducers for ultrasonic collimated beam generation

DOE PAGES

Chillara, Vamshi Krishna; Pantea, Cristian; Sinha, Dipen N.

2017-07-15

Here, we numerically investigate the resonance and vibration characteristics of radial modes of laterally stiffened piezoelectric disc transducers. Lateral stiffening is modeled using a spring and vibration characteristics of the piezo-disc are investigated with increasing lateral stiffness. It is found that the resonant frequency response of the radial modes follows an asymptotic behavior approaching that of a clamped disc with increasing lateral stiffness. The radial mode vibration pattern of the discs is also found to be affected by lateral stiffness. While the vibration pattern of a free disc corresponds to a Bessel function, laterally stiffened discs show edge-effects where theymore » depart from the Bessel-like behavior. In addition, a fully clamped piezo-disc is found to have an extra side-lobe when compared to a free disc. Ultrasonic beam profiles generated from radial modes of laterally stiffened discs are numerically investigated. It is found that the free piezo-disc generates a Bessel beam that has multiple side-lobes. Increasing the lateral stiffness results in a significant reduction of side-lobes in the beam profile. This technique of generating a collimated beam with side-lobe reduction finds significant applications in imaging through concrete, drilling mud, and other highly attenuating materials.« less

Construction Strategy and Progress of Whole Intervertebral Disc Tissue Engineering.

PubMed

Yang, Qiang; Xu, Hai-wei; Hurday, Sookesh; Xu, Bao-shan

2016-02-01

Degenerative disc disease (DDD) is the major cause of low back pain, which usually leads to work absenteeism, medical visits and hospitalization. Because the current conservative procedures and surgical approaches to treatment of DDD only aim to relieve the symptoms of disease but not to regenerate the diseased disc, their long-term efficiency is limited. With the rapid developments in medical science, tissue engineering techniques have progressed markedly in recent years, providing a novel regenerative strategy for managing intervertebral disc disease. However, there are as yet no ideal methods for constructing tissue-engineered intervertebral discs. This paper reviews published reports pertaining to intervertebral disc tissue engineering and summarizes data concerning the seed cells and scaffold materials for tissue-engineered intervertebral discs, construction of tissue-engineered whole intervertebral discs, relevant animal experiments and effects of mechanics on the construction of tissue-engineered intervertebral disc and outlines the existing problems and future directions. Although the perfect regenerative strategy for treating DDD has not yet been developed, great progress has been achieved in the construction of tissue-engineered intervertebral discs. It is believed that ongoing research on intervertebral disc tissue engineering will result in revolutionary progress in the treatment of DDD. © 2016 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

Formation of precessing jets by tilted black hole discs in 3D general relativistic MHD simulations

NASA Astrophysics Data System (ADS)

Liska, M.; Hesp, C.; Tchekhovskoy, A.; Ingram, A.; van der Klis, M.; Markoff, S.

2018-02-01

Gas falling into a black hole (BH) from large distances is unaware of BH spin direction, and misalignment between the accretion disc and BH spin is expected to be common. However, the physics of tilted discs (e.g. angular momentum transport and jet formation) is poorly understood. Using our new GPU-accelerated code H-AMR, we performed 3D general relativistic magnetohydrodynamic simulations of tilted thick accretion discs around rapidly spinning BHs, at the highest resolution to date. We explored the limit where disc thermal pressure dominates magnetic pressure, and showed for the first time that, for different magnetic field strengths on the BH, these flows launch magnetized relativistic jets propagating along the rotation axis of the tilted disc (rather than of the BH). If strong large-scale magnetic flux reaches the BH, it bends the inner few gravitational radii of the disc and jets into partial alignment with the BH spin. On longer time-scales, the simulated disc-jet system as a whole undergoes Lense-Thirring precession and approaches alignment, demonstrating for the first time that jets can be used as probes of disc precession. When the disc turbulence is well resolved, our isolated discs spread out, causing both the alignment and precession to slow down.

Extended transiting discs and rings around planets and brown dwarfs: theoretical constraints

NASA Astrophysics Data System (ADS)

Zanazzi, J. J.; Lai, Dong

2017-02-01

Newly formed planets (or brown dwarfs) may possess discs or rings which occupy an appreciable fraction of the planet's Hill sphere and extend beyond the Laplace radius, where the tidal torque from the host star dominates over the torque from the oblate planet. Such a disc/ring can exhibit unique, detectable transit signatures, provided that the disc/ring is significantly misaligned with the orbital plane of the planet. There exists tentative evidence for an extended ring system around the young K5 star 1 SWASP J140747-354542. We present a general theoretical study of the inclination (warp) profile of circumplanetary discs under the combined influences of the tidal torque from the central star, the torque from the oblate planet, and the self-gravity of the disc. We calculate the equilibrium warp profile (`generalized Laplace surface') and investigate the condition for coherent precession of the disc. We find that to maintain a non-negligible misalignment between the extended outer disc and the planet's orbital plane, and to ensure coherent disc precession, the disc surface density must be sufficiently large so that the self-gravity torque overcomes the tidal torque from the central star. Our analysis and quantitative results can be used to constrain the parameters of transiting circumplanetary discs which may be detected in the future.

The Diversity of Assembly Histories Leading to Disc Galaxy Formation in a ΛCDM Model

NASA Astrophysics Data System (ADS)

Font, Andreea S.; McCarthy, Ian G.; Le Brun, Amandine M. C.; Crain, Robert A.; Kelvin, Lee S.

2017-11-01

Disc galaxies forming in a LambdaCDM cosmology often experience violent mergers. The fact that disc galaxies are ubiquitous suggests that quiescent histories are not necessary. Modern cosmological simulations can now obtain realistic populations of disc galaxies, but it is still unclear how discs manage to survive massive mergers. Here we use a suite of hydrodynamical cosmological simulations to elucidate the fate of discs encountering massive mergers. We follow the changes in the post-merger disc-to-total ratios (D/T) of simulated galaxies and examine the relations between their present-day morphology, assembly history and gas fractions. We find that approximately half of present-day disc galaxies underwent at least one merger with a satellite more massive the host's stellar component and a third had mergers with satellites three times as massive. These mergers lead to a sharp, but often temporary, decrease in the D/T of the hosts, implying that discs are usually disrupted but then quickly re-grow. To do so, high cold gas fractions are required post-merger, as well as a relatively quiescent recent history (over a few Gyrs before z = 0). Our results show that discs can form via diverse merger pathways and that quiescent histories are not the dominant mode of disc formation.

Senescent intervertebral disc cells exhibit perturbed matrix homeostasis phenotype.

PubMed

Ngo, Kevin; Patil, Prashanti; McGowan, Sara J; Niedernhofer, Laura J; Robbins, Paul D; Kang, James; Sowa, Gwendolyn; Vo, Nam

2017-09-01

Aging greatly increases the risk for intervertebral disc degeneration (IDD) as a result of proteoglycan loss due to reduced synthesis and enhanced degradation of the disc matrix proteoglycan (PG). How disc matrix PG homeostasis becomes perturbed with age is not known. The goal of this study is to determine whether cellular senescence is a source of this perturbation. We demonstrated that disc cellular senescence is dramatically increased in the DNA repair-deficient Ercc1 -/Δ mouse model of human progeria. In these accelerated aging mice, increased disc cellular senescence is closely associated with the rapid loss of disc PG. We also directly examine PG homeostasis in oxidative damage-induced senescent human cells using an in vitro cell culture model system. Senescence of human disc cells treated with hydrogen peroxide was confirmed by growth arrest, senescence-associated β-galactosidase activity, γH2AX foci, and acquisition of senescence-associated secretory phenotype. Senescent human disc cells also exhibited perturbed matrix PG homeostasis as evidenced by their decreased capacity to synthesize new matrix PG and enhanced degradation of aggrecan, a major matrix PG. of the disc. Our in vivo and in vitro findings altogether suggest that disc cellular senescence is an important driver of PG matrix homeostatic perturbation and PG loss. Published by Elsevier B.V.

Can Commercial Digital Cameras Be Used as Multispectral Sensors? A Crop Monitoring Test.

PubMed

Lebourgeois, Valentine; Bégué, Agnès; Labbé, Sylvain; Mallavan, Benjamin; Prévot, Laurent; Roux, Bruno

2008-11-17

The use of consumer digital cameras or webcams to characterize and monitor different features has become prevalent in various domains, especially in environmental applications. Despite some promising results, such digital camera systems generally suffer from signal aberrations due to the on-board image processing systems and thus offer limited quantitative data acquisition capability. The objective of this study was to test a series of radiometric corrections having the potential to reduce radiometric distortions linked to camera optics and environmental conditions, and to quantify the effects of these corrections on our ability to monitor crop variables. In 2007, we conducted a five-month experiment on sugarcane trial plots using original RGB and modified RGB (Red-Edge and NIR) cameras fitted onto a light aircraft. The camera settings were kept unchanged throughout the acquisition period and the images were recorded in JPEG and RAW formats. These images were corrected to eliminate the vignetting effect, and normalized between acquisition dates. Our results suggest that 1) the use of unprocessed image data did not improve the results of image analyses; 2) vignetting had a significant effect, especially for the modified camera, and 3) normalized vegetation indices calculated with vignetting-corrected images were sufficient to correct for scene illumination conditions. These results are discussed in the light of the experimental protocol and recommendations are made for the use of these versatile systems for quantitative remote sensing of terrestrial surfaces.

First Image Products from EcoSAR - Osa Peninsula, Costa Rica

NASA Technical Reports Server (NTRS)

Osmanoglu, Batuhan; Lee, SeungKuk; Rincon, Rafael; Fatuyinbo, Lola; Bollian, Tobias; Ranson, Jon

2016-01-01

Designed especially for forest ecosystem studies, EcoSAR employs state-of-the-art digital beamforming technology to generate wide-swath, high-resolution imagery. EcoSARs dual antenna single-pass imaging capability eliminates temporal decorrelation from polarimetric and interferometric analysis, increasing the signal strength and simplifying models used to invert forest structure parameters. Antennae are physically separated by 25 meters providing single pass interferometry. In this mode the radar is most sensitive to topography. With 32 active transmit and receive channels, EcoSARs digital beamforming is an order of magnitude more versatile than the digital beamforming employed on the upcoming NISAR mission. EcoSARs long wavelength (P-band, 435 MHz, 69 cm) measurements can be used to simulate data products for ESAs future BIOMASS mission, allowing scientists to develop algorithms before the launch of the satellite. EcoSAR can also be deployed to collect much needed data where BIOMASS satellite wont be allowed to collect data (North America, Europe and Arctic), filling in the gaps to keep a watchful eye on the global carbon cycle. EcoSAR can play a vital role in monitoring, reporting and verification schemes of internationals programs such as UN-REDD (United Nations Reducing Emissions from Deforestation and Degradation) benefiting global society. EcoSAR was developed and flown with support from NASA Earth Sciences Technology Offices Instrument Incubator Program.

26 CFR 1.921-1T - Temporary regulations providing transition rules for DISCs and FSCs.

Code of Federal Regulations, 2010 CFR

2010-04-01

... a DISC's taxable year? A-1: Without regard to the annual accounting period of the DISC, the last... distribution of previously taxed income have on the earnings and profits of corporate shareholders of the former DISC? A-8: The earnings and profits of the corporate shareholders of the former DISC will be...

Trapping of low-mass planets outside the truncated inner edges of protoplanetary discs

NASA Astrophysics Data System (ADS)

Miranda, Ryan; Lai, Dong

2018-02-01

We investigate the migration of a low-mass (≲10 M⊕) planet near the inner edge of a protoplanetary disc using two-dimensional viscous hydrodynamics simulations. We employ an inner boundary condition representing the truncation of the disc at the stellar corotation radius. As described by Tsang, wave reflection at the inner disc boundary modifies the Type I migration torque on the planet, allowing migration to be halted before the planet reaches the inner edge of the disc. For low-viscosity discs (α ≲ 10-3), planets may be trapped with semi-major axes as large as three to five times the inner disc radius. In general, planets are trapped closer to the inner edge as either the planet mass or the disc viscosity parameter α increases, and farther from the inner edge as the disc thickness is increased. This planet trapping mechanism may impact the formation and migration history of close-in compact multiplanet systems.

Correlation between direction and severity of temporomandibular joint disc displacement and reduction ability during mouth opening.

PubMed

Litko, M; Berger, M; Szkutnik, J; Różyło-Kalinowska, I

2017-12-01

The most common temporomandibular joint (TMJ) internal derangement is an abnormal relationship of the disc with respect to the mandibular condyle, articular eminence and glenoid fossa-disc displacement. The aim of our study was to analyse the correlation between partial/complete disc displacement in the intercuspal position (IP) and its reduction in the open-mouth position (OMP) in both oblique sagittal and coronal planes on magnetic resonance imaging (MRI) in patients with temporomandibular disorders. Multisection MRI analysis of 382 TMJs was conducted in 191 patients with disc displacement according to the RDC/TMD criteria (148 women, 43 men; aged 14-60 years). The disc position was evaluated on all oblique sagittal and coronal images in the IP and the OMP. Univariate logistic regression analysis showed that the severity of disc displacement in the sagittal plane is a statistically significant predictor of reduction ability during mouth opening (B = 3.118; P < .001). Moreover, the severity of disc displacement in both planes is also a significant predictor of disc reduction in OMP (B = 2.200; P < .05). In conclusion, reduction ability during mouth opening is associated with the severity of disc displacement in IP, in both sagittal and coronal planes. Multisection analysis of all MR images allows distinguishing the correct disc position from disc displacement and can improve the ability to distinguish between various stages of TMJ internal derangement. © 2017 John Wiley & Sons Ltd.

Comparison of Optic Disc Margin Identified by Color Disc Photography and High-Speed Ultrahigh-Resolution Optical Coherence Tomography

PubMed Central

Manassakorn, Anita; Ishikawa, Hiroshi; Kim, Jong S.; Wollstein, Gadi; Bilonick, Richard A.; Kagemann, Larry; Gabriele, Michelle L.; Sung, Kyung Rim; Mumcuoglu, Tarkan; Duker, Jay S.; Fujimoto, James G.; Schuman, Joel S.

2009-01-01

Objective To determine the correspondence between optic disc margins evaluated using disc photography (DP) and optical coherence tomography (OCT). Methods From May 1, 2005, through November 10, 2005, 17 healthy volunteers (17 eyes) had raster scans (180 frames, 501 samplings per frame) centered on the optic disc taken with stereo-optic DP and high-speed ultrahigh-resolution OCT (hsUHR-OCT). Two image outputs were derived from the hsUHR-OCT data set: an en face hsUHR-OCT fundus image and a set of 180 frames of cross-sectional images. Three ophthalmologists independently and in a masked, randomized fashion marked the disc margin on the DP, hsUHR-OCT fundus, and cross-sectional images using custom software. Disc size (area and horizontal and vertical diameters) and location of the geometric disc center were compared among the 3 types of images. Results The hsUHR-OCT fundus image definition showed a significantly smaller disc size than the DP definition (P<.001, mixed-effects analysis). The hsUHR-OCT cross-sectional image definition showed a significantly larger disc size than the DP definition (P<.001). The geometric disc center location was similar among the 3 types of images except for the y-coordinate, which was significantly smaller in the hsUHR-OCT fundus images than in the DP images. Conclusion The optic disc margin as defined by hsUHR-OCT was significantly different than the margin defined by DP. PMID:18195219

Instability of warped discs

NASA Astrophysics Data System (ADS)

Doǧan, S.; Nixon, C. J.; King, A. R.; Pringle, J. E.

2018-05-01

Accretion discs are generally warped. If a warp in a disc is too large, the disc can `break' apart into two or more distinct planes, with only tenuous connections between them. Further, if an initially planar disc is subject to a strong differential precession, then it can be torn apart into discrete annuli that precess effectively independently. In previous investigations, torque-balance formulae have been used to predict where and when the disc breaks into distinct parts. In this work, focusing on discs with Keplerian rotation and where the shearing motions driving the radial communication of the warp are damped locally by turbulence (the `diffusive' regime), we investigate the stability of warped discs to determine the precise criterion for an isolated warped disc to break. We find and solve the dispersion relation, which, in general, yields three roots. We provide a comprehensive analysis of this viscous-warp instability and the emergent growth rates and their dependence on disc parameters. The physics of the instability can be understood as a combination of (1) a term that would generally encapsulate the classical Lightman-Eardley instability in planar discs (given by ∂(νΣ)/∂Σ < 0) but is here modified by the warp to include ∂(ν1|ψ|)/∂|ψ| < 0, and (2) a similar condition acting on the diffusion of the warp amplitude given in simplified form by ∂(ν2|ψ|)/∂|ψ| < 0. We discuss our findings in the context of discs with an imposed precession, and comment on the implications for different astrophysical systems.

DISC1 Protein Regulates γ-Aminobutyric Acid, Type A (GABAA) Receptor Trafficking and Inhibitory Synaptic Transmission in Cortical Neurons.

PubMed

Wei, Jing; Graziane, Nicholas M; Gu, Zhenglin; Yan, Zhen

2015-11-13

Association studies have suggested that Disrupted-in-Schizophrenia 1 (DISC1) confers a genetic risk at the level of endophenotypes that underlies many major mental disorders. Despite the progress in understanding the significance of DISC1 at neural development, the mechanisms underlying DISC1 regulation of synaptic functions remain elusive. Because alterations in the cortical GABA system have been strongly linked to the pathophysiology of schizophrenia, one potential target of DISC1 that is critically involved in the regulation of cognition and emotion is the GABAA receptor (GABAAR). We found that cellular knockdown of DISC1 significantly reduced GABAAR-mediated synaptic and whole-cell current, whereas overexpression of wild-type DISC1, but not the C-terminal-truncated DISC1 (a schizophrenia-related mutant), significantly increased GABAAR currents in pyramidal neurons of the prefrontal cortex. These effects were accompanied by DISC1-induced changes in surface GABAAR expression. Moreover, the regulation of GABAARs by DISC1 knockdown or overexpression depends on the microtubule motor protein kinesin 1 (KIF5). Our results suggest that DISC1 exerts an important effect on GABAergic inhibitory transmission by regulating KIF5/microtubule-based GABAAR trafficking in the cortex. The knowledge gained from this study would shed light on how DISC1 and the GABA system are linked mechanistically and how their interactions are critical for maintaining a normal mental state. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Revolution evolution: tracing angular momentum during star and planetary system formation

NASA Astrophysics Data System (ADS)

Davies, Claire Louise

2015-04-01

Stars form via the gravitational collapse of molecular clouds during which time the protostellar object contracts by over seven orders of magnitude. If all the angular momentum present in the natal cloud was conserved during collapse, stars would approach rotational velocities rapid enough to tear themselves apart within just a few Myr. In contrast to this, observations of pre-main sequence rotation rates are relatively slow (∼ 1 - 15 days) indicating that significant quantities of angular momentum must be removed from the star. I use observations of fully convective pre-main sequence stars in two well-studied, nearby regions of star formation (namely the Orion Nebula Cluster and Taurus-Auriga) to determine the removal rate of stellar angular momentum. I find the accretion disc-hosting stars to be rotating at a slower rate and contain less specific angular momentum than the disc-less stars. I interpret this as indicating a period of accretion disc-regulated angular momentum evolution followed by near-constant rotational evolution following disc dispersal. Furthermore, assuming that the age spread inferred from the Hertzsprung-Russell diagram constructed for the star forming region is real, I find that the removal rate of angular momentum during the accretion-disc hosting phase to be more rapid than that expected from simple disc-locking theory whereby contraction occurs at a fixed rotation period. This indicates a more efficient process of angular momentum removal must operate, most likely in the form of an accretion-driven stellar wind or outflow emanating from the star-disc interaction. The initial circumstellar envelope that surrounds a protostellar object during the earliest stages of star formation is rotationally flattened into a disc as the star contracts. An effective viscosity, present within the disc, enables the disc to evolve: mass accretes inwards through the disc and onto the star while momentum migrates outwards, forcing the outer regions of the disc to expand. I used spatially resolved submillimetre detections of the dust and gas components of protoplanetary discs, gathered from the literature, to measure the radial extent of discs around low-mass pre-main sequence stars of ∼ 1-10 Myr and probe their viscous evolution. I find no clear observational evidence for the radial expansion of the dust component. However, I find tentative evidence for the expansion ofthe gas component. This suggests that the evolution of the gas and dust components of protoplanetary discs are likely governed by different astrophysical processes. Observations of jets and outflows emanating from protostars and pre-main sequence stars highlight that it may also be possible to remove angular momentum from the circumstellar material. Using the sample of spatially resolved protoplanetary discs, I find no evidence for angular momentum removal during disc evolution. I also use the spatially resolved debris discs from the Submillimetre Common-User Bolometer Array-2 Observations of Nearby Stars survey to constrain the amount of angular momentum retained within planetary systems. This sample is compared to the protoplanetary disc angular momenta and to the angular momentum contained within pre-stellar cores. I find that significant quantities of angular momentum must be removed during disc formation and disc dispersal. This likely occurs via magnetic braking during the formation of the disc, via the launching of a disc or photo-evaporative wind, and/or via ejection of planetary material following dynamical interactions.

Rossby wave instability in astrophysical discs

NASA Astrophysics Data System (ADS)

Lovelace, R. V. E.; Romanova, M. M.

2014-08-01

A brief review is given of the Rossby wave instability in astrophysical discs. In non-self-gravitating discs, around for example a newly forming stars, the instability can be triggered by an axisymmetric bump at some radius r0 in the disc surface mass-density. It gives rise to exponentially growing non-axisymmetric perturbation (\\propto \\exp \\,({ { i}}m\\phi ) , m = 1,2,…) in the vicinity of r0 consisting of anticyclonic vortices. These vortices are regions of high pressure and consequently act to trap dust particles which in turn can facilitate planetesimal growth in proto-planetary discs. The Rossby vortices in the discs around stars and black holes may cause the observed quasi-periodic modulations of the disc's thermal emission.

[Effect of medicinal-cake-separated moxibustion on functional activity of back-leg and plasma substance P level in patients with lumbar disc herniation].

PubMed

Yang, Shuo; Yang, Xiao-fang; Jiang, Yu; Xiang, Kai-wei; Li, Hai-yu

2014-12-01

To observe the effect of medicinal-cake-separated moxibustion combined with acupuncture on back-leg activities and plasma substance P (SP) levels in patients with lumbar disc herniation, so as to reveal its mechanism underlying pain relief. A total of 114 patients with lumbar disc herniation were randomly divided into control group (n=56) and treatment group (n=58) according to a random digits table. Patients of the control group were treated by manual acupuncture stimulation of main acupoints Jiaji (EX-B 2), Huantiao (GB 30, affected side), Chengshan (BL 57, affected side), Kunlun (BL 60, affected side), and supplemented acupoints Yanglingquan (GB 34), Weizhong (BL 40) and Zusanli (ST 36) in combination with wheat-flour-cake separated moxibustion at the main acupoints, and patients of the treatment group were treated by medicinal-cake [Chuanwu (Radix Aconiti), Caowu (Radix Aconiti Kusnezoffii), Ruxiang (Olibanum), etc. ]-separated moxibustion in combination with manual acupuncture stimulation of the same acupoints mentioned above. Acupuncture treatment was conducted for 30 min, followed by moxibustion for 15 min. The treatment was given once daily for 10 days. The patients' back-leg functional activity ability was assessed using straight-leg raising test, and the pain state assessed using visual analogue scale (VAS) and Japanese Orthopaedic Association (JOA) scores, respectively. The therapeutic effect was evaluated by using "Crite- ria for Diagnosis and Outcome Evaluation of Clinical Disorders or Syndromes of Chinese Medicine" issued in 1994 and plasma SP content was detected by radioimmunoassay. After the therapy, the back-leg activity score and JOA score of both groups were significantly higher than those of pre-treatment in the same one group (P<0. 05, P<0. 01), and those of the treatment group were significantly higher than those of the control group (P<0.05). The VAS score of the treatment group was re- markably lower than that of the control group (P<0. 01). After the treatment, the plasma SP content was markedly lower in the treatment group than in the control group (.P<0O. 05 ) . Medicinal-cake-separated moxibustion therapy can ame- liorate pain severity and functional activity of the back-leg pain patients with lumbar disc hernia, which may be related to its effect in reducing blood SP level.

Disc Golf: Teaching a Lifetime Activity

ERIC Educational Resources Information Center

Eastham, Susan L.

2015-01-01

Disc golf is a lifetime activity that can be enjoyed by students of varying skill levels and abilities. Disc golf follows the principles of ball golf but is generally easier for students to play and enjoy success. The object of disc golf is similar to ball golf and involves throwing a disc from the teeing area to the target in as few throws as…

26 CFR 1.995-1 - Taxation of DISC income to shareholders.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 10 2011-04-01 2011-04-01 false Taxation of DISC income to shareholders. 1.995... Taxation of DISC income to shareholders. (a) In general. (1) Under § 1.991-1(a), a corporation which is a... DISC, are subject to taxation on the earnings and profits of the DISC in accordance with the provisions...

Modeling and optimization of an elastic arthroplastic disc for a degenerated disc

NASA Astrophysics Data System (ADS)

Ghouchani, Azadeh; Ravari, Mohammad; Mahmoudi, Farid

2011-10-01

A three-dimensional finite element model (FEM) of the L3-L4 motion segment using ABAQUS v 6.9 has been developed. The model took into account the material nonlinearities and is imposed different loading conditions. In this study, we validated the model by comparison of its predictions with several sets of experimental data. Disc deformation under compression and segmental rotational motions under moment loads for the normal disc model agreed well with the corresponding in vivo studies. By linking ABAQUS with MATLAB 2010.a, we determined the optimal Young s modulus as well as the Poisson's ratio for the artificial disc under different physiologic loading conditions. The results of the present study confirmed that a well-designed elastic arthroplastic disc preferably has an annulus modulus of 19.1 MPa and 1.24 MPa for nucleus section and Poisson ratio of 0.41 and 0.47 respectively. Elastic artificial disc with such properties can then achieve the goal of restoring the disc height and mechanical function of intact disc under different loading conditions and so can reduce low back pain which is mostly caused due to disc degeneration.

Evaluation of Electrospun Nanofiber-Anchored Silicone for the Degenerative Intervertebral Disc

PubMed Central

Riahanizad, S.

2017-01-01

The nucleus pulposus (NP) substitution by polymeric gel is one of the promising techniques for the repair of the degenerative intervertebral disc (IVD). Silicone gel is one of the potential candidates for a NP replacement material. Electrospun fiber anchorage to silicone disc, referred as ENAS disc, may not only improve the biomechanical performances of the gel but it can also improve restoration capability of the gel, which is unknown. This study successfully produced a novel process to anchor any size and shape of NP gel with electrospun fiber mesh. Viscoelastic properties of silicone and ENAS disc were measured using standard experimental techniques and compared with the native tissue properties. Ex vivo mechanical tests were conducted on ENAS disc-implanted rabbit tails to the compare the mechanical stability between intact and ENAS implanted spines. This study found that viscoelastic properties of ENAS disc are higher than silicone disc and comparable to the viscoelastic properties of human NP. The ex vivo studies found that the ENAS disc restore the mechanical functionality of rabbit tail spine, after discectomy of native NP and replacing the NP by ENAS disc. Therefore, the PCL ENF mesh anchoring technique to a NP implant can have clinical potential. PMID:29181144

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

Chillara, Vamshi Krishna; Pantea, Cristian; Sinha, Dipen N.

Here, we numerically investigate the resonance and vibration characteristics of radial modes of laterally stiffened piezoelectric disc transducers. Lateral stiffening is modeled using a spring and vibration characteristics of the piezo-disc are investigated with increasing lateral stiffness. It is found that the resonant frequency response of the radial modes follows an asymptotic behavior approaching that of a clamped disc with increasing lateral stiffness. The radial mode vibration pattern of the discs is also found to be affected by lateral stiffness. While the vibration pattern of a free disc corresponds to a Bessel function, laterally stiffened discs show edge-effects where theymore » depart from the Bessel-like behavior. In addition, a fully clamped piezo-disc is found to have an extra side-lobe when compared to a free disc. Ultrasonic beam profiles generated from radial modes of laterally stiffened discs are numerically investigated. It is found that the free piezo-disc generates a Bessel beam that has multiple side-lobes. Increasing the lateral stiffness results in a significant reduction of side-lobes in the beam profile. This technique of generating a collimated beam with side-lobe reduction finds significant applications in imaging through concrete, drilling mud, and other highly attenuating materials.« less

Fragmentation of protoplanetary discs around M-dwarfs

NASA Astrophysics Data System (ADS)

Backus, Isaac; Quinn, Thomas

2016-12-01

We investigate the conditions required for planet formation via gravitational instability (GI) and protoplanetary disc (PPD) fragmentation around M-dwarfs. Using a suite of 64 SPH simulations with 106 particles, the parameter space of disc mass, temperature, and radius is explored, bracketing reasonable values based on theory and observation. Our model consists of an equilibrium, gaseous, and locally isothermal disc orbiting a central star of mass M* = M⊙/3. Discs with a minimum Toomre Q of Qmin ≲ 0.9 will fragment and form gravitationally bound clumps. Some previous literature has found Qmin < 1.3-1.5 to be sufficient for fragmentation. Increasing disc height tends to stabilize discs, and when incorporated into Q as Qeff ∝ Q(H/R)α for α = 0.18 is sufficient to predict fragmentation. Some discrepancies in the literature regarding Qcrit may be due to different methods of generating initial conditions (ICs). A series of 15 simulations demonstrates that perturbing ICs slightly out of equilibrium can cause discs to fragment for higher Q. Our method for generating ICs is presented in detail. We argue that GI likely plays a role in PPDs around M-dwarfs and that disc fragmentation at large radii is a plausible outcome for these discs.

Spontaneous regression of posterior epidural migrated lumbar disc fragments: case series.

PubMed

Tarukado, Kiyoshi; Ikuta, Ko; Fukutoku, Yoshiaki; Tono, Osamu; Doi, Toshio

2015-06-01

Posterior epidural migrated lumbar disc fragments is an extremely rare disorder. Surgical treatment was performed in all reported cases. To the best of our knowledge, there are no reported cases of the use of conservative treatment for posterior epidural migrated lumbar disc fragments. To report the possibility of a spontaneous regression of posterior epidural migrated lumbar disc fragments. Case series. Four patients with posterior epidural migrated lumbar disc fragments were treated at Karatsu Red Cross Hospital between April 2008 and August 2010. Spontaneous regression of the posterior epidural migrated lumbar disc fragments with relief of symptoms was observed on magnetic resonance imaging (MRI) in three cases. Another patient underwent surgical treatment. The present and previously reported cases of posterior epidural migrated lumbar disc fragments were analyzed with respect to patient age, imaging features on MRI, the level of the lesion, clinical symptoms, treatment, and outcomes. Conservative treatment was successful, and spontaneous lesion regression was seen on MRI with symptom relief in three cases. Although posterior epidural migrated lumbar disc fragment cases are generally treated surgically, the condition can regress spontaneously over time, as do sequestrated disc fragments. Spontaneous regression of lumbar disc herniations is a widely accepted observation at present. Posterior epidural migrated lumbar disc fragments fall under the sequestrated type of disc herniation. In fact, the course of treatment for posterior epidural migrated lumbar disc fragments should be determined based on the symptoms and examination findings, as in cases of ordinary herniation. However, providing early surgical treatment is important if the patient has acute cauda equina syndrome or the neurologic symptoms worsen over time. Copyright © 2015 Elsevier Inc. All rights reserved.

Disrupted-in-Schizophrenia-1 Attenuates Amyloid-β Generation and Cognitive Deficits in APP/PS1 Transgenic Mice by Reduction of β-Site APP-Cleaving Enzyme 1 Levels

PubMed Central

Deng, Qing-Shan; Dong, Xing-Yu; Wu, Hao; Wang, Wang; Wang, Zhao-Tao; Zhu, Jian-Wei; Liu, Chun-Feng; Jia, Wei-Qiang; Zhang, Yan; Schachner, Melitta; Ma, Quan-Hong; Xu, Ru-Xiang

2016-01-01

Disrupted-in-Schizophrenia-1 (DISC1) is a genetic risk factor for a wide range of major mental disorders, including schizophrenia, major depression, and bipolar disorders. Recent reports suggest a potential role of DISC1 in the pathogenesis of Alzheimer's disease (AD), by referring to an interaction between DISC1 and amyloid precursor protein (APP), and to an association of a single-nucleotide polymorphism in a DISC1 intron and late onset of AD. However, the function of DISC1 in AD remains unknown. In this study, decreased levels of DISC1 were observed in the cortex and hippocampus of 8-month-old APP/PS1 transgenic mice, an animal model of AD. Overexpression of DISC1 reduced, whereas knockdown of DISC1 increased protein levels, but not mRNA levels of β-site APP-Cleaving Enzyme 1 (BACE1), a key enzyme in amyloid-β (Aβ) generation. Reduction of BACE1 protein levels by overexpression of DISC1 was accompanied by an accelerating decline rate of BACE1, and was blocked by the lysosomal inhibitor chloroquine, rather than proteasome inhibitor MG-132. Moreover, overexpression of DISC1 in the hippocampus with an adeno-associated virus reduced the levels of BACE1, soluble Aβ40/42, amyloid plaque density, and rescued cognitive deficits of APP/PS1 transgenic mice. These results indicate that DISC1 attenuates Aβ generation and cognitive deficits of APP/PS1 transgenic mice through promoting lysosomal degradation of BACE1. Our findings provide new insights into the role of DISC1 in AD pathogenesis and link a potential function of DISC1 to the psychiatric symptoms of AD. PMID:26062786

Rat Disc Torsional Mechanics: Effect of Lumbar and Caudal Levels and Axial Compression Load

PubMed Central

Elliott, Dawn M; Espinoza Orías, Alejandro A; Malhotra, Neil R

2009-01-01

Background Context Rat models with altered loading are used to study disc degeneration and mechano-transduction. Given the prominent role of mechanics in disc function and degeneration, it is critical to measure mechanical behavior in order to evaluate changes following model interventions. Axial compression mechanics of the rat disc are representative of the human disc when normalized by geometry, and differences between the lumbar and caudal disc have been quantified in axial compression. No study has quantified rat disc torsional mechanics. Purpose Compare the torsional mechanical behavior of rat lumbar and caudal discs, determine the contribution of combined axial load on torsional mechanics, and compare the torsional properties of rat discs to human lumbar discs. Study Design Cadaveric biomechanical study. Methods Cyclic torsion without compressive load followed by cyclic torsion with a fixed compressive load was applied to rat lumbar and caudal disc levels. Results The apparent torsional modulus was higher in the lumbar region than in the caudal region,: 0.081±0.026 (MPa/°, Mean±SD) for lumbar axially loaded; 0.066±0.028 caudal axially loaded; 0.091±0.033 for lumbar in pure torsion; and 0.056±0.035 for caudal in pure torsion. These values were similar to human disc properties reported in the literature ranging from 0.024 to 0.21 MPa/°. Conclusions Use of the caudal disc as a model may be appropriate if the mechanical focus is within the linear region of the loading regime. These results provide support for use of this animal model in basic science studies with respect to torsional mechanics. PMID:18495544

Adjacent level effects of bi level disc replacement, bi level fusion and disc replacement plus fusion in cervical spine--a finite element based study.

PubMed

Faizan, Ahmad; Goel, Vijay K; Biyani, Ashok; Garfin, Steven R; Bono, Christopher M

2012-03-01

Studies delineating the adjacent level effect of single level disc replacement systems have been reported in literature. The aim of this study was to compare the adjacent level biomechanics of bi-level disc replacement, bi-level fusion and a construct having adjoining level disc replacement and fusion system. In total, biomechanics of four models- intact, bi level disc replacement, bi level fusion and fusion plus disc replacement at adjoining levels- was studied to gain insight into the effects of various instrumentation systems on cranial and caudal adjacent levels using finite element analysis (73.6N+varying moment). The bi-level fusion models are more than twice as stiff as compared to the intact model during flexion-extension, lateral bending and axial rotation. Bi-level disc replacement model required moments lower than intact model (1.5Nm). Fusion plus disc replacement model required moment 10-25% more than intact model, except in extension. Adjacent level motions, facet loads and endplate stresses increased substantially in the bi-level fusion model. On the other hand, adjacent level motions, facet loads and endplate stresses were similar to intact for the bi-level disc replacement model. For the fusion plus disc replacement model, adjacent level motions, facet loads and endplate stresses were closer to intact model rather than the bi-level fusion model, except in extension. Based on our finite element analysis, fusion plus disc replacement procedure has less severe biomechanical effects on adjacent levels when compared to bi-level fusion procedure. Bi-level disc replacement procedure did not have any adverse mechanical effects on adjacent levels. Copyright © 2011 Elsevier Ltd. All rights reserved.

Changes in intervertebral disc cross-sectional area with bed rest and space flight

NASA Technical Reports Server (NTRS)

LeBlanc, A. D.; Evans, H. J.; Schneider, V. S.; Wendt, R. E. 3rd; Hedrick, T. D.

1994-01-01

STUDY DESIGN. We measured the cross-sectional area of the intervertebral discs of normal volunteers after an overnight rest; before, during, and after 5 or 17 weeks of bed rest; and before and after 8 days of weightlessness. OBJECTIVES. This study sought to determine the degree of expansion of the lumbar discs resulting from bed rest and space flight. SUMMARY OF BACKGROUND DATA. Weightlessness and bed rest, an analog for weightlessness, reduce the mechanical loading on the musculoskeletal system. When unloaded, intervertebral discs will expand, increasing the nutritional diffusion distance and altering the mechanical properties of the spine. METHODS. Magnetic resonance imaging was used to measure the cross-sectional area and transverse relaxation time (T2) of the intervertebral discs. RESULTS. Overnight or longer bed rest causes expansion of the disc area, which reaches an equilibrium value of about 22% (range 10-40%) above baseline within 4 days. Increases in disc area were associated with modest increases in disc T2. During bed rest, disc height increased approximately 1 mm, about one-half of previous estimates based on body height measurements. After 5 weeks of bed rest, disc area returned to baseline within a few days of ambulation, whereas after 17 weeks, disc area remained above baseline 6 weeks after reambulation. After 8 days of weightlessness, T2, disc area, and lumbar length were not significantly different from baseline values 24 hours after landing. CONCLUSIONS. Significant adaptive changes in the intervertebral discs can be expected during weightlessness. These changes, which are rapidly reversible after short-duration flights, may be an important factor during and after long-duration missions.

The comparative analysis of rocks' resistance to forward-slanting disc cutters and traditionally installed disc cutters

NASA Astrophysics Data System (ADS)

Zhang, Zhao-Huang; Fei, Sun; Liang, Meng

2016-08-01

At present, disc cutters of a full face rock tunnel boring machine are mostly mounted in the traditional way. Practical use in engineering projects reveals that this installation method not only heavily affects the operation life of disc cutters, but also increases the energy consumption of a full face rock tunnel boring machine. To straighten out this issue, therefore, a rock-breaking model is developed for disc cutters' movement after the research on the rock breaking of forward-slanting disc cutters. Equations of its displacement are established based on the analysis of velocity vector of a disc cutter's rock-breaking point. The functional relations then are brought forward between the displacement parameters of a rock-breaking point and its coordinate through the analysis of micro displacement of a rock-breaking point. Thus, the geometric equations of rock deformation are derived for the forward-slanting installation of disc cutters. With a linear relationship remaining between the acting force and its deformation either before or after the leap breaking, the constitutive relation of rock deformation can be expressed in the form of generalized Hooke law, hence the comparative analysis of the variation in the resistance of rock to the disc cutters mounted in the forward-slanting way with that in the traditional way. It is discovered that with the same penetration, strain of the rock in contact with forward-slanting disc cutters is apparently on the decline, in other words, the resistance of rock to disc cutters is reduced. Thus wear of disc cutters resulted from friction is lowered and energy consumption is correspondingly decreased. It will be useful for the development of installation and design theory of disc cutters, and significant for the breakthrough in the design of full face rock tunnel boring machine.

The vertical structure of gaseous galaxy discs in cold dark matter haloes

NASA Astrophysics Data System (ADS)

Benítez-Llambay, Alejandro; Navarro, Julio F.; Frenk, Carlos S.; Ludlow, Aaron D.

2018-01-01

We study the vertical structure of polytropic centrifugally supported gaseous discs embedded in cold dark matter (CDM) haloes. At fixed radius, R, the shape of the vertical density profile depends weakly on whether the disc is self-gravitating (SG) or non-self-gravitating (NSG). The disc 'characteristic' thickness, zH, set by the midplane sound speed and circular velocity, zNSG = (cs/Vc)R, in the NSG case, and by the sound speed and surface density, z_SG = c_s^2/GΣ, in SG discs, is smaller than zSG and zNSG. SG discs are typically Toomre unstable, NSG discs are stable. Exponential discs in CDM haloes with roughly flat circular velocity curves 'flare' outwards. Flares in mono abundance or coeval populations in galaxies like the Milky Way are thus not necessarily due to radial migration. For the polytropic equation of state of the Evolution and Assembly of GaLaxies and their Environments (EAGLE) simulations, discs that match observational constraints are NSG for Md < 3 × 109 M⊙ and SG at higher masses, if fully gaseous. We test these analytic results using a set of idealized smoothed particle hydrodynamic simulations and find excellent agreement. Our results clarify the role of the gravitational softening on the thickness of simulated discs, and on the onset of radial instabilities. EAGLE low-mass discs are NSG so the softening plays no role in their vertical structure. High-mass discs are expected to be SG and unstable, and may be artificially thickened and stabilized unless gravity is well resolved. Simulations with spatial resolution high enough to not compromise the vertical structure of a disc also resolve the onset of their instabilities, but the converse is not true.

Modelling the chemistry of a gravitationally unstable protoplanetary disc

NASA Astrophysics Data System (ADS)

Ilee, J. D.; Boley, A. C.; Caselli, P.; Durisen, R. H.; Hartquist, T. W.; Rawlings, J. M. C.

2011-05-01

Until now, axisymmetric, α-disc simulations have been adopted to describe the dynamics used in the construction of chemical models of protoplanetary discs. While this approach is reasonable for many discs, it is not appropriate for young, massive discs in which self-gravity is important. Spiral waves and shocks cause significant temperature and density variations which affect the chemistry. We have used a dynamical model of solar mass star surrounded by a massive (0.39 M⊙), self-gravitating disc to model the chemistry of one of these objects.

Morphological Features and Important Parameters of Large Optic Discs for Diagnosing Glaucoma

PubMed Central

Okimoto, Satoshi; Yamashita, Keiko; Shibata, Tetsuo; Kiuchi, Yoshiaki

2015-01-01

Purpose To compare the optic disc parameters of glaucomatous eyes to those of non-glaucomatous eyes with large discs. Methods We studied 225 consecutive eyes with large optic discs (>2.82 mm2): 91 eyes with glaucoma and 134 eyes without glaucoma. An eye was diagnosed with glaucoma when visual field defects were detected by the Humphrey Field Analyzer. All of the Heidelberg Retina Tomograph II (HRT II) parameters were compared between the non-glaucomatous and glaucomatous eyes. A logistic regression analysis of the HRT II parameters was used to establish a new formula for diagnosing glaucoma, and the sensitivity and specificity of the Moorfields Regression Analysis (MRA) was compared to the findings made by our analyses. Results The mean disc area was 3.44±0.50 mm2 in the non-glaucomatous group and 3.40±0.52 mm2 in the glaucoma group. The cup area, cup volume, cup-to-disc area ratio, linear cup/disc ratio, mean cup depth, and the maximum cup depth were significantly larger in glaucomatous eyes than in the non-glaucomatous eyes. The rim area, rim volume, cup shape measurement, mean retinal nerve fiber layer (RNFL) thickness, and RFNL cross-sectional area were significantly smaller in glaucomatous eyes than in non-glaucomatous eyes. The cup-to-disc area ratio, the height variation contour (HVC), and the RNFL cross-sectional area were important parameters for diagnosing the early stage glaucoma, and the cup-to-disc area ratio and cup volume were useful for diagnosing advanced stage glaucoma in eyes with a large optic disc. The new formula had higher sensitivity and specificity for diagnosing glaucoma than MRA. Conclusions The cup-to-disc area ratio, HVC, RNFL cross-sectional area, and cup volume were important parameters for diagnosing glaucoma in eyes with a large optic disc. The important disc parameters to diagnose glaucoma depend on the stage of glaucoma in patients with large discs. PMID:25798580

[In situ analysis of pathomechanisms of human intervertebral disc degeneration].

PubMed

Weiler, C

2013-11-01

Low back pain is one of the major causes of pain and disability in the western world, with a constantly rising life-time prevalence of approximately 60-85 %. Degeneration of the intervertebral disc is believed to be a major cause of low back pain. Semiquantitative macroscopic and microscopic changes of the intervertebral disc were assessed and classified. Furthermore additional methods, such as immunohistochemistry, in situ hybridization and in situ zymography were used to analyze phenotypic cellular and matrix changes. We have developed and tested a practicable, valid and reliable histological classification system for lumbar discs which can serve as a morphological reference framework to allow more sophisticated molecular biological studies on the pathogenesis of ageing and degeneration of discs. Secondly, we were able to demonstrate that intrinsic (genetic) and extrinsic (e.g. overweight) factors have a profound effect on the process of disc degeneration. Cells with a notochord-like phenotype are present in a considerable fraction of adult lumbar intervertebral discs. The presence of these cells is associated with distinct features of (early) age-related disc degeneration. During the process of disc degeneration, the intervertebral disc shows a progressive and significant reduction in height due to tissue resorption. This matrix loss is related to an imbalance between matrix synthesis and degradation. During this process an inflammatory reaction takes place and resident disc cells are causatively involved. In summary, disc degeneration is a multifactorial disease with a strong intrinsic (hereditary) and extrinsic (e.g. mechanical factors) background. The process starts as early as in the second decade of life and shows high interindividual differences. The loss of regenerative capacity in the intervertebral disc is probably related to the loss of stem cells, e.g. notochord-like cells. Resident disc cells are involved in the inflammatory reaction with increased matrix degradation, resorption and reduced matrix synthesis.

Structure and function of the temporomandibular joint disc: implications for tissue engineering.

PubMed

Detamore, Michael S; Athanasiou, Kyriacos A

2003-04-01

The temporomandibular joint (TMJ) disc is a little understood structure that, unfortunately, exhibits a plethora of pathologic disorders. Tissue engineering approaches may be warranted to address TMJ disc pathophysiology, but first a clear understanding of structure-function relationships needs to be developed, especially as they relate to the regenerative potential of the tissue. In this review, we correlate the biochemical content of the TMJ disc to its mechanical behavior and discuss what this correlation infers for tissue engineering studies of the TMJ disc. The disc of the TMJ exhibits a somewhat biconcave shape, being thicker in the anterior and posterior bands and thinner in the intermediate zone. The disc, which is certainly an anisotropic and nonhomogeneous tissue, consists almost entirely of type I collagen with trace amounts of type II and other types. In general, collagen fibers in the intermediate zone appear to run primarily in an anteroposterior direction and in a ringlike fashion around the periphery. Collagen orientation is reflected in higher tensile stiffness and strength in the center anteroposteriorly than mediolaterally and in the anterior and posterior bands than the intermediate zone mediolaterally. Tensile tests have shown the disc is stiffer and stronger in the direction of the collagen fibers. Elastin fibers in general appear along the collagen fibers and most likely function in restoring and retaining disc form after loading. The 2 primary glycosaminoglycans of the disc by far are chondroitin sulfate and dermatan sulfate, although their distribution is not clear. Compression studies are conflicting, but evidence suggests the disc is compressively stiffest in the center. Only a few tissue engineering studies of the TMJ disc have been performed to date. Tissue engineering studies must take advantage of existing information for experimental design and construct validation, and more research is necessary to characterize the disc to create a clearer picture of our goals in tissue engineering the TMJ disc. Copyright 2003 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 61:494-506, 2003

Optical Coherence Tomography Angiography of Optic Disc Perfusion in Glaucoma

PubMed Central

Jia, Yali; Wei, Eric; Wang, Xiaogang; Zhang, Xinbo; Morrison, John C.; Parikh, Mansi; Lombardi, Lori H.; Gattey, Devin M.; Armour, Rebecca L.; Edmunds, Beth; Kraus, Martin F.; Fujimoto, James G.; Huang, David

2014-01-01

Purpose To compare optic disc perfusion between normal and glaucoma subjects using optical coherence tomography (OCT) angiography and detect optic disc perfusion changes in glaucoma. Design Observational, cross-sectional study. Participants Twenty-four normal subjects and 11 glaucoma patients were included. Methods One eye of each subject was scanned by a high-speed 1050 nm wavelength swept-source OCT instrument. The split-spectrum amplitude-decorrelation angiography algorithm (SSADA) was used to compute three-dimensional optic disc angiography. A disc flow index was computed from four registered scans. Confocal scanning laser ophthalmoscopy (cSLO) was used to measure disc rim area, and stereo photography was used to evaluate cup/disc ratios. Wide field OCT scans over the discs were used to measure retinal nerve fiber layer (NFL) thickness. Main Outcome Measurements Variability was assessed by coefficient of variation (CV). Diagnostic accuracy was assessed by sensitivity and specificity. Comparisons between glaucoma and normal groups were analyzed by Wilcoxon rank-sum test. Correlations between disc flow index, structural assessments, and visual field (VF) parameters were assessed by linear regression. Results In normal discs, a dense microvascular network was visible on OCT angiography. This network was visibly attenuated in glaucoma subjects. The intra-visit repeatability, inter-visit reproducibility, and normal population variability of the optic disc flow index were 1.2%, 4.2%, and 5.0% CV respectively. The disc flow index was reduced by 25% in the glaucoma group (p = 0.003). Sensitivity and specificity were both 100% using an optimized cutoff. The flow index was highly correlated with VF pattern standard deviation (R2 = 0.752, p = 0.001). These correlations were significant even after accounting for age, cup/disc area ratio, NFL, and rim area. Conclusions OCT angiography, generated by the new SSADA algorithm, repeatably measures optic disc perfusion. OCT angiography could be useful in the evaluation of glaucoma and glaucoma progression. PMID:24629312

Counter-rotating accretion discs

NASA Astrophysics Data System (ADS)

Dyda, S.; Lovelace, R. V. E.; Ustyugova, G. V.; Romanova, M. M.; Koldoba, A. V.

2015-01-01

Counter-rotating discs can arise from the accretion of a counter-rotating gas cloud on to the surface of an existing corotating disc or from the counter-rotating gas moving radially inwards to the outer edge of an existing disc. At the interface, the two components mix to produce gas or plasma with zero net angular momentum which tends to free-fall towards the disc centre. We discuss high-resolution axisymmetric hydrodynamic simulations of viscous counter-rotating discs for the cases where the two components are vertically separated and radially separated. The viscosity is described by an isotropic α-viscosity including all terms in the viscous stress tensor. For the vertically separated components, a shear layer forms between them and the middle part of this layer free-falls to the disc centre. The accretion rates are increased by factors of ˜102-104 over that for a conventional disc rotating in one direction with the same viscosity. The vertical width of the shear layer and the accretion rate are strongly dependent on the viscosity and the mass fraction of the counter-rotating gas. In the case of radially separated components where the inner disc corotates and the outer disc rotates in the opposite direction, a gap between the two components opens and closes quasi-periodically. The accretion rates are ≳25 times larger than those for a disc rotating in one direction with the same viscosity.

Effect of Air-Polishing on Titanium Surfaces, Biofilm Removal, and Biocompatibility: A Pilot Study

PubMed Central

Bennani, Vincent; Hwang, Linda; Tawse-Smith, Andrew; Dias, George J.; Cannon, Richard D.

2015-01-01

Purpose. The aims of this in vitro study were to evaluate morphological changes induced by glycine powder air-polishing on titanium surfaces, biofilm removal, and biocompatibility. Material and Methods. Titanium grade IV discs were allocated into two groups: (1) discs without biofilm and (2) discs for Streptococcus mutans biofilm formation. Discs in each group were further subdivided into (a) no treatment and (b) air-polishing treatment with glycine powder. Discs were characterized by scanning electron microscopy (SEM), electron-dispersive spectroscopy (EDS), and confocal microscopy. Bacterial biofilms were quantified using a crystal violet dye-binding assay. Biocompatibility was evaluated by measuring the coverage and viability of L929 fibroblast cells cultured on the discs. Results. Air-polishing increased the roughness of treated discs (P < 0.05). EDS analysis did not show significant differences in the chemical composition of treated and nontreated discs. The amount of residual biofilm on treated discs was 8.6-fold lower than untreated controls (P < 0.05). Coverage of treated discs by fibroblasts was half that of untreated discs (P < 0.05) although both groups had the same cell viability. Conclusions. Air-polishing removed a significant amount of biofilm from titanium surfaces. The “polishing” was accompanied by increased surface roughness, but there were no changes in chemical and elemental compositions, nor the biocompatibility. PMID:26881198

Use NASA GES DISC Data in ArcGIS

NASA Technical Reports Server (NTRS)

Yang, Wenli; Pham, Long B.; Kempler, Steve

2015-01-01

This presentation describes GIS relevant data at NASA Goddard Earth Sciences Data and Information Services Center (GES DISC), GES DISC Services and Support for GIS Users, and use cases of GES DISC data in ArcGIS.

Accretion disc wind variability in the states of the microquasar GRS 1915+105

NASA Astrophysics Data System (ADS)

Neilsen, Joseph; Petschek, Andrew J.; Lee, Julia C.

2012-03-01

Continuing our study of the role and evolution of accretion disc winds in the microquasar GRS 1915+105, we present high-resolution spectral variability analysis of the β and γ states with the Chandra High-Energy Transmission Grating Spectrometer. By tracking changes in the absorption lines from the accretion disc wind, we find new evidence that radiation links the inner and outer accretion discs on a range of time-scales. As the central X-ray flux rises during the high-luminosity γ state, we observe the progressive overionization of the wind. In the β state, we argue that changes in the inner disc leading to the ejection of a transient 'baby jet' also quench the highly ionized wind from the outer disc. Our analysis reveals how the state, structure and X-ray luminosity of the inner accretion disc all conspire to drive the formation and variability of highly ionized accretion disc winds.

Analysis of Electrowetting Dynamics with Level Set Method

NASA Astrophysics Data System (ADS)

Park, Jun Kwon; Hong, Jiwoo; Kang, Kwan Hyoung

2009-11-01

Electrowetting is a versatile tool to handle tiny droplets and forms a backbone of digital microfluidics. Numerical analysis is necessary to fully understand the dynamics of electrowetting, especially in designing electrowetting-based liquid lenses and reflective displays. We developed a numerical method to analyze the general contact-line problems, incorporating dynamic contact angle models. The method was applied to the analysis of spreading process of a sessile droplet for step input voltages in electrowetting. The result was compared with experimental data and analytical result which is based on the spectral method. It is shown that contact line friction significantly affects the contact line motion and the oscillation amplitude. The pinning process of contact line was well represented by including the hysteresis effect in the contact angle models.

Preparing and probing many-body correlated systems in a Quantum Gas Microscope by engineering arbitrary landscape potentials

NASA Astrophysics Data System (ADS)

Rispoli, Matthew; Lukin, Alexander; Ma, Ruichao; Preiss, Philipp; Tai, M. Eric; Islam, Rajibul; Greiner, Markus

2015-05-01

Ultracold atoms in optical lattices provide a versatile tool box for observing the emergence of strongly correlated physics in quantum systems. Dynamic control of optical potentials on the single-site level allows us to prepare and probe many-body quantum states through local Hamiltonian engineering. We achieve these high precision levels of optical control through spatial light modulation with a DMD (digital micro-mirror device). This allows for both arbitrary beam shaping and aberration compensation in our imaging system to produce high fidelity optical potentials. We use these techniques to control state initialization, Hamiltonian dynamics, and measurement in experiments investigating low-dimensional many-body physics - from one-dimensional correlated quantum walks to characterizing entanglement.

Printed circuit board for a CCD camera head

DOEpatents

Conder, Alan D.

2002-01-01

A charge-coupled device (CCD) camera head which can replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating x-rays, such as within a target chamber where laser produced plasmas are studied. The camera head is small, capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, which allows for close (0.04" for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high energy density plasmas, for a variety of military industrial, and medical imaging applications.

A versatile microprocessor-controlled hybrid receiver. [with firmware control for operation over large frequency uncertainty

NASA Technical Reports Server (NTRS)

Grant, T. L.

1978-01-01

A hybrid receiver has been designed for the Galileo Project. The receiver, located on the Galileo Orbiter, will autonomously acquire and track signals from the first atmospheric probe of Jupiter as well as demodulate, bit-synchronize, and buffer the telemetry data. The receiver has a conventional RF and LF front end but performs multiple functions digitally under firmware control. It will be a self-acquiring receiver that operates under a large frequency uncertainty; it can accommodate different modulation types, bit rates, and other parameter changes via reprogramming. A breadboard receiver and test set demonstrate a preliminary version of the sequential detection process and verify the hypothesis that a fading channel does not reduce the probability of detection.

[Diagnostic imaging of changes of the canine intervertebral disc].

PubMed

Harder, Lisa K

2016-10-12

Intervertebral disc degeneration can cause intervertebral disc herniation. Diagnostic imaging, including radiography, computed tomography and magnetic resonance imaging, is the most important tool in diagnosis. Firstly, an overview of macroscopic and biochemical physiology and pathology of the intervertebral disc will be given. Subsequently, the physics of diagnostic imaging and the appearance of intervertebral disc degeneration and displacement in several imaging methods are described.

108. DETAIL OF DENVER DISC FILTER IN CO91107, SUCTION END. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

108. DETAIL OF DENVER DISC FILTER IN CO-91-107, SUCTION END. NOTE BEARING HOUSING WITH CAST LOGO, SUCTION PIPE GOING OFF TO THE RIGHT, AND FILTER DISC IN BACKGROUND. VACUUM INSIDE DISCS FURTHER DEWATERED CONCENTRATE. AS DISC SLOWLY ROTATED A BAR SCRAPED DRIED CONCENTRATE FROM OUTSIDE OF FILTER CLOTH. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO