Robust feedback zoom tracking for digital video surveillance.

PubMed

Zou, Tengyue; Tang, Xiaoqi; Song, Bao; Wang, Jin; Chen, Jihong

2012-01-01

Zoom tracking is an important function in video surveillance, particularly in traffic management and security monitoring. It involves keeping an object of interest in focus during the zoom operation. Zoom tracking is typically achieved by moving the zoom and focus motors in lenses following the so-called "trace curve", which shows the in-focus motor positions versus the zoom motor positions for a specific object distance. The main task of a zoom tracking approach is to accurately estimate the trace curve for the specified object. Because a proportional integral derivative (PID) controller has historically been considered to be the best controller in the absence of knowledge of the underlying process and its high-quality performance in motor control, in this paper, we propose a novel feedback zoom tracking (FZT) approach based on the geometric trace curve estimation and PID feedback controller. The performance of this approach is compared with existing zoom tracking methods in digital video surveillance. The real-time implementation results obtained on an actual digital video platform indicate that the developed FZT approach not only solves the traditional one-to-many mapping problem without pre-training but also improves the robustness for tracking moving or switching objects which is the key challenge in video surveillance.

Robust Feedback Zoom Tracking for Digital Video Surveillance

PubMed Central

Zou, Tengyue; Tang, Xiaoqi; Song, Bao; Wang, Jin; Chen, Jihong

2012-01-01

Zoom tracking is an important function in video surveillance, particularly in traffic management and security monitoring. It involves keeping an object of interest in focus during the zoom operation. Zoom tracking is typically achieved by moving the zoom and focus motors in lenses following the so-called “trace curve”, which shows the in-focus motor positions versus the zoom motor positions for a specific object distance. The main task of a zoom tracking approach is to accurately estimate the trace curve for the specified object. Because a proportional integral derivative (PID) controller has historically been considered to be the best controller in the absence of knowledge of the underlying process and its high-quality performance in motor control, in this paper, we propose a novel feedback zoom tracking (FZT) approach based on the geometric trace curve estimation and PID feedback controller. The performance of this approach is compared with existing zoom tracking methods in digital video surveillance. The real-time implementation results obtained on an actual digital video platform indicate that the developed FZT approach not only solves the traditional one-to-many mapping problem without pre-training but also improves the robustness for tracking moving or switching objects which is the key challenge in video surveillance. PMID:22969388

Is Magnification Consistent?

ERIC Educational Resources Information Center

Graney, Christopher M.

2010-01-01

Is the phenomenon of magnification by a converging lens inconsistent and therefore unreliable? Can a lens magnify one part of an object but not another? Physics teachers and even students familiar with basic optics would answer "no," yet many answer "yes." Numerous telescope users believe that magnification is not a reliable phenomenon in that it…

Research on surface free energy of electrowetting liquid zoom lens

NASA Astrophysics Data System (ADS)

Zhao, Cunhua; Lu, Gaoqi; Wei, Daling; Hong, Xinhua; Cui, Dongqing; Gao, Changliu

2011-08-01

Zoom imaging systems have the tendencies of miniaturization or complication so the traditional glass / plastic lenses can't meet the needs. Therefore, a new method, liquid lens is put forward which realizes zoom by changing the shape of liquid surface. liquid zoom lenses have many merits such as smaller volume, lighter weight, controlled zoom, faster response, higher transmission, lower energy consumption and so on. Liquid zoom lenses have wide applications in mobile phones, digital cameras and other small imaging system. The electrowetting phenomenon was reviewed firstly and then the influence of the exerted voltage to the contact angle was analysed in electrowetting effect. At last, the surface free energy of cone-type double liquid zoom lens was researched via the energy minimization principle. The research of surface free energy offers important theoretic dependence for designing liquid zoom lens.

Eye-gaze control of the computer interface: Discrimination of zoom intent

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

Goldberg, J.H.; Schryver, J.C.

1993-10-01

An analysis methodology and associated experiment were developed to assess whether definable and repeatable signatures of eye-gaze characteristics are evident, preceding a decision to zoom-in, zoom-out, or not to zoom at a computer interface. This user intent discrimination procedure can have broad application in disability aids and telerobotic control. Eye-gaze was collected from 10 subjects in a controlled experiment, requiring zoom decisions. The eye-gaze data were clustered, then fed into a multiple discriminant analysis (MDA) for optimal definition of heuristics separating the zoom-in, zoom-out, and no-zoom conditions. Confusion matrix analyses showed that a number of variable combinations classified at amore » statistically significant level, but practical significance was more difficult to establish. Composite contour plots demonstrated the regions in parameter space consistently assigned by the MDA to unique zoom conditions. Peak classification occurred at about 1200--1600 msec. Improvements in the methodology to achieve practical real-time zoom control are considered.« less

An Electrically Tunable Zoom System Using Liquid Lenses

PubMed Central

Li, Heng; Cheng, Xuemin; Hao, Qun

2015-01-01

A four-group stabilized zoom system using two liquid lenses and two fixed lens groups is proposed. We describe the design principle, realization, and the testing of a 5.06:1 zoom system. The realized effective focal length (EFL) range is 6.93 mm to 35.06 mm, and the field of view (FOV) range is 8° to 40°. The system can zoom fast when liquid lens 1’s (L1’s) optical power take the value from 0.0087 mm−1 to 0.0192 mm−1 and liquid lens 2’s (L2’s) optical power take the value from 0.0185 mm−1 to −0.01 mm−1. Response time of the realized zoom system was less than 2.5 ms, and the settling time was less than 15 ms.The analysis of elements’ parameters and the measurement of lens performance not only verify the design principle further, but also show the zooming process by the use of two liquid lenses. The system is useful for motion carriers e.g., robot, ground vehicle, and unmanned aerial vehicles considering that it is fast, reliable, and miniature. PMID:26729124

Aberration design of zoom lens systems using thick lens modules.

PubMed

Zhang, Jinkai; Chen, Xiaobo; Xi, Juntong; Wu, Zhuoqi

2014-12-20

A systematic approach for the aberration design of a zoom lens system using a thick lens module is presented. Each component is treated as a thick lens module at the beginning of the design. A thick lens module refers to a thick lens component with a real lens structure, like lens materials, lens curvatures, lens thicknesses, and lens interval distances. All nine third-order aberrations of a thick lens component are considered during the design. The relationship of component aberrations in different zoom positions can be approximated from the aberration shift. After minimizing the aberrations of the zoom lens system, the nine third-order aberrations of every lens component can be determined. Then the thick lens structure of every lens component can be determined after optimization according to their first-order properties and third-order aberration targets. After a third optimization for minimum practical third-order aberrations of a zoom lens system, the aberration design using the thick lens module is complete, which provides a practical zoom lens system with thick lens structures. A double-sided telecentric zoom lens system is designed using the thick lens module in this paper, which shows that this method is practical for zoom lens design.

Design and experimental validation of novel 3D optical scanner with zoom lens unit

NASA Astrophysics Data System (ADS)

Huang, Jyun-Cheng; Liu, Chien-Sheng; Chiang, Pei-Ju; Hsu, Wei-Yan; Liu, Jian-Liang; Huang, Bai-Hao; Lin, Shao-Ru

2017-10-01

Optical scanners play a key role in many three-dimensional (3D) printing and CAD/CAM applications. However, existing optical scanners are generally designed to provide either a wide scanning area or a high 3D reconstruction accuracy from a lens with a fixed focal length. In the former case, the scanning area is increased at the expense of the reconstruction accuracy, while in the latter case, the reconstruction performance is improved at the expense of a more limited scanning range. In other words, existing optical scanners compromise between the scanning area and the reconstruction accuracy. Accordingly, the present study proposes a new scanning system including a zoom-lens unit, which combines both a wide scanning area and a high 3D reconstruction accuracy. In the proposed approach, the object is scanned initially under a suitable low-magnification setting for the object size (setting 1), resulting in a wide scanning area but a poor reconstruction resolution in complicated regions of the object. The complicated regions of the object are then rescanned under a high-magnification setting (setting 2) in order to improve the accuracy of the original reconstruction results. Finally, the models reconstructed after each scanning pass are combined to obtain the final reconstructed 3D shape of the object. The feasibility of the proposed method is demonstrated experimentally using a laboratory-built prototype. It is shown that the scanner has a high reconstruction accuracy over a large scanning area. In other words, the proposed optical scanner has significant potential for 3D engineering applications.

Zooming in on Landing Site

NASA Technical Reports Server (NTRS)

2008-01-01

[figure removed for brevity, see original site] Click on the image for movie of Zooming in on Landing Site

This animation zooms in on the area on Mars where NASA's Phoenix Mars Lander will touchdown on May 25, 2008. The image was taken by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter.

The first shot shows the spacecraft's landing ellipse in green, the area where Phoenix has a high probability of landing. It then zooms in to show the region's arctic terrain. This polar landscape is relatively free of rocks, with only about 1 to 2 rocks 1.5 meters (4.9 feet) or larger in an area about as big as two football fields.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace & Technologies Corp., Boulder, Colo.

Algorithm-Based Motion Magnification for Video Processing in Urological Laparoscopy.

PubMed

Adams, Fabian; Schoelly, Reto; Schlager, Daniel; Schoenthaler, Martin; Schoeb, Dominik S; Wilhelm, Konrad; Hein, Simon; Wetterauer, Ulrich; Miernik, Arkadiusz

2017-06-01

Minimally invasive surgery is in constant further development and has replaced many conventional operative procedures. If vascular structure movement could be detected during these procedures, it could reduce the risk of vascular injury and conversion to open surgery. The recently proposed motion-amplifying algorithm, Eulerian Video Magnification (EVM), has been shown to substantially enhance minimal object changes in digitally recorded video that is barely perceptible to the human eye. We adapted and examined this technology for use in urological laparoscopy. Video sequences of routine urological laparoscopic interventions were recorded and further processed using spatial decomposition and filtering algorithms. The freely available EVM algorithm was investigated for its usability in real-time processing. In addition, a new image processing technology, the CRS iimotion Motion Magnification (CRSMM) algorithm, was specifically adjusted for endoscopic requirements, applied, and validated by our working group. Using EVM, no significant motion enhancement could be detected without severe impairment of the image resolution, motion, and color presentation. The CRSMM algorithm significantly improved image quality in terms of motion enhancement. In particular, the pulsation of vascular structures could be displayed more accurately than in EVM. Motion magnification image processing technology has the potential for clinical importance as a video optimizing modality in endoscopic and laparoscopic surgery. Barely detectable (micro)movements can be visualized using this noninvasive marker-free method. Despite these optimistic results, the technology requires considerable further technical development and clinical tests.

Magnification Bias in Gravitational Arc Statistics

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

Caminha, G. B.; Estrada, J.; Makler, M.

2013-08-29

The statistics of gravitational arcs in galaxy clusters is a powerful probe of cluster structure and may provide complementary cosmological constraints. Despite recent progresses, discrepancies still remain among modelling and observations of arc abundance, specially regarding the redshift distribution of strong lensing clusters. Besides, fast "semi-analytic" methods still have to incorporate the success obtained with simulations. In this paper we discuss the contribution of the magnification in gravitational arc statistics. Although lensing conserves surface brightness, the magnification increases the signal-to-noise ratio of the arcs, enhancing their detectability. We present an approach to include this and other observational effects in semi-analyticmore » calculations for arc statistics. The cross section for arc formation ({\\sigma}) is computed through a semi-analytic method based on the ratio of the eigenvalues of the magnification tensor. Using this approach we obtained the scaling of {\\sigma} with respect to the magnification, and other parameters, allowing for a fast computation of the cross section. We apply this method to evaluate the expected number of arcs per cluster using an elliptical Navarro--Frenk--White matter distribution. Our results show that the magnification has a strong effect on the arc abundance, enhancing the fraction of arcs, moving the peak of the arc fraction to higher redshifts, and softening its decrease at high redshifts. We argue that the effect of magnification should be included in arc statistics modelling and that it could help to reconcile arcs statistics predictions with the observational data.« less

Magnification of digital hip radiographs differs between clinical workplaces.

PubMed

Hornová, Jana; Růžička, Pavel; Hrubina, Maroš; Šťastný, Eduard; Košková, Andrea; Fulín, Petr; Gallo, Jiří; Daniel, Matej

2017-01-01

Preoperative planning for total hip arthroplasty includes templating on anteroposterior radiographs. It is necessary to consider radiographic magnification in order to scale templates accurately. Studies dealing with hip templating report different values of radiographic magnification. It is not clear if the observed difference in magnification between the studies is caused by variability in studied groups, methodology or instrumentation. We hypothesize that there is a difference in magnification between clinical workplaces. Within this study, radiographic magnification was estimated on 337 radiographs of patients after total hip surgery from five orthopaedic departments in the Czech Republic. Magnification was determined for each patient as a ratio between diameter of implanted femoral head measured on radiogram and its true size. One-way ANOVA revealed significant differences in magnification between workplaces (F(4,332) = 132, p≤0.001). These results suggest that radiographic magnification depends on the workplace where it is taken or more precisely on radiographic device. It indicates potential limits in generalizability of results of studies dealing with preoperative planning accuracy to other institutions.

Continuous zoom antenna for mobile visible light communication.

PubMed

Zhang, Xuebin; Tang, Yi; Cui, Lu; Bai, Tingzhu

2015-11-10

In this paper, we design a continuous zoom antenna for mobile visible light communication (VLC). In the design, a right-angle reflecting prism was adopted to fold the space optical path, thus decreasing the antenna thickness. The surface of each lens in the antenna is spherical, and the system cost is relatively low. Simulation results indicated that the designed system achieved the following performance: zoom ratio of 2.44, field of view (FOV) range of 18°-48°, system gain of 16.8, and system size of 18 mm×6  mm. Finally, we established an indoor VLC system model in a room the size of 5  m ×5  m ×3  m and compared the detection results of the zoom antenna and fixed-focus antenna obtained in a multisource communication environment, a mobile VLC environment, and a multiple-input multiple-output communication environment. The simulation results indicated that the continuous zoom antenna could realize large FOV and high gain. Moreover, the system showed improved stability, mobility, and environmental applicability.

Designing Computer-Based Learning Contents: Influence of Digital Zoom on Attention

ERIC Educational Resources Information Center

Glaser, Manuela; Lengyel, Dominik; Toulouse, Catherine; Schwan, Stephan

2017-01-01

In the present study, we investigated the role of digital zoom as a tool for directing attention while looking at visual learning material. In particular, we analyzed whether minimal digital zoom functions similarly to a rhetorical device by cueing mental zooming of attention accordingly. Participants were presented either static film clips, film…

Design, fabrication, and testing of duralumin zoom mirror with variable thickness

NASA Astrophysics Data System (ADS)

Hui, Zhao; Xie, Xiaopeng; Xu, Liang; Ding, Jiaoteng; Shen, Le; Liu, Meiying; Gong, Jie

2016-10-01

Zoom mirror is a kind of active optical component that can change its curvature radius dynamically. Normally, zoom mirror is used to correct the defocus and spherical aberration caused by thermal lens effect to improve the beam quality of high power solid-state laser since that component was invented. Recently, the probable application of zoom mirror in realizing non-moving element optical zoom imaging in visible band has been paid much attention. With the help of optical leveraging effect, the slightly changed local optical power caused by curvature variation of zoom mirror could be amplified to generate a great alteration of system focal length without moving elements involved in, but in this application the shorter working wavelength and higher surface figure accuracy requirement make the design and fabrication of such a zoom mirror more difficult. Therefore, the key to realize non-moving element optical zoom imaging in visible band lies in zoom mirror which could provide a large enough saggitus variation while still maintaining a high enough surface figure. Although the annular force based actuation could deform a super-thin mirror having a constant thickness to generate curvature variation, it is quite difficult to maintain a high enough surface figure accuracy and this phenomenon becomes even worse when the diameter and the radius-thickness ratio become bigger. In this manuscript, by combing the pressurization based actuation with a variable thickness mirror design, the purpose of obtaining large saggitus variation and maintaining quite good surface figure accuracy at the same time could be achieved. A prototype zoom mirror with diameter of 120mm and central thickness of 8mm is designed, fabricated and tested. Experimental results demonstrate that the zoom mirror having an initial surface figure accuracy superior to 1/50λ could provide at least 21um saggitus variation and after finishing the curvature variation its surface figure accuracy could still be

Graded zooming

DOEpatents

Coffland, Douglas R.

2006-04-25

A system for increasing the resolution in the far field resolution of video or still frame images, while maintaining full coverage in the near field. The system includes a camera connected to a computer. The computer applies a specific zooming scale factor to each of line of pixels and continuously increases the scale factor of the line of pixels from the bottom to the top to capture the scene in the near field, yet maintain resolution in the scene in the far field.

Introduction to magnification in endodontics.

PubMed

Arens, Donald E

2003-01-01

Dentistry has recently recognized the practicality and benefits of treating damaged and diseased oral tissues under high magnification levels. Initially, enhanced vision was more-or-less restricted to the use of prescription bifocals, awkward magnifying loops, and heavy cumbersome telephoto glasses; the microscope drew little interest and was quickly viewed as another useless and expensive dental gadget. However, owing to the very nature and demands of the therapy, endodontists were quick to accept and adopt this technology, and the manufacturers were quick to adapt and market their surgical microscopes to the endodontic office. Since acceptance leads to progression, we are currently witnessing manufacturers adapting the microscopic and other magnifying lenses to other areas of dentistry. However, choosing and purchasing a microscope involves a great number of issues, including the adequacy of one's present vision, the type of practice conducted, the demands one places on the quality of his or her dentistry, and the amount of time and expense one wishes to devote to becoming competent in using magnification. In addition, one must become familiar with what the different levels of magnification offer, what different depths and widths of field meet their normal practice needs, the amount of space required for the equipment, and whether the investment is cost effective. This article details all of the benefits as well as the difficulties encountered when embarking on a magnification journey. The art of dentistry is based on precision. The human naked eye is capable of distinguishing fine detail, but it is no match for what can be accomplished when an image is sharpened and enlarged. The microscope and other forms of magnification fill that need, especially for accomplishing endodontic procedures.

A reflection polarizations zoom metasurfaces

NASA Astrophysics Data System (ADS)

Yang, Fulong; Wang, Xiaoyan

2017-02-01

Based on generalized Snell's law, we propose a dual-polarity zoom metasurfaces operating electromagnetic wave in the reflection geometry. The metasurfaces is constructed by two identical ultrathin metal-backed dielectric slabs with metallic Jerusalem cross patterns on the other sides to form a triangular region. The normally incident waves are totally reflected, but the reflection phases of both x- and y-polarized waves are controlled independently. According to the classical theory of optical imaging, the reflection electromagnetic wave phases were obtained in the different polarizations and focus. Each subwavelength units size were determined with the reflection coefficient of the basic unit, the polarizations zoom metasurfaces was designed in the way. The full-wave simulations are in good agreement with theoretical analysis in microwave lengths.

Optical zoom system realized by lateral shift of Alvarez freeform lenses

NASA Astrophysics Data System (ADS)

Hou, Changlun; Xin, Qing; Zang, Yue

2018-04-01

We present and characterize an optical zoom system with lateral movement of an Alvarez freeform lens for imaging. Mathematical analysis for determining the required freeform surfaces is presented, and optical simulations are performed to confirm and refine the expected zooming behavior. A 3 × optical zoom system that was equivalent to a photographic objective lens with focal length ranging from 34.5 to 103.5 mm and field of view ranging from 60 deg to 22.4 deg is developed by using two pairs of Alvarez lenses and conventional aspheric lenses. The optical performances of the Alvarez zoom system are demonstrated experimentally.

Design of a zoom lens without motorized optical elements

NASA Astrophysics Data System (ADS)

Peng, Runling; Chen, Jiabi; Zhu, Cheng; Zhuang, Songlin

2007-05-01

A novel design of a zoom lens system without motorized movements is proposed. The lens system consists of a fixed lens and two double-liquid variable-focus lenses. The liquid lenses, made out of two immiscible liquids, are based on the principle of electrowetting: an effect controlling the wetting properties of a liquid on a solid by modifying the applied voltage at the solid-liquid interface. The structure and principle of the lens system are introduced in this paper. Detailed calculations and simulation examples are presented to show that this zoom lens system appears viable as the next-generation zoom lens.

Design of a zoom lens without motorized optical elements.

PubMed

Peng, Runling; Chen, Jiabi; Zhu, Cheng; Zhuang, Songlin

2007-05-28

A novel design of a zoom lens system without motorized movements is proposed. The lens system consists of a fixed lens and two double-liquid variable-focus lenses. The liquid lenses, made out of two immiscible liquids, are based on the principle of electrowetting: an effect controlling the wetting properties of a liquid on a solid by modifying the applied voltage at the solid-liquid interface. The structure and principle of the lens system are introduced in this paper. Detailed calculations and simulation examples are presented to show that this zoom lens system appears viable as the next-generation zoom lens.

Probability of lensing magnification by cosmologically distributed galaxies

NASA Technical Reports Server (NTRS)

Pei, Yichuan C.

1993-01-01

We present the analytical formulae for computing the magnification probability caused by cosmologically distributed galaxies. The galaxies are assumed to be singular, truncated-isothermal spheres without both evolution and clustering in redshift. We find that, for a fixed total mass, extended galaxies produce a broader shape in the magnification probability distribution and hence are less efficient as gravitational lenses than compact galaxies. The high-magnification tail caused by large galaxies is well approximated by an A exp -3 form, while the tail by small galaxies is slightly shallower. The mean magnification as a function of redshift is, however, found to be independent of the size of the lensing galaxies. In terms of the flux conservation, our formulae for the isothermal galaxy model predict a mean magnification to within a few percent with the Dyer-Roeder model of a clumpy universe.

The Zoom Lens: A Case Study in Geometrical Optics.

ERIC Educational Resources Information Center

Cheville, Alan; Scepanovic, Misa

2002-01-01

Introduces a case study on a motion picture company considering the purchase of a newly developed zoom lens in which students act as the engineers designing the zoom lens based on the criteria of company's specifications. Focuses on geometrical optics. Includes teaching notes and classroom management strategies. (YDS)

Electronic magnification for astronomical camera tubes

NASA Technical Reports Server (NTRS)

Vine, J.; Hansen, J. R.; Pietrzyk, J. P.

1974-01-01

Definitions, test schemes, and analyses used to provide variable magnification in the image section of the television sensor for large space telescopes are outlined. Experimental results show a definite form of magnetic field distribution is necessary to achieve magnification in the range 3X to 4X. Coil systems to establish the required field shapes were built, and both image intensifiers and camera tubes were operated at high magnification. The experiments confirm that such operation is practical and can provide satisfactory image quality. The main problem with such a system was identified as heating of the photocathode due to concentration of coil power dissipation in that vicinity. Suggestions for overcoming this disadvantage are included.

Design study for a 16x zoom lens system for visible surveillance camera

NASA Astrophysics Data System (ADS)

Vella, Anthony; Li, Heng; Zhao, Yang; Trumper, Isaac; Gandara-Montano, Gustavo A.; Xu, Di; Nikolov, Daniel K.; Chen, Changchen; Brown, Nicolas S.; Guevara-Torres, Andres; Jung, Hae Won; Reimers, Jacob; Bentley, Julie

2015-09-01

*avella@ur.rochester.edu Design study for a 16x zoom lens system for visible surveillance camera Anthony Vella*, Heng Li, Yang Zhao, Isaac Trumper, Gustavo A. Gandara-Montano, Di Xu, Daniel K. Nikolov, Changchen Chen, Nicolas S. Brown, Andres Guevara-Torres, Hae Won Jung, Jacob Reimers, Julie Bentley The Institute of Optics, University of Rochester, Wilmot Building, 275 Hutchison Rd, Rochester, NY, USA 14627-0186 ABSTRACT High zoom ratio zoom lenses have extensive applications in broadcasting, cinema, and surveillance. Here, we present a design study on a 16x zoom lens with 4 groups (including two internal moving groups), designed for, but not limited to, a visible spectrum surveillance camera. Fifteen different solutions were discovered with nearly diffraction limited performance, using PNPX or PNNP design forms with the stop located in either the third or fourth group. Some interesting patterns and trends in the summarized results include the following: (a) in designs with such a large zoom ratio, the potential of locating the aperture stop in the front half of the system is limited, with ray height variations through zoom necessitating a very large lens diameter; (b) in many cases, the lens zoom motion has significant freedom to vary due to near zero total power in the middle two groups; and (c) we discuss the trade-offs between zoom configuration, stop location, packaging factors, and zoom group aberration sensitivity.

Who's Zooming Whom? Attunement to Animation in the Interface.

ERIC Educational Resources Information Center

Chui, Michael; Dillon, Andrew

1997-01-01

Two controlled experiments examined whether the animated zooming effect accompanying the opening or closing of a folder in the Apple Macintosh graphical user interface aids in the user's perception of which window corresponds to which folder. Results suggest users may become attuned to the informational content of the zooming effect with…

Zooming in on Science

ERIC Educational Resources Information Center

Thorn, Courtney; Rye, James; Walls, Holly

2017-01-01

Photography is a creative art that continues to advance through technological innovations. Smart phones have made photography a nearly daily occurance, and people have become quite accustomed to zooming in and taking photos. This article explains how elementary teachers can harness a much "bigger" technology application--GigaPan--to help…

Bifocal liquid lens zoom objective for mobile phone applications

NASA Astrophysics Data System (ADS)

Wippermann, F. C.; Schreiber, P.; Bräuer, A.; Craen, P.

2007-02-01

Miniaturized camera systems are an integral part of today's mobile phones which recently possess auto focus functionality. Commercially available solutions without moving parts have been developed using the electrowetting technology. Here, the contact angle of a drop of a conductive or polar liquid placed on an insulating substrate can be influenced by an electric field. Besides the compensation of the axial image shift due to different object distances, mobile phones with zoom functionality are desired as a next evolutionary step. In classical mechanically compensated zoom lenses two independently driven actuators combined with precision guides are needed leading to a delicate, space consuming and expansive opto-mechanical setup. Liquid lens technology based on the electrowetting effect gives the opportunity to built adaptive lenses without moving parts thus simplifying the mechanical setup. However, with the recent commercially available liquid lens products a completely motionless and continuously adaptive zoom system with market relevant optical performance is not feasible. This is due to the limited change in optical power the liquid lenses can provide and the dispersion of the used materials. As an intermediate step towards a continuously adjustable and motionless zoom lens we propose a bifocal system sufficient for toggling between two effective focal lengths without any moving parts. The system has its mechanical counterpart in a bifocal zoom lens where only one lens group has to be moved. In a liquid lens bifocal zoom two groups of adaptable liquid lenses are required for adjusting the effective focal length and keeping the image location constant. In order to overcome the difficulties in achromatizing the lens we propose a sequential image acquisition algorithm. Here, the full color image is obtained from a sequence of monochrome images (red, green, blue) leading to a simplified optical setup.

Development of variable-magnification X-ray Bragg optics.

PubMed

Hirano, Keiichi; Yamashita, Yoshiki; Takahashi, Yumiko; Sugiyama, Hiroshi

2015-07-01

A novel X-ray Bragg optics is proposed for variable-magnification of an X-ray beam. This X-ray Bragg optics is composed of two magnifiers in a crossed arrangement, and the magnification factor, M, is controlled through the azimuth angle of each magnifier. The basic properties of the X-ray optics such as the magnification factor, image transformation matrix and intrinsic acceptance angle are described based on the dynamical theory of X-ray diffraction. The feasibility of the variable-magnification X-ray Bragg optics was verified at the vertical-wiggler beamline BL-14B of the Photon Factory. For X-ray Bragg magnifiers, Si(220) crystals with an asymmetric angle of 14° were used. The magnification factor was calculated to be tunable between 0.1 and 10.0 at a wavelength of 0.112 nm. At various magnification factors (M ≥ 1.0), X-ray images of a nylon mesh were observed with an air-cooled X-ray CCD camera. Image deformation caused by the optics could be corrected by using a 2 × 2 transformation matrix and bilinear interpolation method. Not only absorption-contrast but also edge-contrast due to Fresnel diffraction was observed in the magnified images.

Zooming in on Landing Site

NASA Image and Video Library

2008-05-24

This animation zooms in on the area on Mars where NASA Phoenix Mars Lander will touchdown on May 25, 2008. The image was taken by the High Resolution Imaging Science Experiment HiRISE camera on NASA Mars Reconnaissance Orbiter.

Thales Angenieux: 42 years of cine 35 mm zoom leadership

NASA Astrophysics Data System (ADS)

Debize, Jacques

2004-02-01

Since the early years of zoom optics, Angenieux has been involved in cine 8 mm, 16 mm and 35 mm. Among more than twenty different zoom lenses, four of them have been milestones in this field, technical progresses being sanctified by two Oscars in 1964 and 1990. From 1960 to 2002 Angenieux has created first the 4 x 35 LA2, the first four times mechanically compensated zoom lens for cine 35 mm in the world, secondary the 10 x 25 T2, the first ten times mechanically compensated zoom lens for cine 35 mm in the world, then the 10 x 25 HR, the top level of quality for its category and finally the 12 x 24 Optimo with all characteristics and performances greatly increased. This leadership has been reached thanks to computers and in-house softwares but also thanks to new manufacturing processes.

Motion magnification using the Hermite transform

NASA Astrophysics Data System (ADS)

Brieva, Jorge; Moya-Albor, Ernesto; Gomez-Coronel, Sandra L.; Escalante-Ramírez, Boris; Ponce, Hiram; Mora Esquivel, Juan I.

2015-12-01

We present an Eulerian motion magnification technique with a spatial decomposition based on the Hermite Transform (HT). We compare our results to the approach presented in.1 We test our method in one sequence of the breathing of a newborn baby and on an MRI left ventricle sequence. Methods are compared using quantitative and qualitative metrics after the application of the motion magnification algorithm.

Dynamic Magnification Factor in a Box-Shape Steel Girder

NASA Astrophysics Data System (ADS)

Rahbar-Ranji, A.

2014-01-01

The dynamic effect of moving loads on structures is treated as a dynamic magnification factor when resonant is not imminent. Studies have shown that the calculated magnification factors from field measurements could be higher than the values specified in design codes. It is the main aim of present paper to investigate the applicability and accuracy of a rule-based expression for calculation of dynamic magnification factor for lifting appliances used in marine industry. A steel box shape girder of a crane is considered and transient dynamic analysis using computer code ANSYS is implemented. Dynamic magnification factor is calculated for different loading conditions and compared with rule-based equation. The effects of lifting speeds, acceleration, damping ratio and position of cargo are examined. It is found that rule-based expression underestimate dynamic magnification factor.

Mediated-reality magnification for macular degeneration rehabilitation

NASA Astrophysics Data System (ADS)

Martin-Gonzalez, Anabel; Kotliar, Konstantin; Rios-Martinez, Jorge; Lanzl, Ines; Navab, Nassir

2014-10-01

Age-related macular degeneration (AMD) is a gradually progressive eye condition, which is one of the leading causes of blindness and low vision in the Western world. Prevailing optical visual aids compensate part of the lost visual function, but omitting helpful complementary information. This paper proposes an efficient magnification technique, which can be implemented on a head-mounted display, for improving vision of patients with AMD, by preserving global information of the scene. Performance of the magnification approach is evaluated by simulating central vision loss in normally sighted subjects. Visual perception was measured as a function of text reading speed and map route following speed. Statistical analysis of experimental results suggests that our magnification method improves reading speed 1.2 times and spatial orientation to find routes on a map 1.5 times compared to a conventional magnification approach, being capable to enhance peripheral vision of AMD subjects along with their life quality.

Structural design of off-axis aspheric surface reflective zoom optical system

NASA Astrophysics Data System (ADS)

Zhang, Ke; Chang, Jun; Song, Haiping; Niu, Yajun

2018-01-01

Designed an off-axis aspheric reflective zoom optical system, and produced a prototype. The system consists of three aspheric reflective lens, the zoom range is 30mm { 90mm. This system gave up the traditional structure of zoom cam, the lens moved using linear guide rail driven by motor, the positioning precision of which was 0.01mm. And introduced the design of support frames of each lens. The practice tests verified the rationality of the prototype structure design.

Flat liquid crystal diffractive lenses with variable focus and magnification

NASA Astrophysics Data System (ADS)

Valley, Pouria

Non-mechanical variable lenses are important for creating compact imaging devices. Various methods employing dielectrically actuated lenses, membrane lenses, and liquid crystal lenses were previously proposed [1-4]. In This dissertation the design, fabrication, and characterization of innovative flat tunable-focus liquid crystal diffractive lenses (LCDL) are presented. LCDL employ binary Fresnel zone electrodes fabricated on Indium-Tin-Oxide using conventional micro-photolithography. The light phase can be adjusted by varying the effective refractive index of a nematic liquid crystal sandwiched between the electrodes and a reference substrate. Using a proper voltage distribution across various electrodes the focal length can be changed between several discrete values. Electrodes are shunted such that the correct phase retardation step sequence is achieved. If the number of 2pi zone boundaries is increased by a factor of m the focal length is changed from f to f/m based on the digitized Fresnel zone equation: f = rm2/2mlambda, where r m is mth zone radius, and lambda is the wavelength. The chromatic aberration of the diffractive lens is addressed and corrected by adding a variable fluidic lens. These LCDL operate at very low voltage levels (+/-2.5V ac input), exhibit fast switching times (20-150 ms), can have large apertures (>10 mm), and small form factor, and are robust and insensitive to vibrations, gravity, and capillary effects that limit membrane and dielectrically actuated lenses. Several tests were performed on the LCDL including diffraction efficiency measurement, switching dynamics, and hybrid imaging with a refractive lens. Negative focal lengths are achieved by adjusting the voltages across electrodes. Using these lenses in combination, magnification can be changed and zoom lenses can be formed. These characteristics make LCDL a good candidate for a variety of applications including auto-focus and zoom lenses in compact imaging devices such as camera

Zoomed EPI-DWI of the pancreas using two-dimensional spatially-selective radiofrequency excitation pulses.

PubMed

Riffel, Philipp; Michaely, Henrik J; Morelli, John N; Pfeuffer, Josef; Attenberger, Ulrike I; Schoenberg, Stefan O; Haneder, Stefan

2014-01-01

Implementation of DWI in the abdomen is challenging due to artifacts, particularly those arising from differences in tissue susceptibility. Two-dimensional, spatially-selective radiofrequency (RF) excitation pulses for single-shot echo-planar imaging (EPI) combined with a reduction in the FOV in the phase-encoding direction (i.e. zooming) leads to a decreased number of k-space acquisition lines, significantly shortening the EPI echo train and potentially susceptibility artifacts. To assess the feasibility and image quality of a zoomed diffusion-weighted EPI (z-EPI) sequence in MR imaging of the pancreas. The approach is compared to conventional single-shot EPI (c-EPI). 23 patients who had undergone an MRI study of the abdomen were included in this retrospective study. Examinations were performed on a 3T whole-body MR system (Magnetom Skyra, Siemens) equipped with a two-channel fully dynamic parallel transmit array (TimTX TrueShape, Siemens). The acquired sequences consisted of a conventional EPI DWI of the abdomen and a zoomed EPI DWI of the pancreas. For z-EPI, the standard sinc excitation was replaced with a two-dimensional spatially-selective RF pulse using an echo-planar transmit trajectory. Images were evaluated with regard to image blur, respiratory motion artifacts, diagnostic confidence, delineation of the pancreas, and overall scan preference. Additionally ADC values of the pancreatic head, body, and tail were calculated and compared between sequences. The pancreas was better delineated in every case (23/23) with z-EPI versus c-EPI. In every case (23/23), both readers preferred z-EPI overall to c-EPI. With z-EPI there was statistically significantly less image blur (p<0.0001) and respiratory motion artifact compared to c-EPI (p<0.0001). Diagnostic confidence was statistically significantly better with z-EPI (p<0.0001). No statistically significant differences in calculated ADC values were observed between the two sequences. Zoomed diffusion-weighted EPI

Vision though afocal instruments: generalized magnification and eye-instrument interaction

NASA Astrophysics Data System (ADS)

Harris, William F.; Evans, Tanya

2018-04-01

In Gaussian optics all observers experience the same magnification, the instrument's angular magnification, when viewing distant objects though a telescope or other afocal instruments. However, analysis in linear optics shows that this is not necessarily so in the presence of astigmatism. Because astigmatism may distort and rotate images it is appropriate to work with generalized angular magnification represented by a 2 × 2 matrix. An expression is derived for the generalized magnification for an arbitrary eye looking through an arbitrary afocal instrument. With afocal instruments containing astigmatic refracting elements not all eyes experience the same generalized magnification; there is interaction between eye and instrument. Eye-instrument interaction may change as the instrument is rotated about its longitudinal axis, there being no interaction in particular orientations. A simple numerical example is given. For sake of completeness, expressions for generalized magnification are also presented in the case of instruments that are not afocal and objects that are not distant.

BIASES IN PHYSICAL PARAMETER ESTIMATES THROUGH DIFFERENTIAL LENSING MAGNIFICATION

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

Er Xinzhong; Ge Junqiang; Mao Shude, E-mail: xer@nao.cas.cn

2013-06-20

We study the lensing magnification effect on background galaxies. Differential magnification due to different magnifications of different source regions of a galaxy will change the lensed composite spectra. The derived properties of the background galaxies are therefore biased. For simplicity, we model galaxies as a superposition of an axis-symmetric bulge and a face-on disk in order to study the differential magnification effect on the composite spectra. We find that some properties derived from the spectra (e.g., velocity dispersion, star formation rate, and metallicity) are modified. Depending on the relative positions of the source and the lens, the inferred results canmore » be either over- or underestimates of the true values. In general, for an extended source at strong lensing regions with high magnifications, the inferred physical parameters (e.g., metallicity) can be strongly biased. Therefore, detailed lens modeling is necessary to obtain the true properties of the lensed galaxies.« less

Design of large zoom for visible and infrared optical system in hemisphere space

NASA Astrophysics Data System (ADS)

Xing, Yang-guang; Li, Lin; Zhang, Juan

2018-01-01

In the field of space optical, the application of advanced optical instruments for related target detection and identification has become an advanced technology in modern optics. In order to complete the task of search in wide field of view and detailed investigation in small field of view, it is inevitable to use the structure of the zoom system to achieve a better observation for important targets. The innovation of this paper lies in using the zoom optical system in space detection, which achieve firstly military needs of searched target in the large field of view and recognized target in the small field of view. At the same time, this paper also completes firstly the design of variable focus optical detection system in the range of hemisphere space, the zoom optical system is working in the range of visible and infrared wavelengths, the perspective angle reaches 360 ° and the zoom ratio of the visible system is up to 15. The visible system has a zoom range of 60-900 mm, a detection band of 0.48-0.70μm, and a F-number of 2.0 to 5.0. The infrared system has a zoom range of 150 900mm, a detection band of 8-12μm, and a F-number of 1.2 to 3.0. The MTF of the visible zoom system is above 0.4 at spatial frequency of 45 lp / mm, and the infrared zoom system is above 0.4 at spatial frequency of 11 lp / mm. The design results show that the system has a good image quality.

Electronic magnification and perceived contrast of video

PubMed Central

Haun, Andrew; Woods, Russell L; Peli, Eli

2012-01-01

Electronic magnification of an image results in a decrease in its perceived contrast. The decrease in perceived contrast could be due to a perceived blur or to limited sampling of the range of contrasts in the original image. We measured the effect on perceived contrast of magnification in two contexts: either a small video was enlarged to fill a larger area, or a portion of a larger video was enlarged to fill the same area as the original. Subjects attenuated the source video contrast to match the perceived contrast of the magnified videos, with the effect increasing with magnification and decreasing with viewing distance. These effects are consistent with expectations based on both the contrast statistics of natural images and the contrast sensitivity of the human visual system. We demonstrate that local regions within videos usually have lower physical contrast than the whole, and that this difference accounts for a minor part of the perceived differences. Instead, visibility of ‘missing content’ (blur) in a video is misinterpreted as a decrease in contrast. We detail how the effects of magnification on perceived contrast can be measured while avoiding confounding factors. PMID:23483111

A Cost-Effective Fluorescence Mini-Microscope with Adjustable Magnifications for Biomedical Applications

PubMed Central

Zhang, Yu Shrike; Ribas, João; Nadhman, Akhtar; Aleman, Julio; Selimović, Šeila; Lesher-Perez, Sasha Cai; Wang, Ting; Manoharan, Vijayan; Shin, Su-Ryon; Damilano, Alessia; Annabi, Nasim; Dokmeci, Mehmet Remzi; Takayama, Shuichi; Khademhosseini, Ali

2015-01-01

We have designed and fabricated a miniature microscope from off-the-shelf components and webcam, with built-in fluorescence capability for biomedical applications. The mini-microscope was able to detect both biochemical parameters such as cell/tissue viability (e.g. Live/Dead assay), and biophysical properties of the microenvironment such as oxygen levels in microfabricated tissues based on an oxygen-sensitive fluorescent dye. This mini-microscope has adjustable magnifications from 8-60X, achieves a resolution as high as <2 μm, and possesses a long working distance of 4.5 mm (at a magnification of 8X). The mini-microscope was able to chronologically monitor cell migration and analyze beating of microfluidic liver and cardiac bioreactors in real time, respectively. The mini-microscope system is cheap, and its modularity allows convenient integration with a wide variety of pre-existing platforms including but not limited to, cell culture plates, microfluidic devices, and organs-on-a-chip systems. Therefore, we envision its widespread applications in cell biology, tissue engineering, biosensing, microfluidics, and organs-on-chips, which can potentially replace conventional bench-top microscopy where long-term in situ and large-scale imaging/analysis is required. PMID:26282117

Teaching Shakespeare in the Digital Age: The eZoomBook Approach

ERIC Educational Resources Information Center

Evain, Christine; De Marco, Chris

2016-01-01

What collaborative process can teachers offer in order to stimulate their students' reading of and writing on Shakespeare's plays? How can new technologies contribute to facilitating the classroom experience? The eZoomBook (eZB) template was designed for teachers to create and share multi-level digital books called "eZoomBooks" that…

Magnifying image intensifier

NASA Technical Reports Server (NTRS)

Vine, J.

1977-01-01

Coil assembly for zoom operation produces axial magnetic flux density that decreases in strength from photocathode to target. This results in magnification factor greater than unity. To extend magnification range, field is reversed in direction between object and image planes.

Optical design of laser zoom projective lens with variable total track

NASA Astrophysics Data System (ADS)

He, Yulan; Xiao, Xiangguo; Lu, Feng; Li, Yuan; Han, Kunye; Wang, Nanxi; Qiang, Hua

2017-02-01

In order to project the laser command information to the proper distance , so a laser zoom projective lens with variable total track optical system is designed in the carrier-based aircraft landing system. By choosing the zoom structure, designing of initial structure with PW solution, correcting and balancing the aberration, a large variable total track with 35 × zoom is carried out. The size of image is invariable that is φ25m, the distance of projective image is variable from 100m to 3500m. Optical reverse design, the spot is less than 8μm, the MTF is near the diffraction limitation, the value of MTF is bigger than 0.4 at 50lp/mm.

ZOOM Lite: next-generation sequencing data mapping and visualization software

PubMed Central

Zhang, Zefeng; Lin, Hao; Ma, Bin

2010-01-01

High-throughput next-generation sequencing technologies pose increasing demands on the efficiency, accuracy and usability of data analysis software. In this article, we present ZOOM Lite, a software for efficient reads mapping and result visualization. With a kernel capable of mapping tens of millions of Illumina or AB SOLiD sequencing reads efficiently and accurately, and an intuitive graphical user interface, ZOOM Lite integrates reads mapping and result visualization into a easy to use pipeline on desktop PC. The software handles both single-end and paired-end reads, and can output both the unique mapping result or the top N mapping results for each read. Additionally, the software takes a variety of input file formats and outputs to several commonly used result formats. The software is freely available at http://bioinfor.com/zoom/lite/. PMID:20530531

ZebraZoom: an automated program for high-throughput behavioral analysis and categorization

PubMed Central

Mirat, Olivier; Sternberg, Jenna R.; Severi, Kristen E.; Wyart, Claire

2013-01-01

The zebrafish larva stands out as an emergent model organism for translational studies involving gene or drug screening thanks to its size, genetics, and permeability. At the larval stage, locomotion occurs in short episodes punctuated by periods of rest. Although phenotyping behavior is a key component of large-scale screens, it has not yet been automated in this model system. We developed ZebraZoom, a program to automatically track larvae and identify maneuvers for many animals performing discrete movements. Our program detects each episodic movement and extracts large-scale statistics on motor patterns to produce a quantification of the locomotor repertoire. We used ZebraZoom to identify motor defects induced by a glycinergic receptor antagonist. The analysis of the blind mutant atoh7 revealed small locomotor defects associated with the mutation. Using multiclass supervised machine learning, ZebraZoom categorized all episodes of movement for each larva into one of three possible maneuvers: slow forward swim, routine turn, and escape. ZebraZoom reached 91% accuracy for categorization of stereotypical maneuvers that four independent experimenters unanimously identified. For all maneuvers in the data set, ZebraZoom agreed with four experimenters in 73.2–82.5% of cases. We modeled the series of maneuvers performed by larvae as Markov chains and observed that larvae often repeated the same maneuvers within a group. When analyzing subsequent maneuvers performed by different larvae, we found that larva–larva interactions occurred as series of escapes. Overall, ZebraZoom reached the level of precision found in manual analysis but accomplished tasks in a high-throughput format necessary for large screens. PMID:23781175

Optimization design of periscope type 3X zoom lens design for a five megapixel cellphone camera

NASA Astrophysics Data System (ADS)

Sun, Wen-Shing; Tien, Chuen-Lin; Pan, Jui-Wen; Chao, Yu-Hao; Chu, Pu-Yi

2016-11-01

This paper presents a periscope type 3X zoom lenses design for a five megapixel cellphone camera. The configuration of optical system uses the right angle prism in front of the zoom lenses to change the optical path rotated by a 90° angle resulting in the zoom lenses length of 6 mm. The zoom lenses can be embedded in mobile phone with a thickness of 6 mm. The zoom lenses have three groups with six elements. The half field of view is varied from 30° to 10.89°, the effective focal length is adjusted from 3.142 mm to 9.426 mm, and the F-number is changed from 2.8 to 5.13.

Intuitive tactile zooming for graphics accessed by individuals who are blind and visually impaired.

PubMed

Rastogi, Ravi; Pawluk, T V Dianne; Ketchum, Jessica

2013-07-01

One possibility of providing access to visual graphics for those who are visually impaired is to present them tactually: unfortunately, details easily available to vision need to be magnified to be accessible through touch. For this, we propose an "intuitive" zooming algorithm to solve potential problems with directly applying visual zooming techniques to haptic displays that sense the current location of a user on a virtual diagram with a position sensor and, then, provide the appropriate local information either through force or tactile feedback. Our technique works by determining and then traversing the levels of an object tree hierarchy of a diagram. In this manner, the zoom steps adjust to the content to be viewed, avoid clipping and do not zoom when no object is present. The algorithm was tested using a small, "mouse-like" display with tactile feedback on pictures representing houses in a community and boats on a lake. We asked the users to answer questions related to details in the pictures. Comparing our technique to linear and logarithmic step zooming, we found a significant increase in the correctness of the responses (odds ratios of 2.64:1 and 2.31:1, respectively) and usability (differences of 36% and 19%, respectively) using our "intuitive" zooming technique.

Optical zoom lens module using MEMS deformable mirrors for portable device

NASA Astrophysics Data System (ADS)

Lu, Jia-Shiun; Su, Guo-Dung J.

2012-10-01

The thickness of the smart phones in today's market is usually below than 10 mm, and with the shrinking of the phone volume, the difficulty of its production of the camera lens has been increasing. Therefore, how to give the imaging device more functionality in the smaller space is one of the interesting research topics for today's mobile phone companies. In this paper, we proposed a thin optical zoom system which is combined of micro-electromechanical components and reflective optical architecture. By the adopting of the MEMS deformable mirrors, we can change their radius of curvature to reach the optical zoom in and zoom out. And because we used the all-reflective architecture, so this system has eliminated the considerable chromatic aberrations in the absence of lenses. In our system, the thickness of the zoom system is about 11 mm. The smallest EFL (effective focal length) is 4.61 mm at a diagonal field angle of 52° and f/# of 5.24. The longest EFL of the module is 9.22 mm at a diagonal field angle of 27.4 with f/# of 5.03.°

Ultrathin zoom lens system based on liquid lenses

NASA Astrophysics Data System (ADS)

Li, Lei; Liu, Chao; Wang, Qiong-Hua

2015-07-01

In this paper, we propose an ultrathin zoom lens system based on liquid lenses. The proposed system consists of an annular folded lens and three electrowetting liquid lenses. The annular folded lens has several concentric surfaces. The annular folded lens is used to get the main power and correct aberrations. The three liquid lenses are used to change the focal length and correct aberration. An analysis of the proposed system is presented along with the design, fabrication, and testing of a prototype. All the elements in the proposed system are very thin, so the system is an ultrathin zoom lens system, which has potential application as lightweight, thin, high-quality imagers for aerospace, consumer, and military applications.

Weak lensing magnification of SpARCS galaxy clusters

NASA Astrophysics Data System (ADS)

Tudorica, A.; Hildebrandt, H.; Tewes, M.; Hoekstra, H.; Morrison, C. B.; Muzzin, A.; Wilson, G.; Yee, H. K. C.; Lidman, C.; Hicks, A.; Nantais, J.; Erben, T.; van der Burg, R. F. J.; Demarco, R.

2017-12-01

Context. Measuring and calibrating relations between cluster observables is critical for resource-limited studies. The mass-richness relation of clusters offers an observationally inexpensive way of estimating masses. Its calibration is essential for cluster and cosmological studies, especially for high-redshift clusters. Weak gravitational lensing magnification is a promising and complementary method to shear studies, that can be applied at higher redshifts. Aims: We aim to employ the weak lensing magnification method to calibrate the mass-richness relation up to a redshift of 1.4. We used the Spitzer Adaptation of the Red-Sequence Cluster Survey (SpARCS) galaxy cluster candidates (0.2 < z < 1.4) and optical data from the Canada France Hawaii Telescope (CFHT) to test whether magnification can be effectively used to constrain the mass of high-redshift clusters. Methods: Lyman-break galaxies (LBGs) selected using the u-band dropout technique and their colours were used as a background sample of sources. LBG positions were cross-correlated with the centres of the sample of SpARCS clusters to estimate the magnification signal, which was optimally-weighted using an externally-calibrated LBG luminosity function. The signal was measured for cluster sub-samples, binned in both redshift and richness. Results: We measured the cross-correlation between the positions of galaxy cluster candidates and LBGs and detected a weak lensing magnification signal for all bins at a detection significance of 2.6-5.5σ. In particular, the significance of the measurement for clusters with z> 1.0 is 4.1σ; for the entire cluster sample we obtained an average M200 of 1.28 -0.21+0.23 × 1014 M⊙. Conclusions: Our measurements demonstrated the feasibility of using weak lensing magnification as a viable tool for determining the average halo masses for samples of high redshift galaxy clusters. The results also established the success of using galaxy over-densities to select massive clusters at z

Moon illusion and spiral aftereffect: illusions due to the loom-zoom system?

PubMed

Hershenson, M

1982-12-01

The moon illusion and the spiral aftereffect are illusions in which apparent size and apparent distance vary inversely. Because this relationship is exactly opposite to that predicted by the static size--distance invariance hypothesis, the illusions have been called "paradoxical." The illusions may be understood as products of a loom-zoom system, a hypothetical visual subsystem that, in its normal operation, acts according to its structural constraint, the constancy axiom, to produce perceptions that satisfy the constraints of stimulation, the kinetic size--distance invariance hypothesis. When stimulated by its characteristic stimulus of symmetrical expansion or contraction, the loom-zoom system produces the perception of a rigid object moving in depth. If this system is stimulated by a rotating spiral, a negative motion-aftereffect is produced when rotation ceases. If fixation is then shifted to a fixed-sized disc, the aftereffect process alters perceived distance and the loom-zoom system alters perceived size such that the disc appears to expand and approach or to contract and recede, depending on the direction of rotation of the spiral. If the loom-zoom system is stimulated by a moon-terrain configuration, the equidistance tendency produces a foreshortened perceived distance for the moon as an inverse function of elevation and acts in conjunction with the loom-zoom system to produce the increased perceived size of the moon.

Mechanically assisted liquid lens zoom system for mobile phone cameras

NASA Astrophysics Data System (ADS)

Wippermann, F. C.; Schreiber, P.; Bräuer, A.; Berge, B.

2006-08-01

Camera systems with small form factor are an integral part of today's mobile phones which recently feature auto focus functionality. Ready to market solutions without moving parts have been developed by using the electrowetting technology. Besides virtually no deterioration, easy control electronics and simple and therefore cost-effective fabrication, this type of liquid lenses enables extremely fast settling times compared to mechanical approaches. As a next evolutionary step mobile phone cameras will be equipped with zoom functionality. We present first order considerations for the optical design of a miniaturized zoom system based on liquid-lenses and compare it to its mechanical counterpart. We propose a design of a zoom lens with a zoom factor of 2.5 considering state-of-the-art commercially available liquid lens products. The lens possesses auto focus capability and is based on liquid lenses and one additional mechanical actuator. The combination of liquid lenses and a single mechanical actuator enables extremely short settling times of about 20ms for the auto focus and a simplified mechanical system design leading to lower production cost and longer life time. The camera system has a mechanical outline of 24mm in length and 8mm in diameter. The lens with f/# 3.5 provides market relevant optical performance and is designed for an image circle of 6.25mm (1/2.8" format sensor).

Bidimensional Lens Systems : A Rational Approach To Group Displacements During Focusing And/Or Zooming

NASA Astrophysics Data System (ADS)

Angénieux, J. P. L.

1987-06-01

Modern objective lenses for cinematography, television or photography, and particularly zoom lenses, are composed of several groups of lenses which are axially displaced during zooming and/or focusing. The number of these groups has increased recently as well as the complexity of their relative movements and functions. In this paper, we give a short history of zooming and focusing techniques ; we discuss the inconvenience of traditional solutions. We then introduce the concept of bidimensional law. We propose a systematic classification of possible lens-types according to the 4 possible types of group. We finally present a few types of lenses in the form of truth tables and parametered diagrams explaining which groups move and how during focusing and/or zooming.

Effects of dental magnification lenses on indirect vision: a pilot study.

PubMed

Hoerler, Sarah B; Branson, Bonnie G; High, Anne M; Mitchell, Tanya Villalpando

2012-01-01

The purpose of this pilot study was to evaluate the effect of magnification lenses on the indirect vision skills of dental hygiene students. This pilot study examined the accuracy and efficiency of dental hygiene students' indirect vision skills while using traditional safety lenses and magnification lenses. The sample was comprised of 14 students in their final semester of a dental hygiene program. A crossover study approach was utilized, with each participant randomly assigned to a specific order of eyewear. The study included evaluation of each participant taking part in 2 separate clinical sessions. During the first session, each participant completed a clinical exercise on a dental manikin marked with 15 dots throughout the oral cavity while wearing the randomly as signed eyewear, and then completed a similar exercise on a differently marked dental manikin while wearing the randomly assigned eyewear. This procedure was repeated at a second clinical session, however, the dental manikin and eyewear pairings were reversed. Accuracy was measured on the number of correctly identified dots and efficiency was measured by the time it took to identify the dots. Perceptions of the participants' use of magnification lenses and the participants' opinion of the use of magnification lenses in a dental hygiene curriculum were evaluated using a questionnaire. Comparing the mean of the efficiency scores, students are more efficient at identifying indirect vision points with the use of magnification lenses (3 minutes, 36 seconds) than with traditional safety lenses (3 minutes, 56 seconds). Comparing the measurement of accuracy, students are more accurate at identifying indirect vision points with traditional safety lenses (84%) as com pared to magnification lenses (79%). Overall, the students report ed an increased quality of dental hygiene treatment provided in the clinical setting and an improved clinical posture while treating patients with the use of magnification lenses

Development and application of variable-magnification x-ray Bragg optics

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

Hirano, Keiichi, E-mail: keiichi.hirano@kek.jp; Takahashi, Yumiko; Sugiyama, Hiroshi

2016-07-27

A novel x-ray Bragg optics was developed for variable-magnification of an x-ray beam, and was combined with a module of the PILATUS pixel detector. A feasibility test of this optical system was carried out at the vertical-wiggler beamline BL-14B of the Photon Factory. By tuning the magnification factor, we could successfully control the spatial resolution of the optical system between 28 μm and 280 μm. X-ray absorption-contrast images of a leaf were observed at various magnification factors.

Solutions on a high-speed wide-angle zoom lens with aspheric surfaces

NASA Astrophysics Data System (ADS)

Yamanashi, Takanori

2012-10-01

Recent development in CMOS and digital camera technology has accelerated the business and market share of digital cinematography. In terms of optical design, this technology has increased the need to carefully consider pixel pitch and characteristics of the imager. When the field angle at the wide end, zoom ratio, and F-number are specified, choosing an appropriate zoom lens type is crucial. In addition, appropriate power distributions and lens configurations are required. At points near the wide end of a zoom lens, it is known that an aspheric surface is an effective means to correct off-axis aberrations. On the other hand, optical designers have to focus on manufacturability of aspheric surfaces and perform required analysis with respect to the surface shape. Centration errors aside, it is also important to know the sensitivity to aspheric shape errors and their effect on image quality. In this paper, wide angle cine zoom lens design examples are introduced and their main characteristics are described. Moreover, technical challenges are pointed out and solutions are proposed.

Photographic zoom fisheye lens design for DSLR cameras

NASA Astrophysics Data System (ADS)

Yan, Yufeng; Sasian, Jose

2017-09-01

Photographic fisheye lenses with fixed focal length for cameras with different sensor formats have been well developed for decades. However, photographic fisheye lenses with variable focal length are rare on the market due in part to the greater design difficulty. This paper presents a large aperture zoom fisheye lens for DSLR cameras that produces both circular and diagonal fisheye imaging for 35-mm sensors and diagonal fisheye imaging for APS-C sensors. The history and optical characteristics of fisheye lenses are briefly reviewed. Then, a 9.2- to 16.1-mm F/2.8 to F/3.5 zoom fisheye lens design is presented, including the design approach and aberration control. Image quality and tolerance performance analysis for this lens are also presented.

Chromoendoscopy and magnification endoscopy in Barrett's esophagus.

PubMed

Connor, Michael J; Sharma, Prateek

2003-04-01

Chromoendoscopy and magnification endoscopy appear to be a valuable adjuncts for the detection and classification of BE. These techniques may also prove to be useful aids in surveillance protocols for identifying dysplastic epithelium or early cancer within a segment of BE. Ideally, the use of these techniques would enable the endoscopist to rule in or out the presence of IM and of dysplastic or cancerous epithelium by obtaining only a minimal number of targeted biopsy specimens, or potentially performing no biopsies at all. This could transform upper endoscopy into a much more effective screening and surveillance tool for BE. Several problems currently exist for the use of chromoendoscopy for BE. Results of studies reporting the accuracy of chromoendoscopy remain mixed,and are likely explained by the wide range of techniques and materials used in the investigations. Staining adds several steps, and likely several minutes, to an upper endoscopy. Staining within the esophagus is often patchy and uneven. In addition, poor spraying technique exaggerates the irregular uptake by the mucosa. There is a high false-positive rate when staining gastric-type epithelium and denuded epithelium. Areas of dysplasia or cancer may take up stain in an irregular manner, or may not stain at all. Chromoendoscopy is a relatively new technique in the management of BE and depends on the skill and experience of the endoscopist. Magnification, however, only allows the endoscopist to observe small areas of mucosa at a time, increasing the overall complexity and length of the procedure. The learning curve for this procedure is relatively short, however, and endoscopists can usually become proficient in the technique quickly. Currently, the greatest body of literature exists concerning the use of methylene blue for diagnosing BE. At the present time, chromoendoscopy and magnification endoscopy appear to be most beneficial in detecting IM in short segments of esophageal columnar

Contrast-to-noise ratio in magnification mammography: a Monte Carlo study

NASA Astrophysics Data System (ADS)

Koutalonis, M.; Delis, H.; Spyrou, G.; Costaridou, L.; Tzanakos, G.; Panayiotakis, G.

2007-06-01

Magnification views are a common way to perform a secondary examination when suspicious abnormalities are found in a screening mammogram. The visibility of microcalcifications and breast lesions is restricted by the compromise between the image quality and the absorbed dose. In this study, image quality characteristics in magnification mammography were evaluated based on Monte Carlo techniques. A breast phantom was utilized, simulating a homogeneous mixture of adipose and glandular tissue in various percentages of glandularity, containing inhomogeneities of various sizes and compositions. The effect of the magnification degree, breast glandularity, tube voltage and anode/filter material combination on image quality characteristics was investigated in terms of a contrast-to-noise ratio (CNR). A performance index PIν was introduced in order to study the overall performance of various anode/filter combinations under different exposure parameters. Results demonstrate that CNR is improved with the degree of magnification and degraded as the breast glandularity is increased. Degree of magnification 1.3 offers the best overall performance for most of the anode/filter combinations utilized. Under magnification conditions, the role of dose is demoted against the image quality, as magnification views are secondary, diagnostic examinations and not screening procedures oriented to non-symptomatic women. For decreased image quality weighting, some anode/filter combinations different from Mo/0.030mmMo can be utilized as they offer a similar performance index. However, if the desired weighting for the image quality is high, the Mo/0.030mmMo combination has the best overall performance.

Aplanatic Three-Mirror Objective for High-Magnification Soft X-Ray Microscopy

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

Toyoda, M.; Jinno, T.; Yanagihara, M.

2011-09-09

An innovative solution for high-magnification microscopy, based on attaching afocal optics for focal length reduction, is proposed. The solution, consisting of three spherical mirrors, allows one to enhance a magnification of a laboratory based soft x-ray microscope over 1000x, where movies with diffraction-limited resolution can be observed with an x-ray CCD. The design example, having a numerical aperture of 0.25, was successfully demonstrated both a high magnification and a large field of view.

Weak lensing magnification in the Dark Energy Survey Science Verification Data

DOE PAGES

Garcia-Fernandez, M.; et al.

2018-02-02

In this paper the effect of weak lensing magnification on galaxy number counts is studied by cross-correlating the positions of two galaxy samples, separated by redshift, using data from the Dark Energy Survey Science Verification dataset. The analysis is carried out for two photometrically-selected galaxy samples, with mean photometric redshifts in themore » $0.2 < z < 0.4$ and $0.7 < z < 1.0$ ranges, in the riz bands. A signal is detected with a $$3.5\\sigma$$ significance level in each of the bands tested, and is compatible with the magnification predicted by the $$\\Lambda$$CDM model. After an extensive analysis, it cannot be attributed to any known systematic effect. The detection of the magnification signal is robust to estimated uncertainties in the outlier rate of the pho- tometric redshifts, but this will be an important issue for use of photometric redshifts in magnification mesurements from larger samples. In addition to the detection of the magnification signal, a method to select the sample with the maximum signal-to-noise is proposed and validated with data.« less

Weak lensing magnification in the Dark Energy Survey Science Verification Data

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

Garcia-Fernandez, M.; et al.

In this paper the effect of weak lensing magnification on galaxy number counts is studied by cross-correlating the positions of two galaxy samples, separated by redshift, using data from the Dark Energy Survey Science Verification dataset. The analysis is carried out for two photometrically-selected galaxy samples, with mean photometric redshifts in themore » $0.2 < z < 0.4$ and $0.7 < z < 1.0$ ranges, in the riz bands. A signal is detected with a $$3.5\\sigma$$ significance level in each of the bands tested, and is compatible with the magnification predicted by the $$\\Lambda$$CDM model. After an extensive analysis, it cannot be attributed to any known systematic effect. The detection of the magnification signal is robust to estimated uncertainties in the outlier rate of the pho- tometric redshifts, but this will be an important issue for use of photometric redshifts in magnification mesurements from larger samples. In addition to the detection of the magnification signal, a method to select the sample with the maximum signal-to-noise is proposed and validated with data.« less

Weak lensing magnification in the Dark Energy Survey Science Verification Data

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

Garcia-Fernandez, M.; et al.

2016-11-30

In this paper the effect of weak lensing magnification on galaxy number counts is studied by cross-correlating the positions of two galaxy samples, separated by redshift, using data from the Dark Energy Survey Science Verification dataset. The analysis is carried out for two photometrically-selected galaxy samples, with mean photometric redshifts in themore » $0.2 < z < 0.4$ and $0.7 < z < 1.0$ ranges, in the riz bands. A signal is detected with a $$3.5\\sigma$$ significance level in each of the bands tested, and is compatible with the magnification predicted by the $$\\Lambda$$CDM model. After an extensive analysis, it cannot be attributed to any known systematic effect. The detection of the magnification signal is robust to estimated uncertainties in the outlier rate of the pho- tometric redshifts, but this will be an important issue for use of photometric redshifts in magnification mesurements from larger samples. In addition to the detection of the magnification signal, a method to select the sample with the maximum signal-to-noise is proposed and validated with data.« less

Annular ring zoom system using two positive axicons

NASA Astrophysics Data System (ADS)

Dickey, Fred M.; Conner, Jacob D.

2011-10-01

The production of an annular ring of light with a variable diameter has applications in laser material processing and machining, particle manipulation, and corneal surgery. This can readily be accomplished using a positive and negative axicon pair. However, negative axicons are very expensive and difficult to obtain with small diameters. In this paper, we present a design of an annular ring zoom system using two positive axicons. One axicon is placed a distance before a primary lens that is greater than some prescribed minimum, and the second axicon is placed after the primary lens. The position of the second axicon determines the ring diameter. The ring diameter can be zoomed from some maximum design size to a zero diameter ring (spot). Experimental results from a developmental system will be presented.

Estimation of cortical magnification from positional error in normally sighted and amblyopic subjects

PubMed Central

Hussain, Zahra; Svensson, Carl-Magnus; Besle, Julien; Webb, Ben S.; Barrett, Brendan T.; McGraw, Paul V.

2015-01-01

We describe a method for deriving the linear cortical magnification factor from positional error across the visual field. We compared magnification obtained from this method between normally sighted individuals and amblyopic individuals, who receive atypical visual input during development. The cortical magnification factor was derived for each subject from positional error at 32 locations in the visual field, using an established model of conformal mapping between retinal and cortical coordinates. Magnification of the normally sighted group matched estimates from previous physiological and neuroimaging studies in humans, confirming the validity of the approach. The estimate of magnification for the amblyopic group was significantly lower than the normal group: by 4.4 mm deg−1 at 1° eccentricity, assuming a constant scaling factor for both groups. These estimates, if correct, suggest a role for early visual experience in establishing retinotopic mapping in cortex. We discuss the implications of altered cortical magnification for cortical size, and consider other neural changes that may account for the amblyopic results. PMID:25761341

Estimation of Fine-Scale Histologic Features at Low Magnification.

PubMed

Zarella, Mark D; Quaschnick, Matthew R; Breen, David E; Garcia, Fernando U

2018-06-18

- Whole-slide imaging has ushered in a new era of technology that has fostered the use of computational image analysis for diagnostic support and has begun to transfer the act of analyzing a slide to computer monitors. Due to the overwhelming amount of detail available in whole-slide images, analytic procedures-whether computational or visual-often operate at magnifications lower than the magnification at which the image was acquired. As a result, a corresponding reduction in image resolution occurs. It is unclear how much information is lost when magnification is reduced, and whether the rich color attributes of histologic slides can aid in reconstructing some of that information. - To examine the correspondence between the color and spatial properties of whole-slide images to elucidate the impact of resolution reduction on the histologic attributes of the slide. - We simulated image resolution reduction and modeled its effect on classification of the underlying histologic structure. By harnessing measured histologic features and the intrinsic spatial relationships between histologic structures, we developed a predictive model to estimate the histologic composition of tissue in a manner that exceeds the resolution of the image. - Reduction in resolution resulted in a significant loss of the ability to accurately characterize histologic components at magnifications less than ×10. By utilizing pixel color, this ability was improved at all magnifications. - Multiscale analysis of histologic images requires an adequate understanding of the limitations imposed by image resolution. Our findings suggest that some of these limitations may be overcome with computational modeling.

Creating Catch 22: Zooming in and Zooming out on the Discursive Constructions of Teachers in a News Article

ERIC Educational Resources Information Center

Keogh, Jayne; Garrick, Barbara

2011-01-01

The media regularly present negative news articles about teachers and teaching. This paper focuses particularly on one such news article. Using reflective analytic practices, first we zoom in to conduct a detailed analysis of the text. We find that complex and contradictory moral categories of teachers are assembled within and through the text. We…

Improving the Quality and Scientific Understanding of Trophic Magnification Factors (TMFs)

EPA Science Inventory

This short 1000 word report presents a series of research needs for improving the measurement and understanding of trophic magnification factors (TMFs). TMFs are useful measures of trophic magnification and represent the diet-weighted average biomagnification factor (BMF) of che...

Research on the relation between the contact angle and the interface curvature radius of electrowetting liquid zoom lens

NASA Astrophysics Data System (ADS)

Zhao, Cunhua; Liang, Huiqin; Cui, Dongqing; Hong, Xinhua; Wei, Daling; Gao, Changliu

2011-08-01

In the ultralight or ultrathin applied domain of zoom lens, the traditional glass / plastic lens is limited for manufacture technology or cost. Therefore, a liquid lens was put forward to solve the problems. The liquid zoom lens has the merits of lower cost, smaller volume, quicker response, lower energy consumption, continuous zoom and higher accuracy. In liquid zoom lens the precise focal length is obtained by the contact angle changing to affect the curvature radius of interface. In our works, the relations of the exerted voltage, the contact angle, the curvature radius and the focal length were researched and accurately calculated. The calculation of the focal length provides an important theoretical basis for instructing the design of liquid zoom lens.

Experimental Demonstration of Longitudinal Magnification

ERIC Educational Resources Information Center

Razpet, Nada; Susman, Katarina; Cepic, Mojca

2009-01-01

We describe an experiment which enables the observation of longitudinal magnification for the real image of a three-dimensional (3D) object formed by a converging lens. The experiment also shows the absence of longitudinal inversion. Possible reasons for misconceptions with respect to real images and longitudinal inversions are discussed and a…

Dipolar modulation in the size of galaxies: the effect of Doppler magnification

NASA Astrophysics Data System (ADS)

Bonvin, Camille; Andrianomena, Sambatra; Bacon, David; Clarkson, Chris; Maartens, Roy; Moloi, Teboho; Bull, Philip

2017-12-01

Objects falling into an overdensity appear larger on its near side and smaller on its far side than other objects at the same redshift. This produces a dipolar pattern of magnification, primarily as a consequence of the Doppler effect. At low redshift, this Doppler magnification completely dominates the usual integrated gravitational lensing contribution to the lensing magnification. We show that one can optimally observe this pattern by extracting the dipole in the cross-correlation of number counts and galaxy sizes. This dipole allows us to almost completely remove the contribution from gravitational lensing up to redshift ≲0.5, and even at high redshift z ≃ 1, the dipole picks up the Doppler magnification predominantly. Doppler magnification should be easily detectable in current and upcoming optical and radio surveys; by forecasting for telescopes such as the SKA, we show that this technique is competitive with using peculiar velocities via redshift-space distortions to constrain dark energy. It produces similar yet complementary constraints on the cosmological model to those found using measurements of the cosmic shear.

Newly described features resulting from high-magnification dermoscopy of tinea capitis.

PubMed

Lacarrubba, Francesco; Verzì, Anna Elisa; Micali, Giuseppe

2015-03-01

Recent studies have reported "comma hairs" as a typical dermoscopic feature of tinea capitis observed at low magnification (×10). The aim of this study was to evaluate the dermoscopic aspects of tinea capitis at high magnification (×150) and its diagnostic role. Five children (2 boys and 3 girls; aged 4-10 years) with multiple scaly patches of alopecia underwent scalp dermoscopy, direct microscopic examinations, and mycological cultures of skin scrapings. Using low magnification (×30), typical comma hairs, "Morse code-like" hairs, and "zigzag" hairs were observed. When using high magnification (×150), additional features were horizontal white bands that appear as empty bands that are likely related to localized areas of fungal infection. These horizontal white bands are usually multiple and may cause the hair to bend and break. We also identified a new dermoscopic feature consisting of translucent, easily deformable hairs that look weakened and transparent and show unusual bends; they are likely the result of a massive fungal invasion involving the whole hair shaft. Direct microscopic examination showed fungal infection and results of mycological culture were positive for Microsporum canis in all cases. The identification of new findings using higher-magnification dermoscopy may enhance the diagnosis of tinea capitis and be of help to better understand some pathogenetic mechanisms.

Geographic Data Display Implementation

DTIC Science & Technology

1977-06-01

display to be either multiplied or divided by the magnification factor (normally 1.5). The result is a change of extent around the cursor as seen in... Products printer and a 200-card- per-minute card reader with the Interdata 4 (1-4). The 1-4 with its 64K of core is the applications machine connected...storing these values in the CURSTA array. 57 ZOOM IN FUNCTION KEY ZOOM OUT FUNCTION KEY ZMINTP ZMOUTP SET ZOOM OUT MAG FACTOR ZOMTOP SET

Anisotropic magnification distortion of the 3D galaxy correlation. I. Real space

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

Hui, Lam; LoVerde, Marilena; Department of Physics, Columbia University, New York, New York 10027

2007-11-15

It has long been known that gravitational lensing, primarily via magnification bias, modifies the observed galaxy (or quasar) clustering. Such discussions have largely focused on the 2D angular correlation function. Here and in paper II [L. Hui, E. Gaztanaga, and M. LoVerde, arXiv:0710.4191] we explore how magnification bias distorts the 3D correlation function and power spectrum, as first considered by Matsubara [Astrophys. J. Lett. 537, L77 (2000).]. The interesting point is that the distortion is anisotropic. Magnification bias in general preferentially enhances the observed correlation in the line-of-sight (LOS) orientation, especially on large scales. For instance, at a LOS separationmore » of {approx}100 Mpc/h, where the intrinsic galaxy-galaxy correlation is rather weak, the observed correlation can be enhanced by lensing by a factor of a few, even at a modest redshift of z{approx}0.35. This effect presents an interesting opportunity as well as a challenge. The opportunity: this lensing anisotropy is distinctive, making it possible to separately measure the galaxy-galaxy, galaxy-magnification, and magnification-magnification correlations, without measuring galaxy shapes. The anisotropy is distinguishable from the well-known distortion due to peculiar motions, as will be discussed in paper II. The challenge: the magnification distortion of the galaxy correlation must be accounted for in interpreting data as precision improves. For instance, the {approx}100 Mpc/h baryon acoustic oscillation scale in the correlation function is shifted by up to {approx}3% in the LOS orientation, and up to {approx}0.6% in the monopole, depending on the galaxy bias, redshift, and number count slope. The corresponding shifts in the inferred Hubble parameter and angular diameter distance, if ignored, could significantly bias measurements of the dark energy equation of state. Lastly, magnification distortion offers a plausible explanation for the well-known excess correlations

MAGNIFICENT MAGNIFICATION: EXPLOITING THE OTHER HALF OF THE LENSING SIGNAL

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

Huff, Eric M.; Graves, Genevieve J.

2014-01-10

We describe a new method for measuring galaxy magnification due to weak gravitational lensing. Our method makes use of a tight scaling relation between galaxy properties that are modified by gravitational lensing, such as apparent size, and other properties that are not, such as surface brightness. In particular, we use a version of the well-known fundamental plane relation for early-type galaxies. This modified ''photometric fundamental plane'' uses only photometric galaxy properties, eliminating the need for spectroscopic data. We present the first detection of magnification using this method by applying it to photometric catalogs from the Sloan Digital Sky Survey. Thismore » analysis shows that the derived magnification signal is within a factor of three of that available from conventional methods using gravitational shear. We suppress the dominant sources of systematic error and discuss modest improvements that may further enhance the lensing signal-to-noise available with this method. Moreover, some of the dominant sources of systematic error are substantially different from those of shear-based techniques. With this new technique, magnification becomes a useful measurement tool for the coming era of large ground-based surveys intending to measure gravitational lensing.« less

A PLANETARY LENSING FEATURE IN CAUSTIC-CROSSING HIGH-MAGNIFICATION MICROLENSING EVENTS

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

Chung, Sun-Ju; Hwang, Kyu-Ha; Ryu, Yoon-Hyun

Current microlensing follow-up observations focus on high-magnification events because of the high efficiency of planet detection. However, central perturbations of high-magnification events caused by a planet can also be produced by a very close or a very wide binary companion, and the two kinds of central perturbations are not generally distinguished without time consuming detailed modeling (a planet-binary degeneracy). Hence, it is important to resolve the planet-binary degeneracy that occurs in high-magnification events. In this paper, we investigate caustic-crossing high-magnification events caused by a planet and a wide binary companion. From this investigation, we find that because of the differentmore » magnification excess patterns inside the central caustics induced by the planet and the binary companion, the light curves of the caustic-crossing planetary-lensing events exhibit a feature that is discriminated from those of the caustic-crossing binary-lensing events, and the feature can be used to immediately distinguish between the planetary and binary companions. The planetary-lensing feature appears in the interpeak region between the two peaks of the caustic-crossings. The structure of the interpeak region for the planetary-lensing events is smooth and convex or boxy, whereas the structure for the binary-lensing events is smooth and concave. We also investigate the effect of a finite background source star on the planetary-lensing feature in the caustic-crossing high-magnification events. From this, we find that the convex-shaped interpeak structure appears in a certain range that changes with the mass ratio of the planet to the planet-hosting star.« less

Chromatic correction for a VIS-SWIR zoom lens using optical glasses

NASA Astrophysics Data System (ADS)

Zhao, Yang; Williams, Daniel J. L.; McCarthy, Peter; Visconti, Anthony J.; Bentley, Julie L.; Moore, Duncan T.

2015-09-01

With the advancement in sensors, hyperspectral imaging in short wave infrared (SWIR 0.9 μm to 1.7 μm) now has wide applications, including night vision, haze-penetrating imaging, etc. Most conventional optical glasses can be material candidates for designing in the SWIR as they transmit up to 2.2 μm. However, since SWIR is in the middle of the glasses' major absorption wavebands in UV and IR, the flint glasses in SWIR are less dispersive than in the visible spectrum. As a result, the glass map in the SWIR is highly compressed, with crowns and flints all clustering together. Thus correcting for chromatic aberration is more challenging in the SWIR, since the Abbé number ratio of the same glass combination is reduced. Conventionally, fluorides, such as CaF2 and BaF2, are widely used in designing SWIR system due to their unique dispersion properties, even though they are notorious for poor manufacturability or even high toxicity. For lens elements in a zoom system, the ray bundle samples different sections of the each lens aperture as the lens zooms. This creates extra uncertainty in correcting chromatic aberrations. This paper focuses on using only commercially available optical glasses to color-correct a 3X dual-band zoom lens system in the VIS-SWIR. The design tools and techniques are detailed in terms of material selections to minimize the chromatic aberrations in such a large spectrum band and all zoom positions. Examples are discussed for designs with different aperture stop locations, which considerably affect the material choices.

Automated magnification calibration in transmission electron microscopy using Fourier analysis of replica images.

PubMed

van der Laak, Jeroen A W M; Dijkman, Henry B P M; Pahlplatz, Martin M M

2006-03-01

The magnification factor in transmission electron microscopy is not very precise, hampering for instance quantitative analysis of specimens. Calibration of the magnification is usually performed interactively using replica specimens, containing line or grating patterns with known spacing. In the present study, a procedure is described for automated magnification calibration using digital images of a line replica. This procedure is based on analysis of the power spectrum of Fourier transformed replica images, and is compared to interactive measurement in the same images. Images were used with magnification ranging from 1,000 x to 200,000 x. The automated procedure deviated on average 0.10% from interactive measurements. Especially for catalase replicas, the coefficient of variation of automated measurement was considerably smaller (average 0.28%) compared to that of interactive measurement (average 3.5%). In conclusion, calibration of the magnification in digital images from transmission electron microscopy may be performed automatically, using the procedure presented here, with high precision and accuracy.

Magnifications of Single and Dual Element Accommodative Intraocular Lenses: Paraxial Optics Analysis

PubMed Central

Ale, Jit B; Manns, Fabrice; Ho, Arthur

2010-01-01

Purpose Using an analytical approach of paraxial optics, we evaluated the magnification of a model eye implanted with single-element (1E) and dual-element (2E) translating-optics accommodative intraocular lenses (AIOL) with an objective of understanding key control parameters relevant to their design. Potential clinical implications of the results arising from pseudophakic accommodation were also considered. Methods Lateral and angular magnifications in a pseudophakic model eye were analyzed using the matrix method of paraxial optics. The effects of key control parameters such as direction (forward or backward) and distance (0 to 2 mm) of translation, power combinations of the 2E-AIOL elements (front element power range +20.0 D to +40.0 D), and amplitudes of accommodation (0 to 4 D) were tested. Relative magnification, defined as the ratio of the retinal image size of the accommodated eye to that of unaccommodated phakic (rLM1) or pseudophakic (rLM2) model eyes, was computed to determine how retinal image size changes with pseudophakic accommodation. Results Both lateral and angular magnifications increased with increased power of the front element in 2E-AIOL and amplitude of accommodation. For a 2E-AIOL with front element power of +35 D, rLM1 and rLM2 increased by 17.0% and 16.3%, respectively, per millimetre of forward translation of the element, compared to the magnification at distance focus (unaccommodated). These changes correspond to a change of 9.4% and 6.5% per dioptre of accommodation, respectively. Angular magnification also increased with pseudophakic accommodation. 1E-AIOLs produced consistently less magnification than 2E-AIOLs. Relative retinal image size decreased at a rate of 0.25% with each dioptre of accommodation in the phakic model eye. The position of the image space nodal point shifted away from the retina (towards the cornea) with both phakic and pseudophakic accommodation. Conclusion Power of the mobile element, and amount and direction of

An all-silicone zoom lens in an optical imaging system

NASA Astrophysics Data System (ADS)

Zhao, Cun-Hua

2013-09-01

An all-silicone zoom lens is fabricated. A tunable metal ringer is fettered around the side edge of the lens. A nylon rope linking a motor is tied, encircling the notch in the metal ringer. While the motor is operating, the rope can shrink or release to change the focal length of the lens. A calculation method is developed to obtain the focal length and the zoom ratio. The testing is carried out in succession. The testing values are compared with the calculated ones, and they tally with each other well. Finally, the imaging performance of the all-silicone lens is demonstrated. The all-silicone lens has potential uses in cellphone cameras, notebook cameras, micro monitor lenses, etc.

The effect of magnification loupes on the performance of preclinical dental students.

PubMed

Maggio, Margrit P; Villegas, Hilda; Blatz, Markus B

2011-01-01

optical magnifying devices such as magnification loupes are increasingly used in clinical practice and educational settings. However, scientific evidence to validate their benefits is limited. This study assessed the effect of dental magnification loupes on psychomotor skill acquisition during a preclinical operative dentistry course. the performance of first-year dental students was assessed during an Advanced Simulation Course (AS) using virtual reality-based technology (VRBT) training. The test group consisted of 116 dental students using magnification loupes (+MAG), while students not using them (-MAG, n = 116) served as the control. The following parameters were evaluated: number of successfully passing preparation procedures per course rotation, amount of time per tooth preparation, number of times students needed computer assistance and evaluation, and amount of time spent in the computer assistance and evaluation mode per procedure. Data were collected on each student through VRBT during the preparation procedure and stored on a closed network server computer. Unpaired t tests were used to analyze mean differences between the groups. In addition, student acceptance of magnification loupes was measured and evaluated through survey interpretation. +MAG students completed more preparations, worked faster per procedure, and used the computer-assisted evaluation less frequently and for shorter periods, therefore displaying greater overall performance. The survey revealed a high degree of student acceptance of using magnification. dental magnification loupes significantly enhanced student performance during preclinical dental education and were considered an effective adjunct by the students who used them.

Joint demosaicking and zooming using moderate spectral correlation and consistent edge map

NASA Astrophysics Data System (ADS)

Zhou, Dengwen; Dong, Weiming; Chen, Wengang

2014-07-01

The recently published joint demosaicking and zooming algorithms for single-sensor digital cameras all overfit the popular Kodak test images, which have been found to have higher spectral correlation than typical color images. Their performance perhaps significantly degrades on other datasets, such as the McMaster test images, which have weak spectral correlation. A new joint demosaicking and zooming algorithm is proposed for the Bayer color filter array (CFA) pattern, in which the edge direction information (edge map) extracted from the raw CFA data is consistently used in demosaicking and zooming. It also moderately utilizes the spectral correlation between color planes. The experimental results confirm that the proposed algorithm produces an excellent performance on both the Kodak and McMaster datasets in terms of both subjective and objective measures. Our algorithm also has high computational efficiency. It provides a better tradeoff among adaptability, performance, and computational cost compared to the existing algorithms.

Implementation of focal zooming on the Nike KrF laser

NASA Astrophysics Data System (ADS)

Kehne, D. M.; Karasik, M.; Aglitsky, Y.; Smyth, Z.; Terrell, S.; Weaver, J. L.; Chan, Y.; Lehmberg, R. H.; Obenschain, S. P.

2013-01-01

In direct drive inertial confinement laser fusion, a pellet containing D-T fuel is imploded by ablation arising from absorption of laser energy at its outer surface. For optimal coupling, the focal spot of the laser would continuously decrease to match the reduction in the pellet's diameter, thereby minimizing wasted energy. A krypton-fluoride laser (λ = 248 nm) that incorporates beam smoothing by induced spatial incoherence has the ability to produce a high quality focal profile whose diameter varies with time, a property known as focal zooming. A two-stage focal zoom has been demonstrated on the Nike laser at the Naval Research Laboratory. In the experiment, a 4.4 ns laser pulse was created in which the on-target focal spot diameter was 1.3 mm (full width at half maximum) for the first 2.4 ns and 0.28 mm for the final 2 ns. These two diameters appear in time-integrated focal plane equivalent images taken at several locations in the amplification chain. Eight of the zoomed output beams were overlapped on a 60 μm thick planar polystyrene target. Time resolved images of self-emission from the rear of the target show the separate shocks launched by the two corresponding laser focal diameters.

Implementation of focal zooming on the Nike KrF laser.

PubMed

Kehne, D M; Karasik, M; Aglitsky, Y; Smyth, Z; Terrell, S; Weaver, J L; Chan, Y; Lehmberg, R H; Obenschain, S P

2013-01-01

In direct drive inertial confinement laser fusion, a pellet containing D-T fuel is imploded by ablation arising from absorption of laser energy at its outer surface. For optimal coupling, the focal spot of the laser would continuously decrease to match the reduction in the pellet's diameter, thereby minimizing wasted energy. A krypton-fluoride laser (λ = 248 nm) that incorporates beam smoothing by induced spatial incoherence has the ability to produce a high quality focal profile whose diameter varies with time, a property known as focal zooming. A two-stage focal zoom has been demonstrated on the Nike laser at the Naval Research Laboratory. In the experiment, a 4.4 ns laser pulse was created in which the on-target focal spot diameter was 1.3 mm (full width at half maximum) for the first 2.4 ns and 0.28 mm for the final 2 ns. These two diameters appear in time-integrated focal plane equivalent images taken at several locations in the amplification chain. Eight of the zoomed output beams were overlapped on a 60 μm thick planar polystyrene target. Time resolved images of self-emission from the rear of the target show the separate shocks launched by the two corresponding laser focal diameters.

Toward an improved haptic zooming algorithm for graphical information accessed by individuals who are blind and visually impaired.

PubMed

Rastogi, Ravi; Pawluk, Dianne T V

2013-01-01

An increasing amount of information content used in school, work, and everyday living is presented in graphical form. Unfortunately, it is difficult for people who are blind or visually impaired to access this information, especially when many diagrams are needed. One problem is that details, even in relatively simple visual diagrams, can be very difficult to perceive using touch. With manually created tactile diagrams, these details are often presented in separate diagrams which must be selected from among others. Being able to actively zoom in on an area of a single diagram so that the details can be presented at a reasonable size for exploration purposes seems a simpler approach for the user. However, directly using visual zooming methods have some limitations when used haptically. Therefore, a new zooming method is proposed to avoid these pitfalls. A preliminary experiment was performed to examine the usefulness of the algorithm compared to not using zooming. The results showed that the number of correct responses improved with the developed zooming algorithm and participants found it to be more usable than not using zooming for exploration of a floor map.

Zoom Reconstruction Tool: Evaluation of Image Quality and Influence on the Diagnosis of Root Fracture.

PubMed

Queiroz, Polyane Mazucatto; Santaella, Gustavo Machado; Capelozza, Ana Lúcia Alvares; Rosalen, Pedro Luiz; Freitas, Deborah Queiroz; Haiter-Neto, Francisco

2018-04-01

This study evaluated the image quality and the diagnosis of root fractures when using the Zoom Reconstruction tool (J Morita, Kyoto, Japan). A utility wax phantom with a metal sample inside was used for objective evaluation, and a mandible with 27 single-rooted teeth (with and without obturation and with and without vertical or horizontal fractures) was used for diagnostic evaluation. The images were acquired in 3 protocols: protocol 1, field of view (FOV) of 4 × 4 cm and a voxel size of 0.08 mm; protocol 2, FOV of 10 × 10 cm and a voxel size of 0.2 mm; and protocol 3, Zoom Reconstruction of images from protocol 2 (FOV of 4 × 4 cm and a voxel size of 0.08 mm). The objective evaluation was achieved by measuring the image noise, and the diagnosis of fractures was performed by 3 evaluators. The area under the receiver operating characteristic curve was used to calculate accuracy, and analysis of variance compared the accuracy and image quality of the protocols. Regarding quality, protocol 1 was superior to protocol 2 (P < .0001) and Zoom Reconstruction (P < .0001). Additionally, images of protocol 2 presented less noise than the Zoom Reconstruction image (P < .0001); however, for diagnosis, Zoom Reconstruction was superior in relation to protocol 2 (P = .011) and did not differ from protocol 1 (P = .228) for the diagnosis of a vertical root fracture in filled teeth. The Zoom Reconstruction tool allows better accuracy for vertical root fracture detection in filled teeth, making it possible to obtain a higher-resolution image from a lower-resolution examination without having to expose the patient to more radiation. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Electrowetting-actuated zoom lens with spherical-interface liquid lenses.

PubMed

Peng, Runling; Chen, Jiabi; Zhuang, Songlin

2008-11-01

The interface shape of two immiscible liquids in a conical chamber is discussed. The analytical solution of the differential equation describing the interface shape shows that the interface shape is completely spherical when the density difference of two liquids is zero. On the basis of the spherical-interface shape and an energy-minimization method, explicit calculations and detailed analyses of an extended Young-type equation for the conical double-liquid lens are given. Finally, a novel design of a zoom lens system without motorized movements is proposed. The lens system consists of a fixed lens and two conical double-liquid variable-focus lenses. The structure and principle of the lens system are introduced in this paper. Taking finite objects as example, detailed calculations and simulation examples are presented to predict how two liquid lenses are related to meet the basic requirements of zoom lenses.

Magnification bias as a novel probe for primordial magnetic fields

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

Camera, S.; Fedeli, C.; Moscardini, L., E-mail: stefano.camera@tecnico.ulisboa.pt, E-mail: cosimo.fedeli@oabo.inaf.it, E-mail: lauro.moscardini@unibo.it

2014-03-01

In this paper we investigate magnetic fields generated in the early Universe. These fields are important candidates at explaining the origin of astrophysical magnetism observed in galaxies and galaxy clusters, whose genesis is still by and large unclear. Compared to the standard inflationary power spectrum, intermediate to small scales would experience further substantial matter clustering, were a cosmological magnetic field present prior to recombination. As a consequence, the bias and redshift distribution of galaxies would also be modified. Hitherto, primordial magnetic fields (PMFs) have been tested and constrained with a number of cosmological observables, e.g. the cosmic microwave background radiation,more » galaxy clustering and, more recently, weak gravitational lensing. Here, we explore the constraining potential of the density fluctuation bias induced by gravitational lensing magnification onto the galaxy-galaxy angular power spectrum. Such an effect is known as magnification bias. Compared to the usual galaxy clustering approach, magnification bias helps in lifting the pathological degeneracy present amongst power spectrum normalisation and galaxy bias. This is because magnification bias cross-correlates galaxy number density fluctuations of nearby objects with weak lensing distortions of high-redshift sources. Thus, it takes advantage of the gravitational deflection of light, which is insensitive to galaxy bias but powerful in constraining the density fluctuation amplitude. To scrutinise the potentiality of this method, we adopt a deep and wide-field spectroscopic galaxy survey. We show that magnification bias does contain important information on primordial magnetism, which will be useful in combination with galaxy clustering and shear. We find we shall be able to rule out at 95.4% CL amplitudes of PMFs larger than 5 × 10{sup −4} nG for values of the PMF power spectral index n{sub B} ∼ 0.« less

Cluster mass profile reconstruction with size and flux magnification on the HST STAGES survey.

PubMed

Duncan, Christopher A J; Heymans, Catherine; Heavens, Alan F; Joachimi, Benjamin

2016-03-21

We present the first measurement of individual cluster mass estimates using weak lensing size and flux magnification. Using data from the HST STAGES (Space Telescope A901/902 Galaxy Evolution Survey) survey of the A901/902 supercluster we detect the four known groups in the supercluster at high significance using magnification alone. We discuss the application of a fully Bayesian inference analysis, and investigate a broad range of potential systematics in the application of the method. We compare our results to a previous weak lensing shear analysis of the same field finding the recovered signal-to-noise of our magnification-only analysis to range from 45 to 110 per cent of the signal-to-noise in the shear-only analysis. On a case-by-case basis we find consistent magnification and shear constraints on cluster virial radius, and finding that for the full sample, magnification constraints to be a factor 0.77 ± 0.18 lower than the shear measurements.

Bias magnification in ecologic studies: a methodological investigation

PubMed Central

Webster, Thomas F

2007-01-01

Background As ecologic studies are often inexpensive to conduct, consideration of the magnitude and direction of ecologic biases may be useful in both study design and sensitivity analysis of results. This paper examines three types of ecologic bias: confounding by group, effect measure modification by group, and non-differential exposure misclassification. Methods Bias of the risk difference on the individual and ecologic levels are compared using two-by-two tables, simple equations, and risk diagrams. Risk diagrams provide a convenient way to simultaneously display information from both levels. Results Confounding by group and effect measure modification by group act in the same direction on the individual and group levels, but have larger impact on the latter. The reduction in exposure variance caused by aggregation magnifies the individual level bias due to ignoring groups. For some studies, the magnification factor can be calculated from the ecologic data alone. Small magnification factors indicate little bias beyond that occurring at the individual level. Aggregation is also responsible for the different impacts of non-differential exposure misclassification on individual and ecologic studies. Conclusion The analytical tools developed here are useful in analyzing ecologic bias. The concept of bias magnification may be helpful in designing ecologic studies and performing sensitivity analysis of their results. PMID:17615079

Stereoscopic 3D reconstruction using motorized zoom lenses within an embedded system

NASA Astrophysics Data System (ADS)

Liu, Pengcheng; Willis, Andrew; Sui, Yunfeng

2009-02-01

This paper describes a novel embedded system capable of estimating 3D positions of surfaces viewed by a stereoscopic rig consisting of a pair of calibrated cameras. Novel theoretical and technical aspects of the system are tied to two aspects of the design that deviate from typical stereoscopic reconstruction systems: (1) incorporation of an 10x zoom lens (Rainbow- H10x8.5) and (2) implementation of the system on an embedded system. The system components include a DSP running μClinux, an embedded version of the Linux operating system, and an FPGA. The DSP orchestrates data flow within the system and performs complex computational tasks and the FPGA provides an interface to the system devices which consist of a CMOS camera pair and a pair of servo motors which rotate (pan) each camera. Calibration of the camera pair is accomplished using a collection of stereo images that view a common chess board calibration pattern for a set of pre-defined zoom positions. Calibration settings for an arbitrary zoom setting are estimated by interpolation of the camera parameters. A low-computational cost method for dense stereo matching is used to compute depth disparities for the stereo image pairs. Surface reconstruction is accomplished by classical triangulation of the matched points from the depth disparities. This article includes our methods and results for the following problems: (1) automatic computation of the focus and exposure settings for the lens and camera sensor, (2) calibration of the system for various zoom settings and (3) stereo reconstruction results for several free form objects.

Comparing the imaging performance of computed super resolution and magnification tomosynthesis

NASA Astrophysics Data System (ADS)

Maidment, Tristan D.; Vent, Trevor L.; Ferris, William S.; Wurtele, David E.; Acciavatti, Raymond J.; Maidment, Andrew D. A.

2017-03-01

Computed super-resolution (SR) is a method of reconstructing images with pixels that are smaller than the detector element size; superior spatial resolution is achieved through the elimination of aliasing and alteration of the sampling function imposed by the reconstructed pixel aperture. By comparison, magnification mammography is a method of projection imaging that uses geometric magnification to increase spatial resolution. This study explores the development and application of magnification digital breast tomosynthesis (MDBT). Four different acquisition geometries are compared in terms of various image metrics. High-contrast spatial resolution was measured in various axes using a lead star pattern. A modified Defrise phantom was used to determine the low-frequency spatial resolution. An anthropomorphic phantom was used to simulate clinical imaging. Each experiment was conducted at three different magnifications: contact (1.04x), MAG1 (1.3x), and MAG2 (1.6x). All images were taken on our next generation tomosynthesis system, an in-house solution designed to optimize SR. It is demonstrated that both computed SR and MDBT (MAG1 and MAG2) provide improved spatial resolution over non-SR contact imaging. To achieve the highest resolution, SR and MDBT should be combined. However, MDBT is adversely affected by patient motion at higher magnifications. In addition, MDBT requires more radiation dose and delays diagnosis, since MDBT would be conducted upon recall. By comparison, SR can be conducted with the original screening data. In conclusion, this study demonstrates that computed SR and MDBT are both viable methods of imaging the breast.

Mitigation of cross-beam energy transfer: Implication of two-state focal zooming on OMEGA

NASA Astrophysics Data System (ADS)

Froula, D. H.; Kessler, T. J.; Igumenshchev, I. V.; Betti, R.; Goncharov, V. N.; Huang, H.; Hu, S. X.; Hill, E.; Kelly, J. H.; Meyerhofer, D. D.; Shvydky, A.; Zuegel, J. D.

2013-08-01

Cross-beam energy transfer (CBET) during OMEGA low-adiabat cryogenic experiments reduces the hydrodynamic efficiency by ˜35%, which lowers the calculated one-dimensional (1-D) yield by a factor of 7. CBET can be mitigated by reducing the diameter of the laser beams relative to the target diameter. Reducing the diameter of the laser beams by 30%, after a sufficient conduction zone has been generated (two-state zooming), is predicted to maintain low-mode uniformity while recovering 90% of the kinetic energy lost to CBET. A radially varying phase plate is proposed to implement two-state zooming on OMEGA. A beam propagating through the central half-diameter of the phase plate will produce a large spot, while a beam propagating through the outer annular region of the phase plate will produce a narrower spot. To generate the required two-state near-field laser-beam profile, a picket driver with smoothing by spectral dispersion (SSD) would pass through an apodizer, forming a beam of half the standard diameter. A second main-pulse driver would co-propagate without SSD through its own apodizer, forming a full-diameter annular beam. Hydrodynamic simulations, using the designed laser spots produced by the proposed zooming scheme on OMEGA, show that implementing zooming will increase the implosion velocity by 25% resulting in a 4.5× increase in the 1-D neutron yield. Demonstrating zooming on OMEGA would validate a viable direct-drive CBET mitigation scheme and help establish a pathway to hydrodynamically equivalent direct-drive-ignition implosions by increasing the ablation pressure (1.6×), which will allow for more stable implosions at ignition-relevant velocities.

Spatial resolution of a spherical x-ray crystal spectrometer at various magnifications

DOE PAGES

Gao, Lan; Hill, K. W.; Bitter, M.; ...

2016-08-23

Here, a high spatial resolution of a few μm is often required for probing small-scale high-energy-density plasmas using high resolution x-ray imaging spectroscopy. This resolution can be achieved by adjusting system magnification to overcome the inherent limitation of the detector pixel size. Laboratory experiments on investigating the relation between spatial resolution and system magnification for a spherical crystal spectrometer are presented. Tungsten Lβ 2 rays from a tungsten-target micro-focus x-ray tube were diffracted by a Ge 440 crystal, which was spherically bent to a radius of 223 mm, and imaged onto an x-ray CCD with 13-μm pixel size. The source-to-crystalmore » (p) and crystal-to-detector (q) distances were varied to produce spatial magnifications ( M = q/p) ranging from 2 to 10. The inferred instrumental spatial width reduces with increasing system magnification M. However, the experimental measurement at each M is larger than the theoretical value of pixel size divided by M. Future work will focus on investigating possible broadening mechanisms that limit the spatial resolution.« less

New long-zoom lens for 4K super 35mm digital cameras

NASA Astrophysics Data System (ADS)

Thorpe, Laurence J.; Usui, Fumiaki; Kamata, Ryuhei

2015-05-01

The world of television production is beginning to adopt 4K Super 35 mm (S35) image capture for a widening range of program genres that seek both the unique imaging properties of that large image format and the protection of their program assets in a world anticipating future 4K services. Documentary and natural history production in particular are transitioning to this form of production. The nature of their shooting demands long zoom lenses. In their traditional world of 2/3-inch digital HDTV cameras they have a broad choice in portable lenses - with zoom ranges as high as 40:1. In the world of Super 35mm the longest zoom lens is limited to 12:1 offering a telephoto of 400mm. Canon was requested to consider a significantly longer focal range lens while severely curtailing its size and weight. Extensive computer simulation explored countless combinations of optical and optomechanical systems in a quest to ensure that all operational requests and full 4K performance could be met. The final lens design is anticipated to have applications beyond entertainment production, including a variety of security systems.

Mathematics of gravitational lensing: multiple imaging and magnification

NASA Astrophysics Data System (ADS)

Petters, A. O.; Werner, M. C.

2010-09-01

The mathematical theory of gravitational lensing has revealed many generic and global properties. Beginning with multiple imaging, we review Morse-theoretic image counting formulas and lower bound results, and complex-algebraic upper bounds in the case of single and multiple lens planes. We discuss recent advances in the mathematics of stochastic lensing, discussing a general formula for the global expected number of minimum lensed images as well as asymptotic formulas for the probability densities of the microlensing random time delay functions, random lensing maps, and random shear, and an asymptotic expression for the global expected number of micro-minima. Multiple imaging in optical geometry and a spacetime setting are treated. We review global magnification relation results for model-dependent scenarios and cover recent developments on universal local magnification relations for higher order caustics.

Effect of coriolis force on forced response magnification of intentionally mistuned bladed disk

NASA Astrophysics Data System (ADS)

Kan, Xuanen; Xu, Zili; Zhao, Bo; Zhong, Jize

2017-07-01

Blade manufacturing tolerance and wear in operation may induce mistuning, and mistuning will lead to vibration localization which will result in destruction of bladed disk. Generally, intentional mistuning has been widely investigated to control the maximum forced response. On the other hand, it should be noted that the bladed disk with high rotational speed is obviously subjected to the Coriolis force. However, the Coriolis force is not included in intentionally mistuned bladed disk in previous studies. Therefore, this paper is to study the effect of the Coriolis force on forced response magnification of intentionally mistuned bladed disk. Finite element method is used to calculate the harmonic response of the intentionally mistuned bladed disk with and without the Coriolis force. The effects of intentional mistuning strength and different integer harmonic order on the response magnification factor with the Coriolis force are discussed. It should be pointed out that, when the integer harmonic order is 1, 3 and 5, the response magnification factor with the effect of the Coriolis force increase by 3.9%, 3.53% and 3.76% respectively compared to the system of non-Coriolis force. In addition, forced response magnification factor of intentionally mistuned bladed disk with and without the Coriolis force under different rotational speed is researched in contrast. It shows that, when the rotational speed is 3000 rpm, the response magnification factor with the Coriolis force increases by 0.65% compared to the system of non-Coriolis force, while the response magnification factor with the Coriolis force decreases by 6.28% compared to the system of non-Coriolis force when the rotational speed is 12000 rpm.

Magnification-temperature correlation: The dark side of integrated Sachs-Wolfe measurements

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

LoVerde, Marilena; Hui, Lam; Gaztanaga, Enrique

2007-02-15

Integrated Sachs-Wolfe (ISW) measurements, which involve cross-correlating the microwave background anisotropies with the foreground large-scale structure (e.g. traced by galaxies/quasars), have proven to be an interesting probe of dark energy. We show that magnification bias, which is the inevitable modulation of the foreground number counts by gravitational lensing, alters both the scale dependence and amplitude of the observed ISW signal. This is true especially at high redshifts because (1) the intrinsic galaxy-temperature signal diminishes greatly back in the matter-dominated era, (2) the lensing efficiency increases with redshift and (3) the number count slope generally steepens with redshift in a magnitudemore » limited sample. At z > or approx. 2, the magnification-temperature correlation dominates over the intrinsic galaxy-temperature correlation and causes the observed ISW signal to increase with redshift, despite dark energy subdominance--a result of the fact that magnification probes structures all the way from the observer to the sources. Ignoring magnification bias therefore can lead to (significantly) erroneous conclusions about dark energy. While the lensing modulation opens up an interesting high z window for ISW measurements, high redshift measurements are not expected to add much new information to low redshift ones if dark energy is indeed the cosmological constant. This is because lensing introduces significant covariance across redshifts. The most compelling reasons for pursuing high redshift ISW measurements are to look for potential surprises such as early dark energy domination or signatures of modified gravity. We conclude with a discussion of existing measurements, the highest redshift of which is at the margin of being sensitive to the magnification effect. We also develop a formalism which might be of more general interest: to predict biases in estimating parameters when certain physical effects are ignored in interpreting

The zoom lens of attention: Simulating shuffled versus normal text reading using the SWIFT model

PubMed Central

Schad, Daniel J.; Engbert, Ralf

2012-01-01

Assumptions on the allocation of attention during reading are crucial for theoretical models of eye guidance. The zoom lens model of attention postulates that attentional deployment can vary from a sharp focus to a broad window. The model is closely related to the foveal load hypothesis, i.e., the assumption that the perceptual span is modulated by the difficulty of the fixated word. However, these important theoretical concepts for cognitive research have not been tested quantitatively in eye movement models. Here we show that the zoom lens model, implemented in the SWIFT model of saccade generation, captures many important patterns of eye movements. We compared the model's performance to experimental data from normal and shuffled text reading. Our results demonstrate that the zoom lens of attention might be an important concept for eye movement control in reading. PMID:22754295

Development of a dry actuation conducting polymer actuator for micro-optical zoom lenses

NASA Astrophysics Data System (ADS)

Kim, Baek-Chul; Kim, Hyunseok; Nguyen, H. C.; Cho, M. S.; Lee, Y.; Nam, Jae-Do; Choi, Hyouk Ryeol; Koo, J. C.; Jeong, H.-S.

2008-03-01

The objective of the present work is to demonstrate the efficiency and feasibility of NBR (Nitrile Butadiene Rubber) based conducting polymer actuator that is fabricated into a micro zoon lens driver. Unlike the traditional conducting polymer that normally operates in a liquid, the proposed actuator successfully provides fairly effective driving performance for the zoom lens system in a dry environment. And this paper is including the experiment results for an efficiency improvement. The result suggested by an experiment was efficient in micro optical zoom lens system. In addition, the developed design method of actuator was given consideration to design the system.

Defocus and magnification dependent variation of TEM image astigmatism.

PubMed

Yan, Rui; Li, Kunpeng; Jiang, Wen

2018-01-10

Daily alignment of the microscope is a prerequisite to reaching optimal lens conditions for high resolution imaging in cryo-EM. In this study, we have investigated how image astigmatism varies with the imaging conditions (e.g. defocus, magnification). We have found that the large change of defocus/magnification between visual correction of astigmatism and subsequent data collection tasks, or during data collection, will inevitably result in undesirable astigmatism in the final images. The dependence of astigmatism on the imaging conditions varies significantly from time to time, so that it cannot be reliably compensated by pre-calibration of the microscope. Based on these findings, we recommend that the same magnification and the median defocus of the intended defocus range for final data collection are used in the objective lens astigmatism correction task during microscope alignment and in the focus mode of the iterative low-dose imaging. It is also desirable to develop a fast, accurate method that can perform dynamic correction of the astigmatism for different intended defocuses during automated imaging. Our findings also suggest that the slope of astigmatism changes caused by varying defocuses can be used as a convenient measurement of objective lens rotation symmetry and potentially an acceptance test of new electron microscopes.

Weak-lensing magnification as a probe for the dark Universe

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

García Fernández, Manuel

This Thesis is devoted to the analysis of weak-lensing magnification on the Dark Energy Survey. Two analysis with different goals each are made on different data-sets: the Science Verification (DES-SV) and the Year 1 (DES-Y1). The DES-SV analysis aims the development of techniques to detect the weak-lensing number count magnification signal and the mitigation of systematic errors. The DES-Y1 analysis employs the methods used with the DES-SV data to measure the convergence profile of the emptiest regions of the Universe –voids and troughs–to use them as a new cosmological probe.

Acceptable distortion and magnification of images on reflective surfaces in an augmented reality system

NASA Astrophysics Data System (ADS)

Yamamoto, Shoji; Hosokawa, Natsumi; Yokoya, Mayu; Tsumura, Norimichi

2016-12-01

In this paper, we investigated the consistency of visual perception for the change of reflection images in an augmented reality setting. Reflection images with distortion and magnification were generated by changing the capture position of the environment map. Observers evaluated the distortion and magnification in reflection images where the reflected objects were arranged symmetrically or asymmetrically. Our results confirmed that the observers' visual perception was more sensitive to changes in distortion than in magnification in the reflection images. Moreover, the asymmetrical arrangement of reflected objects effectively expands the acceptable range of distortion compared with the symmetrical arrangement.

Anisotropic magnification distortion of the 3D galaxy correlation. II. Fourier and redshift space

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

Hui Lam; Department of Physics, Columbia University, New York, New York 10027; Institute of Theoretical Physics, Chinese University of Hong Kong

2008-03-15

In paper I of this series we discuss how magnification bias distorts the 3D correlation function by enhancing the observed correlation in the line-of-sight (LOS) orientation, especially on large scales. This lensing anisotropy is distinctive, making it possible to separately measure the galaxy-galaxy, galaxy-magnification and magnification-magnification correlations. Here we extend the discussion to the power spectrum and also to redshift space. In real space, pairs oriented close to the LOS direction are not protected against nonlinearity even if the pair separation is large; this is because nonlinear fluctuations can enter through gravitational lensing at a small transverse separation (or i.e.more » impact parameter). The situation in Fourier space is different: by focusing on a small wave number k, as is usually done, linearity is guaranteed because both the LOS and transverse wave numbers must be small. This is why magnification distortion of the galaxy correlation appears less severe in Fourier space. Nonetheless, the effect is non-negligible, especially for the transverse Fourier modes, and should be taken into account in interpreting precision measurements of the galaxy power spectrum, for instance those that focus on the baryon oscillations. The lensing induced anisotropy of the power spectrum has a shape that is distinct from the more well-known redshift space anisotropies due to peculiar motions and the Alcock-Paczynski effect. The lensing anisotropy is highly localized in Fourier space while redshift space distortions are more spread out. This means that one could separate the magnification bias component in real observations, implying that potentially it is possible to perform a gravitational lensing measurement without measuring galaxy shapes.« less

Phase-based motion magnification video for monitoring of vital signals using the Hermite transform

NASA Astrophysics Data System (ADS)

Brieva, Jorge; Moya-Albor, Ernesto

2017-11-01

In this paper we present a new Eulerian phase-based motion magnification technique using the Hermite Transform (HT) decomposition that is inspired in the Human Vision System (HVS). We test our method in one sequence of the breathing of a newborn baby and on a video sequence that shows the heartbeat on the wrist. We detect and magnify the heart pulse applying our technique. Our motion magnification approach is compared to the Laplacian phase based approach by means of quantitative metrics (based on the RMS error and the Fourier transform) to measure the quality of both reconstruction and magnification. In addition a noise robustness analysis is performed for the two methods.

Lens models under the microscope: comparison of Hubble Frontier Field cluster magnification maps

NASA Astrophysics Data System (ADS)

Priewe, Jett; Williams, Liliya L. R.; Liesenborgs, Jori; Coe, Dan; Rodney, Steven A.

2017-02-01

Using the power of gravitational lensing magnification by massive galaxy clusters, the Hubble Frontier Fields provide deep views of six patches of the high-redshift Universe. The combination of deep Hubble imaging and exceptional lensing strength has revealed the greatest numbers of multiply-imaged galaxies available to constrain models of cluster mass distributions. However, even with O(100) images per cluster, the uncertainties associated with the reconstructions are not negligible. The goal of this paper is to show the diversity of model magnification predictions. We examine seven and nine mass models of Abell 2744 and MACS J0416, respectively, submitted to the Mikulski Archive for Space Telescopes for public distribution in 2015 September. The dispersion between model predictions increases from 30 per cent at common low magnifications (μ ˜ 2) to 70 per cent at rare high magnifications (μ ˜ 40). MACS J0416 exhibits smaller dispersions than Abell 2744 for 2 < μ < 10. We show that magnification maps based on different lens inversion techniques typically differ from each other by more than their quoted statistical errors. This suggests that some models underestimate the true uncertainties, which are primarily due to various lensing degeneracies. Though the exact mass sheet degeneracy is broken, its generalized counterpart is not broken at least in Abell 2744. Other local degeneracies are also present in both clusters. Our comparison of models is complementary to the comparison of reconstructions of known synthetic mass distributions. By focusing on observed clusters, we can identify those that are best constrained, and therefore provide the clearest view of the distant Universe.

Fast digital zooming system using directionally adaptive image interpolation and restoration.

PubMed

Kang, Wonseok; Jeon, Jaehwan; Yu, Soohwan; Paik, Joonki

2014-01-01

This paper presents a fast digital zooming system for mobile consumer cameras using directionally adaptive image interpolation and restoration methods. The proposed interpolation algorithm performs edge refinement along the initially estimated edge orientation using directionally steerable filters. Either the directionally weighted linear or adaptive cubic-spline interpolation filter is then selectively used according to the refined edge orientation for removing jagged artifacts in the slanted edge region. A novel image restoration algorithm is also presented for removing blurring artifacts caused by the linear or cubic-spline interpolation using the directionally adaptive truncated constrained least squares (TCLS) filter. Both proposed steerable filter-based interpolation and the TCLS-based restoration filters have a finite impulse response (FIR) structure for real time processing in an image signal processing (ISP) chain. Experimental results show that the proposed digital zooming system provides high-quality magnified images with FIR filter-based fast computational structure.

Note: Magnification of a polarization angle with a Littrow layout brazed grating

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

Sasao, H., E-mail: sasao.hajime@jaea.go.jp; Kubo, H.; Kawano, Y.

A new method to magnify a small polarization angle with brazed gratings has been developed. In the method, difference in diffraction efficiency for S and P polarization components is used. The magnification dependence on the incident angle can be small by arranging the grating in Littrow layout. A magnification with a factor ∼2.7 has been demonstrated for a 10.6 μm CO{sub 2} laser beam as expected from a calculation. The method is applicable in many polarimetry fields.

Awareness and attitude toward using dental magnification among dental students and residents at King Abdulaziz University, Faculty of Dentistry.

PubMed

Alhazzazi, Turki Y; Alzebiani, Nouran A; Alotaibi, Samaher K; Bogari, Dania F; Bakalka, Ghaida T; Hazzazi, Loai W; Jan, Ahmed M; McDonald, Neville J

2016-07-19

The authors conducted a study aimed to assess the awareness and attitude among dental students and residents at King Abdulaziz University, Faculty of Dentistry (KAUFD) toward using dental magnification. An e-questionnaire was formulated then sent to dental students and residents (n = 651). The questionnaire included questions that assessed both the awareness and attitude toward using dental magnification. Data were analyzed using IBM SPSS version 22. The chi-square test was used to establish relationships between categorical variables. The response rate was 69.7 % (n = 454). Of those, 78.1 % did not use magnification during dental procedures. However, 81.8 % agreed that dental magnification could enhance the accuracy and quality of their dental work. Thus, 91.6 % thought it would be useful in endodontics and 46.3 % voted for surgery. Of the 21.9 % that used magnification, dental loupes were mostly used, 55.9 %. The majority (59.4 %) of the participants believed that using dental magnification should be introduced by faculty beginning in Year I of dental school. Among our respondents, most of the undergraduate students did not use dental magnification nor attended courses in the use of dental magnifications. However, most of the students were aware of its significance in improving the accuracy and quality of their work.

Cascaded plasmonic superlens for far-field imaging with magnification at visible wavelength.

PubMed

Li, Huiyu; Fu, Liwei; Frenner, Karsten; Osten, Wolfgang

2018-04-16

We experimentally demonstrate a novel design of a cascaded plasmonic superlens, which can directly image subwavelength objects with magnification in the far field at visible wavelengths. The lens consists of two cascaded plasmonic slabs. One is a plasmonic metasurface used for near field coupling, and the other one is a planar plasmonic lens used for phase compensation and thus image magnification. First, we show numerical calculations about the performance of the lens. Based on these results we then describe the fabrication of both sub-structures and their combination. Finally, we demonstrate imaging performance of the lens for a subwavelength double-slit object as an example. The fabricated superlens exhibits a lateral resolution down to 180 nm at a wavelength of 640 nm, as predicted by numerical calculations. This might be the first experimental demonstration in which a planar plasmonic lens is employed for near-field image magnification. Our results could open a way for designing and fabricating novel miniaturized plasmonic superlenses in the future.

Parallel, exhaustive processing underlies logarithmic search functions: Visual search with cortical magnification.

PubMed

Wang, Zhiyuan; Lleras, Alejandro; Buetti, Simona

2018-04-17

Our lab recently found evidence that efficient visual search (with a fixed target) is characterized by logarithmic Reaction Time (RT) × Set Size functions whose steepness is modulated by the similarity between target and distractors. To determine whether this pattern of results was based on low-level visual factors uncontrolled by previous experiments, we minimized the possibility of crowding effects in the display, compensated for the cortical magnification factor by magnifying search items based on their eccentricity, and compared search performance on such displays to performance on displays without magnification compensation. In both cases, the RT × Set Size functions were found to be logarithmic, and the modulation of the log slopes by target-distractor similarity was replicated. Consistent with previous results in the literature, cortical magnification compensation eliminated most target eccentricity effects. We conclude that the log functions and their modulation by target-distractor similarity relations reflect a parallel exhaustive processing architecture for early vision.

Project Zoom IN, Citizen Perspectives on Climate and Water Resources

NASA Astrophysics Data System (ADS)

Glaser, J. P.

2012-12-01

Perspective on climate and water resources can come from the top, scientists sharing invaluable data and findings about how climate dynamics function or quantifications of systems in flux. However, citizens are endowed with an equally as powerful tool for insight: ground zero experience. Project Zoom In is a nascent project undertaken by Global Media Forge to empower youth, educators and scientists with tools to reach the media with locale-specific imagery and perspective of climate dynamics and evidence of anecdotal resource management of liquid gold: fresh water. Zoom In is taking root in Colorado but is designed for national/international scaling. This effort has three limbs: (1) student, scientist and educator workshops teaching invaluable video production skills (2) engaging Colorado school systems to stimulate submission of clips to full video productions to our database, and (3) embedding the findings on a taxonomic GIS interface on-line. The website will be invaluable in classrooms and link network media to individuals with firsthand viewpoints on change.; Climate and Water Resources

MEASURING LENSING MAGNIFICATION OF QUASARS BY LARGE SCALE STRUCTURE USING THE VARIABILITY-LUMINOSITY RELATION

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

Bauer, Anne H.; Seitz, Stella; Jerke, Jonathan

2011-05-10

We introduce a technique to measure gravitational lensing magnification using the variability of type I quasars. Quasars' variability amplitudes and luminosities are tightly correlated, on average. Magnification due to gravitational lensing increases the quasars' apparent luminosity, while leaving the variability amplitude unchanged. Therefore, the mean magnification of an ensemble of quasars can be measured through the mean shift in the variability-luminosity relation. As a proof of principle, we use this technique to measure the magnification of quasars spectroscopically identified in the Sloan Digital Sky Survey (SDSS), due to gravitational lensing by galaxy clusters in the SDSS MaxBCG catalog. The Palomar-QUESTmore » Variability Survey, reduced using the DeepSky pipeline, provides variability data for the sources. We measure the average quasar magnification as a function of scaled distance (r/R{sub 200}) from the nearest cluster; our measurements are consistent with expectations assuming Navarro-Frenk-White cluster profiles, particularly after accounting for the known uncertainty in the clusters' centers. Variability-based lensing measurements are a valuable complement to shape-based techniques because their systematic errors are very different, and also because the variability measurements are amenable to photometric errors of a few percent and to depths seen in current wide-field surveys. Given the volume data of the expected from current and upcoming surveys, this new technique has the potential to be competitive with weak lensing shear measurements of large-scale structure.« less

Hybrid Microscopy: Enabling Inexpensive High-Performance Imaging through Combined Physical and Optical Magnifications.

PubMed

Zhang, Yu Shrike; Chang, Jae-Byum; Alvarez, Mario Moisés; Trujillo-de Santiago, Grissel; Aleman, Julio; Batzaya, Byambaa; Krishnadoss, Vaishali; Ramanujam, Aishwarya Aravamudhan; Kazemzadeh-Narbat, Mehdi; Chen, Fei; Tillberg, Paul W; Dokmeci, Mehmet Remzi; Boyden, Edward S; Khademhosseini, Ali

2016-03-15

To date, much effort has been expended on making high-performance microscopes through better instrumentation. Recently, it was discovered that physical magnification of specimens was possible, through a technique called expansion microscopy (ExM), raising the question of whether physical magnification, coupled to inexpensive optics, could together match the performance of high-end optical equipment, at a tiny fraction of the price. Here we show that such "hybrid microscopy" methods--combining physical and optical magnifications--can indeed achieve high performance at low cost. By physically magnifying objects, then imaging them on cheap miniature fluorescence microscopes ("mini-microscopes"), it is possible to image at a resolution comparable to that previously attainable only with benchtop microscopes that present costs orders of magnitude higher. We believe that this unprecedented hybrid technology that combines expansion microscopy, based on physical magnification, and mini-microscopy, relying on conventional optics--a process we refer to as Expansion Mini-Microscopy (ExMM)--is a highly promising alternative method for performing cost-effective, high-resolution imaging of biological samples. With further advancement of the technology, we believe that ExMM will find widespread applications for high-resolution imaging particularly in research and healthcare scenarios in undeveloped countries or remote places.

Benefit of the UltraZoom beamforming technology in noise in cochlear implant users.

PubMed

Mosnier, Isabelle; Mathias, Nathalie; Flament, Jonathan; Amar, Dorith; Liagre-Callies, Amelie; Borel, Stephanie; Ambert-Dahan, Emmanuèle; Sterkers, Olivier; Bernardeschi, Daniele

2017-09-01

The objectives of the study were to demonstrate the audiological and subjective benefits of the adaptive UltraZoom beamforming technology available in the Naída CI Q70 sound processor, in cochlear-implanted adults upgraded from a previous generation sound processor. Thirty-four adults aged between 21 and 89 years (mean 53 ± 19) were prospectively included. Nine subjects were unilaterally implanted, 11 bilaterally and 14 were bimodal users. The mean duration of cochlear implant use was 7 years (range 5-15 years). Subjects were tested in quiet with monosyllabic words and in noise with the adaptive French Matrix test in the best-aided conditions. The test setup contained a signal source in front of the subject and three noise sources at +/-90° and 180°. The noise was presented at a fixed level of 65 dB SPL and the level of speech signal was varied to obtain the speech reception threshold (SRT). During the upgrade visit, subjects were tested with the Harmony and with the Naída CI sound processors in omnidirectional microphone configuration. After a take-home phase of 2 months, tests were repeated with the Naída CI processor with and without UltraZoom. Subjective assessment of the sound quality in daily environments was recorded using the APHAB questionnaire. No difference in performance was observed in quiet between the two processors. The Matrix test in noise was possible in the 21 subjects with the better performance. No difference was observed between the two processors for performance in noise when using the omnidirectional microphone. At the follow-up session, the median SRT with the Naída CI processor with UltraZoom was -4 dB compared to -0.45 dB without UltraZoom. The use of UltraZoom improved the median SRT by 3.6 dB (p < 0.0001, Wilcoxon paired test). When looking at the APHAB outcome, improvement was observed for speech understanding in noisy environments (p < 0.01) and in aversive situations (p < 0.05) in the group of 21 subjects who were

The effect of magnification lenses on reducing musculoskeletal discomfort among dentists.

PubMed

Aghilinejad, Mashallah; Kabir-Mokamelkhah, Elaheh; Talebi, Atefeh; Soleimani, Roghayeh; Dehghan, Naser

2016-01-01

Background: Work-related musculoskeletal disorders are the most important problems in the health workforce. These discomforts cause many working days losses, increase absenteeism from work, and impose annual economic costs. Awkward posture is the most important factor among the risk factors for work-related musculoskeletal disorders. This study aimed at implementing an interventional ergonomic program to minimize musculoskeletal disorder among dentists. Methods: This semi- experimental study was conducted on 75 dentists of Milad hospital using a census method. The Nordic Questionnaire was used to determine the prevalence of musculoskeletal disorders. In this study, the intervention was to apply optical magnification lens whose impact on reducing musculoskeletal disorder had been previously investigated. Corlett and Bishop Scale was used to evaluate musculoskeletal disorders before and after the intervention. Paired t-test was conducted to compare the discomfort intensity before and after the intervention. Results: The results revealed that the prevalence of musculoskeletal disorders in neck, back, shoulder, and arm were higher than other areas of the body in dentists. There was a significant difference in discomfort intensity of the neck, shoulder, arm, back, elbow, forearm, and the whole body after the ergonomic intervention (p<0.05). Surveys on improving working conditions using the magnification lens revealed that more than 89% of the individuals expressed that the use of the lens increased the ease while working. Conclusion: The present study revealed that the use of optical magnification loupes, because of providing a suitable posture while working, could reduce musculoskeletal disorders in different areas of the body. Thus, we can predict that the prevalence of musculoskeletal disorders will be reduced in dentists in a long run if they use optical magnification loupes.

Magnification of starting torques of dc motors by maximum power point trackers in photovoltaic systems

NASA Technical Reports Server (NTRS)

Appelbaum, J.; Singer, S.

1989-01-01

A calculation of the starting torque ratio of permanent magnet, series, and shunt-excited dc motors powered by solar cell arrays is presented for two cases, i.e., with and without a maximum-power-point tracker (MPPT). Defining motor torque magnification by the ratio of the motor torque with an MPPT to the motor torque without an MPPT, a magnification of 3 for the permanent magnet motor and a magnification of 7 for both the series and shunt motors are obtained. The study also shows that all motor types are less sensitive to solar insolation variation in systems including MPPTs as compared to systems without MPPTs.

Variable Magnification With Kirkpatrick-Baez Optics for Synchrotron X-Ray Microscopy

PubMed Central

Jach, Terrence; Bakulin, Alex S.; Durbin, Stephen M.; Pedulla, Joseph; Macrander, Albert

2006-01-01

We describe the distinction between the operation of a short focal length x-ray microscope forming a real image with a laboratory source (convergent illumination) and with a highly collimated intense beam from a synchrotron light source (Köhler illumination). We demonstrate the distinction with a Kirkpatrick-Baez microscope consisting of short focal length multilayer mirrors operating at an energy of 8 keV. In addition to realizing improvements in the resolution of the optics, the synchrotron radiation microscope is not limited to the usual single magnification at a fixed image plane. Higher magnification images are produced by projection in the limit of geometrical optics with a collimated beam. However, in distinction to the common method of placing the sample behind the optical source of a diverging beam, we describe the situation in which the sample is located in the collimated beam before the optical element. The ultimate limits of this magnification result from diffraction by the specimen and are determined by the sample position relative to the focal point of the optic. We present criteria by which the diffraction is minimized. PMID:27274930

Slit-lamp photography and videography with high magnifications

PubMed Central

Yuan, Jin; Jiang, Hong; Mao, Xinjie; Ke, Bilian; Yan, Wentao; Liu, Che; Cintrón-Colón, Hector R; Perez, Victor L; Wang, Jianhua

2015-01-01

Purpose To demonstrate the use of the slit-lamp photography and videography with extremely high magnifications for visualizing structures of the anterior segment of the eye. Methods A Canon 60D digital camera with Movie Crop Function was adapted into a Nikon FS-2 slit-lamp to capture still images and video clips of the structures of the anterior segment of the eye. Images obtained using the slit-lamp were tested for spatial resolution. The cornea of human eyes was imaged with the slit-lamp and the structures were compared with the pictures captured using the ultra-high resolution optical coherence tomography (UHR-OCT). The central thickness of the corneal epithelium and total cornea was obtained using the slit-lamp and the results were compared with the thickness obtained using UHR-OCT. Results High-quality ocular images and higher spatial resolutions were obtained by using the slit-lamp with extremely high magnifications and Movie Crop Function, rather than the traditional slit-lamp. The structures and characteristics of the cornea, such as the normal epithelium, abnormal epithelium of corneal intraepithelial neoplasia, LASIK interface, and contact lenses, were clearly visualized using this device. These features were confirmed by comparing the obtained images with those acquired using UHR-OCT. Moreover, the tear film debris on the ocular surface and the corneal nerve in the anterior corneal stroma were also visualized. The thicknesses of the corneal epithelium and total cornea were similar to that measured using UHR-OCT (P < 0.05). Conclusions We demonstrated that the slit-lamp photography and videography with extremely high magnifications allows better visualization of the anterior segment structures of the eye, especially of the epithelium, when compared with the traditional slit-lamp. PMID:26020484

Zoom-in on Epimetheus

NASA Image and Video Library

2017-07-03

This zoomed-in view of Epimetheus, one of the highest resolution ever taken, shows a surface covered in craters, vivid reminders of the hazards of space. Epimetheus (70 miles or 113 kilometers across) is too small for its gravity to hold onto an atmosphere. It is also too small to be geologically active. There is therefore no way to erase the scars from meteor impacts, except for the generation of new impact craters on top of old ones. This view looks toward anti-Saturn side of Epimetheus. North on Epimetheus is up and rotated 32 degrees to the right. The image was taken with the Cassini spacecraft narrow-angle camera on Feb. 21, 2017 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 939 nanometers. The view was acquired at a distance of approximately 9,300 miles (15,000 kilometers) from Epimetheus and at a Sun-Epimetheus-spacecraft, or phase, angle of 71 degrees. Image scale is 290 feet (89 meters) per pixel. https://photojournal.jpl.nasa.gov/catalog/PIA21335

Numerical Zooming Between a NPSS Engine System Simulation and a One-Dimensional High Compressor Analysis Code

NASA Technical Reports Server (NTRS)

Follen, Gregory; auBuchon, M.

2000-01-01

Within NASA's High Performance Computing and Communication (HPCC) program, NASA Glenn Research Center is developing an environment for the analysis/design of aircraft engines called the Numerical Propulsion System Simulation (NPSS). NPSS focuses on the integration of multiple disciplines such as aerodynamics, structures, and heat transfer along with the concept of numerical zooming between zero-dimensional to one-, two-, and three-dimensional component engine codes. In addition, the NPSS is refining the computing and communication technologies necessary to capture complex physical processes in a timely and cost-effective manner. The vision for NPSS is to create a "numerical test cell" enabling full engine simulations overnight on cost-effective computing platforms. Of the different technology areas that contribute to the development of the NPSS Environment, the subject of this paper is a discussion on numerical zooming between a NPSS engine simulation and higher fidelity representations of the engine components (fan, compressor, burner, turbines, etc.). What follows is a description of successfully zooming one-dimensional (row-by-row) high-pressure compressor analysis results back to a zero-dimensional NPSS engine simulation and a discussion of the results illustrated using an advanced data visualization tool. This type of high fidelity system-level analysis, made possible by the zooming capability of the NPSS, will greatly improve the capability of the engine system simulation and increase the level of virtual test conducted prior to committing the design to hardware.

Radiation dose and magnification in pelvic X-ray: EOS™ imaging system versus plain radiographs.

PubMed

Chiron, P; Demoulin, L; Wytrykowski, K; Cavaignac, E; Reina, N; Murgier, J

2017-12-01

In plain pelvic X-ray, magnification makes measurement unreliable. The EOS™ (EOS Imaging, Paris France) imaging system is reputed to reproduce patient anatomy exactly, with a lower radiation dose. This, however, has not been assessed according to patient weight, although both magnification and irradiation are known to vary with weight. We therefore conducted a prospective comparative study, to compare: (1) image magnification and (2) radiation dose between the EOS imaging system and plain X-ray. The EOS imaging system reproduces patient anatomy exactly, regardless of weight, unlike plain X-ray. A single-center comparative study of plain pelvic X-ray and 2D EOS radiography was performed in 183 patients: 186 arthroplasties; 104 male, 81 female; mean age 61.3±13.7years (range, 24-87years). Magnification and radiation dose (dose-area product [DAP]) were compared between the two systems in 186 hips in patients with a mean body-mass index (BMI) of 27.1±5.3kg/m 2 (range, 17.6-42.3kg/m 2 ), including 7 with morbid obesity. Mean magnification was zero using the EOS system, regardless of patient weight, compared to 1.15±0.05 (range, 1-1.32) on plain X-ray (P<10 -5 ). In patients with BMI<25, mean magnification on plain X-ray was 1.15±0.05 (range, 1-1.25) and, in patients with morbid obesity, 1.22±0.06 (range, 1.18-1.32). The mean radiation dose was 8.19±2.63dGy/cm 2 (range, 1.77-14.24) with the EOS system, versus 19.38±12.37dGy/cm 2 (range, 4.77-81.75) with plain X-ray (P<10 -4 ). For BMI >40, mean radiation dose was 9.36±2.57dGy/cm 2 (range, 7.4-14.2) with the EOS system, versus 44.76±22.21 (range, 25.2-81.7) with plain X-ray. Radiation dose increased by 0.20dGy with each extra BMI point for the EOS system, versus 0.74dGy for plain X-ray. Magnification did not vary with patient weight using the EOS system, unlike plain X-ray, and radiation dose was 2.5-fold lower. 3, prospective case-control study. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Engineering web maps with gradual content zoom based on streaming vector data

NASA Astrophysics Data System (ADS)

Huang, Lina; Meijers, Martijn; Šuba, Radan; van Oosterom, Peter

2016-04-01

Vario-scale data structures have been designed to support gradual content zoom and the progressive transfer of vector data, for use with arbitrary map scales. The focus to date has been on the server side, especially on how to convert geographic data into the proposed vario-scale structures by means of automated generalisation. This paper contributes to the ongoing vario-scale research by focusing on the client side and communication, particularly on how this works in a web-services setting. It is claimed that these functionalities are urgently needed, as many web-based applications, both desktop and mobile, require gradual content zoom, progressive transfer and a high performance level. The web-client prototypes developed in this paper make it possible to assess the behaviour of vario-scale data and to determine how users will actually see the interactions. Several different options of web-services communication architectures are possible in a vario-scale setting. These options are analysed and tested with various web-client prototypes, with respect to functionality, ease of implementation and performance (amount of transmitted data and response times). We show that the vario-scale data structure can fit in with current web-based architectures and efforts to standardise map distribution on the internet. However, to maximise the benefits of vario-scale data, a client needs to be aware of this structure. When a client needs a map to be refined (by means of a gradual content zoom operation), only the 'missing' data will be requested. This data will be sent incrementally to the client from a server. In this way, the amount of data transferred at one time is reduced, shortening the transmission time. In addition to these conceptual architecture aspects, there are many implementation and tooling design decisions at play. These will also be elaborated on in this paper. Based on the experiments conducted, we conclude that the vario-scale approach indeed supports gradual

Variable magnification glancing incidence x ray telescope

NASA Technical Reports Server (NTRS)

Hoover, Richard (Inventor)

1990-01-01

A multispectral glancing incidence x ray telescope is disclosed, which capable of broadband, high resolution imaging of solar and stellar x ray and extreme ultraviolet radiation sources includes a primary optical system which focuses the incoming radiation to a primary focus. Two or more ellipsoidal mirrors are positioned behind the primary focus at an inclination to the optical axis, each mirror having a concave surface coated with a multilayer synthetic microstructure coating to reflect a desired wavelength. The ellipsoidal mirrors are segments of respective ellipsoids having a common first focus coincident with the primary focus. A detector such as an x ray sensitive photographic film is positioned at the second focus of each of the ellipsoids so that each of the ellipsoidal mirrors may reflect the image at the first focus to the detector. In one embodiment the mirrors are inclined at different angles and has its respective second focus at a different location, separate detectors being located at the respective second focus. The mirrors are arranged so that the magnification and field of view differ, and a solenoid activated arm may withdraw at least one mirror from the beam to select the mirror upon which the beam is to impinge so that selected magnifications and fields of view may be detected.

Detecting imperceptible movements in structures by means of video magnification

NASA Astrophysics Data System (ADS)

Ordóñez, Celestino; Cabo, Carlos; García-Cortés, Silverio; Menéndez, Agustín.

2017-06-01

The naked eye is not able to perceive very slow movements such as those occurring in certain structures under external forces. This might be the case of metallic or concrete bridges, tower cranes or steel beams. However, sometimes it is of interest to view such movements, since they can provide useful information regarding the mechanical state of those structures. In this work, we analyze the utility of video magnification to detect imperceptible movements in several types of structures. First, laboratory experiments were conducted to validate the method. Then, two different tests were carried out on real structures: one on a water slide and another on a tower crane. The results obtained allow us to conclude that image cross-correlation and video magnification is indeed a promising low-cost technique for structure health monitoring.

Optical configuration with fixed transverse magnification for self-interference incoherent digital holography.

PubMed

Imbe, Masatoshi

2018-03-20

The optical configuration proposed in this paper consists of a 4-f optical setup with the wavefront modulation device on the Fourier plane, such as a concave mirror and a spatial light modulator. The transverse magnification of reconstructed images with the proposed configuration is independent of locations of an object and an image sensor; therefore, reconstructed images of object(s) at different distances can be scaled with a fixed transverse magnification. It is yielded based on Fourier optics and mathematically verified with the optical matrix method. Numerical simulation results and experimental results are also given to confirm the fixity of the reconstructed images.

Submillimeter Galaxy Number Counts and Magnification by Galaxy Clusters

NASA Astrophysics Data System (ADS)

Lima, Marcos; Jain, Bhuvnesh; Devlin, Mark; Aguirre, James

2010-07-01

We present an analytical model that reproduces measured galaxy number counts from surveys in the wavelength range of 500 μm-2 mm. The model involves a single high-redshift galaxy population with a Schechter luminosity function that has been gravitationally lensed by galaxy clusters in the mass range 1013-1015 M sun. This simple model reproduces both the low-flux and the high-flux end of the number counts reported by the BLAST, SCUBA, AzTEC, and South Pole Telescope (SPT) surveys. In particular, our model accounts for the most luminous galaxies detected by SPT as the result of high magnifications by galaxy clusters (magnification factors of 10-30). This interpretation implies that submillimeter (submm) and millimeter surveys of this population may prove to be a useful addition to ongoing cluster detection surveys. The model also implies that the bulk of submm galaxies detected at wavelengths larger than 500 μm lie at redshifts greater than 2.

ZOOM: a generic personal computer-based teaching program for public health and its application in schistosomiasis control.

PubMed Central

Martin, G. T.; Yoon, S. S.; Mott, K. E.

1991-01-01

Schistosomiasis, a group of parasitic diseases caused by Schistosoma parasites, is associated with water resources development and affects more than 200 million people in 76 countries. Depending on the species of parasite involved, disease of the liver, spleen, gastrointestinal or urinary tract, or kidneys may result. A computer-assisted teaching package has been developed by WHO for use in the training of public health workers involved in schistosomiasis control. The package consists of the software, ZOOM, and a schistosomiasis information file, Dr Schisto, and uses hypermedia technology to link pictures and text. ZOOM runs on the IBM-PC and IBM-compatible computers, is user-friendly, requires a minimal hardware configuration, and can interact with the user in English, French, Spanish or Portuguese. The information files for ZOOM can be created or modified by the instructor using a word processor, and thus can be designed to suit the need of students. No programming knowledge is required to create the stacks. PMID:1786618

Zoom-climb altitude maximization of the F-4C and F-15 aircraft for stratospheric sampling missions

NASA Technical Reports Server (NTRS)

Hague, D. S.; Merz, A. W.; Page, W. A.

1976-01-01

Some predictions indicate that byproducts of aerosol containers may lead to a modification of the ultraviolet-radiation shielding properties of the upper atmosphere. NASA currently monitors atmospheric properties to 70,000 feet using U-2 aircraft. Testing is needed at about 100,000 feet for adequate monitoring of possible aerosol contaminants during the next decade. To study this problem the F-4C and F-15 aircraft were analyzed to determine their maximum altitude ability in zoom-climb maneuvers. These trajectories must satisfy realistic dynamic pressure and Mach number constraints. Maximum altitudes obtained for the F4-C are above 90,000 feet, and for the F-15 above 100,000 feet. Sensitivities of the zoom-climb altitudes were found with respect to several variables including vehicle thrust, initial weight, stratospheric winds and the constraints. A final decision on aircraft selection must be based on mission modification costs and operational considerations balanced against their respective zoom altitude performance capabilities.

Ribosomal DNA Organization Before and After Magnification in Drosophila melanogaster

PubMed Central

Bianciardi, Alessio; Boschi, Manuela; Swanson, Ellen E.; Belloni, Massimo; Robbins, Leonard G.

2012-01-01

In all eukaryotes, the ribosomal RNA genes are stably inherited redundant elements. In Drosophila melanogaster, the presence of a Ybb− chromosome in males, or the maternal presence of the Ribosomal exchange (Rex) element, induces magnification: a heritable increase of rDNA copy number. To date, several alternative classes of mechanisms have been proposed for magnification: in situ replication or extra-chromosomal replication, either of which might act on short or extended strings of rDNA units, or unequal sister chromatid exchange. To eliminate some of these hypotheses, none of which has been clearly proven, we examined molecular-variant composition and compared genetic maps of the rDNA in the bb2 mutant and in some magnified bb+ alleles. The genetic markers used are molecular-length variants of IGS sequences and of R1 and R2 mobile elements present in many 28S sequences. Direct comparison of PCR products does not reveal any particularly intensified electrophoretic bands in magnified alleles compared to the nonmagnified bb2 allele. Hence, the increase of rDNA copy number is diluted among multiple variants. We can therefore reject mechanisms of magnification based on multiple rounds of replication of short strings. Moreover, we find no changes of marker order when pre- and postmagnification maps are compared. Thus, we can further restrict the possible mechanisms to two: replication in situ of an extended string of rDNA units or unequal exchange between sister chromatids. PMID:22505623

Lens models and magnification maps of the six Hubble Frontier Fields clusters

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

Johnson, Traci L.; Sharon, Keren; Bayliss, Matthew B.

2014-12-10

We present strong-lensing models as well as mass and magnification maps for the cores of the six Hubble Space Telescope (HST) Frontier Fields galaxy clusters. Our parametric lens models are constrained by the locations and redshifts of multiple image systems of lensed background galaxies. We use a combination of photometric redshifts and spectroscopic redshifts of the lensed background sources obtained by us (for A2744 and AS1063), collected from the literature, or kindly provided by the lensing community. Using our results, we (1) compare the derived mass distribution of each cluster to its light distribution, (2) quantify the cumulative magnification powermore » of the HST Frontier Fields clusters, (3) describe how our models can be used to estimate the magnification and image multiplicity of lensed background sources at all redshifts and at any position within the cluster cores, and (4) discuss systematic effects and caveats resulting from our modeling methods. We specifically investigate the effect of the use of spectroscopic and photometric redshift constraints on the uncertainties of the resulting models. We find that the photometric redshift estimates of lensed galaxies are generally in excellent agreement with spectroscopic redshifts, where available. However, the flexibility associated with relaxed redshift priors may cause the complexity of large-scale structure that is needed to account for the lensing signal to be underestimated. Our findings thus underline the importance of spectroscopic arc redshifts, or tight photometric redshift constraints, for high precision lens models. All products from our best-fit lens models (magnification, convergence, shear, deflection field) and model simulations for estimating errors are made available via the Mikulski Archive for Space Telescopes.« less

Magnification of photometric LRGs by foreground LRGs and clusters in the Sloan Digital Sky Survey

NASA Astrophysics Data System (ADS)

Bauer, Anne H.; Gaztañaga, Enrique; Martí, Pol; Miquel, Ramon

2014-06-01

The magnification effect of gravitational lensing is a powerful probe of the distribution of matter in the universe, yet it is frequently overlooked due to the fact that its signal-to-noise ratio is smaller than that of lensing shear. Because its systematic errors are quite different from those of shear, magnification is nevertheless an important approach with which to study the distribution of large-scale structure. We present lensing mass profiles of spectroscopic luminous red galaxies (LRGs) and galaxy clusters determined through measurements of the weak lensing magnification of photometric LRGs in their background. We measure the change in detected galaxy counts as well as the increased average galaxy flux behind the lenses. In addition, we examine the average change in source colour due to extinction by dust in the lenses. By simultaneously fitting these three probes we constrain the mass profiles and dust-to-mass ratios of the lenses in six bins of lens richness. For each richness bin we fit a Navarro-Frenk-White halo mass, brightest cluster galaxy mass, second halo term, and dust-to-mass ratio. The resulting mass-richness relation is consistent with previous analyses of the catalogues, and limits on the dust-to-mass ratio in the lenses are in agreement with expectations. We explore the effects of including the (low signal-to-noise ratio) flux magnification and reddening measurements in the analysis compared to using only the counts magnification data; the additional probes significantly improve the agreement between our measured mass-richness relation and previous results.

Usage of Accessibility Options for the iPhone and iPad in a Visually Impaired Population.

PubMed

Robinson, Joshua L; Braimah Avery, Vanessa; Chun, Rob; Pusateri, Gregg; Jay, Walter M

2017-01-01

The iPad and iPhone have a number of low-vision accessibility features including Siri Voice Assistant, Large Text, Zoom Magnification, Invert Colors, Voice Over, and Speech Selection. We studied their usage within a low-vision population. Patients were recruited to participate in an IRB-approved survey regarding their usage of the iPad and/or iPhone. Participants met one of the following criteria: best corrected visual acuity (BCVA) of 20/60 or worse, or significant peripheral visual field defects. Thirty-three low-vision patients agreed to participate (mean age 54.3 years). There were 18 different diagnoses represented and the average visual acuity of respondents was 20/119 in the right eye and 20/133 in the left eye. The most commonly used vision accessibility features were Zoom Magnification and Large Text. Although many patients are using the low-vision accessibility features, few are receiving training or recommendations from their eye care specialist.

Galactic Distribution of Planets From High-Magnification Microlensing Events

NASA Astrophysics Data System (ADS)

Gould, Andrew; Yee, Jennifer; Carey, Sean

2015-10-01

We will use Spitzer to measure microlens parallaxes for ~14 microlensing events that are high-magnification (as seen from Earth), in order to determine the Galactic distribution of planets. Simultaneous observations from Spitzer and Earth yield parallaxes because they are separated by ~1 AU, which is of order the size of the Einstein radius projected on the observer plane. Hence, Earth and Spitzer see substantially different lightcurves for the same event. These Spitzer parallaxes enable measurements of the distances to the lenses (and their masses), which is a crucial element for measuring the Galactic distribution of planets. High-mag events are exceptionally sensitive to planets: Gould+ (2010) detected 6 planets from 13 high-mag events. However, previously it was believed impossible to measure their parallaxes using Spitzer: scheduling constraints imply a 3-10 day delay from event recognition to first observation, while high-mag events are typically recognized only 1-2 days before peak. By combining aggressive observing protocols, a completely new photometry pipeline, and new mathematical techniques, we successfully measured parallaxes for 7 events with peak magnification A>100 and another ~7 with 50magnification). These ~4 planets represent significant progress toward the ~12 necessary to measure the Galactic distribution. All lightcurves will be reduced using our customized software and then made public (unrestricted use), within 2 months of the completion of observations (as we did for our 2015 observations).

SUBMILLIMETER GALAXY NUMBER COUNTS AND MAGNIFICATION BY GALAXY CLUSTERS

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

Lima, Marcos; Jain, Bhuvnesh; Devlin, Mark

2010-07-01

We present an analytical model that reproduces measured galaxy number counts from surveys in the wavelength range of 500 {mu}m-2 mm. The model involves a single high-redshift galaxy population with a Schechter luminosity function that has been gravitationally lensed by galaxy clusters in the mass range 10{sup 13}-10{sup 15} M{sub sun}. This simple model reproduces both the low-flux and the high-flux end of the number counts reported by the BLAST, SCUBA, AzTEC, and South Pole Telescope (SPT) surveys. In particular, our model accounts for the most luminous galaxies detected by SPT as the result of high magnifications by galaxy clustersmore » (magnification factors of 10-30). This interpretation implies that submillimeter (submm) and millimeter surveys of this population may prove to be a useful addition to ongoing cluster detection surveys. The model also implies that the bulk of submm galaxies detected at wavelengths larger than 500 {mu}m lie at redshifts greater than 2.« less

The Jordy Electronic Magnification Device: Opinions, Observations, and Commentary

ERIC Educational Resources Information Center

Francis, Barry

2005-01-01

The Jordy electronic magnification device is one of a small number of electronic headborne devices designed to provide people with low vision the capability to perform near-range, intermediate-range, and distance viewing tasks. This report seeks to define the benefits of using the Jordy as a low vision device by people who are legally blind. The…

Influence of Clinical Factors and Magnification Correction on Normal Thickness Profiles of Macular Retinal Layers Using Optical Coherence Tomography.

PubMed

Higashide, Tomomi; Ohkubo, Shinji; Hangai, Masanori; Ito, Yasuki; Shimada, Noriaki; Ohno-Matsui, Kyoko; Terasaki, Hiroko; Sugiyama, Kazuhisa; Chew, Paul; Li, Kenneth K W; Yoshimura, Nagahisa

2016-01-01

To identify the factors which significantly contribute to the thickness variabilities in macular retinal layers measured by optical coherence tomography with or without magnification correction of analytical areas in normal subjects. The thickness of retinal layers {retinal nerve fiber layer (RNFL), ganglion cell layer plus inner plexiform layer (GCLIPL), RNFL plus GCLIPL (ganglion cell complex, GCC), total retina, total retina minus GCC (outer retina)} were measured by macular scans (RS-3000, NIDEK) in 202 eyes of 202 normal Asian subjects aged 20 to 60 years. The analytical areas were defined by three concentric circles (1-, 3- and 6-mm nominal diameters) with or without magnification correction. For each layer thickness, a semipartial correlation (sr) was calculated for explanatory variables including age, gender, axial length, corneal curvature, and signal strength index. Outer retinal thickness was significantly thinner in females than in males (sr2, 0.07 to 0.13) regardless of analytical areas or magnification correction. Without magnification correction, axial length had a significant positive sr with RNFL (sr2, 0.12 to 0.33) and a negative sr with GCLIPL (sr2, 0.22 to 0.31), GCC (sr2, 0.03 to 0.17), total retina (sr2, 0.07 to 0.17) and outer retina (sr2, 0.16 to 0.29) in multiple analytical areas. The significant sr in RNFL, GCLIPL and GCC became mostly insignificant following magnification correction. The strong correlation between the thickness of inner retinal layers and axial length appeared to result from magnification effects. Outer retinal thickness may differ by gender and axial length independently of magnification correction.

Influence of Clinical Factors and Magnification Correction on Normal Thickness Profiles of Macular Retinal Layers Using Optical Coherence Tomography

PubMed Central

Higashide, Tomomi; Ohkubo, Shinji; Hangai, Masanori; Ito, Yasuki; Shimada, Noriaki; Ohno-Matsui, Kyoko; Terasaki, Hiroko; Sugiyama, Kazuhisa; Chew, Paul; Li, Kenneth K. W.; Yoshimura, Nagahisa

2016-01-01

Purpose To identify the factors which significantly contribute to the thickness variabilities in macular retinal layers measured by optical coherence tomography with or without magnification correction of analytical areas in normal subjects. Methods The thickness of retinal layers {retinal nerve fiber layer (RNFL), ganglion cell layer plus inner plexiform layer (GCLIPL), RNFL plus GCLIPL (ganglion cell complex, GCC), total retina, total retina minus GCC (outer retina)} were measured by macular scans (RS-3000, NIDEK) in 202 eyes of 202 normal Asian subjects aged 20 to 60 years. The analytical areas were defined by three concentric circles (1-, 3- and 6-mm nominal diameters) with or without magnification correction. For each layer thickness, a semipartial correlation (sr) was calculated for explanatory variables including age, gender, axial length, corneal curvature, and signal strength index. Results Outer retinal thickness was significantly thinner in females than in males (sr2, 0.07 to 0.13) regardless of analytical areas or magnification correction. Without magnification correction, axial length had a significant positive sr with RNFL (sr2, 0.12 to 0.33) and a negative sr with GCLIPL (sr2, 0.22 to 0.31), GCC (sr2, 0.03 to 0.17), total retina (sr2, 0.07 to 0.17) and outer retina (sr2, 0.16 to 0.29) in multiple analytical areas. The significant sr in RNFL, GCLIPL and GCC became mostly insignificant following magnification correction. Conclusions The strong correlation between the thickness of inner retinal layers and axial length appeared to result from magnification effects. Outer retinal thickness may differ by gender and axial length independently of magnification correction. PMID:26814541

Monte Carlo generated conversion factors for the estimation of average glandular dose in contact and magnification mammography

NASA Astrophysics Data System (ADS)

Koutalonis, M.; Delis, H.; Spyrou, G.; Costaridou, L.; Tzanakos, G.; Panayiotakis, G.

2006-11-01

Magnification mammography is a special technique used in the cases where breast complaints are noted by a woman or when an abnormality is found in a screening mammogram. The carcinogenic risk in mammography is related to the dose deposited in the glandular tissue of the breast rather than the adipose, and average glandular dose (AGD) is the quantity taken into consideration during a mammographic examination. Direct measurement of the AGD is not feasible during clinical practice and thus, the incident air KERMA on the breast surface is used to estimate the glandular dose, with the help of proper conversion factors. Additional conversion factors adapted for magnification and tube voltage are calculated, using Monte Carlo simulation. The effect of magnification degree, tube voltage, various anode/filter material combinations and glandularity on AGD is also studied, considering partial breast irradiation. Results demonstrate that the estimation of AGD utilizing conversion factors depends on these parameters, while the omission of correction factors for magnification and tube voltage can lead to significant underestimation or overestimation of AGD. AGD was found to increase with filter material's k-absorption edge, anode material's k-emission edge, tube voltage and magnification. Decrease of the glandularity of the breast leads to higher AGD due to the increased penetrating ability of the photon beam in thick breasts with low glandularity.

Multispectral variable magnification glancing incidence x ray telescope

NASA Technical Reports Server (NTRS)

Hoover, Richard B. (Inventor)

1992-01-01

A multispectral, variable magnification, glancing incidence, x-ray telescope capable of broadband, high resolution imaging of solar and stellar x-ray and extreme ultraviolet radiation sources is discussed. The telescope includes a primary optical system which focuses the incoming radiation to a primary focus. Two or more rotatable mirror carriers, each providing a different magnification, are positioned behind the primary focus at an inclination to the optical axis. Each carrier has a series of ellipsoidal mirrors, and each mirror has a concave surface covered with a multilayer (layered synthetic microstructure) coating to reflect a different desired wavelength. The mirrors of both carriers are segments of ellipsoids having a common first focus coincident with the primary focus. A detector such as an x-ray sensitive photographic film is positioned at the second respective focus of each mirror so that each mirror may reflect the image at the first focus to the detector at the second focus. The carriers are selectively rotated to position a selected mirror for receiving radiation from the primary optical system, and at least the first carrier may be withdrawn from the path of the radiation to permit a selected mirror on the second carrier to receive the radiation.

Postural Assessment of Students Evaluating the Need of Ergonomic Seat and Magnification in Dentistry.

PubMed

Dable, Rajani A; Wasnik, Pradnya B; Yeshwante, Babita J; Musani, Smita I; Patil, Ashishkumar K; Nagmode, Sunilkumar N

2014-12-01

Dental students using conventional chairs need immediate change in their posture. Implementing an ergonomic posture is necessary as they are at high risk for developing musculoskeletal disorders. This study recommends the use of an ergonomic seat and magnification system to enhance the visibility and the posture of an operator. The aim of this study is to make a foray into the hazards caused by inappropriate posture of dental students while working. It also aims at creating a cognizance about the related health implications among the dental fraternity at large, and to understand the significance of adopting an ergonomic posture since the beginning of the professional course. In the present study, postures have been assessed by using rapid upper limb assessment (RULA). This method uses diagrams of body postures and three scoring tables to evaluate ones exposure to risk factors. Ninety students from II BDS (preclinical students in the second year of dental school) were assessed in three groups using three different seats with and without magnification system. The results recorded significantly higher RULA scores for the conventional seats without using the magnification system compared to the SSC (Salli Saddle Chair-an ergonomic seat) with the use of magnification system. A poor ergonomic posture can make the dental students get habituated to the wrong working style which might lead to MSDs (Musculoskeletal diseases). It is advisable to acclimatize to good habits at the inception of the course, to prevent MSDs later in life.

Optical Magnification Should Be Mandatory for Microsurgery: Scientific Basis and Clinical Data Contributing to Quality Assurance

PubMed Central

Schoeffl, Harald; Lazzeri, Davide; Schnelzer, Richard; Froschauer, Stefan M.

2013-01-01

Background Microsurgical techniques are considered standard procedures in reconstructive surgery. Although microsurgery by itself is defined as surgery aided by optical magnification, there are no guidelines for determining in which clinical situations a microscope or loupe should be used. Therefore, we conducted standardized experiments to objectively assess the impact of optical magnification in microsurgery. Methods Sixteen participants of microsurgical training courses had to complete 2 sets of experiments. Each set had to be performed with an unaided eye, surgical loupes, and a regular operating microscope. The first set of experiments included coaptation of a chicken femoral nerve, and the second set consisted of anastomosing porcine coronary arteries. Evaluation of the sutured nerves and vessels were performed by 2 experienced microsurgeons using an operating microscope. Results The 16 participants of the study completed all of the experiments. The nerve coaptation and vascular anastomoses exercises showed a direct relationship of error frequency and lower optical magnification, meaning that the highest number of microsurgical errors occurred with the unaided eye. For nerve coaptation, there was a strong relationship (P<0.05) between the number of mistakes and magnification, and this relationship was very strong (P<0.01) for vascular anastomoses. Conclusions We were able to prove that microsurgical success is directly related to optical magnification. The human eye's ability to discriminate potentially important anatomical structures is limited, which might be detrimental for clinical results. Although not legally mandatory, surgeries such as reparative surgery after hand trauma should be conducted with magnifying devices for achieving optimal patient outcomes. PMID:23532716

Detection of enhancement in number densities of background galaxies due to magnification by massive galaxy clusters

DOE PAGES

Chiu, I.; Dietrich, J. P.; Mohr, J.; ...

2016-02-18

We present a detection of the enhancement in the number densities of background galaxies induced from lensing magnification and use it to test the Sunyaev-Zel'dovich effect (SZE) inferred masses in a sample of 19 galaxy clusters with median redshift z≃0.42 selected from the South Pole Telescope SPT-SZ survey. Two background galaxy populations are selected for this study through their photometric colours; they have median redshifts z median≃0.9 (low-z background) and z median≃1.8 (high-z background). Stacking these populations, we detect the magnification bias effect at 3.3σ and 1.3σ for the low- and high-z backgrounds, respectively. We fit NFW models simultaneously tomore » all observed magnification bias profiles to estimate the multiplicative factor η that describes the ratio of the weak lensing mass to the mass inferred from the SZE observable-mass relation. We further quantify systematic uncertainties in η resulting from the photometric noise and bias, the cluster galaxy contamination and the estimations of the background properties. The resulting η for the combined background populations with 1σ uncertainties is 0.83 ± 0.24(stat) ± 0.074(sys), indicating good consistency between the lensing and the SZE-inferred masses. We also use our best-fit η to predict the weak lensing shear profiles and compare these predictions with observations, showing agreement between the magnification and shear mass constraints. Our work demonstrates the promise of using the magnification as a complementary method to estimate cluster masses in large surveys.« less

Using motion capture technology to measure the effects of magnification loupes on dental operator posture: A pilot study.

PubMed

Branson, B G; Abnos, R M; Simmer-Beck, M L; King, G W; Siddicky, S F

2018-01-01

Motion analysis has great potential for quantitatively evaluating dental operator posture and the impact of interventions such as magnification loupes on posture and subsequent development of musculoskeletal disorders. This study sought to determine the feasibility of motion capture technology for measurement of dental operator posture and examine the impact that different styles of magnification loupes had on dental operator posture. Forward and lateral head flexion were measured for two different operators while completing a periodontal probing procedure. Each was measured while wearing magnification loupes (flip up-FL and through the lens-TTL) and basic safety lenses. Operators both exhibited reduced forward flexion range of motion (ROM) when using loupes (TTL or FL) compared to a baseline lens (BL). In contrast to forward flexion, no consistent trends were observed for lateral flexion between subjects. The researchers can report that it is possible to measure dental operator posture using motion capture technology. More study is needed to determine which type of magnification loupes (FL or TTL) are superior in improving dental operator posture. Some evidence was found supporting that the quality of operator posture may more likely be related to the use of magnification loupes, rather than the specific type of lenses worn.

Comparison of the diagnostic ability of blue laser imaging magnification versus pit pattern analysis for colorectal polyps.

PubMed

Nakano, Arihiro; Hirooka, Yoshiki; Yamamura, Takeshi; Watanabe, Osamu; Nakamura, Masanao; Funasaka, Kohei; Ohno, Eizaburo; Kawashima, Hiroki; Miyahara, Ryoji; Goto, Hidemi

2017-04-01

Background and study aims  There have been few evaluations of the diagnostic ability of new narrow band light observation blue laser imaging (BLI). The present prospective study compared the diagnostic ability of BLI magnification and pit pattern analysis for colorectal polyps. Patients and methods  We collected lesions prospectively, and the analysis of images was made by two endoscopists, retrospectively. A total of 799 colorectal polyps were examined by BLI magnification and pit pattern analysis at Nagoya University Hospital. The Hiroshima narrow-band imaging classification was used for BLI. Differentiation of neoplastic from non-neoplastic lesions and diagnosis of deeply invasive submucosal cancer (dSM) were compared between BLI magnification and pit pattern analysis. Type C2 in the Hiroshima classification was evaluated separately, because application of this category as an index of the depth of cancer invasion was considered difficult. Results  We analyzed 748 colorectal polyps, excluding 51 polyps that were inflammatory polyps, sessile serrated adenoma/polyps, serrated adenomas, advanced colorectal cancers, or other lesions. The accuracy of differential diagnosis between neoplastic and non-neoplastic lesions was 98.4 % using BLI magnification and 98.7 % with pit pattern analysis. In addition, the diagnostic accuracy of BLI magnification and pit pattern analysis for dSM for cancer was 89.5 % and 92.1 %, respectively. When type C2 lesions were excluded, the diagnostic accuracy of BLI for dSM was 95.9 %. The 18 type C2 lesions comprised 1 adenoma, 9 intramucosal or slightly invasive submucosal cancers, and 8 dSM. Pit pattern analysis allowed accurate diagnosis of the depth of invasion in 13 lesions (72.2 %). Conclusions  Most colorectal polyps could be diagnosed accurately by BLI magnification without pit pattern analysis, but we should add pit pattern analysis for type C2 lesions in the Hiroshima classification.

Integration and binding in rehabilitative sensory substitution: Increasing resolution using a new Zooming-in approach

PubMed Central

Buchs, Galit; Maidenbaum, Shachar; Levy-Tzedek, Shelly; Amedi, Amir

2015-01-01

Purpose: To visually perceive our surroundings we constantly move our eyes and focus on particular details, and then integrate them into a combined whole. Current visual rehabilitation methods, both invasive, like bionic-eyes and non-invasive, like Sensory Substitution Devices (SSDs), down-sample visual stimuli into low-resolution images. Zooming-in to sub-parts of the scene could potentially improve detail perception. Can congenitally blind individuals integrate a ‘visual’ scene when offered this information via different sensory modalities, such as audition? Can they integrate visual information –perceived in parts - into larger percepts despite never having had any visual experience? Methods: We explored these questions using a zooming-in functionality embedded in the EyeMusic visual-to-auditory SSD. Eight blind participants were tasked with identifying cartoon faces by integrating their individual components recognized via the EyeMusic’s zooming mechanism. Results: After specialized training of just 6–10 hours, blind participants successfully and actively integrated facial features into cartooned identities in 79±18% of the trials in a highly significant manner, (chance level 10% ; rank-sum P <  1.55E-04). Conclusions: These findings show that even users who lacked any previous visual experience whatsoever can indeed integrate this visual information with increased resolution. This potentially has important practical visual rehabilitation implications for both invasive and non-invasive methods. PMID:26518671

Zooming in on the cause of the perceptual load effect in the go/no-go paradigm.

PubMed

Chen, Zhe; Cave, Kyle R

2016-08-01

Perceptual load theory (Lavie, 2005) claims that attentional capacity that is not used for the current task is allocated to irrelevant distractors. It predicts that if the attentional demands of the current task are high, distractor interference will be low. One particularly powerful demonstration of perceptual load effects on distractor processing relies on a go/no-go cue that is interpreted by either simple feature detection or feature conjunction (Lavie, 1995). However, a possible alternative interpretation of these effects is that the differential degree of distractor processing is caused by how broadly attention is allocated (attentional zoom) rather than to perceptual load. In 4 experiments, we show that when stimuli are arranged to equalize the extent of spatial attention across conditions, distractor interference varies little whether cues are defined by a simple feature or a conjunction, and that the typical perceptual load effect emerges only when attentional zoom can covary with perceptual load. These results suggest that attentional zoom can account for the differential degree of distractor processing traditionally attributed to perceptual load in the go/no-go paradigm. They also provide new insight into how different factors interact to control distractor interference. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Zooming to the centre of the Milky Way - GigaGalaxy Zoom phase 2

NASA Astrophysics Data System (ADS)

2009-09-01

The second of three images of ESO's GigaGalaxy Zoom project has just been released online. It is a new and wonderful 340-million-pixel vista of the central parts of our home galaxy as seen from ESO's Paranal Observatory with an amateur telescope. This 34 by 20-degree wide image provides us with a view as experienced by amateur astronomers around the world. However, its incredible beauty and appeal owe much to the quality of the observing site and the skills of Stéphane Guisard, the world-renowned astrophotographer, who is also an ESO engineer. This second image directly benefits from the quality of Paranal's sky, one of the best on the planet, where ESO's Very Large Telescope is located. In addition, Guisard has drawn on his professional expertise as an optical engineer specialising in telescopes, a rare combination in the world of astrophotographers. Guisard, as head of the optical engineering team at Paranal, is responsible for ensuring that the Very Large Telescope has the best optical performance possible. To create this stunning, true-colour mosaic of the Galactic Centre region, Guisard assembled about 1200 individual images, totalling more than 200 hours of exposure time, collected over 29 nights, during Guisard's free time, while working during the day at Paranal [1]. The image shows the region spanning the sky from the constellation of Sagittarius (the Archer) to Scorpius (the Scorpion). The very colourful Rho Ophiuchi and Antares region is a prominent feature to the right, although much darker areas, such as the Pipe and Snake nebulae also stand out. The dusty lane of our Milky Way runs obliquely through the image, dotted with remarkable bright, reddish nebulae, such as the Lagoon and the Trifid Nebulae, as well as NGC 6357 and NGC 6334. This dark lane also hosts the very centre of our Galaxy, where a supermassive black hole is lurking. "The area I have depicted in this image is an incredibly rich region of the sky, and the one I find most beautiful

CLASH: Weak-lensing shear-and-magnification analysis of 20 galaxy clusters

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

Umetsu, Keiichi; Czakon, Nicole; Medezinski, Elinor

2014-11-10

We present a joint shear-and-magnification weak-lensing analysis of a sample of 16 X-ray-regular and 4 high-magnification galaxy clusters at 0.19 ≲ z ≲ 0.69 selected from the Cluster Lensing And Supernova survey with Hubble (CLASH). Our analysis uses wide-field multi-color imaging, taken primarily with Suprime-Cam on the Subaru Telescope. From a stacked-shear-only analysis of the X-ray-selected subsample, we detect the ensemble-averaged lensing signal with a total signal-to-noise ratio of ≅ 25 in the radial range of 200-3500 kpc h {sup –1}, providing integrated constraints on the halo profile shape and concentration-mass relation. The stacked tangential-shear signal is well described bymore » a family of standard density profiles predicted for dark-matter-dominated halos in gravitational equilibrium, namely, the Navarro-Frenk-White (NFW), truncated variants of NFW, and Einasto models. For the NFW model, we measure a mean concentration of c{sub 200c}=4.01{sub −0.32}{sup +0.35} at an effective halo mass of M{sub 200c}=1.34{sub −0.09}{sup +0.10}×10{sup 15} M{sub ⊙}. We show that this is in excellent agreement with Λ cold dark matter (ΛCDM) predictions when the CLASH X-ray selection function and projection effects are taken into account. The best-fit Einasto shape parameter is α{sub E}=0.191{sub −0.068}{sup +0.071}, which is consistent with the NFW-equivalent Einasto parameter of ∼0.18. We reconstruct projected mass density profiles of all CLASH clusters from a joint likelihood analysis of shear-and-magnification data and measure cluster masses at several characteristic radii assuming an NFW density profile. We also derive an ensemble-averaged total projected mass profile of the X-ray-selected subsample by stacking their individual mass profiles. The stacked total mass profile, constrained by the shear+magnification data, is shown to be consistent with our shear-based halo-model predictions, including the effects of surrounding large

Hybrid Microscopy: Enabling Inexpensive High-Performance Imaging through Combined Physical and Optical Magnifications

NASA Astrophysics Data System (ADS)

Zhang, Yu Shrike; Chang, Jae-Byum; Alvarez, Mario Moisés; Trujillo-de Santiago, Grissel; Aleman, Julio; Batzaya, Byambaa; Krishnadoss, Vaishali; Ramanujam, Aishwarya Aravamudhan; Kazemzadeh-Narbat, Mehdi; Chen, Fei; Tillberg, Paul W.; Dokmeci, Mehmet Remzi; Boyden, Edward S.; Khademhosseini, Ali

2016-03-01

To date, much effort has been expended on making high-performance microscopes through better instrumentation. Recently, it was discovered that physical magnification of specimens was possible, through a technique called expansion microscopy (ExM), raising the question of whether physical magnification, coupled to inexpensive optics, could together match the performance of high-end optical equipment, at a tiny fraction of the price. Here we show that such “hybrid microscopy” methods—combining physical and optical magnifications—can indeed achieve high performance at low cost. By physically magnifying objects, then imaging them on cheap miniature fluorescence microscopes (“mini-microscopes”), it is possible to image at a resolution comparable to that previously attainable only with benchtop microscopes that present costs orders of magnitude higher. We believe that this unprecedented hybrid technology that combines expansion microscopy, based on physical magnification, and mini-microscopy, relying on conventional optics—a process we refer to as Expansion Mini-Microscopy (ExMM)—is a highly promising alternative method for performing cost-effective, high-resolution imaging of biological samples. With further advancement of the technology, we believe that ExMM will find widespread applications for high-resolution imaging particularly in research and healthcare scenarios in undeveloped countries or remote places.

Analysis of Soot Propensity in Combustion Processes Using Optical Sensors and Video Magnification.

PubMed

Garcés, Hugo O; Fuentes, Andrés; Reszka, Pedro; Carvajal, Gonzalo

2018-05-11

Industrial combustion processes are an important source of particulate matter, causing significant pollution problems that affect human health, and are a major contributor to global warming. The most common method for analyzing the soot emission propensity in flames is the Smoke Point Height (SPH) analysis, which relates the fuel flow rate to a critical flame height at which soot particles begin to leave the reactive zone through the tip of the flame. The SPH and is marked by morphological changes on the flame tip. SPH analysis is normally done through flame observations with the naked eye, leading to high bias. Other techniques are more accurate, but are not practical to implement in industrial settings, such as the Line Of Sight Attenuation (LOSA), which obtains soot volume fractions within the flame from the attenuation of a laser beam. We propose the use of Video Magnification techniques to detect the flame morphological changes and thus determine the SPH minimizing observation bias. We have applied for the first time Eulerian Video Magnification (EVM) and Phase-based Video Magnification (PVM) on an ethylene laminar diffusion flame. The results were compared with LOSA measurements, and indicate that EVM is the most accurate method for SPH determination.

Analysis of Soot Propensity in Combustion Processes Using Optical Sensors and Video Magnification

PubMed Central

Fuentes, Andrés; Reszka, Pedro; Carvajal, Gonzalo

2018-01-01

Industrial combustion processes are an important source of particulate matter, causing significant pollution problems that affect human health, and are a major contributor to global warming. The most common method for analyzing the soot emission propensity in flames is the Smoke Point Height (SPH) analysis, which relates the fuel flow rate to a critical flame height at which soot particles begin to leave the reactive zone through the tip of the flame. The SPH and is marked by morphological changes on the flame tip. SPH analysis is normally done through flame observations with the naked eye, leading to high bias. Other techniques are more accurate, but are not practical to implement in industrial settings, such as the Line Of Sight Attenuation (LOSA), which obtains soot volume fractions within the flame from the attenuation of a laser beam. We propose the use of Video Magnification techniques to detect the flame morphological changes and thus determine the SPH minimizing observation bias. We have applied for the first time Eulerian Video Magnification (EVM) and Phase-based Video Magnification (PVM) on an ethylene laminar diffusion flame. The results were compared with LOSA measurements, and indicate that EVM is the most accurate method for SPH determination. PMID:29751625

Optical design of an athermalised dual field of view step zoom optical system in MWIR

NASA Astrophysics Data System (ADS)

Kucukcelebi, Doruk

2017-08-01

In this paper, the optical design of an athermalised dual field of view step zoom optical system in MWIR (3.7μm - 4.8μm) is described. The dual field of view infrared optical system is designed based on the principle of passive athermalization method not only to achieve athermal optical system but also to keep the high image quality within the working temperature between -40°C and +60°C. The infrared optical system used in this study had a 320 pixel x 256 pixel resolution, 20μm pixel pitch size cooled MWIR focal plane array detector. In this study, the step zoom mechanism, which has the axial motion due to consisting of a lens group, is considered to simplify mechanical structure. The optical design was based on moving a single lens along the optical axis for changing the optical system's field of view not only to reduce the number of moving parts but also to athermalize for the optical system. The optical design began with an optimization process using paraxial optics when first-order optics parameters are determined. During the optimization process, in order to reduce aberrations, such as coma, astigmatism, spherical and chromatic aberrations, aspherical surfaces were used. As a result, athermalised dual field of view step zoom optical design is proposed and the performance of the design using proposed method was verified by providing the focus shifts, spot diagrams and MTF analyzes' plots.

Modified cataract surgery with telescopic magnification for patients with age-related macular degeneration.

PubMed

Iizuka, Megumi; Gorfinkel, John; Mandelcorn, Mark; Lam, Wai-Ching; Devenyi, Robert; Markowitz, Samuel N

2007-12-01

The most desirable effect following cataract surgery in the presence of age-related macular degeneration (AMD) is to obtain an improvement in distance resolution acuity, and the only optical solution to this is the use of telescopic magnification. The purpose of the study was to develop and verify the clinical utility of inducing low-grade telescopic magnification (<33%) at the time of cataract surgery by the choice of an appropriate intraocular lens power and spectacle glasses in patients with AMD and cataract. The design was a prospective, nonrandomized, interventional case series involving 6 patients aged 74-86 (mean 80; SD 4) years with AMD and cataract. Participants were males and females, equal in number, who had visual acuity of less than 20/400 in the weaker eye. Standard cataract surgery was performed in the weaker eye. The power of the intraocular lens was derived from the reduced Gullstrand model of the eye in such a way that at the intraocular lens plane a minus lens was created, which, together with a plus lens in matching glasses, formed a Galilean telescopic system with magnification of up to 33%. Outcome measures were visual acuity, contrast sensitivity, and activities of daily living (ADL) scores. The mean power of the implanted intraocular lenses was 6.31 (SD 2.42) diopters and, according to the theoretical derivations, achieved magnification between 20% and 30% (mean 26%; SD 4.92%). Visual acuity improved for the group from a mean of 20/525 (logMAR 1.48; SD 0.13) to a mean of 20/290 (logMAR 1.20; SD 0.21). Contrast sensitivity improved significantly (p < 0.001) only in the lower spatial frequencies. Postoperatively, ADL scores improved significantly in all patients except one. At the end of the follow-up period, 3 patients reported that they would like to proceed with similar surgery for the other eye. An optimal surgical telescopic device based on low-grade telescopic magnification may improve functional vision for usage in all tasks in AMD

Detection of enhancement in number densities of background galaxies due to magnification by massive galaxy clusters

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

Chiu, I.; Dietrich, J. P.; Mohr, J.

2016-02-18

We present a detection of the enhancement in the number densities of background galaxies induced from lensing magnification and use it to test the Sunyaev-Zel'dovich effect (SZE-) inferred masses in a sample of 19 galaxy clusters with median redshift z similar or equal to 0.42 selected from the South Pole Telescope SPT-SZ survey. These clusters are observed by the Megacam on the Magellan Clay Telescope though gri filters. Two background galaxy populations are selected for this study through their photometric colours; they have median redshifts zmedian similar or equal to 0.9 (low-z background) and z(median) similar or equal to 1.8more » (high-z background). Stacking these populations, we detect the magnification bias effect at 3.3 sigma and 1.3 sigma for the low-and high-z backgrounds, respectively. We fit Navarro, Frenk and White models simultaneously to all observed magnification bias profiles to estimate the multiplicative factor. that describes the ratio of the weak lensing mass to the mass inferred from the SZE observable-mass relation. We further quantify systematic uncertainties in. resulting from the photometric noise and bias, the cluster galaxy contamination and the estimations of the background properties. The resulting. for the combined background populations with 1 sigma uncertainties is 0.83 +/- 0.24(stat) +/- 0.074(sys), indicating good consistency between the lensing and the SZE-inferred masses. We use our best-fitting eta to predict the weak lensing shear profiles and compare these predictions with observations, showing agreement between the magnification and shear mass constraints. This work demonstrates the promise of using the magnification as a complementary method to estimate cluster masses in large surveys.« less

Adaptive zooming in X-ray computed tomography.

PubMed

Dabravolski, Andrei; Batenburg, Kees Joost; Sijbers, Jan

2014-01-01

In computed tomography (CT), the source-detector system commonly rotates around the object in a circular trajectory. Such a trajectory does not allow to exploit a detector fully when scanning elongated objects. Increase the spatial resolution of the reconstructed image by optimal zooming during scanning. A new approach is proposed, in which the full width of the detector is exploited for every projection angle. This approach is based on the use of prior information about the object's convex hull to move the source as close as possible to the object, while avoiding truncation of the projections. Experiments show that the proposed approach can significantly improve reconstruction quality, producing reconstructions with smaller errors and revealing more details in the object. The proposed approach can lead to more accurate reconstructions and increased spatial resolution in the object compared to the conventional circular trajectory.

Dual-focus Magnification, High-Definition Endoscopy Improves Pathology Detection in Direct-to-Test Diagnostic Upper Gastrointestinal Endoscopy.

PubMed

Bond, Ashley; Burkitt, Michael D; Cox, Trevor; Smart, Howard L; Probert, Chris; Haslam, Neil; Sarkar, Sanchoy

2017-03-01

In the UK, the majority of diagnostic upper gastrointestinal (UGI) endoscopies are a result of direct-to-test referral from the primary care physician. The diagnostic yield of these tests is relatively low, and the burden high on endoscopy services. Dual-focus magnification, high-definition endoscopy is expected to improve detection and classification of UGI mucosal lesions and also help minimize biopsies by allowing better targeting. This is a retrospective study of patients attending for direct-to-test UGI endoscopy from January 2015 to June 2015. The primary outcome of interest was the identification of significant pathology. Detection of significant pathology was modelled using logistic regression. 500 procedures were included. The mean age of patients was 61.5 (±15.6) years; 60.8% of patients were female. Ninety-four gastroscopies were performed using dual-focus magnification high-definition endoscopy. Increasing age, male gender, type of endoscope, and type of operator were all identified as significant factors influencing the odds of detecting significant mucosal pathology. Use of dual-focus magnification, high-definition endoscopy was associated with an odds ratio of 1.87 (95%CI 1.11-3.12) favouring the detection of significant pathology. Subsequent analysis suggested that the increased detection of pathology during dual-focus magnification, high-definition endoscopy also influenced patient follow-up and led to a 3.0 fold (p=0.04) increase in the proportion of patients entered into an UGI endoscopic surveillance program. Dual-focus magnification, high-definition endoscopy improved the diagnostic yield for significant mucosal pathology in patients referred for direct-to-test endoscopy. If this finding is recapitulated elsewhere it will have substantial impact on the provision of UGI endoscopic services.

Object Based Numerical Zooming Between the NPSS Version 1 and a 1-Dimensional Meanline High Pressure Compressor Design Analysis Code

NASA Technical Reports Server (NTRS)

Follen, G.; Naiman, C.; auBuchon, M.

2000-01-01

Within NASA's High Performance Computing and Communication (HPCC) program, NASA Glenn Research Center is developing an environment for the analysis/design of propulsion systems for aircraft and space vehicles called the Numerical Propulsion System Simulation (NPSS). The NPSS focuses on the integration of multiple disciplines such as aerodynamics, structures, and heat transfer, along with the concept of numerical zooming between 0- Dimensional to 1-, 2-, and 3-dimensional component engine codes. The vision for NPSS is to create a "numerical test cell" enabling full engine simulations overnight on cost-effective computing platforms. Current "state-of-the-art" engine simulations are 0-dimensional in that there is there is no axial, radial or circumferential resolution within a given component (e.g. a compressor or turbine has no internal station designations). In these 0-dimensional cycle simulations the individual component performance characteristics typically come from a table look-up (map) with adjustments for off-design effects such as variable geometry, Reynolds effects, and clearances. Zooming one or more of the engine components to a higher order, physics-based analysis means a higher order code is executed and the results from this analysis are used to adjust the 0-dimensional component performance characteristics within the system simulation. By drawing on the results from more predictive, physics based higher order analysis codes, "cycle" simulations are refined to closely model and predict the complex physical processes inherent to engines. As part of the overall development of the NPSS, NASA and industry began the process of defining and implementing an object class structure that enables Numerical Zooming between the NPSS Version I (0-dimension) and higher order 1-, 2- and 3-dimensional analysis codes. The NPSS Version I preserves the historical cycle engineering practices but also extends these classical practices into the area of numerical zooming for

The Trilogy is Complete - GigaGalaxy Zoom Phase 3

NASA Astrophysics Data System (ADS)

2009-09-01

The third image of ESO's GigaGalaxy Zoom project has just been released online, completing this eye-opening dive into our galactic home in outstanding fashion. The latest image follows on from views, released over the last two weeks, of the sky as seen with the unaided eye and through an amateur telescope. This third instalment provides another breathtaking vista of an astronomical object, this time a 370-million-pixel view of the Lagoon Nebula of the quality and depth needed by professional astronomers in their quest to understand our Universe. The newly released image extends across a field of view of more than one and a half square degree - an area eight times larger than that of the full Moon - and was obtained with the Wide Field Imager attached to the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. This 67-million-pixel camera has already created several of ESO's iconic pictures. The intriguing object depicted here - the Lagoon Nebula - is located four to five thousand light-years away towards the constellation of Sagittarius (the Archer). The nebula is a giant interstellar cloud, 100 light-years across, where stars are forming. The scattered dark patches seen all over the nebula are huge clouds of gas and dust that are collapsing under their own weight and which will soon give birth to clusters of young, glowing stars. Some of the smallest clouds are known as "globules" and the most prominent ones have been catalogued by the astronomer Edward Emerson Barnard. The Lagoon Nebula hosts the young open stellar cluster known as NGC 6530. This is home for 50 to 100 stars and twinkles in the lower left portion of the nebula. Observations suggest that the cluster is slightly in front of the nebula itself, though still enshrouded by dust, as revealed by reddening of the starlight, an effect that occurs when small dust particles scatter light. The name of the Lagoon Nebula derives from the wide lagoon-shaped dark lane located in the middle of the

Motion magnification for endoscopic surgery

NASA Astrophysics Data System (ADS)

McLeod, A. Jonathan; Baxter, John S. H.; de Ribaupierre, Sandrine; Peters, Terry M.

2014-03-01

Endoscopic and laparoscopic surgeries are used for many minimally invasive procedures but limit the visual and haptic feedback available to the surgeon. This can make vessel sparing procedures particularly challenging to perform. Previous approaches have focused on hardware intensive intraoperative imaging or augmented reality systems that are difficult to integrate into the operating room. This paper presents a simple approach in which motion is visually enhanced in the endoscopic video to reveal pulsating arteries. This is accomplished by amplifying subtle, periodic changes in intensity coinciding with the patient's pulse. This method is then applied to two procedures to illustrate its potential. The first, endoscopic third ventriculostomy, is a neurosurgical procedure where the floor of the third ventricle must be fenestrated without injury to the basilar artery. The second, nerve-sparing robotic prostatectomy, involves removing the prostate while limiting damage to the neurovascular bundles. In both procedures, motion magnification can enhance subtle pulsation in these structures to aid in identifying and avoiding them.

External versus internal triggers of bar formation in cosmological zoom-in simulations

NASA Astrophysics Data System (ADS)

Zana, Tommaso; Dotti, Massimo; Capelo, Pedro R.; Bonoli, Silvia; Haardt, Francesco; Mayer, Lucio; Spinoso, Daniele

2018-01-01

The emergence of a large-scale stellar bar is one of the most striking features in disc galaxies. By means of state-of-the-art cosmological zoom-in simulations, we study the formation and evolution of bars in Milky Way-like galaxies in a fully cosmological context, including the physics of gas dissipation, star formation and supernova feedback. Our goal is to characterize the actual trigger of the non-axisymmetric perturbation that leads to the strong bar observable in the simulations at z = 0, discriminating between an internal/secular and an external/tidal origin. To this aim, we run a suite of cosmological zoom-in simulations altering the original history of galaxy-satellite interactions at a time when the main galaxy, though already bar-unstable, does not feature any non-axisymmetric structure yet. We find that the main effect of a late minor merger and of a close fly-by is to delay the time of bar formation and those two dynamical events are not directly responsible for the development of the bar and do not alter significantly its global properties (e.g. its final extension). We conclude that, once the disc has grown to a mass large enough to sustain global non-axisymmetric modes, then bar formation is inevitable.

Comparison of techniques for correction of magnification of pelvic X-rays for hip surgery planning.

PubMed

The, Bertram; Kootstra, Johan W J; Hosman, Anton H; Verdonschot, Nico; Gerritsma, Carina L E; Diercks, Ron L

2007-12-01

The aim of this study was to develop an accurate method for correction of magnification of pelvic x-rays to enhance accuracy of hip surgery planning. All investigated methods aim at estimating the anteroposterior location of the hip joint in supine position to correctly position a reference object for correction of magnification. An existing method-which is currently being used in clinical practice in our clinics-is based on estimating the position of the hip joint by palpation of the greater trochanter. It is only moderately accurate and difficult to execute reliably in clinical practice. To develop a new method, 99 patients who already had a hip implant in situ were included; this enabled determining the true location of the hip joint deducted from the magnification of the prosthesis. Physical examination was used to obtain predictor variables possibly associated with the height of the hip joint. This included a simple dynamic hip joint examination to estimate the position of the center of rotation. Prediction equations were then constructed using regression analysis. The performance of these prediction equations was compared with the performance of the existing protocol. The mean absolute error in predicting the height of the hip joint center using the old method was 20 mm (range -79 mm to +46 mm). This was 11 mm for the new method (-32 mm to +39 mm). The prediction equation is: height (mm) = 34 + 1/2 abdominal circumference (cm). The newly developed prediction equation is a superior method for predicting the height of the hip joint center for correction of magnification of pelvic x-rays. We recommend its implementation in the departments of radiology and orthopedic surgery.

Noisy image magnification with total variation regularization and order-changed dictionary learning

NASA Astrophysics Data System (ADS)

Xu, Jian; Chang, Zhiguo; Fan, Jiulun; Zhao, Xiaoqiang; Wu, Xiaomin; Wang, Yanzi

2015-12-01

Noisy low resolution (LR) images are always obtained in real applications, but many existing image magnification algorithms can not get good result from a noisy LR image. We propose a two-step image magnification algorithm to solve this problem. The proposed algorithm takes the advantages of both regularization-based method and learning-based method. The first step is based on total variation (TV) regularization and the second step is based on sparse representation. In the first step, we add a constraint on the TV regularization model to magnify the LR image and at the same time to suppress the noise in it. In the second step, we propose an order-changed dictionary training algorithm to train the dictionaries which is dominated by texture details. Experimental results demonstrate that the proposed algorithm performs better than many other algorithms when the noise is not serious. The proposed algorithm can also provide better visual quality on natural LR images.

Three-dimensional motion-picture imaging of dynamic object by parallel-phase-shifting digital holographic microscopy using an inverted magnification optical system

NASA Astrophysics Data System (ADS)

Fukuda, Takahito; Shinomura, Masato; Xia, Peng; Awatsuji, Yasuhiro; Nishio, Kenzo; Matoba, Osamu

2017-04-01

We constructed a parallel-phase-shifting digital holographic microscopy (PPSDHM) system using an inverted magnification optical system, and succeeded in three-dimensional (3D) motion-picture imaging for 3D displacement of a microscopic object. In the PPSDHM system, the inverted and afocal magnification optical system consisted of a microscope objective (16.56 mm focal length and 0.25 numerical aperture) and a convex lens (300 mm focal length and 82 mm aperture diameter). A polarization-imaging camera was used to record multiple phase-shifted holograms with a single-shot exposure. We recorded an alum crystal, sinking down in aqueous solution of alum, by the constructed PPSDHM system at 60 frames/s for about 20 s and reconstructed high-quality 3D motion-picture image of the crystal. Then, we calculated amounts of displacement of the crystal from the amounts in the focus plane and the magnifications of the magnification optical system, and obtained the 3D trajectory of the crystal by that amounts.

Duodenal villous morphology assessed using magnification narrow band imaging correlates well with histology in patients with suspected malabsorption syndrome.

PubMed

Dutta, Amit Kumar; Sajith, Kattiparambil Gangadharan; Shah, Gautam; Pulimood, Anna Benjamin; Simon, Ebby George; Joseph, Anjilivelil Joseph; Chacko, Ashok

2014-11-01

Narrow band imaging with magnification enables detailed assessment of duodenal villi and may be useful in predicting the presence of villous atrophy or normal villi. We aimed to assess the morphology of duodenal villi using magnification narrow band imaging and correlate it with histology findings in patients with clinically suspected malabsorption syndrome. Patients with clinical suspicion of malabsorption presenting at a tertiary care center were prospectively recruited in this diagnostic intervention study. Patients underwent upper gastrointestinal endoscopy using magnification narrow band imaging. The villous morphology in the second part of the duodenum was assessed independently by two endoscopists and the presence of normal or atrophic villi was recorded. Biopsy specimen was obtained from the same area and was examined by two pathologists together. The sensitivity and specificity of magnification narrow band imaging in detecting the presence of duodenal villous atrophy was calculated and compared to the histology. One hundred patients with clinically suspected malabsorption were included in this study. Sixteen patients had histologically confirmed villous atrophy. The sensitivity and specificity of narrow band imaging in predicting villous atrophy was 87.5% and 95.2%, respectively, for one endoscopist. The corresponding figures for the second endoscopist were 81.3% and 92.9%, respectively. The interobserver agreement was very good with a kappa value of 0.87. Magnification narrow band imaging performed very well in predicting duodenal villous morphology. This may help in carrying out targeted biopsies and avoiding unnecessary biopsies in patients with suspected malabsorption. © 2014 The Authors. Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society.

Probing dark energy with lensing magnification in photometric surveys.

PubMed

Schneider, Michael D

2014-02-14

I present an estimator for the angular cross correlation of two tracers of the cosmological large-scale structure that utilizes redshift information to isolate separate physical contributions. The estimator is derived by solving the Limber equation for a reweighting of the foreground tracer that nulls either clustering or lensing contributions to the cross correlation function. Applied to future photometric surveys, the estimator can enhance the measurement of gravitational lensing magnification effects to provide a competitive independent constraint on the dark energy equation of state.

Leaf vein length per unit area is not intrinsically dependent on image magnification: avoiding measurement artifacts for accuracy and precision.

PubMed

Sack, Lawren; Caringella, Marissa; Scoffoni, Christine; Mason, Chase; Rawls, Michael; Markesteijn, Lars; Poorter, Lourens

2014-10-01

Leaf vein length per unit leaf area (VLA; also known as vein density) is an important determinant of water and sugar transport, photosynthetic function, and biomechanical support. A range of software methods are in use to visualize and measure vein systems in cleared leaf images; typically, users locate veins by digital tracing, but recent articles introduced software by which users can locate veins using thresholding (i.e. based on the contrasting of veins in the image). Based on the use of this method, a recent study argued against the existence of a fixed VLA value for a given leaf, proposing instead that VLA increases with the magnification of the image due to intrinsic properties of the vein system, and recommended that future measurements use a common, low image magnification for measurements. We tested these claims with new measurements using the software LEAFGUI in comparison with digital tracing using ImageJ software. We found that the apparent increase of VLA with magnification was an artifact of (1) using low-quality and low-magnification images and (2) errors in the algorithms of LEAFGUI. Given the use of images of sufficient magnification and quality, and analysis with error-free software, the VLA can be measured precisely and accurately. These findings point to important principles for improving the quantity and quality of important information gathered from leaf vein systems. © 2014 American Society of Plant Biologists. All Rights Reserved.

Use of loupes magnification and microsurgical technique in thyroid surgery: ten years experience in a single center

PubMed Central

D’ORAZI, V.; PANUNZI, A.; DI LORENZO, E.; ORTENSI, AL.; CIALINI, M.; ANICHINI, S.; ORTENSI, A.

2016-01-01

Aim The use of microsurgical technique and loupes magnification as a support to traditional surgery can help surgical performance and prevent complications in thyroid surgery. Patients and methods Between January 2004 and December 2014, 782 patients with thyroid diseases were operated by our team with microsurgical technique and loupes magnification 4.5x. All patients had pre and postoperative vocal cords assessment and calcemia and the collected data were analysed. Results Among the 782 patients, only six patients (0.77%) had unilateral vocal fold immobility treated with medical therapy, phoniatric and neck physiotherapy. All six patients showed complete laryngeal recovery of motility 6/8 weeks after treatment. There were not cases of permanent monolateral or bilateral vocal cord palsy. In 84 patients there were signs and symptoms of hypocalcemia. In 81 patients (10.36%) the restoring of biochemical parameters and the resolution of symptoms occurred between 2 and 6 weeks and in 3 cases (0.38%) there was permanent hypocalcemia more than six months. Conclusion The use of microsurgical technique and loupes magnification in thyroid surgery are safety and effective procedures, that require an appropriate training in reconstructive microsurgery, but may significantly reduce post-operative complications. Here, we report for the first time the largest series of thyroid surgery performed with the use of microsurgical technique and loupes magnification, analysing the postoperative morbidity. In view of our results, we suggest the routine use of 4.5X loupes and microsurgical technique in thyroid surgery. PMID:27734792

THE SYSTEMATICS OF STRONG LENS MODELING QUANTIFIED: THE EFFECTS OF CONSTRAINT SELECTION AND REDSHIFT INFORMATION ON MAGNIFICATION, MASS, AND MULTIPLE IMAGE PREDICTABILITY

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

Johnson, Traci L.; Sharon, Keren, E-mail: tljohn@umich.edu

Until now, systematic errors in strong gravitational lens modeling have been acknowledged but have never been fully quantified. Here, we launch an investigation into the systematics induced by constraint selection. We model the simulated cluster Ares 362 times using random selections of image systems with and without spectroscopic redshifts and quantify the systematics using several diagnostics: image predictability, accuracy of model-predicted redshifts, enclosed mass, and magnification. We find that for models with >15 image systems, the image plane rms does not decrease significantly when more systems are added; however, the rms values quoted in the literature may be misleading asmore » to the ability of a model to predict new multiple images. The mass is well constrained near the Einstein radius in all cases, and systematic error drops to <2% for models using >10 image systems. Magnification errors are smallest along the straight portions of the critical curve, and the value of the magnification is systematically lower near curved portions. For >15 systems, the systematic error on magnification is ∼2%. We report no trend in magnification error with the fraction of spectroscopic image systems when selecting constraints at random; however, when using the same selection of constraints, increasing this fraction up to ∼0.5 will increase model accuracy. The results suggest that the selection of constraints, rather than quantity alone, determines the accuracy of the magnification. We note that spectroscopic follow-up of at least a few image systems is crucial because models without any spectroscopic redshifts are inaccurate across all of our diagnostics.« less

The Systematics of Strong Lens Modeling Quantified: The Effects of Constraint Selection and Redshift Information on Magnification, Mass, and Multiple Image Predictability

NASA Astrophysics Data System (ADS)

Johnson, Traci L.; Sharon, Keren

2016-11-01

Until now, systematic errors in strong gravitational lens modeling have been acknowledged but have never been fully quantified. Here, we launch an investigation into the systematics induced by constraint selection. We model the simulated cluster Ares 362 times using random selections of image systems with and without spectroscopic redshifts and quantify the systematics using several diagnostics: image predictability, accuracy of model-predicted redshifts, enclosed mass, and magnification. We find that for models with >15 image systems, the image plane rms does not decrease significantly when more systems are added; however, the rms values quoted in the literature may be misleading as to the ability of a model to predict new multiple images. The mass is well constrained near the Einstein radius in all cases, and systematic error drops to <2% for models using >10 image systems. Magnification errors are smallest along the straight portions of the critical curve, and the value of the magnification is systematically lower near curved portions. For >15 systems, the systematic error on magnification is ∼2%. We report no trend in magnification error with the fraction of spectroscopic image systems when selecting constraints at random; however, when using the same selection of constraints, increasing this fraction up to ∼0.5 will increase model accuracy. The results suggest that the selection of constraints, rather than quantity alone, determines the accuracy of the magnification. We note that spectroscopic follow-up of at least a few image systems is crucial because models without any spectroscopic redshifts are inaccurate across all of our diagnostics.

Fatigue Magnification Factors of Arc-Soft-Toe Bracket Joints

NASA Astrophysics Data System (ADS)

Fu, Qiang; Li, Huajun; Wang, Hongqing; Wang, Shuqing; Li, Dejiang; Li, Qun; Fang, Hui

2018-06-01

Arc-soft-toe bracket (ASTB), as a joint structure in the marine structure, is the hot spot with significant stress concentration, therefore, fatigue behavior of ASTBs is an important point of concern in their design. Since macroscopic geometric factors obviously influence the stress flaws in joints, the shapes and sizes of ASTBs should represent the stress distribution around cracks in the hot spots. In this paper, we introduce a geometric magnification factor for reflecting the macroscopic geometric effects of ASTB crack features and construct a 3D finite element model to simulate the distribution of stress intensity factor (SIF) at the crack endings. Sensitivity analyses with respect to the geometric ratio H t / L b , R/ L b , L t / L b are performed, and the relations between the geometric factor and these parameters are presented. A set of parametric equations with respect to the geometric magnification factor is obtained using a curve fitting technique. A nonlinear relationship exists between the SIF and the ratio of ASTB arm to toe length. When the ratio of ASTB arm to toe length reaches a marginal value, the SIF of crack at the ASTB toe is not influenced by ASTB geometric parameters. In addition, the arc shape of the ASTB slope edge can transform the stress flowing path, which significantly affects the SIF at the ASTB toe. A proper method to reduce stress concentration is setting a slope edge arc size equal to the ASTB arm length.

Awareness, Attitude, and Prevalence of usage of magnification devices among the dental practitioners in the state of Andhra Pradesh – A questionnaire-based study

PubMed Central

Penmetsa, Gautami Subhadra; Mani, Loda Princee; Praveen, Gadde; Dwarakanath, Chini Dorai; Suresh, S.

2017-01-01

Background: Dentistry, dealing with teeth and supporting tissues in the oral cavity is not only an ever-evolving science but also an art combined with good eye-hand coordination. It not only encompasses clinical and theoretical skills which play a crucial role in the success of therapy but also a lot of intrinsic work is accomplished in dentistry. In a journey to fulfill the above accomplishments and for facilitating early diagnosis of pathologies which usually go unnoticed, a clearer and magnified field of vision are also essential. The purpose of this study is to evaluate the awareness, attitude, and prevalence of the usage of magnification devices among the dental practitioners in the state of Andhra Pradesh. Materials and Methods: A questionnaire-based study was conducted to assess the awareness, attitude, and prevalence of magnification devices among the 370 dental practitioners in Andhra Pradesh. All the participants were provided with a prestructured questionnaire comprising of 24 questions and answering was completely self-based. Results: Among the participants, majority were aware about magnification in dentistry (91.1%), and also of the different types of magnification devices available (90.5%). On the other hand, when the reason for not using magnification devices was taken into consideration, 32.7% attributed that they have not experienced the devices and 32.4% felt that devices were too expensive. Moreover, when regarding the usage of devices was taken into account, only 23.8% of the total participants were exposed to the usage of magnification aids. Conclusion: Among the selected group of participants, even though majority were aware of magnification in dentistry its application in practice was very less. PMID:29491587

Measurement system of the refractive power of spherical and sphero-cylindrical lenses with the magnification ellipse fitting method.

PubMed

Ko, Wooseok; Kim, Soohyun

2009-11-01

This paper proposes a new measurement system for measuring the refractive power of spherical and sphero-cylindrical lenses with a six-point light source, which is composed of a light emitting diode and a six-hole pattern aperture, and magnification ellipse fitting method. The position of the six light sources is changed into a circular or elliptical form subjected to the lens refractive power and meridian rotation angle. The magnification ellipse fitting method calculates the lens refractive power based on the ellipse equation with magnifications that are the ratios between initial diagonal lengths and measured diagonal lengths of the conjugated light sources changed by the target lens. The refractive powers of the spherical and sphero-cylindrical lenses certified in the Korea Research Institute of Standard and Science were measured to verify the measurement performance. The proposed method is estimated to have a repeatability of +/-0.01 D and an error value below 1%.

THE MASS-RICHNESS RELATION OF MaxBCG CLUSTERS FROM QUASAR LENSING MAGNIFICATION USING VARIABILITY

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

Bauer, Anne H.; Baltay, Charles; Ellman, Nancy

2012-04-10

Accurate measurement of galaxy cluster masses is an essential component not only in studies of cluster physics but also for probes of cosmology. However, different mass measurement techniques frequently yield discrepant results. The Sloan Digital Sky Survey MaxBCG catalog's mass-richness relation has previously been constrained using weak lensing shear, Sunyaev-Zeldovich (SZ), and X-ray measurements. The mass normalization of the clusters as measured by weak lensing shear is {approx}>25% higher than that measured using SZ and X-ray methods, a difference much larger than the stated measurement errors in the analyses. We constrain the mass-richness relation of the MaxBCG galaxy cluster catalogmore » by measuring the gravitational lensing magnification of type I quasars in the background of the clusters. The magnification is determined using the quasars' variability and the correlation between quasars' variability amplitude and intrinsic luminosity. The mass-richness relation determined through magnification is in agreement with that measured using shear, confirming that the lensing strength of the clusters implies a high mass normalization and that the discrepancy with other methods is not due to a shear-related systematic measurement error. We study the dependence of the measured mass normalization on the cluster halo orientation. As expected, line-of-sight clusters yield a higher normalization; however, this minority of haloes does not significantly bias the average mass-richness relation of the catalog.« less

Trend of digital camera and interchangeable zoom lenses with high ratio based on patent application over the past 10 years

NASA Astrophysics Data System (ADS)

Sensui, Takayuki

2012-10-01

Although digitalization has tripled consumer-class camera market scale, extreme reductions in prices of fixed-lens cameras has reduced profitability. As a result, a number of manufacturers have entered the market of the System DSC i.e. digital still camera with interchangeable lens, where large profit margins are possible, and many high ratio zoom lenses with image stabilization functions have been released. Quiet actuators are another indispensable component. Design with which there is little degradation in performance due to all types of errors is preferred for good balance in terms of size, lens performance, and the rate of quality to sub-standard products. Decentering, such as that caused by tilting, sensitivity of moving groups is especially important. In addition, image stabilization mechanisms actively shift lens groups. Development of high ratio zoom lenses with vibration reduction mechanism is confronted by the challenge of reduced performance due to decentering, making control over decentering sensitivity between lens groups everything. While there are a number of ways to align lenses (axial alignment), shock resistance and ability to stand up to environmental conditions must also be considered. Naturally, it is very difficult, if not impossible, to make lenses smaller and achieve a low decentering sensitivity at the same time. 4-group zoom construction is beneficial in making lenses smaller, but decentering sensitivity is greater. 5-group zoom configuration makes smaller lenses more difficult, but it enables lower decentering sensitivities. At Nikon, the most advantageous construction is selected for each lens based on specifications. The AF-S DX NIKKOR 18-200mm f/3.5-5.6G ED VR II and AF-S NIKKOR 28-300mm f/3.5-5.6G ED VR are excellent examples of this.

Varo-achro-phobia: the fear of broad spectrum zoom optics

NASA Astrophysics Data System (ADS)

Vogel, Steven; Pollica, Naomi

2015-05-01

Today's battlefield is evolving at light speed. Our war fighters are being tasked with highly complex missions requiring the very best technology our industry can offer. The demand for advanced ISR platforms is challenging designers and engineers in the optics industry to push the envelope and develop wider band solutions to support multiple and broadband sensor platforms. Recently, significant attention has been directed towards the development of optical systems that enable simultaneous operation in the visible and shortwave infrared spectral wavebands. This paper will present a review of the evolution of StingRay Optics' GhostSight™ continuous zoom optics that offer broad chromatic imaging capabilities from the visible through the shortwave infrared spectrum.

Precision technique for trimming dies using a magnification device.

PubMed

Beck, D B

1980-05-01

This article described a technique for trimming a die under magnification. However, the microscope is also useful for checking (1) margins of wax patterns for completeness, (2) the internal surfaces of castings for imperfections, bubbles, or retained investment particles which could prevent proper seating of the castings on the dies, (3) for cracks or contamination in dental porcelain as well as porcelain flash on margins; and (4) precision attachment operation after casting or soldering procedures. Attention to detail in these laboratory procedures greatly improves the final fit of dental castings and saves subsequent chairside adjustments and remakes.

Launch Condition Deviations of Reusable Launch Vehicle Simulations in Exo-Atmospheric Zoom Climbs

NASA Technical Reports Server (NTRS)

Urschel, Peter H.; Cox, Timothy H.

2003-01-01

The Defense Advanced Research Projects Agency has proposed a two-stage system to deliver a small payload to orbit. The proposal calls for an airplane to perform an exo-atmospheric zoom climb maneuver, from which a second-stage rocket is launched carrying the payload into orbit. The NASA Dryden Flight Research Center has conducted an in-house generic simulation study to determine how accurately a human-piloted airplane can deliver a second-stage rocket to a desired exo-atmospheric launch condition. A high-performance, fighter-type, fixed-base, real-time, pilot-in-the-loop airplane simulation has been modified to perform exo-atmospheric zoom climb maneuvers. Four research pilots tracked a reference trajectory in the presence of winds, initial offsets, and degraded engine thrust to a second-stage launch condition. These launch conditions have been compared to the reference launch condition to characterize the expected deviation. At each launch condition, a speed change was applied to the second-stage rocket to insert the payload onto a transfer orbit to the desired operational orbit. The most sensitive of the test cases was the degraded thrust case, yielding second-stage launch energies that were too low to achieve the radius of the desired operational orbit. The handling qualities of the airplane, as a first-stage vehicle, have also been investigated.

Variable magnification variable dispersion glancing incidence imaging x-ray spectroscopic telescope

NASA Technical Reports Server (NTRS)

Hoover, Richard B. (Inventor)

1991-01-01

A variable magnification variable dispersion glancing incidence x-ray spectroscopic telescope capable of multiple high spatial revolution imaging at precise spectral lines of solar and stellar x-ray and extreme ultraviolet radiation sources includes a pirmary optical system which focuses the incoming radiation to a primary focus. Two or more rotatable carries each providing a different magnification are positioned behind the primary focus at an inclination to the optical axis, each carrier carrying a series of ellipsoidal diffraction grating mirrors each having a concave surface on which the gratings are ruled and coated with a mutlilayer coating to reflect by diffraction a different desired wavelength. The diffraction grating mirrors of both carriers are segments of ellipsoids having a common first focus coincident with the primary focus. A contoured detector such as an x-ray sensitive photogrpahic film is positioned at the second respective focus of each diffraction grating so that each grating may reflect the image at the first focus to the detector at the second focus. The carriers are selectively rotated to position a selected mirror for receiving radiation from the primary optical system, and at least the first carrier may be withdrawn from the path of the radiation to permit a selected grating on the second carrier to receive radiation.

Variable magnification variable dispersion glancing incidence imaging x ray spectroscopic telescope

NASA Technical Reports Server (NTRS)

Hoover, Richard (Inventor)

1990-01-01

A variable magnification variable dispersion glancing incidence x ray spectroscopic telescope capable of multiple high spatial revolution imaging at precise spectral lines of solar and stellar x ray and extreme ultraviolet radiation sources includes a primary optical system which focuses the incoming radiation to a primary focus. Two or more rotatable carriers each providing a different magnification are positioned behind the primary focus at an inclination to the optical axis, each carrier carrying a series of ellipsoidal diffraction grating mirrors each having a concave surface on which the gratings are ruled and coated with a multilayer coating to reflect by diffraction a different desired wavelength. The diffraction grating mirrors of both carriers are segments of ellipsoids having a common first focus coincident with the primary focus. A contoured detector such as an x ray sensitive photographic film is positioned at the second respective focus of each diffraction grating so that each grating may reflect the image at the first focus to the detector at the second focus. The carriers are selectively rotated to position a selected mirror for receiving radiation from the primary optical system, and at least the first carrier may be withdrawn from the path of the radiation to permit a selected grating on the second carrier to receive radiation.

Can we see photosynthesis? Magnifying the tiny color changes of plant green leaves using Eulerian video magnification

NASA Astrophysics Data System (ADS)

Taj-Eddin, Islam A. T. F.; Afifi, Mahmoud; Korashy, Mostafa; Ahmed, Ali H.; Cheng, Ng Yoke; Hernandez, Evelyng; Abdel-Latif, Salma M.

2017-11-01

Plant aliveness is proven through laboratory experiments and special scientific instruments. We aim to detect the degree of animation of plants based on the magnification of the small color changes in the plant's green leaves using the Eulerian video magnification. Capturing the video under a controlled environment, e.g., using a tripod and direct current light sources, reduces camera movements and minimizes light fluctuations; we aim to reduce the external factors as much as possible. The acquired video is then stabilized and a proposed algorithm is used to reduce the illumination variations. Finally, the Euler magnification is utilized to magnify the color changes on the light invariant video. The proposed system does not require any special purpose instruments as it uses a digital camera with a regular frame rate. The results of magnified color changes on both natural and plastic leaves show that the live green leaves have color changes in contrast to the plastic leaves. Hence, we can argue that the color changes of the leaves are due to biological operations, such as photosynthesis. To date, this is possibly the first work that focuses on interpreting visually, some biological operations of plants without any special purpose instruments.

Smartphone Magnification Attachment: Microscope or Magnifying Glass

NASA Astrophysics Data System (ADS)

Hergemöller, Timo; Laumann, Daniel

2017-09-01

Today smartphones and tablets do not merely pervade our daily life, but also play a major role in STEM education in general, and in experimental investigations in particular. Enabling teachers and students to make use of these new techniques in physics lessons requires supplying capable and affordable applications. Our article presents the improvement of a low-cost technique turning smartphones into powerful magnifying glasses or microscopes. Adding only a 3D-printed clip attached to the smartphone's camera and inserting a small glass bead in this clip enables smartphones to take pictures with up to 780x magnification (see Fig. 1). In addition, the construction of the smartphone attachments helps to explain and examine the differences between magnifying glasses and microscopes, and shows that the widespread term "smartphone microscope" for this technique is inaccurate from a physics educational perspective.

Tunable Metasurface and Flat Optical Zoom Lens on a Stretchable Substrate.

PubMed

Ee, Ho-Seok; Agarwal, Ritesh

2016-04-13

A mechanically reconfigurable metasurface that can continuously tune the wavefront is demonstrated in the visible frequency range by changing the lattice constant of a complex Au nanorod array fabricated on a stretchable polydimethylsiloxane substrate. It is shown that the anomalous refraction angle of visible light at 632.8 nm interacting with the tunable metasurface can be adjusted from 11.4° to 14.9° by stretching the substrate by ∼30%. An ultrathin flat 1.7× zoom lens whose focal length can continuously be changed from 150 to 250 μm is realized, which also demonstrates the potential of utilizing metasurfaces for reconfigurable flat optics.

Time delay and magnification centroid due to gravitational lensing by black holes and naked singularities

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

Virbhadra, K. S.; Keeton, C. R.; Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854

We model the massive dark object at the center of the Galaxy as a Schwarzschild black hole as well as Janis-Newman-Winicour naked singularities, characterized by the mass and scalar charge parameters, and study gravitational lensing (particularly time delay, magnification centroid, and total magnification) by them. We find that the lensing features are qualitatively similar (though quantitatively different) for Schwarzschild black holes, weakly naked, and marginally strongly naked singularities. However, the lensing characteristics of strongly naked singularities are qualitatively very different from those due to Schwarzschild black holes. The images produced by Schwarzschild black hole lenses and weakly naked and marginallymore » strongly naked singularity lenses always have positive time delays. On the other hand, strongly naked singularity lenses can give rise to images with positive, zero, or negative time delays. In particular, for a large angular source position the direct image (the outermost image on the same side as the source) due to strongly naked singularity lensing always has a negative time delay. We also found that the scalar field decreases the time delay and increases the total magnification of images; this result could have important implications for cosmology. As the Janis-Newman-Winicour metric also describes the exterior gravitational field of a scalar star, naked singularities as well as scalar star lenses, if these exist in nature, will serve as more efficient cosmic telescopes than regular gravitational lenses.« less

Beyond concordance cosmology with magnification of gravitational-wave standard sirens.

PubMed

Camera, Stefano; Nishizawa, Atsushi

2013-04-12

We show how future gravitational-wave detectors would be able to discriminate between the concordance Λ cold dark matter cosmological model and up-to-date competing alternatives, e.g., dynamical dark energy (DE) models or modified gravity (MG) theories. Our method consists of using the weak-lensing magnification effect that affects a standard-siren signal because of its traveling through the Universe's large scale structure. As a demonstration, we present constraints on DE and MG from proposed gravitational-wave detectors, namely Einstein Telescope and DECI-Hertz Interferometer Gravitational-Wave Observatory and Big-Bang Observer.

Testing the generality of the zoom-lens model: Evidence for visual-pathway specific effects of attended-region size on perception.

PubMed

Goodhew, Stephanie C; Lawrence, Rebecca K; Edwards, Mark

2017-05-01

There are volumes of information available to process in visual scenes. Visual spatial attention is a critically important selection mechanism that prevents these volumes from overwhelming our visual system's limited-capacity processing resources. We were interested in understanding the effect of the size of the attended area on visual perception. The prevailing model of attended-region size across cognition, perception, and neuroscience is the zoom-lens model. This model stipulates that the magnitude of perceptual processing enhancement is inversely related to the size of the attended region, such that a narrow attended-region facilitates greater perceptual enhancement than a wider region. Yet visual processing is subserved by two major visual pathways (magnocellular and parvocellular) that operate with a degree of independence in early visual processing and encode contrasting visual information. Historically, testing of the zoom-lens has used measures of spatial acuity ideally suited to parvocellular processing. This, therefore, raises questions about the generality of the zoom-lens model to different aspects of visual perception. We found that while a narrow attended-region facilitated spatial acuity and the perception of high spatial frequency targets, it had no impact on either temporal acuity or the perception of low spatial frequency targets. This pattern also held up when targets were not presented centrally. This supports the notion that visual attended-region size has dissociable effects on magnocellular versus parvocellular mediated visual processing.

Weak lensing magnification in the Dark Energy Survey Science Verification data

NASA Astrophysics Data System (ADS)

Garcia-Fernandez, M.; Sanchez, E.; Sevilla-Noarbe, I.; Suchyta, E.; Huff, E. M.; Gaztanaga, E.; Aleksić, J.; Ponce, R.; Castander, F. J.; Hoyle, B.; Abbott, T. M. C.; Abdalla, F. B.; Allam, S.; Annis, J.; Benoit-Lévy, A.; Bernstein, G. M.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Crocce, M.; Cunha, C. E.; D'Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Eifler, T. F.; Evrard, A. E.; Fernandez, E.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gerdes, D. W.; Giannantonio, T.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; James, D. J.; Jarvis, M.; Kirk, D.; Krause, E.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Lima, M.; MacCrann, N.; Maia, M. A. G.; March, M.; Marshall, J. L.; Melchior, P.; Miquel, R.; Mohr, J. J.; Plazas, A. A.; Romer, A. K.; Roodman, A.; Rykoff, E. S.; Scarpine, V.; Schubnell, M.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Tarle, G.; Thomas, D.; Walker, A. R.; Wester, W.; DES Collaboration

2018-05-01

In this paper, the effect of weak lensing magnification on galaxy number counts is studied by cross-correlating the positions of two galaxy samples, separated by redshift, using the Dark Energy Survey Science Verification data set. This analysis is carried out for galaxies that are selected only by its photometric redshift. An extensive analysis of the systematic effects, using new methods based on simulations is performed, including a Monte Carlo sampling of the selection function of the survey.

Fast T1 and T2 mapping methods: the zoomed U-FLARE sequence compared with EPI and snapshot-FLASH for abdominal imaging at 11.7 Tesla.

PubMed

Pastor, Géraldine; Jiménez-González, María; Plaza-García, Sandra; Beraza, Marta; Reese, Torsten

2017-06-01

A newly adapted zoomed ultrafast low-angle RARE (U-FLARE) sequence is described for abdominal imaging applications at 11.7 Tesla and compared with the standard echo-plannar imaging (EPI) and snapshot fast low angle shot (FLASH) methods. Ultrafast EPI and snapshot-FLASH protocols were evaluated to determine relaxation times in phantoms and in the mouse kidney in vivo. Owing to their apparent shortcomings, imaging artefacts, signal-to-noise ratio (SNR), and variability in the determination of relaxation times, these methods are compared with the newly implemented zoomed U-FLARE sequence. Snapshot-FLASH has a lower SNR when compared with the zoomed U-FLARE sequence and EPI. The variability in the measurement of relaxation times is higher in the Look-Locker sequences than in inversion recovery experiments. Respectively, the average T1 and T2 values at 11.7 Tesla are as follows: kidney cortex, 1810 and 29 ms; kidney medulla, 2100 and 25 ms; subcutaneous tumour, 2365 and 28 ms. This study demonstrates that the zoomed U-FLARE sequence yields single-shot single-slice images with good anatomical resolution and high SNR at 11.7 Tesla. Thus, it offers a viable alternative to standard protocols for mapping very fast parameters, such as T1 and T2, or dynamic processes in vivo at high field.

Signal-to-noise analysis of a birefringent spectral zooming imaging spectrometer

NASA Astrophysics Data System (ADS)

Li, Jie; Zhang, Xiaotong; Wu, Haiying; Qi, Chun

2018-05-01

Study of signal-to-noise ratio (SNR) of a novel spectral zooming imaging spectrometer (SZIS) based on two identical Wollaston prisms is conducted. According to the theory of radiometry and Fourier transform spectroscopy, we deduce the theoretical equations of SNR of SZIS in spectral domain with consideration of the incident wavelength and the adjustable spectral resolution. An example calculation of SNR of SZIS is performed over 400-1000 nm. The calculation results indicate that SNR with different spectral resolutions of SZIS can be optionally selected by changing the spacing between the two identical Wollaston prisms. This will provide theoretical basis for the design, development and engineering of the developed imaging spectrometer for broad spectrum and SNR requirements.

Coherent x-ray zoom condenser lens for diffractive and scanning microscopy.

PubMed

Kimura, Takashi; Matsuyama, Satoshi; Yamauchi, Kazuto; Nishino, Yoshinori

2013-04-22

We propose a coherent x-ray zoom condenser lens composed of two-stage deformable Kirkpatrick-Baez mirrors. The lens delivers coherent x-rays with a controllable beam size, from one micrometer to a few tens of nanometers, at a fixed focal position. The lens is suitable for diffractive and scanning microscopy. We also propose non-scanning coherent diffraction microscopy for extended objects by using an apodized focused beam produced by the lens with a spatial filter. The proposed apodized-illumination method will be useful in highly efficient imaging with ultimate storage ring sources, and will also open the way to single-shot coherent diffraction microscopy of extended objects with x-ray free-electron lasers.

Animated Optical Microscope Zoom in from Phoenix Launch to Martian Surface

NASA Technical Reports Server (NTRS)

2008-01-01

[figure removed for brevity, see original site] Click on image for animation

This animated camera view zooms in from NASA's Phoenix Mars Lander launch site all the way to Phoenix's Microscopy and Electrochemistry and C Eonductivity Analyzer (MECA) aboard the spacecraft on the Martian surface. The final frame shows the soil sample delivered to MECA as viewed through the Optical Microscope (OM) on Sol 17 (June 11, 2008), or the 17th Martian day.

The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

Exploring the Use of Multimedia Fate and Bioaccumulation Models to Calculate Trophic Magnification Factors (TMFs)

EPA Science Inventory

The trophic magnification factor (TMF) is considered to be a key metric for assessing the bioaccumulation potential of organic chemicals in food webs. Fugacity is an equilibrium criterion and thus reflects the relative thermodynamic status of a chemical in the environment and in ...

Influence of magnification and superimposition of structures on cephalometric diagnosis.

PubMed

Paula, Leonardo Koerich de; Solon-de-Mello, Priscilla de Almeida; Mattos, Claudia Trindade; Ruellas, Antônio Carlos de Oliveira; Sant'Anna, Eduardo Franzotti

2015-01-01

The purpose of this study was to assess the influence of magnification and superimposition of structures on CBCT-generated lateral cephalometric radiographs (LCR) using different segments of the cranium. CBCT scans of 10 patients were selected. Four LCR were generated using Dolphin Imaging(r) software: full-face, right side, left side and center of the head. A total of 40 images were imported into Radiocef Studio 2(r), and the angles of the most common cephalometric analyses were traced by the same observer twice and within a 10-day interval. Statistical analyses included intraexaminer agreement and comparison between methods by means of intraclass correlation coefficient (ICC) and Bland-Altman agreement tests. Intraexaminer agreement of the angles assessed by ICC was excellent (> 0.90) for 83% of measurements, good (between 0.75 and 0.90) for 15%, and moderate (between 0.50 and 0.75) for 2% of measurements. The comparison between methods by ICC was excellent for 68% of measurements, good for 26%, and moderate for 6%. Variables presenting wider confidence intervals (> 6o) in the Bland-Altman tests, in intraexaminer assessment, were: mandibular incisor angle, maxillary incisor angle, and occlusal plane angle. And in comparison methods the variables with wider confidence interval were: mandibular incisor, maxillary incisor, GoGn, occlusal plane angle, Frankfort horizontal plane (FHP), and CoA. Superimposition of structures seemed to influence the results more than magnification, and neither one of them significantly influenced the measurements. Considerable individual variability may occur, especially for mandibular and maxillary incisors, FHP and occlusal plane.

Determination of Frequency of the Second Mesiobuccal Canal in the Permanent Maxillary First Molar Teeth with Magnification Loupes (× 3.5)

PubMed Central

Hasan, Muhammad; Raza Khan, Farhan

2014-01-01

INTRODUCTION: The mesiobuccal root of the maxillary first molar has generated more research and clinical investigation than any root. An inability to detect and treat a second mesiobuccal (MB2) canal is a reason for endodontic failure in maxillary first molars. Modifications in the endodontic access and detection techniques, along with advancements in illumination and magnification technology, have aided in the location and treatment with the second mesiobuccal canal of maxillary first molars. OBJECTIVE: To determine the frequency of the second mesiobuccal canal in the permanent maxillary first molars with magnification loupes (× 3.5). MATERIALS AND METHODS: A total of 53 teeth were assessed using a moderate magnification for second mesiobuccal canal in mesiobuccal root of first permanent maxillary molars in vivo. Detection of this canal in maxillary first molars was done through a clinical access cavity preparation under magnification loupes (× 3.5). Data was analyzed using SPSS 15.0. Frequency distribution of variables was determined and the level of significance was kept at 0.05. RESULTS: We were able to detect second mesiobuccal canal in 27 out of 53 (50.9%) of the permanent maxillary first molars that were studied. It was found that the males tend to have a higher proportion of second mesiobuccal canals (up to 31%) as compared to the females in whom the second mesiobuccal canals could be identified only 19% of the time. Whilst, there was no association found between age, gender and chamber obliteration with the presence of second mesiobuccal canal. CONCLUSIONS: In conclusion, within its limitations, this study suggested that the use of magnification loupes enhanced both the detection (50.9%) and negotiation (86.8%) of the second mesiobuccal canals in the permanent maxillary first molars beyond what could be achieved with naked eye. PMID:25324702

3D display for enhanced tele-operation and other applications

NASA Astrophysics Data System (ADS)

Edmondson, Richard; Pezzaniti, J. Larry; Vaden, Justin; Hyatt, Brian; Morris, James; Chenault, David; Bodenhamer, Andrew; Pettijohn, Bradley; Tchon, Joe; Barnidge, Tracy; Kaufman, Seth; Kingston, David; Newell, Scott

2010-04-01

In this paper, we report on the use of a 3D vision field upgrade kit for TALON robot consisting of a replacement flat panel stereoscopic display, and multiple stereo camera systems. An assessment of the system's use for robotic driving, manipulation, and surveillance operations was conducted. A replacement display, replacement mast camera with zoom, auto-focus, and variable convergence, and a replacement gripper camera with fixed focus and zoom comprise the upgrade kit. The stereo mast camera allows for improved driving and situational awareness as well as scene survey. The stereo gripper camera allows for improved manipulation in typical TALON missions.

NEW DEVELOPMENTS ON INVERSE POLYGON MAPPING TO CALCULATE GRAVITATIONAL LENSING MAGNIFICATION MAPS: OPTIMIZED COMPUTATIONS

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

Mediavilla, E.; Lopez, P.; Mediavilla, T.

2011-11-01

We derive an exact solution (in the form of a series expansion) to compute gravitational lensing magnification maps. It is based on the backward gravitational lens mapping of a partition of the image plane in polygonal cells (inverse polygon mapping, IPM), not including critical points (except perhaps at the cell boundaries). The zeroth-order term of the series expansion leads to the method described by Mediavilla et al. The first-order term is used to study the error induced by the truncation of the series at zeroth order, explaining the high accuracy of the IPM even at this low order of approximation.more » Interpreting the Inverse Ray Shooting (IRS) method in terms of IPM, we explain the previously reported N {sup -3/4} dependence of the IRS error with the number of collected rays per pixel. Cells intersected by critical curves (critical cells) transform to non-simply connected regions with topological pathologies like auto-overlapping or non-preservation of the boundary under the transformation. To define a non-critical partition, we use a linear approximation of the critical curve to divide each critical cell into two non-critical subcells. The optimal choice of the cell size depends basically on the curvature of the critical curves. For typical applications in which the pixel of the magnification map is a small fraction of the Einstein radius, a one-to-one relationship between the cell and pixel sizes in the absence of lensing guarantees both the consistence of the method and a very high accuracy. This prescription is simple but very conservative. We show that substantially larger cells can be used to obtain magnification maps with huge savings in computation time.« less

Piercing Ear Keloid: Excision Using Loupe Magnification and Topical Liquid Silicone Gel as Adjuvant

PubMed Central

Ramesh, Bellam A.; Mohan, J.

2018-01-01

Background: Keloid is an abnormal growth of scar at the site of skin injury, which usually does not regress. It proliferates beyond the original scar. The ear keloid usually develops after piercing injury to wear ornaments. A patient usually asks for removal of keloid, as it is aesthetically unpleasant. Patient may sometimes complain of itching and pain. Aim: The study was conducted to analyze results following excision of keloid with its tract and topical silicone gel as the postsurgical adjuvant. Materials and Methods: Ear keloids measuring less than 0.5cm or more than 5cm in maximum dimension were excluded from the study. Nonpiercing causes such as burns, trauma, and recurrent keloid were excluded from the study. The study was carried out on 22 patients who had keloid because of piercing injury, including 4 cases with both ear keloids. Of 26 ear keloids, 19 had the tract or connecting tissue. The lesion was excised under anesthesia using magnification. For all the operated cases, topical liquid silicone gel was used as postsurgical adjuvant therapy. The method of application of topical silicone gel was taught to each patient and was considered significant. Result: The magnification helped in identification of tract in 73% of the cases in this study. Twenty patients had successfully responded to proposed treatment, and two patients developed recurrence while using topical silicone gel as the adjuvant. These two patients were managed with conventional triamcinolone injection. Conclusion: The topical silicone gel as postsurgical adjuvant therapy avoided the use of painful postsurgical injection or radiotherapy for the 1–3cm primary ear keloids. The advantages of magnification were better clearance of keloid tissue, easier identification of tract and removal of keloid pseudopods, meticulous suturing, and comfortable elevation of a small local flap. PMID:29731586

Concentrations and trophic magnification of polychlorinated naphthalenes (PCNs) in marine fish from the Bohai coastal area, China.

PubMed

Cui, Lili; Wang, Shasha; Gao, Lirong; Huang, Huiting; Xia, Dan; Qiao, Lin; Liu, Wenbin

2018-03-01

Polychlorinated naphthalenes (PCNs) have been found widely in the aquatic environment and can be transferred through food chains, which can magnify or dilute their toxic effects on humans. In this study, PCNs were analyzed in samples of 17 species of fish with different dietary habits collected in the Bohai coastal area in China. Dichloronaphthalenes, which have rarely been quantified in previous studies, were determined. The total PCN concentrations were from 7.3 to 214 pg/g wet weight, and the highest concentration was found in ditrema. The trichloronaphthalenes were the most abundant PCNs, followed by the dichloronaphthalenes and pentachloronaphthalenes. The relatively high contributions of the less-chlorinated homologs to the total PCN concentrations indicated that the main PCN sources around the Bohai were industrial thermal process emissions rather than technical PCN formulations. The trophic magnification factors of the PCN homologs were from 3.1 to 9.9, indicating that PCNs were biomagnified by fish. The trophic magnification factor of dichloronaphthalene and trichloronaphthalenes was 5.8 and 6.4, respectively, indicating for the first time that dichloronaphthalene and trichloronaphthalenes can undergo trophic magnification by fish. The two highest trophic magnification factors were for the pentachloronaphthalenes and hexachloronaphthalenes, probably because these PCNs having fewer vicinal carbon atoms without chlorine atoms attached are less easily biotransformed than the other homologs. The dioxin-like toxicities of the PCNs in the samples, expressed as potential toxic equivalences (TEQs), were assessed. The highest total TEQ was 0.0090 pg/g ww, in Pacific herring, and the hexachloronaphthalenes were the dominant contributors to the total TEQs in the fish samples. The PCN TEQs were much lower than the polychlorinated dibenzo-p-dioxin and dibenzofuran and dioxin-like polychlorinated biphenyl TEQs found in fish from the Bohai in previous studies, and

Visual acuity and magnification devices in dentistry.

PubMed

Perrin, Philippe; Eichenberger, Martina; Neuhaus, Klaus W; Lussi, Adrian

2016-01-01

This review discusses visual acuity in dentistry and the influence of optical aids. Studies based on objective visual tests at a dental working distance were included. These studies show dramatic individual variation independent of the dentists’ age. The limitations due to presbyopia begin at an age of 40 years. Dental professionals should have their near vision tested regularly. Visual deficiencies can be compensated with magnification aids. It is important to differentiate between Galilean and Keplerian loupes. The lightweight Galilean loupes allow an almost straight posture and offer improved ergonomics. Younger dentists profit more from the ergonomic aspects, while dentists over the age of 40 can compensate their age-related visual deficiencies when using this type of loupe. Keplerian loupes, with their superior optical construction, improve the visual performance for dentists of all age groups. The optical advantages come at the cost of ergonomic constraints due to the weight of these loupes. The microscope is highly superior visually and ergonomically, and it is indispensable for the visual control of endodontic treatments.

Magnification of starting torques of dc motors by maximum power point trackers in photovoltaic systems

NASA Technical Reports Server (NTRS)

Appelbaum, Joseph; Singer, S.

1989-01-01

Direct current (dc) motors are used in terrestrial photovoltaic (PV) systems such as in water-pumping systems for irrigation and water supply. Direct current motors may also be used for space applications. Simple and low weight systems including dc motors may be of special interest in space where the motors are directly coupled to the solar cell array (with no storage). The system will operate only during times when sufficient insolation is available. An important performance characteristic of electric motors is the starting to rated torque ratio. Different types of dc motors have different starting torque ratios. These ratios are dictated by the size of solar cell array, and the developed motor torque may not be sufficient to overcome the load starting torque. By including a maximum power point tracker (MPPT) in the PV system, the starting to rated torque ratio will increase, the amount of which depends on the motor type. The starting torque ratio is calculated for the permanent magnet, series and shunt excited dc motors when powered by solar cell arrays for two cases: with and without MPPT's. Defining a motor torque magnification by the ratio of the motor torque with an MPPT to the motor torque without an MPPT, a magnification of 3 was obtained for the permanent magnet motor and a magnification of 7 for both the series and shunt motors. The effect of the variation of solar insolation on the motor starting torque was covered. All motor types are less sensitive to insolation variation in systems including MPPT's as compared to systems with MPPT's. The analysis of this paper will assist the PV system designed to determine whether or not to include an MPPT in the system for a specific motor type.

Concurrent image-based visual servoing with adaptive zooming for non-cooperative rendezvous maneuvers

NASA Astrophysics Data System (ADS)

Pomares, Jorge; Felicetti, Leonard; Pérez, Javier; Emami, M. Reza

2018-02-01

An image-based servo controller for the guidance of a spacecraft during non-cooperative rendezvous is presented in this paper. The controller directly utilizes the visual features from image frames of a target spacecraft for computing both attitude and orbital maneuvers concurrently. The utilization of adaptive optics, such as zooming cameras, is also addressed through developing an invariant-image servo controller. The controller allows for performing rendezvous maneuvers independently from the adjustments of the camera focal length, improving the performance and versatility of maneuvers. The stability of the proposed control scheme is proven analytically in the invariant space, and its viability is explored through numerical simulations.

Grating angle magnification enhanced angular sensor and scanner

NASA Technical Reports Server (NTRS)

Sun, Ke-Xun (Inventor); Byer, Robert L. (Inventor)

2009-01-01

An angular magnification effect of diffraction is exploited to provide improved sensing and scanning. This effect is most pronounced for a normal or near-normal incidence angle in combination with a grazing diffraction angle, so such configurations are preferred. Angular sensitivity can be further enhanced because the width of the diffracted beam can be substantially less than the width of the incident beam. Normal incidence configurations with two symmetric diffracted beams are preferred, since rotation and vertical displacement can be readily distinguished. Increased sensitivity to vertical displacement can be provided by incorporating an interferometer into the measurement system. Quad cell detectors can be employed to provide sensitivity to rotation about the grating surface normal. A 2-D grating can be employed to provide sensitivity to angular displacements in two different planes (e.g., pitch and yaw). Combined systems can provide sensitivity to vertical displacement and to all three angular degrees of freedom.

Dynamic calibration of pan-tilt-zoom cameras for traffic monitoring.

PubMed

Song, Kai-Tai; Tai, Jen-Chao

2006-10-01

Pan-tilt-zoom (PTZ) cameras have been widely used in recent years for monitoring and surveillance applications. These cameras provide flexible view selection as well as a wider observation range. This makes them suitable for vision-based traffic monitoring and enforcement systems. To employ PTZ cameras for image measurement applications, one first needs to calibrate the camera to obtain meaningful results. For instance, the accuracy of estimating vehicle speed depends on the accuracy of camera calibration and that of vehicle tracking results. This paper presents a novel calibration method for a PTZ camera overlooking a traffic scene. The proposed approach requires no manual operation to select the positions of special features. It automatically uses a set of parallel lane markings and the lane width to compute the camera parameters, namely, focal length, tilt angle, and pan angle. Image processing procedures have been developed for automatically finding parallel lane markings. Interesting experimental results are presented to validate the robustness and accuracy of the proposed method.

Zooming in on cirrus with the Canadian Regional Climate Model

NASA Astrophysics Data System (ADS)

Stefanof, C.; Stefanof, A.; Beaulne, A.; Munoz Alpizar, R.; Szyrmer, W.; Blanchet, J.

2004-05-01

The Canadian Regional Climate Model plus a microphysical scheme: two-moments microphysics with three hydrometeor categories (cloud liquid water, pristine ice crystals and larger precipitation crystals) is used to test the simulation in forecast mode using ECMWF data at 0.4 X 0.4 degree. We are zooming in on cirrus at higher resolutions (9, 1.8, 0.36 km). We are currently using the data set measured in APEX-E3, measurements of radar, lidar, passive instruments and interpreted microphysics for some flights (G-II, C404, B200). The radar and lidar data are available for high level cirrus. The south west of Japon is the flight region. The dates are March 20, March 27 and April 2, 2003. We first focus on the March 27 frontal system. We did a rigorous synoptical analysis for the cases. The cirrus at 360 m resolution are simulated. The cloud structure and some similarities between model simulation and observations will be presented.

Nonintrusive iris image acquisition system based on a pan-tilt-zoom camera and light stripe projection

NASA Astrophysics Data System (ADS)

Yoon, Soweon; Jung, Ho Gi; Park, Kang Ryoung; Kim, Jaihie

2009-03-01

Although iris recognition is one of the most accurate biometric technologies, it has not yet been widely used in practical applications. This is mainly due to user inconvenience during the image acquisition phase. Specifically, users try to adjust their eye position within small capture volume at a close distance from the system. To overcome these problems, we propose a novel iris image acquisition system that provides users with unconstrained environments: a large operating range, enabling movement from standing posture, and capturing good-quality iris images in an acceptable time. The proposed system has the following three contributions compared with previous works: (1) the capture volume is significantly increased by using a pan-tilt-zoom (PTZ) camera guided by a light stripe projection, (2) the iris location in the large capture volume is found fast due to 1-D vertical face searching from the user's horizontal position obtained by the light stripe projection, and (3) zooming and focusing on the user's irises at a distance are accurate and fast using the estimated 3-D position of a face by the light stripe projection and the PTZ camera. Experimental results show that the proposed system can capture good-quality iris images in 2.479 s on average at a distance of 1.5 to 3 m, while allowing a limited amount of movement by the user.

Ultrafast electrical spectrum analyzer based on all-optical Fourier transform and temporal magnification.

PubMed

Duan, Yuhua; Chen, Liao; Zhou, Haidong; Zhou, Xi; Zhang, Chi; Zhang, Xinliang

2017-04-03

Real-time electrical spectrum analysis is of great significance for applications involving radio astronomy and electronic warfare, e.g. the dynamic spectrum monitoring of outer space signal, and the instantaneous capture of frequency from other electronic systems. However, conventional electrical spectrum analyzer (ESA) has limited operation speed and observation bandwidth due to the electronic bottleneck. Therefore, a variety of photonics-assisted methods have been extensively explored due to the bandwidth advantage of the optical domain. Alternatively, we proposed and experimentally demonstrated an ultrafast ESA based on all-optical Fourier transform and temporal magnification in this paper. The radio-frequency (RF) signal under test is temporally multiplexed to the spectrum of an ultrashort pulse, thus the frequency information is converted to the time axis. Moreover, since the bandwidth of this ultrashort pulse is far beyond that of the state-of-the-art photo-detector, a temporal magnification system is applied to stretch the time axis, and capture the RF spectrum with 1-GHz resolution. The observation bandwidth of this ultrafast ESA is over 20 GHz, limited by that of the electro-optic modulator. Since all the signal processing is in the optical domain, the acquisition frame rate can be as high as 50 MHz. This ultrafast ESA scheme can be further improved with better dispersive engineering, and is promising for some ultrafast spectral information acquisition applications.

Preparing and Restoring Composite Resin Restorations. The Advantage of High Magnification Loupes or the Dental Surgical Operating Microscope.

PubMed

Mamoun, John

2015-01-01

Use of magnification, such as 6x to 8x binocular surgical loupes or the surgical operating microscope, combined with co-axial illumination, may facilitate the creation of stable composite resin restorations that are less likely to develop caries, cracks or margin stains over years of service. Microscopes facilitate observation of clinically relevant microscopic visual details, such as microscopic amounts of demineralization or caries at preparation margins; microscopic areas of soft, decayed tooth structure; microscopic amounts of moisture contamination of the preparation during bonding; or microscopic marginal gaps in the composite. Preventing microscope-level errors in composite fabrication can result in a composite restoration that, at initial placement, appears perfect when viewed under 6x to 8x magnification and which also is free of secondary caries, marginal staining or cracks at multi-year follow-up visits.

New method: calculation of magnification factor from an intracardiac marker.

PubMed

Cha, S D; Incarvito, J; Maranhao, V

1983-01-01

In order to calculate a magnification factor (MF), an intracardiac marker (pigtail catheter with markers) was evaluated using a new formula and correlated with the conventional grid method. By applying the Pythagorean theorem and trigonometry, a new formula was developed, which is (formula; see text) In an experimental study, MF by the intracardiac markers was 0.71 +/- 0.15 (M +/- SD) and one by the grid method was 0.72 +/- 0.15, with a correlation coefficient of 0.96. In patients study, MF by the intracardiac markers was 0.77 +/- 0.06 and one by the grid method was 0.77 +/- 0.05. We conclude that this new method is simple and the results were comparable to the conventional grid method at mid-chest level.

Pain-Related Rumination, But Not Magnification or Helplessness, Mediates Race and Sex Differences in Experimental Pain.

PubMed

Meints, Samantha M; Stout, Madison; Abplanalp, Samuel; Hirsh, Adam T

2017-03-01

Compared with white individuals and men, black individuals and women show a lower tolerance for experimental pain stimuli. Previous studies suggest that pain catastrophizing is important in this context, but little is known about which components of catastrophizing contribute to these race and sex differences. The purpose of the current study was to examine the individual components of catastrophizing (rumination, magnification, and helplessness) as candidate mediators of race and sex differences in experimental pain tolerance. Healthy undergraduates (N = 172, 74% female, 43.2% black) participated in a cold pressor task and completed a situation-specific version of the Pain Catastrophizing Scale. Black and female participants showed a lower pain tolerance than white (P < .01, d = .70) and male (P < .01, d = .55) participants, respectively. Multiple mediation analyses indicated that these race and sex differences were mediated by the rumination component of catastrophizing (indirect effect = -7.13, 95% confidence interval (CI), -16.20 to -1.96, and 5.75, 95% CI, .81-15.57, respectively) but not by the magnification (95% CI, -2.91 to 3.65 and -1.54 to 1.85, respectively) or helplessness (95% CI, -5.53 to 3.31 and -.72 to 5.38, respectively) components. This study provides new information about race and sex differences in pain and suggests that treatments targeting the rumination component of catastrophizing may help mitigate pain-related disparities. This study suggests that differences in pain-related rumination, but not magnification or helplessness, are important contributors to race and sex differences in the pain experience. Interventions that target this maladaptive cognitive style may help reduce disparities in pain. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

User Friendly Real Time Display

NASA Astrophysics Data System (ADS)

McCarthy, Denise M.; McCracken, Bill

1989-02-01

Real-time viewing of high resolution infrared line scan reconnaissance imagery is greatly facilitated using Honeywell's Real Time Display in conjunction with a D-500 Infrared Reconnaissance System. The Real-Time Display (RTD) provides the capability of on-board review of high resolution infrared imagery using the wide infrared dynamic range of the D-500 infrared receiver to maximum advantage. The scan converter accepts, processes, and displays imagery from four channels of the IR Receiver after formatting by a multiplexer. The scan converter interfaces with a standard RS-170 video monitor. Detailed review and on-board analysis of infrared reconnaissance imagery stored on a videotape is easily accomplished using the many user-friendly features of the RTD. Using a convenient joystick controller, on-screen mode menus, and a moveable cursor, the operator can examine scenes of interest at four different display magnifications using a four step bidirectional zoom. Imagery areas of interest are first noted using the scrolling wide field display mode at 8x reduced display resolution. On noting an area of interest, the imagery can be marked on the tape record for future recovery and a freeze frame mode can be initiated. The operator can then move the cursor to the area of interest and zoom to higher display magnification for 4x, 2x, and lx display resolutions so that the full 4096 x 4096 pixel infrared frame can be matched to the 512 x 512 pixel display frame. At 8x wide field display magnification the full line scanner field of view is displayed at 8x reduced resolution. There are two selectable modes of obtaining this reduced resolution. The operator can use the default method, which averages the signal from an 8 x 8 pixel group, or it is also possible to select the peak signal of the 8 x 8 pixel block to represent the entire block on the display. In this alternate peak-signal display the wide field can be effectively scanned for hot objects which are more likely to be

Inhibition of return in the visual field: the eccentricity effect is independent of cortical magnification.

PubMed

Bao, Yan; Lei, Quan; Fang, Yuan; Tong, Yu; Schill, Kerstin; Pöppel, Ernst; Strasburger, Hans

2013-01-01

Inhibition of return (IOR) as an indicator of attentional control is characterized by an eccentricity effect, that is, the more peripheral visual field shows a stronger IOR magnitude relative to the perifoveal visual field. However, it could be argued that this eccentricity effect may not be an attention effect, but due to cortical magnification. To test this possibility, we examined this eccentricity effect in two conditions: the same-size condition in which identical stimuli were used at different eccentricities, and the size-scaling condition in which stimuli were scaled according to the cortical magnification factor (M-scaling), thus stimuli being larger at the more peripheral locations. The results showed that the magnitude of IOR was significantly stronger in the peripheral relative to the perifoveal visual field, and this eccentricity effect was independent of the manipulation of stimulus size (same-size or size-scaling). These results suggest a robust eccentricity effect of IOR which cannot be eliminated by M-scaling. Underlying neural mechanisms of the eccentricity effect of IOR are discussed with respect to both cortical and subcortical structures mediating attentional control in the perifoveal and peripheral visual field.

Zooming in on aquatic denitrification hot spots

NASA Astrophysics Data System (ADS)

Schultz, Colin

2011-06-01

Inorganic nitrogen is an important resource for marine and aquatic ecosystems, acting as a fertilizer for phytoplankton and aquatic plants. When nitrogen concentrations soar, algae blooms can occur. Subsequently, when the algae blooms die, their decomposition can consume most of the available dissolved oxygen, negatively affecting the ecosystem as a whole. Creeks and streams act as strong controls, regulating downstream nitrogen concentrations, and researchers have been zooming in on hyporheic zones—zones where water flows through the sediment alongside the surface water—as possible hot spots of activity in the nitrogen cycle. Using a stable isotope tracer, Zarnetske et al. tracked the evolution of a nitrogen addition as it flowed through a heavily instrumented gravel bar in Drift Creek, in Oregon. The researchers found that the gravel bar could act as either a source or a sink of inorganic nitrogen, depending on how long it took for the water to make its way through the bar. When the creek water took longer to pass through the hyporheic zone, nitrogen levels were reduced significantly through denitrification, while any water that traveled quickly could have its inorganic nitrogen concentrations increased by nitrification. The authors note that a context-dependent effect of individual hyporheic zones on inorganic nitrogen concentrations could have important implications for attempts to estimate the effects of a watershed on the nitrogen cycle. (Journal of Geophysical Research-Biogeosciences, doi:10.1029/ 2010JG001356, 2011)

Dynamic magnification factors for tree blow-down by powder snow avalanche air blasts

NASA Astrophysics Data System (ADS)

Bartelt, Perry; Bebi, Peter; Feistl, Thomas; Buser, Othmar; Caviezel, Andrin

2018-03-01

We study how short duration powder avalanche blasts can break and overturn tall trees. Tree blow-down is often used to back-calculate avalanche pressure and therefore constrain avalanche flow velocity and motion. We find that tall trees are susceptible to avalanche air blasts because the duration of the air blast is near to the period of vibration of tall trees, both in bending and root-plate overturning. Dynamic magnification factors for bending and overturning failures should therefore be considered when back-calculating avalanche impact pressures.

Effects of magnification and visual accommodation on aimpoint estimation in simulated landings with real and virtual image displays

NASA Technical Reports Server (NTRS)

Randle, R. J.; Roscoe, S. N.; Petitt, J. C.

1980-01-01

Twenty professional pilots observed a computer-generated airport scene during simulated autopilot-coupled night landing approaches and at two points (20 sec and 10 sec before touchdown) judged whether the airplane would undershoot or overshoot the aimpoint. Visual accommodation was continuously measured using an automatic infrared optometer. Experimental variables included approach slope angle, display magnification, visual focus demand (using ophthalmic lenses), and presentation of the display as either a real (direct view) or a virtual (collimated) image. Aimpoint judgments shifted predictably with actual approach slope and display magnification. Both pilot judgments and measured accommodation interacted with focus demand with real-image displays but not with virtual-image displays. With either type of display, measured accommodation lagged far behind focus demand and was reliably less responsive to the virtual images. Pilot judgments shifted dramatically from an overwhelming perceived-overshoot bias 20 sec before touchdown to a reliable undershoot bias 10 sec later.

Is the Cortical Deficit in Amblyopia Due to Reduced Cortical Magnification, Loss of Neural Resolution, or Neural Disorganization?

PubMed

Clavagnier, Simon; Dumoulin, Serge O; Hess, Robert F

2015-11-04

The neural basis of amblyopia is a matter of debate. The following possibilities have been suggested: loss of foveal cells, reduced cortical magnification, loss of spatial resolution of foveal cells, and topographical disarray in the cellular map. To resolve this we undertook a population receptive field (pRF) functional magnetic resonance imaging analysis in the central field in humans with moderate-to-severe amblyopia. We measured the relationship between averaged pRF size and retinal eccentricity in retinotopic visual areas. Results showed that cortical magnification is normal in the foveal field of strabismic amblyopes. However, the pRF sizes are enlarged for the amblyopic eye. We speculate that the pRF enlargement reflects loss of cellular resolution or an increased cellular positional disarray within the representation of the amblyopic eye. The neural basis of amblyopia, a visual deficit affecting 3% of the human population, remains a matter of debate. We undertook the first population receptive field functional magnetic resonance imaging analysis in participants with amblyopia and compared the projections from the amblyopic and fellow normal eye in the visual cortex. The projection from the amblyopic eye was found to have a normal cortical magnification factor, enlarged population receptive field sizes, and topographic disorganization in all early visual areas. This is consistent with an explanation of amblyopia as an immature system with a normal complement of cells whose spatial resolution is reduced and whose topographical map is disordered. This bears upon a number of competing theories for the psychophysical defect and affects future treatment therapies. Copyright © 2015 the authors 0270-6474/15/3514740-16$15.00/0.

Search for Low-Mass Exoplanets by Gravitational Microlensing at High Magnification

NASA Astrophysics Data System (ADS)

Abe, F.; Bennett, D. P.; Bond, I. A.; Eguchi, S.; Furuta, Y.; Hearnshaw, J. B.; Kamiya, K.; Kilmartin, P. M.; Kurata, Y.; Masuda, K.; Matsubara, Y.; Muraki, Y.; Noda, S.; Okajima, K.; Rakich, A.; Rattenbury, N. J.; Sako, T.; Sekiguchi, T.; Sullivan, D. J.; Sumi, T.; Tristram, P. J.; Yanagisawa, T.; Yock, P. C. M.; Gal-Yam, A.; Lipkin, Y.; Maoz, D.; Ofek, E. O.; Udalski, A.; Szewczyk, O.; Żebruń, K.; Soszyński, I.; Szymański, M. K.; Kubiak, M.; Pietrzyński, G.; Wyrzykowski, L.

2004-08-01

Observations of the gravitational microlensing event MOA 2003-BLG-32/OGLE 2003-BLG-219 are presented, for which the peak magnification was over 500, the highest yet reported. Continuous observations around the peak enabled a sensitive search for planets orbiting the lens star. No planets were detected. Planets 1.3 times heavier than Earth were excluded from more than 50% of the projected annular region from approximately 2.3 to 3.6 astronomical units surrounding the lens star, Uranus-mass planets were excluded from 0.9 to 8.7 astronomical units, and planets 1.3 times heavier than Saturn were excluded from 0.2 to 60 astronomical units. These are the largest regions of sensitivity yet achieved in searches for extrasolar planets orbiting any star.

Search for low-mass exoplanets by gravitational microlensing at high magnification.

PubMed

Abe, F; Bennett, D P; Bond, I A; Eguchi, S; Furuta, Y; Hearnshaw, J B; Kamiya, K; Kilmartin, P M; Kurata, Y; Masuda, K; Matsubara, Y; Muraki, Y; Noda, S; Okajima, K; Rakich, A; Rattenbury, N J; Sako, T; Sekiguchi, T; Sullivan, D J; Sumi, T; Tristram, P J; Yanagisawa, T; Yock, P C M; Gal-Yam, A; Lipkin, Y; Maoz, D; Ofek, E O; Udalski, A; Szewczyk, O; Zebrun, K; Soszynski, I; Szymanski, M K; Kubiak, M; Pietrzynski, G; Wyrzykowski, L

2004-08-27

Observations of the gravitational microlensing event MOA 2003-BLG-32/OGLE 2003-BLG-219 are presented, for which the peak magnification was over 500, the highest yet reported. Continuous observations around the peak enabled a sensitive search for planets orbiting the lens star. No planets were detected. Planets 1.3 times heavier than Earth were excluded from more than 50% of the projected annular region from approximately 2.3 to 3.6 astronomical units surrounding the lens star, Uranus-mass planets were excluded from 0.9 to 8.7 astronomical units, and planets 1.3 times heavier than Saturn were excluded from 0.2 to 60 astronomical units. These are the largest regions of sensitivity yet achieved in searches for extrasolar planets orbiting any star.

The Effects of Visual Magnification and Physical Movement Scale on the Manipulation of a Tool with Indirect Vision

ERIC Educational Resources Information Center

Bohan, Michael; McConnell, Daniel S.; Chaparro, Alex; Thompson, Shelby G.

2010-01-01

Modern tools often separate the visual and physical aspects of operation, requiring users to manipulate an instrument while viewing the results indirectly on a display. This can pose usability challenges particularly in applications, such as laparoscopic surgery, that require a high degree of movement precision. Magnification used to augment the…

Trophic magnification of organic chemicals: A global synthesis

USGS Publications Warehouse

Walters, David; Jardine, T.D.; Cade, Brian S.; Kidd, K.A.; Muir, D.C.G.; Leipzig-Scott, Peter C.

2016-01-01

Production of organic chemicals (OCs) is increasing exponentially, and some OCs biomagnify through food webs to potentially toxic levels. Biomagnification under field conditions is best described by trophic magnification factors (TMFs; per trophic level change in log-concentration of a chemical) which have been measured for more than two decades. Syntheses of TMF behavior relative to chemical traits and ecosystem properties are lacking. We analyzed >1500 TMFs to identify OCs predisposed to biomagnify and to assess ecosystem vulnerability. The highest TMFs were for OCs that are slowly metabolized by animals (metabolic rate kM < 0.01 day–1) and are moderately hydrophobic (log KOW 6–8). TMFs were more variable in marine than freshwaters, unrelated to latitude, and highest in food webs containing endotherms. We modeled the probability that any OC would biomagnify as a combined function of KOW and kM. Probability is greatest (∼100%) for slowly metabolized compounds, regardless of KOW, and lowest for chemicals with rapid transformation rates (kM > 0.2 day–1). This probabilistic model provides a new global tool for screening existing and new OCs for their biomagnification potential.

GERLUMPH DATA RELEASE 1: HIGH-RESOLUTION COSMOLOGICAL MICROLENSING MAGNIFICATION MAPS AND eResearch TOOLS

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

Vernardos, G.; Fluke, C. J.; Croton, D.

2014-03-01

As synoptic all-sky surveys begin to discover new multiply lensed quasars, the flow of data will enable statistical cosmological microlensing studies of sufficient size to constrain quasar accretion disk and supermassive black hole properties. In preparation for this new era, we are undertaking the GPU-Enabled, High Resolution cosmological MicroLensing parameter survey (GERLUMPH). We present here the GERLUMPH Data Release 1, which consists of 12,342 high resolution cosmological microlensing magnification maps and provides the first uniform coverage of the convergence, shear, and smooth matter fraction parameter space. We use these maps to perform a comprehensive numerical investigation of the mass-sheet degeneracy,more » finding excellent agreement with its predictions. We study the effect of smooth matter on microlensing induced magnification fluctuations. In particular, in the minima and saddle-point regions, fluctuations are enhanced only along the critical line, while in the maxima region they are always enhanced for high smooth matter fractions (≈0.9). We describe our approach to data management, including the use of an SQL database with a Web interface for data access and online analysis, obviating the need for individuals to download large volumes of data. In combination with existing observational databases and online applications, the GERLUMPH archive represents a fundamental component of a new microlensing eResearch cloud. Our maps and tools are publicly available at http://gerlumph.swin.edu.au/.« less

Complete description of the optical path difference of a novel spectral zooming imaging spectrometer

NASA Astrophysics Data System (ADS)

Li, Jie; Wu, Haiying; Qi, Chun

2018-03-01

A complete description of the optical path difference of a novel spectral zooming imaging spectrometer (SZIS) is presented. SZIS is designed based on two identical Wollaston prisms with an adjustable air gap. Thus, interferogram with arbitrary spectral resolution and great reduction of spectral image size can be conveniently formed to adapt to different application requirements. Ray tracing modeling in arbitrary incidence with a quasi-parallel-plate approximation scheme is proposed to analyze the optical path difference of SZIS. In order to know the characteristics of the apparatus, exact calculations of the corresponding spectral resolution and field of view are both derived and analyzed in detail. We also present a comparison of calculation and experiment to prove the validity of the theory.

Personality and defensive reactions: fear, trait anxiety, and threat magnification.

PubMed

Perkins, Adam M; Cooper, Andrew; Abdelall, Maura; Smillie, Luke D; Corr, Philip J

2010-06-01

The revised Reinforcement Sensitivity Theory (rRST) of personality (Gray & McNaughton, 2000) maintains that trait individual differences in the operation of defensive systems relate to facets of human personality, most notably anxiety and fear. We investigated this theory in 2 separate studies (total N=270) using a threat scenario research strategy (Blanchard, Hynd, Minke, Minemoto, & Blanchard, 2001). Consistent with rRST, results showed that individuals with high fear questionnaire scores tended to select defensive responses entailing orientation away from threat (e.g., run away) and that fear-prone individuals also tended to perceive threats as magnified. The extent of this threat magnification mediated the positive association observed between fear and orientation away from threat. Overall, results suggest that interindividual variance in defensive reactions is associated with a variety of existing personality constructs but that further research is required to determine the precise relationship between personality and defensive reactions.

A new scheme for stigmatic x-ray imaging with large magnification.

PubMed

Bitter, M; Hill, K W; Delgado-Aparicio, L F; Pablant, N A; Scott, S; Jones, F; Beiersdorfer, P; Wang, E; del Rio, M Sanchez; Caughey, T A; Brunner, J

2012-10-01

This paper describes a new x-ray scheme for stigmatic imaging. The scheme consists of one convex spherically bent crystal and one concave spherically bent crystal. The radii of curvature and Bragg reflecting lattice planes of the two crystals are properly matched to eliminate the astigmatism, so that the conditions for stigmatic imaging are met for a particular wavelength. The magnification is adjustable and solely a function of the two Bragg angles or angles of incidence. Although the choice of Bragg angles is constrained by the availability of crystals, this is not a severe limitation for the imaging of plasmas, since a particular wavelength can be selected from the bremsstrahlung continuum. The working principle of this imaging scheme has been verified with visible light. Further tests with x rays are planned for the near future.

Contactless physiological signals extraction based on skin color magnification

NASA Astrophysics Data System (ADS)

Suh, Kun Ha; Lee, Eui Chul

2017-11-01

Although the human visual system is not sufficiently sensitive to perceive blood circulation, blood flow caused by cardiac activity makes slight changes on human skin surfaces. With advances in imaging technology, it has become possible to capture these changes through digital cameras. However, it is difficult to obtain clear physiological signals from such changes due to its fineness and noise factors, such as motion artifacts and camera sensing disturbances. We propose a method for extracting physiological signals with improved quality from skin colored-videos recorded with a remote RGB camera. The results showed that our skin color magnification method reveals the hidden physiological components remarkably in the time-series signal. A Korea Food and Drug Administration-approved heart rate monitor was used for verifying the resulting signal synchronized with the actual cardiac pulse, and comparisons of signal peaks showed correlation coefficients of almost 1.0. In particular, our method can be an effective preprocessing before applying additional postfiltering techniques to improve accuracy in image-based physiological signal extractions.

Effect of a combination of flip and zooming stimuli on the performance of a visual brain-computer interface for spelling.

PubMed

Cheng, Jiao; Jin, Jing; Daly, Ian; Zhang, Yu; Wang, Bei; Wang, Xingyu; Cichocki, Andrzej

2018-02-13

Brain-computer interface (BCI) systems can allow their users to communicate with the external world by recognizing intention directly from their brain activity without the assistance of the peripheral motor nervous system. The P300-speller is one of the most widely used visual BCI applications. In previous studies, a flip stimulus (rotating the background area of the character) that was based on apparent motion, suffered from less refractory effects. However, its performance was not improved significantly. In addition, a presentation paradigm that used a "zooming" action (changing the size of the symbol) has been shown to evoke relatively higher P300 amplitudes and obtain a better BCI performance. To extend this method of stimuli presentation within a BCI and, consequently, to improve BCI performance, we present a new paradigm combining both the flip stimulus with a zooming action. This new presentation modality allowed BCI users to focus their attention more easily. We investigated whether such an action could combine the advantages of both types of stimuli presentation to bring a significant improvement in performance compared to the conventional flip stimulus. The experimental results showed that the proposed paradigm could obtain significantly higher classification accuracies and bit rates than the conventional flip paradigm (p<0.01).

3D vision upgrade kit for TALON robot

NASA Astrophysics Data System (ADS)

Edmondson, Richard; Vaden, Justin; Hyatt, Brian; Morris, James; Pezzaniti, J. Larry; Chenault, David B.; Tchon, Joe; Barnidge, Tracy; Kaufman, Seth; Pettijohn, Brad

2010-04-01

In this paper, we report on the development of a 3D vision field upgrade kit for TALON robot consisting of a replacement flat panel stereoscopic display, and multiple stereo camera systems. An assessment of the system's use for robotic driving, manipulation, and surveillance operations was conducted. The 3D vision system was integrated onto a TALON IV Robot and Operator Control Unit (OCU) such that stock components could be electrically disconnected and removed, and upgrade components coupled directly to the mounting and electrical connections. A replacement display, replacement mast camera with zoom, auto-focus, and variable convergence, and a replacement gripper camera with fixed focus and zoom comprise the upgrade kit. The stereo mast camera allows for improved driving and situational awareness as well as scene survey. The stereo gripper camera allows for improved manipulation in typical TALON missions.

Blinded evaluation of the effects of high definition and magnification on perceived image quality in laryngeal imaging.

PubMed

Otto, Kristen J; Hapner, Edie R; Baker, Michael; Johns, Michael M

2006-02-01

Advances in commercial video technology have improved office-based laryngeal imaging. This study investigates the perceived image quality of a true high-definition (HD) video camera and the effect of magnification on laryngeal videostroboscopy. We performed a prospective, dual-armed, single-blinded analysis of a standard laryngeal videostroboscopic examination comparing 3 separate add-on camera systems: a 1-chip charge-coupled device (CCD) camera, a 3-chip CCD camera, and a true 720p (progressive scan) HD camera. Displayed images were controlled for magnification and image size (20-inch [50-cm] display, red-green-blue, and S-video cable for 1-chip and 3-chip cameras; digital visual interface cable and HD monitor for HD camera). Ten blinded observers were then asked to rate the following 5 items on a 0-to-100 visual analog scale: resolution, color, ability to see vocal fold vibration, sense of depth perception, and clarity of blood vessels. Eight unblinded observers were then asked to rate the difference in perceived resolution and clarity of laryngeal examination images when displayed on a 10-inch (25-cm) monitor versus a 42-inch (105-cm) monitor. A visual analog scale was used. These monitors were controlled for actual resolution capacity. For each item evaluated, randomized block design analysis demonstrated that the 3-chip camera scored significantly better than the 1-chip camera (p < .05). For the categories of color and blood vessel discrimination, the 3-chip camera scored significantly better than the HD camera (p < .05). For magnification alone, observers rated the 42-inch monitor statistically better than the 10-inch monitor. The expense of new medical technology must be judged against its added value. This study suggests that HD laryngeal imaging may not add significant value over currently available video systems, in perceived image quality, when a small monitor is used. Although differences in clarity between standard and HD cameras may not be readily

Web-based metabolic network visualization with a zooming user interface

PubMed Central

2011-01-01

Background Displaying complex metabolic-map diagrams, for Web browsers, and allowing users to interact with them for querying and overlaying expression data over them is challenging. Description We present a Web-based metabolic-map diagram, which can be interactively explored by the user, called the Cellular Overview. The main characteristic of this application is the zooming user interface enabling the user to focus on appropriate granularities of the network at will. Various searching commands are available to visually highlight sets of reactions, pathways, enzymes, metabolites, and so on. Expression data from single or multiple experiments can be overlaid on the diagram, which we call the Omics Viewer capability. The application provides Web services to highlight the diagram and to invoke the Omics Viewer. This application is entirely written in JavaScript for the client browsers and connect to a Pathway Tools Web server to retrieve data and diagrams. It uses the OpenLayers library to display tiled diagrams. Conclusions This new online tool is capable of displaying large and complex metabolic-map diagrams in a very interactive manner. This application is available as part of the Pathway Tools software that powers multiple metabolic databases including Biocyc.org: The Cellular Overview is accessible under the Tools menu. PMID:21595965

Sensitivity enhanced strain and temperature measurements based on FBG and frequency chirp magnification.

PubMed

Du, Jiangbing; He, Zuyuan

2013-11-04

In this work, highly sensitive measurements of strain and temperature have been demonstrated using a fiber Bragg grating (FBG) sensor with significantly enhance sensitivity by all-optical signal processing. The sensitivity enhancement is achieved by degenerated Four Wave Mixing (FWM) for frequency chirp magnification (FCM), which can be used for magnifying the wavelength drift of the FBG sensor induced by strain and temperature change. Highly sensitive measurements of static strain and temperature have been experimentally demonstrated with strain sensitivity of 5.36 pm/με and temperature sensitivity of 54.09 pm/°C. The sensitivity has been enhanced by a factor of five based on a 4-order FWM in a highly nonlinear fiber (HNLF).

Fast algorithm for chirp transforms with zooming-in ability and its applications.

PubMed

Deng, X; Bihari, B; Gan, J; Zhao, F; Chen, R T

2000-04-01

A general fast numerical algorithm for chirp transforms is developed by using two fast Fourier transforms and employing an analytical kernel. This new algorithm unifies the calculations of arbitrary real-order fractional Fourier transforms and Fresnel diffraction. Its computational complexity is better than a fast convolution method using Fourier transforms. Furthermore, one can freely choose the sampling resolutions in both x and u space and zoom in on any portion of the data of interest. Computational results are compared with analytical ones. The errors are essentially limited by the accuracy of the fast Fourier transforms and are higher than the order 10(-12) for most cases. As an example of its application to scalar diffraction, this algorithm can be used to calculate near-field patterns directly behind the aperture, 0 < or = z < d2/lambda. It compensates another algorithm for Fresnel diffraction that is limited to z > d2/lambdaN [J. Opt. Soc. Am. A 15, 2111 (1998)]. Experimental results from waveguide-output microcoupler diffraction are in good agreement with the calculations.

The Effects of Various Mounting Systems of near Magnification on Reading Performance and Preference in School-Age Students with Low Vision

ERIC Educational Resources Information Center

Lusk, Kelly E.

2012-01-01

This single-subject study explored the effects of different mounting systems of prescribed near magnification (handheld, stand-mounted, spectacle-mounted, and electronic) on reading performance and preference in students with low vision. Participants included five students ranging from 3rd to 11th grade, and with various etiologies. Reading…

Comparison of two methods of visual magnification for removal of adhesive flash during bracket placement using two types of orthodontic bonding agents

PubMed Central

Alencar, Estefania Queiroga de Santana e; Nobrega, Maria de Lourdes Martins; Dametto, Fabio Roberto; dos Santos, Patrícia Bittencourt Dutra; Pinheiro, Fabio Henrique de Sá Leitão

2016-01-01

ABSTRACT Objective: This study aimed to evaluate the effectiveness of two methods of visual magnification (operating microscope and light head magnifying glass) for removal of composite flash around orthodontic metal brackets. Material and Methods: Brackets were bonded in the center of the clinical crown of sixty well-preserved human premolars. Half of the sample was bonded with conventional Transbond XT (3M Unitek TM, USA), whereas the other half was bonded with Transbond TM Plus Color Change (3M Unitek TM, USA). For each type of composite, the choice of method to remove the flash was determined by randomly distributing the teeth into the following subgroups: A (removal by naked eye, n = 10), B (removal with the aid of light head magnifying glass, under 4x magnification, n = 10), and C (removal with the aid of an operating microscope, under 40x magnification, n = 10). Brackets were debonded and teeth taken to a scanning electron microscope (SS-x-550, Shimadzu, Japan) for visualization of their buccal surface. Quantification of composite flash was performed with Image Pro Plus software, and values were compared by Kruskal-Wallis test and Dunn’s post-hoc test at 5% significance level. Results: Removal of pigmented orthodontic adhesive with the aid of light head magnifying glass proved, in general, to be advantageous in comparison to all other methods. Conclusion: There was no advantage in using Transbond TM Plus Color Change alone. Further studies are necessary to draw a more definitive conclusion in regards to the benefits of using an operating microscope. PMID:28125139

High-magnification super-resolution FINCH microscopy using birefringent crystal lens interferometers

NASA Astrophysics Data System (ADS)

Siegel, Nisan; Lupashin, Vladimir; Storrie, Brian; Brooker, Gary

2016-12-01

Fresnel incoherent correlation holography (FINCH) microscopy is a promising approach for high-resolution biological imaging but has so far been limited to use with low-magnification, low-numerical-aperture configurations. We report the use of in-line incoherent interferometers made from uniaxial birefringent α-barium borate (α-BBO) or calcite crystals that overcome the aberrations and distortions present with previous implementations that employed spatial light modulators or gradient refractive index lenses. FINCH microscopy incorporating these birefringent elements and high-numerical-aperture oil immersion objectives could outperform standard wide-field fluorescence microscopy, with, for example, a 149 nm lateral point spread function at a wavelength of 590 nm. Enhanced resolution was confirmed with sub-resolution fluorescent beads. Taking the Golgi apparatus as a biological example, three different proteins labelled with GFP and two other fluorescent dyes in HeLa cells were resolved with an image quality that is comparable to similar samples captured by structured illumination microscopy.

Low vision system for rapid near- and far-field magnification switching.

PubMed

Ambrogi, Nicholas; Dias-Carlson, Rachel; Gantner, Karl; Gururaj, Anisha; Hanumara, Nevan; Narain, Jaya; Winter, Amos; Zielske, Iris; Satgunam, PremNandhini; Bagga, Deepak Kumar; Gothwal, Vijaya

2015-01-01

People suffering from low vision, a condition caused by a variety of eye-related diseases and/or disorders, find their ability to read greatly improved when text is magnified between 2 and 6 times. Assistive devices currently on the market are either geared towards reading text far away (~20 ft.) or very near (~2 ft.). This is a problem especially for students suffering from low vision, as they struggle to flip their focus between the chalkboard (far-field) and their notes (near- field). A solution to this problem is of high interest to eye care facilities in the developing world - no devices currently exist that have the aforementioned capabilities at an accessible price point. Through consultation with specialists at L.V. Prasad Eye Institute in India, the authors propose, design and demonstrate a device that fills this need, directed primarily at the Indian market. The device utilizes available hardware technologies to electronically capture video ahead of the user and zoom and display the image in real-time on LCD screens mounted in front of the user's eyes. This design is integrated as a wearable system in a glasses form-factor.

Determination of Electron Optical Properties for Aperture Zoom Lenses Using an Artificial Neural Network Method.

PubMed

Isik, Nimet

2016-04-01

Multi-element electrostatic aperture lens systems are widely used to control electron or charged particle beams in many scientific instruments. By means of applied voltages, these lens systems can be operated for different purposes. In this context, numerous methods have been performed to calculate focal properties of these lenses. In this study, an artificial neural network (ANN) classification method is utilized to determine the focused/unfocused charged particle beam in the image point as a function of lens voltages for multi-element electrostatic aperture lenses. A data set for training and testing of ANN is taken from the SIMION 8.1 simulation program, which is a well known and proven accuracy program in charged particle optics. Mean squared error results of this study indicate that the ANN classification method provides notable performance characteristics for electrostatic aperture zoom lenses.

The Herschel-ATLAS: magnifications and physical sizes of 500-μm-selected strongly lensed galaxies

NASA Astrophysics Data System (ADS)

Enia, A.; Negrello, M.; Gurwell, M.; Dye, S.; Rodighiero, G.; Massardi, M.; De Zotti, G.; Franceschini, A.; Cooray, A.; van der Werf, P.; Birkinshaw, M.; Michałowski, M. J.; Oteo, I.

2018-04-01

We perform lens modelling and source reconstruction of Sub-millimetre Array (SMA) data for a sample of 12 strongly lensed galaxies selected at 500μm in the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). A previous analysis of the same data set used a single Sérsic profile to model the light distribution of each background galaxy. Here we model the source brightness distribution with an adaptive pixel scale scheme, extended to work in the Fourier visibility space of interferometry. We also present new SMA observations for seven other candidate lensed galaxies from the H-ATLAS sample. Our derived lens model parameters are in general consistent with previous findings. However, our estimated magnification factors, ranging from 3 to 10, are lower. The discrepancies are observed in particular where the reconstructed source hints at the presence of multiple knots of emission. We define an effective radius of the reconstructed sources based on the area in the source plane where emission is detected above 5σ. We also fit the reconstructed source surface brightness with an elliptical Gaussian model. We derive a median value reff ˜ 1.77 kpc and a median Gaussian full width at half-maximum ˜1.47 kpc. After correction for magnification, our sources have intrinsic star formation rates (SFR) ˜ 900-3500 M⊙ yr-1, resulting in a median SFR surface density ΣSFR ˜ 132 M⊙ yr-1 kpc-2 (or ˜218 M⊙ yr-1 kpc-2 for the Gaussian fit). This is consistent with that observed for other star-forming galaxies at similar redshifts, and is significantly below the Eddington limit for a radiation pressure regulated starburst.

Extension of DQE to include scatter, grid, magnification, and focal spot blur: a new experimental technique and metric

NASA Astrophysics Data System (ADS)

Ranger, N. T.; Mackenzie, A.; Honey, I. D.; Dobbins, J. T., III; Ravin, C. E.; Samei, E.

2009-02-01

In digital radiography, conventional DQE evaluations are performed under idealized conditions that do not reflect typical clinical operating conditions. For this reason, we have developed and evaluated an experimental methodology for measuring theeffective detective quantum efficiency (eDQE) of digital radiographic systems and its utility in chest imaging applications.To emulate the attenuation and scatter properties of the human thorax across a range of sizes, the study employed pediatric and adult geometric chest imaging phantoms designed for use in the FDA/CDRH Nationwide Evaluation of X-Ray Trends (NEXT) program and a third phantom configuration designed to represent the bariatric population. The MTF for each phantom configuration was measured using images of an opaque edge device placed at the nominal surface of each phantom and at a common reference point. For each phantom, the NNPS was measured in a uniform region within the phantom image acquired at an exposure level determined from a prior phototimed acquisition. Scatter measurements were made using a beam-stop technique. These quantities were used along with measures of phantom attenuation and estimates of x-ray flux, to compute the eDQE at the beam-entrance surface of the phantoms, reflecting the presence of scatter, grid, magnification, and focal spot blur. The MTF results showed notable degradation due to focal spot blurring enhanced by geometric magnification, with increasing phantom size. Measured scatter fractions were 33%, 34% and 46% for the pediatric, adult, and bariatric phantoms, respectively. Correspondingly, the measured narrow beam transmission fractions were 16%, 9%, and 3%. The eDQE results for the pediatric and adult phantoms correlate well at low spatial frequencies but show degradation in the eDQE at increasing spatial frequencies for the adult phantom in comparison to the pediatric phantom. The results for the bariatric configuration showed a marked decrease in eDQE in comparison to

Application of a Compact High-Definition Exoscope for Illumination and Magnification in High-Precision Surgical Procedures.

PubMed

Krishnan, Kartik G; Schöller, Karsten; Uhl, Eberhard

2017-01-01

The basic necessities for surgical procedures are illumination, exposure, and magnification. These have undergone transformation in par with technology. One of the recent developments is the compact magnifying exoscope system. In this report, we describe the application of this system for surgical operations and discuss its advantages and pitfalls. We used the ViTOM exoscope mounted on the mechanical holding arm. The following surgical procedures were conducted: lumbar and cervical spinal canal decompression (n = 5); laminotomy and removal of lumbar migrated disk herniations (n = 4); anterior cervical diskectomy and fusion (n = 1); removal of intraneural schwannomas (n = 2); removal of an acute cerebellar hemorrhage (n = 1); removal of a parafalcine atypical cerebral hematoma caused by a dural arteriovenous fistula (n = 1); and microsutures and anastomoses of a nerve (n = 1), an artery (n = 1), and veins (n = 2). The exoscope offered excellent, magnified, and brilliantly illuminated high-definition images of the surgical field. All surgical operations were successfully completed. The main disadvantage was the adjustment and refocusing using the mechanical holding arm. The time required for the surgical operation under the exoscope was slightly longer than the times required for a similar procedure performed using an operating microscope. The magnifying exoscope is an effective and nonbulky tool for surgical procedures. In visualization around the corners, the exoscope has better potential than a microscope. With technical and technologic modifications, the exoscope might become the next generation in illumination, visualization, exposure, and magnification for high-precision surgical procedures. Copyright © 2016 Elsevier Inc. All rights reserved.

[An alternative to the usual operating microscope and loupe magnification for free microvascular tissue transfer. Varioscope AF3-A].

PubMed

Chiummariello, S; Alfano, C; Fioramonti, P; Scuderi, N

2005-12-01

Free microvascular tissue transfers have become today a key instrument for the surgical treatment of wide loss of tissue, but their employment implies mandatory use of the right visual magnification means. Until now these instruments were mainly loupes and operating microscopes. Our study is focusing on the use of a new visual system--Varioscope AF3-A--in the reconstructive microsurgery field. Varioscope AF3-A (Life Optics, Vienna, Austria) has been employed in our Institute in 10 microvascular reconstructions, where different free flaps were used in head and neck reconstruction. All the flaps took and only one developed a partial necrosis. We have also noticed, by using this new instrument, a learning curve with a progressive contraction of the operating time. In all cases we have operated on 2 mm caliber vessels or more and on tissues that didn't previously undergo radiation therapy. The employment of a visual magnification mean, as Varioscope AF3-A, allows autofocus (from 3.6X to 7.2X) and a wide vision. It can be easily used with substantial advantages for the surgeon in performing microvascular anastomosis. Partial drawbacks are the equipment high cost and weight, compared to the loupes and a stronger ocular stress due to the continuous autofocus compared to the static operating microscopes.

Clinical magnification and residual refraction after implantation of a double intraocular lens system in patients with macular degeneration.

PubMed

Amselem, Luis; Diaz-Llopis, Manuel; Felipe, Adelina; Artigas, Jose M; Navea, Amparo; García-Delpech, Salvador

2008-09-01

To evaluate the efficacy of a standard double intraocular lens (IOL) system (IOL-Vip) in patients with low vision and central scotoma due to macular degeneration and assess the predictability of the residual refraction and magnification. Ophthalmology Department, Hospital General Universitario, Valencia, Spain. This interventional prospective noncomparative case series comprised 13 consecutive surgical procedures in 10 patients with central scotoma. Follow-up was 12 months. Evaluation included the difference between preoperative and postoperative best corrected visual acuity (BCVA), refraction, position of the IOLs, endothelial cell density, and occurrence of postoperative complications. Residual refraction and eye magnification were calculated using a theory developed in a previous study, and the values were compared with the clinical results. The mean BCVA was 1.37 logMAR preoperatively and 0.68 logMAR 1 year postoperatively. The mean best corrected clinical gain was 44%. There was no statistically significant difference between the clinically evaluated and theoretically calculated residual refractions (P = .17). No intraoperative or postoperative complications occurred. Implantation of the double IOL system improved BCVA in patients with low vision due to advanced maculopathy. The results were best in myopic patients (long eyes); patients with hyperopia (short eyes) had high residual refraction. The postoperative clinical gain and residual refraction were predictable, showing the feasibility of implanting a customized double IOL.

Parafoveal magnification: visual acuity does not modulate the perceptual span in reading.

PubMed

Miellet, Sébastien; O'Donnell, Patrick J; Sereno, Sara C

2009-06-01

Models of eye guidance in reading rely on the concept of the perceptual span-the amount of information perceived during a single eye fixation, which is considered to be a consequence of visual and attentional constraints. To directly investigate attentional mechanisms underlying the perceptual span, we implemented a new reading paradigm-parafoveal magnification (PM)-that compensates for how visual acuity drops off as a function of retinal eccentricity. On each fixation and in real time, parafoveal text is magnified to equalize its perceptual impact with that of concurrent foveal text. Experiment 1 demonstrated that PM does not increase the amount of text that is processed, supporting an attentional-based account of eye movements in reading. Experiment 2 explored a contentious issue that differentiates competing models of eye movement control and showed that, even when parafoveal information is enlarged, visual attention in reading is allocated in a serial fashion from word to word.

Evaluation and Comparison of High-Resolution (HR) and High-Light (HL) Phosphors in the Micro-Angiographic Fluoroscope (MAF) using Generalized Linear Systems Analyses (GMTF, GDQE) that include the Effect of Scatter, Magnification and Detector Characteristics.

PubMed

Gupta, Sandesh K; Jain, Amit; Bednarek, Daniel R; Rudin, Stephen

2011-01-01

In this study, we evaluated the imaging characteristics of the high-resolution, high-sensitivity micro-angiographic fluoroscope (MAF) with 35-micron pixel-pitch when used with different commercially-available 300 micron thick phosphors: the high resolution (HR) and high light (HL) from Hamamatsu. The purpose of this evaluation was to see if the HL phosphor with its higher screen efficiency could be replaced with the HR phosphor to achieve improved resolution without an increase in noise resulting from the HR's decreased light-photon yield. We designated the detectors MAF-HR and MAF-HL and compared them with a standard flat panel detector (FPD) (194 micron pixel pitch and 600 micron thick CsI(Tl)). For this comparison, we used the generalized linear-system metrics of GMTF, GNNPS and GDQE which are more realistic measures of total system performance since they include the effect of scattered radiation, focal spot distribution, and geometric un-sharpness. Magnifications (1.05-1.15) and scatter fractions (0.28 and 0.33) characteristic of a standard head phantom were used. The MAF-HR performed significantly better than the MAF-HL at high spatial frequencies. The ratio of GMTF and GDQE of the MAF-HR compared to the MAF-HL at 3(6) cycles/mm was 1.45(2.42) and 1.23(2.89), respectively. Despite significant degradation by inclusion of scatter and object magnification, both MAF-HR and MAF-HL provide superior performance over the FPD at higher spatial frequencies with similar performance up to the FPD's Nyquist frequency of 2.5 cycles/mm. Both substantially higher resolution and improved GDQE can be achieved with the MAF using the HR phosphor instead of the HL phosphor.

Zoom In! A Nanoscience Claymation Video Project Designed for Students K-3

NASA Astrophysics Data System (ADS)

Sandler, Nancy; Ulloa, Sergio; Raney, Kate

2014-03-01

Nanoscience concepts are somewhat new and strange to the general public, and although simple to explain, have not permeated through the various information channels available for public education. This is particularly true for children. Because young people in levels K-3 are exposed to digital media on a daily basis, we recognized the importance of reaching them using a familiar format. Hence, we developed a claymation Zoom In! movie that follows the ``adventures'' of Gwen Pym, a girl ``nanoscientist,'' in her quest for a dress that cannot be stained. The pilot video presented in this talk provides a novel and imaginative way to capture young children's attention while focusing on basic nanoscience concepts. By reducing Gwen to a sub-milimeter scale, concepts of scale, surface tension, hydrophobicity induced by roughness, are all exemplified in simple terms accessible to this age range. The movie is accompanied by supporting material aimed at schoolteachers, covering the physics concepts involved in the various aspects of the adventure, and including suggested on-class activities that expand on these points. The final product is contained in a DVD that was distributed to the local elementary schools in the South East Ohio area. Supported by the APS Physics on the Road Program.

Design of two-DMD based zoom MW and LW dual-band IRSP using pixel fusion

NASA Astrophysics Data System (ADS)

Pan, Yue; Xu, Xiping; Qiao, Yang

2018-06-01

In order to test the anti-jamming ability of mid-wave infrared (MWIR) and long-wave infrared (LWIR) dual-band imaging system, a zoom mid-wave (MW) and long-wave (LW) dual-band infrared scene projector (IRSP) based on two-digital micro-mirror device (DMD) was designed by using a projection method of pixel fusion. Two illumination systems, which illuminate the two DMDs directly with Kohler telecentric beam respectively, were combined with projection system by a spatial layout way. The distances of projection entrance pupil and illumination exit pupil were also analyzed separately. MWIR and LWIR virtual scenes were generated respectively by two DMDs and fused by a dichroic beam combiner (DBC), resulting in two radiation distributions in projected image. The optical performance of each component was evaluated by ray tracing simulations. Apparent temperature and image contrast were demonstrated by imaging experiments. On the basis of test and simulation results, the aberrations of optical system were well corrected, and the quality of projected image meets test requirements.

Russell body gastritis with Dutcher bodies evaluated using magnification endoscopy

PubMed Central

Yorita, Kenji; Iwasaki, Takehiro; Uchita, Kunihisa; Kuroda, Naoto; Kojima, Koji; Iwamura, Shinichi; Tsutsumi, Yutaka; Ohno, Akinobu; Kataoka, Hiroaki

2017-01-01

Russell body gastritis (RBG) is an unusual type of chronic gastritis characterized by marked infiltration of Mott cells, which are plasma cells filled with spherical eosinophilic bodies referred to as Russell bodies. It was initially thought that Helicobacter pylori (H. pylori) infection was a major cause of RBG and that the infiltrating Mott cells were polyphenotypic; however, a number of cases of RBG without H. pylori infection or with monoclonal Mott cells have been reported. Thus, diagnostic difficulty exists in distinguishing RBG with monoclonal Mott cells from malignant lymphoma. Here, we report an unusual case of an 86-year-old-Japanese man with H. pylori-positive RBG. During the examination of melena, endoscopic evaluation confirmed a 13-mm whitish, flat lesion in the gastric antrum. Magnification endoscopy with narrow-band imaging suggested that the lesion was most likely a poorly differentiated adenocarcinoma. Biopsy findings were consistent with chronic gastritis with many Mott cells with intranuclear inclusions referred to as Dutcher bodies. Endoscopic submucosal dissection confirmed the diagnosis of RBG with kappa-restricted monoclonal Mott cells. Malignant lymphoma was unlikely given the paucity of cytological atypia and Ki-67 immunoreactivity of monoclonal Mott cells. This is the first reported case of RBG with endoscopic diagnosis of malignant tumor and the presence of Dutcher bodies. PMID:28874963

Characterization of the Failure Site Distribution in MIM Devices Using Zoomed Wavelet Analysis

NASA Astrophysics Data System (ADS)

Muñoz-Gorriz, J.; Monaghan, S.; Cherkaoui, K.; Suñé, J.; Hurley, P. K.; Miranda, E.

2018-05-01

The angular wavelet analysis is applied to the study of the spatial distribution of breakdown (BD) spots in Pt/HfO2/Pt capacitors with square and circular areas. The method is originally developed for rectangular areas, so a zoomed approach needs to be considered when the observation window does not coincide with the device area. The BD spots appear as a consequence of the application of electrical stress to the device. The stress generates defects within the dielectric film, a process that ends with the formation of a percolation path between the electrodes and the melting of the top metal layer because of the high release of energy. The BD spots have lateral sizes ranging from 1 μm to 3 μm and they appear as a point pattern that can be studied using spatial statistics methods. In this paper, we report the application of the angular wavelet method as a complementary tool for the analysis of the distribution of failure sites in large-area metal-insulator-metal (MIM) devices. The differences between considering a continuous or a discrete wavelet and the role played by the number of BD spots are also investigated.

A fully automated calibration method for an optical see-through head-mounted operating microscope with variable zoom and focus.

PubMed

Figl, Michael; Ede, Christopher; Hummel, Johann; Wanschitz, Felix; Ewers, Rolf; Bergmann, Helmar; Birkfellner, Wolfgang

2005-11-01

Ever since the development of the first applications in image-guided therapy (IGT), the use of head-mounted displays (HMDs) was considered an important extension of existing IGT technologies. Several approaches to utilizing HMDs and modified medical devices for augmented reality (AR) visualization were implemented. These approaches include video-see through systems, semitransparent mirrors, modified endoscopes, and modified operating microscopes. Common to all these devices is the fact that a precise calibration between the display and three-dimensional coordinates in the patient's frame of reference is compulsory. In optical see-through devices based on complex optical systems such as operating microscopes or operating binoculars-as in the case of the system presented in this paper-this procedure can become increasingly difficult since precise camera calibration for every focus and zoom position is required. We present a method for fully automatic calibration of the operating binocular Varioscope M5 AR for the full range of zoom and focus settings available. Our method uses a special calibration pattern, a linear guide driven by a stepping motor, and special calibration software. The overlay error in the calibration plane was found to be 0.14-0.91 mm, which is less than 1% of the field of view. Using the motorized calibration rig as presented in the paper, we were also able to assess the dynamic latency when viewing augmentation graphics on a mobile target; spatial displacement due to latency was found to be in the range of 1.1-2.8 mm maximum, the disparity between the true object and its computed overlay represented latency of 0.1 s. We conclude that the automatic calibration method presented in this paper is sufficient in terms of accuracy and time requirements for standard uses of optical see-through systems in a clinical environment.

Hip joint replacement

MedlinePlus

... Total hip replacement; Hip hemiarthroplasty; Arthritis - hip replacement; Osteoarthritis - hip replacement ... total hip replacement surgery in patients with hip osteoarthritis: a long-term follow-up of a randomised ...

Optimizing pulse shaping and zooming for acceleration to high velocities and fusion neutron production on the Nike laser

NASA Astrophysics Data System (ADS)

Karasik, Max; Weaver, J. L.; Aglitskiy, Y.; Zalesak, S. T.; Velikovich, A. L.; Oh, J.; Obenschain, S. P.; Arikawa, Y.; Watari, T.

2010-11-01

We will present results from follow-on experiments to the record-high velocities of 1000 km/s achieved on Nike [Karasik et al., Phys. Plasmas 17, 056317 (2010) ], in which highly accelerated planar foils of deuterated polystyrene were made to collide with a witness foil to produce extreme shock pressures and result in heating of matter to thermonuclear temperatures. Still higher velocities and higher target densities are required for impact fast ignition. The aim of these experiments is shaping the driving pulse to minimize shock heating of the accelerated target and using the focal zoom capability of Nike to achieve higher densities and velocities. Spectroscopic measurements of electron temperature achieved upon impact will complement the neutron time-of-flight ion temperature measurement. Work is supported by US DOE and Office of Naval Research.

Crystalline lens thickness determines the perceived chromatic difference in magnification.

PubMed

Chen, Yun; Schaeffel, Frank

2014-03-01

Since the origin of the high interindividual variability of the chromatic difference in retinal image magnification (CDM) in the human eye is not well understood, optical parameters that might determine its magnitude were studied in 21 healthy subjects with ages ranging from 21 to 58 years. Two psychophysical procedures were used to quantify CDM. They produced highly correlated results. First, a red and a blue square, presented on a black screen, had to be matched in size by the subjects with their right eyes. Second, a filled red and blue square, flickering on top of each other at 2 Hz, had to be adjusted in perceived brightness and then in size to minimize the impression of flicker. CDM varied widely among subjects from 0.0% to 3.6%. Biometric ocular parameters were measured with low coherence interferometry and crystalline lens tilt and decentration with a custom-built Purkinjemeter. Correlations were studied between CDM and corneal power, anterior chamber depth, lens thickness, lens tilt and lens decentration, and vitreous chamber depths. Lens thickness was found significantly correlated with CDM and accounted for 64% of its variance. Vertical lens tilt and decentration were also significantly correlated. It was also found that CDM increased by 3.5% per year, and part of this change can be attributed to the age-related increase in lens thickness.

Bats adjust their mouth gape to zoom their biosonar field of view.

PubMed

Kounitsky, Pavel; Rydell, Jens; Amichai, Eran; Boonman, Arjan; Eitan, Ofri; Weiss, Anthony J; Yovel, Yossi

2015-05-26

Active sensing, where sensory acquisition is actively modulated, is an inherent component of almost all sensory systems. Echolocating bats are a prime example of active sensing. They can rapidly adjust many of their biosonar parameters to optimize sensory acquisition. They dynamically adjust pulse design, pulse duration, and pulse rate within dozens of milliseconds according to the sensory information that is required for the task that they are performing. The least studied and least understood degree of freedom in echolocation is emission beamforming--the ability to change the shape of the sonar sound beam in a functional way. Such an ability could have a great impact on the bat's control over its sensory perception. On the one hand, the bat could direct more energy into a narrow sector to zoom its biosonar field of view, and on the other hand, it could widen the beam to increase the space that it senses. We show that freely behaving bats constantly control their biosonar field of view in natural situations by rapidly adjusting their emitter aperture--the mouth gape. The bats dramatically narrowed the beam when entering a confined space, and they dramatically widened it within dozens of milliseconds when flying toward open space. Hence, mouth-emitting bats dynamically adjust their mouth gape to optimize the area that they sense with their echolocation system.

Bats adjust their mouth gape to zoom their biosonar field of view

PubMed Central

Rydell, Jens; Amichai, Eran; Boonman, Arjan; Eitan, Ofri; Weiss, Anthony J.; Yovel, Yossi

2015-01-01

Active sensing, where sensory acquisition is actively modulated, is an inherent component of almost all sensory systems. Echolocating bats are a prime example of active sensing. They can rapidly adjust many of their biosonar parameters to optimize sensory acquisition. They dynamically adjust pulse design, pulse duration, and pulse rate within dozens of milliseconds according to the sensory information that is required for the task that they are performing. The least studied and least understood degree of freedom in echolocation is emission beamforming—the ability to change the shape of the sonar sound beam in a functional way. Such an ability could have a great impact on the bat’s control over its sensory perception. On the one hand, the bat could direct more energy into a narrow sector to zoom its biosonar field of view, and on the other hand, it could widen the beam to increase the space that it senses. We show that freely behaving bats constantly control their biosonar field of view in natural situations by rapidly adjusting their emitter aperture—the mouth gape. The bats dramatically narrowed the beam when entering a confined space, and they dramatically widened it within dozens of milliseconds when flying toward open space. Hence, mouth-emitting bats dynamically adjust their mouth gape to optimize the area that they sense with their echolocation system. PMID:25941395

Flat-field anastigmatic mirror objective for high-magnification extreme ultraviolet microscopy

NASA Astrophysics Data System (ADS)

Toyoda, Mitsunori

2015-08-01

To apply high-definition microscopy to the extreme ultraviolet (EUV) region in practice, i.e. to enable in situ observation of living tissue and the at-wavelength inspection of lithography masks, we constructed a novel reflective objective made of three multilayer mirrors. This objective is configured as a two-stage imaging system made of a Schwarzschild two-mirror system as the primary objective and an additional magnifier with a single curved mirror. This two-stage configuration can provide a high magnification of 1500, which is suitable for real-time observation with an EUV charge coupled device (CCD) camera. Besides, since off-axis aberrations can be corrected by the magnifier, which provides field flattener optics, we are able to configure the objective as a flat-field anastigmatic system, in which we will have a diffraction-limited spatial resolution over a large field-of-view. This paper describes in detail the optical design of the present objective. After calculating the closed-form equations representing the third-order aberrations of the objective, we apply these equations to practical design examples with a numerical aperture of 0.25 and an operation wavelength of 13.5 nm. We also confirm the imaging performances of this novel design by using the numerical ray-tracing method.

High magnification bronchovideoscopy combined with narrow band imaging could detect capillary loops of angiogenic squamous dysplasia in heavy smokers at high risk for lung cancer.

PubMed

Shibuya, K; Hoshino, H; Chiyo, M; Iyoda, A; Yoshida, S; Sekine, Y; Iizasa, T; Saitoh, Y; Baba, M; Hiroshima, K; Ohwada, H; Fujisawa, T

2003-11-01

We investigated the use of high magnification bronchovideoscopy combined with narrow band imaging (NBI) for the detailed examination of angiogenic squamous dysplasia (ASD). This was carried out in relation to bronchial vascular patterns with abnormal mucosal fluorescence in heavy smokers at high risk for lung cancer. Forty eight patients with sputum cytology specimens suspicious or positive for malignancy were entered into the study. Conventional white light and fluorescence bronchoscopic examination was first performed. Observations by high magnification bronchovideoscopy with conventional white light were made primarily at sites of abnormal fluorescence, and then repeated with NBI light to examine microvascular networks in the bronchial mucosa. Spectral features on the RGB (Red/Green/Blue) sequential videoscope system were changed from the conventional RGB broadband filter to the new NBI filter. The wavelength ranges of the new NBI filter were B1: 400-430 nm, B2: 420-470 nm, and G: 560-590 nm. ASD tissues were also examined using a confocal laser scanning microscope equipped with argon-krypton (488 nm) and argon (514 nm) laser sources. The microvessels, vascular networks of various grades, and dotted vessels in ASD tissues were clearly observed in NBI-B1 images. Diameters of the dotted vessels visible on NBI-B1 images agreed with the diameters of ASD capillary blood vessels diagnosed by pathological examination. Capillary blood vessels were also clearly visualised by green fluorescence by confocal laser scanning microscopy. There was a significant association between the frequency of dotted vessels by NBI-B1 imaging and tissues confirmed as ASD pathologically (p=0.002). High magnification bronchovideoscopy combined with NBI was useful in the detection of capillary blood vessels in ASD lesions at sites of abnormal fluorescence. This may enable the discrimination between ASD and another pre-invasive bronchial lesion.

Shoulder replacement - discharge

MedlinePlus

Total shoulder arthroplasty - discharge; Endoprosthetic shoulder replacement - discharge; Partial shoulder replacement - discharge; Partial shoulder arthroplasty - discharge; Replacement - shoulder - discharge; Arthroplasty - shoulder - ...

SILCC-Zoom: the dynamic and chemical evolution of molecular clouds

NASA Astrophysics Data System (ADS)

Seifried, D.; Walch, S.; Girichidis, P.; Naab, T.; Wünsch, R.; Klessen, R. S.; Glover, S. C. O.; Peters, T.; Clark, P.

2017-12-01

We present 3D 'zoom-in' simulations of the formation of two molecular clouds out of the galactic interstellar medium. We model the clouds - identified from the SILCC simulations - with a resolution of up to 0.06 pc using adaptive mesh refinement in combination with a chemical network to follow heating, cooling and the formation of H2 and CO including (self-) shielding. The two clouds are assembled within a few million years with mass growth rates of up to ∼10-2 M⊙ yr-1 and final masses of ∼50 000 M⊙. A spatial resolution of ≲0.1 pc is required for convergence with respect to the mass, velocity dispersion and chemical abundances of the clouds, although these properties also depend on the cloud definition such as based on density thresholds, H2 or CO mass fraction. To avoid grid artefacts, the progressive increase of resolution has to occur within the free-fall time of the densest structures (1-1.5 Myr) and ≳200 time-steps should be spent on each refinement level before the resolution is progressively increased further. This avoids the formation of spurious, large-scale, rotating clumps from unresolved turbulent flows. While CO is a good tracer for the evolution of dense gas with number densities n ≥ 300 cm-3, H2 is also found for n ≲ 30 cm-3 due to turbulent mixing and becomes dominant at column densities around 30-50 M⊙ pc-2. The CO-to-H2 ratio steadily increases within the first 2 Myr, whereas XCO ≃ 1-4 × 1020 cm-2 (K km s-1)-1 is approximately constant since the CO(1-0) line quickly becomes optically thick.

Use of zooming and pulseshaping for acceleration to high velocities and fusion neutron production on the Nike laser

NASA Astrophysics Data System (ADS)

Karasik, Max; Weaver, J. L.; Aglitskiy, Y.; Kehne, D. M.; Zalesak, S. T.; Velikovich, A. L.; Oh, J.; Obenschain, S. P.; Arikawa, Y.

2011-10-01

We will present results from follow-on experiments to the record-high velocities of 1000 km/s achieved on Nike [Karasik et al, Phys. Plasmas 17, 056317(2010)], in which highly accelerated planar foils of deuterated polystyrene were made to collide with a witness foil to produce ~ 1 Gbar shock pressures and result in heating of matter to thermonuclear temperatures. Still higher velocities and higher target densities are required for impact fast ignition. The aim of these experiments is using the focal zoom capability of Nike and shaping the driving pulse to minimize shock heating of the accelerated target to achieve higher densities and velocities. In-flight target density is inferred from target heating upon collision via DD neutron time-of-flight ion temperature measurement. Work is supported by US DOE (NNSA) and Office of Naval Research. SAIC

Seeing you seeing me: Stereotypes and the stigma magnification effect.

PubMed

Mikolon, Sven; Kreiner, Glen E; Wieseke, Jan

2016-05-01

[Correction Notice: An Erratum for this article was reported in Vol 101(5) of Journal of Applied Psychology (see record 2016-21000-001). In the article, Table 2 contained a production-related formatting error. Values from column 11 onward were shifted upwards in the table. All versions of this article have been corrected.] Despite an increased interest in the phenomenon of stigma in organizations, we know very little about the interactions between those who are stigmatized and those who stigmatize them. Integrating both the perceptions of the stigmatized worker and the stigmatizing customer into one model, the present study addresses this gap. It examines the role of stereotypes held by customers of stigmatized organizations and metastereotypes held by the stigmatized workers themselves (i.e., their shared beliefs of the stereotypes customers associate with them) in frontline exchanges. To do so, data regarding frontline workers (vendors) of homeless-advocate newspapers from 3 different sources (vendors, customers, trained observers) were gathered. Multilevel path-analytic hypotheses tests reveal (a) how frontline workers' prototypicality for a stigmatized organization renders salient a stigma within frontline interactions and (b) how stereotypes by customers and metastereotypes by frontline workers interact with each other in such contacts. The results support a hypothesized interaction between frontline workers' metastereotypes and customers' stereotypes-what we call the "stigma magnification effect". The study also derives important practical implications by linking stigma to frontline workers' discretionary financial gains. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Pinch-force-magnification mechanism of low degree of freedom EMG prosthetic hand for children.

PubMed

Ye, Hesong; Sakoda, Shintaro; Jiang, Yinlai; Morishita, Soichiro; Yokoi, Hiroshi

2015-01-01

EMG prosthetic hands are being extensively studied for the disabled who need them not only for cosmesis but also for the functions to help them with basic daily activities. However, most EMG prosthetic hands are developed for adults. Since the early use of prosthetic hands is important for the children to accept and adapt to them, we are developing low degrees of freedom (DoF) prosthetic hand that is suitable for children. Due to the limited size of a child's hand, the servo motor which drives the MP joint are small-sized and low-power. Hence, a pinch-force-magnification mechanism is required to improve the pinch force of the EMG prosthetic hand. In this paper we designed a wire-driven mechanism which can magnify pinch force by increasing the length of the MP joint's moment arm. Pinch force measurement experiment validated that the pinch force of the prosthetic hand with the mechanism is more than twice of that of the hand with direct drive.

Zooming in on AdS3/CFT2 near a BPS bound

NASA Astrophysics Data System (ADS)

Hartong, Jelle; Lei, Yang; Obers, Niels; Oling, Gerben

2018-05-01

Any ( d + 1)-dimensional CFT with a U(1) flavor symmetry, a BPS bound and an exactly marginal coupling admits a decoupling limit in which one zooms in on the spectrum close to the bound. This limit is an Inönü-Wigner contraction of so(2 , d+1)⊕ u(1) that leads to a relativistic algebra with a scaling generator but no conformal generators. In 2D CFTs, Lorentz boosts are abelian and by adding a second u(1) we find a contraction of two copies of sl(2, ℝ) ⊕ u(1) to two copies of P 2 c , the 2-dimensional centrally extended Poincaré algebra. We show that the bulk is described by a novel non-Lorentzian geometry that we refer to as pseudo-Newton-Cartan geometry. Both the Chern-Simons action on sl(2, ℝ) ⊕ u(1) and the entire phase space of asymptotically AdS3 spacetimes are well-behaved in the corresponding limit if we fix the radial component for the u(1) connection. With this choice, the resulting Newton-Cartan foliation structure is now associated not with time, but with the emerging holographic direction. Since the leaves of this foliation do not mix, the emergence of the holographic direction is much simpler than in AdS3 holography. Furthermore, we show that the asymptotic symmetry algebra of the limit theory consists of a left- and a right-moving warped Virasoro algebra.

Automated exterior inspection of an aircraft with a pan-tilt-zoom camera mounted on a mobile robot

NASA Astrophysics Data System (ADS)

Jovančević, Igor; Larnier, Stanislas; Orteu, Jean-José; Sentenac, Thierry

2015-11-01

This paper deals with an automated preflight aircraft inspection using a pan-tilt-zoom camera mounted on a mobile robot moving autonomously around the aircraft. The general topic is image processing framework for detection and exterior inspection of different types of items, such as closed or unlatched door, mechanical defect on the engine, the integrity of the empennage, or damage caused by impacts or cracks. The detection step allows to focus on the regions of interest and point the camera toward the item to be checked. It is based on the detection of regular shapes, such as rounded corner rectangles, circles, and ellipses. The inspection task relies on clues, such as uniformity of isolated image regions, convexity of segmented shapes, and periodicity of the image intensity signal. The approach is applied to the inspection of four items of Airbus A320: oxygen bay handle, air-inlet vent, static ports, and fan blades. The results are promising and demonstrate the feasibility of an automated exterior inspection.

Application of the high resolution return beam vidicon

NASA Technical Reports Server (NTRS)

Cantella, M. J.

1977-01-01

The Return Beam Vidicon (RBV) is a high-performance electronic image sensor and electrical storage component. It can accept continuous or discrete exposures. Information can be read out with a single scan or with many repetitive scans for either signal processing or display. Resolution capability is 10,000 TV lines/height, and at 100 lp/mm, performance matches or exceeds that of film, particularly with low-contrast imagery. Electronic zoom can be employed effectively for image magnification and data compression. The high performance and flexibility of the RBV permit wide application in systems for reconnaissance, scan conversion, information storage and retrieval, and automatic inspection and test. This paper summarizes the characteristics and performance parameters of the RBV and cites examples of feasible applications.

The shifting zoom: new possibilities for inverse scattering on electrically large domains

NASA Astrophysics Data System (ADS)

Persico, Raffaele; Ludeno, Giovanni; Soldovieri, Francesco; De Coster, Alberic; Lambot, Sebastien

2017-04-01

Inverse scattering is a subject of great interest in diagnostic problems, which are in their turn of interest for many applicative problems as investigation of cultural heritage, characterization of foundations or subservices, identification of unexploded ordnances and so on [1-4]. In particular, GPR data are usually focused by means of migration algorithms, essentially based on a linear approximation of the scattering phenomenon. Migration algorithms are popular because they are computationally efficient and do not require the inversion of a matrix, neither the calculation of the elements of a matrix. In fact, they are essentially based on the adjoint of the linearised scattering operator, which allows in the end to write the inversion formula as a suitably weighted integral of the data [5]. In particular, this makes a migration algorithm more suitable than a linear microwave tomography inversion algorithm for the reconstruction of an electrically large investigation domain. However, this computational challenge can be overcome by making use of investigation domains joined side by side, as proposed e.g. in ref. [3]. This allows to apply a microwave tomography algorithm even to large investigation domains. However, the joining side by side of sequential investigation domains introduces a problem of limited (and asymmetric) maximum view angle with regard to the targets occurring close to the edges between two adjacent domains, or possibly crossing these edges. The shifting zoom is a method that allows to overcome this difficulty by means of overlapped investigation and observation domains [6-7]. It requires more sequential inversion with respect to adjacent investigation domains, but the really required extra-time is minimal because the matrix to be inverted is calculated ones and for all, as well as its singular value decomposition: what is repeated more time is only a fast matrix-vector multiplication. References [1] M. Pieraccini, L. Noferini, D. Mecatti, C

High Resolution PET with 250 micrometer LSO Detectors and Adaptive Zoom

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

Cherry, Simon R.; Qi, Jinyi

2012-01-08

There have been impressive improvements in the performance of small-animal positron emission tomography (PET) systems since their first development in the mid 1990s, both in terms of spatial resolution and sensitivity, which have directly contributed to the increasing adoption of this technology for a wide range of biomedical applications. Nonetheless, current systems still are largely dominated by the size of the scintillator elements used in the detector. Our research predicts that developing scintillator arrays with an element size of 250 {micro}m or smaller will lead to an image resolution of 500 {micro}m when using 18F- or 64Cu-labeled radiotracers, giving amore » factor of 4-8 improvement in volumetric resolution over the highest resolution research systems currently in existence. This proposal had two main objectives: (i) To develop and evaluate much higher resolution and efficiency scintillator arrays that can be used in the future as the basis for detectors in a small-animal PET scanner where the spatial resolution is dominated by decay and interaction physics rather than detector size. (ii) To optimize one such high resolution, high sensitivity detector and adaptively integrate it into the existing microPET II small animal PET scanner as a 'zoom-in' detector that provides higher spatial resolution and sensitivity in a limited region close to the detector face. The knowledge gained from this project will provide valuable information for building future PET systems with a complete ring of very high-resolution detector arrays and also lay the foundations for utilizing high-resolution detectors in combination with existing PET systems for localized high-resolution imaging.« less

Atomic force microscopy and scanning electron microscopy evaluation of efficacy of scaling and root planing using magnification: A randomized controlled clinical study

PubMed Central

Mohan, Ranjana; Agrawal, Sudhanshu; Gundappa, Mohan

2013-01-01

Aim: A randomized controlled clinical study was undertaken to evaluate the effectiveness of scaling and root planing (SRP) by using Magnifying Loupes (ML) and dental operating microscope (DOM). Materials and Methods: A total of 90 human teeth scheduled for extraction from 18 patients aged between 25 and 65 years suffering from generalized chronic severe periodontitis were randomly assigned to three treatment groups. Group 1 consisted SRP performed without using magnification (unaided), Group 2-SRP with ML and Group 3-SRP with DOM. Following extractions, samples were prepared for (i) evaluation of surface topography by atomic force microscopy, (ii) presence of smear layer, debris by scanning electron microscopy (iii) elemental analysis by energy dispersive X-ray analysis. Data was subjected to statistical analysis using analysis of variance, post-hoc (Tukey-HSD) and Chi-square test. Results: Statistically significant (P < 0.001) difference was found among the different treatment groups. Group 3 was the best while Group 1 was the least effective technique for SRP. Order of efficacy in terms of the surface was found to be - Palatal < Lingual < Distal ≃ Mesial < Buccal. Efficiency in mandibular to maxillary teeth was found to be significant (P < 0.05), also anterior to posterior teeth (P < 0.05). Conclusion: Magnification tools significantly enhance the efficacy of supragingival and subgingival SRP. PMID:24124292

The role of low-level magnification in visual inspection with acetic acid for the early detection of cervical neoplasia.

PubMed

Sankaranarayanan, Rengaswamy; Shastri, Surendra S; Basu, Parthasarathi; Mahé, Cédric; Mandal, Ranajit; Amin, Geethanjali; Roy, Chinmayi; Muwonge, Richard; Goswami, Smriti; Das, Pradip; Chinoy, Roshini; Frappart, Lucien; Patil, Sharmila; Choudhury, Devjani; Mukherjee, Titha; Dinshaw, Ketayun

2004-01-01

Several studies have investigated the accuracy of naked eye visual inspection with acetic acid (VIA) in the early detection of cervical neoplasia. It is not clear whether low-level (2-4x) magnification (VIAM) can improve the sensitivity and specificity of VIA. The accuracy of both VIA and VIAM, provided by independent health workers, were evaluated in three cross-sectional studies involving 18,675 women aged 25-65 years in Kolkata and Mumbai in India. All screened women were investigated with colposcopy and biopsies were obtained based on colposcopy findings. The final disease status was based on the reference standard of histology (if biopsies had been taken) or colposcopy. Data from the studies were pooled to calculate the test characteristics for the detection of high-grade squamous intraepithelial lesions (HSIL). 14.1% and 14.2% were positive on testing with VIA and VIAM respectively. Two hundred twenty-nine were diagnosed with HSIL and 68 with invasive cancer. The pooled sensitivity, specificity, positive and negative predictive values for VIA in detecting high-grade squamous intraepithelial lesions (HSIL) were 60.3% (95% CI: 53.6-66.7), 86.8% (95% CI: 86.3-87.3), 5.9% (95% CI: 5.0-7.0), and 99.4% (95% CI: 99.2-99.5), respectively. The values were 64.2% (95% CI: 57.6-70.4), 86.8% (95% CI: 86.2-87.3), 6.3% (95% CI: 5.3-7.3) and 99.4% (95% CI: 99.3-99.6), respectively, for VIAM. Low-level magnification did not improve the test performance of naked eye visualization of acetic acid impregnated uterine cervix.

Assessment of fresh breast tissue specimens with confocal strip-mosaicking microscopy in an emulated pathology setting (Conference Presentation)

NASA Astrophysics Data System (ADS)

Abeytunge, Sanjeewa; Larson, Bjorg A.; Peterson, Gary; Rajadhyaksha, Milind; Murray, Melissa

2017-02-01

Confocal microscopy is in clinical use to diagnose skin cancers in the United States and in Europe. Potentially, this technology may provide bed-side pathology in breast cancer surgery during tumor removal. Initial studies have described major findings of invasive breast cancers as seen on fluorescence confocal microscopy. In many of these studies the region of interest (ROI) used in the analysis was user-selected and small (typically 15 square-mm). Although these important findings open exploration into rapid pathology, further development and implementation in a surgical setting will require examination of large specimens in a blinded fashion that will address the needs of typical surgical settings. In post surgery pathology viewing, pathologists inspect the entire pathology section with a low (2X) magnification objective lens initially and then zoomed in to ROIs with higher magnification lenses (10X to 40X) magnifications to further investigate suspected regions. In this study we explore the possibility of implementation in a typical surgical setting with a new microscope, termed confocal strip-mosaicking microscope (CSM microscope), which images an area of 400 square-mm (2 cm x 2 cm) of tissue with cellular level resolution in 10 minutes. CSM images of 34 human breast tissue specimens from 18 patients were blindly analyzed by a board-certified pathologist and correlated with the corresponding standard fixed histopathology. Invasive tumors and benign tissue were clearly identified in CSM images. Thirty specimens were concordant for images-to-histopathology correlation while four were discordant. Preliminary results from on-going work to molecularly target tumor margin will also be presented.

Optical method for high magnification imaging and video recording of live cells at sub-micron resolution

NASA Astrophysics Data System (ADS)

Romo, Jaime E., Jr.

Optical microscopy, the most common technique for viewing living microorganisms, is limited in resolution by Abbe's criterion. Recent microscopy techniques focus on circumnavigating the light diffraction limit by using different methods to obtain the topography of the sample. Systems like the AFM and SEM provide images with fields of view in the nanometer range with high resolvable detail, however these techniques are expensive, and limited in their ability to document live cells. The Dino-Lite digital microscope coupled with the Zeiss Axiovert 25 CFL microscope delivers a cost-effective method for recording live cells. Fields of view ranging from 8 microns to 300 microns with fair resolution provide a reliable method for discovering native cell structures at the nanoscale. In this report, cultured HeLa cells are recorded using different optical configurations resulting in documentation of cell dynamics at high magnification and resolution.

Development of the local magnification method for quantitative evaluation of endoscope geometric distortion

NASA Astrophysics Data System (ADS)

Wang, Quanzeng; Cheng, Wei-Chung; Suresh, Nitin; Hua, Hong

2016-05-01

With improved diagnostic capabilities and complex optical designs, endoscopic technologies are advancing. As one of the several important optical performance characteristics, geometric distortion can negatively affect size estimation and feature identification related diagnosis. Therefore, a quantitative and simple distortion evaluation method is imperative for both the endoscopic industry and the medical device regulatory agent. However, no such method is available yet. While the image correction techniques are rather mature, they heavily depend on computational power to process multidimensional image data based on complex mathematical model, i.e., difficult to understand. Some commonly used distortion evaluation methods, such as the picture height distortion (DPH) or radial distortion (DRAD), are either too simple to accurately describe the distortion or subject to the error of deriving a reference image. We developed the basic local magnification (ML) method to evaluate endoscope distortion. Based on the method, we also developed ways to calculate DPH and DRAD. The method overcomes the aforementioned limitations, has clear physical meaning in the whole field of view, and can facilitate lesion size estimation during diagnosis. Most importantly, the method can facilitate endoscopic technology to market and potentially be adopted in an international endoscope standard.

A micro-optical system for endoscopy based on mechanical compensation paradigm using miniature piezo-actuation.

PubMed

Cerveri, Pietro; Zazzarini, Cynthia Corinna; Patete, Paolo; Baroni, Guido

2014-06-01

The goal of the study was to investigate the feasibility of a novel miniaturized optical system for endoscopy. Fostering the mechanical compensation paradigm, the modeled optical system, composed by 14 lenses, separated in 4 different sets, had a total length of 15.55mm, an effective focal length ranging from 1.5 to 4.5mm with a zoom factor of about 2.8×, and an angular field of view up to 56°. Predicted maximum lens travel was less than 3.5mm. The consistency of the image plane height across the magnification range testified the zoom capability. The maximum predicted achromatic astigmatism, transverse spherical aberration, longitudinal spherical aberration and relative distortion were less than or equal to 25μm, 15μm, 35μm and 12%, respectively. Tests on tolerances showed that the manufacturing and opto-mechanics mounting are critical as little deviations from design dramatically decrease the optical performances. However, recent micro-fabrication technology can guarantee tolerances close to nominal design. A closed-loop actuation unit, devoted to move the zoom and the focus lens sets, was implemented adopting miniaturized squiggle piezo-motors and magnetic position encoders based on Hall effect. Performance results, using a prototypical test board, showed a positioning accuracy of less than 5μm along a lens travel path of 4.0mm, which was in agreement with the lens set motion features predicted by the analysis. In conclusion, this study demonstrated the feasibility of the optical design and the viability of the actuation approach while tolerances must be carefully taken into account. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

Zooming in on star formation in the brightest galaxies of the early Universe discovered with the Planck and Herschel satellites

NASA Astrophysics Data System (ADS)

Canameras, Raoul

2016-09-01

Strongly gravitationally lensed galaxies offer an outstanding opportunity to characterize the most intensely star-forming galaxies in the high-redshift universe. In the most extreme cases, one can probe the mechanisms that underlie the intense star formation on the scales of individual star-forming regions. This requires very fortuitous gravitational lensing configurations offering magnification factors >>10, which are particularly rare toward the high-redshift dusty star-forming galaxies. The Planck's Dusty GEMS (Gravitationally Enhanced subMillimeter Sources) sample contains eleven of the brightest high-redshift galaxies discovered with the Planck submillimeter all-sky survey, with flux densities between 300 and 1000 mJy at 350 microns, factors of a few brighter than the majority of lensed sources previously discovered with other surveys. Six of them are above the 90% completeness limit of the Planck Catalog of Compact Sources (PCCS), suggesting that they are among the brightest high-redshift sources on the sky selected by their active star formation. This thesis comes within the framework of the extensive multi-wavelength follow-up programme designed to determine the overall properties of the high-redshift sources and to probe the lensing configurations. Firstly, to characterize the intervening lensing structures and calculate lensing models, I use optical and near/mid-infrared imaging and spectroscopy. I deduce that our eleven GEMS are aligned with intervening matter overdensities at intermediate redshift, either massive isolated galaxies or galaxy groups and clusters. The foreground sources exhibit evolved stellar populations of a few giga years, characteristic of early-type galaxies. Moreover, the first detailed models of the light deflection toward the GEMS suggest magnification factors systematically >10, and >20 for some lines-of-sight. Secondly, we observe the GEMS in the far-infrared and sub-millimeter domains in order to characterize the background

Persistent and automatic intraoperative 3D digitization of surfaces under dynamic magnifications of an operating microscope

PubMed Central

Kumar, Ankur N.; Miga, Michael I.; Pheiffer, Thomas S.; Chambless, Lola B.; Thompson, Reid C.; Dawant, Benoit M.

2014-01-01

One of the major challenges impeding advancement in image-guided surgical (IGS) systems is the soft-tissue deformation during surgical procedures. These deformations reduce the utility of the patient’s preoperative images and may produce inaccuracies in the application of preoperative surgical plans. Solutions to compensate for the tissue deformations include the acquisition of intraoperative tomographic images of the whole organ for direct displacement measurement and techniques that combines intraoperative organ surface measurements with computational biomechanical models to predict subsurface displacements. The later solution has the advantage of being less expensive and amenable to surgical workflow. Several modalities such as textured laser scanners, conoscopic holography, and stereo-pair cameras have been proposed for the intraoperative 3D estimation of organ surfaces to drive patient-specific biomechanical models for the intraoperative update of preoperative images. Though each modality has its respective advantages and disadvantages, stereo-pair camera approaches used within a standard operating microscope is the focus of this article. A new method that permits the automatic and near real-time estimation of 3D surfaces (at 1Hz) under varying magnifications of the operating microscope is proposed. This method has been evaluated on a CAD phantom object and on full-length neurosurgery video sequences (~1 hour) acquired intraoperatively by the proposed stereovision system. To the best of our knowledge, this type of validation study on full-length brain tumor surgery videos has not been done before. The method for estimating the unknown magnification factor of the operating microscope achieves accuracy within 0.02 of the theoretical value on a CAD phantom and within 0.06 on 4 clinical videos of the entire brain tumor surgery. When compared to a laser range scanner, the proposed method for reconstructing 3D surfaces intraoperatively achieves root mean square

Persistent and automatic intraoperative 3D digitization of surfaces under dynamic magnifications of an operating microscope.

PubMed

Kumar, Ankur N; Miga, Michael I; Pheiffer, Thomas S; Chambless, Lola B; Thompson, Reid C; Dawant, Benoit M

2015-01-01

One of the major challenges impeding advancement in image-guided surgical (IGS) systems is the soft-tissue deformation during surgical procedures. These deformations reduce the utility of the patient's preoperative images and may produce inaccuracies in the application of preoperative surgical plans. Solutions to compensate for the tissue deformations include the acquisition of intraoperative tomographic images of the whole organ for direct displacement measurement and techniques that combines intraoperative organ surface measurements with computational biomechanical models to predict subsurface displacements. The later solution has the advantage of being less expensive and amenable to surgical workflow. Several modalities such as textured laser scanners, conoscopic holography, and stereo-pair cameras have been proposed for the intraoperative 3D estimation of organ surfaces to drive patient-specific biomechanical models for the intraoperative update of preoperative images. Though each modality has its respective advantages and disadvantages, stereo-pair camera approaches used within a standard operating microscope is the focus of this article. A new method that permits the automatic and near real-time estimation of 3D surfaces (at 1 Hz) under varying magnifications of the operating microscope is proposed. This method has been evaluated on a CAD phantom object and on full-length neurosurgery video sequences (∼1 h) acquired intraoperatively by the proposed stereovision system. To the best of our knowledge, this type of validation study on full-length brain tumor surgery videos has not been done before. The method for estimating the unknown magnification factor of the operating microscope achieves accuracy within 0.02 of the theoretical value on a CAD phantom and within 0.06 on 4 clinical videos of the entire brain tumor surgery. When compared to a laser range scanner, the proposed method for reconstructing 3D surfaces intraoperatively achieves root mean square

Esophageal replacement.

PubMed

Kunisaki, Shaun M; Coran, Arnold G

2017-04-01

This article focuses on esophageal replacement as a surgical option for pediatric patients with end-stage esophageal disease. While it is obvious that the patient׳s own esophagus is the best esophagus, persisting with attempts to retain a native esophagus with no function and at all costs are futile and usually detrimental to the overall well-being of the child. In such cases, the esophagus should be abandoned, and the appropriate esophageal replacement is chosen for definitive reconstruction. We review the various types of conduits used for esophageal replacement and discuss the unique advantages and disadvantages that are relevant for clinical decision-making. Copyright © 2017 Elsevier Inc. All rights reserved.

Variable diameter CO₂ laser ring-cutting system adapted to a zoom microscope for applications on polymer tapes.

PubMed

Förster, Erik; Bohnert, Patrick; Kraus, Matthias; Kilper, Roland; Müller, Ute; Buchmann, Martin; Brunner, Robert

2016-11-20

This paper presents the conception and implementation of a variable diameter ring-cutting system for a CO₂ laser with a working wavelength of 10.6 μm. The laser-cutting system is adapted to an observation zoom microscope for combined use and is applicable for the extraction of small circular areas from polymer films, such as forensic adhesive tapes in a single shot. As an important characteristic for our application, the variable diameter ring-cutting system provides telecentricity in the target area. Ring diameters are continuously tunable between 500 μm and 2 mm. A minimum width of less than 20 μm was found for the ring profile edge. The basic characteristics of the system, including telecentricity, were experimentally evaluated and demonstrated by cutting experiments on different polymer tapes and further exemplary samples.

Simulations and experiments on vibration damping for zoom-holography and nano-scanning at the GINIX

NASA Astrophysics Data System (ADS)

Osterhoff, Markus; Luley, Peter; Sprung, Michael; Salditt, Tim

2017-09-01

The Göttingen Instrument for Nano-Imaging with X-ray (GINIX) is a holography endstation located at the P10 coherence beamline at PETRA III, designed and operated by the University of Göttingen in close collaboration with DESY Photon science Hamburg [1-2]. GINIX is designed as a waveguide based holography experiment with a Kirkpatrick-Baez nanofocus. Its versatility has stimulated a great manifold of imaging modalities. Today, users choose the GINIX setup not only for its few nm coherent waveguide beams (e.g. for ptychography or holography), but also to carry out scanning SAXS measurements to probe local anisotropies with sub-micron real-space and even higher reciprocal space resolution. In addition, it is possible to combine different detectors for e.g. simultaneous SAXS/WAXS and fluorescence measurements [3]. We summarise our ongoing efforts to reduce vibrations in the setup, and present latest experimental results obtained with GINIX, focusing on the unique capabilities offered by its versatile and flexible design. The overview includes results from different imaging schemes such as waveguide based zoom-tomography and user examples in WAXS geometry. We show how to correlate complementary techniques like holography and scanning SAXS and present first results obtained using a new fast sample scanner for Multilayer Zone Plate imaging..

Trophic Magnification of Parabens and Their Metabolites in a Subtropical Marine Food Web.

PubMed

Xue, Xiaohong; Xue, Jingchuan; Liu, Wenbin; Adams, Douglas H; Kannan, Kurunthachalam

2017-01-17

Despite the widespread use of parabens in a range of consumer products, little is known about bioaccumulation of these chemicals in aquatic environments. In this study, six parabens and four of their common metabolites were measured in abiotic (water, sediment) and biotic (fish including sharks, invertebrates, plants) samples collected from a subtropical marine food web in coastal Florida. Methyl paraben (MeP) was found in all abiotic (100%) and a majority of biotic (87%) samples. 4-Hydroxy benzoic acid (4-HB) was the most abundant metabolite, found in 97% of biotic and all abiotic samples analyzed. The food chain accumulation of MeP and 4-HB was investigated for this food web. The trophic magnification factor (TMF) of MeP was estimated to be 1.83, which suggests considerable bioaccumulation and biomagnification of this compound in the marine food web. In contrast, a low TMF value was found for 4-HB (0.30), indicating that this compound is metabolized and excreted along the food web. This is the first study to document the widespread occurrence of parabens and their metabolites in fish, invertebrates, seagrasses, marine macroalgae, mangroves, seawater, and ocean sediments and to elucidate biomagnification potential of MeP in a marine food web.

Application and System Design of Elastomer Based Optofluidic Lenses

NASA Astrophysics Data System (ADS)

Savidis, Nickolaos

Adaptive optic technology has revolutionized real time correction of wavefront aberrations. Optofluidic based applied optic devices have offered an opportunity to produce flexible refractive lenses in the correction of wavefronts. Fluidic lenses have superiority relative to their solid lens counterparts in their capabilities of producing tunable optical systems, that when synchronized, can produce real time variable systems with no moving parts. We have developed optofluidic fluidic lenses for applications of applied optical devices, as well as ophthalmic optic devices. The first half of this dissertation discusses the production of fluidic lenses as optical devices. In addition, the design and testing of various fluidic systems made with these components are evaluated. We begin with the creation of spherical or defocus singlet fluidic lenses. We then produced zoom optical systems with no moving parts by synchronizing combinations of these fluidic spherical lenses. The variable power zoom system incorporates two singlet fluidic lenses that are synchronized. The coupled device has no moving parts and has produced a magnification range of 0.1 x to 10 x or a 20 x magnification range. The chapter after fluidic zoom technology focuses on producing achromatic lens designs. We offer an analysis of a hybrid diffractive and refractive achromat that offers discrete achromatized variable focal lengths. In addition, we offer a design of a fully optofluidic based achromatic lens. By synchronizing the two membrane surfaces of the fluidic achromat we develop a design for a fluidic achromatic lens. The second half of this dissertation discusses the production of optofluidic technology in ophthalmic applications. We begin with an introduction to an optofluidic phoropter system. A fluidic phoropter is designed through the combination of a defocus lens with two cylindrical fluidic lenses that are orientated 45° relative to each other. Here we discuss the designs of the fluidic

Large-Scale Overlays and Trends: Visually Mining, Panning and Zooming the Observable Universe.

PubMed

Luciani, Timothy Basil; Cherinka, Brian; Oliphant, Daniel; Myers, Sean; Wood-Vasey, W Michael; Labrinidis, Alexandros; Marai, G Elisabeta

2014-07-01

We introduce a web-based computing infrastructure to assist the visual integration, mining and interactive navigation of large-scale astronomy observations. Following an analysis of the application domain, we design a client-server architecture to fetch distributed image data and to partition local data into a spatial index structure that allows prefix-matching of spatial objects. In conjunction with hardware-accelerated pixel-based overlays and an online cross-registration pipeline, this approach allows the fetching, displaying, panning and zooming of gigabit panoramas of the sky in real time. To further facilitate the integration and mining of spatial and non-spatial data, we introduce interactive trend images-compact visual representations for identifying outlier objects and for studying trends within large collections of spatial objects of a given class. In a demonstration, images from three sky surveys (SDSS, FIRST and simulated LSST results) are cross-registered and integrated as overlays, allowing cross-spectrum analysis of astronomy observations. Trend images are interactively generated from catalog data and used to visually mine astronomy observations of similar type. The front-end of the infrastructure uses the web technologies WebGL and HTML5 to enable cross-platform, web-based functionality. Our approach attains interactive rendering framerates; its power and flexibility enables it to serve the needs of the astronomy community. Evaluation on three case studies, as well as feedback from domain experts emphasize the benefits of this visual approach to the observational astronomy field; and its potential benefits to large scale geospatial visualization in general.

High frequency mode shapes characterisation using Digital Image Correlation and phase-based motion magnification

NASA Astrophysics Data System (ADS)

Molina-Viedma, A. J.; Felipe-Sesé, L.; López-Alba, E.; Díaz, F.

2018-03-01

High speed video cameras provide valuable information in dynamic events. Mechanical characterisation has been improved by the interpretation of the behaviour in slow-motion visualisations. In modal analysis, videos contribute to the evaluation of mode shapes but, generally, the motion is too subtle to be interpreted. In latest years, image treatment algorithms have been developed to generate a magnified version of the motion that could be interpreted by naked eye. Nevertheless, optical techniques such as Digital Image Correlation (DIC) are able to provide quantitative information of the motion with higher sensitivity than naked eye. For vibration analysis, mode shapes characterisation is one of the most interesting DIC performances. Full-field measurements provide higher spatial density than classical instrumentations or Scanning Laser Doppler Vibrometry. However, the accurateness of DIC is reduced at high frequencies as a consequence of the low displacements and hence it is habitually employed in low frequency spectra. In the current work, the combination of DIC and motion magnification is explored in order to provide numerical information in magnified videos and perform DIC mode shapes characterisation at unprecedented high frequencies through increasing the amplitude of displacements.

Using Eulerian video magnification to enhance detection of fasciculations in people with amyotrophic lateral sclerosis.

PubMed

Van Hillegondsberg, Ludo; Carr, Jonathan; Brey, Naeem; Henning, Franclo

2017-12-01

This study seeks to determine whether the use of Eulerian video magnification (EVM) increases the detection of muscle fasciculations in people with amyotrophic lateral sclerosis (PALS) compared with direct clinical observation (DCO). Thirty-second-long video recordings were taken of 9 body regions of 7 PALS and 7 controls, and fasciculations were counted by DCO during the same 30-s period. The video recordings were then motion magnified and reviewed by 2 independent assessors. In PALS, median fasciculation count per body region was 1 by DCO (range 0-10) and 3 in the EVM recordings (range 0-15; P < 0.0001). EVM revealed more fasciculations than DCO in 61% of recordings. In controls, median fasciculation count was 0 for both DCO and EVM. Compared with DCO, EVM significantly increased the detection of fasciculations in body regions of PALS. When it is used to supplement clinical examination, EVM has the potential to facilitate the diagnosis of ALS. Muscle Nerve 56: 1063-1067, 2017. © 2017 Wiley Periodicals, Inc.

Constraints on Planetary Companions in the Magnification A=256 Microlensing Event OGLE-2003-BLG-423

NASA Astrophysics Data System (ADS)

Yoo, Jaiyul; DePoy, D. L.; Gal-Yam, A.; Gaudi, B. S.; Gould, A.; Han, C.; Lipkin, Y.; Maoz, D.; Ofek, E. O.; Park, B.-G.; Pogge, R. W.; Mu Fun Collaboration; Szymański, M. K.; Udalski, A.; Szewczyk, O.; Kubiak, M.; Żebruń, K.; Pietrzyński, G.; Soszyński, I.; Wyrzykowski, Ł.; OGLE Collaboration

2004-12-01

We develop a new method of modeling microlensing events based on a Monte Carlo simulation that incorporates both a Galactic model and the constraints imposed by the observed characteristics of the event. The method provides an unbiased way to analyze the event, especially when parameters are poorly constrained by the observed light curve. We apply this method to search for planetary companions of the lens in OGLE-2003-BLG-423, whose maximum magnification Amax=256+/-43 (or Amax=400+/-115 from the light-curve data alone) is the highest among single-lens events ever recorded. The method permits us for the first time to place constraints directly in the planet mass-projected physical separation plane rather than in the mass ratio-Einstein radius plane as was done previously. For example, Jovian-mass companions of main-sequence stars at 2.5 AU are excluded with 80% efficiency. Based in part on observations obtained with the 1.3 m Warsaw Telescope at the Las Campanas Observatory of the Carnegie Institution of Washington.

Hip Replacement Surgery

MedlinePlus

... Download Download EPUB Download PDF What is it? Points To Remember About Hip Replacement Surgery Hip replacement ... This leaves your hands and arms free for balance or to use crutches. Use a long-handled " ...

The test about blood serum capabilities in maintaining the quality of bull spermatozoa during storage in cep diluent at refrigerator temperature

NASA Astrophysics Data System (ADS)

Ducha, Nur

2018-03-01

The storage of spermatozoa requires a protective material from cold shock events and the presence of free radicals.In CEP diluent contain BSA, that was used as spermatozoa protection. This study aim was to examine the ability of cow blood serum in replacing BSA as spermatozoa protective in CEP diluent. Fresh semen from Limousin bull was diluted with CEP diluent + BSA as control, in the treatment group were CEP without BSA, but replaced with 3%, 5%, and 7% serum from fresh blood. Spermatozoa quality tests included motility and viability. The motility of spermatozoa was observed by two people using a light microscope with 200 X magnification at temperature of 37°C. The method of viability observation was eosin nigrosin staining, and observed under a light microscope with 400 X magnification. The results showed that the replacement of cow blood serum with various concentrations gave different effects on the quality of spermatozoa. The best motility and viability of the treatment group was at serum concentrations of 5% after eight days storage and was not significantly different from the controls. The conclusion in this study was cow blood serum can replace BSA in CEP diluents.

Implementing Replacement Cost Accounting

DTIC Science & Technology

1976-12-01

cost accounting Clickener, John Ross Monterey, California. Naval Postgraduate School http://hdl.handle.net/10945/17810 Downloaded from NPS Archive...Calhoun IMPLEMENTING REPLACEMENT COST ACCOUNTING John Ross CHckener NAVAL POSTGRADUATE SCHOOL Monterey, California THESIS IMPLEMENTING REPLACEMENT COST ...Implementing Replacement Cost Accounting 7. AUTHORS John Ross Clickener READ INSTRUCTIONS BEFORE COMPLETING FORM 3. RECIPIENT’S CATALOG NUMBER 9. TYRE OF

X-ray tests of a two-dimensional stigmatic imaging scheme with variable magnifications

DOE PAGES

Lu, J.; Bitter, M.; Hill, K. W.; ...

2014-07-22

A two-dimensional stigmatic x-ray imaging scheme, consisting of two spherically bent crystals, one concave and one convex, was recently proposed [M. Bitter et al., Rev. Sci. Instrum. 83, 10E527 (2012)]. We report that the Bragg angles and the radii of curvature of the two crystals of this imaging scheme are matched to eliminate the astigmatism and to satisfy the Bragg condition across both crystal surfaces for a given x-ray energy. In this paper, we consider more general configurations of this imaging scheme, which allow us to vary the magnification for a given pair of crystals and x-ray energy. The stigmaticmore » imaging scheme has been validated for the first time by imaging x-rays generated by a micro-focus x-ray source with source size of 8.4 μm validated by knife-edge measurements. Results are presented from imaging the tungsten Lα1 emission at 8.3976 keV, using a convex Si-422 crystal and a concave Si-533 crystal with 2d-spacings of 2.21707 Å and 1.65635 Å and radii of curvature of 500 ± 1 mm and 823 ± 1 mm, respectively, showing a spatial resolution of 54.9 μm. Finally, this imaging scheme is expected to be of interest for the two-dimensional imaging of laser produced plasmas.« less

Dual-focus versus conventional magnification endoscopy for the diagnosis of superficial squamous neoplasms in the pharynx and esophagus: a randomized trial.

PubMed

Goda, Kenichi; Dobashi, Akira; Yoshimura, Noboru; Aihara, Hiroyuki; Kato, Masayuki; Sumiyama, Kazuki; Toyoizumi, Hirobumi; Kato, Tomohiro; Saijo, Hiroki; Ikegami, Masahiro; Tajiri, Hisao

2016-04-01

Conventional magnification narrow-band imaging (CM-NBI) endoscopy has demonstrated high diagnostic accuracy for superficial squamous neoplasms in the pharynx and esophagus. This study aimed to evaluate the diagnostic utility of the newly developed dual-focus NBI (DF-NBI) compared with that of CM-NBI. We recruited patients with squamous cell carcinoma (SCC) in the head and neck, or esophagus, or with a history of SCC. The primary endpoint of this prospective controlled non-inferiority trial was the sensitivity of DF-NBI and CM-NBI for detecting superficial carcinoma in the pharynx and esophagus. Secondary endpoints included other diagnostic values and the resolving power of each endoscope. Superficial carcinoma was defined as high grade dysplasia and SCC invading up to the submucosal layer. The study included 93 patients. A total of 28 superficial carcinomas were detected in the pharynx and esophagus. The sensitivities of DF-NBI and CM-NBI for superficial carcinoma were 82 % and 71 %, respectively. The lower limit of the 90 % confidence interval for the difference between the sensitivities exceeded the non-inferiority threshold. The specificity and overall accuracy of DF-NBI vs. CM-NBI were 93 % vs. 90 % and 91 % vs. 86 %, respectively (both non-significant differences). The maximum resolving power of a conventional magnification endoscope was significantly higher than a dual-focus endoscope (7.2 µm vs. 11.6 µm: P < 0.001). The findings indicate the non-inferiority of DF-NBI versus CM-NBI in detecting superficial carcinoma in the pharynx and esophagus. DF-NBI appears to have a resolving power that, although significantly lower, is sufficient to achieve high diagnostic accuracy, comparable to that of CM-NBI.University Hospital Medical Information Network (UMIN, No. 000007585). © Georg Thieme Verlag KG Stuttgart · New York.

Effect of contrast enhancement prior to iteration procedure on image correction for soft x-ray projection microscopy

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

Jamsranjav, Erdenetogtokh, E-mail: ja.erdenetogtokh@gmail.com; Shiina, Tatsuo, E-mail: shiina@faculity.chiba-u.jp; Kuge, Kenichi

2016-01-28

Soft X-ray microscopy is well recognized as a powerful tool of high-resolution imaging for hydrated biological specimens. Projection type of it has characteristics of easy zooming function, simple optical layout and so on. However the image is blurred by the diffraction of X-rays, leading the spatial resolution to be worse. In this study, the blurred images have been corrected by an iteration procedure, i.e., Fresnel and inverse Fresnel transformations repeated. This method was confirmed by earlier studies to be effective. Nevertheless it was not enough to some images showing too low contrast, especially at high magnification. In the present study,more » we tried a contrast enhancement method to make the diffraction fringes clearer prior to the iteration procedure. The method was effective to improve the images which were not successful by iteration procedure only.« less

Improved image quality in pinhole SPECT by accurate modeling of the point spread function in low magnification systems

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

Pino, Francisco; Roé, Nuria; Aguiar, Pablo, E-mail: pablo.aguiar.fernandez@sergas.es

2015-02-15

Purpose: Single photon emission computed tomography (SPECT) has become an important noninvasive imaging technique in small-animal research. Due to the high resolution required in small-animal SPECT systems, the spatially variant system response needs to be included in the reconstruction algorithm. Accurate modeling of the system response should result in a major improvement in the quality of reconstructed images. The aim of this study was to quantitatively assess the impact that an accurate modeling of spatially variant collimator/detector response has on image-quality parameters, using a low magnification SPECT system equipped with a pinhole collimator and a small gamma camera. Methods: Threemore » methods were used to model the point spread function (PSF). For the first, only the geometrical pinhole aperture was included in the PSF. For the second, the septal penetration through the pinhole collimator was added. In the third method, the measured intrinsic detector response was incorporated. Tomographic spatial resolution was evaluated and contrast, recovery coefficients, contrast-to-noise ratio, and noise were quantified using a custom-built NEMA NU 4–2008 image-quality phantom. Results: A high correlation was found between the experimental data corresponding to intrinsic detector response and the fitted values obtained by means of an asymmetric Gaussian distribution. For all PSF models, resolution improved as the distance from the point source to the center of the field of view increased and when the acquisition radius diminished. An improvement of resolution was observed after a minimum of five iterations when the PSF modeling included more corrections. Contrast, recovery coefficients, and contrast-to-noise ratio were better for the same level of noise in the image when more accurate models were included. Ring-type artifacts were observed when the number of iterations exceeded 12. Conclusions: Accurate modeling of the PSF improves resolution, contrast, and

Magnifying Smartphone Screen Using Google Glass for Low-Vision Users.

PubMed

Pundlik, Shrinivas; HuaQi Yi; Rui Liu; Peli, Eli; Gang Luo

2017-01-01

Magnification is a key accessibility feature used by low-vision smartphone users. However, small screen size can lead to loss of context and make interaction with magnified displays challenging. We hypothesize that controlling the viewport with head motion can be natural and help in gaining access to magnified displays. We implement this idea using a Google Glass that displays the magnified smartphone screenshots received in real time via Bluetooth. Instead of navigating with touch gestures on the magnified smartphone display, the users can view different screen locations by rotating their head, and remotely interacting with the smartphone. It is equivalent to looking at a large virtual image through a head contingent viewing port, in this case, the Glass display with ~ 15 ° field of view. The system can transfer seven screenshots per second at 8 × magnification, sufficient for tasks where the display content does not change rapidly. A pilot evaluation of this approach was conducted with eight normally sighted and four visually impaired subjects performing assigned tasks using calculator and music player apps. Results showed that performance in the calculation task was faster with the Glass than with the phone's built-in screen zoom. We conclude that head contingent scanning control can be beneficial in navigating magnified small smartphone displays, at least for tasks involving familiar content layout.

Influence of Total Knee Arthroplasty on Gait Mechanics of the Replaced and Non-Replaced Limb During Stair Negotiation.

PubMed

Standifird, Tyler W; Saxton, Arnold M; Coe, Dawn P; Cates, Harold E; Reinbolt, Jeffrey A; Zhang, Songning

2016-01-01

This study compared biomechanics during stair ascent in replaced and non-replaced limbs of total knee arthroplasty (TKA) patients with control limbs of healthy participants. Thirteen TKA patients and fifteen controls performed stair ascent. Replaced and non-replaced knees of TKA patients were less flexed at contact compared to controls. The loading response peak knee extension moment was greater in control and non-replaced knees compared with replaced. The push-off peak knee abduction moment was elevated in replaced limbs compared to controls. Loading and push-off peak hip abduction moments were greater in replaced limbs compared to controls. The push-off peak hip abduction moment was greater in non-replaced limbs compared to controls. Future rehabilitation protocols should consider the replaced knee and also the non-replaced knee and surrounding joints. Copyright © 2016 Elsevier Inc. All rights reserved.

Galactic Angular Momentum in Cosmological Zoom-in Simulations. I. Disk and Bulge Components and the Galaxy-Halo Connection

NASA Astrophysics Data System (ADS)

Sokołowska, Aleksandra; Capelo, Pedro R.; Fall, S. Michael; Mayer, Lucio; Shen, Sijing; Bonoli, Silvia

2017-02-01

We investigate the angular momentum evolution of four disk galaxies residing in Milky-Way-sized halos formed in cosmological zoom-in simulations with various sub-grid physics and merging histories. We decompose these galaxies, kinematically and photometrically, into their disk and bulge components. The simulated galaxies and their components lie on the observed sequences in the j *-M * diagram, relating the specific angular momentum and mass of the stellar component. We find that galaxies in low-density environments follow the relation {j}* \\propto {M}* α past major mergers, with α ˜ 0.6 in the case of strong feedback, when bulge-to-disk ratios are relatively constant, and α ˜ 1.4 in the other cases, when secular processes operate on shorter timescales. We compute the retention factors (I.e., the ratio of the specific angular momenta of stars and dark matter) for both disks and bulges and show that they vary relatively slowly after averaging over numerous but brief fluctuations. For disks, the retention factors are usually close to unity, while for bulges, they are a few times smaller. Our simulations therefore indicate that galaxies and their halos grow in a quasi-homologous way.

Zoomed MRI Guided by Combined EEG/MEG Source Analysis: A Multimodal Approach for Optimizing Presurgical Epilepsy Work-up and its Application in a Multi-focal Epilepsy Patient Case Study.

PubMed

Aydin, Ü; Rampp, S; Wollbrink, A; Kugel, H; Cho, J -H; Knösche, T R; Grova, C; Wellmer, J; Wolters, C H

2017-07-01

In recent years, the use of source analysis based on electroencephalography (EEG) and magnetoencephalography (MEG) has gained considerable attention in presurgical epilepsy diagnosis. However, in many cases the source analysis alone is not used to tailor surgery unless the findings are confirmed by lesions, such as, e.g., cortical malformations in MRI. For many patients, the histology of tissue resected from MRI negative epilepsy shows small lesions, which indicates the need for more sensitive MR sequences. In this paper, we describe a technique to maximize the synergy between combined EEG/MEG (EMEG) source analysis and high resolution MRI. The procedure has three main steps: (1) construction of a detailed and calibrated finite element head model that considers the variation of individual skull conductivities and white matter anisotropy, (2) EMEG source analysis performed on averaged interictal epileptic discharges (IED), (3) high resolution (0.5 mm) zoomed MR imaging, limited to small areas centered at the EMEG source locations. The proposed new diagnosis procedure was then applied in a particularly challenging case of an epilepsy patient: EMEG analysis at the peak of the IED coincided with a right frontal focal cortical dysplasia (FCD), which had been detected at standard 1 mm resolution MRI. Of higher interest, zoomed MR imaging (applying parallel transmission, 'ZOOMit') guided by EMEG at the spike onset revealed a second, fairly subtle, FCD in the left fronto-central region. The evaluation revealed that this second FCD, which had not been detectable with standard 1 mm resolution, was the trigger of the seizures.

The Formation And Evolution Of Milky Way Sized Galaxies In High-Resolution Cosmological Zoom Simulations

NASA Astrophysics Data System (ADS)

Grand, Robert

2016-09-01

Simulations are playing an increasingly important role in probing the formation history of the Milky Way, including the formation of the thick/thin disc and origin of the metal distribution and chemo-dynamical relations. We introduce the Auriga project, a suite of high resolution cosmological-zoom simulations of Milky Way-sized galaxies simulated with the state-of-the-art cosmological magneto-hydrodynamical code AREPO, and present an analysis of the formation and evolution of the stellar disc(s) from early times to present day. In particular, we show that 'thickened discs' are mainly driven by a bar (if present) and interactions with satellites of masses log10 (M/ Mo ) >= 10, whereas other potential heating mechanisms such as spiral arms, radial migration, and adiabatic heating from mid-plane density growth are all sub-dominant. Interestingly, we find that even in cases of violent satellite interactions the disc reforms quickly (within a few giga years), producing a well-defined disc-bulge system. In nearly all simulations the overall structure of the disc becomes gradually more radially extended and vertically thinner with time, in support of the inside-out, upside-down formation scenario, and without the presence of a thin/thick disc dichotomy. In addition, we comment on the mass distribution of mono-abundance populations and their relation to the bulge and disc components, which are readily comparable to observations from surveys such as APOGEE and Gaia.

Improving Light Distribution by Zoom Lens for Electricity Savings in a Plant Factory with Light-Emitting Diodes.

PubMed

Li, Kun; Li, Zhipeng; Yang, Qichang

2016-01-01

The high energy consumption of a plant factory is the biggest issue in its rapid expansion, especially for lighting electricity, which has been solved to a large extent by light-emitting diodes (LED). However, the remarkable potential for further energy savings remains to be further investigated. In this study, an optical system applied just below the LED was designed. The effects of the system on the growth and photosynthesis of butterhead lettuce (Lactuca sativa var. capitata) were examined, and the performance of the optical improvement in energy savings was evaluated by comparison with the traditional LED illumination mode. The irradiation patterns used were LED with zoom lenses (Z-LED) and conventional non-lenses LED (C-LED). The seedlings in both treatments were exposed to the same light environment over the entire growth period. The improvement saved over half of the light source electricity, while prominently lowering the temperature. Influenced by this, the rate of photosynthesis sharply decreased, causing reductions in plant yield and nitrate content, while having no negative effects on morphological parameters and photosynthetic pigment contents. Nevertheless, the much higher light use efficiency of Z-LEDs makes this system a better approach to illumination in a plant factory with artificial lighting.

Improving Light Distribution by Zoom Lens for Electricity Savings in a Plant Factory with Light-Emitting Diodes

PubMed Central

Li, Kun; Li, Zhipeng; Yang, Qichang

2016-01-01

The high energy consumption of a plant factory is the biggest issue in its rapid expansion, especially for lighting electricity, which has been solved to a large extent by light-emitting diodes (LED). However, the remarkable potential for further energy savings remains to be further investigated. In this study, an optical system applied just below the LED was designed. The effects of the system on the growth and photosynthesis of butterhead lettuce (Lactuca sativa var. capitata) were examined, and the performance of the optical improvement in energy savings was evaluated by comparison with the traditional LED illumination mode. The irradiation patterns used were LED with zoom lenses (Z-LED) and conventional non-lenses LED (C-LED). The seedlings in both treatments were exposed to the same light environment over the entire growth period. The improvement saved over half of the light source electricity, while prominently lowering the temperature. Influenced by this, the rate of photosynthesis sharply decreased, causing reductions in plant yield and nitrate content, while having no negative effects on morphological parameters and photosynthetic pigment contents. Nevertheless, the much higher light use efficiency of Z-LEDs makes this system a better approach to illumination in a plant factory with artificial lighting. PMID:26904062

CLASH: Joint analysis of strong-lensing, weak-lensing shear, and magnification data for 20 galaxy clusters*

DOE PAGES

Umetsu, Keiichi; Zitrin, Adi; Gruen, Daniel; ...

2016-04-20

Here, we present a comprehensive analysis of strong-lensing, weak-lensing shear and magnification data for a sample of 16 X-ray-regular and 4 high-magnification galaxy clusters atmore » $$0.19\\lesssim z\\lesssim 0.69$$ selected from Cluster Lensing And Supernova survey with Hubble (CLASH). Our analysis combines constraints from 16-band Hubble Space Telescope observations and wide-field multi-color imaging taken primarily with Suprime-Cam on the Subaru Telescope, spanning a wide range of cluster radii (10''–16'). We reconstruct surface mass density profiles of individual clusters from a joint analysis of the full lensing constraints, and determine masses and concentrations for all of the clusters. We find the internal consistency of the ensemble mass calibration to be ≤5% ± 6% in the one-halo regime (200–2000 kpc h –1) compared to the CLASH weak-lensing-only measurements of Umetsu et al. For the X-ray-selected subsample of 16 clusters, we examine the concentration–mass (c–M) relation and its intrinsic scatter using a Bayesian regression approach. Our model yields a mean concentration of $$c{| }_{z=0.34}=3.95\\pm 0.35$$ at M200c sime 14 × 1014 M⊙ and an intrinsic scatter of $$\\sigma (\\mathrm{ln}{c}_{200{\\rm{c}}})=0.13\\pm 0.06$$, which is in excellent agreement with Λ cold dark matter predictions when the CLASH selection function based on X-ray morphological regularity and the projection effects are taken into account. We also derive an ensemble-averaged surface mass density profile for the X-ray-selected subsample by stacking their individual profiles. The stacked lensing signal is detected at 33σ significance over the entire radial range ≤4000 kpc h –1, accounting for the effects of intrinsic profile variations and uncorrelated large-scale structure along the line of sight. The stacked mass profile is well described by a family of density profiles predicted for cuspy dark-matter-dominated halos in gravitational equilibrium, namely, the

Trophic magnification of PCBs and its relationship to the octanol-water partition coefficient

USGS Publications Warehouse

Walters, D.M.; Mills, M.A.; Cade, B.S.; Burkard, L.P.

2011-01-01

We investigated polychlorinated biphenyl (PCB) bioaccumulation relative to octanol-water partition coefficient (KOW) and organism trophic position (TP) at the Lake Hartwell Superfund site (South Carolina). We measured PCBs (127 congeners) and stable isotopes (??15N) in sediment, organic matter, phytoplankton, zooplankton, macroinvertebrates, and fish. TP, as calculated from ??15N, was significantly, positively related to PCB concentrations, and food web trophic magnification factors (TMFs) ranged from 1.5-6.6 among congeners. TMFs of individual congeners increased strongly with log KOW, as did the predictive power (r2) of individual TP-PCB regression models used to calculate TMFs. We developed log KOW-TMF models for eight food webs with vastly different environments (freshwater, marine, arctic, temperate) and species composition (cold- vs warmblooded consumers). The effect of KOW on congener TMFs varied strongly across food webs (model slopes 0.0-15.0) because the range of TMFs among studies was also highly variable. We standardized TMFs within studies to mean = 0, standard deviation (SD) = 1 to normalize for scale differences and found a remarkably consistent KOW effect on TMFs (no difference in model slopes among food webs). Our findings underscore the importance of hydrophobicity (as characterized by KOW) in regulating bioaccumulation of recalcitrant compounds in aquatic systems, and demonstrate that relationships between chemical KOW and bioaccumulation from field studies are more generalized than previously recognized. ?? This article not subject to U.S. Copyright. Published 2011 by the American Chemical Society.

Trophic magnification of PCBs and Its relationship to the octanol-water partition coefficient.

PubMed

Walters, David M; Mills, Marc A; Cade, Brian S; Burkard, Lawrence P

2011-05-01

We investigated polychlorinated biphenyl (PCB) bioaccumulation relative to octanol-water partition coefficient (K(OW)) and organism trophic position (TP) at the Lake Hartwell Superfund site (South Carolina). We measured PCBs (127 congeners) and stable isotopes (δ¹⁵N) in sediment, organic matter, phytoplankton, zooplankton, macroinvertebrates, and fish. TP, as calculated from δ¹⁵N, was significantly, positively related to PCB concentrations, and food web trophic magnification factors (TMFs) ranged from 1.5-6.6 among congeners. TMFs of individual congeners increased strongly with log K(OW), as did the predictive power (r²) of individual TP-PCB regression models used to calculate TMFs. We developed log K(OW)-TMF models for eight food webs with vastly different environments (freshwater, marine, arctic, temperate) and species composition (cold- vs warmblooded consumers). The effect of K(OW) on congener TMFs varied strongly across food webs (model slopes 0.0-15.0) because the range of TMFs among studies was also highly variable. We standardized TMFs within studies to mean = 0, standard deviation (SD) = 1 to normalize for scale differences and found a remarkably consistent K(OW) effect on TMFs (no difference in model slopes among food webs). Our findings underscore the importance of hydrophobicity (as characterized by K(OW)) in regulating bioaccumulation of recalcitrant compounds in aquatic systems, and demonstrate that relationships between chemical K(OW) and bioaccumulation from field studies are more generalized than previously recognized.

Partial knee replacement - slideshow

MedlinePlus

... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series—Normal anatomy To use the sharing ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

Compact high-pulse-energy passively Q-switched Nd:YLF laser with an ultra-low-magnification unstable resonator: application for efficient optical parametric oscillator.

PubMed

Cho, C Y; Huang, Y P; Huang, Y J; Chen, Y C; Su, K W; Chen, Y F

2013-01-28

We exploit an ultra-low-magnification unstable resonator to develop a high-pulse-energy side-pumped passively Q-switched Nd:YLF/Cr⁴⁺:YAG laser with improving beam quality. A wedged laser crystal is employed in the cavity to control the emissions at 1047 nm and 1053 nm independently through the cavity alignment. The pulse energies at 1047 nm and 1053 nm are found to be 19 mJ and 23 mJ, respectively. The peak powers for both wavelengths are higher than 2 MW. Furthermore, the developed Nd:YLF lasers are employed to pump a monolithic optical parametric oscillator for confirming the applicability in nonlinear wavelength conversions.

Androgen replacement for women.

PubMed Central

Basson, R.

1999-01-01

OBJECTIVES: To determine whether a postmenopausal syndrome comprising specific changes in sexual desire and response associated with low free testosterone exists. To determine whether this syndrome is ameliorated by testosterone replacement. QUALITY OF EVIDENCE: Literature documenting that replacement of physiological levels of testosterone is beneficial and safe is scant. Only one randomized prospective blinded study examines sexual outcome in detail. MAIN MESSAGE: Testosterone is an important metabolic and sex hormone produced by the ovary throughout life. The variable reduction in ovarian testosterone production coincident with menopause is sometimes associated with a syndrome of specific changes in sexual desire and sexual response. Estrogen deficiency also impairs sexual response, but its replacement will not improve and might exacerbate sexual symptoms from androgen loss. Diagnosis of androgen deficiency is clinical, based on accurate assessment of a woman's sexual status before and after menopause and only confirmed (rather than diagnosed) by a low level of free testosterone. Partial androgen replacement restores much of the sexual response and facilitates sexual desire that is triggered by external cues. Avoiding supraphysiological levels of testosterone lessens risk of masculinization. Avoiding alkylated testosterone lessens hepatic or lipid impairment. CONCLUSION: Further prospective randomized studies of replacement of physiological levels of testosterone in women with androgen deficiency syndrome are needed, using formulations of testosterone available in Canada. The consistency of sexual changes, the associated personal and relationship distress, together with our clinical experience of the gratifying response to physiological replacement, make further studies urgently needed. PMID:10509222

Inspection of aeronautical mechanical parts with a pan-tilt-zoom camera: an approach guided by the computer-aided design model

NASA Astrophysics Data System (ADS)

Viana, Ilisio; Orteu, Jean-José; Cornille, Nicolas; Bugarin, Florian

2015-11-01

We focus on quality control of mechanical parts in aeronautical context using a single pan-tilt-zoom (PTZ) camera and a computer-aided design (CAD) model of the mechanical part. We use the CAD model to create a theoretical image of the element to be checked, which is further matched with the sensed image of the element to be inspected, using a graph theory-based approach. The matching is carried out in two stages. First, the two images are used to create two attributed graphs representing the primitives (ellipses and line segments) in the images. In the second stage, the graphs are matched using a similarity function built from the primitive parameters. The similarity scores of the matching are injected in the edges of a bipartite graph. A best-match-search procedure in the bipartite graph guarantees the uniqueness of the match solution. The method achieves promising performance in tests with synthetic data including missing elements, displaced elements, size changes, and combinations of these cases. The results open good prospects for using the method with realistic data.

Zooming in: high resolution 3D reconstruction of differently stained histological whole slide images

NASA Astrophysics Data System (ADS)

Lotz, Johannes; Berger, Judith; Müller, Benedikt; Breuhahn, Kai; Grabe, Niels; Heldmann, Stefan; Homeyer, André; Lahrmann, Bernd; Laue, Hendrik; Olesch, Janine; Schwier, Michael; Sedlaczek, Oliver; Warth, Arne

2014-03-01

Much insight into metabolic interactions, tissue growth, and tissue organization can be gained by analyzing differently stained histological serial sections. One opportunity unavailable to classic histology is three-dimensional (3D) examination and computer aided analysis of tissue samples. In this case, registration is needed to reestablish spatial correspondence between adjacent slides that is lost during the sectioning process. Furthermore, the sectioning introduces various distortions like cuts, folding, tearing, and local deformations to the tissue, which need to be corrected in order to exploit the additional information arising from the analysis of neighboring slide images. In this paper we present a novel image registration based method for reconstructing a 3D tissue block implementing a zooming strategy around a user-defined point of interest. We efficiently align consecutive slides at increasingly fine resolution up to cell level. We use a two-step approach, where after a macroscopic, coarse alignment of the slides as preprocessing, a nonlinear, elastic registration is performed to correct local, non-uniform deformations. Being driven by the optimization of the normalized gradient field (NGF) distance measure, our method is suitable for differently stained and thus multi-modal slides. We applied our method to ultra thin serial sections (2 μm) of a human lung tumor. In total 170 slides, stained alternately with four different stains, have been registered. Thorough visual inspection of virtual cuts through the reconstructed block perpendicular to the cutting plane shows accurate alignment of vessels and other tissue structures. This observation is confirmed by a quantitative analysis. Using nonlinear image registration, our method is able to correct locally varying deformations in tissue structures and exceeds the limitations of globally linear transformations.

Magnification effect of Kerr metric by configurations of collisionless particles in non-isotropic kinetic equilibria

NASA Astrophysics Data System (ADS)

Cremaschini, Claudio; Stuchlík, Zdeněk

2018-05-01

A test fluid composed of relativistic collisionless neutral particles in the background of Kerr metric is expected to generate non-isotropic equilibrium configurations in which the corresponding stress-energy tensor exhibits pressure and temperature anisotropies. This arises as a consequence of the constraints placed on single-particle dynamics by Killing tensor symmetries, leading to a peculiar non-Maxwellian functional form of the kinetic distribution function describing the continuum system. Based on this outcome, in this paper the generation of Kerr-like metric by collisionless N -body systems of neutral matter orbiting in the field of a rotating black hole is reported. The result is obtained in the framework of covariant kinetic theory by solving the Einstein equations in terms of an analytical perturbative treatment whereby the gravitational field is decomposed as a prescribed background metric tensor described by the Kerr solution plus a self-field correction. The latter one is generated by the uncharged fluid at equilibrium and satisfies the linearized Einstein equations having the non-isotropic stress-energy tensor as source term. It is shown that the resulting self-metric is again of Kerr type, providing a mechanism of magnification of the background metric tensor and its qualitative features.

Analytic relations for magnifications and time delays in gravitational lenses with fold and cusp configurations

NASA Astrophysics Data System (ADS)

Congdon, Arthur B.; Keeton, Charles R.; Nordgren, C. Erik

2008-09-01

Gravitational lensing provides a unique and powerful probe of the mass distributions of distant galaxies. Four-image lens systems with fold and cusp configurations have two or three bright images near a critical point. Within the framework of singularity theory, we derive analytic relations that are satisfied for a light source that lies a small but finite distance from the astroid caustic of a four-image lens. Using a perturbative expansion of the image positions, we show that the time delay between the close pair of images in a fold lens scales with the cube of the image separation, with a constant of proportionality that depends on a particular third derivative of the lens potential. We also apply our formalism to cusp lenses, where we develop perturbative expressions for the image positions, magnifications and time delays of the images in a cusp triplet. Some of these results were derived previously for a source asymptotically close to a cusp point, but using a simplified form of the lens equation whose validity may be in doubt for sources that lie at astrophysically relevant distances from the caustic. Along with the work of Keeton, Gaudi & Petters, this paper demonstrates that perturbation theory plays an important role in theoretical lensing studies.

Carbohydrates as Fat Replacers.

PubMed

Peng, Xingyun; Yao, Yuan

2017-02-28

The overconsumption of dietary fat contributes to various chronic diseases, which encourages attempts to develop and consume low-fat foods. Simple fat reduction causes quality losses that impede the acceptance of foods. Fat replacers are utilized to minimize the quality deterioration after fat reduction or removal to achieve low-calorie, low-fat claims. In this review, the forms of fats and their functions in contributing to food textural and sensory qualities are discussed in various food systems. The connections between fat reduction and quality loss are described in order to clarify the rationales of fat replacement. Carbohydrate fat replacers usually have low calorie density and provide gelling, thickening, stabilizing, and other texture-modifying properties. In this review, carbohydrates, including starches, maltodextrins, polydextrose, gums, and fibers, are discussed with regard to their interactions with other components in foods as well as their performances as fat replacers in various systems.

Estrogen and Progestin (Hormone Replacement Therapy)

MedlinePlus

... progestin are two female sex hormones. Hormone replacement therapy works by replacing estrogen hormone that is no ... Progestin is added to estrogen in hormone replacement therapy to reduce the risk of uterine cancer in ...

Elbow replacement

MedlinePlus

... arthroplasty Patient Instructions Elbow replacement - discharge Surgical wound care - open Images Elbow prosthesis References Cohen MS, Chen NC. Total elbow arthroplasty. In: Wolfe SW, Hotchkiss RN, Pederson ...

Processing the Army’s Wartime Replacements: The Preferred CONUS Replacement Center Concept.

DTIC Science & Technology

1987-12-01

Replacement System. The first model, the macro model, was a network flow model which was used to analyze the flow of replacements from their source through...individual CRCs. Through the analysis of the macro model, recommendations were made on how the CRC system should be configured in terms of size, location

Knee Replacement - Multiple Languages

MedlinePlus

... in a new window. Arabic (العربية) Expand Section Total Knee Replacement - العربية (Arabic) Bilingual PDF Health Information Translations Chinese, Simplified (Mandarin dialect) (简体中文) Expand Section Total Knee Replacement - 简体中文 (Chinese, Simplified (Mandarin dialect)) Bilingual PDF Health ...

Hormone replacement therapy in the developing countries.

PubMed

Oei, P L; Ratnam, S S

1998-05-01

The sales data of oestrogen replacement products for 8 developing countries from 1993 to 1995 were analyzed. The data from Malaysia, Pakistan, Taiwan, Thailand, Indonesia, Philippines and South Korea showed the increasing use of oestrogen replacement products. The total usage however varied widely, from only US$11,153 (Philippines in 1993) to as much as US$6,306,717 (Taiwan in 1995). In Singapore, where oestrogen replacement is an accepted and established form of therapy for the postmenopausal woman, there has been an increase in the usage of the nonoestrogen replacement products. There are multiple reasons for the increasing sales of hormone replacement products in the developing countries and these are explored in this article. In some of the developing countries, for example China and India, hormone replacement therapy has just been introduced. However, in those developing countries in which hormone replacement therapy is already available, sales figures show increasing usage. The future augurs well for hormone replacement therapy.

22 CFR 51.10 - Replacement passports.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Replacement passports. 51.10 Section 51.10 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS General § 51.10 Replacement passports. A passport issuing office may issue a replacement passport without payment of applicable fees for...

22 CFR 51.10 - Replacement passports.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Replacement passports. 51.10 Section 51.10 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS General § 51.10 Replacement passports. A passport issuing office may issue a replacement passport without payment of applicable fees for...

22 CFR 51.10 - Replacement passports.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Replacement passports. 51.10 Section 51.10 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS General § 51.10 Replacement passports. A passport issuing office may issue a replacement passport without payment of applicable fees for...

22 CFR 51.10 - Replacement passports.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Replacement passports. 51.10 Section 51.10 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS General § 51.10 Replacement passports. A passport issuing office may issue a replacement passport without payment of applicable fees for...

22 CFR 51.10 - Replacement passports.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Replacement passports. 51.10 Section 51.10 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS General § 51.10 Replacement passports. A passport issuing office may issue a replacement passport without payment of applicable fees for...

Mechanical valve replacement in congenital heart disease.

PubMed

Fiane, A E; Lindberg, H L; Saatvedt, K; Svennevig, J L

1996-05-01

Mechanical valves are the prosthesis of choice in valve replacement in children. However, the problem of somatic growth leading to patient-valve mismatch remains present, and the appropriate anticoagulation regimen remains controversial. We present our experience of valve replacement in a young population over 20 years. Between 1972 and 1992, 48 patients (34 males and 14 females), mean age 11.2 years (range 0.4-27.4 years), underwent mechanical valve replacement at our institution. Aortic valve replacement was performed in 28 patients (58.3%), mitral valve replacement in 13 (27.1%), tricuspid valve replacement in six (12.5%) and pulmonary valve replacement in one patient (2.1%). The prostheses used were: St. Jude Medical (n = 2), Björk-Shiley (n = 14), Medtronic Hall (n = 16), Duromedics (n = 2) and CarboMedics (n = 14). Early mortality was 14.3%, 10.7% for aortic valve replacement and 30.8% for mitral valve replacement. Mean follow up for all patients was 8.3 years (range 0-22 years), with a total of 398 patient-years. Seven patients died during the follow up (17.1%). Survival after 10 years, including operative mortality, was 81% for aortic valve replacement, 33% for mitral valve replacement, 83% for tricuspid valve replacement and 100% for pulmonary valve replacement. All patients were anticoagulated with warfarin. In eight patients (16.7%) an antiplatelet drug (aspirin or dipyridamole) was added. Major events included paravalvular leak in six patients (1.5%/pty), valve thrombosis in five (mitral position in two, tricuspid in three) (1.3%/pty) and endocarditis in one patient (0.3%/pty). Minor thromboembolic events occurred in three patients (0.8%/pty) and minor hemorrhagic events in three (0.8%/pty). No patients developed hemolytic anemia and there was no case of structural failure. In our experience, mechanical prostheses in congenital heart disease were associated with significant morbidity and mortality, however long term survival after aortic valve

Long-life slab replacement concrete.

DOT National Transportation Integrated Search

2015-03-01

This research was initiated following reports of high incidence of cracking on FDOT concrete pavement replacement : slab projects. Field slabs were instrumented for data acquisition from high-early-strength concrete pavement : replacement slabs place...

Subcutaneous ICD screening with the Boston Scientific ZOOM programmer versus a 12-lead ECG machine.

PubMed

Chang, Shu C; Patton, Kristen K; Robinson, Melissa R; Poole, Jeanne E; Prutkin, Jordan M

2018-02-24

The subcutaneous implantable cardioverter-defibrillator (S-ICD) requires preimplant screening to ensure appropriate sensing and reduce risk of inappropriate shocks. Screening can be performed using either an ICD programmer or a 12-lead electrocardiogram (ECG) machine. It is unclear whether differences in signal filtering and digital sampling change the screening success rate. Subjects were recruited if they had a transvenous single-lead ICD without pacing requirements or were candidates for a new ICD. Screening was performed using both a Boston Scientific ZOOM programmer (Marlborough, MA, USA) and General Electric MAC 5000 ECG machine (Fairfield, CT, USA). A pass was defined as having at least one lead that fit within the screening template in both supine and sitting positions. A total of 69 subjects were included and 27 sets of ECG leads had differing screening results between the two machines (7%). Of these sets, 22 (81%) passed using the ECG machine but failed using the programmer and five (19%) passed using the ECG machine but failed using the programmer (P < 0.001). Four subjects (6%) passed screening using the ECG machine but failed using the programmer. No subject passed screening with the programmer but failed with the ECG machine. There can be occasional disagreement in S-ICD patient screening between an ICD programmer and ECG machine, all of whom passed with the ECG machine but failed using the programmer. On a per lead basis, the ECG machine passes more subjects. It is unknown what the inappropriate shock rate would be if an S-ICD was implanted. Clinical judgment should be used in borderline cases. © 2018 Wiley Periodicals, Inc.

Shoulder replacement

MedlinePlus

... the opening at the end of the shoulder blade, called the socket. This type of joint allows ... head. The socket part (glenoid) of your shoulder blade will be replaced with a smooth plastic shell ( ...

MDCA Needle 1 Replacement

NASA Image and Video Library

2013-04-22

ISS035-E-025557(22 April 2013) ---Multi-user Droplet Combustion Apparatus (MDCA) Hardware Replacement: Cassidy accessed the Combustion Integration Rack (CIR) Combustion Chamber and removed the MDCA Chamber Insert Assembly (CIA). He then replaced the MDCA Needle 1 due to a fuel line that was damaged during previous activities when the MDCA CIA was being removed from the Combustion Chamber.

Acoustic emission and magnification of atomic lines resolution for laser breakdown of salt water in ultrasound field

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

Bulanov, Alexey V., E-mail: a-bulanov@me.com; V.I. Il’ichev Pacific Oceanological Institute, Vladivostok, Russia 690041; Nagorny, Ivan G., E-mail: ngrn@mail.ru

Researches of the acoustic effects accompanying optical breakdown in a water, generated by the focused laser radiation with power ultrasound have been carried out. Experiments were performed by using 532 nm pulses from Brilliant B Nd:YAG laser. Acoustic radiation was produced by acoustic focusing systems in the form hemisphere and ring by various resonance frequencies of 10.7 kHz and 60 kHz. The experimental results are obtained, that show the sharply strengthens effects of acoustic emission from a breakdown zone by the joint influence of a laser and ultrasonic irradiation. Essentially various thresholds of breakdown and character of acoustic emission inmore » fresh and sea water are found out. The experimental result is established, testifying that acoustic emission of optical breakdown of sea water at presence and at absence of ultrasound essentially exceeds acoustic emission in fresh water. Atomic lines of some chemical elements like a Sodium, Magnesium and so on were investigated for laser breakdown of water with ultrasound field. The effect of magnification of this lines resolution for salt water in ultrasound field was obtained.« less

Knee Replacement

MedlinePlus

... a knee replacement is right for you, an orthopedic surgeon assesses your knee's range of motion, stability ... trademarks of Mayo Foundation for Medical Education and Research. © 1998-2018 Mayo Foundation for Medical Education and ...

Local heat treatment of high strength steels with zoom-optics and 10kW-diode laser

NASA Astrophysics Data System (ADS)

Baumann, Markus; Krause, Volker; Bergweiler, Georg; Flaischerowitz, Martin; Banik, Janko

2012-03-01

High strength steels enable new solutions for weight optimized car bodies without sacrificing crash safety. However, cold forming of these steels is limited due to the need of high press capacity, increased tool wear, and limitations in possible geometries. One can compensate for these drawbacks by local heat treatment of the blanks. In high-deformation areas the strength of the material is reduced and the plasticity is increased by diode laser irradiation. Local heat treatment with diode laser radiation could also yield key benefits for the applicability of press hardened parts. High strength is not desired all over the part. Joint areas or deformation zones for requested crash properties require locally reduced strength. In the research project "LOKWAB" funded by the German Federal Ministry of Education and Research (BMBF), heat treatment of high strength steels was investigated in cooperation with Audi, BMW, Daimler, ThyssenKrupp, Fraunhofer- ILT, -IWU and others. A diode laser with an output power of 10 kW was set up to achieve acceptable process speed. Furthermore a homogenizing zoom-optics was developed, providing a rectangular focus with homogeneous power density. The spot size in x- and y-direction can be changed independently during operation. With pyrometer controlled laser power the surface temperature is kept constant, thus the laser treated zone can be flexibly adapted to the needs. Deep-drawing experiments show significant improvement in formability. With this technique, parts can be manufactured, which can conventionally only be made of steel with lower strength. Locally reduced strength of press hardened serial parts was demonstrated.

Biological tooth replacement

PubMed Central

Sartaj, Rachel; Sharpe, Paul

2006-01-01

Teeth develop from a series of reciprocal interactions that take place between epithelium and mesenchyme during development of the mouth that begin early in mammalian embryogenesis. The molecular control of key processes in tooth development such as initiation, morphogenesis and cytodifferentiation are being increasingly better understood, to the point where this information can be used as the basis for approaches to produce biological replacement teeth (BioTeeth). This review outlines the current approaches, ideas and progress towards the production of BioTeeth that could form an alternative method for replacing lost or damaged teeth. PMID:17005022

Ice crystal growth in a dynamic thermal diffusion chamber

NASA Technical Reports Server (NTRS)

Keller, V. W.

1980-01-01

Ice crystals were grown in a supersaturated environment produced by a dynamic thermal diffusion chamber, which employed two horizontal plates separated by a distance of 2.5 cm. Air was circulated between and along the 1.2 m length of the plates past ice crystals which nucleated and grew from a fiber suspended vertically between the two plates. A zoom stereo microscope with a magnification which ranged from 3X to 80X and both 35 mm still photographs and 16 mm time lapse cine films taken through the microscope were used to study the variation of the shape and linear growth rate of ice crystals as a function of the ambient temperature, the ambient supersaturation, and the forced ventilation velocity. The ambient growth conditions were varied over the range of temperature 0 to -40 C, over the range of supersaturation 4% to 50% with respect to ice, and over the range of forced ventilation velocities 0 cm/s to 20 cm/s.

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

PubMed

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

2013-04-01

The primary visual area (V1) forms a systematic map of the visual field, in which adjacent cell clusters represent adjacent points of visual space. A precise quantification of this map is key to understanding the anatomical relationships between neurons located in different stations of the visual pathway, as well as the neural bases of visual performance in different regions of the visual field. We used computational methods to quantify the visual topography of V1 in the marmoset (Callithrix jacchus), a small diurnal monkey. The receptive fields of neurons throughout V1 were mapped in two anesthetized animals using electrophysiological recordings. Following histological reconstruction, precise 3D reconstructions of the V1 surface and recording sites were generated. We found that the areal magnification factor (M(A) ) decreases with eccentricity following a function that has the same slope as that observed in larger diurnal primates, including macaque, squirrel, and capuchin monkeys, and humans. However, there was no systematic relationship between M(A) and polar angle. Despite individual variation in the shape of V1, the relationship between M(A) and eccentricity was preserved across cases. Comparison between V1 and the retinal ganglion cell density demonstrated preferential magnification of central space in the cortex. The size of the cortical compartment activated by a punctiform stimulus decreased from the foveal representation towards the peripheral representation. Nonetheless, the relationship between the receptive field sizes of V1 cells and the density of ganglion cells suggested that each V1 cell receives information from a similar number of retinal neurons, throughout the visual field. Copyright © 2012 Wiley Periodicals, Inc.

Lipid reserve dynamics and magnification of persistent organic pollutants in spawning sockeye salmon (Oncorhynchus nerka) from the Fraser River, British Columbia.

PubMed

Kelly, Barry C; Gray, Samantha L; Ikonomou, Michael G; Macdonald, J Steve; Bandiera, Stelvio M; Hrycay, Eugene G

2007-05-01

Pacific sockeye salmon (Oncorhynchus nerka) can travel several hundred kilometers to reach native spawning grounds and fulfill semelparous reproduction. The dramatic changes in lipid reserves during upstream migration can greatly affect internal toxicokinetics of persistent organic pollutants (POPs) such as PCBs, PCDDs, and PCDFs. We measured lipid content changes and contaminant concentrations in tissues (liver, muscle, roe/gonads) and biomarker responses (ethoxyresorufin O-deethylase or EROD activity and CYP1A levels) in two Pacific sockeye salmon stocks sampled at several locations along their spawning migration in the Fraser River, British Columbia. Muscle lipid contents declined significantly with increasing upstream migration distance and corresponded to elevated lipid normalized concentrations of PCBs and PCDD/Fs in spawning sockeye. Post-migration magnification factors (MFs) in spawning sockeye ranged between 3 and 12 and were comparable to model-predicted MFs. sigmaPCBs(150-500 ng x g(-1) lipid), sigmaPCDD/Fs (1-1000 pg x g(-1) lipid) and 2,3,7,8-TCDD toxic equivalent or TEQ levels (0.1-15 pg x g(-1) lipid) in spawning sockeye were relatively low and did not affect hepatic EROD activity/CYP1A induction. Despite a 3-fold magnification, TEQ levels in eggs of spawning Fraser River sockeye did not exceed 0.3 pg x g(-1) wet wt, a threshold level associated with 30% egg mortality in salmonids. PCBs in Fraser River sockeye are comparable to previous levels in Pacific sockeye. In contrast to Pacific sockeye from more remote coastal locations, PCDDs and PCDFs in Fraser River sockeye were generally minor components (<25%) of TEQ levels, compared to dioxin like PCB contributions (>75%). The data suggest that (i) the Fraser River is not a major contamination source of PCBs or PCDD/Fs and (ii) marine contaminant distribution, food-chain dynamics, and ocean-migration pathway are likely important factors controlling levels and patterns of POPs in returning Pacific

Prioritizing equipment for replacement.

PubMed

Capuano, Mike

2010-01-01

It is suggested that clinical engineers take the lead in formulating evaluation processes to recommend equipment replacement. Their skill, knowledge, and experience, combined with access to equipment databases, make them a logical choice. Based on ideas from Fennigkoh's scheme, elements such as age, vendor support, accumulated maintenance cost, and function/risk were used.6 Other more subjective criteria such as cost benefits and efficacy of newer technology were not used. The element of downtime was also omitted due to the data element not being available. The resulting Periop Master Equipment List and its rationale was presented to the Perioperative Services Program Council. They deemed the criteria to be robust and provided overwhelming acceptance of the list. It was quickly put to use to estimate required capital funding, justify items already thought to need replacement, and identify high-priority ranked items for replacement. Incorporating prioritization criteria into an existing equipment database would be ideal. Some commercially available systems do have the basic elements of this. Maintaining replacement data can be labor-intensive regardless of the method used. There is usually little time to perform the tasks necessary for prioritizing equipment. However, where appropriate, a clinical engineering department might be able to conduct such an exercise as shown in the following case study.

Prioritization methodology for chemical replacement

NASA Technical Reports Server (NTRS)

Cruit, Wendy; Goldberg, Ben; Schutzenhofer, Scott

1995-01-01

Since United States of America federal legislation has required ozone depleting chemicals (class 1 & 2) to be banned from production, The National Aeronautics and Space Administration (NASA) and industry have been required to find other chemicals and methods to replace these target chemicals. This project was initiated as a development of a prioritization methodology suitable for assessing and ranking existing processes for replacement 'urgency.' The methodology was produced in the form of a workbook (NASA Technical Paper 3421). The final workbook contains two tools, one for evaluation and one for prioritization. The two tools are interconnected in that they were developed from one central theme - chemical replacement due to imposed laws and regulations. This workbook provides matrices, detailed explanations of how to use them, and a detailed methodology for prioritization of replacement technology. The main objective is to provide a GUIDELINE to help direct the research for replacement technology. The approach for prioritization called for a system which would result in a numerical rating for the chemicals and processes being assessed. A Quality Function Deployment (QFD) technique was used in order to determine numerical values which would correspond to the concerns raised and their respective importance to the process. This workbook defines the approach and the application of the QFD matrix. This technique: (1) provides a standard database for technology that can be easily reviewed, and (2) provides a standard format for information when requesting resources for further research for chemical replacement technology. Originally, this workbook was to be used for Class 1 and Class 2 chemicals, but it was specifically designed to be flexible enough to be used for any chemical used in a process (if the chemical and/or process needs to be replaced). The methodology consists of comparison matrices (and the smaller comparison components) which allow replacement technology

Permanent Quadriplegia Following Replacement of Voice Prosthesis.

PubMed

Ozturk, Kayhan; Erdur, Omer; Kibar, Ertugrul

2016-11-01

The authors presented a patient with quadriplegia caused by cervical spine abscess following voice prosthesis replacement. The authors present the first reported permanent quadriplegia patient caused by voice prosthesis replacement. The authors wanted to emphasize that life-threatening complications may be faced during the replacement of voice prosthesis. Care should be taken during the replacement of voice prosthesis and if some problems have been faced during the procedure patients must be followed closely.

25 CFR 700.189 - Expenditure of replacement home benefits.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 25 Indians 2 2011-04-01 2011-04-01 false Expenditure of replacement home benefits. 700.189 Section... PROCEDURES Replacement Housing Payments § 700.189 Expenditure of replacement home benefits. Replacement home... maximum replacement home benefit. (b) All replacement home benefits shall be expended not later than one...

25 CFR 700.189 - Expenditure of replacement home benefits.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 25 Indians 2 2014-04-01 2014-04-01 false Expenditure of replacement home benefits. 700.189 Section... PROCEDURES Replacement Housing Payments § 700.189 Expenditure of replacement home benefits. Replacement home... maximum replacement home benefit. (b) All replacement home benefits shall be expended not later than one...

25 CFR 700.189 - Expenditure of replacement home benefits.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 25 Indians 2 2012-04-01 2012-04-01 false Expenditure of replacement home benefits. 700.189 Section... PROCEDURES Replacement Housing Payments § 700.189 Expenditure of replacement home benefits. Replacement home... maximum replacement home benefit. (b) All replacement home benefits shall be expended not later than one...

25 CFR 700.189 - Expenditure of replacement home benefits.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 2 2010-04-01 2010-04-01 false Expenditure of replacement home benefits. 700.189 Section... PROCEDURES Replacement Housing Payments § 700.189 Expenditure of replacement home benefits. Replacement home... maximum replacement home benefit. (b) All replacement home benefits shall be expended not later than one...

25 CFR 700.189 - Expenditure of replacement home benefits.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 25 Indians 2 2013-04-01 2013-04-01 false Expenditure of replacement home benefits. 700.189 Section... PROCEDURES Replacement Housing Payments § 700.189 Expenditure of replacement home benefits. Replacement home... maximum replacement home benefit. (b) All replacement home benefits shall be expended not later than one...

"Leopard skin sign": the use of narrow-band imaging with magnification endoscopy in celiac disease.

PubMed

Tchekmedyian, Asadur J; Coronel, Emmanuel; Czul, Frank

2014-01-01

Celiac Disease (CD) is an immune reaction to gluten containing foods such as rye, wheat and barley. This condition affects individuals with a genetic predisposition; it targets the small bowel and may cause symptoms including diarrhea, malabsorption, weight loss, abdominal pain and bloating. The diagnosis is made by serologic testing of celiac-specific antibodies and confirmed by histology. Certain endoscopic characteristics, such as scalloping, reduction in the number of folds, mosaic-pattern mucosa or nodular mucosa, are suggestive of CD and can be visualized under white light endoscopy. Due to its low sensitivity, endoscopy alone is not recommended to diagnose CD; however, enhanced visual identification of suspected mucosal abnormalities through the use of new technologies, such as narrow band imaging with magnification (NBI-ME), could assist in targeting biopsies and thereby increasing the sensitivity of endoscopy. This is a case series of seven patients with serologic and histologic diagnoses of CD who underwent upper endoscopies with NBI-ME imaging technology as part of their CD evaluation. By employing this imaging technology, we could identify patchy atrophy sites in a mosaic pattern, with flattened villi and alteration of the central capillaries of the duodenal mucosa. We refer to this epithelial pattern as "Leopard Skin Sign". Since epithelial lesions are easily seen using NBI-ME, we found it beneficial for identifying and targeting biopsy sites. Larger prospective studies are warranted to confirm our findings.

The management of failed ankle replacement.

PubMed

Kotnis, R; Pasapula, C; Anwar, F; Cooke, P H; Sharp, R J

2006-08-01

Advances in the design of the components for total ankle replacement have led to a resurgence of interest in this procedure. Between January 1999 and December 2004, 16 patients with a failed total ankle replacement were referred to our unit. In the presence of infection, a two-stage salvage procedure was planned. The first involved the removal of the components and the insertion of a cement spacer. Definitive treatment options included hindfoot fusion with a circular frame or amputation. When there was no infection, a one-stage salvage procedure was planned. Options included hindfoot fusion with an intramedullary nail or revision total ankle replacement. When there was suspicion of infection, a percutaneous biopsy was performed. The patients were followed up for a minimum of 12 months. Of the 16 patients, 14 had aseptic loosening, five of whom underwent a revision total ankle replacement and nine a hindfoot fusion. Of the two with infection, one underwent fusion and the other a below-knee amputation. There were no cases of wound breakdown, nonunion or malunion. Management of the failed total ankle replacement should be performed by experienced surgeons and ideally in units where multidisciplinary support is available. Currently, a hindfoot fusion appears to be preferable to a revision total ankle replacement.

Digital hologram transformations for RGB color holographic display with independent image magnification and translation in 3D.

PubMed

Makowski, Piotr L; Zaperty, Weronika; Kozacki, Tomasz

2018-01-01

A new framework for in-plane transformations of digital holograms (DHs) is proposed, which provides improved control over basic geometrical features of holographic images reconstructed optically in full color. The method is based on a Fourier hologram equivalent of the adaptive affine transformation technique [Opt. Express18, 8806 (2010)OPEXFF1094-408710.1364/OE.18.008806]. The solution includes four elementary geometrical transformations that can be performed independently on a full-color 3D image reconstructed from an RGB hologram: (i) transverse magnification; (ii) axial translation with minimized distortion; (iii) transverse translation; and (iv) viewing angle rotation. The independent character of transformations (i) and (ii) constitutes the main result of the work and plays a double role: (1) it simplifies synchronization of color components of the RGB image in the presence of mismatch between capture and display parameters; (2) provides improved control over position and size of the projected image, particularly the axial position, which opens new possibilities for efficient animation of holographic content. The approximate character of the operations (i) and (ii) is examined both analytically and experimentally using an RGB circular holographic display system. Additionally, a complex animation built from a single wide-aperture RGB Fourier hologram is presented to demonstrate full capabilities of the developed toolset.

Zooming into the Paraná-Etendeka silicic volcanics, southern Brasil: a physical volcanological approach

NASA Astrophysics Data System (ADS)

Gualda, G. A. R.; Gravley, D. M.; Harmon, L. J.; Tramontano, S.; Luchetti, A. C. F.; Nardy, A.

2015-12-01

Paraná-Etendeka volcanism led to the opening of the Atlantic Ocean during the early Cretaceous. Most Paraná research has focused on the regional scale geochemistry and geochronology. Complementarily, we have taken a physical volcanological approach to elucidate the styles and locations of silicic eruptions with a focus on extrusive vs. explosive varieties, and an ultimate goal to characterise the crustal magmatic conditions. Through satellite to microscopic observations we can zoom from volcanic edifice and deposit morphologies, remarkably preserved in the Mesozoic landscape, to primary microscopic textures. Lava domes appear in clusters with high relief and are surrounded by lower flat-topped terraces comprised of multiple tabular-shaped packages with conspicuous horizontal jointing. Joint thickness coincides with layering from mm-scale laminations to larger lens-shaped blobs up to 20 cm thick and more than a metre long. These layered deposits appear to be compressed and/or stretched into the finer laminations and grade up into the fatter lens-shaped blobs. In other regions, extensive plateaus dominate the landscape with flat-lying flow packages continuous over 10's of kilometres and possibly further. Rheomorphism is evident in places with sub-parallel joints that grade up into a zone of deformation where curvilinear to overturned joint patterns reflect lateral forcing in a more ductile flow regime. Microscopically the blobs and surrounding matrix are almost indistinguishable except for subtle differences in spherulite textures, zonal alteration and distribution of crystal sizes. Although our research is relatively nascent, our observations suggest eruptions may have ranged from edifice building effusive ones to more explosive ones, albeit possibly relatively low fire fountains feeding hybridised lava/pyroclastic flows. Some of these flows are extensive, tens to possibly hundreds of kilometres long, consistent with high eruption rates of hot magma. These

Management of the failed biaxial wrist replacement.

PubMed

Talwalkar, S C; Hayton, M J; Trail, I A; Stanley, J K

2005-06-01

Nine cases of failed biaxial wrist replacement underwent revision surgery and subsequent clinical and radiographic assessment at a mean follow-up of 28 months. Clinical assessment included the hospital for special surgery (HSS) and activities of daily living scoring systems. Five patients had a revision biaxial wrist replacement, three had wrist fusions and two underwent an excision arthroplasty. The mean HSS score was 73 for the revision biaxial replacements, 63 for the wrist fusions and 92 for the excision arthroplasties. The mean activities for daily living score was 16 for the revision biaxial replacements, 14 for the wrist fusion and 20 for the excision arthroplasties. Despite the experience of implant failure, six patients would still choose a primary wrist replacement again. All patients in this small series appear to have had good clinical outcomes. Revision to another wrist replacement appears no worse than a wrist fusion in the short term and patients value the preservation of movement that an implant offers.

25 CFR 700.53 - Dwelling, replacement.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Policies and Instructions Definitions § 700.53 Dwelling, replacement. The term replacement dwelling means a... unreasonable adverse environmental conditions from either natural or man-made sources and in an area not...

Molecular replacement: tricks and treats

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

Abergel, Chantal, E-mail: chantal.abergel@igs.cnrs-mrs.fr

2013-11-01

To be successful, molecular replacement relies on the quality of the model and of the crystallographic data. Some tricks that could be applied to the models or to the crystal to increase the success rate of MR are discussed here. Molecular replacement is the method of choice for X-ray crystallographic structure determination provided that suitable structural homologues are available in the PDB. Presently, there are ∼80 000 structures in the PDB (8074 were deposited in the year 2012 alone), of which ∼70% have been solved by molecular replacement. For successful molecular replacement the model must cover at least 50% ofmore » the total structure and the C{sub α} r.m.s.d. between the core model and the structure to be solved must be less than 2 Å. Here, an approach originally implemented in the CaspR server (http://www.igs.cnrs-mrs.fr/Caspr2/index.cgi) based on homology modelling to search for a molecular-replacement solution is discussed. How the use of as much information as possible from different sources can improve the model(s) is briefly described. The combination of structural information with distantly related sequences is crucial to optimize the multiple alignment that will define the boundaries of the core domains. PDB clusters (sequences with ≥30% identical residues) can also provide information on the eventual changes in conformation and will help to explore the relative orientations assumed by protein subdomains. Normal-mode analysis can also help in generating series of conformational models in the search for a molecular-replacement solution. Of course, finding a correct solution is only the first step and the accuracy of the identified solution is as important as the data quality to proceed through refinement. Here, some possible reasons for failure are discussed and solutions are proposed using a set of successful examples.« less

21 CFR 870.3925 - Replacement heart valve.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Replacement heart valve. 870.3925 Section 870.3925...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3925 Replacement heart valve. (a) Identification. A replacement heart valve is a device intended to perform the function of any...

40 CFR 1042.615 - Replacement engine exemption.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Replacement engine exemption. 1042.615... CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION ENGINES AND VESSELS Special Compliance Provisions § 1042.615 Replacement engine exemption. For Category 1 and Category 2 replacement...

40 CFR 1042.615 - Replacement engine exemption.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Replacement engine exemption. 1042.615... CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION ENGINES AND VESSELS Special Compliance Provisions § 1042.615 Replacement engine exemption. For Category 1 and Category 2 replacement...

21 CFR 870.3925 - Replacement heart valve.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Replacement heart valve. 870.3925 Section 870.3925...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3925 Replacement heart valve. (a) Identification. A replacement heart valve is a device intended to perform the function of any...

21 CFR 870.3925 - Replacement heart valve.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Replacement heart valve. 870.3925 Section 870.3925...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3925 Replacement heart valve. (a) Identification. A replacement heart valve is a device intended to perform the function of any...

21 CFR 870.3925 - Replacement heart valve.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Replacement heart valve. 870.3925 Section 870.3925...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3925 Replacement heart valve. (a) Identification. A replacement heart valve is a device intended to perform the function of any...

21 CFR 870.3925 - Replacement heart valve.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Replacement heart valve. 870.3925 Section 870.3925...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3925 Replacement heart valve. (a) Identification. A replacement heart valve is a device intended to perform the function of any...

40 CFR 85.1714 - Replacement-engine exemption.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Replacement-engine exemption. 85.1714... Vehicle Engines § 85.1714 Replacement-engine exemption. (a) Engine manufacturers may use the provisions of 40 CFR 1068.240 to exempt new replacement heavy-duty highway engines as specified in this section. (b...

40 CFR 85.1714 - Replacement-engine exemption.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Replacement-engine exemption. 85.1714... Vehicle Engines § 85.1714 Replacement-engine exemption. (a) Engine manufacturers may use the provisions of 40 CFR 1068.240 to exempt new replacement heavy-duty highway engines as specified in this section. (b...

40 CFR 85.1714 - Replacement-engine exemption.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Replacement-engine exemption. 85.1714... Vehicle Engines § 85.1714 Replacement-engine exemption. (a) Engine manufacturers may use the provisions of 40 CFR 1068.240 to exempt new replacement heavy-duty highway engines as specified in this section. (b...

40 CFR 85.1714 - Replacement-engine exemption.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Replacement-engine exemption. 85.1714... Vehicle Engines § 85.1714 Replacement-engine exemption. (a) Engine manufacturers may use the provisions of 40 CFR 1068.240 to exempt new replacement heavy-duty highway engines as specified in this section. (b...

40 CFR 85.1714 - Replacement-engine exemption.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Replacement-engine exemption. 85.1714... Vehicle Engines § 85.1714 Replacement-engine exemption. (a) Engine manufacturers may use the provisions of 40 CFR 1068.240 to exempt new replacement heavy-duty highway engines as specified in this section. (b...

Homologous gene replacement in Physarum

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

Burland, T.G.; Pallotta, D.

1995-01-01

The protist Physarum polycephalum is useful for analysis of several aspects of cellular and developmental biology. To expand the opportunities for experimental analysis of this organism, we have developed a method for gene replacement. We transformed Physarum amoebae with plasmid DNA carrying a mutant allele, ardD{Delta}1, of the ardD actin gene; ardD{Delta}1 mutates the critical carboxy-terminal region of the gene product. Because ardD is not expressed in the amoeba, replacement of ardD{sup +} with ardD{Delta}1 should not be lethal for this cell type. Transformants were obtained only when linear plasmid DNA was used. Most transformants carried one copy of ardD{Delta}1more » in addition to ardD{sup +}, but in two (5%), ardD{sup +} was replaced by a single copy of ardD{Delta}1. This is the first example of homologous gene replacement in Physarum. ardD{Delta}1 was stably maintained in the genome through growth, development and meiosis. We found no effect of ardD{Delta}l on viability, growth, or development of any of the various cell types of Physarum. Thus, the carboxy-terminal region of the ardD product appears not to perform a unique essential role in growth or development. Nevertheless, this method for homologous gene replacement can be applied to analyze the function of any cloned gene. 38 refs., 6 figs., 1 tab.« less

43 CFR 4750.4-4 - Replacement animals.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Replacement animals. 4750.4-4 Section 4750... FREE-ROAMING HORSES AND BURROS Private Maintenance § 4750.4-4 Replacement animals. The authorized officer shall replace an animal, upon request by the adopter, if (a) within 6 months of the execution of...

43 CFR 4750.4-4 - Replacement animals.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Replacement animals. 4750.4-4 Section 4750... FREE-ROAMING HORSES AND BURROS Private Maintenance § 4750.4-4 Replacement animals. The authorized officer shall replace an animal, upon request by the adopter, if (a) within 6 months of the execution of...

43 CFR 4750.4-4 - Replacement animals.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Replacement animals. 4750.4-4 Section 4750... FREE-ROAMING HORSES AND BURROS Private Maintenance § 4750.4-4 Replacement animals. The authorized officer shall replace an animal, upon request by the adopter, if (a) within 6 months of the execution of...

43 CFR 4750.4-4 - Replacement animals.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Replacement animals. 4750.4-4 Section 4750... FREE-ROAMING HORSES AND BURROS Private Maintenance § 4750.4-4 Replacement animals. The authorized officer shall replace an animal, upon request by the adopter, if (a) within 6 months of the execution of...

Long-life slab replacement concrete : [summary].

DOT National Transportation Integrated Search

2015-04-01

Concrete slab replacement projects in Florida have demonstrated a high incidence of : replacement slab cracking. Causes of cracking have not been reliably determined. University of South Florida researchers : sought to identify the factors or : param...

Hip or knee replacement - in the hospital after

MedlinePlus

Hip replacement surgery - after - self-care; Knee replacement surgery - after - self-care ... taking walks in the hallways with help. After knee replacement, some surgeons recommend using a continuous passive ...

Cobra Probes Containing Replaceable Thermocouples

NASA Technical Reports Server (NTRS)

Jones, John; Redding, Adam

2007-01-01

A modification of the basic design of cobra probes provides for relatively easy replacement of broken thermocouples. Cobra probes are standard tube-type pressure probes that may also contain thermocouples and that are routinely used in wind tunnels and aeronautical hardware. They are so named because in side views, they resemble a cobra poised to attack. Heretofore, there has been no easy way to replace a broken thermocouple in a cobra probe: instead, it has been necessary to break the probe apart and then rebuild it, typically at a cost between $2,000 and $4,000 (2004 prices). The modified design makes it possible to replace the thermocouple, in minimal time and at relatively low cost, by inserting new thermocouple wire in a tube.

Ross procedure for ascending aortic replacement.

PubMed

Elkins, R C; Lane, M M; McCue, C

1999-06-01

Patients with aortic valve disease and aneurysm or dilatation of the ascending aorta require both aortic valve replacement and treatment of their ascending aortic disease. In children and young adults, the Ross operation is preferred when the aortic valve requires replacement, but the efficacy of extending this operation to include replacement of the ascending aorta or reduction of the dilated aorta has not been tested. We reviewed the medical records of 18 (5.9%) patients with aortic valve disease and an ascending aortic aneurysm and 26 (8.5%) patients with dilation of the ascending aorta, subgroups of 307 patients who had a Ross operation between August 1986 and February 1998. We examined operative and midterm results, including recent echocardiographic assessment of autograft valve function and ability of the autograft root and ascending aortic repair or replacement to maintain normal structural integrity. There was one operative death (2%) related to a perioperative stroke. Forty-two of 43 survivors have normal autograft valve function, with trace to mild autograft valve insufficiency, and one patient has moderate insufficiency at the most recent echocardiographic evaluation. None of the patients has dilatation of the autograft root or of the replaced or reduced ascending aorta. Early results with extension of the Ross operation to include replacement of an ascending aortic aneurysm or vertical aortoplasty for reduction of a dilated ascending aorta are excellent, with autograft valve function equal to that seen in similar patients without ascending aortic disease.

Enhanced operator perception through 3D vision and haptic feedback

NASA Astrophysics Data System (ADS)

Edmondson, Richard; Light, Kenneth; Bodenhamer, Andrew; Bosscher, Paul; Wilkinson, Loren

2012-06-01

Polaris Sensor Technologies (PST) has developed a stereo vision upgrade kit for TALON® robot systems comprised of a replacement gripper camera and a replacement mast zoom camera on the robot, and a replacement display in the Operator Control Unit (OCU). Harris Corporation has developed a haptic manipulation upgrade for TALON® robot systems comprised of a replacement arm and gripper and an OCU that provides haptic (force) feedback. PST and Harris have recently collaborated to integrate the 3D vision system with the haptic manipulation system. In multiple studies done at Fort Leonard Wood, Missouri it has been shown that 3D vision and haptics provide more intuitive perception of complicated scenery and improved robot arm control, allowing for improved mission performance and the potential for reduced time on target. This paper discusses the potential benefits of these enhancements to robotic systems used for the domestic homeland security mission.

Evolution of high tooth replacement rates in sauropod dinosaurs.

PubMed

D'Emic, Michael D; Whitlock, John A; Smith, Kathlyn M; Fisher, Daniel C; Wilson, Jeffrey A

2013-01-01

Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days). Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size), and derived titanosaurs and diplodocoids independently evolved the highest known tooth replacement rates among archosaurs.

Evolution of High Tooth Replacement Rates in Sauropod Dinosaurs

PubMed Central

Smith, Kathlyn M.; Fisher, Daniel C.; Wilson, Jeffrey A.

2013-01-01

Background Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. Methodology/Principal Findings We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days). Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. Conclusions/Significance Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size), and derived titanosaurs and diplodocoids independently

Structural zooming research and development of an interactive computer graphical interface for stress analysis of cracks

NASA Technical Reports Server (NTRS)

Gerstle, Walter

1989-01-01

Engineering problems sometimes involve the numerical solution of boundary value problems over domains containing geometric feature with widely varying scales. Often, a detailed solution is required at one or more of these features. Small details in large structures may have profound effects upon global performance. Conversely, large-scale conditions may effect local performance. Many man-hours and CPU-hours are currently spent in modeling such problems. With the structural zooming technique, it is now possible to design an integrated program which allows the analyst to interactively focus upon a small region of interest, to modify the local geometry, and then to obtain highly accurate responses in that region which reflect both the properties of the overall structure and the local detail. A boundary integral equation analysis program, called BOAST, was recently developed for the stress analysis of cracks. This program can accurately analyze two-dimensional linear elastic fracture mechanics problems with far less computational effort than existing finite element codes. An interactive computer graphical interface to BOAST was written. The graphical interface would have several requirements: it would be menu-driven, with mouse input; all aspects of input would be entered graphically; the results of a BOAST analysis would be displayed pictorially but also the user would be able to probe interactively to get numerical values of displacement and stress at desired locations within the analysis domain; the entire procedure would be integrated into a single, easy to use package; and it would be written using calls to the graphic package called HOOPS. The program is nearing completion. All of the preprocessing features are working satisfactorily and were debugged. The postprocessing features are under development, and rudimentary postprocessing should be available by the end of the summer. The program was developed and run on a VAX workstation, and must be ported to the SUN

The Dram As An X-Ray Sensor

NASA Astrophysics Data System (ADS)

Jacobs, Alan M.; Cox, John D.; Juang, Yi-Shung

1987-01-01

A solid-state digital x-ray detector is described which can replace high resolution film in industrial radiography and has potential for application in some medical imaging. Because of the 10 micron pixel pitch on the sensor, contact magnification radiology is possible and is demonstrated. Methods for frame speed increase and integration of sensor to a large format are discussed.

47 CFR 13.17 - Replacement license.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Replacement license. 13.17 Section 13.17 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL RADIO OPERATORS General § 13.17 Replacement license. (a) Each licensee or permittee whose original document is lost, mutilated, or destroyed must...

SPIDER: Next Generation Chip Scale Imaging Sensor Update

NASA Astrophysics Data System (ADS)

Duncan, A.; Kendrick, R.; Ogden, C.; Wuchenich, D.; Thurman, S.; Su, T.; Lai, W.; Chun, J.; Li, S.; Liu, G.; Yoo, S. J. B.

2016-09-01

The Lockheed Martin Advanced Technology Center (LM ATC) and the University of California at Davis (UC Davis) are developing an electro-optical (EO) imaging sensor called SPIDER (Segmented Planar Imaging Detector for Electro-optical Reconnaissance) that seeks to provide a 10x to 100x size, weight, and power (SWaP) reduction alternative to the traditional bulky optical telescope and focal-plane detector array. The substantial reductions in SWaP would reduce cost and/or provide higher resolution by enabling a larger-aperture imager in a constrained volume. Our SPIDER imager replaces the traditional optical telescope and digital focal plane detector array with a densely packed interferometer array based on emerging photonic integrated circuit (PIC) technologies that samples the object being imaged in the Fourier domain (i.e., spatial frequency domain), and then reconstructs an image. Our approach replaces the large optics and structures required by a conventional telescope with PICs that are accommodated by standard lithographic fabrication techniques (e.g., complementary metal-oxide-semiconductor (CMOS) fabrication). The standard EO payload integration and test process that involves precision alignment and test of optical components to form a diffraction limited telescope is, therefore, replaced by in-process integration and test as part of the PIC fabrication, which substantially reduces associated schedule and cost. This paper provides an overview of performance data on the second-generation PIC for SPIDER developed under the Defense Advanced Research Projects Agency (DARPA)'s SPIDER Zoom research funding. We also update the design description of the SPIDER Zoom imaging sensor and the second-generation PIC (high- and low resolution versions).

Examining in vivo tympanic membrane mobility using smart phone video-otoscopy and phase-based Eulerian video magnification

NASA Astrophysics Data System (ADS)

Janatka, Mirek; Ramdoo, Krishan S.; Tatla, Taran; Pachtrachai, Krittin; Elson, Daniel S.; Stoyanov, Danail

2017-03-01

The tympanic membrane (TM) is the bridging element between the pressure waves of sound in air and the ossicular chain. It allows for sound to be conducted into the inner ear, achieving the human sense of hearing. Otitis media with effusion (OME, commonly referred to as `glue ear') is a typical condition in infants that prevents the vibration of the TM and causes conductive hearing loss, this can lead to stunting early stage development if undiagnosed. Furthermore, OME is hard to identify in this age group; as they cannot respond to typical audiometry tests. Tympanometry allows for the mobility of the TM to be examined without patient response, but requires expensive apparatus and specialist training. By combining a smartphone equipped with a 240 frames per second video recording capability with an otoscopic clip-on accessory, this paper presents a novel application of Eulerian Video Magnification (EVM) to video-otology, that could provide assistance in diagnosing OME. We present preliminary results showing a spatio-temporal slice taken from an exaggerated video visualization of the TM being excited in vivo on a healthy ear. Our preliminary results demonstrate the potential for using such an approach for diagnosing OME under visual inspection as alternative to tympanometry, which could be used remotely and hence help diagnosis in a wider population pool.

[Longterm results of mitral valve replacement (author's transl)].

PubMed

Erhard, W; Reichmann, M; Delius, W; Sebening, H; Herrmann, G

1977-04-22

210 patients were followed up by the actuary method for over 5 years after isolated mitral valve replacement or a double valve replacement. After isolated valve replacement the one month survival including the operative mortality was 92+/-2%. The survival after one year was 83+/-3% and after 5 years 66+/-7%. The five year survival of patients in preoperative class III (according to the NYHA) was 73+/-8% and of class IV 57+/-8% (P less than or equal to 0.1). A comparison of valve replacements for pure mitral stenosis or mitral insufficiency showed no statistically significant differences. In the 37 patients who had a double valve replacement the survival risk was not increased in comparison with those patients who had had a single valve replacement. Age above 45 years and a preoperative markedly raised pulmonary arteriolar resistance reduced the chances of survival.

Urban chaos and replacement dynamics in nature and society

NASA Astrophysics Data System (ADS)

Chen, Yanguang

2014-11-01

Replacements resulting from competition are ubiquitous phenomena in both nature and society. The evolution of a self-organized system is always a physical process substituting one type of components for another type of components. A logistic model of replacement dynamics has been proposed in terms of technical innovation and urbanization, but it fails to arouse widespread attention in the academia. This paper is devoted to laying the foundations of general replacement principle by using analogy and induction. The empirical base of this study is urban replacement, including urbanization and urban growth. The sigmoid functions can be employed to model various processes of replacement. Many mathematical methods such as allometric scaling and head/tail breaks can be applied to analyzing the processes and patterns of replacement. Among varied sigmoid functions, the logistic function is the basic and the simplest model of replacement dynamics. A new finding is that replacement can be associated with chaos in a nonlinear system, e.g., urban chaos is just a part of replacement dynamics. The aim of developing replacement theory is at understanding complex interaction and conversion. This theory provides a new way of looking at urbanization, technological innovation and diffusion, Volterra-Lotka’s predator-prey interaction, man-land relation, and dynastic changes resulting from peasant uprising, and all that. Especially, the periodic oscillations and chaos of replacement dynamics can be used to explain and predict the catastrophic occurrences in the physical and human systems.

25 CFR 700.187 - Utilization of replacement home benefits.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 25 Indians 2 2012-04-01 2012-04-01 false Utilization of replacement home benefits. 700.187 Section... PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The Commission... to the head of household as provided in these regulations for the acquisition of a replacement home...

25 CFR 700.187 - Utilization of replacement home benefits.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 25 Indians 2 2013-04-01 2013-04-01 false Utilization of replacement home benefits. 700.187 Section... PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The Commission... to the head of household as provided in these regulations for the acquisition of a replacement home...

25 CFR 700.187 - Utilization of replacement home benefits.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 25 Indians 2 2011-04-01 2011-04-01 false Utilization of replacement home benefits. 700.187 Section... PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The Commission... to the head of household as provided in these regulations for the acquisition of a replacement home...

25 CFR 700.187 - Utilization of replacement home benefits.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 2 2010-04-01 2010-04-01 false Utilization of replacement home benefits. 700.187 Section... PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The Commission... to the head of household as provided in these regulations for the acquisition of a replacement home...

25 CFR 700.187 - Utilization of replacement home benefits.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 25 Indians 2 2014-04-01 2014-04-01 false Utilization of replacement home benefits. 700.187 Section... PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The Commission... to the head of household as provided in these regulations for the acquisition of a replacement home...

H-ATLAS/GAMA: magnification bias tomography. Astrophysical constraints above ∼1 arcmin

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

González-Nuevo, J.; Bonavera, L.; Lapi, A.

An unambiguous manifestation of the magnification bias is the cross-correlation between two source samples with non-overlapping redshift distributions. In this work we measure and study the cross-correlation signal between a foreground sample of GAMA galaxies with spectroscopic redshifts in the range 0.2< z <0.8, and a background sample of H-ATLAS galaxies with photometric redshifts ∼>1.2. It constitutes a substantial improvement over the cross-correlation measurements made by Gonzalez-Nuevo et al. (2014) with updated catalogues and wider area (with S / N ∼> 5 below 10 arcmin and reaching S / N ∼ 20 below 30 arcsec). The better statistics allow usmore » to split the sample in different redshift bins and to perform a tomographic analysis (with S / N ∼> 3 below 10 arcmin and reaching S / N ∼ 15 below 30 arcsec). Moreover, we implement a halo model to extract astrophysical information about the background galaxies and the deflectors that are producing the lensing link between the foreground (lenses) and background (sources) samples. In the case of the sources, we find typical mass values in agreement with previous studies: a minimum halo mass to host a central galaxy, M {sub min}∼ 10{sup 12.26} M {sub ⊙}, and a pivot halo mass to have at least one sub-halo satellite, M {sub 1∼} 10{sup 12.84} M {sub ⊙}. However, the lenses are massive galaxies or even galaxy groups/clusters, with minimum mass of M {sub min}{sup lens}∼ 10{sup 13.06} M {sub ⊙}. Above a mass of M {sub 1}{sup lens}∼ 10{sup 14.57} M {sub ⊙} they contain at least one additional satellite galaxy which contributes to the lensing effect. The tomographic analysis shows that, while M {sub 1}{sup lens} is almost redshift independent, there is a clear evolution of increase M {sub min}{sup lens} with redshift in agreement with theoretical estimations. Finally, the halo modeling allows us to identify a strong lensing contribution to the cross-correlation for angular scales below 30 arcsec

ReplacementMatrix: a web server for maximum-likelihood estimation of amino acid replacement rate matrices.

PubMed

Dang, Cuong Cao; Lefort, Vincent; Le, Vinh Sy; Le, Quang Si; Gascuel, Olivier

2011-10-01

Amino acid replacement rate matrices are an essential basis of protein studies (e.g. in phylogenetics and alignment). A number of general purpose matrices have been proposed (e.g. JTT, WAG, LG) since the seminal work of Margaret Dayhoff and co-workers. However, it has been shown that matrices specific to certain protein groups (e.g. mitochondrial) or life domains (e.g. viruses) differ significantly from general average matrices, and thus perform better when applied to the data to which they are dedicated. This Web server implements the maximum-likelihood estimation procedure that was used to estimate LG, and provides a number of tools and facilities. Users upload a set of multiple protein alignments from their domain of interest and receive the resulting matrix by email, along with statistics and comparisons with other matrices. A non-parametric bootstrap is performed optionally to assess the variability of replacement rate estimates. Maximum-likelihood trees, inferred using the estimated rate matrix, are also computed optionally for each input alignment. Finely tuned procedures and up-to-date ML software (PhyML 3.0, XRATE) are combined to perform all these heavy calculations on our clusters. http://www.atgc-montpellier.fr/ReplacementMatrix/ olivier.gascuel@lirmm.fr Supplementary data are available at http://www.atgc-montpellier.fr/ReplacementMatrix/

The value of genetic information in selecting dairy replacements.

PubMed

Radke, Brian R; Lloyd, James W; Black, J Roy; Harsh, Stephen

2005-09-30

The objective of this study was to empirically determine the economic value of genetic information in the selection of dairy replacements, and assess whether this value was sufficient to prompt producers to select replacements on this basis. The data set consisted of 1982 Michigan Holstein replacements in 115 herds. Each herd had a minimum of 10 replacements that were born in the last 6 months of 1992 and calved within the last 6 months of 1994. The data for each replacement included the estimated breeding value (EBV) for milk at the beginning and end of the rearing period, and the estimated lifetime profit corrected for the opportunity cost of postponed replacement (ELPCOC). The replacement selection decision for a profit-maximizing dairy producer selecting 70 or 80% of the replacements was modeled. We modeled three methods of selection: genetic, random and ex poste. Genetic selection was evaluated using the EBV milk available at the beginning or end of the rearing period. For each herd, the profit associated with each of the three methods of selection was simulated. The value of the genetic information and perfect information were the differences in herd profits of genetic selection and ex poste selection relative to random selection, respectively. The difference in value of the genetic information between the end of the rearing period and the beginning of the rearing period was the increase in value of the genetic information due to updating. The value of information was calculated as the average herd profit per replacement. The value of the genetic information ranged from 22 dollars/replacement to 30 dollars/replacement and was statistically greater than zero at a 95% confidence level. It is unclear whether this value is sufficient to prompt producers to select replacements on the basis of EBV milk as has been recommended. The negative value of EBV milk (from the end of the rearing period when selecting 80% of the replacements) for 32 herds was consistent with

Knee joint replacement

MedlinePlus

... Knee joint replacement - series References American Academy of Orthopedic Surgeons (AAOS) website. Treatment of osteoarthritis of the knee: evidence-based guideline 2nd edition (summary) . www.aaos.org/research/guidelines/TreatmentofOsteoarthritisoftheKneeGuideline.pdf . Updated May 18, 2013. Accessed ...

30 CFR 823.14 - Soil replacement.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Soil replacement. 823.14 Section 823.14 Mineral... Soil replacement. (a) Soil reconstruction specifications established by the U.S. Soil Conservation Service shall be based upon the standards of the National Cooperative Soil Survey and shall include, as a...

30 CFR 823.14 - Soil replacement.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Soil replacement. 823.14 Section 823.14 Mineral... Soil replacement. (a) Soil reconstruction specifications established by the U.S. Soil Conservation Service shall be based upon the standards of the National Cooperative Soil Survey and shall include, as a...

30 CFR 823.14 - Soil replacement.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Soil replacement. 823.14 Section 823.14 Mineral... Soil replacement. (a) Soil reconstruction specifications established by the U.S. Soil Conservation Service shall be based upon the standards of the National Cooperative Soil Survey and shall include, as a...

30 CFR 823.14 - Soil replacement.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Soil replacement. 823.14 Section 823.14 Mineral... Soil replacement. (a) Soil reconstruction specifications established by the U.S. Soil Conservation Service shall be based upon the standards of the National Cooperative Soil Survey and shall include, as a...

30 CFR 823.14 - Soil replacement.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Soil replacement. 823.14 Section 823.14 Mineral... Soil replacement. (a) Soil reconstruction specifications established by the U.S. Soil Conservation Service shall be based upon the standards of the National Cooperative Soil Survey and shall include, as a...

Mercury Thermometer Replacements in Chemistry Laboratories

ERIC Educational Resources Information Center

Foster, Barbara L.

2005-01-01

The consequences of broken mercury-in-glass thermometers in academic laboratories results in various health and environmental hazards, which needs to be replaced, by long-stem digital thermometers and non-mercury glass thermometers. The factors that should be considered during the mercury replacement process are types of applications in the…

24 CFR 891.855 - Replacement reserves.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Partnerships and Mixed-Finance Development for Supportive Housing for the Elderly or Persons with Disabilities § 891.855 Replacement reserves. (a) The mixed-finance owner shall establish and maintain a replacement... requirements of 24 CFR 891.405. (b) The mixed-finance owner may obtain a disbursement from the reserve only if...

[Vitrectomy: in search of the ideal vitreous replacement].

PubMed

Steijns, Daan; Stilma, Jan S

2009-01-01

Pars plana vitrectomy is a form of surgery to remove the vitreous body. It is performed with various eye diseases. Replacement of the vitreous body is necessitated by its removal. After more than 50 years the search for the ideal vitreous replacement has not yet ended. Different materials are used to replace the vitreous body. The advantages, disadvantages and applications of those materials are discussed. The lack of a material to successfully replace the vitreous body is a significant restriction in the treatment vitreoretinal pathologies.

[Clinical study on patellar replacement in total knee arthroplasty].

PubMed

Bao, Liang; Gao, Zhihui; Shi, Xiaoqiang; Fang, Xiaomin; Jin, Qunhua

2013-01-01

To evaluate the influence of patellar replacement on total knee arthroplasty by comparing with non patellar replacement. Between September 2010 and November 2010, 63 patients (63 knees) with osteoarthritis who met the selection criteria and underwent total knee arthroplasty, were randomly divided into 2 groups: patellar replacement in 32 cases (replacement group), non patellar replacement in 31 cases (non patellar replacement group). There was no significant difference in gender, age, disease duration, osteoarthritis grading, the clinical and functional scores of American Knee Society Score (KSS), the patellar tilt angle, tibiofemoral angle, and patellar ligament ratio between 2 groups (P > 0.05), they were comparable. After 6 weeks, 3, 6, and 12 months of operation, clinical and imaging evaluation methods were used to assessment the effectiveness. Primary healing of incision was obtained in all patients of 2 groups. Deep venous thrombosis occurred in 6 cases of replacement group and in 8 cases of non patellar replacement group. All patients were followed up 12 months. The postoperative incidence of anterior knee pain in replacement group was significantly lower than that in non patellar replacement group (P < 0.05) at 3, 6, and 12 months after operation. No significant difference was found in the postoperative KSS clinical score between 2 groups at each time point (P > 0.05). The joint function score of the replacement group was significantly higher than that of the non patellar replacement group at the other time point (P < 0.05) except the score at 6 weeks and 3 months. Significant difference was found in the patella score between 2 groups at 12 months (P < 0.05), but no significant difference at the other time points (P > 0.05). X-ray film showed no patellar fracture and dislocation, or loosening and breakage of internal fixation. At 12 months after operation, the tibiofemoral angle, the patellar ligament ratio, and the patellar tilt angle showed no significant

14 CFR 21.9 - Replacement and modification articles.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

14 CFR 21.9 - Replacement and modification articles.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

14 CFR 21.9 - Replacement and modification articles.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

14 CFR 21.9 - Replacement and modification articles.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

14 CFR 21.9 - Replacement and modification articles.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

Managing the replacement cycle of laser inventory.

PubMed

Davis, C E

1992-01-01

Medical lasers are quickly moving into the replacement phase of technology management. Barnes Hospital (St. Louis, MO) is using its laser team to define a process of planned laser replacement using the experience gained from traditional medical equipment replacement cycles, quality improvement principles and tools, and other formalized interdisciplinary teams. The process described in this paper has six basic steps: (1) A decision is made to request a replacement laser. (2) An appropriation request form is completed and submitted with the clinical and/or technical justifications. (3) Those requests initiated outside of the Clinical Engineering Department are reviewed by the Clinical Engineer/Medical Laser Safety Officer (CE/MLSO). (4) The CE/MLSO presents the requests to the hospital Laser Committee, and (5) then to the Laser Users' Group. (6) Finally, an Expenditure Authorization Committee reviews all capital expense requests, including those for replacement lasers, and allocates funds for the next fiscal year. This paper illustrates and evaluates the process, using an example from the review process for 1993 equipment purchases at Barnes Hospital.

Mercury Speciation and Trophic Magnification Slopes in Giant Salamander Larvae from the Pacific Northwest, USA

NASA Astrophysics Data System (ADS)

Bank, M. S.; Crocker, J.; Wachtl, J.; Kleeman, P.; Fellers, G.; Currens, C.; Hothem, R.; Madej, M. A.

2014-12-01

Mercury (Hg) contamination of stream salamanders in the Pacific Northwest region of the United States has received little attention. Here we report total Hg (HgT) and methyl mercury (MeHg) concentrations in larval giant salamanders (Dicamptodon spp.) and surface water from forested and chaparral lotic ecosystems distributed along a latitudinal gradient throughout Northern California and Washington. To test hypotheses related to potential effects from mining land-use activities, salamander larvae were also sampled from a reference site at Whiskeytown National Recreation Area, California, and at a nearby, upstream site (Shasta county) on Bureau of Land Management land where Hg contamination from gold mining activities has been documented. HgT concentrations in whole body larvae ranged from 4.6 to 74.5 ng/g wet wt. and percent MeHg ranged from 67% to 86%. Both HgT and MeHg larval tissue concentrations were significantly higher at the mining site in comparison to measured background levels (P < 0.001). We conclude that salamander larvae in remote stream ecosystems, where Hg sources were dominated by atmospheric deposition, were generally low in HgT and MeHg and, in comparison, watersheds with a legacy of land-use practices (i.e., mining operations) had approximately 4.5 - 5.5 times the level of HgT bioaccumulation. Moreover, trophic magnification slopes were highest in the Shasta county region where mining was present. These findings suggest that mining activities increase HgT and MeHg exposure to salamander larvae in the region and may present a threat to other higher trophically positioned organisms, and their associated food webs.

Prioritization Methodology for Chemical Replacement

NASA Technical Reports Server (NTRS)

Cruit, W.; Schutzenhofer, S.; Goldberg, B.; Everhart, K.

1993-01-01

This project serves to define an appropriate methodology for effective prioritization of efforts required to develop replacement technologies mandated by imposed and forecast legislation. The methodology used is a semiquantitative approach derived from quality function deployment techniques (QFD Matrix). This methodology aims to weigh the full environmental, cost, safety, reliability, and programmatic implications of replacement technology development to allow appropriate identification of viable candidates and programmatic alternatives. The results are being implemented as a guideline for consideration for current NASA propulsion systems.

9 CFR 82.15 - Replacement birds and poultry.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Replacement birds and poultry. 82.15...- EASE (END) AND CHLAMYDIOSIS Exotic Newcastle Disease (END) § 82.15 Replacement birds and poultry. Birds and poultry that have been destroyed because of a quarantine for END may not be replaced by birds or...

9 CFR 82.15 - Replacement birds and poultry.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Replacement birds and poultry. 82.15...- EASE (END) AND CHLAMYDIOSIS Exotic Newcastle Disease (END) § 82.15 Replacement birds and poultry. Birds and poultry that have been destroyed because of a quarantine for END may not be replaced by birds or...

Fleet replacement modeling : final report, July 2009.

DOT National Transportation Integrated Search

2009-07-01

This project focused on two interrelated areas in equipment replacement modeling for fleets. The first area was research-oriented and addressed a fundamental assumption in engineering economic replacement modeling that all assets providing a similar ...

42 CFR 433.117 - Initial approval of replacement systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... and Information Retrieval Systems § 433.117 Initial approval of replacement systems. (a) A replacement... information retrieval system. (b) The agency must submit a APD that includes— (1) The date the replacement...

42 CFR 433.117 - Initial approval of replacement systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... and Information Retrieval Systems § 433.117 Initial approval of replacement systems. (a) A replacement... information retrieval system. (b) The agency must submit a APD that includes— (1) The date the replacement...

42 CFR 433.117 - Initial approval of replacement systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... and Information Retrieval Systems § 433.117 Initial approval of replacement systems. (a) A replacement... information retrieval system. (b) The agency must submit a APD that includes— (1) The date the replacement...

42 CFR 433.117 - Initial approval of replacement systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... and Information Retrieval Systems § 433.117 Initial approval of replacement systems. (a) A replacement... information retrieval system. (b) The agency must submit a APD that includes— (1) The date the replacement...

Mitochondrial replacement techniques: egg donation, genealogy and eugenics.

PubMed

Palacios-González, César

2016-03-01

Several objections against the morality of researching or employing mitochondrial replacement techniques have been advanced recently. In this paper, I examine three of these objections and show that they are found wanting. First I examine whether mitochondrial replacement techniques, research and clinical practice, should not be carried out because of possible harms to egg donors. Next I assess whether mitochondrial replacement techniques should be banned because they could affect the study of genealogical ancestry. Finally, I examine the claim that mitochondrial replacement techniques are not transferring mitochondrial DNA but nuclear DNA, and that this should be prohibited on ethical grounds.

Prioritization methodology for chemical replacement

NASA Technical Reports Server (NTRS)

Goldberg, Ben; Cruit, Wendy; Schutzenhofer, Scott

1995-01-01

This methodology serves to define a system for effective prioritization of efforts required to develop replacement technologies mandated by imposed and forecast legislation. The methodology used is a semi quantitative approach derived from quality function deployment techniques (QFD Matrix). QFD is a conceptual map that provides a method of transforming customer wants and needs into quantitative engineering terms. This methodology aims to weight the full environmental, cost, safety, reliability, and programmatic implications of replacement technology development to allow appropriate identification of viable candidates and programmatic alternatives.

Cadmium plating replacements

NASA Technical Reports Server (NTRS)

Nelson, Mary J.; Groshart, Earl C.

1995-01-01

The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

Hormone replacement therapy and risk of malignancy.

PubMed

Diamanti-Kandarakis, Evanthia

2004-02-01

The fact that today our concern is oriented towards the risks rather than the benefits of hormone replacement therapy could be the clearest message about our current position. The safety of hormone replacement therapy, an estrogen-progestin combination which has been sympathetic to and supportive of disturbing menopausal symptoms of women, is seriously challenged. Four randomized trials have now reported on the results of hormone replacement therapy in major potentially fatal conditions, in more than 20,000 women studied for about 5 years. The main concern regarding the increased risk of malignancy in healthy postmenopausal women in western countries has been breast cancer. It is estimated to cause an extra case in about six per 1000 users aged 50-59 and 12 per 1000 aged 60-69. Over the same period the estimated risk of endometrial cancer rates are not increased, with a relative risk of 0.76 per 1000 users aged 50-59. Overall, however, the increased incidence of malignancies is greater than any reduction, one per 230 users aged 50-59 and one per 150 aged 60-69. Randomized trials examining other important but rarer malignancies, like ovarian, gall bladder and urinary bladder cancer, are either nonexistent or too small to reliably describe any effects of hormone replacement therapy. Conclusively epidemiological evidence suggests that hormone replacement therapy is associated with a small but substantial increase in breast cancer risk and combined estrogen-progesterone regimens further increase this hazard. Additionally, the evidence from the recent double blind placebo controlled randomized trial on the slight increase in the incidence of adverse cardiovascular events, has turned our orientation away from hormone replacement therapy as a long term therapy in postmenopausal women. In this review, the effort is to approach comprehensively and globally the information on the risks of hormone replacement therapy on several cancer sites.

Frequency and impact of informant replacement in Alzheimer disease research.

PubMed

Grill, Joshua D; Zhou, Yan; Karlawish, Jason; Elashoff, David

2015-01-01

Informants serve an essential role in Alzheimer disease research. Were an informant to be replaced during a longitudinal study, this could have negative implications. We used data from the National Alzheimer's Coordinating Center Uniform Data Set to examine the frequency of informant replacement among Alzheimer disease dementia participants, whether patient and informant characteristics were associated with replacement, and how replacement affected research outcome measures. Informant replacement was common (15.5%) and typically occurred after the first or the second research visit. Adult child (24%) and other (38%) informants were more frequently replaced than spouse informants (10%). Older spouse informant age and younger adult child informant age were associated with replacement. The between-visit change in Functional Assessment Questionnaire scores was greater in patients who replaced informants than in those with stable informants. Clinical Dementia Rating-Sum of Boxes, Functional Assessment Questionnaire, and Neuropsychiatric Inventory scores showed greater variability in between-visit change in patients who replaced informants compared with those with stable informants. These findings suggest that informant replacement is relatively common, may have implications to study analyses, and warrant further examination in the setting of clinical trials.

Improvement in Visual Target Tracking for a Mobile Robot

NASA Technical Reports Server (NTRS)

Kim, Won; Ansar, Adnan; Madison, Richard

2006-01-01

In an improvement of the visual-target-tracking software used aboard a mobile robot (rover) of the type used to explore the Martian surface, an affine-matching algorithm has been replaced by a combination of a normalized- cross-correlation (NCC) algorithm and a template-image-magnification algorithm. Although neither NCC nor template-image magnification is new, the use of both of them to increase the degree of reliability with which features can be matched is new. In operation, a template image of a target is obtained from a previous rover position, then the magnification of the template image is based on the estimated change in the target distance from the previous rover position to the current rover position (see figure). For this purpose, the target distance at the previous rover position is determined by stereoscopy, while the target distance at the current rover position is calculated from an estimate of the current pose of the rover. The template image is then magnified by an amount corresponding to the estimated target distance to obtain a best template image to match with the image acquired at the current rover position.

Replacement solvents for use in chemical synthesis

DOEpatents

Molnar, Linda K.; Hatton, T. Alan; Buchwald, Stephen L.

2001-05-15

Replacement solvents for use in chemical synthesis include polymer-immobilized solvents having a flexible polymer backbone and a plurality of pendant groups attached onto the polymer backbone, the pendant groups comprising a flexible linking unit bound to the polymer backbone and to a terminal solvating moiety. The polymer-immobilized solvent may be dissolved in a benign medium. Replacement solvents for chemical reactions for which tetrahydrofuran or diethyl may be a solvent include substituted tetrahydrofurfuryl ethers and substituted tetrahydro-3-furan ethers. The replacement solvents may be readily recovered from the reaction train using conventional methods.

Introduction to the development of intraocular lens

NASA Astrophysics Data System (ADS)

Li, Yifan; Peng, Runling; Hu, Shuilan; Wei, Maowei; Chen, Jiabi

2013-08-01

In order to cure the cataract disease or injuries in eyes, intraocular lens(IOL) has been studied all the time to replace the crystalline lens in human eyes. Researches on IOL are started early from 19th century, and it develops greatly in the hundreds years after. This article introduces several main kinds of IOLs that appear in the development history of IOL, and raises the double-liquid zoom IOL based on electrowetting, which will be the trend of IOL study.

Bottom ash as aggregate replacement in concrete.

DOT National Transportation Integrated Search

2013-06-01

The objective of the proposed study is to evaluate bottom ash as a partial or total replacement of the fine and coarse aggregate in : concrete. This program will characterize and evaluate available bottom ash sources as potential replacement of both ...

Total ankle replacement systems available in the United States.

PubMed

Coetzee, J Chris; Deorio, James K

2010-01-01

Ankle replacement continues to be a viable option for treating patients with ankle arthritis. Over the past 10 years, there has been a significant increase in the number of ankle replacement systems available for use. Current controversy centers on whether fixed- or mobile-bearing devices are most advantageous. Most total ankle systems used outside the United States are mobile-bearing devices, whereas ankle replacement systems used in the United States are all essentially fixed-bearing devices. Not all ankles with degenerative changes are amenable to replacement surgery, and several exclusion criteria are well documented. Ankle replacement is especially complicated because of the ankle's proximity to the foot and the important role that the balance and alignment of the foot play in the success of the ankle replacement. Foot deformities should be treated before or at the time of ankle replacement surgery. Ignoring foot deformities can lead to failure of the ankle replacement. It is also of paramount importance to consider the stability of the ankle ligaments. An unstable ankle with a varus or valgus deformity of more than 20 degrees is probably not amenable to ankle replacement. There are currently no reliable options to predictably reconstruct the lateral or medial ligaments in these severe deformities. It is important to be aware of the ankle replacement systems currently available in the United States and understand the key features of each design. Devices approved by the US Food and Drug Administration, a device that is awaiting approval, and a device that is being evaluated by the Food and Drug Administration in a prospective randomized clinical trial are discussed, along with an objective comparison of fixed- and mobile-bearing devices.

HST Replacement Battery Initial Performance

NASA Technical Reports Server (NTRS)

Krol, Stan; Waldo, Greg; Hollandsworth, Roger

2009-01-01

The Hubble Space Telescope (HST) original Nickel-Hydrogen (NiH2) batteries were replaced during the Servicing Mission 4 (SM4) after 19 years and one month on orbit.The purpose of this presentation is to highlight the findings from the assessment of the initial sm4 replacement battery performance. The batteries are described, the 0 C capacity is reviewed, descriptions, charts and tables reviewing the State Of Charge (SOC) Performance, the Battery Voltage Performance, the battery impedance, the minimum voltage performance, the thermal performance, the battery current, and the battery system recharge ratio,

Precast concrete replacement slabs for bridge decks.

DOT National Transportation Integrated Search

1982-01-01

The report illustrates and evaluates the first use in Virginia of precast concrete replacement slabs for bridge decks. It shows that a bridge deck can be replaced with the precast slabs while traffic is maintained in the adjacent traffic lane. The qu...

Implementation of a timed, electronic, assessment-driven potassium-replacement protocol.

PubMed

Zielenski, Christopher; Crabtree, Adam; Le, Tien; Marlatt, Alyse; Ng, Dana; Tran, Alan

2017-06-15

The adherence to and effectiveness and safety of a timed, electronic, assessment-driven potassium-replacement protocol (TARP) were compared with an electronic nurse-driven replacement protocol (NRP) are reported. A retrospective observational study was conducted in a community hospital evaluating protocol adherence, effectiveness, and safety for 2 potassium-replacement protocols. All adults on medical units with an order for potassium replacement per protocol during the 3-month trial periods were reviewed. All patients requiring potassium replacement per protocol were included in the analysis. Adherence to the protocol was assessed by evaluating the dose of potassium administered and performance of reassessments. Effectiveness of the protocol was assessed by evaluating the time to achieve target potassium levels. Safety was assessed by evaluating the route of administration and occurrence of hyperkalemia. A total of 300 patients treated using potassium-replacement protocols required potassium replacement during the study period, with 148 patients in the NRP group requiring 491 instances of potassium replacement. In the TARP group a total of 564 instances requiring potassium replacement corresponded to 152 patients. Of the 491 instances requiring replacement in the NRP group, the correct dose was administered and reassessment performed 117 times (23.8%). Overall adherence ( p < 0.05), correct dose given ( p < 0.05), average time from blood draw to potassium replacement ( p < 0.0001), use of oral replacement ( p < 0.05), and time to achieve target potassium level within 12 hours ( p < 0.05) were significantly improved in the TARP group. The TARP improved the effectiveness and safety of potassium-replacement therapy over the traditional NRP without negatively affecting timeliness of care. Copyright © 2017 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

Differences in the stress distribution in the distal femur between patellofemoral joint replacement and total knee replacement: a finite element study

PubMed Central

2012-01-01

Background Patellofemoral joint replacement is a successful treatment option for isolated patellofemoral osteoarthritis. However, results of later conversion to total knee replacement may be compromised by periprosthetic bone loss. Previous clinical studies have demonstrated a decrease in distal femoral bone mineral density after patellofemoral joint replacement. It is unclear whether this is due to periprosthetic stress shielding. The main objective of the current study was to evaluate the stress shielding effect of prosthetic replacement with 2 different patellofemoral prosthetic designs and with a total knee prosthesis. Methods We developed a finite element model of an intact patellofemoral joint, and finite element models of patellofemoral joint replacement with a Journey PFJ prosthesis, a Richards II prosthesis, and a Genesis II total knee prosthesis. For each of these 4 finite element models, the average Von Mises stress in 2 clinically relevant regions of interest were evaluated during a simulated squatting movement until 120 degrees of flexion. Results During deep knee flexion, in the anterior region of interest, the average Von Mises stress with the Journey PFJ design was comparable to the physiological knee, while reduced by almost 25% for both the Richards II design and the Genesis II total knee joint replacement design. The average Von Mises stress in the supracondylar region of interest was similar for both patellofemoral prosthetic designs and the physiological model, with slightly lower stress for the Genesis II design. Conclusions Patellofemoral joint replacement results in periprosthetic stress-shielding, although to a smaller degree than in total knee replacement. Specific patellofemoral prosthetic design properties may result in differences in femoral stress shielding. PMID:22704638

Applying stand replacement prescribed fires in Alaska

Treesearch

Larry A. Vanderlinden

1996-01-01

Stand replacement prescribed burning has been applied in Alaska on several occasions. Based on that experience, perspectives can be provided, issues can be discussed, and keys to success can be identified that are applicable to stand replacement prescribed burning activities in areas outside Alaska.

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.

Kinetic studies of halon replacements.

NASA Astrophysics Data System (ADS)

Orkin, Vladimir L.

2013-04-01

Despite their excellence as fire suppressants, the production of halons (bromofluorocarbons) is being phased out because of the danger they pose to the Earth's stratospheric ozone layer. A number of bromine free substances have been proposed and tested, but the effort to find replacements continues to return to bromine-containing compounds because of the properties of bromine as a chemically active flame suppressant. The primary approach to this problem has been to test candidate replacement compounds that have short atmospheric lifetimes or/and lack bromine, the halogen atoms that catalyze ozone destruction. Various chemical classes (alkanes, ethers, alkenes) have been studied both earlier and recently. The reaction with atmospheric hydroxyl radicals dictates the residence time and accumulation in the atmosphere of all potential halon replacements. Therefore, we improved a flash photolysis - resonance fluorescence apparatus to provide the most accurate OH reaction rate constants measured over the atmospheric temperatures. Supplementary UV absorption spectra were measured to allow the estimation of ODPs. Although a thorough 3-D modeling is required to assess ODPs, the simplified estimations can be made based on the compounds lifetimes.

[Local infiltration analgesia in total joint replacement].

PubMed

de Jonge, Tamás; Görgényi, Szabolcs; Szabó, Gabriella; Torkos, Miklós Bulcsú

2017-03-01

Total hip and knee replacment surgeries are characterized by severe postoperative pain. Local infiltration analgesia is proved to be very effective. However this method has not been widely used in Hungary. To evaluate the efficacy of the local infiltration analgesia with modified components in patients underwent total hip or knee replacement surgery. Data of 99 consecutive patients underwent primary total hip or knee replacement surgery were evaluated prospectively. In all the 99 surgeries modified local infiltration analgesia was applied. Postoperative pain reported on a visual analog scale was recorded as well as the need for further analgetics during the first 18 hours after surgery. The cost of the analgetic drugs was calculated. The control group comprised 97 consecutive patients underwent total hip or knee replacement, where local infiltration analgesia was not applied. Statistical analysis was done. Patients received local infiltration analgesia reported significantly less pain (p<0.001). The need for postoperatively given analgetics was almost 50% less, and the cost of all postoperative analgetics was 47% less than in the control group. In total hip and knee replacement surgeries the modified local infiltration analgesia decreases postoperative pain effectively and contribute to the early mobilization of the patients. Orv. Hetil., 2017, 158(9), 352-357.

21 CFR 870.3710 - Pacemaker repair or replacement material.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is an...

21 CFR 870.3710 - Pacemaker repair or replacement material.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is an...

21 CFR 870.3710 - Pacemaker repair or replacement material.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is an...

21 CFR 870.3710 - Pacemaker repair or replacement material.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is an...

R-process Enrichment in Cosmological Zoom Simulation of a Milkyway Type Halo by Neutron Star Mergers; The Origin of the MP-R and CEMP-R Stars

NASA Astrophysics Data System (ADS)

Safarzadeh, Mohammadtaher; Scannapieco, Evan

2018-06-01

The history of r-process enrichment in our galaxy is modeled through a novel set of zoom cosmo- logical simulations on a MilkyWay type galaxy. r-process sources are assumed to be neutron star mergers with a distribution of natal kicks and merge time distribution. We model turbulent mixing to estimate the pristine gas fraction in each simulation cell which we use to determine the Pop III star formation with assigned Carbon rich ejecta when going off as SNe. We follow the formation of Carbon-Enhanced Metal-Poor (CEMP) stars and the statistics of different r-process enhanced class of stars. The simulation underpredict the frequency of CEMP/MP stars by a factor of 2-4. Likewise the MP-rI/MP and MP-rII/MP and CEMP-r/CEMP cumulative ratios are all under predicted by 1-2 orders of magnitude. Our results show that NS binaries by themselves fall too short to explain the observed frequency of r-process enhanced stars and other sources of r-process enrichment at high redshifts are needed to fill the gap.

38 CFR 21.220 - Replacement of supplies.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Vocational Rehabilitation and Employment Under 38 U.S.C... will replace articles which are necessary to further pursuit of the veteran's program and which are... advancement from the Vocational Rehabilitation Revolving Fund to a veteran to replace articles for which VA...

30 CFR 872.29 - What are prior balance replacement funds?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false What are prior balance replacement funds? 872... § 872.29 What are prior balance replacement funds? “Prior balance replacement funds” are moneys we must... SMCRA, we distribute prior balance replacement funds to you, the State or Indian tribe, for seven years...

30 CFR 872.29 - What are prior balance replacement funds?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false What are prior balance replacement funds? 872... § 872.29 What are prior balance replacement funds? “Prior balance replacement funds” are moneys we must... SMCRA, we distribute prior balance replacement funds to you, the State or Indian tribe, for seven years...

Hip joint replacement - slideshow

MedlinePlus

... this page: //medlineplus.gov/ency/presentations/100006.htm Hip joint replacement - series—Normal anatomy To use the ... to slide 5 out of 5 Overview The hip joint is made up of two major parts: ...

Valve Repair or Replacement

MedlinePlus

... called anticoagulants) for the rest of their lives. Biological valves are made from animal tissue (called a ... for valve replacement (called an autograft). Patients with biological valves usually do not need to take blood- ...

ARRANGEMENT FOR REPLACING FILTERS

DOEpatents

Blomgren, R.A.; Bohlin, N.J.C.

1957-08-27

An improved filtered air exhaust system which may be continually operated during the replacement of the filters without the escape of unfiltered air is described. This is accomplished by hermetically sealing the box like filter containers in a rectangular tunnel with neoprene covered sponge rubber sealing rings coated with a silicone impregnated pneumatic grease. The tunnel through which the filters are pushed is normal to the exhaust air duct. A number of unused filters are in line behind the filters in use, and are moved by a hydraulic ram so that a fresh filter is positioned in the air duct. The used filter is pushed into a waiting receptacle and is suitably disposed. This device permits a rapid and safe replacement of a radiation contaminated filter without interruption to the normal flow of exhaust air.

Solid-State Thyratron Replacement. Final Report

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

Roth, Ian

2017-12-12

Under this SBIR, DTI developed a solid-state switch as an alternative to legacy thyratron equipment. Our Phase II objective was to make a solid-state thyratron replacement that would provide equivalent or better performance, much higher reliability (at least a 20 year lifetime, compared to a thyratron’s two-year lifetime) and would sell for ~3x the cost of a thyratron, or less than $40k. We were successful in building a solid-state switch which could reliably function as a thyratron replacement. The unit was designed to directly replace the thyratrons currently being used at SLAC’s Linac Coherent Light Source (LCLS), and was builtmore » in a tank that was small enough to fit into the existing thyratron cabinet, providing a true form-fit-function replacement path. We tested the switch at the full operating specifications: 48 kV, 6.3 kA, and 1 µs risetime. We also demonstrated a peak-to-peak pulse jitter of 1.5 ns, which is five times shorter than is typical for thyratrons. This lower jitter would improve the performance of the LCLS beam. The predicted reliability is more than 80 years, which is 40 times greater than a thyratron.« less

42 CFR 433.117 - Initial approval of replacement systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... and Information Retrieval Systems § 433.117 Initial approval of replacement systems. (a) A replacement system must meet all conditions of initial approval of a mechanized claims processing and information retrieval system. (b) The agency must submit a APD that includes— (1) The date the replacement system will...

48 CFR 908.7101-4 - Replacement of motor vehicles.

Code of Federal Regulations, 2014 CFR

2014-10-01

... vehicles. 908.7101-4 Section 908.7101-4 Federal Acquisition Regulations System DEPARTMENT OF ENERGY....7101-4 Replacement of motor vehicles. (a) The replacement of motor vehicles shall be in accordance with... Activities may arrange to sell, as exchange sales, used motor vehicles being replaced and to apply the...

48 CFR 908.7101-4 - Replacement of motor vehicles.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Replacement of motor....7101-4 Replacement of motor vehicles. (a) The replacement of motor vehicles shall be in accordance with... Heads of Contracting Activities may arrange to sell, as exchange sales, used motor vehicles being...

Slab replacement maturity guidelines.

DOT National Transportation Integrated Search

2014-04-01

This study investigated the use of maturity method to determine early age strength of concrete in slab : replacement application. Specific objectives were (1) to evaluate effects of various factors on the compressive : maturity-strength relationship ...

Hereditary hemochromatosis as a risk factor for joint replacement surgery.

PubMed

Sahinbegovic, Enijad; Dallos, Tomás; Aigner, Elmar; Axmann, Roland; Engelbrecht, Matthias; Schöniger-Hekele, Maximilian; Karonitsch, Thomas; Farkas, Martin; Karger, Thomas; Willeit, Johann; Stölzel, Ulrich; Keysser, Gernot; Datz, Christian; Kiechl, Stefan; Schett, Georg; Zwerina, Jochen

2010-07-01

Hemochromatosis is an inherited disease with iron overload and joint involvement resembling osteoarthritis. To determine the rate of joint replacement surgery in patients with hemochromatosis, we performed a cross-sectional cohort study. A total of 199 individuals with hereditary hemochromatosis were included. The prevalence of joint replacement surgery in hip, knee, and ankle joints because of secondary osteoarthritis was assessed. Data were compared with 917 healthy subjects from the population-based Bruneck study. A total of 32 of 199 individuals with hemochromatosis received joint replacement surgery with a total number of 52 joints replaced. Compared with expected rates in healthy individuals, patients with hemochromatosis had a significantly higher risk for joint replacement surgery (odds ratio 9.0; confidence interval, 4.6-17.4). Joint replacement occurred significantly earlier in life in patients with hemochromatosis; 21.9% of the patients with hemochromatosis and 1.7% of healthy individuals required joint replacement before the age of 50 years (P=.0027). Moreover, patients with hemochromatosis were more likely to require multiple joint replacements (8.5%) than the control group (expected rate 0.3%; P=.0001). Hemochromatosis is a risk factor for joint replacement surgery because of severe secondary osteoarthritis. Copyright 2010 Elsevier Inc. All rights reserved.

Effect of different signal-processing options on speech-in-noise recognition for cochlear implant recipients with the cochlear CP810 speech processor.

PubMed

Potts, Lisa G; Kolb, Kelly A

2014-04-01

Difficulty understanding speech in the presence of background noise is a common report among cochlear implant (CI) recipients. Several speech-processing options designed to improve speech recognition, especially in noise, are currently available in the Cochlear Nucleus CP810 speech processor. These include adaptive dynamic range optimization (ADRO), autosensitivity control (ASC), Beam, and Zoom. The purpose of this study was to evaluate CI recipients' speech-in-noise recognition to determine which currently available processing option or options resulted in best performance in a simulated restaurant environment. Experimental study with one study group. The independent variable was speech-processing option, and the dependent variable was the reception threshold for sentences score. Thirty-two adult CI recipients. Eight processing options were tested: Beam, Beam + ASC, Beam + ADRO, Beam + ASC + ADRO, Zoom, Zoom + ASC, Zoom + ADRO, and Zoom + ASC + ADRO. Participants repeated Hearing in Noise Test sentences presented at a 0° azimuth, with R-Space restaurant noise presented from a 360° eight-loudspeaker array at 70 dB sound pressure level. A one-way repeated-measures analysis of variance was used to analyze differences in Beam options, Zoom options, and Beam versus Zoom options. Among the Beam options, Beam + ADRO was significantly poorer than Beam only, Beam + ASC, and Beam + ASC + ADRO. A 1.6-dB difference was observed between the best (Beam only) and poorest (Beam + ADRO) options. Among the Zoom options, Zoom only and Zoom + ADRO were significantly poorer than Zoom + ASC. A 2.2-dB difference was observed between the best (Zoom + ASC) and poorest (Zoom only) options. The comparison between Beam and Zoom options showed one significant difference, with Zoom only significantly poorer than Beam only. No significant difference was found between the other Beam and Zoom options (Beam + ASC vs Zoom + ASC, Beam + ADRO vs Zoom + ADRO, and Beam + ASC + ADRO vs Zoom + ASC

Long-working-distance fluorescence microscope with high-numerical-aperture objectives for variable-magnification imaging in live mice from macro- to subcellular

NASA Astrophysics Data System (ADS)

Kimura, Hiroaki; Momiyama, Masashi; Tomita, Katsuro; Tsuchiya, Hiroyuki; Hoffman, Robert M.

2010-11-01

We demonstrate the development of a long-working-distance fluorescence microscope with high-numerical-aperture objectives for variable-magnification imaging in live mice from macro- to subcellular. To observe cytoplasmic and nuclear dynamics of cancer cells in the living mouse, 143B human osteosarcoma cells are labeled with green fluorescent protein in the nucleus and red fluorescent protein in the cytoplasm. These dual-color cells are injected by a vascular route in an abdominal skin flap in nude mice. The mice are then imaged with the Olympus MVX10 macroview fluorescence microscope. With the MVX10, the nuclear and cytoplasmic behavior of cancer cells trafficking in blood vessels of live mice is observed. We also image lung metastases in live mice from the macro- to the subcellular level by opening the chest wall and imaging the exposed lung in live mice. Injected splenocytes, expressing cyan fluorescent protein, could also be imaged on the lung of live mice. We demonstrate that the MVX10 microscope offers the possibility of full-range in vivo fluorescence imaging from macro- to subcellular and should enable widespread use of powerful imaging technologies enabled by genetic reporters and other fluorophores.

46 CFR 59.01-5 - Repairs, replacements, or alterations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Repairs, replacements, or alterations. 59.01-5 Section 59.01-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING REPAIRS TO BOILERS, PRESSURE VESSELS AND APPURTENANCES General Requirements § 59.01-5 Repairs, replacements, or alterations. (a) No repairs, replacements, or...

46 CFR 59.01-5 - Repairs, replacements, or alterations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Repairs, replacements, or alterations. 59.01-5 Section 59.01-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING REPAIRS TO BOILERS, PRESSURE VESSELS AND APPURTENANCES General Requirements § 59.01-5 Repairs, replacements, or alterations. (a) No repairs, replacements, or...

46 CFR 59.01-5 - Repairs, replacements, or alterations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Repairs, replacements, or alterations. 59.01-5 Section 59.01-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING REPAIRS TO BOILERS, PRESSURE VESSELS AND APPURTENANCES General Requirements § 59.01-5 Repairs, replacements, or alterations. (a) No repairs, replacements, or...

46 CFR 59.01-5 - Repairs, replacements, or alterations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Repairs, replacements, or alterations. 59.01-5 Section 59.01-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING REPAIRS TO BOILERS, PRESSURE VESSELS AND APPURTENANCES General Requirements § 59.01-5 Repairs, replacements, or alterations. (a) No repairs, replacements, or...

46 CFR 59.01-5 - Repairs, replacements, or alterations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Repairs, replacements, or alterations. 59.01-5 Section 59.01-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING REPAIRS TO BOILERS, PRESSURE VESSELS AND APPURTENANCES General Requirements § 59.01-5 Repairs, replacements, or alterations. (a) No repairs, replacements, or...

Hip or knee replacement - after - what to ask your doctor

MedlinePlus

... chap 7. Read More Hip joint replacement Hip pain Knee joint replacement Knee pain Osteoarthritis Patient Instructions Getting your home ready - knee or hip surgery Hip or knee replacement - before - ...

Hip or knee replacement - before - what to ask your doctor

MedlinePlus

... chap 7. Read More Hip joint replacement Hip pain Knee joint replacement Knee pain Osteoarthritis Patient Instructions Getting your home ready - knee or hip surgery Hip or knee replacement - after - ...

Is physiological glucocorticoid replacement important in children?

PubMed Central

Porter, John; Blair, Joanne; Ross, Richard J

2017-01-01

Cortisol has a distinct circadian rhythm with low concentrations at night, rising in the early hours of the morning, peaking on waking and declining over the day to low concentrations in the evening. Loss of this circadian rhythm, as seen in jetlag and shift work, is associated with fatigue in the short term and diabetes and obesity in the medium to long term. Patients with adrenal insufficiency on current glucocorticoid replacement with hydrocortisone have unphysiological cortisol concentrations being low on waking and high after each dose of hydrocortisone. Patients with adrenal insufficiency complain of fatigue, a poor quality of life and there is evidence of poor health outcomes including obesity potentially related to glucocorticoid replacement. New technologies are being developed that deliver more physiological glucocorticoid replacement including hydrocortisone by subcutaneous pump, Plenadren, a once-daily modified-release hydrocortisone and Chronocort, a delayed and sustained absorption hydrocortisone formulation that replicates the overnight profile of cortisol. In this review, we summarise the evidence regarding physiological glucocorticoid replacement with a focus on relevance to paediatrics. PMID:27582458

Consistency in trophic magnification factors of cyclic methyl siloxanes in pelagic freshwater food webs leading to brown trout.

PubMed

Borgå, Katrine; Fjeld, Eirik; Kierkegaard, Amelie; McLachlan, Michael S

2013-12-17

Cyclic volatile methyl siloxanes (cVMS) concentrations were analyzed in the pelagic food web of two Norwegian lakes (Mjøsa, Randsfjorden), and in brown trout (Salmo trutta) and Arctic char (Salvelinus alpinus) collected in a reference lake (Femunden), in 2012. Lakes receiving discharge from wastewater treatment plants (Mjøsa and Randsfjorden) had cVMS concentrations in trout that were up to 2 orders of magnitude higher than those in Femunden, where most samples were close to the limit of quantification (LOQ). Food web biomagnification of cVMS in Mjøsa and Randsfjorden was quantified by estimation of trophic magnification factors (TMFs). TMF for legacy persistent organic pollutants (POPs) were analyzed for comparison. Both decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) biomagnified with TMFs of 2.9 (2.1-4.0) and 2.3 (1.8-3.0), respectively. Octamethylcyclotetrasiloxane (D4) was below the LOQ in the majority of samples and had substantially lower biomagnification than for D5 and D6. The cVMS TMFs did not differ between the lakes, whereas the legacy POP TMFs were higher in Mjøsa than inRandsfjorden. Whitefish had lower cVMS bioaccumulation compared to legacy POPs, and affected the TMF significance for cVMS, but not for POPs. TMFs of D5 and legacy contaminants in Lake Mjøsa were consistent with those previously measured in Mjøsa.

Mastracchio during EMU FPS Remove and Replace OPS

NASA Image and Video Library

2014-04-14

Expedition 39 flight engineer Rick Mastracchio poses for a photo with the replacement Fan Pump Separator (FPS) and Extravehicular Mobility Unit (EMU) 3005. Image was taken in the Quest Airlock (A/L) during FPS remove and replace operations.

Roguing with replacement in perennial crops: conditions for successful disease management.

PubMed

Sisterson, Mark S; Stenger, Drake C

2013-02-01

Replacement of diseased plants with healthy plants is commonly used to manage spread of plant pathogens in perennial cropping systems. This strategy has two potential benefits. First, removing infected plants may slow pathogen spread by eliminating inoculum sources. Second, replacing infected plants with uninfected plants may offset yield losses due to disease. The extent to which these benefits are realized depends on multiple factors. In this study, sensitivity analyses of two spatially explicit simulation models were used to evaluate how assumptions concerning implementation of a plant replacement program and pathogen spread interact to affect disease suppression. In conjunction, effects of assumptions concerning yield loss associated with disease and rates of plant maturity on yields were simultaneously evaluated. The first model was used to evaluate effects of plant replacement on pathogen spread and yield on a single farm, consisting of a perennial crop monoculture. The second model evaluated effects of plant replacement on pathogen spread and yield in a 100 farm crop growing region, with all farms maintaining a monoculture of the same perennial crop. Results indicated that efficient replacement of infected plants combined with a high degree of compliance among farms effectively slowed pathogen spread, resulting in replacement of few plants and high yields. In contrast, inefficient replacement of infected plants or limited compliance among farms failed to slow pathogen spread, resulting in replacement of large numbers of plants (on farms practicing replacement) with little yield benefit. Replacement of infected plants always increased yields relative to simulations without plant replacement provided that infected plants produced no useable yield. However, if infected plants produced useable yields, inefficient removal of infected plants resulted in lower yields relative to simulations without plant replacement for perennial crops with long maturation periods

Total Knee Replacement

PubMed Central

2005-01-01

Executive Summary Objective The aim of this review was to assess the effectiveness, in terms of pain reduction and functional improvement, and costing of total knee replacement (TKR) for people with osteoarthritis for whom less invasive treatments (such as physiotherapy, analgesics, anti-inflammatory drugs, intra-articular steroids, hyaluronic acids, and arthroscopic surgery) have failed. Clinical Need Osteoarthritis affects an estimated 10% to 12% of Canadian adults. The therapeutic goals of osteoarthritis treatment are to improve joint mobility and reduce pain. Stepwise treatment options include exercise, weight loss, physiotherapy, analgesics, anti-inflammatory drugs, intra-articular steroids and hyaluronic acids, arthroscopic surgery, and, in severe cases, total joint replacement with follow-up rehabilitation. These treatments are delivered by a range of health care professionals, including physiotherapists, occupational therapists, family physicians, internists, rheumatologists, and orthopedic surgeons. TKR is an end-of-line treatment for patients with severe pain and functional limitations. More women than men undergo knee replacement, and most patients are between 55 and 84 years old. The Technology TKR is a surgical procedure in which an artificial joint or prosthesis replaces a damaged knee joint. The primary indication for TKR is pain, followed by functional limitation. Usually, a person’s daily activities must be substantially affected by pain and functional limitations for him or her to be considered a candidate for TKR. There are 3 different types of knee replacement prostheses. Non-constrained prostheses use the patient’s ligaments and muscles to provide the stability for the prosthesis. Semi-constrained prostheses provide some stability for the knee and do not rely entirely on the patient’s ligaments and muscles to provide the stability. Constrained prostheses are for patients whose ligaments and muscles are not able to provide stability for

Replacement of Mushroom Cage Gastrostomy Tube Using a Modified Technique to Allow Percutaneous Replacement with an Endoscopic Tube in Patients with Amyotrophic Lateral Sclerosis

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

Ammar, Thoraya; Rio, Alan; Ampong, Mary Ann

2010-06-15

Radiologic inserted gastrostomy (RIG) is the preferred method in our institution for enteral feeding in amyotrophic lateral sclerosis (ALS). Skin-level primary-placed mushroom cage gastrostomy tubes become tight with weight gain. We describe a minimally invasive radiologic technique for replacing mushroom gastrostomy tubes with endoscopic mushroom cage tubes in ALS. All patients with ALS who underwent replacement of a RIG tube were included. Patients were selected for a modified replacement when the tube length of the primary placed RIG tube was insufficient to allow like-for-like replacement. Replacement was performed under local anesthetic and fluoroscopic guidance according to a preset technique, withmore » modification of an endoscopic mushroom cage gastrostomy tube to allow percutaneous placement. Assessment of the success, safety, and durability of the modified technique was undertaken. Over a 60-month period, 104 primary placement mushroom cage tubes in ALS were performed. A total of 20 (19.2%) of 104 patients had a replacement tube positioned, 10 (9.6%) of 104 with the modified technique (male n = 4, female n = 6, mean age 65.5 years, range 48-85 years). All tubes were successfully replaced using this modified technique, with two minor complications (superficial wound infection and minor hemorrhage). The mean length of time of tube durability was 158.5 days (range 6-471 days), with all but one patient dying with a functional tube in place. We have devised a modification to allow percutaneous replacement of mushroom cage gastrostomy feeding tubes with minimal compromise to ALS patients. This technique allows tube replacement under local anesthetic, without the need for sedation, an important consideration in ALS.« less

Final Environmental Assessment, Horse Creek Bridge Replacement

DTIC Science & Technology

2010-10-01

Final Environmental Assessment Horse Creek Bridge Replacement 78th Civil Engineer Group...Final Environmental Assessment Horse Creek Bridge Replacement 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 FINDING OF NO SIGNIFICANT IMPACT (FONSI)/ FINDING OF NO PRACTICABLE ALTERNATIVE (FONP A) HORSE

Design of high-performance adaptive objective lens with large optical depth scanning range for ultrabroad near infrared microscopic imaging

PubMed Central

Lan, Gongpu; Mauger, Thomas F.; Li, Guoqiang

2015-01-01

We report on the theory and design of adaptive objective lens for ultra broadband near infrared light imaging with large dynamic optical depth scanning range by using an embedded tunable lens, which can find wide applications in deep tissue biomedical imaging systems, such as confocal microscope, optical coherence tomography (OCT), two-photon microscopy, etc., both in vivo and ex vivo. This design is based on, but not limited to, a home-made prototype of liquid-filled membrane lens with a clear aperture of 8mm and the thickness of 2.55mm ~3.18mm. It is beneficial to have an adaptive objective lens which allows an extended depth scanning range larger than the focal length zoom range, since this will keep the magnification of the whole system, numerical aperture (NA), field of view (FOV), and resolution more consistent. To achieve this goal, a systematic theory is presented, for the first time to our acknowledgment, by inserting the varifocal lens in between a front and a back solid lens group. The designed objective has a compact size (10mm-diameter and 15mm-length), ultrabroad working bandwidth (760nm - 920nm), a large depth scanning range (7.36mm in air) — 1.533 times of focal length zoom range (4.8mm in air), and a FOV around 1mm × 1mm. Diffraction-limited performance can be achieved within this ultrabroad bandwidth through all the scanning depth (the resolution is 2.22 μm - 2.81 μm, calculated at the wavelength of 800nm with the NA of 0.214 - 0.171). The chromatic focal shift value is within the depth of focus (field). The chromatic difference in distortion is nearly zero and the maximum distortion is less than 0.05%. PMID:26417508

Dead pixel replacement in LWIR microgrid polarimeters.

PubMed

Ratliff, Bradley M; Tyo, J Scott; Boger, James K; Black, Wiley T; Bowers, David L; Fetrow, Matthew P

2007-06-11

LWIR imaging arrays are often affected by nonresponsive pixels, or "dead pixels." These dead pixels can severely degrade the quality of imagery and often have to be replaced before subsequent image processing and display of the imagery data. For LWIR arrays that are integrated with arrays of micropolarizers, the problem of dead pixels is amplified. Conventional dead pixel replacement (DPR) strategies cannot be employed since neighboring pixels are of different polarizations. In this paper we present two DPR schemes. The first is a modified nearest-neighbor replacement method. The second is a method based on redundancy in the polarization measurements.We find that the redundancy-based DPR scheme provides an order-of-magnitude better performance for typical LWIR polarimetric data.

Importance of milk replacer intake and composition in rearing orphan foals

PubMed Central

Cymbaluk, Nadia F.; Smart, Marion E.; Bristol, Frank M.; Pouteaux, Victor A.

1993-01-01

Effects of milk replacer composition and intake on the growth of orphan foals were evaluated. Twenty foals were assigned to four treatments: 1) mare-nursed, 2) commercial foal milk replacer at recommended intakes (standard), 3) commercial foal milk replacer at high intakes (high), and 4) acidified replacer at recommended intakes (acidified). Foals fed milk replacer diets were weaned at 12-24 hours postpartum and fed milk replacer for 50 days. Mare-nursed foals were weaned between 52 and 56 days of age. Foals fed replacer diets gained 12% to 28% less weight than mare-nursed foals up to two weeks of age. However, by four months of age, weights of replacer-fed foals were similar to those of mare-nursed foals and 32 other mare-nursed foals at the farm weaned between three and four months postparium. Foals drank 10 to 12 L/100 kg body weight (BW) in fluid replacer daily over the trial period. During the first week, high intake foals consumed 26% more replacer (p<0.05) than foals fed acidified or standard diets. This higher intake resulted in diarrhea earlier (6-11 days vs 11-22 days) and for a longer time (6.3 days vs 2.5-3.6 days) than in foals fed recommended amounts. Mare-nursed foals developed “foal heat scours” in the second week postpartum. After the first week, foals fed high replacer diet voluntarily consumed the same volume of fluid replacer as foals fed the standard intake. Foals ate less than 1 kg grain mix/100 kg BW daily to one month of age, then increased intake to 1.5-2 kg/ 100 kg BW to weaning. Water intake was 20-40% of daily fluid intake and was correlated (r = 0.85) to dry matter intake. Foals in the high intake group ate less (p<0.05) solid feed and drank less water than foals fed the standard and acidified diets. The foal's stomach capacity appears to limit meal size and thus replacer intake. If recommended feeding intervals are used, replacer intakes by foals are less than 15% BW daily. High volume intakes appeared to prolong diarrhea. Normal

23 CFR 650.407 - Application for bridge replacement or rehabilitation.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false Application for bridge replacement or rehabilitation... ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.407 Application for bridge replacement or rehabilitation. (a) Agencies participate...

23 CFR 650.407 - Application for bridge replacement or rehabilitation.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Application for bridge replacement or rehabilitation... ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.407 Application for bridge replacement or rehabilitation. (a) Agencies participate...

Two-level total lumbar disc replacement.

PubMed

Di Silvestre, Mario; Bakaloudis, Georgios; Lolli, Francesco; Vommaro, Francesco; Parisini, Patrizio

2009-06-01

Total lumbar disc replacement (TDR) has been widely used as a treatment option for 2-level symptomatic degenerative disc disease. However, recent studies have presented conflicting results and some authors concluded that outcome deteriorated when disc replacement was performed bisegmentally, with an increase of complications for bisegmental replacements in comparison with monosegmental disc arthroplasty. The goal of the present retrospective study is to investigate results in a group of patients who have received bisegmental TDR with SB Charitè III artificial disc for degenerative disc disease with a minimum follow-up of 3 years, and to compare the results of 2-level disc replacement versus 1-level patients treated with the same prosthesis. A total of 32 patients had at least 3-years follow-up and were reviewed. The average age of the patients was 38.5 years. There were 11 males and 21 females. About 16 patients received 2-level TDR (SB Charitè III) and 16 received 1-level TDR (SB Charitè III). Both radiographic and functional outcome analysis, including patient's satisfaction, was performed. There were no signs of degenerative changes of the adjacent segments in any case of the 2- or 1-level TDR. There was no statistically significant difference between 2- and 1-level TDR both at 12 months and at 3-years follow-up on functional outcome scores. There was a statistically insignificant difference concerning the patients satisfaction between 1- and 2-level surgeries at the last follow-up (P = 0.46). In the 2-level TDR patients, there were 5 minor complications (31.25%), whereas major complications occurred in 4 more patients (25%) and required a new surgery in 2 cases (12.5%). In the 1-level cases there were 2 minor complications (12.5%) and 2 major complications (12.5%) and a new revision surgery was required in 1 patient (6.25%). In conclusion, the use of 2-level disc replacement at last follow-up presented a higher incidence of complications than in cases with 1

Heart valve replacement with the Sorin tilting-disc prosthesis. A 10-year experience.

PubMed

Milano, A; Bortolotti, U; Mazzucco, A; Mossuto, E; Testolin, L; Thiene, G; Gallucci, V

1992-02-01

From 1978 to 1988, 697 patients with a mean age of 48 +/- 11 years (range 5 to 75 years) received a Sorin tilting-disc prosthesis; 358 had had aortic valve replacement, 247 mitral valve replacement, and 92 mitral and aortic valve replacement. Operative mortality rates were 7.8%, 11.3%, and 10.8%, respectively, in the three groups. Cumulative duration of follow-up is 1650 patient-years for aortic valve replacement (maximum follow-up 11.4 years), 963 patient-years for mitral valve replacement (maximum follow-up 9.9 years) and 328 patient-years for mitral and aortic valve replacement (maximum follow-up 9.4 years). Actuarial survival at 9 years is 72% +/- 4% after mitral valve replacement, 70% +/- 3% after aortic valve replacement, and 50% +/- 12% after mitral and aortic valve replacement, and actuarial freedom from valve-related deaths is 97% +/- 2% after mitral valve replacement, 92% +/- 2% after aortic valve replacement, and 62% +/- 15% after mitral and aortic valve replacement. Thromboembolic events occurred in 21 patients with aortic valve replacement (1.3% +/- 0.2%/pt-yr), in 12 with mitral valve replacement (1.2% +/- 0.3% pt-yr), and in seven with mitral and aortic valve replacement (2.1% +/- 0.8%), with one case of prosthetic thrombosis in each group; actuarial freedom from thromboembolism at 9 years is 92% +/- 3% after mitral valve replacement, 91% +/- 3% after aortic valve replacement, and 74% +/- 16% after mitral and aortic valve replacement. Anticoagulant-related hemorrhage was observed in 15 patients after aortic valve replacement (0.9% +/- 0.2%/pt-yr), in 9 after mitral valve replacement (0.9% +/- 0.3%/pt-yr), and in 6 with mitral and aortic valve replacement (0.9% +/- 0.5%/pt-yr); actuarial freedom from this complication at 9 years is 94% +/- 2% after aortic valve replacement, 91% +/- 4% after mitral valve replacement, and 68% +/- 16% after mitral and aortic valve replacement. Actuarial freedom from reoperation at 9 years is 97% +/- 2% after mitral and

Recent Advances in Hydrocortisone Replacement Treatment.

PubMed

Mallappa, Ashwini; Debono, Miguel

2016-01-01

Since the first use of cortisone in patients around 65 years ago, the use of synthetic glucocorticoids has made a crucial impact on the treatment of several diseases in medicine. Although significant reductions in morbidity and mortality have occurred in patients suffering from cortisol deficiency, conventional hydrocortisone replacement treatment is still inadequate. A major limitation is that it fails to replace cortisol in a physiological manner. Cortisol has a distinct circadian rhythm and acts as a secondary messenger synchronizing the central to peripheral clocks, hence playing a key role in biological processes and the circadian timing system. Circadian misalignment has been associated with ill-health and so nonphysiological glucocorticoid treatment could explain the increased mortality rate, poor quality of life and metabolic complications in patients suffering from adrenal insufficiency. Attempts at replacing cortisol in a physiological manner have shown significant progress in the past decade with the development of modified-release formulations of hydrocortisone (Chronocort® and Plenadren®) and continuous subcutaneous hydrocortisone infusions. Initial studies investigating the use of these replacement regimens are promising, demonstrating both clinical and biochemical improvement. Larger studies are needed to determine whether this novel approach enhances long-term outcomes in both children and adults with cortisol deficiency. This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply. Published by S. Karger AG, Basel.

COMPUTER AIDED DESIGN OF REPLACEMENT SOLVENTS UNDER VARYING ENVIRONMENTAL CONSTRAINTS

EPA Science Inventory

There is a great need to replace many solvents that are commonly used by industry and the public, but whose continued use entails a number of human health and environmental risks. One problem hampering solvent replacement is the thought that replacement, particularly for environm...

Menopausal Symptom Relief and Side Effects Experienced by Women Using Bioidentical Hormone Replacement Therapy and Synthetic Conjugated Equine Estrogen and/or Progestin Hormone Replacement Therapy, Part 1.

PubMed

Deleruyelle, Laura J

2016-01-01

The use of compounded bioidentical hormone replacement therapy by menopausal women has become a popular alternative to traditional synthetic conjugated equine estrogen and progestin hormone replacement therapy due to safety concerns raised by recent studies. However, due to the lack of randomized, large-scale trials to evaluate the efficacy and side-effect profile of compounded bioidentical hormone replacement therapy many healthcare providers are reluctant to prescribe such therapy. The purpose of this study was to compare women's menopausal symptom relief and side effects experienced when using compounded bioidentical hormone replacement therapy and traditional hormone replacement therapy. A descriptive comparative design was used. Inferential and descriptive statistical procedures including a paired difference t -test, two-sample t -test, and f tests (percentage, mean, standard deviation, frequency) were run on the Statistical Package for the Social Sciences. The framework used to guide this study was Lenz and Pugh's Theory of Unpleasant Symptoms. Surveys were distributed once to a convenient sample of women aged 35 and older when they dropped off or picked up their prescriptions at a pharmacy. Of the 216 surveys distributed, 70 were returned from those women taking compounded bioidentical hormone replacement therapy and 53 from traditional hormone replacement therapy. The survey contained 15 questions pertaining to age, duration of hormone replacement therapy, type and formulation of hormone replacement therapy, reasons for initiating hormone replacement therapy, symptoms before and one month after hormone replacement therapy, and side effects related to hormone replacement therapy. The results of this study will be summarized in forthcoming articles in this series. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

Sugar replacers: from technological challenges to consequences on health.

PubMed

Lê, Kim-Anne; Robin, Frédéric; Roger, Olivier

2016-07-01

Dietary sugars play a role in noncommunicable diseases and represent a clear target for reduction. In this context, product reformulation can have a positive impact on health. Several technological solutions are available to replace sugar, all with benefits and limitations. The goal of this review is to describe the main sugar replacement alternatives and discuss their impact on health and product physicochemical properties. Although high intensity sweeteners and polyols have been used for a long time to replace sucrose and despite no clear evidence of harm, the trend is today to look for alternatives such as sweet enhancers or alternative sugars such as allulose or tagatose, which are both low caloric. To replace the physical properties of sugars, new trends are to substitute widely used maltodextrins by dietary fibres to confer added health benefits. A wide range of solutions is currently available to replace dietary sugars and compensate for the impact on bulking properties and sweetness profile of food products.

Polyp detection rates using magnification with narrow band imaging and white light.

PubMed

Gilani, Nooman; Stipho, Sally; Panetta, James D; Petre, Sorin; Young, Michele A; Ramirez, Francisco C

2015-05-16

To compare the yield of adenomas between narrow band imaging and white light when using high definition/magnification. This prospective, non-randomized comparative study was performed at the endoscopy unit of veteran affairs medical center in Phoenix, Arizona. Consecutive patients undergoing first average risk colorectal cancer screening colonoscopy were selected. Two experienced gastroenterologists performed all the procedures that were blinded to each other's findings. Demographic details were recorded. Data are presented as mean ± SEM. Proportional data were compared using the χ(2) test and means were compared using the Student's t test. Tandem colonoscopy was performed in a sequential and segmental fashion using one of 3 strategies: white light followed by narrow band imaging [Group A: white light (WL) → narrow band imaging (NBI)]; narrow band imaging followed by white light (Group B: NBI → WL) and, white light followed by white light (Group C: WL → WL). Detection rate of missed polyps and adenomas were evaluated in all three groups. Three hundred patients were studied (100 in each Group). Although the total time for the colonoscopy was similar in the 3 groups (23.8 ± 0.7, 22.2 ± 0.5 and 24.1 ± 0.7 min for Groups A, B and C, respectively), it reached statistical significance between Groups B and C (P < 0.05). The cecal intubation time in Groups B and C was longer than for Group A (6.5 ± 0.4 min and 6.5 ± 0.4 min vs 4.9 ± 0.3 min; P < 0.05). The withdrawal time for Groups A and C was longer than Group B (18.9 ± 0.7 min and 17.6 ± 0.6 min vs 15.7 ± 0.4 min; P < 0.05). Overall miss rate for polyps and adenomas detected in three groups during the second look was 18% and 17%, respectively (P = NS). Detection rate for polyps and adenomas after first look with white light was similar irrespective of the light used during the second look (WL → WL: 13.7% for polyps, 12.6% for adenomas; WL → NBI: 14.2% for polyps, 11.3% for adenomas). Miss rate of

Hip Replacement - Multiple Languages

MedlinePlus

... Hip Replacement - العربية (Arabic) Bilingual PDF Health Information Translations Chinese, Simplified (Mandarin dialect) (简体中文) Expand Section Total ... Chinese, Simplified (Mandarin dialect)) Bilingual PDF Health Information Translations Chinese, Traditional (Cantonese dialect) (繁體中文) Expand Section Total ...

VH Replacement Footprint Analyzer-I, a Java-Based Computer Program for Analyses of Immunoglobulin Heavy Chain Genes and Potential VH Replacement Products in Human and Mouse

PubMed Central

Huang, Lin; Lange, Miles D.; Zhang, Zhixin

2014-01-01

VH replacement occurs through RAG-mediated secondary recombination between a rearranged VH gene and an upstream unrearranged VH gene. Due to the location of the cryptic recombination signal sequence (cRSS, TACTGTG) at the 3′ end of VH gene coding region, a short stretch of nucleotides from the previous rearranged VH gene can be retained in the newly formed VH–DH junction as a “footprint” of VH replacement. Such footprints can be used as markers to identify Ig heavy chain (IgH) genes potentially generated through VH replacement. To explore the contribution of VH replacement products to the antibody repertoire, we developed a Java-based computer program, VH replacement footprint analyzer-I (VHRFA-I), to analyze published or newly obtained IgH genes from human or mouse. The VHRFA-1 program has multiple functional modules: it first uses service provided by the IMGT/V-QUEST program to assign potential VH, DH, and JH germline genes; then, it searches for VH replacement footprint motifs within the VH–DH junction (N1) regions of IgH gene sequences to identify potential VH replacement products; it can also analyze the frequencies of VH replacement products in correlation with publications, keywords, or VH, DH, and JH gene usages, and mutation status; it can further analyze the amino acid usages encoded by the identified VH replacement footprints. In summary, this program provides a useful computation tool for exploring the biological significance of VH replacement products in human and mouse. PMID:24575092

Semantic Factors Predict the Rate of Lexical Replacement of Content Words

PubMed Central

Vejdemo, Susanne; Hörberg, Thomas

2016-01-01

The rate of lexical replacement estimates the diachronic stability of word forms on the basis of how frequently a proto-language word is replaced or retained in its daughter languages. Lexical replacement rate has been shown to be highly related to word class and word frequency. In this paper, we argue that content words and function words behave differently with respect to lexical replacement rate, and we show that semantic factors predict the lexical replacement rate of content words. For the 167 content items in the Swadesh list, data was gathered on the features of lexical replacement rate, word class, frequency, age of acquisition, synonyms, arousal, imageability and average mutual information, either from published databases or gathered from corpora and lexica. A linear regression model shows that, in addition to frequency, synonyms, senses and imageability are significantly related to the lexical replacement rate of content words–in particular the number of synonyms that a word has. The model shows no differences in lexical replacement rate between word classes, and outperforms a model with word class and word frequency predictors only. PMID:26820737

Esophageal replacement in children: Challenges and long-term outcomes.

PubMed

Soccorso, Giampiero; Parikh, Dakshesh H

2016-01-01

Replacement of a nonexistent or damaged esophagus continues to pose a significant challenge to pediatric surgeons. Various esophageal replacement grafts and techniques have not produced consistently good outcomes to emulate normal esophagus. Therefore, many techniques are still being practiced and recommended with no clear consensus. We present a concise literature review of the currently used techniques and with discussions on the advantages and anticipated morbidity. There are no randomized controlled pediatric studies to compare different types of esophageal replacements. Management and graft choice are based on geographical and personal predilections rather than on any discernible objective data. The biggest series with long-term outcome are reported for gastric transposition and colonic replacement. Comparison of different studies shows no significant difference in early (graft necrosis and anastomotic leaks) or late complications (strictures, poor feeding, gastro-esophageal reflux, tortuosity of the graft, and Barrett's esophagus). The biggest series seem to have lower complications than small series reflecting the decennials experience in their respective centers. Long-term follow-up is recommended following esophageal replacement for the development of late strictures, excessive tortuosity, and Barrett's changes within the graft. Once child overcomes initial morbidity and establishes oral feeding, long-term consequences and complications of pediatric esophageal replacement should be monitored and managed in adult life.

Esophageal replacement in children: Challenges and long-term outcomes

PubMed Central

Soccorso, Giampiero; Parikh, Dakshesh H.

2016-01-01

Replacement of a nonexistent or damaged esophagus continues to pose a significant challenge to pediatric surgeons. Various esophageal replacement grafts and techniques have not produced consistently good outcomes to emulate normal esophagus. Therefore, many techniques are still being practiced and recommended with no clear consensus. We present a concise literature review of the currently used techniques and with discussions on the advantages and anticipated morbidity. There are no randomized controlled pediatric studies to compare different types of esophageal replacements. Management and graft choice are based on geographical and personal predilections rather than on any discernible objective data. The biggest series with long-term outcome are reported for gastric transposition and colonic replacement. Comparison of different studies shows no significant difference in early (graft necrosis and anastomotic leaks) or late complications (strictures, poor feeding, gastro-esophageal reflux, tortuosity of the graft, and Barrett's esophagus). The biggest series seem to have lower complications than small series reflecting the decennials experience in their respective centers. Long-term follow-up is recommended following esophageal replacement for the development of late strictures, excessive tortuosity, and Barrett's changes within the graft. Once child overcomes initial morbidity and establishes oral feeding, long-term consequences and complications of pediatric esophageal replacement should be monitored and managed in adult life. PMID:27365900

7 CFR 274.6 - Replacement issuances and cards to households.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 4 2014-01-01 2014-01-01 false Replacement issuances and cards to households. 274.6 Section 274.6 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION... Excessive Replacement Card Notice if they have chosen to exercise the option to withhold the replacement...

49 CFR 172.338 - Replacement of identification numbers.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 2 2013-10-01 2013-10-01 false Replacement of identification numbers. 172.338..., TRAINING REQUIREMENTS, AND SECURITY PLANS Marking § 172.338 Replacement of identification numbers. If more than one of the identification number markings on placards, orange panels, or white square-on-point...