Proceedings of the Image Understanding Workshop (18th) Held in Cambridge, Massachusetts on 6-8 April 1988. Volume 1

DTIC Science & Technology

1988-04-01

hypercube; methods, which work best in structured scenes, and parent/ child operations run in a smaller fixed time independent spatiotemporal energy...rectangle defines a new coordinate sVstem for it, image is constructed under orthographic projection. The child links that is relative to its own...that the child rectangle can shift in the X -- V plane, rectangle in the image. At first, a noiseless image is created relative to the nominal

Controlling selective stimulations below a spinal cord hemisection using brain recordings with a neural interface system approach

NASA Astrophysics Data System (ADS)

Panetsos, Fivos; Sanchez-Jimenez, Abel; Torets, Carlos; Largo, Carla; Micera, Silvestro

2011-08-01

In this work we address the use of realtime cortical recordings for the generation of coherent, reliable and robust motor activity in spinal-lesioned animals through selective intraspinal microstimulation (ISMS). The spinal cord of adult rats was hemisectioned and groups of multielectrodes were implanted in both the central nervous system (CNS) and the spinal cord below the lesion level to establish a neural system interface (NSI). To test the reliability of this new NSI connection, highly repeatable neural responses recorded from the CNS were used as a pattern generator of an open-loop control strategy for selective ISMS of the spinal motoneurons. Our experimental procedure avoided the spontaneous non-controlled and non-repeatable neural activity that could have generated spurious ISMS and the consequent undesired muscle contractions. Combinations of complex CNS patterns generated precisely coordinated, reliable and robust motor actions.

From the Golden Rectangle and Fibonacci to Pedagogy and Problem Posing

ERIC Educational Resources Information Center

Brown, Stephen I.

1976-01-01

Beginning with an analysis of the golden rectangle, the author shows how a series of problems for student investigation arise from queries concerning changes in conditions and analogous situations. (SD)

Simulation Exploration through Immersive Parallel Planes

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

Brunhart-Lupo, Nicholas J; Bush, Brian W; Gruchalla, Kenny M

We present a visualization-driven simulation system that tightly couples systems dynamics simulations with an immersive virtual environment to allow analysts to rapidly develop and test hypotheses in a high-dimensional parameter space. To accomplish this, we generalize the two-dimensional parallel-coordinates statistical graphic as an immersive 'parallel-planes' visualization for multivariate time series emitted by simulations running in parallel with the visualization. In contrast to traditional parallel coordinate's mapping the multivariate dimensions onto coordinate axes represented by a series of parallel lines, we map pairs of the multivariate dimensions onto a series of parallel rectangles. As in the case of parallel coordinates, eachmore » individual observation in the dataset is mapped to a polyline whose vertices coincide with its coordinate values. Regions of the rectangles can be 'brushed' to highlight and select observations of interest: a 'slider' control allows the user to filter the observations by their time coordinate. In an immersive virtual environment, users interact with the parallel planes using a joystick that can select regions on the planes, manipulate selection, and filter time. The brushing and selection actions are used to both explore existing data as well as to launch additional simulations corresponding to the visually selected portions of the input parameter space. As soon as the new simulations complete, their resulting observations are displayed in the virtual environment. This tight feedback loop between simulation and immersive analytics accelerates users' realization of insights about the simulation and its output.« less

Simulation Exploration through Immersive Parallel Planes: Preprint

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

Brunhart-Lupo, Nicholas; Bush, Brian W.; Gruchalla, Kenny

We present a visualization-driven simulation system that tightly couples systems dynamics simulations with an immersive virtual environment to allow analysts to rapidly develop and test hypotheses in a high-dimensional parameter space. To accomplish this, we generalize the two-dimensional parallel-coordinates statistical graphic as an immersive 'parallel-planes' visualization for multivariate time series emitted by simulations running in parallel with the visualization. In contrast to traditional parallel coordinate's mapping the multivariate dimensions onto coordinate axes represented by a series of parallel lines, we map pairs of the multivariate dimensions onto a series of parallel rectangles. As in the case of parallel coordinates, eachmore » individual observation in the dataset is mapped to a polyline whose vertices coincide with its coordinate values. Regions of the rectangles can be 'brushed' to highlight and select observations of interest: a 'slider' control allows the user to filter the observations by their time coordinate. In an immersive virtual environment, users interact with the parallel planes using a joystick that can select regions on the planes, manipulate selection, and filter time. The brushing and selection actions are used to both explore existing data as well as to launch additional simulations corresponding to the visually selected portions of the input parameter space. As soon as the new simulations complete, their resulting observations are displayed in the virtual environment. This tight feedback loop between simulation and immersive analytics accelerates users' realization of insights about the simulation and its output.« less

Ground target recognition using rectangle estimation.

PubMed

Grönwall, Christina; Gustafsson, Fredrik; Millnert, Mille

2006-11-01

We propose a ground target recognition method based on 3-D laser radar data. The method handles general 3-D scattered data. It is based on the fact that man-made objects of complex shape can be decomposed to a set of rectangles. The ground target recognition method consists of four steps; 3-D size and orientation estimation, target segmentation into parts of approximately rectangular shape, identification of segments that represent the target's functional/main parts, and target matching with CAD models. The core in this approach is rectangle estimation. The performance of the rectangle estimation method is evaluated statistically using Monte Carlo simulations. A case study on tank recognition is shown, where 3-D data from four fundamentally different types of laser radar systems are used. Although the approach is tested on rather few examples, we believe that the approach is promising.

Further Development of a Computational Vision Model for the Generation and Analysis of Photo-Realistic Scenes for Military and Civilian Virtual Reality Applications

DTIC Science & Technology

1996-02-01

rectangle in the center of the image straddling the boundary between the foreground grass and background treeline . The synthetic content of the target region...the square in the middle of the grass, the square in the middle of the tree leaves, and the square on the treeline are all synthetic textures. The...target rectangle on the treeline boundary. What was suprising was that the synthetic grass texture was not well matched in the rectangle in the grass

Targeted, activity-dependent spinal stimulation produces long-lasting motor recovery in chronic cervical spinal cord injury

PubMed Central

McPherson, Jacob G.; Miller, Robert R.; Perlmutter, Steve I.

2015-01-01

Use-dependent movement therapies can lead to partial recovery of motor function after neurological injury. We attempted to improve recovery by developing a neuroprosthetic intervention that enhances movement therapy by directing spike timing-dependent plasticity in spared motor pathways. Using a recurrent neural–computer interface in rats with a cervical contusion of the spinal cord, we synchronized intraspinal microstimulation below the injury with the arrival of functionally related volitional motor commands signaled by muscle activity in the impaired forelimb. Stimulation was delivered during physical retraining of a forelimb behavior and throughout the day for 3 mo. Rats receiving this targeted, activity-dependent spinal stimulation (TADSS) exhibited markedly enhanced recovery compared with animals receiving targeted but open-loop spinal stimulation and rats receiving physical retraining alone. On a forelimb reach and grasp task, TADSS animals recovered 63% of their preinjury ability, more than two times the performance level achieved by the other therapy groups. Therapeutic gains were maintained for 3 additional wk without stimulation. The results suggest that activity-dependent spinal stimulation can induce neural plasticity that improves behavioral recovery after spinal cord injury. PMID:26371306

Changes in tibialis anterior corticospinal properties after acute prolonged muscle vibration.

PubMed

Farabet, Adrien; Souron, Robin; Millet, Guillaume Y; Lapole, Thomas

2016-06-01

Prolonged local vibration is known to impair muscle performance. While involved mechanisms were previously evidenced at the spinal level, changes at the cortical level were also hypothesized. The aims of the present study were to investigate the effects of 30 min of 100-Hz tibialis anterior muscle vibration on force production capacities and to further identify the respective changes in spinal loop properties, descending voluntary drive and corticospinal properties. Thirteen subjects were tested before and after a vibration condition, and before and after a resting control condition. Maximal voluntary contraction (MVC) in dorsiflexion was measured. Transcranial magnetic stimulation was superimposed during MVCs to assess cortical voluntary activation (VATMS), motor-evoked potential amplitude (MEP) and cortical silent period length (CSP). MEP and CSP were also measured during 50 and 75 % MVC contractions. Spinal excitability was investigated by mean of H-reflex. There were no vibration effects on MVC (p = 0.805), maximal EMG activity (p = 0.653), VATMS (p = 1), and CSP (p = 0.877). Vibration tended to decrease MEP amplitude (p = 0.117). H-reflex amplitude was depressed following vibration (p = 0.008). Dorsiflexion maximal force production capacities were unaffected by 30 min of tibialis anterior muscle vibration, despite spinal loop and corticospinal excitabilities being reduced. These findings suggest that acute prolonged vibration has the potential to modulate corticospinal excitability of lower limb muscles without a concomitant functional consequence.

Active multiple plasmon-induced transparencies with detuned asymmetric multi-rectangle resonators

NASA Astrophysics Data System (ADS)

Liu, Dongdong; Wang, Jicheng; Lu, Jian

2016-11-01

The phenomenon of plasmon-induced transparency (PIT) is realized in surface plasmon polariton waveguide at the visible and near-infrared ranges. By adding one and two resonant cavities, the PIT peak(s) was (were) achieved due to destructive interference between the side-coupled rectangle cavity and the bus waveguide. The proposed structures were demonstrated by the finite element method. The simulation results showed that for three rectangle resonators system, not only can we manipulate each single PIT window, but also the double PIT windows simultaneously by adjusting one of the geometrical parameters of the system; for four rectangle resonators system, by changing the widths, the lengths and the refractive index of three cavities simultaneously, we would realize treble PIT peaks and induce an off-to-on PIT optical response. Our novel plasmonic structures and the findings pave the way for new design and engineering of highly integrated optical circuit such as nanoscale optical switching, nanosensor and wavelength-selecting nanostructure.

a Schema for Extraction of Indoor Pedestrian Navigation Grid Network from Floor Plans

NASA Astrophysics Data System (ADS)

Niu, Lei; Song, Yiquan

2016-06-01

The requirement of the indoor navigation related tasks such emergency evacuation calls for efficient solutions for handling data sources. Therefore, the navigation grid extraction from existing floor plans draws attentions. To this, we have to thoroughly analyse the source data, such as Autocad dxf files. Then, we could establish a sounding navigation solution, which firstly complements the basic navigation rectangle boundaries, secondly subdivides these rectangles and finally generates accessible networks with these refined rectangles. Test files are introduced to validate the whole workflow and evaluate the solution performance. In conclusion, we have achieved the preliminary step of forming up accessible network from the navigation grids.

The Rectangle Target Plot: A New Approach to the Graphical Presentation of Accuracy of Systems for Self-Monitoring of Blood Glucose.

PubMed

Stephan, Peter; Schmid, Christina; Freckmann, Guido; Pleus, Stefan; Haug, Cornelia; Müller, Peter

2015-10-09

The measurement accuracy of systems for self-monitoring of blood glucose (SMBG) is usually analyzed by a method comparison in which the analysis results are displayed using difference plots or similar graphs. However, such plots become difficult to comprehend as the number of data points displayed increases. This article introduces a new approach, the rectangle target plot (RTP), which aims to provide a simplified and comprehensible visualization of accuracy data. The RTP is based on ISO 15197 accuracy evaluations of SMBG systems. Two-sided tolerance intervals for normally distributed data are calculated for absolute and relative differences at glucose concentrations <100 mg/dL and ≥100 mg/dL. These tolerance intervals provide an estimator of where a 90% proportion of results is found with a confidence level of 95%. Plotting these tolerance intervals generates a rectangle whose center indicates the systematic measurement difference of the investigated system relative to the comparison method. The size of the rectangle depends on the measurement variability. The RTP provides a means of displaying measurement accuracy data in a simple and comprehensible manner. The visualization is simplified by reducing the displayed information from typically 200 data points to just 1 rectangle. Furthermore, this allows data for several systems or several lots from 1 system to be displayed clearly and concisely in a single graph. © 2015 Diabetes Technology Society.

Thinking Deeply about Area and Perimeter

ERIC Educational Resources Information Center

Nirode, Wayne

2011-01-01

While contemplating ways to extend the author's ninth-grade honors geometry students' thinking and knowledge about area and perimeter, he discovered an interesting type of problem based on Erickson's (2001) rectangle problem, which he had been using for ten years. Erickson's original problem involves creating random rectangles with lengths and…

Is There a "Best" Rectangle?

ERIC Educational Resources Information Center

Russell, R. Alan

2011-01-01

A question posed by a teacher can often serve as an effective and engaging way to start a class. Sometimes, however, interesting questions arise from comments made by students. The investigation presented in this article arose from a student's very simple question: "Is there a perfect rectangle for folding origami?" The initial investigation was…

Preferences by Rhagoletis indifferens (Dipt., Tephritidae) and non-target flies for rectangles of various yellow colours and fluorescence

USDA-ARS?s Scientific Manuscript database

Seven sticky rectangle traps of various yellow colours and fluorescence made of cardboard were field tested against western cherry fruit fly, Rhagoletis indifferens Curran, in paired trap preference experiments in Washington state, USA. Alpha Scents (proprietary paint), Fluorescent Yellow (aerosol ...

The Divine Ratio and Golden Rectangles.

ERIC Educational Resources Information Center

Cooper, Martin

1982-01-01

The material examines aspects of Fibonacci and Lucas sequences, the generation of the Divine Ratio, and the nature of this ratio in golden rectangles, triangles, and figures made up of golden triangles. It is noted Lucas sequence is formed like Fibonacci but has one and three as the first elements. (Author/MP)

Square-lashing technique in segmental spinal instrumentation: a biomechanical study.

PubMed

Arlet, Vincent; Draxinger, Kevin; Beckman, Lorne; Steffen, Thomas

2006-07-01

Sublaminar wires have been used for many years for segmental spinal instrumentation in scoliosis surgery. More recently, stainless steel wires have been replaced by titanium cables. However, in rigid scoliotic curves, sublaminar wires or simple cables can either brake or pull out. The square-lashing technique was devised to avoid complications such as cable breakage or lamina cutout. The purpose of the study was therefore to test biomechanically the pull out and failure mode of simple sublaminar constructs versus the square-lashing technique. Individual vertebrae were subjected to pullout testing having one of two different constructs (single loop and square lashing) using either monofilament wire or multifilament cables. Four different methods of fixation were therefore tested: single wire construct, square-lashing wiring construct, single cable construct, and square-lashing cable construct. Ultimate failure load and failure mechanism were recorded. For the single wire the construct failed 12/16 times by wire breakage with an average ultimate failure load of 793 N. For the square-lashing wire the construct failed with pedicle fracture in 14/16, one bilateral lamina fracture, and one wire breakage. Ultimate failure load average was 1,239 N For the single cable the construct failed 12/16 times due to cable breakage (average force 1,162 N). 10/12 of these breakages were where the cable looped over the rod. For the square-lashing cable all of these constructs (16/16) failed by fracture of the pedicle with an average ultimate failure load of 1,388 N. The square-lashing construct had a higher pullout strength than the single loop and almost no cutting out from the lamina. The square-lashing technique with cables may therefore represent a new advance in segmental spinal instrumentation.

Restoration of motor function following spinal cord injury via optimal control of intraspinal microstimulation: toward a next generation closed-loop neural prosthesis

PubMed Central

Grahn, Peter J.; Mallory, Grant W.; Berry, B. Michael; Hachmann, Jan T.; Lobel, Darlene A.; Lujan, J. Luis

2014-01-01

Movement is planned and coordinated by the brain and carried out by contracting muscles acting on specific joints. Motor commands initiated in the brain travel through descending pathways in the spinal cord to effector motor neurons before reaching target muscles. Damage to these pathways by spinal cord injury (SCI) can result in paralysis below the injury level. However, the planning and coordination centers of the brain, as well as peripheral nerves and the muscles that they act upon, remain functional. Neuroprosthetic devices can restore motor function following SCI by direct electrical stimulation of the neuromuscular system. Unfortunately, conventional neuroprosthetic techniques are limited by a myriad of factors that include, but are not limited to, a lack of characterization of non-linear input/output system dynamics, mechanical coupling, limited number of degrees of freedom, high power consumption, large device size, and rapid onset of muscle fatigue. Wireless multi-channel closed-loop neuroprostheses that integrate command signals from the brain with sensor-based feedback from the environment and the system's state offer the possibility of increasing device performance, ultimately improving quality of life for people with SCI. In this manuscript, we review neuroprosthetic technology for improving functional restoration following SCI and describe brain-machine interfaces suitable for control of neuroprosthetic systems with multiple degrees of freedom. Additionally, we discuss novel stimulation paradigms that can improve synergy with higher planning centers and improve fatigue-resistant activation of paralyzed muscles. In the near future, integration of these technologies will provide SCI survivors with versatile closed-loop neuroprosthetic systems for restoring function to paralyzed muscles. PMID:25278830

Development and preclinical testing of a new tension-band device for the spine: the Loop system.

PubMed

Garner, Matthew D; Wolfe, Steven J; Kuslich, Stephen D

2002-10-01

Wire sutures, cerclage constructs, and tension bands have been used for many years in orthopedic surgery. Spinous process and sublaminar wires and other strands or cables are used in the spine to re-establish stability of the posterior spinal ligament complex. Rigid monofilament wires often fail due to weakening created during twisting or wrapping. Stronger metal cables do not conform well to bony surfaces. Polyethylene cables have higher fatigue strength than metal cables. The Loop cable is a pliable, radiolucent, polyethylene braid. Creep of the Loop/locking clip construct is similar to metal cable constructs using crimps. Both systems have less creep than knotted polyethylene cable constructs.

The remarkable Red Rectangle: A Stairway to Heaven?

NASA Astrophysics Data System (ADS)

2004-05-01

HD 44179 Nebula hi-res Size hi-res: 865 Kb Credits: NASA/ESA, Hans Van Winckel (Catholic University of Leuven, Belgium) and Martin Cohen (University of California) The HD 44179 nebula, known as the 'Red Rectangle.' This image, taken with the NASA/ESA Hubble Space Telescope, reveals startling new details of one of the most unusual nebulae known in our galaxy. Catalogued as HD 44179, this nebula is more commonly called the 'Red Rectangle' because of its unique shape and colour as seen with ground-based telescopes. Hubble has revealed a wealth of new features in the Red Rectangle that cannot be seen by ground-based telescopes looking through Earth’s turbulent atmosphere. Details of the Hubble study were published in the April 2004 issue of The Astronomical Journal. HD 44179 Nebula hi-res Size hi-res: 1289 Kb Credits: ESA and Vincent Icke (Leiden University, the Netherlands) Simulating the Red Rectangle The NASA/ESA Hubble Space Telescope has revealed a wealth of new features in the Red Rectangle that cannot be seen with ground-based telescopes looking through the Earth’s turbulent atmosphere. Whereas the origins of many of the features in this dying star still remain hidden or even outright mysterious, some are well explained by theorists like the Dutch scientist Vincent Icke from Leiden University in the Netherlands. In 1981 Vincent Icke and collaborators showed that a spherical gas ejection from a dying star hitting a dust torus would give rise to shocks that can produce cone-like outflows similar to the two cones seen in the Hubble image. Meteorologists produce weather forecasts by advanced calculations of temperatures, pressures, velocities and densities for the air masses in our atmosphere and, to some degree, theorists like Icke are doing exactly the same for objects in space. Whether modelling the weather in the Earth’s atmosphere or the processes in distant gaseous nebulae, scientists calculate the motion of the gas by using a complicated set of expressions known as hydrodynamic equations. Most of the matter in the Universe is in the form of gas. The weather on Earth gives rise to spectacular patterns such as thunderclouds and tornadoes in the air masses here. Likewise, the ‘weather’ in gas clouds in space, like the Red Rectangle, can be fascinating. Of the many different parameters in Vincent Icke’s calculations, only the density of the gas and the dust are observed in the Hubble image. The reflection of the gas and dust are shown in this simulated image. The colours show what one would see in scattered light - blue light scatters more than red. The ejected blobs of gas and dust look reddish, the background nebula is whiter. The three images are a time sequence with about 600 years between and show how the Red Rectangle may have been created. HD 44179 Nebula hi-res Size hi-res: 4550 Kb Credits: ESA and Digitized Sky Survey 2 Red Rectangle overview image 1 This is a ground-based view of the sky around the Red Rectangle. The image spans a square of one degree and was constructed from three images from the Digitized Sky Survey 2 taken in blue, infrared and red (shown as blue, green and red respectively). HD 44179 Nebula hi-res Size hi-res: 479 Kb Credits: ESA, ESO and Hans van Winckel (Catholic University of Leuven, Belgium) Red Rectangle overview image 2 This ground-based image was taken with the European Southern Observatory’s New Technology Telescope at La Silla Observatory. The image is constructed from three exposures through a blue filter, hydrogen-alpha filter and a red filter. This image, taken with the NASA/ESA Hubble Space Telescope, reveals startling new details of one of the most unusual nebulae known in our galaxy. Catalogued as HD 44179, this nebula is more commonly called the 'Red Rectangle' because of its unique shape and colour as seen with ground-based telescopes. Hubble has revealed a wealth of new features in the Red Rectangle that cannot be seen by ground-based telescopes looking through the Earth’s turbulent atmosphere. Details of the Hubble study were published in the April 2004 issue of The Astronomical Journal. Hans Van Winckel (Catholic University of Leuven, Belgium), the principal investigator for the Hubble observations, says: “The structure of the Red Rectangle revealed by Hubble is surprisingly complex. The features that impress me most look like the rungs of a ladder, although they are actually projections of gas cones, like a series of nested wine glasses filled to their brim with gas and seen from the side.” Hubble's sharp pictures show that the Red Rectangle is not really rectangular, but has an X-shaped structure, that astronomers interpret as arising from outflows of gas and dust from the star in the centre. The cone-like outflows are ejected from the star in two opposing directions. In addition there are straight linking features that look like the rungs on a ladder, making the Red Rectangle look similar to a spider’s web, a shape unlike that of any other known nebula in the sky. These rungs may have arisen in episodes of mass ejection from the star that occur every few hundred years and could represent a series of ‘smoke rings’, seen almost exactly edge-on from our vantage point. The star at the centre of the Red Rectangle began its life as a star similar to our Sun. It is now nearing the end of its lifetime, and is in the process of ejecting its outer layers to produce the visible nebula. The shedding of the outer layers began about 14 000 years ago, and in a few thousand years, the star will have become smaller and hotter, releasing a flood of ultraviolet light into the surrounding nebula. When this occurs the gas in the nebula will begin to fluoresce, producing a 'planetary nebula'. At the present time, however, the star is still so cool that atoms in the nebula do not glow and the surrounding dust particles are only visible as they reflect light from the central star. Exactly which molecules in the dust cloud are responsible for the striking red colour of the Rectangle is not yet clear, but it is likely that they are some kind of hydrocarbon formed in the cool outflows from the central star. Another remarkable feature of the Red Rectangle, visible only with the superb resolution of the Hubble telescope, is the dark band passing across the central star. This is the shadow of a dense disc of dust that surrounds the star and obscures it from direct view. The light we see streams out along the axis of the disc, and is scattered towards us by dust particles. Astronomers have found that the central star is actually a close pair of stars orbiting each other with a period of about 10.5 months. Interactions between these stars have probably caused the ejection of the thick dust disc that obscures our view of the binary. The disc then funnels subsequent dust and gas outflows out along its axis, forming the bizarre bi-conical structure we see as the rung of the Red Rectangle. The reasons for these fresh periodic ejections of more gas and dust remain unknown. The Red Rectangle was first discovered during a rocket flight in the early 1970s, in which astronomers were searching for strong sources of infrared radiation. This infrared source lies about 2300 light-years from Earth in the direction of the constellation Monoceros. Stars surrounded by clouds of dust are often strong infrared sources because the dust is heated by the starlight and then re-radiates long-wavelength red light. Studies of HD 44179 with ground-based telescopes revealed a rectangular shape in the dust surrounding the star at the centre, leading to the name 'Red Rectangle', coined in 1973 by astronomers Martin Cohen and Mike Merrill. This image was made from observations taken on 17-18 March 1999 with Hubble’s Wide Field Planetary Camera 2.

Finding the Area of a Circle: Didactic Explanations in School Mathematics

ERIC Educational Resources Information Center

Stacey, Kaye; Vincent, Jill

2009-01-01

Learning about the area formulas provides many opportunities for students even at the beginning of junior secondary school to experience mathematical deduction. For example, in easy cases, students can put two triangles together to make a rectangle, and so deduce that the area of a triangle is half the area of a corresponding rectangle. They can…

How Preservice Teachers Interpret and Respond to Student Errors: Ratio and Proportion in Similar Rectangles

ERIC Educational Resources Information Center

Son, Ji-Won

2013-01-01

Interpreting and responding to student thinking are central tasks of reform-minded mathematics teaching. This study examined preservice teachers' (PSTs) interpretations of and responses to a student's error(s) involving finding a missing length in similar rectangles through a teaching scenario task. Fifty-seven PSTs' responses were…

Test Scheduling for Core-Based SOCs Using Genetic Algorithm Based Heuristic Approach

NASA Astrophysics Data System (ADS)

Giri, Chandan; Sarkar, Soumojit; Chattopadhyay, Santanu

This paper presents a Genetic algorithm (GA) based solution to co-optimize test scheduling and wrapper design for core based SOCs. Core testing solutions are generated as a set of wrapper configurations, represented as rectangles with width equal to the number of TAM (Test Access Mechanism) channels and height equal to the corresponding testing time. A locally optimal best-fit heuristic based bin packing algorithm has been used to determine placement of rectangles minimizing the overall test times, whereas, GA has been utilized to generate the sequence of rectangles to be considered for placement. Experimental result on ITC'02 benchmark SOCs shows that the proposed method provides better solutions compared to the recent works reported in the literature.

Cortical control of intraspinal microstimulation: Toward a new approach for restoration of function after spinal cord injury.

PubMed

Shahdoost, Shahab; Frost, Shawn; Dunham, Caleb; DeJong, Stacey; Barbay, Scott; Nudo, Randolph; Mohseni, Pedram

2015-08-01

Approximately 6 million people in the United States are currently living with paralysis in which 23% of the cases are related to spinal cord injury (SCI). Miniaturized closed-loop neural interfaces have the potential for restoring function and mobility lost to debilitating neural injuries such as SCI by leveraging recent advancements in bioelectronics and a better understanding of the processes that underlie functional and anatomical reorganization in an injured nervous system. This paper describes our current progress toward developing a miniaturized brain-machine-spinal cord interface (BMSI) that converts in real time the neural command signals recorded from the cortical motor regions to electrical stimuli delivered to the spinal cord below the injury level. Using a combination of custom integrated circuit (IC) technology for corticospinal interfacing and field-programmable gate array (FPGA)-based technology for embedded signal processing, we demonstrate proof-of-concept of distinct muscle pattern activation via intraspinal microstimulation (ISMS) controlled in real time by intracortical neural spikes in an anesthetized laboratory rat.

Neuromodulation therapy does not influence blood flow distribution or left-ventricular dynamics during acute myocardial ischemia.

PubMed

Kingma, J G; Linderoth, B; Ardell, J L; Armour, J A; DeJongste, M J; Foreman, R D

2001-08-13

Electrical stimulation of the dorsal aspect of the upper thoracic spinal cord is used increasingly to treat patients with angina pectoris refractory to conventional therapeutic strategies. The purpose of this study was to determine whether spinal cord stimulation (SCS) in dogs affects regional myocardial blood flow and left-ventricular (LV) function before and during transient obstruction of the left anterior descending coronary artery (LAD). In anesthetized dogs, regional myocardial blood flow distribution was determined using radiolabeled microspheres and left-ventricular function was measured by impedance-derived pressure-volume loops. SCS was accomplished by stimulating the dorsal T1-T2 segments of the spinal cord using epidural bipolar electrodes at 90% of motor threshold (MT) (50 Hz, 0.2-ms duration). Effects of 5-min SCS were assessed under basal conditions and during 4-min occlusion of the LAD. SCS alone evoked no change in regional myocardial blood flow or cardiovascular indices. Transient LAD occlusion significantly diminished blood flow within ischemic, but not in non-ischemic myocardial tissue. Left ventricular pressure-volume loops were shifted rightward during LAD occlusion. Cardiac indices were altered similarly during LAD occlusion and concurrent SCS. SCS does not influence the distribution of blood flow within the non-ischemic or ischemic myocardium. Nor does it modify LV pressure-volume dynamics in the anesthetized experimental preparation.

Object-based attention in chimpanzees (Pan troglodytes).

PubMed

Ushitani, Tomokazu; Imura, Tomoko; Tomonaga, Masaki

2010-03-17

We conducted three experiments to investigate how object-based components contribute to the attentional processes of chimpanzees and to examine how such processes operate with regard to perceptually structured objects. In Experiment 1, chimpanzees responded to a spatial cueing task that required them to touch a target appearing at either end of two parallel rectangles. We compared the time involved in shifting attention (cost of attentional shift) when the locations of targets were cued and non cued. Results showed that the cost of the attentional shift within one rectangle was smaller than that beyond the object's boundary, demonstrating object-based attention in chimpanzees. The results of Experiment 2, conducted with different stimulus configurations, replicated the results of Experiment 1, supporting that object-based attention operates in chimpanzees. In Experiment 3, the cost of attentional shift within a cued but partly occluded rectangle was shorter than that within a rectangle that was cued but divided in the middle. The results suggest that the attention of chimpanzees is activated not only by an explicit object but also by fragmented patches represented as an object at a higher-order perceptual level. Chimpanzees' object-based attention may be similar to that of humans. Copyright 2010 Elsevier Ltd. All rights reserved.

How Prevalent Is Object-Based Attention?

PubMed Central

Pilz, Karin S.; Roggeveen, Alexa B.; Creighton, Sarah E.; Bennett, Patrick J.; Sekuler, Allison B.

2012-01-01

Previous research suggests that visual attention can be allocated to locations in space (space-based attention) and to objects (object-based attention). The cueing effects associated with space-based attention tend to be large and are found consistently across experiments. Object-based attention effects, however, are small and found less consistently across experiments. In three experiments we address the possibility that variability in object-based attention effects across studies reflects low incidence of such effects at the level of individual subjects. Experiment 1 measured space-based and object-based cueing effects for horizontal and vertical rectangles in 60 subjects comparing commonly used target detection and discrimination tasks. In Experiment 2 we ran another 120 subjects in a target discrimination task in which rectangle orientation varied between subjects. Using parametric statistical methods, we found object-based effects only for horizontal rectangles. Bootstrapping methods were used to measure effects in individual subjects. Significant space-based cueing effects were found in nearly all subjects in both experiments, across tasks and rectangle orientations. However, only a small number of subjects exhibited significant object-based cueing effects. Experiment 3 measured only object-based attention effects using another common paradigm and again, using bootstrapping, we found only a small number of subjects that exhibited significant object-based cueing effects. Our results show that object-based effects are more prevalent for horizontal rectangles, which is in accordance with the theory that attention may be allocated more easily along the horizontal meridian. The fact that so few individuals exhibit a significant object-based cueing effect presumably is why previous studies of this effect might have yielded inconsistent results. The results from the current study highlight the importance of considering individual subject data in addition to commonly used statistical methods. PMID:22348018

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

Shimizu, Y; Yoon, Y; Iwase, K

Purpose: We are trying to develop an image-searching technique to identify misfiled images in a picture archiving and communication system (PACS) server by using five biological fingerprints: the whole lung field, cardiac shadow, superior mediastinum, lung apex, and right lower lung. Each biological fingerprint in a chest radiograph includes distinctive anatomical structures to identify misfiled images. The whole lung field was less effective for evaluating the similarity between two images than the other biological fingerprints. This was mainly due to the variation in the positioning for chest radiographs. The purpose of this study is to develop new biological fingerprints thatmore » could reduce influence of differences in the positioning for chest radiography. Methods: Two hundred patients were selected randomly from our database (36,212 patients). These patients had two images each (current and previous images). Current images were used as the misfiled images in this study. A circumscribed rectangular area of the lung and the upper half of the rectangle were selected automatically as new biological fingerprints. These biological fingerprints were matched to all previous images in the database. The degrees of similarity between the two images were calculated for the same and different patients. The usefulness of new the biological fingerprints for automated patient recognition was examined in terms of receiver operating characteristic (ROC) analysis. Results: Area under the ROC curves (AUCs) for the circumscribed rectangle of the lung, upper half of the rectangle, and whole lung field were 0.980, 0.994, and 0.950, respectively. The new biological fingerprints showed better performance in identifying the patients correctly than the whole lung field. Conclusion: We have developed new biological fingerprints: circumscribed rectangle of the lung and upper half of the rectangle. These new biological fingerprints would be useful for automated patient identification system because they are less affected by positioning differences during imaging.« less

Superficial NK1 expressing spinal dorsal horn neurones modulate inhibitory neurotransmission mediated by spinal GABA(A) receptors.

PubMed

Rahman, Wahida; Sikandar, Shafaq; Sikander, Shafaq; Suzuki, Rie; Hunt, Stephen P; Dickenson, Anthony H

2007-06-04

Lamina 1 projection neurones which express the NK1 receptor (NK1R+) drive a descending serotonergic pathway from the brainstem that enhances spinal dorsal horn neuronal activity via the facilitatory spinal 5-HT3 receptor. Selective destruction of these cells via lumbar injection of substance P-saporin (SP-SAP) attenuates pain behaviours, including mechanical and thermal hypersensitivity, which are mirrored by deficits in the evoked responses of lamina V-VI wide dynamic range (WDR) neurones to noxious stimuli. To assess whether removing the origin of this facilitatory spino-bulbo-spinal loop results in alterations in GABAergic spinal inhibitory systems, the effects of spinal bicuculline, a selective GABA(A) receptor antagonist, on the evoked neuronal responses to electrical (Abeta-, Adelta-, C-fibre, post-discharge and Input) and mechanical (brush, prod and von Frey (vF) 8 and 26 g) stimuli were measured in SAP and SP-SAP groups. In the SAP control group, bicuculline produced a significant dose related facilitation of the electrically evoked Adelta-, C-fibre, post-discharge and input neuronal responses. The evoked mechanical (prod, vF8 g and 26 g) responses were also significantly increased. Brush evoked neuronal responses in these animals were enhanced but did not reach significance. This facilitatory effect of bicuculline, however, was lost in the SP-SAP treated group. The generation of intrinsic GABAergic transmission in the spinal cord appears dependent on NK1 bearing neurons, yet despite the loss of GABAergic inhibitory controls after SP-SAP treatment, the net effect is a decrease in spinal cord excitability. Thus activation of these cells predominantly drives facilitation.

Mir-17-3p Controls Spinal Neural Progenitor Patterning by Regulating Olig2/Irx3 Cross-repressive Loop

PubMed Central

Chen, Jun-An; Huang, Yuan-Ping; Mazzoni, Esteban O.; Tan, G. Christopher; Zavadil, Jiri; Wichterle, Hynek

2011-01-01

SUMMARY Neural patterning relies on transcriptional cross-repressive interactions that ensure unequivocal assignment of neural progenitor identity to proliferating cells. Progenitors of spinal motor neurons (pMN) and V2 interneurons (p2) are specified by a pair of cross-repressive transcription factors Olig2 and Irx3. Lineage tracing revealed that many p2 progenitors transiently express the pMN marker Olig2 during spinal cord development. Here we demonstrate that the repression of Olig2 in p2 domain is controlled by mir-17-3p microRNA-mediated silencing of Olig2 mRNA. Mice lacking all microRNAs or just the mir-17~92 cluster manifest a dorsal shift in pMN/p2 boundary and impairment in the production of V2 interneurons. Our findings suggest that microRNA-mediated repression of Olig2 mRNA plays a critical role during the patterning of ventral spinal progenitor domains by shifting the balance of cross-repressive interactions between Olig2 and Irx3 transcription factors. PMID:21338882

Rectangle Surface Coil Array in a Grid Arrangement for Resonance Imaging

DTIC Science & Technology

2016-02-13

switchable array, RF magnetic field, NQR , MRI, NMR, tuning, decoupling I. INTRODUCTION ESONANCE imaging can be accomplished using Nuclear Magnetic...Resonance (NMR) or Nuclear Quadrupole Resonance ( NQR ) techniques. REF [1] and [6] explain the differences between NMR and NQR . What NMR and NQR ...of resonance NQR frequency of 28.1MHz. The matching and tuning is explain in detail in the next section of this paper. Rectangle Surface Coil

The Role of Representation Strength of the Prime in Subliminal Visuomotor Priming.

PubMed

Wang, Yongchun; Wang, Yonghui; Liu, Peng; Di, Meilin; Gong, Yanyan; Tan, Mengge

2017-11-01

This study investigated the role of representation strength of the prime in subliminal visuomotor priming in two experiments. Prime/target compatibility (compatible and incompatible) and preposed object type (jumbled lines, strong masking; and rectangular outlines, weak masking) were manipulated in Experiment 1. A significant negative compatibility effect (NCE) was observed in the rectangle condition, whereas no compatibility effect was found in the line condition. However, when a new variable, prime duration, was introduced in Experiment 2, the NCE was reversed with an increase in the prime duration in the rectangle condition, whereas the NCE was maintained in the line condition. This result is consistent with the claim that increasing the prime duration causes the prime representation to be too strong for inhibition in the rectangle condition but strong enough to reliably trigger inhibition in the line condition. The findings demonstrated that prime representation has a causal role in subliminal visuomotor priming.

Self-Assembly of New Arene-Ruthenium Rectangles Containing Triptycene Building Block and Their Application in Fluorescent Detection of Nitro Aromatics

PubMed Central

Dubey, Abhishek; Mishra, Anurag; Min, Jin Wook; Lee, Min Hyung; Kim, Hyunuk; Stang, Peter J.; Chi, Ki-Whan

2014-01-01

A suite of two new tetraruthenium metallarectangles 5 and 6 have been obtained from [2 + 2] self-assemblies between dipyridylethynyltriptycene 2 and one of the two dinuclear arene ruthenium clips, [Ru2 (μ-η4-OO∩OO) (η6-p-cymene)2][OTf]2 ; (OO∩OO = oxalate 3; 6,11-dihydroxy-5,12-naphthacenedionato (dotq) 4; OTf = triflate). These molecular rectangles are fully characterized by 1H NMR spectroscopy, electrospray mass spectrometry. A single crystal of 6 was suitable for X-ray diffraction structural characterization. These new metallarectangles showed fluorescence behavior in solution, have been examined for emission quenching effects with various aromatic compounds, and show high quenching selectivity and sensitivity towards nitroaromatics, particularly picric acid and trinitrotoluene. Excited-state charge transfer from the rectangles to nitro aromatic substrates can be used to develop selective fluorescent sensors for nitro aromatics. PMID:26321767

Motor Control of Human Spinal Cord Disconnected from the Brain and Under External Movement.

PubMed

Mayr, Winfried; Krenn, Matthias; Dimitrijevic, Milan R

2016-01-01

Motor control after spinal cord injury is strongly depending on residual ascending and descending pathways across the lesion. The individually altered neurophysiology is in general based on still intact sublesional control loops with afferent sensory inputs linked via interneuron networks to efferent motor outputs. Partial or total loss of translesional control inputs reduces and alters the ability to perform voluntary movements and results in motor incomplete (residual voluntary control of movement functions) or motor complete (no residual voluntary control) spinal cord injury classification. Of particular importance are intact functionally silent neural structures with residual brain influence but reduced state of excitability that inhibits execution of voluntary movements. The condition is described by the term discomplete spinal cord injury. There are strong evidences that artificial afferent input, e.g., by epidural or noninvasive electrical stimulation of the lumbar posterior roots, can elevate the state of excitability and thus re-enable or augment voluntary movement functions. This modality can serve as a powerful assessment technique for monitoring details of the residual function profile after spinal cord injury, as a therapeutic tool for support of restoration of movement programs and as a neuroprosthesis component augmenting and restoring movement functions, per se or in synergy with classical neuromuscular or muscular electrical stimulation.

Deciphering the structural framework of glycine receptor anchoring by gephyrin

PubMed Central

Kim, Eun Young; Schrader, Nils; Smolinsky, Birthe; Bedet, Cécile; Vannier, Christian; Schwarz, Günter; Schindelin, Hermann

2006-01-01

Glycine is the major inhibitory neurotransmitter in the spinal cord and brain stem. Gephyrin is required to achieve a high concentration of glycine receptors (GlyRs) in the postsynaptic membrane, which is crucial for efficient glycinergic signal transduction. The interaction between gephyrin and the GlyR involves the E-domain of gephyrin and a cytoplasmic loop located between transmembrane segments three and four of the GlyR β subunit. Here, we present crystal structures of the gephyrin E-domain with and without the GlyR β-loop at 2.4 and 2.7 Å resolutions, respectively. The GlyR β-loop is bound in a symmetric ‘key and lock' fashion to each E-domain monomer in a pocket adjacent to the dimer interface. Structure-guided mutagenesis followed by in vitro binding and in vivo colocalization assays demonstrate that a hydrophobic interaction formed by Phe 330 of gephyrin and Phe 398 and Ile 400 of the GlyR β-loop is crucial for binding. PMID:16511563

A 7T Spine Array Based on Electric Dipole Transmitters

PubMed Central

Duan, Qi; Nair, Govind; Gudino, Natalia; de Zwart, Jacco A.; van Gelderen, Peter; Murphy-Boesch, Joe; Reich, Daniel S.; Duyn, Jeff H.; Merkle, Hellmut

2015-01-01

Purpose In this work the feasibility of using an array of electric dipole antennas for RF transmission in spine MRI at high field is explored. Method A 2-channel transmit array based on an electric dipole design was quantitatively optimized for 7T spine imaging and integrated with a receive array combining 8 loop coils. Using B1+ mapping, the transmit efficiency of the dipole array was compared to a design using quadrature loop pairs. The radio-frequency (RF) energy deposition for each array was measured using a home-built dielectric phantom and MR thermometry. The performance of the proposed array was qualitatively demonstrated in human studies. Results The results indicate dramatically improved transmit efficiency for the dipole design as compared to the loop excitation. Up to 76% gain was achieved within the spinal region. Conclusion For imaging of the spine, electric-dipole based transmitters provided an attractive alternative to the traditional loop-based design. Easy integration with existing receive array technology facilitates practical use at high field. PMID:26190585

Selective ablation of dorsal horn NK1 expressing cells reveals a modulation of spinal alpha2-adrenergic inhibition of dorsal horn neurones.

PubMed

Rahman, Wahida; Suzuki, Rie; Hunt, Stephen P; Dickenson, Anthony H

2008-06-01

Activity in descending systems from the brainstem modulates nociceptive transmission through the dorsal horn. Intrathecal injection of the neurotoxin saporin conjugated to SP (SP-SAP) into the lumbar spinal cord results in the selective ablation of NK(1) receptor expressing (NK(1)+ve) neurones in the superficial dorsal horn (lamina I/III). Loss of these NK(1)+ve neurones attenuates excitability of deep dorsal horn neurones due to a disruption of both intrinsic spinal circuits and a spino-bulbo-spinal loop, which activates a descending excitatory drive, mediated through spinal 5HT(3) receptors. Descending inhibitory pathways also modulate spinal activity and hence control the level of nociceptive transmission relayed to higher centres. To ascertain the spinal origins of the major descending noradrenergic inhibitory pathway we studied the effects of a selective alpha2-adrenoceptor antagonist, atipamezole, on neuronal activity in animals pre-treated with SP-SAP. Intrathecal application of atipamezole dose dependently facilitated the mechanically evoked neuronal responses of deep dorsal horn neurones to low intensity von Frey hairs (5-15 g) and noxious thermal (45-50 degrees C) evoked responses in SAP control animals indicating a physiological alpha2-adrenoceptor control. This facilitatory effect of atipamezole was lost in the SP-SAP treated group. These data suggest that activity within noradrenergic pathways have a dependence on dorsal horn NK(1)+ve cells. Further, noradrenergic descending inhibition may in part be driven by lamina I/III (NK(1)+ve) cells, and mediated via spinal alpha2-adrenoceptor activation. Since the same neuronal population drives descending facilitation and inhibition, the reduced excitability of lamina V/VI WDR neurones seen after loss of these NK(1)+ve neurones indicates a dominant role of descending facilitation.

Towards a miniaturized brain-machine-spinal cord interface (BMSI) for restoration of function after spinal cord injury.

PubMed

Shahdoost, Shahab; Frost, Shawn; Van Acker, Gustaf; DeJong, Stacey; Dunham, Caleb; Barbay, Scott; Nudo, Randolph; Mohseni, Pedram

2014-01-01

Nearly 6 million people in the United States are currently living with paralysis in which 23% of the cases are related to spinal cord injury (SCI). Miniaturized closed-loop neural interfaces have the potential for restoring function and mobility lost to debilitating neural injuries such as SCI by leveraging recent advancements in bioelectronics and a better understanding of the processes that underlie functional and anatomical reorganization in an injured nervous system. This paper describes our current progress towards developing a miniaturized brain-machine-spinal cord interface (BMSI) that is envisioned to convert in real time the neural command signals recorded from the brain to electrical stimuli delivered to the spinal cord below the injury level. Specifically, the paper reports on a corticospinal interface integrated circuit (IC) as a core building block for such a BMSI that is capable of low-noise recording of extracellular neural spikes from the cerebral cortex as well as muscle activation using intraspinal microstimulation (ISMS) in a rat with contusion injury to the thoracic spinal cord. The paper further presents results from a neurobiological study conducted in both normal and SCI rats to investigate the effect of various ISMS parameters on movement thresholds in the rat hindlimb. Coupled with proper signal-processing algorithms in the future for the transformation between the cortically recorded data and ISMS parameters, such a BMSI has the potential to facilitate functional recovery after an SCI by re-establishing corticospinal communication channels lost due to the injury.

Users Guide for Smooth-Prop: A Program for Smoothing Propeller Tip Geometry

DTIC Science & Technology

2013-10-01

Research and Development Canada – Atlantic Technical Memorandum DRDC Atlantic TM 2013-179 October 2013 c© Her Majesty the Queen in Right of Canada...a window You can magnify any region of the Blade or Plane Intersection windows by clicking and dragging with the left mouse button. A red rectangle...display. Each slider is a long rectangle containing a smaller black box: see Fig. 9. The black box is a handle that can be dragged back and forth

A fast Cauchy-Riemann solver. [differential equation solution for boundary conditions by finite difference approximation

NASA Technical Reports Server (NTRS)

Ghil, M.; Balgovind, R.

1979-01-01

The inhomogeneous Cauchy-Riemann equations in a rectangle are discretized by a finite difference approximation. Several different boundary conditions are treated explicitly, leading to algorithms which have overall second-order accuracy. All boundary conditions with either u or v prescribed along a side of the rectangle can be treated by similar methods. The algorithms presented here have nearly minimal time and storage requirements and seem suitable for development into a general-purpose direct Cauchy-Riemann solver for arbitrary boundary conditions.

Propagation of spiral waves pinned to circular and rectangular obstacles.

PubMed

Sutthiopad, Malee; Luengviriya, Jiraporn; Porjai, Porramain; Phantu, Metinee; Kanchanawarin, Jarin; Müller, Stefan C; Luengviriya, Chaiya

2015-05-01

We present an investigation of spiral waves pinned to circular and rectangular obstacles with different circumferences in both thin layers of the Belousov-Zhabotinsky reaction and numerical simulations with the Oregonator model. For circular objects, the area always increases with the circumference. In contrast, we varied the circumference of rectangles with equal areas by adjusting their width w and height h. For both obstacle forms, the propagating parameters (i.e., wavelength, wave period, and velocity of pinned spiral waves) increase with the circumference, regardless of the obstacle area. Despite these common features of the parameters, the forms of pinned spiral waves depend on the obstacle shapes. The structures of spiral waves pinned to circles as well as rectangles with the ratio w/h∼1 are similar to Archimedean spirals. When w/h increases, deformations of the spiral shapes are observed. For extremely thin rectangles with w/h≫1, these shapes can be constructed by employing semicircles with different radii which relate to the obstacle width and the core diameter of free spirals.

Gain-guided soliton fiber laser with high-quality rectangle spectrum for ultrafast time-stretch microscopy.

PubMed

Hu, Song; Yao, Jian; Liu, Meng; Luo, Ai-Ping; Luo, Zhi-Chao; Xu, Wen-Cheng

2016-05-16

The ultrafast time-stretch microscopy has been proposed to enhance the temporal resolution of a microscopy system. The optical source is a key component for ultrafast time-stretch microscopy system. Herein, we reported on the gain-guided soliton fiber laser with high-quality rectangle spectrum for ultrafast time-stretch microscopy. By virtue of the excellent characteristics of the gain-guided soliton, the output power and the 3-dB bandwidth of the stable mode-locked soliton could be up to 3 mW and 33.7 nm with a high-quality rectangle shape, respectively. With the proposed robust optical source, the ultrafast time-stretch microscopy with the 49.6 μm resolution and a scan rate of 11 MHz was achieved without the external optical amplification. The obtained results demonstrated that the gain-guided soliton fiber laser could be used as an alternative high-quality optical source for ultrafast time-stretch microscopy and will introduce some applications in fields such as biology, chemical, and optical sensing.

Heteroleptic metallosupramolecular racks, rectangles, and trigonal prisms: stoichiometry-controlled reversible interconversion.

PubMed

Neogi, Subhadip; Lorenz, Yvonne; Engeser, Marianne; Samanta, Debabrata; Schmittel, Michael

2013-06-17

A simple approach toward preparation of heteroleptic two-dimensional (2D) rectangles and three-dimensional (3D) triangular prisms is described utilizing the HETPYP (HETeroleptic PYridyl and Phenanthroline metal complexes) concept. By mixing metal-loaded linear bisphenanthrolines of varying lengths with diverse (multi)pyridine (py) ligands in a proper ratio, six different self-assembled architectures arise cleanly and spontaneously in the absence of any template. They are characterized by (1)H and DOSY NMR, ESI-FT-ICR mass spectrometry as well as by Job plots and UV-vis titrations. Density functional theory (DFT) computations provide information about each structure. A stoichiometry-controlled supramolecule-to-supramolecule interconversion based on the relative amounts of metal bisphenanthroline and bipyridine forces the rectangular assembly to reorganize to a rack architecture and back to the rectangle, as clearly supported by variable temperature and DOSY NMR as well as dynamic light scattering data. The highly dynamic nature of the assemblies represents a promising starting point for constitutional dynamic materials.

Effective Relief of Pain and Associated Symptoms With Closed-Loop Spinal Cord Stimulation System: Preliminary Results of the Avalon Study.

PubMed

Russo, Marc; Cousins, Michael J; Brooker, Charles; Taylor, Nathan; Boesel, Tillman; Sullivan, Richard; Poree, Lawrence; Shariati, Nastaran Hesam; Hanson, Erin; Parker, John

2018-01-01

Conventional spinal cord stimulation (SCS) delivers a fixed-input of energy into the dorsal column. Physiologic effects such as heartbeat, respiration, spinal cord movement, and history of stimulation can cause both the perceived intensity and recruitment of stimulation to increase or decrease, with clinical consequences. A new SCS system controls stimulation dose by measuring the recruitment of fibers in the dorsal column and by using the amplitude of the evoked compound action potentials (ECAPs) to maintain stimulation within an individualized therapeutic range. Safety and efficacy of this closed-loop system was evaluated through six-month postimplantation. Chronic pain subjects with back and/or leg pain who were successfully trialed received a permanent system (Evoke; Saluda Medical, Sydney, Australia). Ratings of pain (100-mm visual analogue scale [VAS] and Brief Pain Instrument [BPI]), quality of life (EuroQol instrument [EQ-5D-5L]), function (Oswestry Disability Index [ODI]), and sleep (Pittsburgh Sleep Quality Index [PSQI]) were collected at baseline and repeated three and six months after implantation. Fifty-one subjects underwent a trial procedure; permanent implants were placed in 36 subjects. The proportion of subjects with ≥50% relief was 92.6% (back) and 91.3% (leg) at three months, and 85.7% (back) and 82.6% (leg) at six months. The proportion with ≥80% pain relief was 70.4% (back) and 56.5% (leg) at three months, and 64.3% (back) and 60.9% (leg) at six months. Statistically significant improvements in mean BPI, EQ-5D-5L, ODI, and PSQI were also observed at both time points. The majority of subjects experienced profound pain relief at three and six months, providing preliminary evidence for the effectiveness of the closed-loop SCS system. The exact mechanism of action for these outcomes is still being explored, although one likely hypothesis holds that ECAP feedback control may minimize recruitment of Aβ nociceptors and Aδ fibers during daily use of SCS. © 2017 International Neuromodulation Society.

A Temporal and Spatial Analysis of Wave-Generated Foam Patterns in the Surf Zone

DTIC Science & Technology

2017-01-10

region, rectange B depicts the gap region, rectangle C is the plunging breaker, circle D represents a foam hole, rectangle E depict a top box...structures: The hidden skeleton of fluid flows . Phys. Today, 66, 41–47. 35 V. CONCLUSION Unique surf zone imagery, acquired from a UAV at Sand City...MacMahan, J. H., E . B . Thornton, T. P. Stanton, and A. J. H. M. Reniers, 2005: RIPEX: Observations of a rip current system. Mar. Geol., 218, 113–134

A 7T spine array based on electric dipole transmitters.

PubMed

Duan, Qi; Nair, Govind; Gudino, Natalia; de Zwart, Jacco A; van Gelderen, Peter; Murphy-Boesch, Joe; Reich, Daniel S; Duyn, Jeff H; Merkle, Hellmut

2015-10-01

The goal of this study was to explore the feasibility of using an array of electric dipole antennas for RF transmission in spine MRI at high fields. A two-channel transmit array based on an electric dipole design was quantitatively optimized for 7T spine imaging and integrated with a receive array combining eight loop coils. Using B1+ mapping, the transmit efficiency of the dipole array was compared with a design using quadrature loop pairs. The radiofrequency energy deposition for each array was measured using a home-built dielectric phantom and MR thermometry. The performance of the proposed array was qualitatively demonstrated in human studies. The results indicate dramatically improved transmit efficiency for the dipole design compared with the loop excitation. A gain of up to 76% was achieved within the spinal region. For imaging of the spine, electric dipole-based transmitters provide an attractive alternative to the traditional loop-based design. Easy integration with existing receive array technology facilitates practical use at high fields. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Introduction of clerking pro forma for surgical spinal patients at the Royal National Orthopaedic Hospital NHS Trust (London): an audit cycle.

PubMed

Pace, Valerio; Farooqi, Omar; Kennedy, James; Park, Chang; Cowan, Joseph

2018-05-01

As a tertiary referral centre of spinal surgery, the Royal National Orthopaedic Hospital (RNOH) handles hundreds of spinal cases a year, often with complex pathology and complex care needs. Despite this, issues were raised at the RNOH following lack of sufficient documentation of preoperative and postoperative clinical findings in spinal patients undergoing major surgery. This is not in keeping with guidelines provided by the Royal College of Surgeons. The authors believe that a standardised clerking pro forma for surgical spinal patients admitted to RNOH would improve the quality of care provided. Therefore, the use of a standard clerking pro forma for all surgical spinal patients could be a useful tool enabling improvements in patients care and safety in keeping with General Medical Council/National Institute for Health and Care Excellence guidelines. An audit (with closure of loop) looking into the quality of the preoperative and postoperative clinical documentation for surgical spinal patients was carried out at the RNOH in 2016 (retrospective case note audit comparing preintervention and postintervention documentation standards). Our standardised pro forma allows clinicians to best utilise their time and standardises examination to be compared in a temporal manner during the patients admission and care. It is the authors understanding that this work is a unique study looking at the quality of the admission clerking for surgical spinal patients. Evidently, there remains work to be done for the widespread utilisation of the pro forma. Early results suggest that such a pro forma can significantly improve the documentation in admission clerking with improvements in the quality of care for patients. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Helping students mathematical construction on square and rectangle’s area by using Sarong motive chess

NASA Astrophysics Data System (ADS)

Zuliana, Eka; Setyawan, Fariz; Veloo, Arsaythamby

2017-12-01

The aim of this study is developing the learning trajectory to construct students’ understanding of the concept of the area of square and rectangle by using Sarong Motive Chess. This research is a design research which is consists of three stages. The stages are preparing for the experiment, designing experiment, and making a retrospective analysis. The activities started by the activity of using sarong motive chess as the manipulative measurement unit. The Sarong motive chess helps students to understand the concept of area of square and rectangle. In the formal stage of cognitive level, students estimate the area of square and rectangle by determining the square unit at the surface area of sarong through many ways. The result of this study concludes that Sarong motive chess can be used for mathematics learning process. It helps the students to construct the concept of a square and rectangle’s area. This study produces learning trajectory to construct the concept of a square and rectangle’s area by using Sarong motive chess, especially for elementary school students.

Strength of object representation: its key role in object-based attention for determining the competition result between Gestalt and top-down objects.

PubMed

Zhao, Jingjing; Wang, Yonghui; Liu, Donglai; Zhao, Liang; Liu, Peng

2015-10-01

It was found in previous studies that two types of objects (rectangles formed according to the Gestalt principle and Chinese words formed in a top-down fashion) can both induce an object-based effect. The aim of the present study was to investigate how the strength of an object representation affects the result of the competition between these two types of objects based on research carried out by Liu, Wang and Zhou [(2011) Acta Psychologica, 138(3), 397-404]. In Experiment 1, the rectangles were filled with two different colors to increase the strength of Gestalt object representation, and we found that the object effect changed significantly for the different stimulus types. Experiment 2 used Chinese words with various familiarities to manipulate the strength of the top-down object representation. As a result, the object-based effect induced by rectangles was observed only when the Chinese word familiarity was low. These results suggest that the strength of object representation determines the result of competition between different types of objects.

Laboratory experiments on carbonaceous material as a source for the red rectangle visual emissions

NASA Technical Reports Server (NTRS)

Wdowiak, Thomas J.; Donn, Bertram; Nuth, Joseph A.; Chappelle, Emmett; Moore, Marla

1989-01-01

The authors subjected mixtures of CO, Ar, N2, H2O, and CH4 with 42 percent and 8 percent argon to an electrical discharge, froze out the reaction products at T about 20 K, and subsequently warmed the sample to room temperature. This resulted in a stable residue having broad-band fluorescence. It is suggested tht interstellar grains in the Red Rectangle/HD 44179 are coated with a residue of generally similar composition that is responsible for the broad emission feature in the 5400-7500 A spectral region.

Intraspinal microstimulation and diaphragm activation after cervical spinal cord injury

PubMed Central

Mercier, L. M.; Gonzalez-Rothi, E. J.; Streeter, K. A.; Posgai, S. S.; Poirier, A. S.; Fuller, D. D.; Reier, P. J.

2016-01-01

Intraspinal microstimulation (ISMS) using implanted electrodes can evoke locomotor movements after spinal cord injury (SCI) but has not been explored in the context of respiratory motor output. An advantage over epidural and direct muscle stimulation is the potential of ISMS to selectively stimulate components of the spinal respiratory network. The present study tested the hypothesis that medullary respiratory activity could be used to trigger midcervical ISMS and diaphragm motor unit activation in rats with cervical SCI. Studies were conducted after acute (hours) and subacute (5–21 days) C2 hemisection (C2Hx) injury in adult rats. Inspiratory bursting in the genioglossus (tongue) muscle was used to trigger a 250-ms train stimulus (100 Hz, 100–200 μA) to the ventral C4 spinal cord, targeting the phrenic motor nucleus. After both acute and subacute injury, genioglossus EMG activity effectively triggered ISMS and activated diaphragm motor units during the inspiratory phase. The ISMS paradigm also evoked short-term potentiation of spontaneous inspiratory activity in the previously paralyzed hemidiaphragm (i.e., bursting persisting beyond the stimulus period) in ∼70% of the C2Hx animals. We conclude that medullary inspiratory output can be used to trigger cervical ISMS and diaphragm activity after SCI. Further refinement of this method may enable “closed-loop-like” ISMS approaches to sustain ventilation after severe SCI. NEW & NOTEWORTHY We examined the feasibility of using intraspinal microstimulation (ISMS) of the cervical spinal cord to evoke diaphragm activity ipsilateral to acute and subacute hemisection of the upper cervical spinal cord of the rat. This proof-of-concept study demonstrated the efficacy of diaphragm activation, using an upper airway respiratory EMG signal to trigger ISMS at the level of the ipsilesional phrenic nucleus during acute and advanced postinjury intervals. PMID:27881723

Cursor Control Device Test Battery

NASA Technical Reports Server (NTRS)

Holden, Kritina; Sandor, Aniko; Pace, John; Thompson, Shelby

2013-01-01

The test battery was developed to provide a standard procedure for cursor control device evaluation. The software was built in Visual Basic and consists of nine tasks and a main menu that integrates the set-up of the tasks. The tasks can be used individually, or in a series defined in the main menu. Task 1, the Unidirectional Pointing Task, tests the speed and accuracy of clicking on targets. Two rectangles with an adjustable width and adjustable center- to-center distance are presented. The task is to click back and forth between the two rectangles. Clicks outside of the rectangles are recorded as errors. Task 2, Multidirectional Pointing Task, measures speed and accuracy of clicking on targets approached from different angles. Twenty-five numbered squares of adjustable width are arranged around an adjustable diameter circle. The task is to point and click on the numbered squares (placed on opposite sides of the circle) in consecutive order. Clicks outside of the squares are recorded as errors. Task 3, Unidirectional (horizontal) Dragging Task, is similar to dragging a file into a folder on a computer desktop. Task 3 requires dragging a square of adjustable width from one rectangle and dropping it into another. The width of each rectangle is adjustable, as well as the distance between the two rectangles. Dropping the square outside of the rectangles is recorded as an error. Task 4, Unidirectional Path Following, is similar to Task 3. The task is to drag a square through a tunnel consisting of two lines. The size of the square and the width of the tunnel are adjustable. If the square touches any of the lines, it is counted as an error and the task is restarted. Task 5, Text Selection, involves clicking on a Start button, and then moving directly to the underlined portion of the displayed text and highlighting it. The pointing distance to the text is adjustable, as well as the to-be-selected font size and the underlined character length. If the selection does not include all of the underlined characters, or includes non-underlined characters, it is recorded as an error. Task 6, Multi-size and Multi-distance Pointing, presents the participant with 24 consecutively numbered buttons of different sizes (63 to 163 pixels), and at different distances (60 to 80 pixels) from the Start button. The task is to click on the Start button, and then move directly to, and click on, each numbered target button in consecutive order. Clicks outside of the target area are errors. Task 7, Standard Interface Elements Task, involves interacting with standard interface elements as instructed in written procedures, including: drop-down menus, sliders, text boxes, radio buttons, and check boxes. Task completion time is recorded. In Task 8, a circular track is presented with a disc in it at the top. Track width and disc size are adjustable. The task is to move the disc with circular motion within the path without touching the boundaries of the track. Time and errors are recorded. Task 9 is a discrete task that allows evaluation of discrete cursor control devices that tab from target to target, such as a castle switch. The task is to follow a predefined path and to click on the yellow targets along the path.

Gamma ray evaluation of fast neutron irradiated on topaz from Sri Lanka by HPGe gamma ray spectrometry

NASA Astrophysics Data System (ADS)

Boonsook, K.; Kaewwiset, W.; Limsuwan, P.; Naemchanthara, K.

2017-09-01

The purpose of this study was to evaluate the radionuclide concentrations of London blue topaz after fast neutron irradiation. The London blue topaz was obtained from Sri Lanka which classified into dark and light colors in the shape of an oval and rectangle with small, medium and large size. The optical property and radionuclide concentrations of London blue topaz have been examine by UV-Visible spectroscopy and HPGe gamma ray spectrometry, respectively. The UV-absorption spectra of topaz was taken in the range of 300 to 800 nm at room temperature. The results showed that the absorption peak of topaz was observed with only broad peaks in the range of 550 to 700 nm and 630 nm that correlated to the O - center in hydroxyl sites which substitutes for fluorine in topaz structure. The radioactivity of dark and light colors in the shape of an oval and rectangle London blue topaz was in the range of 1.437 ± 0.014 to 21.551 ± 0.037 nCi/g (oval dark), 2.958 ± 0.031 to 6.748 ± 0.054 nCi/g (oval light) and 2.350 ± 0.014 to 43.952 ± 0.088 nCi/g (rectangle dark), 1.442 ± 0.023 to 6.748 ± 0.054 nCi/g (rectangle light), respectively. The decay rates of 46Sc, 182Ta and 54Mn isotopes created by irradiation showed that the decay time of the radioactive element depended on the size of the topaz so increased with decreasing the size of topaz. Moreover, the size of topaz also affect the absorption coefficient. This study is applied to predict time of residue dose of topaz for enhancement colorless topaz by neutron radiation treatment.

Content-aware automatic cropping for consumer photos

NASA Astrophysics Data System (ADS)

Tang, Hao; Tretter, Daniel; Lin, Qian

2013-03-01

Consumer photos are typically authored once, but need to be retargeted for reuse in various situations. These include printing a photo on different size paper, changing the size and aspect ratio of an embedded photo to accommodate the dynamic content layout of web pages or documents, adapting a large photo for browsing on small displays such as mobile phone screens, and improving the aesthetic quality of a photo that was badly composed at the capture time. In this paper, we propose a novel, effective, and comprehensive content-aware automatic cropping (hereafter referred to as "autocrop") method for consumer photos to achieve the above purposes. Our autocrop method combines the state-of-the-art context-aware saliency detection algorithm, which aims to infer the likely intent of the photographer, and the "branch-and-bound" efficient subwindow search optimization technique, which seeks to locate the globally optimal cropping rectangle in a fast manner. Unlike most current autocrop methods, which can only crop a photo into an arbitrary rectangle, our autocrop method can automatically crop a photo into either a rectangle of arbitrary dimensions or a rectangle of the desired aspect ratio specified by the user. The aggressiveness of the cropping operation may be either automatically determined by the method or manually indicated by the user with ease. In addition, our autocrop method is extended to support the cropping of a photo into non-rectangular shapes such as polygons of any number of sides. It may also be potentially extended to return multiple cropping suggestions, which will enable the creation of new photos to enrich the original photo collections. Our experimental results show that the proposed autocrop method in this paper can generate high-quality crops for consumer photos of various types.

Collinear cluster tri-partition - the brightest observations and their treating

NASA Astrophysics Data System (ADS)

Pyatkov, Yu V.; Kamanin, D. V.; Lavrova, J. E.; Mkaza, N.; Malaza, V.; Strekalovsky, A. O.

2017-06-01

Careful studies of the fission fragments mass correlation distributions let us to reveal specific linear structures in the region of a big missing mass. It became possible due to applying of effective cleaning of this region from the background linked with scattered fragments. One of the most pronounced structure looks like a rectangle bounded by the magic nuclei. The fission events aggregated in the rectangle show a very low total kinetic energy. We propose possible scenario of forming and decay of the multi-cluster prescission configuration decisive for the experimental findings. This approach is valid as well for treating of another rare decay modes discovered in the past.

Small bowel entrapment and ureteropelvic junction disruption associated with L3 Chance fracture-dislocation.

PubMed

Pesenti, Sebastien; Blondel, Benjamin; Faure, Alice; Peltier, Emilie; Launay, Franck; Jouve, Jean-Luc

2016-09-16

Paediatric Chance fracture are rare lesions but often associated with abdominal injuries. We herein present the case of a seven years old patient who sustained an entrapment of small bowel and an ureteropelvic disruption associated with a Chance fracture and spine dislocation following a traffic accident. Initial X-rays and computed tomographic (CT) scan showed a Chance fracture with dislocation of L3 vertebra, with an incarceration of a small bowel loop in the spinal canal and a complete section of the left lumbar ureter. Paraplegia was noticed on the initial neurological examination. A posterior L2-L4 osteosynthesis was performed firstly. In a second time she underwent a sus umbilical laparotomy to release the incarcerated jejunum loop in the spinal canal. An end-to-end anastomosis was performed on a JJ probe to suture the left injured ureter. One month after the traumatism, she started to complain of severe headaches related to a leakage of cerebrospinalis fluid. Three months after the traumatism there was a clear regression of the leakage. One year after the trauma, an anterior intervertebral fusion was done. At final follow-up, no neurologic recovery was noticed. In case of Chance fracture, all physicians should think about abdominal injuries even if the patient is asymptomatic. Initial abdominal CT scan and magnetic resonance imaging provide in such case crucial info for management of the spine and the associated lesions.

Real-time control of walking using recordings from dorsal root ganglia.

PubMed

Holinski, B J; Everaert, D G; Mushahwar, V K; Stein, R B

2013-10-01

The goal of this study was to decode sensory information from the dorsal root ganglia (DRG) in real time, and to use this information to adapt the control of unilateral stepping with a state-based control algorithm consisting of both feed-forward and feedback components. In five anesthetized cats, hind limb stepping on a walkway or treadmill was produced by patterned electrical stimulation of the spinal cord through implanted microwire arrays, while neuronal activity was recorded from the DRG. Different parameters, including distance and tilt of the vector between hip and limb endpoint, integrated gyroscope and ground reaction force were modelled from recorded neural firing rates. These models were then used for closed-loop feedback. Overall, firing-rate-based predictions of kinematic sensors (limb endpoint, integrated gyroscope) were the most accurate with variance accounted for >60% on average. Force prediction had the lowest prediction accuracy (48 ± 13%) but produced the greatest percentage of successful rule activations (96.3%) for stepping under closed-loop feedback control. The prediction of all sensor modalities degraded over time, with the exception of tilt. Sensory feedback from moving limbs would be a desirable component of any neuroprosthetic device designed to restore walking in people after a spinal cord injury. This study provides a proof-of-principle that real-time feedback from the DRG is possible and could form part of a fully implantable neuroprosthetic device with further development.

Neuroprosthetic technology for individuals with spinal cord injury

PubMed Central

Collinger, Jennifer L.; Foldes, Stephen; Bruns, Tim M.; Wodlinger, Brian; Gaunt, Robert; Weber, Douglas J.

2013-01-01

Context Spinal cord injury (SCI) results in a loss of function and sensation below the level of the lesion. Neuroprosthetic technology has been developed to help restore motor and autonomic functions as well as to provide sensory feedback. Findings This paper provides an overview of neuroprosthetic technology that aims to address the priorities for functional restoration as defined by individuals with SCI. We describe neuroprostheses that are in various stages of preclinical development, clinical testing, and commercialization including functional electrical stimulators, epidural and intraspinal microstimulation, bladder neuroprosthesis, and cortical stimulation for restoring sensation. We also discuss neural recording technologies that may provide command or feedback signals for neuroprosthetic devices. Conclusion/clinical relevance Neuroprostheses have begun to address the priorities of individuals with SCI, although there remains room for improvement. In addition to continued technological improvements, closing the loop between the technology and the user may help provide intuitive device control with high levels of performance. PMID:23820142

Tailoring polarization of electromagnetically induced transparency based on non-centrosymmetric metasurfaces

NASA Astrophysics Data System (ADS)

Li, Hai-ming; Xue, Feng

2017-09-01

In this manuscript, tailoring polarization of analogy of electromagnetically induced transparency (EIT-like) based on non-centrosymmetric metasurfaces has been numerically and experimentally demonstrated. The EIT-like metamaterial is composed of a rectangle ring and two cut wires. The rectangle ring and the cut wire are chosen as the bright mode and the quasi-dark mode, respectively. Under the incident electromagnetic wave excitation, a polarization insensitive EIT-like transmission window can be observed at specific polarization angles. Within the transmission window, the phase steeply changes, which leads to the large group index. Tailoring polarization of EIT-like metamaterial with large group index at specific polarization angles may have potential application in slow light devices.

Computer access security code system

NASA Technical Reports Server (NTRS)

Collins, Earl R., Jr. (Inventor)

1990-01-01

A security code system for controlling access to computer and computer-controlled entry situations comprises a plurality of subsets of alpha-numeric characters disposed in random order in matrices of at least two dimensions forming theoretical rectangles, cubes, etc., such that when access is desired, at least one pair of previously unused character subsets not found in the same row or column of the matrix is chosen at random and transmitted by the computer. The proper response to gain access is transmittal of subsets which complete the rectangle, and/or a parallelepiped whose opposite corners were defined by first groups of code. Once used, subsets are not used again to absolutely defeat unauthorized access by eavesdropping, and the like.

Strength of surgical wire fixation. A laboratory study.

PubMed

Guadagni, J R; Drummond, D S

1986-08-01

Because of the frequent use of stainless steel wire in spinal surgery and to augment fracture fixation, several methods of securing wire fixation were tested in the laboratory to determine the relative strength of fixation. Any method of fixation stronger than the yield strength of the wire is sufficient. Square knots, knot twists, symmetric twists, and the AO loop-tuck techniques afforded acceptable resistance against tension loads, but the wire wrap and AO loop technique were unacceptable. The double symmetric twist, which is frequently used for tension banding, was barely acceptable. The symmetric twist technique was the most practical because it is strong enough, efficient in maintaining tension applied during fixation, and least likely to cause damage to the wire. To optimize the fixation strength of the symmetrical twist, at least two twists are required at a reasonably tight pitch.

Three-dimensional finite element analysis on canine teeth distalization by different accessories of bracket-free invisible orthodontics technology

NASA Astrophysics Data System (ADS)

Xu, Nuo; Lei, Xue; Yang, Xiaoli; Li, Xinhui; Ge, Zhenlin

2018-04-01

Objective: to compare canine tooth stress distribution condition during maxillary canine tooth distalization by different accessories of bracket-free invisible orthodontics technology after removal of maxillary first premolar, and provide basis for clinical design of invisible orthodontics technology. Method: CBCT scanning image of a patient with individual normal occlusion was adopted, Mimics, Geomagic and ProlE software were used for establishing three-dimensional models of maxilla, maxillary dentition, parodontium, invisible orthodontics appliance and accessories, ANSYS WORKBENCH was utilized as finite element analysis tools for analyzing stress distribution and movement pattern of canine tooth and parodontium when canine tooth was equipped with power arm and vertical rectangle accessory. Meanwhile, canine tooth none-accessory design group was regarded as a control. Result: teeth had even bistal surface stress distribution in the power arm group; stress was concentrated on distal tooth neck, and the stress was gradually deviated to mesial-labial side and distal lingual side in vertical rectangle group and none-accessory group. Conclusion: teeth tend to move as a whole in the Power arm group, vertical rectangle group has lower tooth gradient compared with the none-accessory group, teeth are inclined for movement in the none-accessory group, and canine teeth tend to rotate to the distal lingual side.

A rectangle-type linear ultrasonic motor using longitudinal vibration transducers with four driving feet.

PubMed

Liu, Yingxiang; Chen, Weishan; Liu, Junkao; Shi, Shengjun

2013-04-01

To make full use of the vibrational energy of a longitudinal transducer, a rectangle-type linear ultrasonic motor with four driving feet is proposed in this paper. This new motor consists of four longitudinal vibration transducers which are arranged in a rectangle and form an enclosed construction. Lead zirconate titanate ceramics are embedded into the middle of the transducer and fastened by a wedge-caulking mechanism. Each transducer includes an exponentially shaped horn located on each end. The horns of the vertical transducers intersect at the base of the horizontal transducers' horns; the tip ends of the horizontal transducers' horns are used as the driving feet. Longitudinal vibrations are superimposed in the motor and generate elliptical movements at the tip ends of the horns. The working principle of the proposed motor is analyzed. The resonance frequencies of two working modes are tuned to be close to each other by adjusting the structural parameters. Transient analysis is developed to gain the vibration characteristics of the motor. A prototype motor is fabricated and measured. The vibration test results verify the feasibility of the proposed design. Typical output of the prototype is a no-load speed of 928 mm/s and maximum thrust force of 60 N at a voltage of 200 Vrms.

Bio-Inspired Controller on an FPGA Applied to Closed-Loop Diaphragmatic Stimulation

PubMed Central

Zbrzeski, Adeline; Bornat, Yannick; Hillen, Brian; Siu, Ricardo; Abbas, James; Jung, Ranu; Renaud, Sylvie

2016-01-01

Cervical spinal cord injury can disrupt connections between the brain respiratory network and the respiratory muscles which can lead to partial or complete loss of ventilatory control and require ventilatory assistance. Unlike current open-loop technology, a closed-loop diaphragmatic pacing system could overcome the drawbacks of manual titration as well as respond to changing ventilation requirements. We present an original bio-inspired assistive technology for real-time ventilation assistance, implemented in a digital configurable Field Programmable Gate Array (FPGA). The bio-inspired controller, which is a spiking neural network (SNN) inspired by the medullary respiratory network, is as robust as a classic controller while having a flexible, low-power and low-cost hardware design. The system was simulated in MATLAB with FPGA-specific constraints and tested with a computational model of rat breathing; the model reproduced experimentally collected respiratory data in eupneic animals. The open-loop version of the bio-inspired controller was implemented on the FPGA. Electrical test bench characterizations confirmed the system functionality. Open and closed-loop paradigm simulations were simulated to test the FPGA system real-time behavior using the rat computational model. The closed-loop system monitors breathing and changes in respiratory demands to drive diaphragmatic stimulation. The simulated results inform future acute animal experiments and constitute the first step toward the development of a neuromorphic, adaptive, compact, low-power, implantable device. The bio-inspired hardware design optimizes the FPGA resource and time costs while harnessing the computational power of spike-based neuromorphic hardware. Its real-time feature makes it suitable for in vivo applications. PMID:27378844

Real-time control of walking using recordings from dorsal root ganglia

NASA Astrophysics Data System (ADS)

Holinski, B. J.; Everaert, D. G.; Mushahwar, V. K.; Stein, R. B.

2013-10-01

Objective. The goal of this study was to decode sensory information from the dorsal root ganglia (DRG) in real time, and to use this information to adapt the control of unilateral stepping with a state-based control algorithm consisting of both feed-forward and feedback components. Approach. In five anesthetized cats, hind limb stepping on a walkway or treadmill was produced by patterned electrical stimulation of the spinal cord through implanted microwire arrays, while neuronal activity was recorded from the DRG. Different parameters, including distance and tilt of the vector between hip and limb endpoint, integrated gyroscope and ground reaction force were modelled from recorded neural firing rates. These models were then used for closed-loop feedback. Main results. Overall, firing-rate-based predictions of kinematic sensors (limb endpoint, integrated gyroscope) were the most accurate with variance accounted for >60% on average. Force prediction had the lowest prediction accuracy (48 ± 13%) but produced the greatest percentage of successful rule activations (96.3%) for stepping under closed-loop feedback control. The prediction of all sensor modalities degraded over time, with the exception of tilt. Significance. Sensory feedback from moving limbs would be a desirable component of any neuroprosthetic device designed to restore walking in people after a spinal cord injury. This study provides a proof-of-principle that real-time feedback from the DRG is possible and could form part of a fully implantable neuroprosthetic device with further development.

Real-time control of walking using recordings from dorsal root ganglia

PubMed Central

Holinski, B J; Everaert, D G; Mushahwar, V K; Stein, R B

2013-01-01

Objective The goal of this study was to decode sensory information from the dorsal root ganglia (DRG) in real time, and to use this information to adapt the control of unilateral stepping with a state-based control algorithm consisting of both feed-forward and feedback components. Approach In five anesthetized cats, hind limb stepping on a walkway or treadmill was produced by patterned electrical stimulation of the spinal cord through implanted microwire arrays, while neuronal activity was recorded from the dorsal root ganglia. Different parameters, including distance and tilt of the vector between hip and limb endpoint, integrated gyroscope and ground reaction force were modeled from recorded neural firing rates. These models were then used for closed-loop feedback. Main Results Overall, firing-rate based predictions of kinematic sensors (limb endpoint, integrated gyroscope) were the most accurate with variance accounted for >60% on average. Force prediction had the lowest prediction accuracy (48±13%) but produced the greatest percentage of successful rule activations (96.3%) for stepping under closed-loop feedback control. The prediction of all sensor modalities degraded over time, with the exception of tilt. Significance Sensory feedback from moving limbs would be a desirable component of any neuroprosthetic device designed to restore walking in people after a spinal cord injury. This study provides a proof-of-principle that real-time feedback from the DRG is possible and could form part of a fully implantable neuroprosthetic device with further development. PMID:23928579

An Exact Efficiency Formula for Holographic Heat Engines

DOE PAGES

Johnson, Clifford

2016-03-31

Further consideration is given to the efficiency of a class of black hole heat engines that perform mechanical work via the pdV terms present in the First Law of extended gravitational thermodynamics. It is noted that, when the engine cycle is a rectangle with sides parallel to the (p,V) axes, the efficiency can be written simply in terms of the mass of the black hole evaluated at the corners. Since an arbitrary cycle can be approximated to any desired accuracy by a tiling of rectangles, a general geometrical algorithm for computing the efficiency of such a cycle follows. Finally, amore » simple generalization of the algorithm renders it applicable to broader classes of heat engine, even beyond the black hole context.« less

A regulatory network to segregate the identity of neuronal subtypes.

PubMed

Lee, Seunghee; Lee, Bora; Joshi, Kaumudi; Pfaff, Samuel L; Lee, Jae W; Lee, Soo-Kyung

2008-06-01

Spinal motor neurons (MNs) and V2 interneurons (V2-INs) are specified by two related LIM-complexes, MN-hexamer and V2-tetramer, respectively. Here we show how multiple parallel and complementary feedback loops are integrated to assign these two cell fates accurately. While MN-hexamer response elements (REs) are specific to MN-hexamer, V2-tetramer-REs can bind both LIM-complexes. In embryonic MNs, however, two factors cooperatively suppress the aberrant activation of V2-tetramer-REs. First, LMO4 blocks V2-tetramer assembly. Second, MN-hexamer induces a repressor, Hb9, which binds V2-tetramer-REs and suppresses their activation. V2-INs use a similar approach; V2-tetramer induces a repressor, Chx10, which binds MN-hexamer-REs and blocks their activation. Thus, our study uncovers a regulatory network to segregate related cell fates, which involves reciprocal feedforward gene regulatory loops.

In Vivo Neuromechanics: Decoding Causal Motor Neuron Behavior with Resulting Musculoskeletal Function.

PubMed

Sartori, Massimo; Yavuz, Utku Ş; Farina, Dario

2017-10-18

Human motor function emerges from the interaction between the neuromuscular and the musculoskeletal systems. Despite the knowledge of the mechanisms underlying neural and mechanical functions, there is no relevant understanding of the neuro-mechanical interplay in the neuro-musculo-skeletal system. This currently represents the major challenge to the understanding of human movement. We address this challenge by proposing a paradigm for investigating spinal motor neuron contribution to skeletal joint mechanical function in the intact human in vivo. We employ multi-muscle spatial sampling and deconvolution of high-density fiber electrical activity to decode accurate α-motor neuron discharges across five lumbosacral segments in the human spinal cord. We use complete α-motor neuron discharge series to drive forward subject-specific models of the musculoskeletal system in open-loop with no corrective feedback. We perform validation tests where mechanical moments are estimated with no knowledge of reference data over unseen conditions. This enables accurate blinded estimation of ankle function purely from motor neuron information. Remarkably, this enables observing causal associations between spinal motor neuron activity and joint moment control. We provide a new class of neural data-driven musculoskeletal modeling formulations for bridging between movement neural and mechanical levels in vivo with implications for understanding motor physiology, pathology, and recovery.

Inhibitory interneuron circuits at cortical and spinal levels are associated with individual differences in corticomuscular coherence during isometric voluntary contraction

PubMed Central

Matsuya, Ryosuke; Ushiyama, Junichi; Ushiba, Junichi

2017-01-01

Corticomuscular coherence (CMC) is an oscillatory synchronization of 15–35 Hz (β-band) between electroencephalogram (EEG) of the sensorimotor cortex and electromyogram of contracting muscles. Although we reported that the magnitude of CMC varies among individuals, the physiological mechanisms underlying this variation are still unclear. Here, we aimed to investigate the associations between CMC and intracortical inhibition (ICI) in the primary motor cortex (M1)/recurrent inhibition (RI) in the spinal cord, which probably affect oscillatory neural activities. Firstly, we quantified ICI from changes in motor-evoked potentials induced by paired-pulse transcranial magnetic stimulation in M1 during tonic isometric voluntary contraction of the first dorsal interosseous. ICI showed a significant, negative correlation with the strength of EEG β-oscillation, but not with the magnitude of CMC across individuals. Next, we quantified RI from changes in H-reflexes induced by paired-pulse electrical nerve stimulation to the posterior tibial nerve during isometric contraction of the soleus muscle. We observed a significant, positive correlation between RI and peak CMC across individuals. These results suggest that the local inhibitory interneuron networks in cortical and spinal levels are associated with the oscillatory activity in corticospinal loop. PMID:28290507

Decoding intravesical pressure from local field potentials in rat lumbosacral spinal cord

NASA Astrophysics Data System (ADS)

Im, Changkyun; Park, Hae Yong; Koh, Chin Su; Ryu, Sang Baek; Seo, In Seok; Kim, Yong Jung; Kim, Kyung Hwan; Shin, Hyung-Cheul

2016-10-01

Chronic monitoring of intravesical pressure is required to detect the onset of intravesical hypertension and the progression of a more severe condition. Recent reports demonstrate the bladder state can be monitored from the spiking activity of the dorsal root ganglia or lumbosacral spinal cord. However, one of the most serious challenges for these methods is the difficulty of sustained spike signal acquisition due to the high-electrode-location-sensitivity of spikes or neuro-degeneration. Alternatively, it has been demonstrated that local field potential recordings are less affected by encapsulation reactions or electrode location changes. Here, we hypothesized that local field potential (LFP) from the lumbosacral dorsal horn may provide information concerning the intravesical pressure. LFP and spike activities were simultaneously recorded from the lumbosacral spinal cord of anesthetized rats during bladder filling. The results show that the LFP activities carry significant information about intravesical pressure along with spiking activities. Importantly, the intravesical pressure is decoded from the power in high-frequency bands (83.9-256 Hz) with a substantial performance similar to that of the spike train decoding. These findings demonstrate that high-frequency LFP activity can be an alternative intravesical pressure monitoring signal, which could lead to a proper closed loop system for urinary control.

A Role for SMN Exon 7 Splicing in the Selective Vulnerability of Motor Neurons in Spinal Muscular Atrophy

PubMed Central

Ruggiu, Matteo; McGovern, Vicki L.; Lotti, Francesco; Saieva, Luciano; Li, Darrick K.; Kariya, Shingo; Monani, Umrao R.; Burghes, Arthur H. M.

2012-01-01

Spinal muscular atrophy (SMA) is an inherited motor neuron disease caused by homozygous loss of the Survival Motor Neuron 1 (SMN1) gene. In the absence of SMN1, inefficient inclusion of exon 7 in transcripts from the nearly identical SMN2 gene results in ubiquitous SMN decrease but selective motor neuron degeneration. Here we investigated whether cell type-specific differences in the efficiency of exon 7 splicing contribute to the vulnerability of SMA motor neurons. We show that normal motor neurons express markedly lower levels of full-length SMN mRNA from SMN2 than do other cells in the spinal cord. This is due to inefficient exon 7 splicing that is intrinsic to motor neurons under normal conditions. We also find that SMN depletion in mammalian cells decreases exon 7 inclusion through a negative feedback loop affecting the splicing of its own mRNA. This mechanism is active in vivo and further decreases the efficiency of exon 7 inclusion specifically in motor neurons of severe-SMA mice. Consistent with expression of lower levels of full-length SMN, we find that SMN-dependent downstream molecular defects are exacerbated in SMA motor neurons. These findings suggest a mechanism to explain the selective vulnerability of motor neurons to loss of SMN1. PMID:22037760

Bifurcation Analysis Using Rigorous Branch and Bound Methods

NASA Technical Reports Server (NTRS)

Smith, Andrew P.; Crespo, Luis G.; Munoz, Cesar A.; Lowenberg, Mark H.

2014-01-01

For the study of nonlinear dynamic systems, it is important to locate the equilibria and bifurcations occurring within a specified computational domain. This paper proposes a new approach for solving these problems and compares it to the numerical continuation method. The new approach is based upon branch and bound and utilizes rigorous enclosure techniques to yield outer bounding sets of both the equilibrium and local bifurcation manifolds. These sets, which comprise the union of hyper-rectangles, can be made to be as tight as desired. Sufficient conditions for the existence of equilibrium and bifurcation points taking the form of algebraic inequality constraints in the state-parameter space are used to calculate their enclosures directly. The enclosures for the bifurcation sets can be computed independently of the equilibrium manifold, and are guaranteed to contain all solutions within the computational domain. A further advantage of this method is the ability to compute a near-maximally sized hyper-rectangle of high dimension centered at a fixed parameter-state point whose elements are guaranteed to exclude all bifurcation points. This hyper-rectangle, which requires a global description of the bifurcation manifold within the computational domain, cannot be obtained otherwise. A test case, based on the dynamics of a UAV subject to uncertain center of gravity location, is used to illustrate the efficacy of the method by comparing it with numerical continuation and to evaluate its computational complexity.

[Vestibular compensation studies]. [Vestibular Compensation and Morphological Studies

NASA Technical Reports Server (NTRS)

Perachio, Adrian A. (Principal Investigator)

1996-01-01

The following topics are reported: neurophysiological studies on MVN neurons during vestibular compensation; effects of spinal cord lesions on VNC neurons during compensation; a closed-loop vestibular compensation model for horizontally canal-related MVN neurons; spatiotemporal convergence in VNC neurons; contributions of irregularly firing vestibular afferents to linear and angular VOR's; application to flight studies; metabolic measures in vestibular neurons; immediate early gene expression following vestibular stimulation; morphological studies on primary afferents, central vestibular pathways, vestibular efferent projection to the vestibular end organs, and three-dimensional morphometry and imaging.

SMN deficiency in severe models of spinal muscular atrophy causes widespread intron retention and DNA damage

PubMed Central

Jangi, Mohini; Fleet, Christina; Cullen, Patrick; Gupta, Shipra V.; Mekhoubad, Shila; Chiao, Eric; Allaire, Norm; Bennett, C. Frank; Rigo, Frank; Krainer, Adrian R.; Hurt, Jessica A.; Carulli, John P.; Staropoli, John F.

2017-01-01

Spinal muscular atrophy (SMA), an autosomal recessive neuromuscular disease, is the leading monogenic cause of infant mortality. Homozygous loss of the gene survival of motor neuron 1 (SMN1) causes the selective degeneration of lower motor neurons and subsequent atrophy of proximal skeletal muscles. The SMN1 protein product, survival of motor neuron (SMN), is ubiquitously expressed and is a key factor in the assembly of the core splicing machinery. The molecular mechanisms by which disruption of the broad functions of SMN leads to neurodegeneration remain unclear. We used an antisense oligonucleotide (ASO)-based inducible mouse model of SMA to investigate the SMN-specific transcriptome changes associated with neurodegeneration. We found evidence of widespread intron retention, particularly of minor U12 introns, in the spinal cord of mice 30 d after SMA induction, which was then rescued by a therapeutic ASO. Intron retention was concomitant with a strong induction of the p53 pathway and DNA damage response, manifesting as γ-H2A.X positivity in neurons of the spinal cord and brain. Widespread intron retention and markers of the DNA damage response were also observed with SMN depletion in human SH-SY5Y neuroblastoma cells and human induced pluripotent stem cell-derived motor neurons. We also found that retained introns, high in GC content, served as substrates for the formation of transcriptional R-loops. We propose that defects in intron removal in SMA promote DNA damage in part through the formation of RNA:DNA hybrid structures, leading to motor neuron death. PMID:28270613

Automated FES for Upper Limb Rehabilitation Following Stroke and Spinal Cord Injury.

PubMed

Hodkin, Edmund F; Lei, Yuming; Humby, Jonathan; Glover, Isabel S; Choudhury, Supriyo; Kumar, Hrishikesh; Perez, Monica A; Rodgers, Helen; Jackson, Andrew

2018-05-01

Neurorehabilitation aims to induce beneficial neural plasticity in order to restore function following injury to the nervous system. There is an increasing evidence that appropriately timed functional electrical stimulation (FES) can promote associative plasticity, but the dosage is critical for lasting functional benefits. Here, we present a novel approach to closed-loop control of muscle stimulation for the rehabilitation of reach-to-grasp movements following stroke and spinal cord injury (SCI). We developed a simple, low-cost device to deliver assistive stimulation contingent on users' self-initiated movements. The device allows repeated practice with minimal input by a therapist, and is potentially suitable for home use. Pilot data demonstrate usability by people with upper limb weakness following SCI and stroke, and participant feedback was positive. Moreover, repeated training with the device over 1-2 weeks led to functional benefits on a general object manipulation assessment. Thus, automated FES delivered by this novel device may provide a promising and readily translatable therapy for upper limb rehabilitation for people with stroke and SCI.

Spinal cord stimulation alleviates motor deficits in a primate model of Parkinson disease.

PubMed

Santana, Maxwell B; Halje, Pär; Simplício, Hougelle; Richter, Ulrike; Freire, Marco Aurelio M; Petersson, Per; Fuentes, Romulo; Nicolelis, Miguel A L

2014-11-19

Although deep brain electrical stimulation can alleviate the motor symptoms of Parkinson disease (PD), just a small fraction of patients with PD can take advantage of this procedure due to its invasive nature. A significantly less invasive method--epidural spinal cord stimulation (SCS)--has been suggested as an alternative approach for symptomatic treatment of PD. However, the mechanisms underlying motor improvements through SCS are unknown. Here, we show that SCS reproducibly alleviates motor deficits in a primate model of PD. Simultaneous neuronal recordings from multiple structures of the cortico-basal ganglia-thalamic loop in parkinsonian monkeys revealed abnormal highly synchronized neuronal activity within each of these structures and excessive functional coupling among them. SCS disrupted this pathological circuit behavior in a manner that mimics the effects caused by pharmacological dopamine replacement therapy or deep brain stimulation. These results suggest that SCS should be considered as an additional treatment option for patients with PD. Copyright © 2014 Elsevier Inc. All rights reserved.

Reanimating the arm and hand with intraspinal microstimulation

NASA Astrophysics Data System (ADS)

Zimmermann, Jonas B.; Seki, Kazuhiko; Jackson, Andrew

2011-10-01

To date, there is no effective therapy for spinal cord injury, and many patients could benefit dramatically from at least partial restoration of arm and hand function. Despite a substantial body of research investigating intraspinal microstimulation (ISMS) in frogs, rodents and cats, little is known about upper-limb responses to cervical stimulation in the primate. Here, we show for the first time that long trains of ISMS delivered to the macaque spinal cord can evoke functional arm and hand movements. Complex movements involving coordinated activation of multiple muscles could be elicited from a single electrode, while just two electrodes were required for independent control of reaching and grasping. We found that the motor responses to ISMS were described by a dual exponential model that depended only on stimulation history. We demonstrate that this model can be inverted to generate stimulus trains capable of eliciting arbitrary, graded motor responses, and could be used to restore volitional movements in a closed-loop brain-machine interface.

Heilongjiang Province, China

NASA Image and Video Library

2012-12-07

Acquired by NASA Terra spacecraft, this image shows Heilongjiang, a province of China located in the northeastern part of the country. Farms are small and long skinny rectangles in shape, surrounding regularly spaced villages.

Cardinal features of involuntary force variability can arise from the closed-loop control of viscoelastic afferented muscles

PubMed Central

Laine, Christopher M.; Valero-Cuevas, Francisco J.

2018-01-01

Involuntary force variability below 15 Hz arises from, and is influenced by, many factors including descending neural drive, proprioceptive feedback, and mechanical properties of muscles and tendons. However, their potential interactions that give rise to the well-structured spectrum of involuntary force variability are not well understood due to a lack of experimental techniques. Here, we investigated the generation, modulation, and interactions among different sources of force variability using a physiologically-grounded closed-loop simulation of an afferented muscle model. The closed-loop simulation included a musculotendon model, muscle spindle, Golgi tendon organ (GTO), and a tracking controller which enabled target-guided force tracking. We demonstrate that closed-loop control of an afferented musculotendon suffices to replicate and explain surprisingly many cardinal features of involuntary force variability. Specifically, we present 1) a potential origin of low-frequency force variability associated with co-modulation of motor unit firing rates (i.e.,‘common drive’), 2) an in-depth characterization of how proprioceptive feedback pathways suffice to generate 5-12 Hz physiological tremor, and 3) evidence that modulation of those feedback pathways (i.e., presynaptic inhibition of Ia and Ib afferents, and spindle sensitivity via fusimotor drive) influence the full spectrum of force variability. These results highlight the previously underestimated importance of closed-loop neuromechanical interactions in explaining involuntary force variability during voluntary ‘isometric’ force control. Furthermore, these results provide the basis for a unifying theory that relates spinal circuitry to various manifestations of altered involuntary force variability in fatigue, aging and neurological disease. PMID:29309405

Cardinal features of involuntary force variability can arise from the closed-loop control of viscoelastic afferented muscles.

PubMed

Nagamori, Akira; Laine, Christopher M; Valero-Cuevas, Francisco J

2018-01-01

Involuntary force variability below 15 Hz arises from, and is influenced by, many factors including descending neural drive, proprioceptive feedback, and mechanical properties of muscles and tendons. However, their potential interactions that give rise to the well-structured spectrum of involuntary force variability are not well understood due to a lack of experimental techniques. Here, we investigated the generation, modulation, and interactions among different sources of force variability using a physiologically-grounded closed-loop simulation of an afferented muscle model. The closed-loop simulation included a musculotendon model, muscle spindle, Golgi tendon organ (GTO), and a tracking controller which enabled target-guided force tracking. We demonstrate that closed-loop control of an afferented musculotendon suffices to replicate and explain surprisingly many cardinal features of involuntary force variability. Specifically, we present 1) a potential origin of low-frequency force variability associated with co-modulation of motor unit firing rates (i.e.,'common drive'), 2) an in-depth characterization of how proprioceptive feedback pathways suffice to generate 5-12 Hz physiological tremor, and 3) evidence that modulation of those feedback pathways (i.e., presynaptic inhibition of Ia and Ib afferents, and spindle sensitivity via fusimotor drive) influence the full spectrum of force variability. These results highlight the previously underestimated importance of closed-loop neuromechanical interactions in explaining involuntary force variability during voluntary 'isometric' force control. Furthermore, these results provide the basis for a unifying theory that relates spinal circuitry to various manifestations of altered involuntary force variability in fatigue, aging and neurological disease.

Retaining Ring Fastener for Solar Panels

NASA Technical Reports Server (NTRS)

Wilson, A. H.

1983-01-01

Simple articulating linkage secures solar panels into supporting framework. Five element linkage collapses into W-shape for easy placement into framework, then expands to form rectangle of same dimensions as those of panel.

Keep Counting Those Boxes--There's More.

ERIC Educational Resources Information Center

Mingus, Tabitha T. Y.; Grassl, Richard M.

1998-01-01

Poses and solves several related extensions involving enumerating squares and rectangles. Describes how problem extensions can be developed and used in the classroom to motivate and challenge teachers and students to exert themselves mathematically. (ASK)

A mysterious dust clump in a disk around an evolved binary star system.

PubMed

Jura, M; Turner, J

1998-09-10

The discovery of planets in orbit around the pulsar PSR1257+12 shows that planets may form around post-main-sequence stars. Other evolved stars, such as HD44179 (an evolved star which is part of the binary system that has expelled the gas and dust that make the Red Rectangle nebula), possess gravitationally bound orbiting dust disks. It is possible that planets might form from gravitational collapse in such disks. Here we report high-angular-resolution observations at millimetre and submillimetre wavelengths of the dusk disk associated with the Red Rectangle. We find a dust clump with an estimated mass near that of Jupiter in the outer region of the disk. The clump is larger than our Solar System, and far beyond where planet formation would normally be expected, so its nature is at present unclear.

Representational momentum in older adults.

PubMed

Piotrowski, Andrea S; Jakobson, Lorna S

2011-10-01

Humans have a tendency to perceive motion even in static images that simply "imply" movement. This tendency is so strong that our memory for actions depicted in static images is distorted in the direction of implied motion - a phenomenon known as representational momentum (RM). In the present study, we created an RM display depicting a pattern of implied (clockwise) rotation of a rectangle. Young adults viewers' memory of the final position of the test rectangle was biased in the direction of continuing rotation, but older adults did not show a similar memory bias. We discuss several possible explanations for this group difference, but argue that the failure of older adults to shown an RM effect most likely reflects age-related changes in areas of the brain involved in processing real and implied motion. Copyright © 2011 Elsevier Inc. All rights reserved.

Design and Performance Evaluation on Ultra-Wideband Time-Of-Arrival 3D Tracking System

NASA Technical Reports Server (NTRS)

Ni, Jianjun; Arndt, Dickey; Ngo, Phong; Dusl, John

2012-01-01

A three-dimensional (3D) Ultra-Wideband (UWB) Time--of-Arrival (TOA) tracking system has been studied at NASA Johnson Space Center (JSC) to provide the tracking capability inside the International Space Station (ISS) modules for various applications. One of applications is to locate and report the location where crew experienced possible high level of carbon-dioxide and felt upset. In order to accurately locate those places in a multipath intensive environment like ISS modules, it requires a robust real-time location system (RTLS) which can provide the required accuracy and update rate. A 3D UWB TOA tracking system with two-way ranging has been proposed and studied. The designed system will be tested in the Wireless Habitat Testbed which simulates the ISS module environment. In this presentation, we discuss the 3D TOA tracking algorithm and the performance evaluation based on different tracking baseline configurations. The simulation results show that two configurations of the tracking baseline are feasible. With 100 picoseconds standard deviation (STD) of TOA estimates, the average tracking error 0.2392 feet (about 7 centimeters) can be achieved for configuration Twisted Rectangle while the average tracking error 0.9183 feet (about 28 centimeters) can be achieved for configuration Slightly-Twisted Top Rectangle . The tracking accuracy can be further improved with the improvement of the STD of TOA estimates. With 10 picoseconds STD of TOA estimates, the average tracking error 0.0239 feet (less than 1 centimeter) can be achieved for configuration "Twisted Rectangle".

Learning Oriented Region-based Convolutional Neural Networks for Building Detection in Satellite Remote Sensing Images

NASA Astrophysics Data System (ADS)

Chen, C.; Gong, W.; Hu, Y.; Chen, Y.; Ding, Y.

2017-05-01

The automated building detection in aerial images is a fundamental problem encountered in aerial and satellite images analysis. Recently, thanks to the advances in feature descriptions, Region-based CNN model (R-CNN) for object detection is receiving an increasing attention. Despite the excellent performance in object detection, it is problematic to directly leverage the features of R-CNN model for building detection in single aerial image. As we know, the single aerial image is in vertical view and the buildings possess significant directional feature. However, in R-CNN model, direction of the building is ignored and the detection results are represented by horizontal rectangles. For this reason, the detection results with horizontal rectangle cannot describe the building precisely. To address this problem, in this paper, we proposed a novel model with a key feature related to orientation, namely, Oriented R-CNN (OR-CNN). Our contributions are mainly in the following two aspects: 1) Introducing a new oriented layer network for detecting the rotation angle of building on the basis of the successful VGG-net R-CNN model; 2) the oriented rectangle is proposed to leverage the powerful R-CNN for remote-sensing building detection. In experiments, we establish a complete and bran-new data set for training our oriented R-CNN model and comprehensively evaluate the proposed method on a publicly available building detection data set. We demonstrate State-of-the-art results compared with the previous baseline methods.

Connections from the rat dorsal column nuclei (DCN) to the periaqueductal gray matter (PAG).

PubMed

Barbaresi, Paolo; Mensà, Emanuela

2016-08-01

Electrical stimulation of the dorsal columns (DCs; spinal cord stimulation; SCS) has been proposed to treat chronic neuropathic pain. SCS may activate a dual mechanism that would affect both the spinal cord and supraspinal levels. Stimulation of DCs or DC nuclei (DCN) in animals where neuropathic pain has been induced causes activation of brainstem centers including the periaqueductal gray (PAG), which is involved in the endogenous pain suppression system. Biotinylated dextran-amine (BDA) was iontophoretically injected into the DCN to analyze the ascending projection directed to the PAG. Separate injections into the gracile nucleus (GrN) and the cuneate nucleus (CunN) showed BDA-positive fibers terminating in different regions of the contralateral PAG. GrN-PAG afferents terminated in the caudal and middle portions of PAG-l, whereas CunN-PAG fibers terminated in the middle and rostral portions of PAG-l. Based on the DCN somatotopic map, the GrN sends information to the PAG from the contralateral hindlimb and the tail and the CunN from the contralateral forelimb, shoulder, neck and ear. This somatotopic organization is consistent with earlier electrophysiological and PAG stimulation studies. These fibers could form part of the DCs-brainstem-spinal cord loop, which may be involved in the inhibitory effects of SCS on neuropathic pain. Copyright © 2016. Published by Elsevier Ireland Ltd.

Chapter 3 innovations in the en route care of combat casualties.

PubMed

Hatzfeld, Jennifer J; Dukes, Susan; Bridges, Elizabeth

2014-01-01

The en route care environment is dynamic and requires constant innovation to ensure appropriate nursing care for combat casualties. Building on experiences in Iraq and Afghanistan, there have been tremendous innovations in the process of transporting patients, including the movement of patients with spinal injuries. Advances have also been made in pain management and noninvasive monitoring, particularly for trauma and surgical patients requiring close monitoring of their hemodynamic and perfusion status. In addition to institutionalizing these innovations, future efforts are needed to eliminate secondary insults to patients with traumatic brain injuries and technologies to provide closed-loop sedation and ventilation.

Noninvasive Intracranial Volume and Pressure Measurements Using Ultrasound (Head and Spinal)

NASA Technical Reports Server (NTRS)

Hargens, Alan R.

1999-01-01

Prevention of secondary brain injuries following head trauma can be accomplished most easily when intracranial pressure (ICP) is monitored. However, current measurement techniques are invasive and thus not practical in the combat environment. The Pulsed Phase Lock Loop device, which was developed and patented by consultants Drs. Yost and Cantrell, uses a unique, noninvasive ultrasonic phase comparison method to measure slight changes in cranial volume which occur with changes in ICP. Year two studies included whole body head-up and head-down tilting effects on intracranial compliance and pressure in six healthy volunteers.

A Game of Space Telephone

NASA Image and Video Library

2006-10-19

This image shows NASA Deep Impact spacecraft being built at Ball Aerospace & Technologies Corporation, Boulder, Colo. On July 2, 2005. The impactor S-band antenna is the rectangle-shaped object seen on the top of the impactor.

Glycine receptor mechanism illuminated by electron cryo-microscopy

PubMed Central

Du, Juan; Lü, Wei; Wu, Shenping; Cheng, Yifan; Gouaux, Eric

2015-01-01

Summary The strychnine-sensitive glycine receptor (GlyR) mediates inhibitory synaptic transmission in the spinal cord and brainstem and is linked to neurological disorders including autism and hyperekplexia. Understanding of molecular mechanisms and pharmacology of GlyRs has been hindered by a dearth of high-resolution structures. Here we report electron cryo-microscopy structures of the α1 GlyR with strychnine, glycine, or glycine/ivermectin. Strychnine arrests the receptor in an antagonist-bound, closed ion channel state, glycine stabilizes the receptor in an agonist-bound open channel state, and the glycine/ivermectin complex adopts a potentially desensitized or partially open state. Relative to the glycine-bound state, strychnine expands the agonist-binding pocket via outward movement of the C loop, promotes rearrangement of the extracellular and transmembrane domain ‘wrist’ interface, and leads to rotation of the transmembrane domain toward the pore axis, occluding the ion conduction pathway. These structures illuminate GlyR mechanism and define a rubric to interpret structures of Cys-loop receptors. PMID:26344198

Glycine receptor mechanism elucidated by electron cryo-microscopy.

PubMed

Du, Juan; Lü, Wei; Wu, Shenping; Cheng, Yifan; Gouaux, Eric

2015-10-08

The strychnine-sensitive glycine receptor (GlyR) mediates inhibitory synaptic transmission in the spinal cord and brainstem and is linked to neurological disorders, including autism and hyperekplexia. Understanding of molecular mechanisms and pharmacology of glycine receptors has been hindered by a lack of high-resolution structures. Here we report electron cryo-microscopy structures of the zebrafish α1 GlyR with strychnine, glycine, or glycine and ivermectin (glycine/ivermectin). Strychnine arrests the receptor in an antagonist-bound closed ion channel state, glycine stabilizes the receptor in an agonist-bound open channel state, and the glycine/ivermectin complex adopts a potentially desensitized or partially open state. Relative to the glycine-bound state, strychnine expands the agonist-binding pocket via outward movement of the C loop, promotes rearrangement of the extracellular and transmembrane domain 'wrist' interface, and leads to rotation of the transmembrane domain towards the pore axis, occluding the ion conduction pathway. These structures illuminate the GlyR mechanism and define a rubric to interpret structures of Cys-loop receptors.

A method for paraplegic upper-body posture estimation during standing: a pilot study for rehabilitation purposes.

PubMed

Pages, Gaël; Ramdani, Nacim; Fraisse, Philippe; Guiraud, David

2009-06-01

This paper presents a contribution for restoring standing in paraplegia while using functional electrical stimulation (FES). Movement generation induced by FES remains mostly open looped and stimulus intensities are tuned empirically. To design an efficient closed-loop control, a preliminary study has been carried out to investigate the relationship between body posture and voluntary upper body movements. A methodology is proposed to estimate body posture in the sagittal plane using force measurements exerted on supporting handles during standing. This is done by setting up constraints related to the geometric equations of a two-dimensional closed chain model and the hand-handle interactions. All measured quantities are subject to an uncertainty assumed unknown but bounded. The set membership estimation problem is solved via interval analysis. Guaranteed uncertainty bounds are computed for the estimated postures. In order to test the feasibility of our methodology, experiments were carried out with complete spinal cord injured patients.

A novel system for automated propofol sedation: hybrid sedation system (HSS).

PubMed

Zaouter, Cedrick; Taddei, Riccardo; Wehbe, Mohamad; Arbeid, Erik; Cyr, Shantale; Giunta, Francesco; Hemmerling, Thomas M

2017-04-01

Closed-loop systems for propofol have been demonstrated to be safe and reliable for general anesthesia. However, no study has been conducted using a closed-loop system specifically designed for sedation in patients under spinal anesthesia. We developed an automatic anesthesia sedation system that allows for closed-loop delivery of propofol for sedation integrating a decision support system, called the hybrid sedation system (HSS). The objective of this study is to compare this system with standard practice. One hundred fifty patients were enrolled and randomly assigned to two groups: HSS-Group (N = 75), in which propofol was administered using a closed-loop system; Control Group (N = 75), in which propofol was delivered manually. The clinical performance of the propofol sedation control is defined as efficacy to maintain bispectral index (BIS) near 65. The clinical control was called 'Excellent', 'Good', 'Poor' and 'Inadequate' with BIS values within 10 %, from 11 to 20 %, 21 to 30 %, or greater than 30 % of the BIS target of 65, respectively. The controller performance was evaluated using Varvel's parameters. Data are presented as mean ± standard deviation, groups were compared using t test or Chi square test, P < 0.05. Clinical performance of sedation showed 'Excellent' control in the HSS-group for a significantly longer period of time (49 vs. 26 % in the control group, P < 0.0001). 'Poor' and 'Inadequate' sedation was significantly shorter in the HSS Group compared to the Control Group (11 and 10 % vs. 20 and 18 %, respectively, P < 0.0001). The novel, closed-loop system for propofol sedation showed better maintenance of the target BIS value compared to manual administration.

21 CFR 166.40 - Labeling of margarine.

Code of Federal Regulations, 2014 CFR

2014-04-01

... each letter as measured by a closely fitting rectangle drawn around it, and the boldness of letters or... letters in the word “oleomargarine” or “margarine” should be equal to or exceed in prominence and boldness...

21 CFR 166.40 - Labeling of margarine.

Code of Federal Regulations, 2013 CFR

2013-04-01

... each letter as measured by a closely fitting rectangle drawn around it, and the boldness of letters or... letters in the word “oleomargarine” or “margarine” should be equal to or exceed in prominence and boldness...

21 CFR 166.40 - Labeling of margarine.

Code of Federal Regulations, 2012 CFR

2012-04-01

... each letter as measured by a closely fitting rectangle drawn around it, and the boldness of letters or... letters in the word “oleomargarine” or “margarine” should be equal to or exceed in prominence and boldness...

The Magic of Balanced Groups: Educational Applications of Magic Squares

ERIC Educational Resources Information Center

Bosse, Michael J.; Nandakumar, N. R.; Ore, Melanie L.

2007-01-01

This paper provides students with many interesting observations regarding the nature of magic squares, magic rectangles, and quasi-magic squares and provides tools for teachers to group students into ability-balanced cooperative learning groups.

The trading rectangle strategy within book models

NASA Astrophysics Data System (ADS)

Matassini, Lorenzo

2001-12-01

We introduce a model of trading where traders interact through the insertion of orders in the book. This matching mechanism is a collection of the activity of agents: They can trade at the market price or place a limit order. The latter is valid until cancelled by the trader; to this end we introduce a threshold in time after which the probability of the order to be removed is strongly increased. There is essentially no source of randomness and all the traders share a common strategy, what we call trading rectangle. Since there are no fundamentalist rules, it is not so important to identify the right moment to enter in the market. Much more effort is required to decide when to sell. The model is able to reproduce many of the complex phenomena manifested in real stock markets, including the positive correlation between bid/ask spreads and volatility.

Summary of 1978 Southeastern Virginia Urban Plume study: Aircraft results for carbon monoxide, methane, nonmethane hydrocarbons, and ozone

NASA Technical Reports Server (NTRS)

Hill, G. F.; Sachse, G. W.; Cofer, W. R., III

1981-01-01

The characteristics of the Southeastern Virginia urban plume were defined with emphasis on the photon-oxidant species. The measurement area was a rectangle, approximately 150 km by 100 km centered around Cape Charles, Virginia. Included in this area are the cities of Norfolk, Virginia Beach, Chesapeake, Newport News, and Hampton. The area is bounded on the north by Wallops Island, Virginia, and on the south by the Hampton Roads area of Tidewater Virginia. The major axis of the rectangle is oriented in the southwest-northeast direction. The data set includes aircraft measurements for carbon monoxide, methane, nonmethane hydrocarbons, and ozone. The experiment shows that CO can be successfully measured as a tracer gas and used as an index for determining localized and urban plumes. The 1978 data base provided sufficient data to assess an automated chromatograph with flame ionization detection used for measuring methane and nonmethane hydrocarbons in flight.

Stability of coefficients in the Kronecker product of a hook and a rectangle

NASA Astrophysics Data System (ADS)

Ballantine, Cristina M.; Hallahan, William T.

2016-02-01

We use recent work of Jonah Blasiak (2012 arXiv:1209.2018) to prove a stability result for the coefficients in the Kronecker product of two Schur functions: one indexed by a hook partition and one indexed by a rectangle partition. We also give nearly sharp bounds for the size of the partition starting with which the Kronecker coefficients are stable. Moreover, we show that once the bound is reached, no new Schur functions appear in the decomposition of Kronecker product. We call this property superstability. Thus, one can recover the Schur decomposition of the Kronecker product from the smallest case in which the superstability holds. The bound for superstability is sharp. Our study of this particular case of the Kronecker product is motivated by its usefulness for the understanding of the quantum Hall effect (Scharf T et al 1994 J. Phys. A: Math. Gen 27 4211-9).

Induced drag ideal efficiency factor of arbitrary lateral-vertical wing forms

NASA Technical Reports Server (NTRS)

Deyoung, J.

1980-01-01

A relatively simple equation is presented for estimating the induced drag ideal efficiency factor e for arbitrary cross sectional wing forms. This equation is based on eight basic but varied wing configurations which have exact solutions. The e function which relates the basic wings is developed statistically and is a continuous function of configuration geometry. The basic wing configurations include boxwings shaped as a rectangle, ellipse, and diamond; the V-wing; end-plate wing; 90 degree cruciform; circle dumbbell; and biplane. Example applications of the e equations are made to many wing forms such as wings with struts which form partial span rectangle dumbbell wings; bowtie, cruciform, winglet, and fan wings; and multiwings. Derivations are presented in the appendices of exact closed form solutions found of e for the V-wing and 90 degree cruciform wing and for an asymptotic solution for multiwings.

Phase transitions in a system of hard rectangles on the square lattice

NASA Astrophysics Data System (ADS)

Kundu, Joyjit; Rajesh, R.

2014-05-01

The phase diagram of a system of monodispersed hard rectangles of size m ×mk on a square lattice is numerically determined for m =2,3 and aspect ratio k =1,2,...,7. We show the existence of a disordered phase, a nematic phase with orientational order, a columnar phase with orientational and partial translational order, and a solidlike phase with sublattice order, but no orientational order. The asymptotic behavior of the phase boundaries for large k is determined using a combination of entropic arguments and a Bethe approximation. This allows us to generalize the phase diagram to larger m and k, showing that for k ≥7, the system undergoes three entropy-driven phase transitions with increasing density. The nature of the different phase transitions is established and the critical exponents for the continuous transitions are determined using finite size scaling.

REVIEW: Restoring standing capabilities with feedback control of functional neuromuscular stimulation following spinal cord injury

PubMed Central

Nataraj, Raviraj; Audu, Musa L.; Triolo, Ronald J.

2017-01-01

This paper reviews the field of feedback control for neuroprosthesis systems that restore advanced standing function to individuals with spinal cord injury. Investigations into closed-loop control of standing by functional neuromuscular stimulation (FNS) have spanned three decades. The ultimate goal for FNS standing control systems is to facilitate hands free standing and enabling the user to perform manual functions at self-selected leaning positions. However, most clinical systems for home usage currently only provide basic upright standing using preprogrammed stimulation patterns. To date, online modulation of stimulation to produce advanced standing functions such as balance against postural disturbances or the ability to assume leaning postures have been limited to simulation and laboratory investigations. While great technological advances have been made in biomechanical sensing and interfaces for neuromuscular stimulation, further progress is still required for finer motor control by FNS. Another major challenge is the development of sophisticated control schemes that produce the necessary postural adjustments, adapt against accelerating muscle fatigue, and consider volitional actions of the intact upper-body of the user. Model-based development for novel control schemes are proven and sensible approaches to prototype and test the basic operating efficacy of potentially complex and multi-faceted control systems. The major considerations for further innovation of such systems are summarized in this paper prior to describing the evolution of closed-loop FNS control of standing from previous works. Finally, necessary emerging technologies to for implementing FNS feedback control systems for standing are identified. These technological advancements include novel electrodes that more completely and selectively activate paralyzed musculature and implantable sensors and stimulation modules for flexible neuroprosthesis system deployment. PMID:28215399

Restoring standing capabilities with feedback control of functional neuromuscular stimulation following spinal cord injury.

PubMed

Nataraj, Raviraj; Audu, Musa L; Triolo, Ronald J

2017-04-01

This paper reviews the field of feedback control for neuroprosthesis systems that restore advanced standing function to individuals with spinal cord injury. Investigations into closed-loop control of standing by functional neuromuscular stimulation (FNS) have spanned three decades. The ultimate goal for FNS standing control systems is to facilitate hands free standing and enabling the user to perform manual functions at self-selected leaning positions. However, most clinical systems for home usage currently only provide basic upright standing using preprogrammed stimulation patterns. To date, online modulation of stimulation to produce advanced standing functions such as balance against postural disturbances or the ability to assume leaning postures have been limited to simulation and laboratory investigations. While great technological advances have been made in biomechanical sensing and interfaces for neuromuscular stimulation, further progress is still required for finer motor control by FNS. Another major challenge is the development of sophisticated control schemes that produce the necessary postural adjustments, adapt against accelerating muscle fatigue, and consider volitional actions of the intact upper-body of the user. Model-based development for novel control schemes are proven and sensible approaches to prototype and test the basic operating efficacy of potentially complex and multi-faceted control systems. The major considerations for further innovation of such systems are summarized in this paper prior to describing the evolution of closed-loop FNS control of standing from previous works. Finally, necessary emerging technologies to for implementing FNS feedback control systems for standing are identified. These technological advancements include novel electrodes that more completely and selectively activate paralyzed musculature and implantable sensors and stimulation modules for flexible neuroprosthesis system deployment. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Proteinase-activated receptor-4 evoked colorectal analgesia in mice: an endogenously activated feed-back loop in visceral inflammatory pain.

PubMed

Annaházi, A; Dabek, M; Gecse, K; Salvador-Cartier, C; Polizzi, A; Rosztóczy, A; Róka, R; Theodorou, V; Wittmann, T; Bueno, L; Eutamene, H

2012-01-01

Activation of proteinase-activated receptor-4 (PAR-4) from the colonic lumen has an antinociceptive effect to colorectal distension (CRD) in mice in basal conditions. We aimed to determine the functional localization of the responsible receptors and to test their role in two different hyperalgesia models. Mice received PAR-4 activating peptide (PAR-4-AP, AYPGKF-NH(2)) or vehicle intraperitoneally (IP), and abdominal EMG response to CRD was measured. The next group received PAR-4-AP intracolonically (IC) with or without 2,4,6-triaminopyrimidine, a chemical tight junction blocker, before CRD. The SCID mice were used to test the role of lymphocytes in the antihyperalgesic effect. The effects of PAR-4-AP and PAR-4-antagonist (P4pal-10) were evaluated in water avoidance stress (WAS) model and low grade 2,4,6-trinitrobenzene sulfonic acid (TNBS) colitis. Spinal Fos protein expression was visualized by immunohistochemistry. The antinociceptive effect of PAR-4-AP disappeared when was administrered IP, or with the blockade of colonic epithelial tight junctions, suggesting that PAR-4-AP needs to reach directly the nerve terminals in the colon. The CRD-induced spinal Fos overexpression was reduced by 43% by PAR-4-AP. The PAR-4-AP was antihyperalgesic in both hyperalgesia models and in mice with impaired lymphocytes. The PAR-4-antagonist significantly increased the TNBS, but not the WAS-induced colonic hyperalgesia. The antinociceptive effect of PAR-4-AP depends on its penetration to the colonic mucosa. The PAR-4 activation is endogenously involved as a feedback loop to attenuate inflammatory colonic hyperalgesia to CRD. © 2011 Blackwell Publishing Ltd.

Hyper-reactive human ventral tegmental area and aberrant mesocorticolimbic connectivity in overgeneralization of fear in generalized anxiety disorder.

PubMed

Cha, Jiook; Carlson, Joshua M; Dedora, Daniel J; Greenberg, Tsafrir; Proudfit, Greg H; Mujica-Parodi, Lilianne R

2014-04-23

The ventral tegmental area (VTA) has been primarily implicated in reward-motivated behavior. Recently, aberrant dopaminergic VTA signaling has also been implicated in anxiety-like behaviors in animal models. These findings, however, have yet to be extended to anxiety in humans. Here we hypothesized that clinical anxiety is linked to dysfunction of the mesocorticolimbic circuit during threat processing in humans; specifically, excessive or dysregulated activity of the mesocorticolimbic aversion circuit may be etiologically related to errors in distinguishing cues of threat versus safety, also known as "overgeneralization of fear." To test this, we recruited 32 females with generalized anxiety disorder and 25 age-matched healthy control females. We measured brain activity using fMRI while participants underwent a fear generalization task consisting of pseudo-randomly presented rectangles with systematically varying widths. A mid-sized rectangle served as a conditioned stimulus (CS; 50% electric shock probability) and rectangles with widths of CS ±20%, ±40%, and ±60% served as generalization stimuli (GS; never paired with electric shock). Healthy controls showed VTA reactivity proportional to the cue's perceptual similarity to CS (threat). In contrast, patients with generalized anxiety disorder showed heightened and less discriminating VTA reactivity to GS, a feature that was positively correlated with trait anxiety, as well as increased mesocortical and decreased mesohippocampal coupling. Our results suggest that the human VTA and the mesocorticolimbic system play a crucial role in threat processing, and that abnormalities in this system are implicated in maladaptive threat processing in clinical anxiety.

Targeting RNA structure in SMN2 reverses spinal muscular atrophy molecular phenotypes.

PubMed

Garcia-Lopez, Amparo; Tessaro, Francesca; Jonker, Hendrik R A; Wacker, Anna; Richter, Christian; Comte, Arnaud; Berntenis, Nikolaos; Schmucki, Roland; Hatje, Klas; Petermann, Olivier; Chiriano, Gianpaolo; Perozzo, Remo; Sciarra, Daniel; Konieczny, Piotr; Faustino, Ignacio; Fournet, Guy; Orozco, Modesto; Artero, Ruben; Metzger, Friedrich; Ebeling, Martin; Goekjian, Peter; Joseph, Benoît; Schwalbe, Harald; Scapozza, Leonardo

2018-05-23

Modification of SMN2 exon 7 (E7) splicing is a validated therapeutic strategy against spinal muscular atrophy (SMA). However, a target-based approach to identify small-molecule E7 splicing modifiers has not been attempted, which could reveal novel therapies with improved mechanistic insight. Here, we chose as a target the stem-loop RNA structure TSL2, which overlaps with the 5' splicing site of E7. A small-molecule TSL2-binding compound, homocarbonyltopsentin (PK4C9), was identified that increases E7 splicing to therapeutic levels and rescues downstream molecular alterations in SMA cells. High-resolution NMR combined with molecular modelling revealed that PK4C9 binds to pentaloop conformations of TSL2 and promotes a shift to triloop conformations that display enhanced E7 splicing. Collectively, our study validates TSL2 as a target for small-molecule drug discovery in SMA, identifies a novel mechanism of action for an E7 splicing modifier, and sets a precedent for other splicing-mediated diseases where RNA structure could be similarly targeted.

Calculated and scale model experimentally measured scattering from metallic structures in Instrument Landing System

DOT National Transportation Integrated Search

1974-03-01

Comparison is made of theoretically calculated and experimentally determined scattering from metallic tilted rectangles and vertical cylindrical scatterers. The scattering was experimentally measured in a scale model range at the Watertown Arsenal, W...

Implantable radio frequency identification sensors: wireless power and communication.

PubMed

Hutchens, Chriswell; Rennaker, Robert L; Venkataraman, Srinivasan; Ahmed, Rehan; Liao, Ran; Ibrahim, Tamer

2011-01-01

There are significant technical challenges in the development of a fully implantable wirelessly powered neural interface. Challenges include wireless transmission of sufficient power to the implanted device to ensure reliable operation for decades without replacement, minimizing tissue heating, and adequate reliable communications bandwidth. Overcoming these challenges is essential for the development of implantable closed loop system for the treatment of disorders ranging from epilepsy, incontinence, stroke and spinal cord injury. We discuss the development of the wireless power, communication and control for a Radio-Frequency Identification Sensor (RFIDS) system with targeted power range for a 700 mV, 30 to 40 uA load attained at -2 dBm.

Sequences Flanking the Gephyrin-Binding Site of GlyRβ Tune Receptor Stabilization at Synapses

PubMed Central

Grünewald, Nora; Salvatico, Charlotte; Kress, Vanessa

2018-01-01

Abstract The efficacy of synaptic transmission is determined by the number of neurotransmitter receptors at synapses. Their recruitment depends upon the availability of postsynaptic scaffolding molecules that interact with specific binding sequences of the receptor. At inhibitory synapses, gephyrin is the major scaffold protein that mediates the accumulation of heteromeric glycine receptors (GlyRs) via the cytoplasmic loop in the β-subunit (β-loop). This binding involves high- and low-affinity interactions, but the molecular mechanism of this bimodal binding and its implication in GlyR stabilization at synapses remain unknown. We have approached this question using a combination of quantitative biochemical tools and high-density single molecule tracking in cultured rat spinal cord neurons. The high-affinity binding site could be identified and was shown to rely on the formation of a 310-helix C-terminal to the β-loop core gephyrin-binding motif. This site plays a structural role in shaping the core motif and represents the major contributor to the synaptic confinement of GlyRs by gephyrin. The N-terminal flanking sequence promotes lower affinity interactions by occupying newly identified binding sites on gephyrin. Despite its low affinity, this binding site plays a modulatory role in tuning the mobility of the receptor. Together, the GlyR β-loop sequences flanking the core-binding site differentially regulate the affinity of the receptor for gephyrin and its trapping at synapses. Our experimental approach thus bridges the gap between thermodynamic aspects of receptor-scaffold interactions and functional receptor stabilization at synapses in living cells. PMID:29464196

Identification of a misfolded region in superoxide dismutase 1 that is exposed in amyotrophic lateral sclerosis.

PubMed

Rotunno, Melissa S; Auclair, Jared R; Maniatis, Stephanie; Shaffer, Scott A; Agar, Jeffrey; Bosco, Daryl A

2014-10-10

Mutations and aberrant post-translational modifications within Cu,Zn-superoxide dismutase (SOD1) cause this otherwise protective enzyme to misfold, leading to amyotrophic lateral sclerosis (ALS). The C4F6 antibody selectively binds misfolded SOD1 in spinal cord tissues from postmortem human ALS cases, as well as from an ALS-SOD1 mouse model, suggesting that the C4F6 epitope reports on a pathogenic conformation that is common to misfolded SOD1 variants. To date, the residues and structural elements that comprise this epitope have not been elucidated. Using a chemical cross-linking and mass spectrometry approach, we identified the C4F6 epitope within several ALS-linked SOD1 variants, as well as an oxidized form of WT SOD1, supporting the notion that a similar misfolded conformation is shared among pathological SOD1 proteins. Exposure of the C4F6 epitope was modulated by the SOD1 electrostatic (loop VII) and zinc binding (loop IV) loops and correlated with SOD1-induced toxicity in a primary microglia activation assay. Site-directed mutagenesis revealed Asp(92) and Asp(96) as key residues within the C4F6 epitope required for the SOD1-C4F6 binding interaction. We propose that stabilizing the functional loops within SOD1 and/or obscuring the C4F6 epitope are viable therapeutic strategies for treating SOD1-mediated ALS. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

The influence of object similarity and orientation on object-based cueing.

PubMed

Hein, Elisabeth; Blaschke, Stefan; Rolke, Bettina

2017-01-01

Responses to targets that appear at a noncued position within the same object (invalid-same) compared to a noncued position at an equidistant different object (invalid-different) tend to be faster and more accurate. These cueing effects have been taken as evidence that visual attention can be object based (Egly, Driver, & Rafal, Journal of Experimental Psychology: General, 123, 161-177, 1994). Recent findings, however, have shown that the object-based cueing effect is influenced by object orientation, suggesting that the cueing effect might be due to a more general facilitation of attentional shifts across the horizontal meridian (Al-Janabi & Greenberg, Attention, Perception, & Psychophysics, 1-17, 2016; Pilz, Roggeveen, Creighton, Bennet, & Sekuler, PLOS ONE, 7, e30693, 2012). The aim of this study was to investigate whether the object-based cueing effect is influenced by object similarity and orientation. According to the object-based attention account, objects that are less similar to each other should elicit stronger object-based cueing effects independent of object orientation, whereas the horizontal meridian theory would not predict any effect of object similarity. We manipulated object similarity by using a color (Exp. 1, Exp. 2A) or shape change (Exp. 2B) to distinguish two rectangles in a variation of the classic two-rectangle paradigm (Egly et al., 1994). We found that the object-based cueing effects were influenced by the orientation of the rectangles and strengthened by object dissimilarity. We suggest that object-based cueing effects are strongly affected by the facilitation of attention along the horizontal meridian, but that they also have an object-based attentional component, which is revealed when the dissimilarity between the presented objects is accentuated.

Development of a Catalytic Combustor for Aircraft Gas Turbine Engines.

DTIC Science & Technology

1976-09-22

80 VI. DESIGN OF 7.6 CI CIANETE COMBUSTORS . . . . . . . . . . . 86 1. Design and Fabrication of CombusLors for Large Scale T est in...obtained for this program included round holes of different diameters, squares, rectangles, triangles, and other more complex hollow configurations

Nanoscale imaging of magnetization reversal driven by spin-orbit torque

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

Gilbert, Ian; Chen, P. J.; Gopman, Daniel B.

We use scanning electron microscopy with polarization analysis to image deterministic, spin-orbit torque-driven magnetization reversal of in-plane magnetized CoFeB rectangles in zero applied magnetic field. The spin-orbit torque is generated by running a current through heavy metal microstrips, either Pt or Ta, upon which the CoFeB rectangles are deposited. We image the CoFeB magnetization before and after a current pulse to see the effect of spin-orbit torque on the magnetic nanostructure. The observed changes in magnetic structure can be complex, deviating significantly from a simple macrospin approximation, especially in larger elements. Overall, however, the directions of the magnetization reversal inmore » the Pt and Ta devices are opposite, consistent with the opposite signs of the spin Hall angles of these materials. Lastly, our results elucidate the effects of current density, geometry, and magnetic domain structure on magnetization switching driven by spin-orbit torque.« less

The square lattice Ising model on the rectangle II: finite-size scaling limit

NASA Astrophysics Data System (ADS)

Hucht, Alfred

2017-06-01

Based on the results published recently (Hucht 2017 J. Phys. A: Math. Theor. 50 065201), the universal finite-size contributions to the free energy of the square lattice Ising model on the L× M rectangle, with open boundary conditions in both directions, are calculated exactly in the finite-size scaling limit L, M\\to∞ , T\\to Tc , with fixed temperature scaling variable x\\propto(T/Tc-1)M and fixed aspect ratio ρ\\propto L/M . We derive exponentially fast converging series for the related Casimir potential and Casimir force scaling functions. At the critical point T=Tc we confirm predictions from conformal field theory (Cardy and Peschel 1988 Nucl. Phys. B 300 377, Kleban and Vassileva 1991 J. Phys. A: Math. Gen. 24 3407). The presence of corners and the related corner free energy has dramatic impact on the Casimir scaling functions and leads to a logarithmic divergence of the Casimir potential scaling function at criticality.

The impact of mathematical models of teaching materials on square and rectangle concepts to improve students' mathematical connection ability and mathematical disposition in middle school

NASA Astrophysics Data System (ADS)

Afrizal, Irfan Mufti; Dachlan, Jarnawi Afghani

2017-05-01

The aim of this study was to determine design of mathematical models of teaching materials to improve students' mathematical connection ability and mathematical disposition in middle school through experimental studies. The design in this study was quasi-experimental with non-equivalent control group type. This study consisted of two phases, the first phase was identify students' learning obstacle on square and rectangle concepts to obtain the appropriate design of teaching materials, beside that there were internalization of the values or characters expected to appear on students through the teaching materials. Second phase was experiments on the effectiveness and efficiency of mathematical models of teaching materials to improve students' mathematical connection ability and mathematical disposition. The result of this study are 1) Students' learning obstacle that have identified was categorized as an epistemological obstacle. 2) The improvement of students' mathematical connection ability and mathematical disposition who used mathematical teaching materials is better than the students who used conventional learning.

An analytical method for the inverse Cauchy problem of Lame equation in a rectangle

NASA Astrophysics Data System (ADS)

Grigor’ev, Yu

2018-04-01

In this paper, we present an analytical computational method for the inverse Cauchy problem of Lame equation in the elasticity theory. A rectangular domain is frequently used in engineering structures and we only consider the analytical solution in a two-dimensional rectangle, wherein a missing boundary condition is recovered from the full measurement of stresses and displacements on an accessible boundary. The essence of the method consists in solving three independent Cauchy problems for the Laplace and Poisson equations. For each of them, the Fourier series is used to formulate a first-kind Fredholm integral equation for the unknown function of data. Then, we use a Lavrentiev regularization method, and the termwise separable property of kernel function allows us to obtain a closed-form regularized solution. As a result, for the displacement components, we obtain solutions in the form of a sum of series with three regularization parameters. The uniform convergence and error estimation of the regularized solutions are proved.

Development of new force sensor using super-multilayer alternating laminated film comprising piezoelectric poly(l-lactic acid) and poly(d-lactic acid) films in the shape of a rectangle with round corners

NASA Astrophysics Data System (ADS)

Tajitsu, Yoshiro; Adachi, Yu; Nakatsuji, Takahiro; Tamura, Masataka; Sakamoto, Kousei; Tone, Takaaki; Imoto, Kenji; Kato, Atsuko; Yoshida, Testuo

2017-10-01

A new super-multilayer alternating laminated film in the shape of a rectangle with round corners has been developed. The super-multilayer film, which comprised piezoelectric poly(l-lactic acid) (PLLA) and poly(d-lactic acid) (PDLA) films, was wound with the number of turns on the order of from 100 to 1000 to form piezoelectric rolls. These piezoelectric rolls could generate an induced voltage of more than 95% of the initial voltage for over 10 s when a constant load was applied. The desired duration and magnitude of the piezoelectric response voltage were realized by adjusting the number of turns of the piezoelectric rolls. Similarly to many other conventional piezoelectrics, the piezoelectric rolls enable instantaneous load-dependent voltage generation and attenuation. The piezoelectric rolls are also lighter than conventional piezoelectric ceramics and can be used as a novel pressure sensor.

Programming of a Mn-coordinated 4-4‧-biphenyl dicarboxylic acid nanosystem on Au(1 1 1) and investigation of the non-covalent binding of C60 molecules

NASA Astrophysics Data System (ADS)

Zhang, Yan-Feng; Zhu, Na; Komeda, T.

The fabrication of Mn-based coordination networks on a Au(1 1 1) substrate with 4-4 '-biphenyl dicarboxylic acid (BDA) as the linker molecule was investigated by scanning tunneling microscopy. Intriguing structures of ladder and rectangular-shaped networks were obtained by controlling the ratios of deposited amount of BDA molecules and Mn atoms. These structures are well explained by models in which BDA molecules occupy the perimeter of the rectangles and a pair of two Mn atoms are placed at the lattice points. For the rectangular structure, further two phases of a rectangular and a square networks were identified in which the paired Mn atoms were directing an identical direction and 90° rotated in an alternate manner, respectively. In addition, it was revealed that the open space surrounded by rectangle BDA molecules could capture a dimer of C60 molecules which were deposited on the Mn-based BDA networks.

Nanoscale imaging of magnetization reversal driven by spin-orbit torque

DOE PAGES

Gilbert, Ian; Chen, P. J.; Gopman, Daniel B.; ...

2016-09-23

We use scanning electron microscopy with polarization analysis to image deterministic, spin-orbit torque-driven magnetization reversal of in-plane magnetized CoFeB rectangles in zero applied magnetic field. The spin-orbit torque is generated by running a current through heavy metal microstrips, either Pt or Ta, upon which the CoFeB rectangles are deposited. We image the CoFeB magnetization before and after a current pulse to see the effect of spin-orbit torque on the magnetic nanostructure. The observed changes in magnetic structure can be complex, deviating significantly from a simple macrospin approximation, especially in larger elements. Overall, however, the directions of the magnetization reversal inmore » the Pt and Ta devices are opposite, consistent with the opposite signs of the spin Hall angles of these materials. Lastly, our results elucidate the effects of current density, geometry, and magnetic domain structure on magnetization switching driven by spin-orbit torque.« less

Where Kepler Sees

NASA Image and Video Library

2009-04-16

This star chart illustrates the large patch of sky that NASA Kepler mission will stare at for the duration of its three-and-a-half-year lifetime. The planet hunter's full field of view occupies 100 square degrees of our Milky Way galaxy, in the constellations Cygnus and Lyra. Kepler's focal plane, or the area where starlight is focused, is depicted on the star chart as a series of 42 vertical and horizontal rectangles. These rectangles represent the 95-megapixel camera's 42 charge-coupled devices, or CCDs. Scientists selected the orientation of the focal plane's field of view to avoid the region's brightest stars, which are shown as the largest black dots. Some of these bright stars can be seen falling in between the CCD modules, in areas that are not imaged. This was done so that the brightest stars will not saturate large portions of the detectors. Saturation causes signals from the bright stars to spill, or "bloom," into nearby planet-hunting territory. http://photojournal.jpl.nasa.gov/catalog/PIA11983

Linear feature detection algorithm for astronomical surveys - I. Algorithm description

NASA Astrophysics Data System (ADS)

Bektešević, Dino; Vinković, Dejan

2017-11-01

Computer vision algorithms are powerful tools in astronomical image analyses, especially when automation of object detection and extraction is required. Modern object detection algorithms in astronomy are oriented towards detection of stars and galaxies, ignoring completely the detection of existing linear features. With the emergence of wide-field sky surveys, linear features attract scientific interest as possible trails of fast flybys of near-Earth asteroids and meteors. In this work, we describe a new linear feature detection algorithm designed specifically for implementation in big data astronomy. The algorithm combines a series of algorithmic steps that first remove other objects (stars and galaxies) from the image and then enhance the line to enable more efficient line detection with the Hough algorithm. The rate of false positives is greatly reduced thanks to a step that replaces possible line segments with rectangles and then compares lines fitted to the rectangles with the lines obtained directly from the image. The speed of the algorithm and its applicability in astronomical surveys are also discussed.

The Histogram-Area Connection

ERIC Educational Resources Information Center

Gratzer, William; Carpenter, James E.

2008-01-01

This article demonstrates an alternative approach to the construction of histograms--one based on the notion of using area to represent relative density in intervals of unequal length. The resulting histograms illustrate the connection between the area of the rectangles associated with particular outcomes and the relative frequency (probability)…

Extinction-Induced Variability in Human Behavior

ERIC Educational Resources Information Center

Kinloch, Jennifer M.; Foster, T. Mary; McEwan, James S. A.

2009-01-01

Participants earned points by pressing a computer space bar (Experiment 1) or forming rectangles on the screen with the mouse (Experiment 2) under differential-reinforcement-of-low-rate schedules, followed by extinction. Variability in interresponse time (the contingent dimension) increased during extinction, as for Morgan and Lee (1996);…

Favourite Gems

ERIC Educational Resources Information Center

Barnes, John

2011-01-01

Mathematics is full of surprises and beauty. In this article, the author discusses three favourite topics that he finds both amazing and amusing: (1) the problem of the possibility of subdividing a rectangle into a number of different squares; (2) the arrangement formed when several soap bubbles meet; and (3) circles and spheres.

Neuromuscular fatigue in racquet sports.

PubMed

Girard, Olivier; Millet, Grégoire P

2008-02-01

This article describes the physiologic and neural mechanisms that cause neuromuscular fatigue in racquet sports: table tennis, tennis, squash, and badminton. In these intermittent and dual activities, performance may be limited as a match progresses because of a reduced central activation, linked to changes in neurotransmitter concentration or in response to afferent sensory feedback. Alternatively, modulation of spinal loop properties may occur because of changes in metabolic or mechanical properties within the muscle. Finally, increased fatigue manifested by mistimed strokes, lower speed, and altered on-court movements may be caused by ionic disturbances and impairments in excitation-contraction coupling properties. These alterations in neuromuscular function contribute to decrease in racquet sports performance observed under fatigue.

Neuromuscular fatigue in racquet sports.

PubMed

Girard, Olivier; Millet, Grégoire P

2009-02-01

This article describes the physiologic and neural mechanisms that cause neuromuscular fatigue in racquet sports: table tennis, tennis, squash, and badminton. In these intermittent and dual activities, performance may be limited as a match progresses because of a reduced central activation, linked to changes in neurotransmitter concentration or in response to afferent sensory feedback. Alternatively, modulation of spinal loop properties may occur because of changes in metabolic or mechanical properties within the muscle. Finally, increased fatigue manifested by mistimed strokes, lower speed, and altered on-court movements may be caused by ionic disturbances and impairments in excitation-contraction coupling properties. These alterations in neuromuscular function contribute to decrease in racquet sports performance observed under fatigue.

Some Problems of Extremes in Geometry and Construction

ERIC Educational Resources Information Center

Yanovsky, Levi

2008-01-01

Two original problems in geometry are presented with solutions utilizing to differential calculus: (a) rectangle inscribed in a sector; (b) point on the ray of the angle. The possibility of applying mathematics in general and differential calculus in particular for solution of practical problems is discussed. (Contains 8 figures.)

Frequently Asked Questions - Naval Oceanography Portal

Science.gov Websites

high confidence. Circular TCFA areas are issued when a developing cyclone's speed and direction of ;, "Medium", and "High" mean on the ABIO and ABPW messages? What is a "Tropical rectangle? When does JTWC initiate warnings on tropical disturbances? How often are warnings updated by JTWC

The Day Search Stood Still

ERIC Educational Resources Information Center

Sexton, Will

2010-01-01

That little rectangle with a button next to it? (Those things called search boxes but might just as well be called "resource drains.") Imagine it disappearing from a library's webpages. The intricate works behind these design elements make up a major portion of what library staff spends time and money developing, populating, supporting,…

Secondary School Mathematics, Chapter 13, Perpendiculars and Parallels (I), Chapter 14, Similarity. Student's Text.

ERIC Educational Resources Information Center

Stanford Univ., CA. School Mathematics Study Group.

The first chapter of the seventh unit in this SMSG series discusses perpendiculars and parallels; topics covered include the relationship between parallelism and perpendicularity, rectangles, transversals, parallelograms, general triangles, and measurement of the circumference of the earth. The second chapter, on similarity, discusses scale…

Beyond the Golden Ratio: A Calculator-Based Investigation.

ERIC Educational Resources Information Center

Glidden, Peter L.

2001-01-01

Describes computation of a continued radical to approximate the golden ratio and presents two well-known geometric interpretations of it. Uses guided-discovery to investigate different repeated radicals to see what values they approximate, the golden-rectangle interpretation of these continued radicals, and the golden-section interpretation. (KHR)

Classroom Seating Considerations for 21st Century Students and Faculty

ERIC Educational Resources Information Center

Harvey, Eugene J.; Kenyon, Melaine C.

2013-01-01

This quantitative, cross-sectional research study explored students' perceptions of five different seating styles within typical classrooms in an urban public higher education institution. The five seating styles included: modern mobile chairs, tablet arm chairs, fixed tiered seating with tablet arms, rectangle tables with standard chairs, and…

3D fast adaptive correlation imaging for large-scale gravity data based on GPU computation

NASA Astrophysics Data System (ADS)

Chen, Z.; Meng, X.; Guo, L.; Liu, G.

2011-12-01

In recent years, large scale gravity data sets have been collected and employed to enhance gravity problem-solving abilities of tectonics studies in China. Aiming at the large scale data and the requirement of rapid interpretation, previous authors have carried out a lot of work, including the fast gradient module inversion and Euler deconvolution depth inversion ,3-D physical property inversion using stochastic subspaces and equivalent storage, fast inversion using wavelet transforms and a logarithmic barrier method. So it can be say that 3-D gravity inversion has been greatly improved in the last decade. Many authors added many different kinds of priori information and constraints to deal with nonuniqueness using models composed of a large number of contiguous cells of unknown property and obtained good results. However, due to long computation time, instability and other shortcomings, 3-D physical property inversion has not been widely applied to large-scale data yet. In order to achieve 3-D interpretation with high efficiency and precision for geological and ore bodies and obtain their subsurface distribution, there is an urgent need to find a fast and efficient inversion method for large scale gravity data. As an entirely new geophysical inversion method, 3D correlation has a rapid development thanks to the advantage of requiring no a priori information and demanding small amount of computer memory. This method was proposed to image the distribution of equivalent excess masses of anomalous geological bodies with high resolution both longitudinally and transversely. In order to tranform the equivalence excess masses into real density contrasts, we adopt the adaptive correlation imaging for gravity data. After each 3D correlation imaging, we change the equivalence into density contrasts according to the linear relationship, and then carry out forward gravity calculation for each rectangle cells. Next, we compare the forward gravity data with real data, and comtinue to perform 3D correlation imaging for the redisual gravity data. After several iterations, we can obtain a satisfactoy results. Newly developed general purpose computing technology from Nvidia GPU (Graphics Processing Unit) has been put into practice and received widespread attention in many areas. Based on the GPU programming mode and two parallel levels, five CPU loops for the main computation of 3D correlation imaging are converted into three loops in GPU kernel functions, thus achieving GPU/CPU collaborative computing. The two inner loops are defined as the dimensions of blocks and the three outer loops are defined as the dimensions of threads, thus realizing the double loop block calculation. Theoretical and real gravity data tests show that results are reliable and the computing time is greatly reduced. Acknowledgments We acknowledge the financial support of Sinoprobe project (201011039 and 201011049-03), the Fundamental Research Funds for the Central Universities (2010ZY26 and 2011PY0183), the National Natural Science Foundation of China (41074095) and the Open Project of State Key Laboratory of Geological Processes and Mineral Resources (GPMR0945).

''Math in a Can'': Teaching Mathematics and Engineering Design

ERIC Educational Resources Information Center

Narode, Ronald B.

2011-01-01

Using an apparently simple problem, ''Design a cylindrical can that will hold a liter of milk,'' this paper demonstrates how engineering design may facilitate the teaching of the following ideas to secondary students: linear and non-linear relationships; basic geometry of circles, rectangles, and cylinders; unit measures of area and volume;…

Early Development of Object Unity: Evidence for Perceptual Completion in Newborns

ERIC Educational Resources Information Center

Valenza, Eloisa; Bulf, Hermann

2011-01-01

The present study aimed to investigate whether perceptual completion is available at birth, in the absence of any visual experience. An extremely underspecified kinetic visual display composed of four spatially separated fragments arranged to give rise to an illusory rectangle that occluded a vertical rod (illusory condition) or rotated so as not…

Don't Fence Us in

ERIC Educational Resources Information Center

Carter, Chris

2010-01-01

Since teachers always teach area and perimeter together--and they are both introduced soon after the definition of a rectangle--it is not surprising that students mix up the notions of area and perimeter. Changing the investigation on maximising the area of a fixed perimeter from the traditional, but boring, "Sheep pens" to the much more…

Classroom Physical Design Influencing Student Learning and Evaluations of College Instructors: A Review of Literature

ERIC Educational Resources Information Center

Lei, Simon A.

2010-01-01

The physical design of classrooms, including studios, laboratories, auditoriums, and other indoor environments, can have a profound impact on student learning and subsequent overall ratings (student evaluations) of college instructors. Many college classrooms have been conventionally designed in the shape of a square or a rectangle, with…

The Case for the L-Shaped Classroom.

ERIC Educational Resources Information Center

Dyck, James A.

1994-01-01

Classroom shape is an important variable in educational quality. The traditional squat rectangle may be counterproductive to the learning process. The fat L-shaped classroom, compared to H, X, and T shapes, offers good separation, is more compact, and provides good visibility and ease of movement for the teacher. It has excellent nesting…

Scaffolding for Access to Productive Struggle

ERIC Educational Resources Information Center

Barlow, Angela T.; Gerstenschlager, Natasha E.; Strayer, Jeremy F.; Lischka, Alyson E.; Stephens, D. Christopher; Hartland, Kristin S.; Willingham, J. Christopher

2018-01-01

This article begins by describing a class scenario in which a teacher gives her students the L problem (Watanabe 2008), which involves finding the area of a composite figure. Her students inappropriately extend the area formula for rectangles (A = L x W) to composite figures by multiplying all given dimensions. After class, the teacher concluded…

Developmental and Individual Differences in Children's Area Judgment Rules.

ERIC Educational Resources Information Center

Silverman, Irwin W.; Paskewitz, Sabra Lee

1988-01-01

Investigated whether children in kindergarten and grades 2 and 4 applied one- or two-dimensional rules in rating areas of rectangles, triangles, and ellipses. A majority of subjects produced judgments consistent with one of the rules. The findings contradict Piaget's claim that young children are limited to one-dimensional judgments. (SKC)

76 FR 19290 - Safety Zone; Commencement Bay, Tacoma, WA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-07

... the following points Latitude 47[deg]17'38'' N, Longitude 122[deg]28'43'' W; thence south easterly to... protruding from the shoreline along Ruston Way. Floating markers will be placed by the sponsor of the event... rectangle protruding from the shoreline along Ruston Way. Floating markers will be placed by the sponsor of...

Modelling Problem-Solving Situations into Number Theory Tasks: The Route towards Generalisation

ERIC Educational Resources Information Center

Papadopoulos, Ioannis; Iatridou, Maria

2010-01-01

This paper examines the way two 10th graders cope with a non-standard generalisation problem that involves elementary concepts of number theory (more specifically linear Diophantine equations) in the geometrical context of a rectangle's area. Emphasis is given on how the students' past experience of problem solving (expressed through interplay…

2. GARAGE. VIEW LOOKING NORTHWEST. THE ORIGINAL DOOR IN THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. GARAGE. VIEW LOOKING NORTHWEST. THE ORIGINAL DOOR IN THE SOUTHEND HAS BEEN INFILLED. THE DARK RECTANGLE (AT RIGHT OF WINDOW) IS A PIECE OF PLYWOOD WITH AN ELECTRICAL RECEPTACLE ITS PURPOSE WAS NOT DETERMINED. - Tonto Ranger Station, Garage, Forest Service Road 65 at Tonto Wash, Skull Valley, Yavapai County, AZ

Contour entropy: a new determinant of perceiving ground or a hole.

PubMed

Gillam, Barbara J; Grove, Philip M

2011-06-01

Figure-ground perception is typically described as seeing one surface occluding another. Figure properties, not ground properties, are considered the significant factors. In scenes, however, a near surface will often occlude multiple contours and surfaces, often at different depths, producing alignments that are improbable except under conditions of occlusion. We thus hypothesized that unrelated (high entropy) lines would tend to appear as ground in a figure-ground paradigm more often than similarly aligned ordered (low entropy) lines. We further hypothesized that for lines spanning a closed area, high line entropy should increase the hole-like appearance of that area. These predictions were confirmed in three experiments. The probability that patterned rectangles were seen as ground when alternated with blank rectangles increased with pattern entropy. A single rectangular shape appeared more hole-like when the entropy of the enclosed contours increased. Furthermore, these same contours, with the outline shape removed, gave rise to bounding illusory contours whose strength increased with contour entropy. We conclude that figure-ground and hole perception can be determined by properties of ground in the absence of any figural shape, or surround, factors.

MDTri: robust and efficient global mixed integer search of spaces of multiple ternary alloys: A DIRECT-inspired optimization algorithm for experimentally accessible computational material design

DOE PAGES

Graf, Peter A.; Billups, Stephen

2017-07-24

Computational materials design has suffered from a lack of algorithms formulated in terms of experimentally accessible variables. Here we formulate the problem of (ternary) alloy optimization at the level of choice of atoms and their composition that is normal for synthesists. Mathematically, this is a mixed integer problem where a candidate solution consists of a choice of three elements, and how much of each of them to use. This space has the natural structure of a set of equilateral triangles. We solve this problem by introducing a novel version of the DIRECT algorithm that (1) operates on equilateral triangles insteadmore » of rectangles and (2) works across multiple triangles. We demonstrate on a test case that the algorithm is both robust and efficient. Lastly, we offer an explanation of the efficacy of DIRECT -- specifically, its balance of global and local search -- by showing that 'potentially optimal rectangles' of the original algorithm are akin to the Pareto front of the 'multi-component optimization' of global and local search.« less

Characterization Of Improved Binary Phase-Only Filters In A Real-Time Coherent Optical Correlation System

NASA Astrophysics Data System (ADS)

Flannery, D.; Keller, P.; Cartwright, S.; Loomis, J.

1987-06-01

Attractive correlation system performance potential is possible using magneto-optic spatial light modulators (SLM) to implement binary phase-only reference filters at high rates, provided the correlation performance of such reduced-information-content filters is adequate for the application. In the case studied here, the desired filter impulse response is a rectangular shape, which cannot be achieved with the usual binary phase-only filter formulation. The correlation application problem is described and techniques for synthesizing improved filter impulse response are considered. A compromise solution involves the cascading of a fixed amplitude-only weighting mask with the binary phase-only SLM. Based on simulations presented, this approach provides improved impulse responses and good correlation performance, while retaining the critical feature of real-time variations of the size, shape, and orientation of the rectangle by electronic programming of the phase pattern in the SLM. Simulations indicate that, for at least one very challenging input scene clutter situation, these filters provide higher correlation signal-to-noise than does "ideal" correlation, i.e. using a perfect rectangle filter response.

MDTri: robust and efficient global mixed integer search of spaces of multiple ternary alloys: A DIRECT-inspired optimization algorithm for experimentally accessible computational material design

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

Graf, Peter A.; Billups, Stephen

Computational materials design has suffered from a lack of algorithms formulated in terms of experimentally accessible variables. Here we formulate the problem of (ternary) alloy optimization at the level of choice of atoms and their composition that is normal for synthesists. Mathematically, this is a mixed integer problem where a candidate solution consists of a choice of three elements, and how much of each of them to use. This space has the natural structure of a set of equilateral triangles. We solve this problem by introducing a novel version of the DIRECT algorithm that (1) operates on equilateral triangles insteadmore » of rectangles and (2) works across multiple triangles. We demonstrate on a test case that the algorithm is both robust and efficient. Lastly, we offer an explanation of the efficacy of DIRECT -- specifically, its balance of global and local search -- by showing that 'potentially optimal rectangles' of the original algorithm are akin to the Pareto front of the 'multi-component optimization' of global and local search.« less

Automated fall detection on privacy-enhanced video.

PubMed

Edgcomb, Alex; Vahid, Frank

2012-01-01

A privacy-enhanced video obscures the appearance of a person in the video. We consider four privacy enhancements: blurring of the person, silhouetting of the person, covering the person with a graphical box, and covering the person with a graphical oval. We demonstrate that an automated video-based fall detection algorithm can be as accurate on privacy-enhanced video as on raw video. The algorithm operated on video from a stationary in-home camera, using a foreground-background segmentation algorithm to extract a minimum bounding rectangle (MBR) around the motion in the video, and using time series shapelet analysis on the height and width of the rectangle to detect falls. We report accuracy applying fall detection on 23 scenarios depicted as raw video and privacy-enhanced videos involving a sole actor portraying normal activities and various falls. We found that fall detection on privacy-enhanced video, except for the common approach of blurring of the person, was competitive with raw video, and in particular that the graphical oval privacy enhancement yielded the same accuracy as raw video, namely 0.91 sensitivity and 0.92 specificity.

Attention, spatial integration, and the tail of response time distributions in Stroop task performance.

PubMed

Roelofs, Ardi

2012-01-01

A few studies have examined selective attention in Stroop task performance through ex-Gaussian analyses of response time (RT) distributions. It has remained unclear whether the tail of the RT distribution in vocal responding reflects spatial integration of relevant and irrelevant attributes, as suggested by Spieler, Balota, and Faust (2000). Here, two colour-word Stroop experiments with vocal responding are reported in which the spatial relation between colour and word was manipulated. Participants named colours (e.g., green; say "green") while trying to ignore distractors that were incongruent or congruent words (e.g., red or green), or neutral series of Xs. The vocal RT was measured. Colour words in colour, white words superimposed onto colour rectangles (Experiment 1), and colour rectangles combined with auditory words (Experiment 2) yielded Stroop effects in both the leading edge and the tail of the RT distributions. These results indicate that spatial integration is not necessary for effects in the tail to occur in vocal responding. It is argued that the findings are compatible with an association of the tail effects with task conflict.

Study of moving object detecting and tracking algorithm for video surveillance system

NASA Astrophysics Data System (ADS)

Wang, Tao; Zhang, Rongfu

2010-10-01

This paper describes a specific process of moving target detecting and tracking in the video surveillance.Obtain high-quality background is the key to achieving differential target detecting in the video surveillance.The paper is based on a block segmentation method to build clear background,and using the method of background difference to detecing moving target,after a series of treatment we can be extracted the more comprehensive object from original image,then using the smallest bounding rectangle to locate the object.In the video surveillance system, the delay of camera and other reasons lead to tracking lag,the model of Kalman filter based on template matching was proposed,using deduced and estimated capacity of Kalman,the center of smallest bounding rectangle for predictive value,predicted the position in the next moment may appare,followed by template matching in the region as the center of this position,by calculate the cross-correlation similarity of current image and reference image,can determine the best matching center.As narrowed the scope of searching,thereby reduced the searching time,so there be achieve fast-tracking.

Sensory motor systems of artificial and natural hands.

PubMed

Chappell, Paul H; Cranny, Andy; Cotton, Darryl P J; White, Neil M; Beeby, Steve P

2007-12-01

The surgeon Ambroise Paré designed an anthropomorphic hand for wounded soldiers in the 16th century. Since that time, there have been advances in technology through the use of computer-aided design, modern materials, electronic controllers and sensors to realise artificial hands which have good functionality and reliability. Data from touch, object slip, finger position and temperature sensors, mounted in the fingers and on the palm, can be used in feedback loops to automatically hold objects. A study of the natural neuromuscular systems reveals a complexity which can only in part be realised today with technology. Highlights of the parallels and differences between natural and artificial hands are discussed with reference to the Southampton Hand. The anatomical structure of parts of the natural systems can be made artificially such as the antagonist muscles using tendons. Theses solutions look promising as they are based on the natural form but in practice lack the desired physical specification. However, concepts of the lower spinal loops can be mimicked in principle. Some future devices will require greater skills from the surgeon to create the interface between the natural system and an artificial device. Such developments may offer a more natural control with ease of use for the limb deficient person.

Numerical results for near surface time domain electromagnetic exploration: a full waveform approach

NASA Astrophysics Data System (ADS)

Sun, H.; Li, K.; Li, X., Sr.; Liu, Y., Sr.; Wen, J., Sr.

2015-12-01

Time domain or Transient electromagnetic (TEM) survey including types with airborne, semi-airborne and ground play important roles in applicants such as geological surveys, ground water/aquifer assess [Meju et al., 2000; Cox et al., 2010], metal ore exploration [Yang and Oldenburg, 2012], prediction of water bearing structures in tunnels [Xue et al., 2007; Sun et al., 2012], UXO exploration [Pasion et al., 2007; Gasperikova et al., 2009] etc. The common practice is introducing a current into a transmitting (Tx) loop and acquire the induced electromagnetic field after the current is cut off [Zhdanov and Keller, 1994]. The current waveforms are different depending on instruments. Rectangle is the most widely used excitation current source especially in ground TEM. Triangle and half sine are commonly used in airborne and semi-airborne TEM investigation. In most instruments, only the off time responses are acquired and used in later analysis and data inversion. Very few airborne instruments acquire the on time and off time responses together. Although these systems acquire the on time data, they usually do not use them in the interpretation.This abstract shows a novel full waveform time domain electromagnetic method and our recent modeling results. The benefits comes from our new algorithm in modeling full waveform time domain electromagnetic problems. We introduced the current density into the Maxwell's equation as the transmitting source. This approach allows arbitrary waveforms, such as triangle, half-sine, trapezoidal waves or scatter record from equipment, being used in modeling. Here, we simulate the establishing and induced diffusion process of the electromagnetic field in the earth. The traditional time domain electromagnetic with pure secondary fields can also be extracted from our modeling results. The real time responses excited by a loop source can be calculated using the algorithm. We analyze the full time gates responses of homogeneous half space and two layered models with half sine current waveform as examples. We find the on time responses are quite sensitive to resistivity or depth changes. The results show the potential use of full waveform responses in time domain electromagnetic surveys.

Generation and characterization of Atoh1-Cre knock-in mouse line

PubMed Central

Yang, Hua; Xie, Xiaoling; Deng, Min; Chen, Xiaowei; Gan, Lin

2010-01-01

Summary Atoh1 encodes a basic helix-loop-helix (bHLH) transcription factor required for the development of the inner ear sensory epithelia, the dorsal spinal cord, brainstem, cerebellum, and intestinal secretory cells. In this study to create a genetic tool for the research on gene function in the ear sensory organs, we generated an Atoh1-Cre knock-in mouse line by replacing the entire Atoh1 coding sequences with the Cre coding sequences. Atoh1Cre/+mice were viable, fertile, and displayed no visible defects whereas the Atoh1Cre/Cremice died perinatally. The spatiotemporal activities of Cre recombinase were examined by crossing Atoh1-Cre mice with the R26R-lacZ conditional reporter mice. Atoh1-Cre activities were detected in the developing inner ear, the hindbrain, the spinal cord, and the intestine. In the inner ear, Atoh1-Cre activities were confined to the sensory organs in which lacZ expression is detected in nearly all of the hair cells and in many supporting cells. Thus, Atoh1-Cre mouse line serves as a useful tool for the functional study of genes in the inner ear. In addition, our results demonstrate that Atoh1 is expressed in the common progenitors destined for both hair and supporting cells. PMID:20533400

Real-time evaluation of a noninvasive neuroprosthetic interface for control of reach.

PubMed

Corbett, Elaine A; Körding, Konrad P; Perreault, Eric J

2013-07-01

Injuries of the cervical spinal cord can interrupt the neural pathways controlling the muscles of the arm, resulting in complete or partial paralysis. For individuals unable to reach due to high-level injuries, neuroprostheses can restore some of the lost function. Natural, multidimensional control of neuroprosthetic devices for reaching remains a challenge. Electromyograms (EMGs) from muscles that remain under voluntary control can be used to communicate intended reach trajectories, but when the number of available muscles is limited control can be difficult and unintuitive. We combined shoulder EMGs with target estimates obtained from gaze. Natural gaze data were integrated with EMG during closed-loop robotic control of the arm, using a probabilistic mixture model. We tested the approach with two different sets of EMGs, as might be available to subjects with C4- and C5-level spinal cord injuries. Incorporating gaze greatly improved control of reaching, particularly when there were few EMG signals. We found that subjects naturally adapted their eye-movement precision as we varied the set of available EMGs, attaining accurate performance in both tested conditions. The system performs a near-optimal combination of both physiological signals, making control more intuitive and allowing a natural trajectory that reduces the burden on the user.

Simulating resonance-mediated two-photon absorption enhancement in rare-earth ions by a rectangle phase modulation

NASA Astrophysics Data System (ADS)

Qi, Da-Long; Zheng, Ye; Cheng, Wen-Jing; Yao, Yun-Hua; Deng, Lian-Zhong; Feng, Dong-Hai; Jia, Tian-Qing; Sun, Zhen-Rong; Zhang, Shi-An

2018-01-01

Not Available Project supported by the National Natural Science Foundation of China (Grant No. 11474096), the Science and Technology Commission of Shanghai Municipality, China (Grant Nos. 14JC1401500, 17ZR146900, and 16520721200), and the Higher Education Key Program of He’nan Province of China (Grant No. 17A140025).

Freddie Fish. A Primary Environmental Study of Basic Numerals, Sets, Ordinals and Shapes.

ERIC Educational Resources Information Center

Kraynak, Ola

This teacher's guide and study guide are an environmental approach to mathematics education in the primary grades. The mathematical studies of the numerals 0-10, ordinals, number sets, and basic shapes - diamond, circle, square, rectangle, and triangle - are developed through the story of Freddie Fish and his search for clean water. The…

Eye Gaze versus Arrows as Spatial Cues: Two Qualitatively Different Modes of Attentional Selection

ERIC Educational Resources Information Center

Marotta, Andrea; Lupianez, Juan; Martella, Diana; Casagrande, Maria

2012-01-01

This study aimed to evaluate the type of attentional selection (location- and/or object-based) triggered by two different types of central noninformative cues: eye gaze and arrows. Two rectangular objects were presented in the visual field, and subjects' attention was directed to the end of a rectangle via the observation of noninformative…

Mathematical Representation by Students in Building Relational Understanding on Concepts of Area and Perimeter of Rectangle

ERIC Educational Resources Information Center

Anwar, Rahmad Bustanul; Yuwono, Ipung; As'ari, Abdur Rahman; Sisworo; Dwi, Rahmawati

2016-01-01

Representation is an important aspect of learners in building a relational understanding of mathematical concepts. But the ability of a mathematical representation of students in building relational understanding is still very limited. The purpose of this research is to description of mathematical representation of students who appear in building…

A Monte Carlo Application to Approximate the Integral from a to b of e Raised to the x Squared.

ERIC Educational Resources Information Center

Easterday, Kenneth; Smith, Tommy

1992-01-01

Proposes an alternative means of approximating the value of complex integrals, the Monte Carlo procedure. Incorporating a discrete approach and probability, an approximation is obtained from the ratio of computer-generated points falling under the curve to the number of points generated in a predetermined rectangle. (MDH)

A Quilt of Many Colors

ERIC Educational Resources Information Center

Masse, Don

2012-01-01

The author discovered artist Eleanor McCain's work on "Dear Ada," an art blog he follows. McCain makes brightly colored art quilts using various rectangles and squares. She creates visual "pop" by using these shapes in a variety of sizes and bright colors. There is an interesting spatial "push and pull" that happens when looking at her quilts.…

Automated Scoring of an Interactive Geometry Item: A Proof-of-Concept

ERIC Educational Resources Information Center

Masters, Jessica

2010-01-01

An online interactive geometry item was developed to explore students' abilities to create prototypical and "tilted" rectangles out of line segments. The item was administered to 1,002 students. The responses to the item were hand-coded as correct, incorrect, or incorrect with possible evidence of a misconception. A variation of the nearest…

Fiber sample presentation system for spectrophotometer cotton fiber color measurements

USDA-ARS?s Scientific Manuscript database

The Uster® High Volume Instrument (HVI) is used to class U.S. cotton for fiber color, yielding the industry accepted, cotton-specific color parameters Rd and +b. The HVI examines a 9 square inch fiber sample, and it is also used to test large AMS standard cotton “biscuits” or rectangles. Much inte...

Area Judgment from Width and Height Information: The Case of the Rectangle.

ERIC Educational Resources Information Center

Mullet, Etienne; Rulence-Paques, Patricia

1998-01-01

Adults, 9-year olds, and 5-year olds were shown horizontal and vertical lines of various sizes, presented on same wall or different walls, and asked to estimate corresponding area. Responses indicated that when width and height were separated, children gave same weight to both dimensions while adults gave greater weight to larger dimensions; when…

Stage Costumes for Girls.

ERIC Educational Resources Information Center

Greenhowe, Jean

This book contains full instructions for making 14 costumes for girls to fit any sizes up to about 147 cm (4 feet 10 inches) in height. All the garments can be made to fit any child's individual measurements without the need of complicated pattern pieces. Simple basic shapes such as rectangles and circles are used for the patterns and the only…

Redacting with Confidence: How to Safely Publish Sanitized Reports Converted from Word to PDF

DTIC Science & Technology

2006-02-02

select Insert->Picture-> Autoshapes from the top menu bar (this opens the AutoShapes toolbar). Select the rectangle from the Autoshapes toolbar as in... AutoShape from the menu as in Figure 6 (this opens the Format AutoShape dialog box), select the Size tab, enter the desired height and width of the

A Deduction of the Golden Spiral Equation via Powers of the Golden Ratio ?

ERIC Educational Resources Information Center

Zahn, Maurício

2017-01-01

This paper presents an interesting deduction of the Golden Spiral equation in a suitable polar coordinate system. For this purpose, the concepts of Golden Ratio and Golden Rectangle, and a significant result for the calculation of powers of the Golden Ratio ? using terms of the Fibonacci sequence are mentioned. Finally, various geometrical…

A Historical Note on the Proof of the Area of a Circle

ERIC Educational Resources Information Center

Wilamowsky, Yonah; Epstein, Sheldon; Dickman, Bernard

2011-01-01

Proofs that the area of a circle is nr[superscript 2] can be found in mathematical literature dating as far back as the time of the Greeks. The early proofs, e.g. Archimedes, involved dividing the circle into wedges and then fitting the wedges together in a way to approximate a rectangle. Later more sophisticated proofs relied on arguments…

Monolithic Laser.

DTIC Science & Technology

1977-09-01

procedures that could be effectively used . Neither chemical nor in situ vapor etch techniques alleviated these problems. The presence of M in the top...mask consisting of rectangles 300 um x 200 urn. The crystal is then chemically etched in two steps. First, a calibrated Na0H:H.0. 39 etch ^ is used ... fabricated (including optical cavity formation) monolithically using conventional photolithographic fabrication technology. This development is a

Wheels Don't Have to Be Round

ERIC Educational Resources Information Center

Laird, Shirley

2012-01-01

Every year, the author's eighth-graders do some projects on color mixing and color schemes. In this article, the author gives a twist to the basic color wheel. Using rough-draft paper the same size as the paper they would eventually work on, students were to figure out a way to divide it into six spaces. They were not limited to basic rectangles,…

Nondestructive Quantitative Sampling for Freshwater Mussels in Variable Substrate Streams

Treesearch

John B. Richardson; Winston Paul Smith

1994-01-01

Unionidmussels were sampled in the Big South Fork of the Cumberland River, Tennessee and Kentucky, from July to October 1988 with a chain grid of10 l-m2 quadrats. The chain grid was used to define 100-m2 areas along the stream bed by repeatedly moving the10-m2 rectangle upstream. Within each100-m

Children's Conceptions of Area Measurement and Their Strategies for Solving Area Measurement Problems

ERIC Educational Resources Information Center

Huang, Hsin-Mei E.; Witz, Klaus G.

2013-01-01

This study investigated children's understanding of area measurement, including the concept of area and the area formula of a rectangle, as well as their strategic knowledge for solving area measurement problems. Twenty-two fourth-graders from three classes of a public elementary school in Taipei, Taiwan, participated in a one-on-one interview.…

Modern Geometric Algebra: A (Very Incomplete!) Survey

ERIC Educational Resources Information Center

Suzuki, Jeff

2009-01-01

Geometric algebra is based on two simple ideas. First, the area of a rectangle is equal to the product of the lengths of its sides. Second, if a figure is broken apart into several pieces, the sum of the areas of the pieces equals the area of the original figure. Remarkably, these two ideas provide an elegant way to introduce, connect, and…

46 CFR 160.072-3 - General performance requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

....072-3 General performance requirements. (a) Each flag must: (1) Be a square or rectangle at least 90... colored a bright red-orange color; (3) Display a black disc and a black square on the red-orange... square shall be equal, and shall each be 1/3 of the length of the longest side of the flag, or 30 cm (12...

46 CFR 160.072-3 - General performance requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

....072-3 General performance requirements. (a) Each flag must: (1) Be a square or rectangle at least 90... colored a bright red-orange color; (3) Display a black disc and a black square on the red-orange... square shall be equal, and shall each be 1/3 of the length of the longest side of the flag, or 30 cm (12...

46 CFR 160.072-3 - General performance requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

....072-3 General performance requirements. (a) Each flag must: (1) Be a square or rectangle at least 90... colored a bright red-orange color; (3) Display a black disc and a black square on the red-orange... square shall be equal, and shall each be 1/3 of the length of the longest side of the flag, or 30 cm (12...

46 CFR 160.072-3 - General performance requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

....072-3 General performance requirements. (a) Each flag must: (1) Be a square or rectangle at least 90... colored a bright red-orange color; (3) Display a black disc and a black square on the red-orange... square shall be equal, and shall each be 1/3 of the length of the longest side of the flag, or 30 cm (12...

46 CFR 160.072-3 - General performance requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

....072-3 General performance requirements. (a) Each flag must: (1) Be a square or rectangle at least 90... colored a bright red-orange color; (3) Display a black disc and a black square on the red-orange... square shall be equal, and shall each be 1/3 of the length of the longest side of the flag, or 30 cm (12...

Enhancement of the Computer Lumber Grading Program to Support Polygonal Defects

Treesearch

Powsiri Klinkhachorn; R. Kathari; D. Yost; Philip A. Araman

1993-01-01

Computer grading of hardwood lumber promises to avoid regrading of the same lumber because of disagreements between the buyer and the seller. However, the first generation of computer programs for hardwood lumber grading simplify the process by modeling defects on the board as rectangles. This speeds up the grading process buy can inadvertently put a board into a lower...

Quantitatively analyzing the mechanism of giant circular dichroism in extrinsic plasmonic chiral nanostructures by tracking the interplay of electric and magnetic dipoles.

PubMed

Hu, Li; Tian, Xiaorui; Huang, Yingzhou; Fang, Liang; Fang, Yurui

2016-02-14

Plasmonic chirality has drawn much attention because of tunable circular dichroism (CD) and the enhancement for chiral molecule signals. Although various mechanisms have been proposed to explain the plasmonic CD, a quantitative explanation like the ab initio mechanism for chiral molecules, is still unavailable. In this study, a mechanism similar to the mechanisms associated with chiral molecules was analyzed. The giant extrinsic circular dichroism of a plasmonic splitting rectangle ring was quantitatively investigated from a theoretical standpoint. The interplay of the electric and magnetic modes of the meta-structure is proposed to explain the giant CD. We analyzed the interplay using both an analytical coupled electric-magnetic dipole model and a finite element method model. The surface charge distributions showed that the circular current yielded by the splitting rectangle ring causes the ring to behave like a magneton at some resonant modes, which then interact with the electric modes, resulting in a mixing of the two types of modes. The strong interplay of the two mode types is primarily responsible for the giant CD. The analysis of the chiral near-field of the structure shows potential applications for chiral molecule sensing.

Working memory capacity of biological movements predicts empathy traits.

PubMed

Gao, Zaifeng; Ye, Tian; Shen, Mowei; Perry, Anat

2016-04-01

Working memory (WM) and empathy are core issues in cognitive and social science, respectively. However, no study so far has explored the relationship between these two constructs. Considering that empathy takes place based on the others' observed experiences, which requires extracting the observed dynamic scene into WM and forming a coherent representation, we hypothesized that a sub-type of WM capacity, i.e., WM for biological movements (BM), should predict one's empathy level. Therefore, WM capacity was measured for three distinct types of stimuli in a change detection task: BM of human beings (BM; Experiment 1), movements of rectangles (Experiment 2), and static colors (Experiment 3). The first two stimuli were dynamic and shared one WM buffer which differed from the WM buffer for colors; yet only the BM conveyed social information. We found that BM-WM capacity was positively correlated with both cognitive and emotional empathy, with no such correlations for WM capacity of movements of rectangles or of colors. Thus, the current study is the first to provide evidence linking a specific buffer of WM and empathy, and highlights the necessity for considering different WM capacities in future social and clinical research.

Mesoscopic Simulations of Adsorption and Association of PEO-PPO-PEO Triblock Copolymers on a Hydrophobic Surface: From Mushroom Hemisphere to Rectangle Brush.

PubMed

Song, Xianyu; Zhao, Shuangliang; Fang, Shenwen; Ma, Yongzhang; Duan, Ming

2016-11-08

The dissipative particle dynamics (DPD) method is used to investigate the adsorption behavior of PEO-PPO-PEO triblock copolymers at the liquid/solid interface. The effect of molecular architecture on the self-assembled monolayer adsorption of PEO-PPO-PEO triblock copolymers on hydrophobic surfaces is elucidated by the adsorption process, film properties, and adsorption morphologies. The adsorption thicknesses on hydrophobic surfaces and the diffusion coefficient as well as the aggregation number of Pluronic copolymers in aqueous solution observed in our simulations agree well with previous experimental and numerical observations. The radial distribution function revealed that the ability of self-assembly on hydrophobic surfaces is P123 > P84 > L64 > P105 > F127, which increased with the EO ratio of the Pluronic copolymers. Moreover, the shape parameter and the degree of anisotropy increase with increasing molecular weight and mole ratio of PO of the Pluronic copolymers. Depending on the conformation of different Pluronic copolymers, the morphology transition of three regimes on hydrophobic surfaces is present: mushroom or hemisphere, progressively semiellipsoid, and rectangle brush regimes induced by decreasing molecular weight and mole ratio of EO of Pluronic copolymers.

Automated Planar Tracking the Waving Bodies of Multiple Zebrafish Swimming in Shallow Water.

PubMed

Wang, Shuo Hong; Cheng, Xi En; Qian, Zhi-Ming; Liu, Ye; Chen, Yan Qiu

2016-01-01

Zebrafish (Danio rerio) is one of the most widely used model organisms in collective behavior research. Multi-object tracking with high speed camera is currently the most feasible way to accurately measure their motion states for quantitative study of their collective behavior. However, due to difficulties such as their similar appearance, complex body deformation and frequent occlusions, it is a big challenge for an automated system to be able to reliably track the body geometry of each individual fish. To accomplish this task, we propose a novel fish body model that uses a chain of rectangles to represent fish body. Then in detection stage, the point of maximum curvature along fish boundary is detected and set as fish nose point. Afterwards, in tracking stage, we firstly apply Kalman filter to track fish head, then use rectangle chain fitting to fit fish body, which at the same time further judge the head tracking results and remove the incorrect ones. At last, a tracklets relinking stage further solves trajectory fragmentation due to occlusion. Experiment results show that the proposed tracking system can track a group of zebrafish with their body geometry accurately even when occlusion occurs from time to time.

Quantum transport in chaotic and integrable ballistic cavities with tunable shape

NASA Astrophysics Data System (ADS)

Lee, Y.; Faini, G.; Mailly, D.

1997-10-01

We have performed magnetotransport measurements in ballistic cavities and obtained the average by small modulations on the shapes and/or on the Fermi level. We work with cavities whose underlying classical dynamics is chaotic (stadia and Sinaï billiards) and integrable (circles and rectangles). The former show a Lorentzian weak-localization peak, in agreement with semiclassical predictions and other averaging methods that have been used in recent measurements. For integrable cavities our measurements show that the shape of the weak localization is very sensitive to the exact geometry of the sample: a linear magnetoconductance has been observed for rectangles as expected by the theory for integrable cavities, whereas for circles the shape is always Lorentzian. These discrepancies illustrate the nongeneric behavior of scattering through integrable geometries, that we analyze taking into account the interplay of integrability with smooth disorder and geometrical effects. The power spectra of the conductance fluctuations are also analyzed, the deduced typical areas are in good agreement with those obtained from the weak localization. Periodic orbits in nonaveraged Fourier transforms of the magnetoconductance for regular cavities are clearly identified indicating the good quality of our samples.

Pupillary correlates of covert shifts of attention during working memory maintenance.

PubMed

Unsworth, Nash; Robison, Matthew K

2017-04-01

The pupillary light reflex (PLR) was used to track covert shifts of attention to items maintained in visual working memory (VWM). In three experiments, participants performed a change detection task in which rectangles appeared on either side of fixation and at test participants indicated if the cued rectangle changed its orientation. Prior to presentation or during the delay, participants were cued to the light or dark side of the screen. When cued to the light side, the pupil constricted, and when cued to the dark side, the pupil dilated, suggesting that the PLR tracked covert shifts of attention. Similar covert shifts of attention were seen when the target stimuli remained onscreen and during a blank delay period, suggesting similar effects for attention to perceptual stimuli and attention to stimuli maintained in VWM. Furthermore, similar effects were demonstrated when participants were pre-cued or retro-cued to the prioritized location, suggesting that shifts of covert attention can occur both before and after target presentation. These results are consistent with prior research, suggesting an important role of covert shifts of attention during VWM maintenance and that the PLR can be used to track these covert shifts of attention.

Rectangle-capped and tilted micropillar array for enhanced anisotropic anti-shearing in biomimetic adhesion

PubMed Central

Wang, Yue; Li, Xiangming; Tian, Hongmiao; Hu, Hong; Tian, Yu; Shao, Jinyou; Ding, Yucheng

2015-01-01

Dry adhesion observed in the feet of various small creatures has attracted considerable attention owing to the unique advantages such as self-cleaning, adaptability to rough surfaces along with repeatable and reversible adhesiveness. Among these advantages, for practical applications, proper detachability is critical for dry adhesives with artificial microstructures. In this study, we present a microstructured array consisting of both asymmetric rectangle-capped tip and tilted shafts, which produce an orthogonal anisotropy of the shearing strength along the long and short dimensions of the tip, with a maximum anti-shearing in the two directions along the longer dimension. Meanwhile, the tilt feature can enhance anisotropic shearing adhesion by increasing shearing strength in the forward shearing direction and decreasing strength in the reverse shearing direction along the short dimension of the tip, leading to a minimum anti-shearing in only one of the two directions along the shorter dimension of the rectangular tip. Such a microstructured adhesive with only one weak shearing direction, leading to well-controlled attachment and detachment of the adhesive, is created in our experiment by conventional double-sided exposure of a photoresist followed by a moulding process. PMID:25808338

Automated Planar Tracking the Waving Bodies of Multiple Zebrafish Swimming in Shallow Water

PubMed Central

Wang, Shuo Hong; Cheng, Xi En; Qian, Zhi-Ming; Liu, Ye; Chen, Yan Qiu

2016-01-01

Zebrafish (Danio rerio) is one of the most widely used model organisms in collective behavior research. Multi-object tracking with high speed camera is currently the most feasible way to accurately measure their motion states for quantitative study of their collective behavior. However, due to difficulties such as their similar appearance, complex body deformation and frequent occlusions, it is a big challenge for an automated system to be able to reliably track the body geometry of each individual fish. To accomplish this task, we propose a novel fish body model that uses a chain of rectangles to represent fish body. Then in detection stage, the point of maximum curvature along fish boundary is detected and set as fish nose point. Afterwards, in tracking stage, we firstly apply Kalman filter to track fish head, then use rectangle chain fitting to fit fish body, which at the same time further judge the head tracking results and remove the incorrect ones. At last, a tracklets relinking stage further solves trajectory fragmentation due to occlusion. Experiment results show that the proposed tracking system can track a group of zebrafish with their body geometry accurately even when occlusion occurs from time to time. PMID:27128096

`Hardcastle Hollows' in loess landforms: Closed depressions in aeolian landscapes - in a geoheritage context

NASA Astrophysics Data System (ADS)

Fagg, Roger; Smalley, Ian

2018-04-01

Loess landscapes sometimes contain isolated depressed areas, which often appear as lakes. The outline shape (and distribution) of these depressions could be controlled by random processes, particularly if the depressions are caused by loess hydroconsolidation and ground subsidence. By applying the Zingg system of shape classification it is possible to propose a mean random shape for the closed depressions. A Zingg rectangle with a side ratio of about 2:1 is produced by a very simple Monte Carlo method, which had been used previously to calculate the mean random shape of a loess particle. The Zingg rectangle indicates the basic shape of the mean closed depression. A simple four stage process for the formation of the depressions is proposed. They might be called `Hardcastle Hollows' in honour of John Hardcastle who first reported them, in New Zealand. Studies on Ukrainian deposits suggest that there might be some stratigraphic value in the observation of closed depressions; they are often not superimposed in successive depositions of loess. Hydroconsolidation is important in landscape processes. The hollows provide interesting habitats and enlarge the ecological interest of loess deposits; the geoheritage scene is enhanced.

Grinding Wheel Profile

NASA Technical Reports Server (NTRS)

2004-01-01

This graphic dubbed by engineers as the 'Grinding Wheel Profile' is the detective's tool used by the Opportunity team to help them understand one of the processes that formed the interior of a rock called 'McKittrick.' Scientists are looking for clues as to how layers, grains and minerals helped create this rock, and the engineers who built the rock abrasion tool (RAT) wanted to ensure that their instrument's handiwork did not get confused with natural processes.

In the original microscopic image underlaying the graphics, engineers and scientists noticed 'layers' or 'scratches' on the spherical object nicknamed 'blueberry' in the lower right part of the image. The designers of the rock abrasion tool noticed that the arc length and width of the scratches were similar to the shape and size of the rock abrasion tool's grinding wheel, which is made out of a pad of diamond teeth.

The scrapes on the bottom right blueberry appear to be caused by the fact that the berry got dislodged slightly and its surface was scraped with the grinding pad. In this image, the largest yellow circle is the overall diameter of the hole ground by the rock abrasion tool and the largest yellow rectangular shape is the area of the grinding wheel bit. The smaller yellow semi-circle is the path that the center of the grinding tool follows. The orange arrow arcing around the solid yellow circle (center of grinding tool) indicates the direction that the grinding tool spins around its own center at 3,000 revolutions per minute. The tool simultaneously spins in an orbit around the center of the hole, indicated by the larger orange arrow to the left.

The grinding tool is 22 millimeters (0.9 inches) in length and the actual grinding surface, which consists of the diamond pad, is 1.5 millimeters (0.06 inches) in length, indicated by the two smaller rectangles. You can see that the smaller bottom rectangle fits exactly the width of the scrape marks.

The grooves on the blueberry are also the same as the curvature of the arced pathway in which the grinding tool spins.

By overlaying appropriately scaled representations of the rock abrasion tool schematics, the evidence reveals a strong indication that the scrapes on the blueberry were induced by the tool, rather than caused by some natural geologic process.

The two rectangular boxes in the lower left and upper middle parts of this image are 'drop outs,' where the data packets inadvertently did not make it back to Earth during the initial communications relay via the Deep Space Network antennas. The missing data packets should be resent to Earth within the next few days. Just above each of the black 'drop out' rectangles is another rectangular area filled with a cluster of smaller rectangles in different shades of gray, which are image compression artifacts.

The rock abrasion tools on both Mars Exploration Rovers were supplied by Honeybee Robotics, New York, N.Y.

The use of sublaminar cables to replace Luque wires.

PubMed

Songer, M N; Spencer, D L; Meyer, P R; Jayaraman, G

1991-08-01

Sublaminar wires have been used in conjunction with posterior instrumentation to stabilize the spine. Sublaminar wiring has fallen into disfavor because of an increase in neurologic complications with the Luque technique as well as wire breakage, dural tears, and difficulty of removal. A cable system consisting of two 49-stranded stainless steel cables connected to one malleable leader was designed to overcome these shortcomings. Biomechanical testing revealed that the maximum yield strength of a single stainless steel cable loop was 2.85-2.94 times greater than a double 0.05-in. stainless steel wire loop. The fatigue tests demonstrated that the stainless steel cables required 6-22 times more cycles to failure than the stainless steel wire. Many of the titanium cables failed immediately under higher loads (0-100 lb) because of slipping of the crimp. The preliminary clinical results after a mean of 19 months of follow-up of 245 cables are encouraging. There has been no breakage or loosening of the cables and no complications associated with the use of the cables. The stainless steel cables are very strong, but more important, the cable flexibility prevents repeated contusions to the spinal cord during insertion of the rods and tightening of wires. The cable conforms to the undersurface of the lamina. This may lead to a decrease in neurologic complications.

Functional electrical stimulation controlled by artificial neural networks: pilot experiments with simple movements are promising for rehabilitation applications.

PubMed

Ferrante, Simona; Pedrocchi, Alessandra; Iannò, Marco; De Momi, Elena; Ferrarin, Maurizio; Ferrigno, Giancarlo

2004-01-01

This study falls within the ambit of research on functional electrical stimulation for the design of rehabilitation training for spinal cord injured patients. In this context, a crucial issue is the control of the stimulation parameters in order to optimize the patterns of muscle activation and to increase the duration of the exercises. An adaptive control system (NEURADAPT) based on artificial neural networks (ANNs) was developed to control the knee joint in accordance with desired trajectories by stimulating quadriceps muscles. This strategy includes an inverse neural model of the stimulated limb in the feedforward line and a neural network trained on-line in the feedback loop. NEURADAPT was compared with a linear closed-loop proportional integrative derivative (PID) controller and with a model-based neural controller (NEUROPID). Experiments on two subjects (one healthy and one paraplegic) show the good performance of NEURADAPT, which is able to reduce the time lag introduced by the PID controller. In addition, control systems based on ANN techniques do not require complicated calibration procedures at the beginning of each experimental session. After the initial learning phase, the ANN, thanks to its generalization capacity, is able to cope with a certain range of variability of skeletal muscle properties.

Assembly of barcode-like nucleic acid nanostructures.

PubMed

Wang, Pengfei; Tian, Cheng; Li, Xiang; Mao, Chengde

2014-10-15

Barcode-like (BC) nanopatterns from programmed self-assembly of nucleic acids (DNA and RNA) are reported. BC nanostructures are generated by the introduction of open spaces at selected sites to an otherwise closely packed, plain, rectangle nucleic acid nanostructure. This strategy is applied to nanostructures assembled from both origami approach and single stranded tile approach. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Generalised Multiplicative Indices of Polycyclic Aromatic Hydrocarbons and Benzenoid Systems

NASA Astrophysics Data System (ADS)

Kulli, V. R.; Stone, Branden; Wang, Shaohui; Wei, Bing

2017-05-01

Many types of topological indices such as degree-based topological indices, distance-based topological indices, and counting-related topological indices are explored during past recent years. Among degree-based topological indices, Zagreb indices are the oldest one and studied well. In the paper, we define a generalised multiplicative version of these indices and compute exact formulas for Polycyclic Aromatic Hydrocarbons and jagged-rectangle Benzenoid systems.

Domain decomposition preconditioners for the spectral collocation method

NASA Technical Reports Server (NTRS)

Quarteroni, Alfio; Sacchilandriani, Giovanni

1988-01-01

Several block iteration preconditioners are proposed and analyzed for the solution of elliptic problems by spectral collocation methods in a region partitioned into several rectangles. It is shown that convergence is achieved with a rate which does not depend on the polynomial degree of the spectral solution. The iterative methods here presented can be effectively implemented on multiprocessor systems due to their high degree of parallelism.

Area-Efficient Graph Layouts (for VLSI).

DTIC Science & Technology

1980-08-13

thle short side, then no rectangle is ew r generated x’.ho se aspect r~itho i s \\orse di ai aJ. ’I lie d i % ide-I mid -cimq tier clInt ruolIn in... Sutherland and Donald Oestrcichcr, "flow big should a printed circuit board be?," ILEEE, Transactions on Computers, Vol. C-22, May 1973, pp. 537-542. 22

21 CFR 130.14 - General statements of substandard quality and substandard fill of container.

Code of Federal Regulations, 2010 CFR

2010-04-01

... pound, the type of the first line is 12-point, and of the second, 8-point. If such quantity is 1 pound or more, the type of the first line is 14-point, and of the second, 10-point. Such statement is enclosed within lines, not less than 6 points in width, forming a rectangle. Such statement, with enclosing...

The Development of Mobile Augmented Reality

DTIC Science & Technology

2012-01-01

working jointly with NRL, performed a domain analysis ( Gabbard et al., 2002) to create a context for usability engineering effort, performed formative...rectangle to provide a background enabled the fastest user performance ( Gabbard et al., 2007). Tracking the user’s head position relative to the real...thank Yohan Baillot, Reinhold Behringer, Blaine Bell, Dennis Brown, Aaron Bryden, Enylton Coelho, Elliot Cooper-Balis, Deborah Hix, Joseph Gabbard

Practical School Experiments with the Centre of Mass of Bodies

ERIC Educational Resources Information Center

Repnik, Robert; Ambrožic, Milan

2018-01-01

The concept of the centre of mass of a rigid body as a virtual point where the weight force acts is not easy to understand without a number of supporting school experiments. In school practice, however, experiments on this topic are often limited to a few of the simplest cases in which a simple flat body, such as a triangle or rectangle, is hung…

Geometry in Early Years: Sowing Seeds for a Mathematical Definition of Squares and Rectangles

ERIC Educational Resources Information Center

Bartolini Bussi, Maria G.; Baccaglini-Frank, Anna

2015-01-01

In early years schooling it is becoming common to propose activities that involve moving along paths, or programming robots to do so. In order to promote continuity towards the introduction of geometry in primary school, we developed a long-term teaching experiment (with 15 sessions) carried out over 4 months in a first grade classroom in northern…

Constructing Geometric Properties of Rectangle, Square, and Triangle in the Third Grade of Indonesian Primary Schools

ERIC Educational Resources Information Center

Rizkianto, Ilham; Zulkardi; Darmawijaya

2013-01-01

Previous studies have provided that when learning shapes for the first time, young children tend to use the prototype as the reference point for comparisons, but often fail when doing so since they do not yet think about the defining attributes or the geometric properties of the shapes. Most of the time, elementary students learn geometric…

An efficient way of layout processing based on calibre DRC and pattern matching for defects inspection application

NASA Astrophysics Data System (ADS)

Li, Helen; Lee, Robben; Lee, Tyzy; Xue, Teddy; Liu, Hermes; Wu, Hall; Wan, Qijian; Du, Chunshan; Hu, Xinyi; Liu, Zhengfang

2018-03-01

As technology advances, escalating layout design complexity and chip size make defect inspection becomes more challenging than ever before. The YE (Yield Enhancement) engineers are seeking for an efficient strategy to ensure accuracy without suffering running time. A smart way is to set different resolutions for different pattern structures, for examples, logic pattern areas have a higher scan resolution while the dummy areas have a lower resolution, SRAM area may have another different resolution. This can significantly reduce the scan processing time meanwhile the accuracy does not suffer. Due to the limitation of the inspection equipment, the layout must be processed in order to output the Care Area marker in line with the requirement of the equipment, for instance, the marker shapes must be rectangle and the number of the rectangle shapes should be as small as possible. The challenge is how to select the different Care Areas by pattern structures, merge the areas efficiently and then partition them into pieces of rectangle shapes. This paper presents a solution based on Calibre DRC and Pattern Matching. Calibre equation-based DRC is a powerful layout processing engine and Calibre Pattern Matching's automated visual capture capability enables designers to define these geometries as layout patterns and store them in libraries which can be re-used in multiple design layouts. Pattern Matching simplifies the description of very complex relationships between pattern shapes efficiently and accurately. Pattern matching's true power is on display when it is integrated with normal DRC deck. In this application of defects inspection, we first run Calibre DRC to get rule based Care Area then use Calibre Pattern Matching's automated pattern capture capability to capture Care Area shapes which need a higher scan resolution with a tune able pattern halo. In the pattern matching step, when the patterns are matched, a bounding box marker will be output to identify the high resolution area. The equation-based DRC and Pattern Matching effectively work together for different scan phases.

Seed morphometric characteristics of European species of Elatine (Elatinaceae)

PubMed Central

Łysko, Andrzej; Białecka, Bożenna; Bihun, Magdalena Marta; Sramkó, Gábor; Staroń, Waldemar; Wieczorek, Anetta; Molnár V., Attila

2017-01-01

Elatine L. contains ca. 25 small, herbaceous, annual species distributed in ephemeral waters in both hemispheres. All species are amphibious and characterized by a high degree of morphological variability. The importance of seed morphology in Elatine taxonomy has been emphasized by many authors. The degree of seed curvature and seed coat reticulation have been traditionally considered very important in recognizing individual species of this genus. Seed morphometric characteristics of 10 Elatine species, including all European native taxa, are provided on the basis of material from two or three populations of each species. A total of 24–50 seeds were studied from each population, altogether 1,260 images were used for the morphometric study. In total, six parameters were measured from SEM pictures: object surface area, profile specific perimeter (object circuit), rectangle of the object (a) length, rectangle of the object (b) width, angle of the seed curvature, and number of pits in the seed coat counted in the middle row. Our study shows that the range of morphological variation of seeds in European species of Elatine is great, both between the species and the populations. Discrimination analysis showed that all six traits significantly differentiate the populations studied (λ = 0.001, p < 0.001), and the greatest contributions were “number of pits”, “rectangle_a”, and “the angle curvature”. Multidimensional scaling based on a correlation matrix of Mahalanobis distance of the six features studied revealed the greatest similarity between the three populations of E. alsinastrum, E. macropoda, and E. hexandra. Regarding interspecific differences, a Kruskal–Wallis tests showed that, in many cases, lack of statistically significant differences between species relative to the studied seed traits. If distinction of species is only based on seeds, especially if only a few seeds are evaluated, the following species pairs can be easily confused: E. alsinastrum and E. orthosperma, E. hexandra and E. macropoda, E. campylosperma and E. hydropiper, as well and E. gussonei and E. hungarica. We found no diversity in seed coat micromorphology within pits that could have potential taxonomic importance. An identification key and descriptions of species are provided on the basis of seeds traits. PMID:28584724

Self assembly of rectangular shapes on concentration programming and probabilistic tile assembly models.

PubMed

Kundeti, Vamsi; Rajasekaran, Sanguthevar

2012-06-01

Efficient tile sets for self assembling rectilinear shapes is of critical importance in algorithmic self assembly. A lower bound on the tile complexity of any deterministic self assembly system for an n × n square is [Formula: see text] (inferred from the Kolmogrov complexity). Deterministic self assembly systems with an optimal tile complexity have been designed for squares and related shapes in the past. However designing [Formula: see text] unique tiles specific to a shape is still an intensive task in the laboratory. On the other hand copies of a tile can be made rapidly using PCR (polymerase chain reaction) experiments. This led to the study of self assembly on tile concentration programming models. We present two major results in this paper on the concentration programming model. First we show how to self assemble rectangles with a fixed aspect ratio ( α:β ), with high probability, using Θ( α + β ) tiles. This result is much stronger than the existing results by Kao et al. (Randomized self-assembly for approximate shapes, LNCS, vol 5125. Springer, Heidelberg, 2008) and Doty (Randomized self-assembly for exact shapes. In: proceedings of the 50th annual IEEE symposium on foundations of computer science (FOCS), IEEE, Atlanta. pp 85-94, 2009)-which can only self assembly squares and rely on tiles which perform binary arithmetic. On the other hand, our result is based on a technique called staircase sampling . This technique eliminates the need for sub-tiles which perform binary arithmetic, reduces the constant in the asymptotic bound, and eliminates the need for approximate frames (Kao et al. Randomized self-assembly for approximate shapes, LNCS, vol 5125. Springer, Heidelberg, 2008). Our second result applies staircase sampling on the equimolar concentration programming model (The tile complexity of linear assemblies. In: proceedings of the 36th international colloquium automata, languages and programming: Part I on ICALP '09, Springer-Verlag, pp 235-253, 2009), to self assemble rectangles (of fixed aspect ratio) with high probability. The tile complexity of our algorithm is Θ(log( n )) and is optimal on the probabilistic tile assembly model (PTAM)- n being an upper bound on the dimensions of a rectangle.

IFT46 plays an essential role in cilia development

PubMed Central

Lee, Mi-Sun; Hwang, Kyu-Seok; Oh, Hyun-Woo; Ji-Ae, Kim; Kim, Hyun-Taek; Cho, Hyun-Soo; Lee, Jeong-Ju; Ko, Je Yeong; Choi, Jung-Hwa; Jeong, Yun-Mi; You, Kwan-Hee; Kim, Joon; Park, Doo-Sang; Nam, Ki-Hoan; Aizawa, Shinichi; Kiyonari, Hiroshi; Shioi, Go; Park, Jong-Hoon; Zhou, Weibin; Kim, Nam-Soon; Kim, Cheol-Hee

2015-01-01

Cilia are microtubule-based structures that project into the extracellular space. Ciliary defects are associated with several human diseases, including polycystic kidney disease, primary ciliary dyskinesia, left-right axis patterning, hydrocephalus and retinal degeneration. However, the genetic and cellular biological control of ciliogenesis remains poorly understood. The IFT46 is one of the highly conserved intraflagellar transport complex B proteins. In zebrafish, ift46 is expressed in various ciliated tissues such as Kupffer’s vesicle, pronephric ducts, ears and spinal cord. We show that ift46 is localized to the basal body. Knockdown of ift46 gene results in multiple phenotypes associated with various ciliopathies including kidney cysts, pericardial edema and ventral axis curvature. In ift46 morphants, cilia in kidney and spinal canal are shortened and abnormal. Similar ciliary defects are observed in otic vesicles, lateral line hair cells, olfactory pits, but not in Kupffer’s vesicle. To explore the functions of Ift46 during mouse development, we have generated Ift46 knock-out mice. The Ift46 mutants have developmental defects in brain, neural tube and heart. In particular Ift46(−/−) homozygotes displays randomization of the embryo heart looping, which is a hallmark of defective left-right (L/R) axis patterning. Taken together, our results demonstrated that IFT46 has an essential role in vertebrate ciliary development. PMID:25722189

Adaptive, fast walking in a biped robot under neuronal control and learning.

PubMed

Manoonpong, Poramate; Geng, Tao; Kulvicius, Tomas; Porr, Bernd; Wörgötter, Florentin

2007-07-01

Human walking is a dynamic, partly self-stabilizing process relying on the interaction of the biomechanical design with its neuronal control. The coordination of this process is a very difficult problem, and it has been suggested that it involves a hierarchy of levels, where the lower ones, e.g., interactions between muscles and the spinal cord, are largely autonomous, and where higher level control (e.g., cortical) arises only pointwise, as needed. This requires an architecture of several nested, sensori-motor loops where the walking process provides feedback signals to the walker's sensory systems, which can be used to coordinate its movements. To complicate the situation, at a maximal walking speed of more than four leg-lengths per second, the cycle period available to coordinate all these loops is rather short. In this study we present a planar biped robot, which uses the design principle of nested loops to combine the self-stabilizing properties of its biomechanical design with several levels of neuronal control. Specifically, we show how to adapt control by including online learning mechanisms based on simulated synaptic plasticity. This robot can walk with a high speed (>3.0 leg length/s), self-adapting to minor disturbances, and reacting in a robust way to abruptly induced gait changes. At the same time, it can learn walking on different terrains, requiring only few learning experiences. This study shows that the tight coupling of physical with neuronal control, guided by sensory feedback from the walking pattern itself, combined with synaptic learning may be a way forward to better understand and solve coordination problems in other complex motor tasks.

Post-traumatic delayed onset pectoralis myospasm secondary to α-γ dysfunction

PubMed Central

Barnett, Dennis L; McGhee, Klinton; Bungee, Paul

2013-01-01

A restrained motor vehicle accident victim suffered from delayed onset left pectoralis myospasms refractory to multiple treatments: behavioural, conservative, physical therapy, opiate, muscle relaxer and incomplete response to invasive pain management spinal blocks. After conduction of a literature review, several authors had noted the mechanism of α-γ loop dysfunction resulting in myospams, and also case studies which described painful postsurgical myospasms that were treated with neurectomy and/or botulinum toxin A with successful results. The patient in this case underwent an initial lidocaine injection to observe response to treatment, followed by two treatments with botulinum toxin A treatment with subsequent resolution of symptoms. Successful therapy and previous research supports that botulinum toxin A can be an effective treatment for myospasms secondary to trauma-induced α-γ dysfunction, as suggested by the cellular pathophysiology. PMID:23814192

Compliant Robot Wrist

NASA Technical Reports Server (NTRS)

Voellmer, George

1992-01-01

Compliant element for robot wrist accepts small displacements in one direction only (to first approximation). Three such elements combined to obtain translational compliance along three orthogonal directions, without rotational compliance along any of them. Element is double-blade flexure joint in which two sheets of spring steel attached between opposing blocks, forming rectangle. Blocks moved parallel to each other in one direction only. Sheets act as double cantilever beams deforming in S-shape, keeping blocks parallel.

Screen Time, How Much Is Too Much? The Social and Emotional Costs of Technology on the Adolescent Brain

ERIC Educational Resources Information Center

DeWeese, Katherine Lynn

2014-01-01

Screen time no longer means just the amount of time one spends in front of the television. Now it is an aggregate amount of time spent on smartphones, computers as well as multitasking with different devices. How much are the glowing rectangles taking away from adolescent social and emotional health? How is it changing how students learn and how…

Particle Shape and Composition of NU-LHT-2M

NASA Technical Reports Server (NTRS)

Rickman, D. L.; Lowers, H.

2012-01-01

Particle shapes of the lunar regolith simulant NU-LHT-2M were analyzed by scanning electron microscope of polished sections. These data provide shape, size, and composition information on a particle by particle basis. 5,193 particles were measured, divided into four sized fractions: less than 200 mesh, 200-100 mesh, 100-35 mesh, and greater than 35 mesh. 99.2% of all particles were monominerallic. Minor size versus composition effects were noted in minor and trace mineralogy. The two metrics used are aspect ratio and Heywood factor, plotted as normalized frequency distributions. Shape versus composition effects were noted for glass and possibly chlorite. To aid in analysis, the measured shape distributions are compared to data for ellipses and rectangles. Several other simple geometric shapes are also investigated as to how they plot in aspect ratio versus Heywood factor space. The bulk of the data previously reported, which were acquired in a plane of projection, are between the ellipse and rectangle lines. In contrast, these data, which were acquired in a plane of section, clearly show that a significant number of particles have concave hulls in this view. Appendices cover details of measurement error, use of geometric shapes for comparative analysis, and a logic for comparing data from plane of projection and plane of section measurements.

Spreading of non-planar non-axisymmetric gravity and turbidity currents

NASA Astrophysics Data System (ADS)

Zgheib, Nadim; Bonometti, Thomas; Balachandar, S.

2014-11-01

The dynamics of non-axisymmetric turbidity currents is considered here. The study comprises a series of experiments for which a finite volume of particle-laden solution is released into fresh water. A mixture of water and polystyrene particles of diameter 280

Object width modulates object-based attentional selection.

PubMed

Nah, Joseph C; Neppi-Modona, Marco; Strother, Lars; Behrmann, Marlene; Shomstein, Sarah

2018-04-24

Visual input typically includes a myriad of objects, some of which are selected for further processing. While these objects vary in shape and size, most evidence supporting object-based guidance of attention is drawn from paradigms employing two identical objects. Importantly, object size is a readily perceived stimulus dimension, and whether it modulates the distribution of attention remains an open question. Across four experiments, the size of the objects in the display was manipulated in a modified version of the two-rectangle paradigm. In Experiment 1, two identical parallel rectangles of two sizes (thin or thick) were presented. Experiments 2-4 employed identical trapezoids (each having a thin and thick end), inverted in orientation. In the experiments, one end of an object was cued and participants performed either a T/L discrimination or a simple target-detection task. Combined results show that, in addition to the standard object-based attentional advantage, there was a further attentional benefit for processing information contained in the thick versus thin end of objects. Additionally, eye-tracking measures demonstrated increased saccade precision towards thick object ends, suggesting that Fitts's Law may play a role in object-based attentional shifts. Taken together, these results suggest that object-based attentional selection is modulated by object width.

Thresholds of cortical activation of muscle spindles and α motoneurones of the baboon's hand

PubMed Central

Koeze, T. H.; Phillips, C. G.; Sheridan, J. D.

1968-01-01

1. Much current thinking about voluntary movement assumes that the segmental γ loops can function as a servomechanism operated by the brain. However, the α motoneurones of the baboon's hand receive a powerful monosynaptic (CM) projection from the precentral gyrus. If servo-driving from the same cortical area is to be possible, it must project independently to the fusimotor neurones and have sufficient power to increase the afferent signalling from the muscle spindles. The cortical thresholds for contraction of m. extensor digitorum communis and for acceleration of the discharges of its muscle spindles have therefore been compared. 2. Significant results in this context require that the spindles studied be coupled in parallel with the responding extrafusal muscle fibres. Many spindles were not unloaded by the submaximal contractions evoked by cortical stimulation, although all so tested were unloaded by maximal motor nerve twitches. Reasons are given for thinking that such apparent lack of parallel coupling is an artifact of complex intramuscular anatomy and limitation of shortening by `isometric' myography. 3. A brief burst of corticospinal volleys at 500/sec, which is specially effective in exciting α motoneurones over the CM projection, failed to excite spindle afferents at or below the threshold for a cortical `twitch'. 4. In a few epileptiform discharges, bursts of spindle acceleration occurred independently of the clonic contractions. A relatively direct and independent cortico-fusimotor (CF) projection may therefore exist. 5. Prolonged near-threshold stimulation at 50-100/sec, which allows time for temporal summation in the less direct projections (e.g. cortico-interneuronal, cortico-rubro-spinal) and does not cause frequency-potentiation at CM synapses, gives abundant evidence of independent α and fusimotor projections, whose actions hardly outlast the stimulation period. 6. Although independent CF projections would permit servo-driving in natural movements of the hand (given adequate loop gain), there has been no evidence of servo-driving by cortical stimulation or in the spontaneous contractions of light anaesthesia. 7. Independent projections would provide for controlled αγ co-excitation in the servo-governing of natural movements (Matthews, 1964). 8. Evidence is reviewed that the CM projection itself may be part of an important control loop for voluntary movement in primates. A corollary would be a diminished importance of CF projections for segmental loops and an increased importance for maintaining the spindle input to cortical loops. PMID:4231033

Closed-loop double-vasopressor automated system vs manual bolus vasopressor to treat hypotension during spinal anaesthesia for caesarean section: a randomised controlled trial.

PubMed

Sng, B L; Tan, H S; Sia, A T H

2014-01-01

Hypotension necessitating vasopressor administration occurs commonly during caesarean section under spinal anaesthesia. We developed a novel vasopressor delivery system that automatically administers phenylephrine or ephedrine based on continuous non-invasive arterial pressure monitoring. A phenylephrine bolus of 50 μg was given at 30-s intervals when systolic blood pressure fell < 90% of baseline; an ephedrine bolus of 4 mg was given instead if systolic pressure fell < 90% of baseline together with a heart rate < 60 beats.min(-1). The control group used manual boluses of either phenylephrine 100 μg or ephedrine 8 mg, administered at 1-min intervals based on the same thresholds for systolic pressure and heart rate. This randomised, controlled, double-blinded trial involved 213 healthy women who underwent elective caesarean delivery under spinal anaesthesia using 11 mg hyperbaric bupivacaine with 15 μg fentanyl and 100 μg morphine. The automated vasopressor group had better systolic pressure control, with 37/106 (34.9%) having any beat-to-beat systolic pressure reading < 80% of baseline compared with 63/107 (58.9%) in the control group (p < 0.001). There was no difference in the incidence of reactive hypertension, defined as systolic pressure > 120% of baseline, with 8/106 (7.5%) in the automated vasopressor group vs 14/107 (13.1%) in the control group, or total dose of vasopressors. The automated vasopressor group had lower median absolute performance error of 8.5% vs control of 9.8% (p = 0.013), and reduced incidence of nausea (1/106 (0.9%) vs 11/107 (10.3%), p = 0.005). Neonatal umbilical cord pH, umbilical lactate and Apgar scores were similar. Hence, our system afforded better control of maternal blood pressure and reduced nausea with no increase in reactive hypertension when compared with manual boluses. © 2013 The Association of Anaesthetists of Great Britain and Ireland.

TSARINA: User’s Guide to a Computer Model for Damage Assessment of Complex Airbase Targets.

DTIC Science & Technology

1980-07-01

IF WITHIN RECTANGLE ENCLOSING PATTERN THAT IS PAPOLLTL TO 2018 . C AXES 2019. IF ((IT *L T . 1(1)).OR. (IT *GT. 1(3))) GO TO 3𔃻 2020. IF ((IT *LT. Y...1H /I¥/ 1H+ /,IS/ I- /,IE/ IN’ / 21)9. C THIS BOUTINE PLOTS THE IMPACT POINTS (BUT NOT CRATEPS) POE 2110. C ALL "ITS THAT HAVE BEEN STORED FOR A

Physiological Monitoring in Diving Mammals

DTIC Science & Technology

2015-09-30

obtain the required 70 MHz sine wave, we instead created a 10 MHz rectangle pulse wave and used a 70 MHz band pass filter (KR electronics 2657 sma) to...animals (Table 1) were sedated on the beach and transported to Long Marine Laboratory where the data logger was attached and the oximeter sensor...implanted under injectable sedation. In addition, the implantation procedure of the oximeter was assessed and we carefully noted any indications of trauma

Supply Chain Modeling for Fluorspar and Hydrofluoric Acid and Implications for Further Analyses

DTIC Science & Technology

2015-04-01

Supply Other usesUS Supply Fluorspar Mining HF Production Downstream Products Stages of Production Other uses “Upstream” Supply and Demand...chain, as follows: • The three stages of the chain considered in the analysis are listed across the top: Fluorspar Mining , HF Production, and (pro...consumption of HF is represented by the maroon rectangle. • The lines depict material flows from fluorspar mining , to HF production, to downstream fluorine

Developing Novel Frameworks for Many-Body Ensembles

DTIC Science & Technology

2016-03-17

RETURN YOUR FORM TO THE ABOVE ADDRESS. Massachusetts Institute of Technology (MIT) 77 Massachusetts Ave. NE18-901 Cambridge , MA 02139 -4307 15-Jul-2015...of-equilibrium dynamics and to estimate prob- Page 4 of 9 Figure 2: Illustration of the dendro- gram representation. The rectangle on the left shows...isolation as illustrated in Figure 4. Starting from random initial conditions, an ensemble of particle pairs was simulated to establish the long-time

Louisville, KY, USA

NASA Technical Reports Server (NTRS)

1973-01-01

The meandering Ohio River bisecting this image is the border between Kentucky and Indiana. Louisville, KY (38.5N, 86.0W) on the south shore, is the main city seen in this predominately agricultural region where much of the native hardwood forests have been preserved in the hilly terrain. The main crops in this region include corn, alfalfa, wheat and soybeans. The dark rectangle in south Indiana near the river is The U.S. Army's Jefferson Proving Ground.

Fourier analysis of the SOR iteration

NASA Technical Reports Server (NTRS)

Leveque, R. J.; Trefethen, L. N.

1986-01-01

The SOR iteration for solving linear systems of equations depends upon an overrelaxation factor omega. It is shown that for the standard model problem of Poisson's equation on a rectangle, the optimal omega and corresponding convergence rate can be rigorously obtained by Fourier analysis. The trick is to tilt the space-time grid so that the SOR stencil becomes symmetrical. The tilted grid also gives insight into the relation between convergence rates of several variants.

A model of cerebrocerebello-spinomuscular interaction in the sagittal control of human walking.

PubMed

Jo, Sungho; Massaquoi, Steve G

2007-03-01

A computationally developed model of human upright balance control (Jo and Massaquoi on Biol cybern 91:188-202, 2004) has been enhanced to describe biped walking in the sagittal plane. The model incorporates (a) non-linear muscle mechanics having activation level -dependent impedance, (b) scheduled cerebrocerebellar interaction for control of center of mass position and trunk pitch angle, (c) rectangular pulse-like feedforward commands from a brainstem/ spinal pattern generator, and (d) segmental reflex modulation of muscular synergies to refine inter-joint coordination. The model can stand when muscles around the ankle are coactivated. When trigger signals activate, the model transitions from standing still to walking at 1.5 m/s. Simulated natural walking displays none of seven pathological gait features. The model can simulate different walking speeds by tuning the amplitude and frequency in spinal pattern generator. The walking is stable against forward and backward pushes of up to 70 and 75 N, respectively, and with sudden changes in trunk mass of up to 18%. The sensitivity of the model to changes in neural parameters and the predicted behavioral results of simulated neural system lesions are examined. The deficit gait simulations may be useful to support the functional and anatomical correspondences of the model. The model demonstrates that basic human-like walking can be achieved by a hierarchical structure of stabilized-long loop feedback and synergy-mediated feedforward controls. In particular, internal models of body dynamics are not required.

System characterization of RiceWrist-S: a forearm-wrist exoskeleton for upper extremity rehabilitation.

PubMed

Pehlivan, Ali Utku; Rose, Chad; O'Malley, Marcia K

2013-06-01

Rehabilitation of the distal joints of the upper extremities is crucial to restore the ability to perform activities of daily living to patients with neurological lesions resulting from stroke or spinal cord injury. Robotic rehabilitation has been identified as a promising new solution, however, much of the existing technology in this field is focused on the more proximal joints of the upper arm. A recently presented device, the RiceWrist-S, focuses on the rehabilitation of the forearm and wrist, and has undergone a few important design changes. This paper first addresses the design improvements achieved in the recent design iteration, and then presents the system characterization of the new device. We show that the RiceWrist-S has capabilities beyond other existing devices, and exhibits favorable system characteristics as a rehabilitation device, in particular torque output, range of motion, closed loop position performance, and high spatial resolution.

Evidence for a Role of the Transcriptional Regulator Maid in Tumorigenesis and Aging

PubMed Central

Fujisawa, Koichi; Terai, Shuji; Matsumoto, Toshihiko; Takami, Taro; Yamamoto, Naoki; Nishina, Hiroshi; Furutani-Seiki, Makoto; Sakaida, Isao

2015-01-01

Maid is a helix-loop-helix protein that is involved in cell proliferation. In order to further elucidate its physiological functions, we studied Maid activity in two small fish model systems. We found that Maid expression was greatest in zebrafish liver and that it increased following partial hepatectomy. Maid levels were also high in hepatic preneoplastic foci induced by treatment of zebrafish with diethylnitrosamine (DEN), but low in hepatocellular carcinomas (HCC), mixed tumors, and cholangiocarcinomas developing in these animals. In DEN-treated transgenic medaka overexpressing Maid, hepatic BrdU uptake and proliferation were reduced. After successive breedings, Maid transgenic medaka exhibited decreased movement and a higher incidence of abnormal spine curvature, possibly due to the senescence of spinal cord cells. Taken together, our results suggest that Maid levels can influence the progression of liver cancer. In conclusion, we found that Maid is important regulator of hepatocarconogenesis and aging. PMID:26107180

Self assembly of rectangular shapes on concentration programming and probabilistic tile assembly models

PubMed Central

Rajasekaran, Sanguthevar

2013-01-01

Efficient tile sets for self assembling rectilinear shapes is of critical importance in algorithmic self assembly. A lower bound on the tile complexity of any deterministic self assembly system for an n × n square is Ω(log(n)log(log(n))) (inferred from the Kolmogrov complexity). Deterministic self assembly systems with an optimal tile complexity have been designed for squares and related shapes in the past. However designing Θ(log(n)log(log(n))) unique tiles specific to a shape is still an intensive task in the laboratory. On the other hand copies of a tile can be made rapidly using PCR (polymerase chain reaction) experiments. This led to the study of self assembly on tile concentration programming models. We present two major results in this paper on the concentration programming model. First we show how to self assemble rectangles with a fixed aspect ratio (α:β), with high probability, using Θ(α + β) tiles. This result is much stronger than the existing results by Kao et al. (Randomized self-assembly for approximate shapes, LNCS, vol 5125. Springer, Heidelberg, 2008) and Doty (Randomized self-assembly for exact shapes. In: proceedings of the 50th annual IEEE symposium on foundations of computer science (FOCS), IEEE, Atlanta. pp 85–94, 2009)—which can only self assembly squares and rely on tiles which perform binary arithmetic. On the other hand, our result is based on a technique called staircase sampling. This technique eliminates the need for sub-tiles which perform binary arithmetic, reduces the constant in the asymptotic bound, and eliminates the need for approximate frames (Kao et al. Randomized self-assembly for approximate shapes, LNCS, vol 5125. Springer, Heidelberg, 2008). Our second result applies staircase sampling on the equimolar concentration programming model (The tile complexity of linear assemblies. In: proceedings of the 36th international colloquium automata, languages and programming: Part I on ICALP ’09, Springer-Verlag, pp 235–253, 2009), to self assemble rectangles (of fixed aspect ratio) with high probability. The tile complexity of our algorithm is Θ(log(n)) and is optimal on the probabilistic tile assembly model (PTAM)—n being an upper bound on the dimensions of a rectangle. PMID:24311993

Coding and Flow Charting as Applied to UICSM Programed Texts (1962-1963 Versions). Comparative Studies of Principles for Programming Mathematics in Automated Instruction. Technical Report.

ERIC Educational Resources Information Center

Stolurow, Lawrence M.; And Others

Coding systems need to be developed to account for computer decisions on every frame of a self-instructional program. In flow charts of the UICSM high school math programed series, each frame or page is represented by a diagramatic convention: diamond if a mainline frame, a rectangle if a quiz frame, a bottom-heavy trapezoid if a review or…

Self-recognition in the coordination driven self-assembly of 2-D polygons.

PubMed

Addicott, Chris; Das, Neeladri; Stang, Peter J

2004-08-23

Self-recognition in the transition-metal-mediated self-assembly of some 2-D polygons is presented. Prolonged heating of two or three organoplatinum reagents with 4,4'-dipyridyl in aqueous acetone results in the predominant formation of a rectangle, triangle, and/or square. All mixtures are characterized with NMR and electrospray ionization mass spectrometry (ESIMS). Despite the potential for ill-defined oligomeric products, these mixed ligand systems prefer to self-assemble into discrete species.

Seeing tones and hearing rectangles - Attending to simultaneous auditory and visual events

NASA Technical Reports Server (NTRS)

Casper, Patricia A.; Kantowitz, Barry H.

1985-01-01

The allocation of attention in dual-task situations depends on both the overall and the momentary demands associated with both tasks. Subjects in an inclusive- or reaction-time task responded to changes in simultaneous sequences of discrete auditory and visual stimuli. Performance on individual trials was affected by (1) the ratio of stimuli in the two tasks, (2) response demands of the two tasks, and (3) patterns inherent in the demands of one task.

Statistics of Radial Ship Extent as Seen by a Seeker

DTIC Science & Technology

2014-06-01

Auckland in pure and applied mathematics and physics, and a Master of Science in physics from the same university with a thesis in applied accelerator...does not demand contributions from two angle bins to one extent bin, unlike the rectangle; this is a very big advantage of the ellipse model. However...waveform that mimics the full length of a ship. This allows more economical use to be made of available false-target generation resources. I wish to

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

Jadav, Mudra; Patel, Rajesh, E-mail: rjp@mkbhavuni.edu.in, E-mail: rpat7@yahoo.co

Here we present a technique using magnetic nanofluid to induce bidispersed suspension of nonmagnetic particles to assemble into colloidal chain, triangle, rectangle, ring-flower configurations. By changing the amplitude and direction of the magnetic field, we could tune the structure of nonmagnetic particles in magnetic nanofluid. The structures are assembled using magneto static interactions between effectively nonmagnetic particles dispersed in magnetizable magnetic nanofluid. The assembly of complex structures out of simple colloidal building blocks is of practical interest in photonic crystals and DNA biosensors.

Development of Nano Plasmonic Structures for Multispectral IR Filters

DTIC Science & Technology

the polarization is parallel to the short ridge of the rectangle hole, it yields high optical transmission. The hole aspects are very important to the...Cross-shaped-hole arrays (CSHAs) are selected3 to diminish the polarization-dependent transmission differences of incident plane waves. The transmission...for the CSHA are set to 280nm and 50nm for period of 350nm, respectively; and the thicknesses of the metal films are set to 100nm. We varied the

Stochastic and Simulation Models of Maritime Intercept Operations Capabilities

DTIC Science & Technology

2005-12-01

methods of operations research. 2 Furusawa , Tadahiko, “On Territorial Defense – Policing Sea Area...searches a rectangle region AOI with area x yM M ⋅ . The MPA travels the AOI at a speed v . The radar coverage or radar footprint is assumed to be a...Borges, Jose Manuel, “Radar Search and Detection with the CASA 212 S43 Aircraft,” Naval Postgraduate School, (2004) 17 whole AOI is ( ) 2/x yM M f

Sensor Phenomenology and Feature Development for Improved Sonar-based Detection & Classification of Underwater UXO

DTIC Science & Technology

2009-12-01

the validity of approximating poroelastic media with acoustic or acoustic /elastic models , and to characterize how scattering physics will differ for...elastic buried object (yellow rectangle in the figure) in three types of environments: • (1) Model 1: acoustic layer on top of a poroelastic medium with a...porosity gradient and no viscous damping. • (2) Model 2: acoustic layer on top of a poroelastic medium with a porosity gradient and viscous damping

Focused Ion Beam Fabrication of Microelectronic Structures

DTIC Science & Technology

1990-12-01

a simple function generator and allows fast ing, the pressure measured by the capacitance manometer is equal to the pressure at the sample surface...height above the sample ties. In practice this restricts features to simple rectangles or surface. J. Vac. . Tedhnol. B, VOL 7, No. 4, Jul/Aug IM...the sample up to 300 keV are available.(2) -3- This higher energy is often needed for implantation and for lithography in thick resist. Be++ ions at

Combining Image Processing with Signal Processing to Improve Transmitter Geolocation Estimation

DTIC Science & Technology

2014-03-27

transmitter by searching a grid of possible transmitter locations within the image region. At each evaluated grid point, theoretical TDOA values are computed...requires converting the image to a grayscale intensity image. This allows efficient manipulation of data and ease of comparison among pixel values . The...cluster of redundant y values along the top edge of an ideal rectangle. The same is true for the bottom edge, as well as for the x values along the

Sensemaking of Narratives: Informing the Capabilities Development Process

DTIC Science & Technology

2014-06-01

experiences. Narratives provide meaning across a wide range of disciplines, particularly from the fields of social sciences, such as anthropology and...stated that the GBOSS ―helped the civilians on the blimp to coordinate with us when we‘d find a smoke cloud and they could get eyes on it when we...Radar (STS-1400) menu in the tree view (left side of the screen displaying all of the sensors available to each system) and ensure the colored rectangle

Novel Techniques for Characterizing and Understanding the Response of Rubbers and Rubber-Based Composites to Impact Loading

DTIC Science & Technology

2016-09-30

4 of 42 Figure 9. Left: Schematic representation of the gas -gun experiment and a typical speckle pattern the specimen surface, the 12...12 correlation window used in subsequent analysis is also indicated (red rectangle). Right: a photograph of the gas -gun system...20 Figure 11. Left: Averaged acceleration and strain rate and history of μ and α prediction from gas -gun experiment on an EPDM specimen

Multiple-Valued Programmable Logic Array Minimization by Simulated Annealing

DTIC Science & Technology

1992-02-10

time is controllable, allowing one to tradeoff time for minimalit ’. It has been incorporated in the HAMLET PLA minimization tool. AcOSSIOn P? DTTC TAB C...specified along the horizontal axis. Each slice represents one temperature. The slice in the very front represents the highest and starting ...rectangle with a pair of adjacent 2’s in between. This func- tion can yield five product terms by a sequence of reshape moves starting from four

The research of knitting needle status monitoring setup

NASA Astrophysics Data System (ADS)

Liu, Lu; Liao, Xiao-qing; Zhu, Yong-kang; Yang, Wei; Zhang, Pei; Zhao, Yong-kai; Huang, Hui-jie

2013-09-01

In textile production, quality control and testing is the key to ensure the process and improve the efficiency. Defect of the knitting needles is the main factor affecting the quality of the appearance of textiles. Defect detection method based on machine vision and image processing technology is universal. This approach does not effectively identify the defect generated by damaged knitting needles and raise the alarm. We developed a knitting needle status monitoring setup using optical imaging, photoelectric detection and weak signal processing technology to achieve real-time monitoring of weaving needles' position. Depending on the shape of the knitting needle, we designed a kind of Glass Optical Fiber (GOF) light guides with a rectangular port used for transmission of the signal light. To be able to capture the signal of knitting needles accurately, we adopt a optical 4F system which has better imaging quality and simple structure and there is a rectangle image on the focal plane after the system. When a knitting needle passes through position of the rectangle image, the reflected light from needle surface will back to the GOF light guides along the same optical system. According to the intensity of signals, the computer control unit distinguish that the knitting needle is broken or curving. The experimental results show that this system can accurately detect the broken needles and the curving needles on the knitting machine in operating condition.

Image Processing of Porous Silicon Microarray in Refractive Index Change Detection.

PubMed

Guo, Zhiqing; Jia, Zhenhong; Yang, Jie; Kasabov, Nikola; Li, Chuanxi

2017-06-08

A new method for extracting the dots is proposed by the reflected light image of porous silicon (PSi) microarray utilization in this paper. The method consists of three parts: pretreatment, tilt correction and spot segmentation. First, based on the characteristics of different components in HSV (Hue, Saturation, Value) space, a special pretreatment is proposed for the reflected light image to obtain the contour edges of the array cells in the image. Second, through the geometric relationship of the target object between the initial external rectangle and the minimum bounding rectangle (MBR), a new tilt correction algorithm based on the MBR is proposed to adjust the image. Third, based on the specific requirements of the reflected light image segmentation, the array cells are segmented into dots as large as possible and the distance between the dots is equal in the corrected image. Experimental results show that the pretreatment part of this method can effectively avoid the influence of complex background and complete the binarization processing of the image. The tilt correction algorithm has a shorter computation time, which makes it highly suitable for tilt correction of reflected light images. The segmentation algorithm makes the dots in a regular arrangement, excludes the edges and the bright spots. This method could be utilized in the fast, accurate and automatic dots extraction of the PSi microarray reflected light image.

Saccade Latency Indexes Exogenous and Endogenous Object-Based Attention

PubMed Central

Şentürk, Gözde; Greenberg, Adam S.; Liu, Taosheng

2016-01-01

Classic studies of object-based attention have utilized keypress responses as the main dependent measure. However, people typically make saccades to fixate important objects. Recent work has shown that attention may act differently when deployed covertly versus in advance of a saccade. We further investigated the link between saccades and attention by examining whether object-based effects can be observed for saccades. We adapted the classical double-rectangle cueing paradigm of Egly et al., (1994), and measured both the first saccade latency and keypress reaction time (RT) to a target that appeared at the end of one of the two rectangles. Our results showed that saccade latency exhibited higher sensitivity than RT in detecting effects of attention. We also assessed the generality of the attention effects by testing three types of cues: hybrid (predictive and peripheral), exogenous (non-predictive and peripheral), and endogenous (predictive and central). We found that both RT and saccade latency exhibited effects of both space-based and object-based attentional selection. However, saccade latency showed a more robust attentional modulation than RTs. For the exogenous cue, we observed a spatial inhibition-of-return along with an object-based effect, implying that object-based attention is independent of space-based attention. Overall, our results reveal an oculomotor correlate of object-based attention, suggesting that, in addition to spatial priority, object-level priority also affects saccade planning. PMID:27225468

Heat transfer enhancement and pumping power optimization using CuO-water nanofluid through rectangular corrugated pipe

NASA Astrophysics Data System (ADS)

Salehin, Musfequs; Ehsan, Mohammad Monjurul; Islam, A. K. M. Sadrul

2017-06-01

Heat transfer enhancement by corrugation in fluid domain is a popular method. The rate of improvement is more when it is used highly thermal conductive fluid as heating or cooling medium. In this present study, heat transfer augmentation was investigated numerically by implementing corrugation in the fluid domain and nanofluid as the base fluid in the turbulent forced convection regime. Finite volume method (FVM) was applied to solve the continuity, momentum and energy equations. All the numerical simulations were considered for single phase flow. A rectangle corrugated pipe with 5000 W/m2 constant heat flux subjected to the corrugated wall was considered as the fluid domain. In the range of Reynolds number 15000 to 40000, thermo-physical and hydrodynamic behavior was investigated by using CuO-water nanofluid from 1% to 5% volume fraction as the base fluid through the corrugated fluid domain. Corrugation justification was performed by changing the amplitude of the corrugation and the corrugation wave length for obtaining the increased heat transfer rate with minimum pumping power. For using CuO-water nanofluid, augmentation was also found more in the rectangle corrugated pipe both in heat transfer and pumping power requirement with the increase of Reynolds number and the volume fraction of nanofluid. For the increased pumping power, optimization of pumping power by using nanofluid was also performed for economic finding.

Solving da Vinci stereopsis with depth-edge-selective V2 cells

PubMed Central

Assee, Andrew; Qian, Ning

2007-01-01

We propose a new model for da Vinci stereopsis based on a coarse-to-fine disparity-energy computation in V1 and disparity-boundary-selective units in V2. Unlike previous work, our model contains only binocular cells, relies on distributed representations of disparity, and has a simple V1-to-V2 feedforward structure. We demonstrate with random dot stereograms that the V2 stage of our model is able to determine the location and the eye-of-origin of monocularly occluded regions and improve disparity map computation. We also examine a few related issues. First, we argue that since monocular regions are binocularly defined, they cannot generally be detected by monocular cells. Second, we show that our coarse-to-fine V1 model for conventional stereopsis explains double matching in Panum’s limiting case. This provides computational support to the notion that the perceived depth of a monocular bar next to a binocular rectangle may not be da Vinci stereopsis per se (Gillam et al., 2003). Third, we demonstrate that some stimuli previously deemed invalid have simple, valid geometric interpretations. Our work suggests that studies of da Vinci stereopsis should focus on stimuli more general than the bar-and-rectangle type and that disparity-boundary-selective V2 cells may provide a simple physiological mechanism for da Vinci stereopsis. PMID:17698163

A distributed air index based on maximum boundary rectangle over grid-cells for wireless non-flat spatial data broadcast.

PubMed

Im, Seokjin; Choi, JinTak

2014-06-17

In the pervasive computing environment using smart devices equipped with various sensors, a wireless data broadcasting system for spatial data items is a natural way to efficiently provide a location dependent information service, regardless of the number of clients. A non-flat wireless broadcast system can support the clients in accessing quickly their preferred data items by disseminating the preferred data items more frequently than regular data on the wireless channel. To efficiently support the processing of spatial window queries in a non-flat wireless data broadcasting system, we propose a distributed air index based on a maximum boundary rectangle (MaxBR) over grid-cells (abbreviated DAIM), which uses MaxBRs for filtering out hot data items on the wireless channel. Unlike the existing index that repeats regular data items in close proximity to hot items at same frequency as hot data items in a broadcast cycle, DAIM makes it possible to repeat only hot data items in a cycle and reduces the length of the broadcast cycle. Consequently, DAIM helps the clients access the desired items quickly, improves the access time, and reduces energy consumption. In addition, a MaxBR helps the clients decide whether they have to access regular data items or not. Simulation studies show the proposed DAIM outperforms existing schemes with respect to the access time and energy consumption.

Image Processing of Porous Silicon Microarray in Refractive Index Change Detection

PubMed Central

Guo, Zhiqing; Jia, Zhenhong; Yang, Jie; Kasabov, Nikola; Li, Chuanxi

2017-01-01

A new method for extracting the dots is proposed by the reflected light image of porous silicon (PSi) microarray utilization in this paper. The method consists of three parts: pretreatment, tilt correction and spot segmentation. First, based on the characteristics of different components in HSV (Hue, Saturation, Value) space, a special pretreatment is proposed for the reflected light image to obtain the contour edges of the array cells in the image. Second, through the geometric relationship of the target object between the initial external rectangle and the minimum bounding rectangle (MBR), a new tilt correction algorithm based on the MBR is proposed to adjust the image. Third, based on the specific requirements of the reflected light image segmentation, the array cells are segmented into dots as large as possible and the distance between the dots is equal in the corrected image. Experimental results show that the pretreatment part of this method can effectively avoid the influence of complex background and complete the binarization processing of the image. The tilt correction algorithm has a shorter computation time, which makes it highly suitable for tilt correction of reflected light images. The segmentation algorithm makes the dots in a regular arrangement, excludes the edges and the bright spots. This method could be utilized in the fast, accurate and automatic dots extraction of the PSi microarray reflected light image. PMID:28594383

Saccade latency indexes exogenous and endogenous object-based attention.

PubMed

Şentürk, Gözde; Greenberg, Adam S; Liu, Taosheng

2016-10-01

Classic studies of object-based attention have utilized keypress responses as the main dependent measure. However, people typically make saccades to fixate important objects. Recent work has shown that attention may act differently when it is deployed covertly versus in advance of a saccade. We further investigated the link between saccades and attention by examining whether object-based effects can be observed for saccades. We adapted the classical double-rectangle cueing paradigm of Egly, Driver, and Rafal (1994), and measured both the first saccade latency and the keypress reaction time (RT) to a target that appeared at the end of one of the two rectangles. Our results showed that saccade latencies exhibited higher sensitivity than did RTs for detecting effects of attention. We also assessed the generality of the attention effects by testing three types of cues: hybrid (predictive and peripheral), exogenous (nonpredictive and peripheral), and endogenous (predictive and central). We found that both RTs and saccade latencies exhibited effects of both space-based and object-based attentional selection. However, saccade latencies showed a more robust attentional modulation than RTs. For the exogenous cues, we observed a spatial inhibition of return along with an object-based effect, implying that object-based attention is independent of space-based attention. Overall, our results revealed an oculomotor correlate of object-based attention, suggesting that, in addition to spatial priority, object-level priority also affects saccade planning.

Involvement of peripheral and spinal tumor necrosis factor α in spinal cord hyperexcitability during knee joint inflammation in rats.

PubMed

König, Christian; Zharsky, Maxim; Möller, Christian; Schaible, Hans-Georg; Ebersberger, Andrea

2014-03-01

Tumor necrosis factor α (TNFα) is produced not only in peripheral tissues, but also in the spinal cord. The purpose of this study was to address the potential of peripheral and spinal TNFα to induce and maintain spinal hyperexcitability, which is a hallmark of pain states in the joints during rheumatoid arthritis and osteoarthritis. In vivo recordings of the responses of spinal cord neurons to nociceptive knee input under normal conditions and in the presence of experimental knee joint inflammation were obtained in anesthetized rats. TNFα, etanercept, or antibodies to TNF receptors were applied to either the knee joint or the spinal cord surface. Injection of TNFα into the knee joint cavity increased the responses of spinal cord neurons to mechanical joint stimulation, and injection of etanercept into the knee joint reduced the inflammation-evoked spinal activity. These spinal effects closely mirrored the induction and reduction of peripheral sensitization. Responses to joint stimulation were also enhanced by spinal application of TNFα, and spinal application of either etanercept or anti-TNF receptor type I significantly attenuated the generation of inflammation-evoked spinal hyperexcitability, which is characterized by widespread pain sensitization beyond the inflamed joint. Spinally applied etanercept did not reduce established hyperexcitability in the acute kaolin/carrageenan model. In antigen-induced arthritis, etanercept decreased spinal responses on day 1, but not on day 3. While peripheral TNFα increases spinal responses to joint stimulation, spinal TNFα supports the generation of the full pattern of spinal hyperexcitability. However, established spinal hyperexcitability may be maintained by downstream mechanisms that are independent of spinal TNFα. Copyright © 2014 by the American College of Rheumatology.

Subdural Thoracolumbar Spine Hematoma after Spinal Anesthesia: A Rare Occurrence and Literature Review of Spinal Hematomas after Spinal Anesthesia.

PubMed

Maddali, Prasanthi; Walker, Blake; Fisahn, Christian; Page, Jeni; Diaz, Vicki; Zwillman, Michael E; Oskouian, Rod J; Tubbs, R Shane; Moisi, Marc

2017-02-16

Spinal hematomas are a rare but serious complication of spinal epidural anesthesia and are typically seen in the epidural space; however, they have been documented in the subdural space. Spinal subdural hematomas likely exist within a traumatically induced space within the dural border cell layer, rather than an anatomical subdural space. Spinal subdural hematomas present a dangerous clinical situation as they have the potential to cause significant compression of neural elements and can be easily mistaken for spinal epidural hematomas. Ultrasound can be an effective modality to diagnose subdural hematoma when no epidural blood is visualized. We have reviewed the literature and present a full literature review and a case presentation of an 82-year-old male who developed a thoracolumbar spinal subdural hematoma after spinal epidural anesthesia. Anticoagulant therapy is an important predisposing risk factor for spinal epidural hematomas and likely also predispose to spinal subdural hematomas. It is important to consider spinal subdural hematomas in addition to spinal epidural hematomas in patients who develop weakness after spinal epidural anesthesia, especially in patients who have received anticoagulation.

Control of an Ambulatory Exoskeleton with a Brain-Machine Interface for Spinal Cord Injury Gait Rehabilitation.

PubMed

López-Larraz, Eduardo; Trincado-Alonso, Fernando; Rajasekaran, Vijaykumar; Pérez-Nombela, Soraya; Del-Ama, Antonio J; Aranda, Joan; Minguez, Javier; Gil-Agudo, Angel; Montesano, Luis

2016-01-01

The closed-loop control of rehabilitative technologies by neural commands has shown a great potential to improve motor recovery in patients suffering from paralysis. Brain-machine interfaces (BMI) can be used as a natural control method for such technologies. BMI provides a continuous association between the brain activity and peripheral stimulation, with the potential to induce plastic changes in the nervous system. Paraplegic patients, and especially the ones with incomplete injuries, constitute a potential target population to be rehabilitated with brain-controlled robotic systems, as they may improve their gait function after the reinforcement of their spared intact neural pathways. This paper proposes a closed-loop BMI system to control an ambulatory exoskeleton-without any weight or balance support-for gait rehabilitation of incomplete spinal cord injury (SCI) patients. The integrated system was validated with three healthy subjects, and its viability in a clinical scenario was tested with four SCI patients. Using a cue-guided paradigm, the electroencephalographic signals of the subjects were used to decode their gait intention and to trigger the movements of the exoskeleton. We designed a protocol with a special emphasis on safety, as patients with poor balance were required to stand and walk. We continuously monitored their fatigue and exertion level, and conducted usability and user-satisfaction tests after the experiments. The results show that, for the three healthy subjects, 84.44 ± 14.56% of the trials were correctly decoded. Three out of four patients performed at least one successful BMI session, with an average performance of 77.6 1 ± 14.72%. The shared control strategy implemented (i.e., the exoskeleton could only move during specific periods of time) was effective in preventing unexpected movements during periods in which patients were asked to relax. On average, 55.22 ± 16.69% and 40.45 ± 16.98% of the trials (for healthy subjects and patients, respectively) would have suffered from unexpected activations (i.e., false positives) without the proposed control strategy. All the patients showed low exertion and fatigue levels during the performance of the experiments. This paper constitutes a proof-of-concept study to validate the feasibility of a BMI to control an ambulatory exoskeleton by patients with incomplete paraplegia (i.e., patients with good prognosis for gait rehabilitation).

Control of an Ambulatory Exoskeleton with a Brain–Machine Interface for Spinal Cord Injury Gait Rehabilitation

PubMed Central

López-Larraz, Eduardo; Trincado-Alonso, Fernando; Rajasekaran, Vijaykumar; Pérez-Nombela, Soraya; del-Ama, Antonio J.; Aranda, Joan; Minguez, Javier; Gil-Agudo, Angel; Montesano, Luis

2016-01-01

The closed-loop control of rehabilitative technologies by neural commands has shown a great potential to improve motor recovery in patients suffering from paralysis. Brain–machine interfaces (BMI) can be used as a natural control method for such technologies. BMI provides a continuous association between the brain activity and peripheral stimulation, with the potential to induce plastic changes in the nervous system. Paraplegic patients, and especially the ones with incomplete injuries, constitute a potential target population to be rehabilitated with brain-controlled robotic systems, as they may improve their gait function after the reinforcement of their spared intact neural pathways. This paper proposes a closed-loop BMI system to control an ambulatory exoskeleton—without any weight or balance support—for gait rehabilitation of incomplete spinal cord injury (SCI) patients. The integrated system was validated with three healthy subjects, and its viability in a clinical scenario was tested with four SCI patients. Using a cue-guided paradigm, the electroencephalographic signals of the subjects were used to decode their gait intention and to trigger the movements of the exoskeleton. We designed a protocol with a special emphasis on safety, as patients with poor balance were required to stand and walk. We continuously monitored their fatigue and exertion level, and conducted usability and user-satisfaction tests after the experiments. The results show that, for the three healthy subjects, 84.44 ± 14.56% of the trials were correctly decoded. Three out of four patients performed at least one successful BMI session, with an average performance of 77.6 1 ± 14.72%. The shared control strategy implemented (i.e., the exoskeleton could only move during specific periods of time) was effective in preventing unexpected movements during periods in which patients were asked to relax. On average, 55.22 ± 16.69% and 40.45 ± 16.98% of the trials (for healthy subjects and patients, respectively) would have suffered from unexpected activations (i.e., false positives) without the proposed control strategy. All the patients showed low exertion and fatigue levels during the performance of the experiments. This paper constitutes a proof-of-concept study to validate the feasibility of a BMI to control an ambulatory exoskeleton by patients with incomplete paraplegia (i.e., patients with good prognosis for gait rehabilitation). PMID:27536214

Dual spinal lesion paradigm in the cat: evolution of the kinematic locomotor pattern.

PubMed

Barrière, Grégory; Frigon, Alain; Leblond, Hugues; Provencher, Janyne; Rossignol, Serge

2010-08-01

The recovery of voluntary quadrupedal locomotion after an incomplete spinal cord injury can involve different levels of the CNS, including the spinal locomotor circuitry. The latter conclusion was reached using a dual spinal lesion paradigm in which a low thoracic partial spinal lesion is followed, several weeks later, by a complete spinal transection (i.e., spinalization). In this dual spinal lesion paradigm, cats can express hindlimb walking 1 day after spinalization, a process that normally takes several weeks, suggesting that the locomotor circuitry within the lumbosacral spinal cord had been modified after the partial lesion. Here we detail the evolution of the kinematic locomotor pattern throughout the dual spinal lesion paradigm in five cats to gain further insight into putative neurophysiological mechanisms involved in locomotor recovery after a partial spinal lesion. All cats recovered voluntary quadrupedal locomotion with treadmill training (3-5 days/wk) over several weeks. After the partial lesion, the locomotor pattern was characterized by several left/right asymmetries in various kinematic parameters, such as homolateral and homologous interlimb coupling, cycle duration, and swing/stance durations. When no further locomotor improvement was observed, cats were spinalized. After spinalization, the hindlimb locomotor pattern rapidly reappeared, but left/right asymmetries in swing/stance durations observed after the partial lesion could disappear or reverse. It is concluded that, after a partial spinal lesion, the hindlimb locomotor pattern was actively maintained by new dynamic interactions between spinal and supraspinal levels but also by intrinsic changes within the spinal cord.

Subdural Thoracolumbar Spine Hematoma after Spinal Anesthesia: A Rare Occurrence and Literature Review of Spinal Hematomas after Spinal Anesthesia

PubMed Central

Maddali, Prasanthi; Walker, Blake; Fisahn, Christian; Page, Jeni; Diaz, Vicki; Zwillman, Michael E; Oskouian, Rod J; Tubbs, R. Shane

2017-01-01

Spinal hematomas are a rare but serious complication of spinal epidural anesthesia and are typically seen in the epidural space; however, they have been documented in the subdural space. Spinal subdural hematomas likely exist within a traumatically induced space within the dural border cell layer, rather than an anatomical subdural space. Spinal subdural hematomas present a dangerous clinical situation as they have the potential to cause significant compression of neural elements and can be easily mistaken for spinal epidural hematomas. Ultrasound can be an effective modality to diagnose subdural hematoma when no epidural blood is visualized. We have reviewed the literature and present a full literature review and a case presentation of an 82-year-old male who developed a thoracolumbar spinal subdural hematoma after spinal epidural anesthesia. Anticoagulant therapy is an important predisposing risk factor for spinal epidural hematomas and likely also predispose to spinal subdural hematomas. It is important to consider spinal subdural hematomas in addition to spinal epidural hematomas in patients who develop weakness after spinal epidural anesthesia, especially in patients who have received anticoagulation. PMID:28357164

Maladaptive spinal plasticity opposes spinal learning and recovery in spinal cord injury

PubMed Central

Ferguson, Adam R.; Huie, J. Russell; Crown, Eric D.; Baumbauer, Kyle M.; Hook, Michelle A.; Garraway, Sandra M.; Lee, Kuan H.; Hoy, Kevin C.; Grau, James W.

2012-01-01

Synaptic plasticity within the spinal cord has great potential to facilitate recovery of function after spinal cord injury (SCI). Spinal plasticity can be induced in an activity-dependent manner even without input from the brain after complete SCI. A mechanistic basis for these effects is provided by research demonstrating that spinal synapses have many of the same plasticity mechanisms that are known to underlie learning and memory in the brain. In addition, the lumbar spinal cord can sustain several forms of learning and memory, including limb-position training. However, not all spinal plasticity promotes recovery of function. Central sensitization of nociceptive (pain) pathways in the spinal cord may emerge in response to various noxious inputs, demonstrating that plasticity within the spinal cord may contribute to maladaptive pain states. In this review we discuss interactions between adaptive and maladaptive forms of activity-dependent plasticity in the spinal cord below the level of SCI. The literature demonstrates that activity-dependent plasticity within the spinal cord must be carefully tuned to promote adaptive spinal training. Prior work from our group has shown that stimulation that is delivered in a limb position-dependent manner or on a fixed interval can induce adaptive plasticity that promotes future spinal cord learning and reduces nociceptive hyper-reactivity. On the other hand, stimulation that is delivered in an unsynchronized fashion, such as randomized electrical stimulation or peripheral skin injuries, can generate maladaptive spinal plasticity that undermines future spinal cord learning, reduces recovery of locomotor function, and promotes nociceptive hyper-reactivity after SCI. We review these basic phenomena, how these findings relate to the broader spinal plasticity literature, discuss the cellular and molecular mechanisms, and finally discuss implications of these and other findings for improved rehabilitative therapies after SCI. PMID:23087647

TRIPPy: Python-based Trailed Source Photometry

NASA Astrophysics Data System (ADS)

Fraser, Wesley C.; Alexandersen, Mike; Schwamb, Megan E.; Marsset, Michael E.; Pike, Rosemary E.; Kavelaars, JJ; Bannister, Michele T.; Benecchi, Susan; Delsanti, Audrey

2016-05-01

TRIPPy (TRailed Image Photometry in Python) uses a pill-shaped aperture, a rectangle described by three parameters (trail length, angle, and radius) to improve photometry of moving sources over that done with circular apertures. It can generate accurate model and trailed point-spread functions from stationary background sources in sidereally tracked images. Appropriate aperture correction provides accurate, unbiased flux measurement. TRIPPy requires numpy, scipy, matplotlib, Astropy (ascl:1304.002), and stsci.numdisplay; emcee (ascl:1303.002) and SExtractor (ascl:1010.064) are optional.

Hydrothermal Crystal Growth of Lithium Tetraborate and Lithium Gamma-Metaborate

DTIC Science & Technology

2014-03-27

could be atomic nuclei, the center of mass of some complex—those details are immaterial. Both the rectangle and lozenge form potential cross-sections...HR y d L Figure 10. The red lines are the various contours of solution of 9, using a = 10 Bohr radii and the mass of coefficients on the LHS forced to...absorptivity is significantly below that of the transition metals or the actinides [9]. The lithium borate crystals are therefore a strong candidate for

Impact of Resolution in Multi-Conjugate Adaptive Optics Systems Using Segmented Mirrors (Preprint)

DTIC Science & Technology

2009-06-01

and 100 percent fill factor. The DM1 influence function for each subaperture is modelled as a rectangle. As the apparent resolution of DM1 in the...modelled as a continuous facesheet. To account for the impact of adjoining actuators, an influence function is applied which essentially smoothes out...continuous DMs.20 Lukin’s influence function is closer to that of Jagourel and Gafford,21 or more simplified than the general higher order Gaussian function

Louisville, KY, USA

NASA Image and Video Library

1973-06-22

SL2-10-260 (22 June 1973) --- The meandering Ohio River bisecting this image is the border between Kentucky and Indiana. Louisville, KY (38.5N, 86.0W) on the south shore, is the main city seen in this predominately agricultural region where much of the native hardwood forests have been preserved in the hilly terrain. The main crops in this region include corn, alfalfa, wheat and soybeans. The dark rectangle in south Indiana near the river is The U.S. Army's Jefferson Proving Ground. Photo credit: NASA

High Throughput Screen to Identify Novel Drugs that Inhibit Prostate Cancer Metastasis

DTIC Science & Technology

2007-10-01

determined by electrophoresis on 8% denaturing polyacryl - amide gel containing 7 M urea. A 10-bp 32P-labeled ladder and sequencing reaction performed with...isolated from nuclear lysates from P69 and C4-2 cells. The bands shown as rectangles were excised after staining of the proteins in the gel and then...the same primer on a genomic clone was used as a reference. The gel was dried, and the radioactive signals were identified by phos- phorimaging (Storm

Metaphoric Car Drawings By a 12-Year-Old Congenitally Blind Girl.

PubMed

Chao, Hsin-Yi; Kennedy, John M

2015-12-01

A 12-year-old congenitally-blind girl drew a car moving, stationary, and braking. For stationary, she put the wheels inside the car and, for braking, drew the wheels as rough rectangles. At the age verbal metaphor is understood (Winner, 1988), the girl invented metaphoric drawings. In these, what is shown is not what is meant. In late childhood, metaphor may be understood similarly in pictures and words and by the sighted and blind. © The Author(s) 2015.

Modeling of Electrochemical Copying in a Finite-Width Cell

NASA Astrophysics Data System (ADS)

Zhitnikov, V. P.; Sherykhalina, N. M.; Zaripov, A. A.

2017-11-01

The problem of modeling of electrochemical machining is reduced to the solution of the Schwartz problem on a parametrical rectangle with the use of theta-functions. Various conditions (non-equipotentiality of electrodes and inconstancy of current efficiency) at the boundary of a processed surface are considered. Nonstationary, quasistationary, stationary, and limit solutions are studied. Results of machining of surfaces by tool electrodes of various shapes are given. It is shown that machining mode parameters significantly affect the dissolved layer size necessary for obtaining high-precision copying.

Fundamental Properties of the Red Square

NASA Astrophysics Data System (ADS)

Tuthill, Peter; Barnes, Peter; Cohen, Martin; Schmidt, Timothy

2007-04-01

This proposal follows the exciting recent discovery of the Red Square, the first near-sibling to the illustrious Red Rectangle; and also a potential example progenitor system for supernovae such as SN 1987A. Exploiting the unique extremely wide bandwidth correlator available at Mopra, we propose to rapidly and efficiently explore the molecular environment of this unique new object at 3 mm. This should reveal the fundamental properties of the gas in the underlying stellar system, and will provide the necessary springboard for future spatially-resolved work with interferometers.

An exact plane-stress solution for a class of problems in orthotropic elasticity

NASA Technical Reports Server (NTRS)

Erb, D. A.; Cooper, P. A.; Weisshaar, T. A.

1982-01-01

An exact solution for the stress field within a rectangular slab of orthotropic material is found using a two dimensional Fourier series formulation. The material is required to be in plane stress, with general stress boundary conditions, and the principle axes of the material must be parallel to the sides of the rectangle. Two load cases similar to those encountered in materials testing are investigated using the solution. The solution method has potential uses in stress analysis of composite structures.

Techniques for interpretation of geoid anomalies

NASA Technical Reports Server (NTRS)

Chapman, M. E.

1979-01-01

For purposes of geological interpretation, techniques are developed to compute directly the geoid anomaly over models of density within the earth. Ideal bodies such as line segments, vertical sheets, and rectangles are first used to calculate the geoid anomaly. Realistic bodies are modeled with formulas for two-dimensional polygons and three-dimensional polyhedra. By using Fourier transform methods the two-dimensional geoid is seen to be a filtered version of the gravity field, in which the long-wavelength components are magnified and the short-wavelength components diminished.

An Evaluation and Comparison of Several Measures of Image Quality for Television Displays

DTIC Science & Technology

1979-01-01

vehicles, buildings, or faces , or they may be artificial much as trn-bar patterns, rectangles, or sine waves. The typical objective image quality assessment...Snyder (1974b) wac able to obtain very good correlations with reaction time and correct responses for a face recognition task. Display quality was varied...recognition versus log JUDA for the target recognition study of Chapter 4, 5) graph of angle oubtended by target at recognitio , versus log JNDA for the

U.S. Southern Command Government Purchase Card Controls Need Improvement to Prevent Improper Purchases

DTIC Science & Technology

2014-12-19

track or maintain training records for ensuring A/BOs and cardholders received the initial and refresher trainings needed to properly use a GPC...required refresher training is completed. A/OPCs are also required to provide additional training on simplified acquisitions procedures to...Crystal Prestige, rectangle 8-3/4-inch 1 39.38 39.38 36 Crystal Service, Buffet 3186 1 40.00 40.00 37 Crystal Tray, Bread 2 25.00 50.00 38

Burkholderia Mallei tssM Encodes a Secreted Deubiquitinase that is Expressed Inside Infected RAW 264.7 Murine Macrophages

DTIC Science & Technology

2008-10-13

Furthermore, the encoded protein of this gene is only 30 kDa. A potential GTG start codon at position 625 also encodes a protein that is too small...horizontal bar and putative alternate translation initiation sites (ATG, GTG , and TTG) are indicated. The sizes and locations of the proteins encoded... gray line with rounded rectangles showing sequence features and motifs, including the Ala- and Pro-rich N-terminal region and the C-terminal Cys and

Utah FORGE Site Earthquake Animation

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

Joe Moore

This is a .kml earthquake animation covering the period of 1991 - 2011 for the Utah Milford FORGE site. It displays seismic events using different sized bubbles according to magnitude. It covers the general Utah FORGE area (large shaded rectangle) with the final site displayed as a smaller polygon along the northwestern margin. Earthquakes are subdivide into clusters and the time, date, and magnitude of each event is included. Nearby seismic stations are symbolized with triangles. This was created by the University of Utah Seismograph Stations (UUSS).

Analytic Simulation of the Performance of Mobile Maintenance Contact Teams

DTIC Science & Technology

1985-05-01

RECTANGULAR THE CUSTOMERS, REQUIRING MAINT SERVICE, ARE ASSUMED DISTRIBUTED WITHIN A RECTANGLE WITH DIMENSIONS ARANGE ’BY BRANGE . THE POPULATION OF...AND SERVE A CUSTOMER. ’INPUTS: ’FLAG.DIST ’FLAG.FIFO I PR I NT ARANGE ’ BRANGE SPEED 4 POP ’NSERVE MTBF MTTR AN INTEGER FLAG TO INDICATE...TEAMlS). 81 READ ARANGE 32 PRINT ’I LINE THUS INPUT THE DEPTH CCROSS-FRONTAL; DIMENSION (KM; OF THE AREA OF THE TEAMiS;. 84 READ BRANGE

A comparison of 25 gauge Quincke spinal needle with 26 gauge Eldor spinal needle for the elective Caesarian sections: insertion characteristics and complications.

PubMed

Tabedar, S; Maharjan, S K; Shrestha, B R; Shrestha, B M

2003-01-01

The study was designed to compare the insertion characteristics and incidence of PDPH between 25 gauge Quincke needle and 26 gauge Eldor needle for spinal anaesthesia in elective c/s. 60 pregnant women (aged 19-35 yrs and weighing 58 -67 kg) undergoing elective caesarean section were randomized into group A (Quincke spinal needle group) or group B (Eldor spinal needle group). Spinal anaesthesia was performed with 2.9 ml 0.5% heavy bupivacaine using 25 gauge Quincke spinal needle in group A and 26 Gauge Eldor spinal needle in group B. Onset, time of first identification of backflow of CSF, number of attempts, level of sensory and motor blockade, failure of anaesthesia, inadequate anaesthesia and incidence of PDPH were recorded. Quincke spinal needle was found easy at insertion, first attempt was successful in 90% of cases, whereas Eldor spinal needle was successful at first attempt in only 60% of cases. Early identification of CSF was seen in Eldor spinal needle group in 3.5 seconds vs. 5.2 seconds in Quincke spinal needle group. Blood mixed CSF was seen in 8 Quincke spinal needle group vs. none in Eldor spinal needle group. Onset was similar between both groups i.e. in 6 minutes. Failure of anaesthesia was none in Eldor spinal needle group vs. 2 in quincke spinal needle group. Height of sensory block achieved was T4 level in 26 parturients,T6 in 1 ,T8 in 1 and no anaesthesia at all in another 2 parturient as compared to T4 level in 29 and T3 in 1 parturient in Eldor spinal needle group. The degree of motor block with the use of Bromage criteria showed a motor score of 1 or 2 in 26 parturients in Quincke spinal needle group vs. same in all cases in Eldor spinal needle group. The total incidence of PDPH was 8.3 % (5 out of 60 parturient) which occurred all in Quincke spinal needle group. 2 parturient who developed severe PDPH required epidural blood patch. 26 gauge Eldor spinal needle was found to be better than 25 gauge Quincke spinal needle for caesarian sections to decrease the incidence of PDPH, though not all insertion characteristics were in favour of the Eldor needle.

N-methyl-D-aspartate receptor antagonist MK-801 prevents apoptosis in rats that have undergone fetal spinal cord transplantation following spinal hemisection.

PubMed

Zhang, Qiang; Shao, Yang; Zhao, Changsong; Cai, Juan; Sun, Sheng

2014-12-01

Spinal cord injury is the main cause of paraplegia, but effective therapies for it are lacking. Embryonic spinal cord transplantation is able to repair spinal cord injury, albeit with a large amount of neuronal apoptosis remaining in the spinal cord. MK-801, an N-methyl-D-aspartate (NMDA) receptor antagonist, is able to reduce cell death by decreasing the concentration of excitatory amino acids and preventing extracellular calcium ion influx. In this study, the effect of MK-801 on the apoptosis of spinal cord neurons in rats that have received a fetal spinal cord (FSC) transplant following spinal hemisection was investigated. Wistar rats were divided into three groups: Spinal cord hemisection injury with a combination of FSC transplantation and MK-801 treatment (group A); spinal cord hemisection injury with FSC transplantation (group B); and spinal cord injury with insertion of a Gelfoam pledget (group C). The rats were sacrificed 1, 3, 7 and 14 days after the surgery. Apoptosis in spinal slices from the injured spinal cord was examined by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling reaction, and the expression of B-cell lymphoma-2 (Bcl-2) was measured by immunohistochemistry. The positive cells were quantitatively analyzed using a computer image analysis system. The rate of apoptosis and the positive expression of Bcl-2 protein in the spinal cord neurons in the three groups decreased in the following order: C>B>A (P<0.05) and A>B>C (P<0.05), respectively. This indicates that treatment with the NMDA receptor antagonist MK-801 prevents apoptosis in the spinal cord neurons of rats that have undergone FSC transplantation following spinal hemisection.

N-methyl-D-aspartate receptor antagonist MK-801 prevents apoptosis in rats that have undergone fetal spinal cord transplantation following spinal hemisection

PubMed Central

ZHANG, QIANG; SHAO, YANG; ZHAO, CHANGSONG; CAI, JUAN; SUN, SHENG

2014-01-01

Spinal cord injury is the main cause of paraplegia, but effective therapies for it are lacking. Embryonic spinal cord transplantation is able to repair spinal cord injury, albeit with a large amount of neuronal apoptosis remaining in the spinal cord. MK-801, an N-methyl-D-aspartate (NMDA) receptor antagonist, is able to reduce cell death by decreasing the concentration of excitatory amino acids and preventing extracellular calcium ion influx. In this study, the effect of MK-801 on the apoptosis of spinal cord neurons in rats that have received a fetal spinal cord (FSC) transplant following spinal hemisection was investigated. Wistar rats were divided into three groups: Spinal cord hemisection injury with a combination of FSC transplantation and MK-801 treatment (group A); spinal cord hemisection injury with FSC transplantation (group B); and spinal cord injury with insertion of a Gelfoam pledget (group C). The rats were sacrificed 1, 3, 7 and 14 days after the surgery. Apoptosis in spinal slices from the injured spinal cord was examined by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling reaction, and the expression of B-cell lymphoma-2 (Bcl-2) was measured by immunohistochemistry. The positive cells were quantitatively analyzed using a computer image analysis system. The rate of apoptosis and the positive expression of Bcl-2 protein in the spinal cord neurons in the three groups decreased in the following order: C>B>A (P<0.05) and A>B>C (P<0.05), respectively. This indicates that treatment with the NMDA receptor antagonist MK-801 prevents apoptosis in the spinal cord neurons of rats that have undergone FSC transplantation following spinal hemisection. PMID:25371724

Spinal arteriovenous shunts: accuracy of shunt detection, localization, and subtype discrimination using spinal magnetic resonance angiography and manual contrast injection using a syringe.

PubMed

Unsrisong, Kittisak; Taphey, Siriporn; Oranratanachai, Kanokporn

2016-04-01

The object of this study was to evaluate the accuracy of fast 3D contrast-enhanced spinal MR angiography (MRA) using a manual syringe contrast injection technique for detecting and evaluating spinal arteriovenous shunts (AVSs). This was a retrospective study of 15 patients and 20 spinal MRA and catheter angiography studies. The accuracy of using spinal MRA to detect spinal AVS, localize shunts, and discriminate the subtype and dominant arterial feeder of the AVS were studied. There were 14 pretherapeutic and 6 posttherapeutic follow-up spinal MRA and catheter spinal angiography studies. The spinal AVS was demonstrated in 17 of 20 studies. Spinal MRA demonstrated 100% sensitivity for detecting spinal AVS with no false-negative results. A 97% accuracy rate for AVS subtype discrimination and shunt level localization was achieved using this study's diagnostic criteria. The detection of the dominant arterial feeder was limited to 9 of these 17 cases (53%). The fast 3D contrast-enhanced MRA technique performed using manual syringe contrast injection can detect the presence of a spinal AVS, locate the shunt level, and discriminate AVS subtype in most cases, but is limited when detecting small arterial feeders.

Tethered Spinal Cord Syndrome

MedlinePlus

... the spinal cord. These attachments cause an abnormal stretching of the spinal cord. The course of the ... the spinal cord. These attachments cause an abnormal stretching of the spinal cord. The course of the ...

A microcontroller platform for the rapid prototyping of functional electrical stimulation-based gait neuroprostheses.

PubMed

Luzio de Melo, Paulo; da Silva, Miguel Tavares; Martins, Jorge; Newman, Dava

2015-05-01

Functional electrical stimulation (FES) has been used over the last decades as a method to rehabilitate lost motor functions of individuals with spinal cord injury, multiple sclerosis, and post-stroke hemiparesis. Within this field, researchers in need of developing FES-based control solutions for specific disabilities often have to choose between either the acquisition and integration of high-performance industry-level systems, which are rather expensive and hardly portable, or develop custom-made portable solutions, which despite their lower cost, usually require expert-level electronic skills. Here, a flexible low-cost microcontroller-based platform for rapid prototyping of FES neuroprostheses is presented, designed for reduced execution complexity, development time, and production cost. For this reason, the Arduino open-source microcontroller platform was used, together with off-the-shelf components whenever possible. The developed system enables the rapid deployment of portable FES-based gait neuroprostheses, being flexible enough to allow simple open-loop strategies but also more complex closed-loop solutions. The system is based on a modular architecture that allows the development of optimized solutions depending on the desired FES applications, even though the design and testing of the platform were focused toward drop foot correction. The flexibility of the system was demonstrated using two algorithms targeting drop foot condition within different experimental setups. Successful bench testing of the device in healthy subjects demonstrated these neuroprosthesis platform capabilities to correct drop foot. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Disruption of δ-opioid receptor phosphorylation at threonine 161 attenuates morphine tolerance in rats with CFA-induced inflammatory hypersensitivity.

PubMed

Chen, Hai-Jing; Xie, Wei-Yan; Hu, Fang; Zhang, Ying; Wang, Jun; Wang, Yun

2012-04-01

Our previous study identified Threonine 161 (Thr-161), located in the second intracellular loop of the δ-opioid receptor (DOR), as the only consensus phosphorylation site for cyclin-dependent kinase 5 (Cdk5). The aim of this study was to assess the function of DOR phosphorylation by Cdk5 in complete Freund's adjuvant (CFA)-induced inflammatory pain and morphine tolerance. Dorsal root ganglion (DRG) neurons of rats with CFA-induced inflammatory pain were acutely dissociated and the biotinylation method was used to explore the membrane localization of phosphorylated DOR at Thr-161 (pThr-161-DOR), and paw withdrawal latency was measured after intrathecal delivery of drugs or Tat-peptide, using a radiant heat stimulator in rats with CFA-induced inflammatory pain. Both the total amount and the surface localization of pThr-161-DOR were significantly enhanced in the ipsilateral DRG following CFA injection. Intrathecal delivery of the engineered Tat fusion-interefering peptide corresponding to the second intracellular loop of DOR (Tat-DOR-2L) increased inflammatory hypersensitivity, and inhibited DOR- but not µ-opioid receptor-mediated spinal analgesia in CFA-treated rats. However, intrathecal delivery of Tat-DOR-2L postponed morphine antinociceptive tolerance in rats with CFA-induced inflammatory pain. Phosphorylation of DOR at Thr-161 by Cdk5 attenuates hypersensitivity and potentiates morphine tolerance in rats with CFA-induced inflammatory pain, while disruption of the phosphorylation of DOR at Thr-161 attenuates morphine tolerance.

Comparison of control and quality of bone cutting by using optical topographical imaging guided mechanical drill and 1070 nm laser with in-line coherent imaging

NASA Astrophysics Data System (ADS)

Razani, Marjan; Soudagar, Yasaman; Yu, Karen; Galbraith, Christopher M.; Webster, Paul J. L.; Van Vlack, Cole; Sun, Cuiru; Mariampillai, Adrian; Leung, Michael K. K.; Standish, Beau; Kiehl, Tim-Rasmus; Fraser, James M.; Yang, Victor X. D.

2013-03-01

Precision depth control of bone resection is necessary for safe surgical procedures in the spine. In this paper, we compare the control and quality of cutting bovine tail bone, as an ex vivo model of laminectomy and bony resection simulating spinal surgery, planned with micro-CT data and executed using two approaches: (a) mechanical milling guided by optical topographical imaging (OTI) and (b) optical milling using closed-loop inline coherent imaging (ICI) to monitor and control the incision depth of a high-power 1070 nm fiber laser in situ. OTI provides the in situ topology of the 2-dimensional surface of the bone orientation in the mechanical mill which is registered with the treatment plan derived from the micro-CT data. The coregistration allows the plan to be programmed into the mill which is then used as a benchmark of current surgical techniques. For laser cutting, 3D optical land marking with coaxial camera vision and the ICI system is used to coregister the treatment plan. The unstable, carbonization-mediated ablation behaviour of 1070 nm light and the unknown initial geometry of bone leads to unpredictable ablation which substantially limits the depth accuracy of open-loop cutting. However, even with such a non-ideal cutting laser, we demonstrate that ICI provides in situ high-speed feedback that automatically and accurately limits the laser's cut depth to effectively create an all-optical analogue to the mechanical mill.

Effect of locomotor training in completely spinalized cats previously submitted to a spinal hemisection.

PubMed

Martinez, Marina; Delivet-Mongrain, Hugo; Leblond, Hugues; Rossignol, Serge

2012-08-08

After a spinal hemisection in cats, locomotor plasticity occurring at the spinal level can be revealed by performing, several weeks later, a complete spinalization below the first hemisection. Using this paradigm, we recently demonstrated that the hemisection induces durable changes in the symmetry of locomotor kinematics that persist after spinalization. Can this asymmetry be changed again in the spinal state by interventions such as treadmill locomotor training started within a few days after the spinalization? We performed, in 9 adult cats, a spinal hemisection at thoracic level 10 and then a complete spinalization at T13, 3 weeks later. Cats were not treadmill trained during the hemispinal period. After spinalization, 5 of 9 cats were not trained and served as control while 4 of 9 cats were trained on the treadmill for 20 min, 5 d a week for 3 weeks. Using detailed kinematic analyses, we showed that, without training, the asymmetrical state of locomotion induced by the hemisection was retained durably after the subsequent spinalization. By contrast, training cats after spinalization induced a reversal of the left/right asymmetries, suggesting that new plastic changes occurred within the spinal cord through locomotor training. Moreover, training was shown to improve the kinematic parameters and the performance of the hindlimb on the previously hemisected side. These results indicate that spinal locomotor circuits, previously modified by past experience such as required for adaptation to the hemisection, can remarkably respond to subsequent locomotor training and improve bilateral locomotor kinematics, clearly showing the benefits of locomotor training in the spinal state.

Thiazides and Osteoporotic Spinal Fractures: A Suspected Linkage Investigated by Means of a Two-Center, Case-Control Study.

PubMed

De Vecchis, Renato; Ariano, Carmelina; Di Biase, Giuseppina; Noutsias, Michel

2017-11-01

An alleged association of chronic use of thiazide diuretics with an increased risk of bone fragility fractures has been highlighted by a relatively recent prospective cohort study. However, the concept that thiazides exert a beneficial effect on osteoporosis is still a predominant view. This effect would be mediated by the decrease in renal clearance of calcium ions, a pharmacological feature recognized for a long time now to this class of drugs, as opposed to the increase in calcium urinary excretion attributed instead to loop diuretics, i.e. furosemide and similar drugs. The purpose of this retrospective study was to attempt to clarify whether regular use of thiazide diuretics as antihypertensive therapeutics is associated with a significantly increased risk of osteoporotic fractures in female patients aged 65 or over. In this two-center retrospective study, we followed up a cohort of female patients with (n = 80) and without (n = 158) thiazide-induced hyponatremia. A total of 48 osteoporotic fractures were recorded during a median follow-up period of 57.5 months. By means of univariate regression analysis, an association was found between thiazide-induced hyponatremia and increased risk of vertebral fractures (odds ratio (OR): 7.6; 95% confidence interval (CI): 3.755 - 15.39; P < 0.0001). Multivariate regression analysis, however, showed that age (OR: 1.823; 95% CI: 1.211 - 2.743) and body mass index (OR: 0.156; 95% CI: 0.038 - 0.645) were the only independent predictors of osteoporotic fractures. No association of a history of thiazide-induced hyponatremia and risk of fracture was noticeable in the final model. Because thiazide-induced hyponatremia was associated with spinal fractures in univariate but not multivariate analysis, a possible explanation is that hyponatremia may be a confounder of the relation between body mass and spinal fractures. Indeed, reduced body mass especially among elderly women with small body build may confer heightened risk of thiazide-induced hyponatremia because of decreased bone sodium available for exchange with the serum sodium. Thus, occurrence of hyponatremia could only serve as an indirect surrogate marker for osteoporosis risk.

Increased long-latency reflex activity as a sufficient explanation for childhood hypertonic dystonia: a neuromorphic emulation study

NASA Astrophysics Data System (ADS)

Sohn, Won J.; Niu, Chuanxin M.; Sanger, Terence D.

2015-06-01

Objective. Childhood dystonia is a movement disorder that interferes with daily movements and can have a devastating effect on quality of life for children and their families. Although injury to basal ganglia is associated with dystonia, the neurophysiological mechanisms leading to the clinical manifestations of dystonia are not understood. Previous work suggested that long-latency stretch reflex (LLSR) is hyperactive in children with hypertonia due to secondary dystonia. We hypothesize that abnormal activity in motor cortices may cause an increase in the LLSR leading to hypertonia. Approach. We modeled two possibilities of hyperactive LLSR by either creating a tonic involuntary drive to cortex, or increasing the synaptic gain in cortical neurons. Both models are emulated using programmable very-large-scale-integrated-circuit hardware to test their sufficiency for producing dystonic symptoms. The emulation includes a joint with two Hill-type muscles, realistic muscle spindles, and 2,304 Izhikevich-type spiking neurons. The muscles are regulated by a monosynaptic spinal pathway with 32 ms delay and a long-latency pathway with 64 ms loop-delay representing transcortical/supra-spinal connections. Main results. When the limb is passively stretched, both models produce involuntary resistance with increased antagonist EMG responses similar to human data; also the muscle relaxation is delayed similar to human data. Both models predict reduced range of motion in voluntary movements. Significance. Although our model is a highly simplified and limited representation of reflex pathways, it shows that increased activity of the LLSR is by itself sufficient to cause many of the features of hypertonic dystonia.

Percutaneous Radiofrequency Ablation of Painful Spinal Tumors Adjacent to the Spinal Cord with Real-Time Monitoring of Spinal Canal Temperature: A Prospective Study

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

Nakatsuka, Atsuhiro, E-mail: nakatuka@clin.medic.mie-u.ac.jp; Yamakado, Koichiro; Takaki, Haruyuki

2009-01-15

PurposeTo prospectively evaluate the feasibility, safety, and clinical utility of bone radiofrequency (RF) ablation with real-time monitoring of the spinal canal temperature for the treatment of spinal tumors adjacent to the spinal cord.Materials and MethodsOur Institutional Review Board approved this study. Patients gave informed consent. The inclusion criteria were (a) a painful spinal metastasis and (b) a distance of 1 cm or less between the metastasis and the spinal cord. The thermocouple was placed in the spinal canal under CT fluoroscopic guidance. When the spinal canal temperature reached 45{sup o}C, RF application was immediately stopped. RF ablation was considered technicallymore » successful when the procedure was performed without major complications. Clinical success was defined as a fall in the visual analogue scale score of at least 2 points.ResultsTen patients with spinal tumors measuring 3-8 cm (mean, 4.9 {+-} 1.5 cm) were enrolled. The distance between the tumor and the spinal cord was 1-6 mm (mean, 2.4 {+-} 1.6 mm). All procedures were judged technically successful (100%). The spinal canal temperature did not exceed 45{sup o}C in 9 of the 10 patients (90%). In the remaining patient, the temperature rose to 48{sup o}C, resulting in transient neural damage, although RF application was immediately stopped when the temperature reached 45{sup o}C. Clinical success was achieved within 1 week in all patients (100%).ConclusionBone RF ablation with real-time monitoring of the spinal canal temperature is feasible, safe, and clinically useful for the treatment of painful spinal metastases adjacent to the spinal cord.« less

The Effects of Ketorolac Injected via Patient Controlled Analgesia Postoperatively on Spinal Fusion

PubMed Central

Park, Si-Young; Moon, Seong-Hwan; Park, Moon-Soo; Oh, Kyung-Soo

2005-01-01

Lumbar spinal fusions have been performed for spinal stability, pain relief and improved function in spinal stenosis, scoliosis, spinal fractures, infectious conditions and other lumbar spinal problems. The success of lumbar spinal fusion depends on multifactors, such as types of bone graft materials, levels and numbers of fusion, spinal instrumentation, electrical stimulation, smoking and some drugs such as nonsteroidal anti-inflammatory drugs (NSAIDs). From January 2000 to December 2001, 88 consecutive patients, who were diagnosed with spinal stenosis or spondylolisthesis, were retrospectively enrolled in this study. One surgeon performed all 88 posterolateral spinal fusions with instrumentation and autoiliac bone graft. The patients were divided into two groups. The first group (n=30) was infused with ketorolac and fentanyl intravenously via patient controlled analgesia (PCA) postoperatively and the second group (n=58) was infused only with fentanyl. The spinal fusion rates and clinical outcomes of the two groups were compared. The incidence of incomplete union or nonunion was much higher in the ketorolac group, and the relative risk was approximately 6 times higher than control group (odds ratio: 5.64). The clinical outcomes, which were checked at least 1 year after surgery, showed strong correlations with the spinal fusion status. The control group (93.1%) showed significantly better clinical results than the ketorolac group (77.6%). Smoking had no effect on the spinal fusion outcome in this study. Even though the use of ketorolac after spinal fusion can reduce the need for morphine, thereby decreasing morphine related complications, ketorolac used via PCA at the immediate postoperative state inhibits spinal fusion resulting in a poorer clinical outcome. Therefore, NSAIDs such as ketorolac, should be avoided after posterolateral spinal fusion. PMID:15861498

Biomechanical implications of lumbar spinal ligament transection.

PubMed

Von Forell, Gregory A; Bowden, Anton E

2014-11-01

Many lumbar spine surgeries either intentionally or inadvertently damage or transect spinal ligaments. The purpose of this work was to quantify the previously unknown biomechanical consequences of isolated spinal ligament transection on the remaining spinal ligaments (stress transfer), vertebrae (bone remodelling stimulus) and intervertebral discs (disc pressure) of the lumbar spine. A finite element model of the full lumbar spine was developed and validated against experimental data and tested in the primary modes of spinal motion in the intact condition. Once a ligament was removed, stress increased in the remaining spinal ligaments and changes occurred in vertebral strain energy, but disc pressure remained similar. All major biomechanical changes occurred at the same spinal level as the transected ligament, with minor changes at adjacent levels. This work demonstrates that iatrogenic damage to spinal ligaments disturbs the load sharing within the spinal ligament network and may induce significant clinically relevant changes in the spinal motion segment.

Comparison of segmental spinal movement control in adolescents with and without idiopathic scoliosis using modified pressure biofeedback unit.

PubMed

Luo, Hong-Ji; Lin, Shi-Xiang; Wu, Shyi-Kuen; Tsai, Mei-Wun; Lee, Shwn-Jen

2017-01-01

Postural rehabilitation emphasizing on motor control training of segmental spinal movements has been proposed to effectively reduce the scoliotic spinal deformities in adolescent idiopathic scoliosis (AIS). However, information regarding the impairments of segmental spinal movement control involving segmental spinal stabilizers in adolescent idiopathic scoliosis remains limited. Examination of segmental spinal movement control may provide a window for investigating the features of impaired movement control specific to spinal segments that may assist in the development of physiotherapeutic management of AIS. To compare segmental spinal movement control in adolescents with and without idiopathic scoliosis using modified pressure biofeedback unit. Segmental spinal movement control was assessed in twenty adolescents with idiopathic scoliosis (AISG) and twenty healthy adolescents (CG) using a modified pressure biofeedback unit. Participants performed segmental spinal movements that primarily involved segmental spinal stabilizing muscles with graded and sustained muscle contraction against/off a pressure cuff from baseline to target pressures and then maintained for 1 min. Pressure data during the 1-minute maintenance phase were collected for further analysis. Pressure deviation were calculated and compared between groups. The AISG had significantly greater pressure deviations for all segmental spinal movements of cervical, thoracic, and lumbar spine than the CG. Pressure biofeedback unit was feasible for assessing segmental spinal movement control in AIS. AISG exhibited poorer ability to grade and sustain muscle activities for local movements of cervical, thoracic, and lumbar spine, suggesting motor control training of segmental spinal movements involving segmental spinal stabilizing muscles on frontal, sagittal, and transverse planes were required.

Programmed self-assembly of DNA/RNA for biomedical applications

NASA Astrophysics Data System (ADS)

Wang, Pengfei

Three self-assembly strategies were utilized for assembly of novel functional DNA/RNA nanostructures. RNA-DNA hybrid origami method was developed to fabricate nano-objects (ribbon, rectangle, and triangle) with precisely controlled geometry. Unlike conventional DNA origami which use long DNA single strand as scaffold, a long RNA single strand was used instead, which was folded by short DNA single strands (staples) into prescribed objects through sequence specific hybridization between RNA and DNA. Single stranded tiles (SST) and RNA-DNA hybrid origami were utilized to fabricate a variety of barcode-like nanostructures with unique patterns by expanding a plain rectangle via introducing spacers (10-bp dsDNA segment) between parallel duplexes. Finally, complex 2D array and 3D polyhedrons with multiple patterns within one structure were assembled from simple DNA motifs. Two demonstrations of biomedical applications of DNA nanotechnology were presented. Firstly, lambda-DNA was used as template to direct the fabrication of multi-component magnetic nanoparticle chains. Nuclear magnetic relaxation (NMR) characterization showed superb magnetic relaxativity of the nanoparticle chains which have large potential to be utilized as MRI contrast agents. Secondly, DNA nanotechnology was introduced into the conformational study of a routinely used catalytic DNAzyme, the RNA-cleaving 10-23 DNAzyme. The relative angle between two flanking duplexes of the catalytic core was determined (94.8°), which shall be able to provide a clue to further understanding of the cleaving mechanism of this DNAzyme from a conformational perspective.

Polarized and asymmetric emission of single colloidal nanoplatelets (Conference Presentation)

NASA Astrophysics Data System (ADS)

Feng, Fu; N'Guyen, Thu Loan; Nasilowski, Michel; Lethiec, Clotilde M.; Dubertret, Benoit; Coolen, Laurent; Maître, Agnès.

2017-02-01

Efficient coupling of nanoemitters to photonic or plasmonic structures requires the control of the orientation of the emitting dipoles. Nevertheless controlling the dipole orientation remains an experimental challenge. Many experiments rely on the realization of numerous samples, in order to be able to statistically get a well aligned dipole to realize an efficient coupling to a nanostructure. In order to avoid these statistical trials, the knowledge of the nature of the emitter and its orientation is crucial for a deterministical approach. We developed a method [1],[2] relying on the combination of polarimetric measurement and emission diagram which gives fine information both on the emitting dipolar transition involved and on the dipolar orientation We analyse by this method square and rectangle single colloidal CdSe/CdS nanoplatetelets. We demonstrate that their emission can be described by just by two orthogonal dipoles lying in the plane of the platelets. More surprisingly the emission of the square nanoplatelets is not polarised whereas the rectangle one is. We demonstrate that this polarized emission is due to the rectangular shape anisotropy by a dielectric effect. [1] C. Lethiec, et al, Three-dimensional orientation measurement of a single fluorescent nanoemitter by polarization analysis, Phys. Rev. X 4, 021037 (2014), [2] C. Lethiec et al, Polarimetry-based analysis of dipolar transitions of single colloidal CdSe/CdS dot-inrods, New Journal of Physics 16, 093014 (2014) [3] S. Ithurria et al, colloidal nanoplatelets with 2 dimensional electronic structure, Nature Materials 10, 936 (2011)

Infrared thermography of the udder surface of dairy cattle: characteristics, methods, and correlation with rectal temperature.

PubMed

Metzner, Moritz; Sauter-Louis, Carola; Seemueller, Andrea; Petzl, Wolfram; Klee, Wolfgang

2014-01-01

Thermograms of the caudal udder surface were taken of five healthy cows before and after inoculation of Escherichia coli into the right hind quarter. Images in clinically normal udder quarters from cows without fever (CN) were compared with those post inoculation when cows had fever (⩾ 39.5°C) and showed elevation of somatic cell counts (⩾ 400,000 cells/mL) in the inoculated quarter (CM). Using graphic software tools, different geometric analysis tools (GATs: polygons, rectangles, lines) were set within the thermographic images. The following descriptive parameters (DPs) were employed: minimum value ('min'), maximum value ('max'), range ('max-min'), and arithmetic mean ('am'). Surface temperatures in group CN were between 34.1°C ('polygons'/'min') and 37.9°C ('polygons'/'max'), and in group CM between 34.5°C ('polygons'/'min') and 40.0°C ('polygons'/'max'). The greatest differences in the temperatures between CN and CM (2.06°C) were found in 'polygons' and 'rectangles' using 'max'. The smallest coefficient of variation in triplicate determinations was found in GAT 'polygons' with DP 'max' (Tmax) (0.15%), and the relationship to the rectal body temperature (Tr) could be described by Tr=5.68+0.874*Tmax. The results show that significant changes can be displayed best using the GAT 'polygons' and the DP 'max'. These methods should be considered for automated monitoring of udder health in dairy cows. Copyright © 2013 Elsevier Ltd. All rights reserved.

Amodal representation of occluded surfaces: role of invisible stimuli in apparent motion correspondence.

PubMed

Shimojo, S; Nakayama, K

1990-01-01

A series of demonstrations were created where the perceived depth of targets was controlled by stereoscopic disparity. A closer object (a cloud) was made to jump back and forth horizontally, partially occluding a farther object (a full moon). The more distant moon appeared stationary even though the unoccluded portion of it, a crescent, changed position. Reversal of the relative depth of the moon and cloud gave a totally different percept: the crescent appeared to flip back and forth in the front depth plane. Thus, the otherwise-robust apparent motion of the moon crescents was completely abolished in the cloud-closer case alone. This motion-blocking effect is attributed to the 'amodal presence' of the occluded surface continuing behind the occluding surface. To measure the effect of this occluded 'invisible' surface quantitatively, a bistable apparent motion display was used (Ramachandran and Anstis 1983a): two small rectangular-shaped targets changed their positions back and forth between two frames, and the disparity of a large centrally positioned rectangle was varied. When the perceived depths supported the possibility of amodal completion behind the large rectangle, increased vertical motion of the targets was found, suggesting that the amodal presence of the targets behind the occluder had effectively changed the center position of the moving targets for purposes of motion correspondence. Amodal contours are literally 'invisible', yet it is hypothesized that they have a neural representation at sufficiently early stages of visual processing to alter the correspondence solving process for apparent motion.

Periodic Orbits Contribution to the 2-Point Correlation Form Factor for Pseudo-Integrable Systems

NASA Astrophysics Data System (ADS)

Bogomolny, E.; Giraud, O.; Schmit, C.

Using heuristic arguments based on the trace formulas we relate the 2-point correlation form factor, K2(τ), at small values of τ with sums over classical periodic orbits for typical examples of pseudo-integrable systems. The later sums have been explicitly calculated for the following models: (i) plane billiards in the form of right triangles with one angle π/n and (ii) rectangular billiards with the Aharonov-Bohm flux line. In the first model, using the properties of the Veech structure, it is shown that K2(0)=(n+ɛ(n))/(3(n-2)), where ɛ(n)= 0 for odd n, ɛ(n)= 2 for even n not divisible by 3, and ɛ(n)=6 for even n divisible by 3. For completeness we also recall informally the main features of the Veech construction. In the second model the answer depends on arithmetical properties of ratios of flux line coordinates to the corresponding sides of the rectangle. When these ratios are non-commensurable irrational numbers, K2(0)=1-3 , where is the fractional part of the flux through the rectangle when and it is symmetric with respect to the line when . The comparison of these results with numerical calculations of the form factor is discussed in detail. The above values of K2(0) differ from all known examples of spectral statistics, thus confirming analytically the peculiarities of statistical properties of the energy levels in pseudo-integrable systems.

Features in visual search combine linearly

PubMed Central

Pramod, R. T.; Arun, S. P.

2014-01-01

Single features such as line orientation and length are known to guide visual search, but relatively little is known about how multiple features combine in search. To address this question, we investigated how search for targets differing in multiple features (intensity, length, orientation) from the distracters is related to searches for targets differing in each of the individual features. We tested race models (based on reaction times) and co-activation models (based on reciprocal of reaction times) for their ability to predict multiple feature searches. Multiple feature searches were best accounted for by a co-activation model in which feature information combined linearly (r = 0.95). This result agrees with the classic finding that these features are separable i.e., subjective dissimilarity ratings sum linearly. We then replicated the classical finding that the length and width of a rectangle are integral features—in other words, they combine nonlinearly in visual search. However, to our surprise, upon including aspect ratio as an additional feature, length and width combined linearly and this model outperformed all other models. Thus, length and width of a rectangle became separable when considered together with aspect ratio. This finding predicts that searches involving shapes with identical aspect ratio should be more difficult than searches where shapes differ in aspect ratio. We confirmed this prediction on a variety of shapes. We conclude that features in visual search co-activate linearly and demonstrate for the first time that aspect ratio is a novel feature that guides visual search. PMID:24715328

Normative data for three tests of visuocognitive function in primary school children: cross-sectional study.

PubMed

Williams, Cathy; Gilchrist, Iain D; Fraser, Sue; McCarthy, H M; Parker, Julie; Warnes, Penny; Young, Jill; Hyvarinen, Lea

2015-06-01

There is an increasing recognition that visuocognitive difficulties occur in children with neurodevelopmental problems. We obtained normative data for the performance of primary school children using three tests of visuocognitive function that are practicable in a clinical setting. We tested 214 children aged between 4 and 11 years without known developmental problems, using tests to assess (1) orientation recognition and adaptive movement (postbox task), (2) object recognition (rectangles task) and (3) spatial integration (contours task). 96% could do the postbox task with ease-only 4% (all aged <9 years) exhibited minor difficulties. Errors in the rectangles task decreased with age: 33% of children aged 4-5 years had major difficulties but >99% of children aged ≥6 years had no, or minor, difficulties. Median scores for the contours task improved with age, and after age 8 years, 99% could see the contour using long-range spatial integration rather than density. These different aspects of children's visuocognitive performance were testable in a field setting. The data provide a benchmark by which to judge performance of children with neurodevelopmental problems and may be useful in assessment with a view to providing effective supportive strategies for children whose visuocognitive skills are lower than the expectation for their age. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Optimization method of superpixel analysis for multi-contrast Jones matrix tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Miyazawa, Arata; Hong, Young-Joo; Makita, Shuichi; Kasaragod, Deepa K.; Miura, Masahiro; Yasuno, Yoshiaki

2017-02-01

Local statistics are widely utilized for quantification and image processing of OCT. For example, local mean is used to reduce speckle, local variation of polarization state (degree-of-polarization-uniformity (DOPU)) is used to visualize melanin. Conventionally, these statistics are calculated in a rectangle kernel whose size is uniform over the image. However, the fixed size and shape of the kernel result in a tradeoff between image sharpness and statistical accuracy. Superpixel is a cluster of pixels which is generated by grouping image pixels based on the spatial proximity and similarity of signal values. Superpixels have variant size and flexible shapes which preserve the tissue structure. Here we demonstrate a new superpixel method which is tailored for multifunctional Jones matrix OCT (JM-OCT). This new method forms the superpixels by clustering image pixels in a 6-dimensional (6-D) feature space (spatial two dimensions and four dimensions of optical features). All image pixels were clustered based on their spatial proximity and optical feature similarity. The optical features are scattering, OCT-A, birefringence and DOPU. The method is applied to retinal OCT. Generated superpixels preserve the tissue structures such as retinal layers, sclera, vessels, and retinal pigment epithelium. Hence, superpixel can be utilized as a local statistics kernel which would be more suitable than a uniform rectangle kernel. Superpixelized image also can be used for further image processing and analysis. Since it reduces the number of pixels to be analyzed, it reduce the computational cost of such image processing.

Migration of luque rods through a laminectomy defect causing spinal cord compression.

PubMed

Quint, D J; Salton, G

1993-01-01

Internal fixation of traumatic spinal injuries has been associated with spinal canal stenosis, spinal cord compression, and nerve root impingement. We present a case of spinal cord/cauda equina compression due to migration of intact, anchored thoracolumbar Luque rods into the spinal canal through a laminectomy defect, leading to neurologic complications 10 years after the original operation.

Instrumentation and fusion for congenital spine deformities.

PubMed

Hedequist, Daniel J

2009-08-01

A retrospective clinical review. To review the use of modern instrumentation of the spine for congenital spinal deformities. Spinal instrumentation has evolved since the advent of the Harrington rod. There is a paucity of literature, which discusses the use of modern spinal instrumentation in congenital spine deformity cases. This review focuses on modern instrumentation techniques for congenital scoliosis and kyphosis. A systematic review was performed of the literature to discuss spinal implant use for congenital deformities. Spinal instrumentation may be safely and effectively used in cases of congenital spinal deformity. Spinal surgeons taking care of children with congenital spine deformities need to be trained in all aspects of modern spinal instrumentation.

Improvement of spinal alignment and quality of life after corrective surgery for spinal kyphosis in patients with osteoporosis: a comparative study with non-operated patients.

PubMed

Miyakoshi, N; Hongo, M; Kobayashi, T; Abe, T; Abe, E; Shimada, Y

2015-11-01

This study evaluated changes in spinal alignment and quality of life (QOL) after corrective spinal surgery for patients with postmenopausal osteoporosis and spinal kyphosis. Spinal global alignment and QOL were significantly improved after corrective spinal surgery but did not reach the level of non-operated controls. With the increased aging of society, the demand for corrective spinal instrumentation for spinal kyphosis in osteoporotic patients is increasing. However, previous studies have not focused on the improvement of quality of life (QOL) after corrective spinal surgery in patients with osteoporosis, compared to non-operated control patients. The purposes of this study were thus to evaluate changes in spinal alignment and QOL after corrective spinal instrumentation for patients with osteoporosis and spinal kyphosis and to compare these results with non-operated patients. Participants comprised 39 patients with postmenopausal osteoporosis ≥50 years old who underwent corrective spinal surgery using multilevel posterior lumbar interbody fusion (PLIF) for symptomatic thoracolumbar or lumbar kyphosis, and 82 age-matched patients with postmenopausal osteoporosis without prevalent vertebral fractures. Spinopelvic parameters were evaluated with standing lateral spine radiography, and QOL was evaluated with the Japanese Osteoporosis QOL Questionnaire (JOQOL), SF-36, and Roland-Morris Disability Questionnaire (RDQ). Lumbar kyphosis angle, sagittal vertical axis, and pelvic tilt were significantly improved postoperatively. QOL evaluated with all three questionnaires also significantly improved after 6 months postoperatively, particularly in domain and subscale scores for pain and general/mental health. However, these radiographic parameters, total JOQOL score, SF-36 physical component summary score, and RDQ score were significantly inferior compared with non-operated controls. The results indicate that spinal global alignment and QOL were significantly improved after corrective spinal surgery using multilevel PLIF for patients with osteoporosis and spinal kyphosis but did not reach the level of non-operated controls.

Transcranial cerebellar direct current stimulation and transcutaneous spinal cord direct current stimulation as innovative tools for neuroscientists

PubMed Central

Priori, Alberto; Ciocca, Matteo; Parazzini, Marta; Vergari, Maurizio; Ferrucci, Roberta

2014-01-01

Two neuromodulatory techniques based on applying direct current (DC) non-invasively through the skin, transcranial cerebellar direct current stimulation (tDCS) and transcutaneous spinal DCS, can induce prolonged functional changes consistent with a direct influence on the human cerebellum and spinal cord. In this article we review the major experimental works on cerebellar tDCS and on spinal tDCS, and their preliminary clinical applications. Cerebellar tDCS modulates cerebellar motor cortical inhibition, gait adaptation, motor behaviour, and cognition (learning, language, memory, attention). Spinal tDCS influences the ascending and descending spinal pathways, and spinal reflex excitability. In the anaesthetised mouse, DC stimulation applied under the skin along the entire spinal cord may affect GABAergic and glutamatergic systems. Preliminary clinical studies in patients with cerebellar disorders, and in animals and patients with spinal cord injuries, have reported beneficial effects. Overall the available data show that cerebellar tDCS and spinal tDCS are two novel approaches for inducing prolonged functional changes and neuroplasticity in the human cerebellum and spinal cord, and both are new tools for experimental and clinical neuroscientists. PMID:24907311

Morphometric study of the lumbar spinal canal in the Korean population.

PubMed

Lee, H M; Kim, N H; Kim, H J; Chung, I H

1995-08-01

The anatomic dimensions of the vertebral body and spinal canal of the lumbar spine were analyzed in Koreans. To determine the normal dimension of the lumbar spinal canal in Koreans, to determine whether there are any racial differences in the morphometry of the lumbar spinal canal, and to provide criteria for diagnosing spinal stenosis in the Far Eastern Asian. Some radiologic and anatomic studies have been conducted regarding the size of the lumbar spinal canal of whites and blacks in western and African countries. One-thousand-eight-hundred measurements were performed on the transverse and sagittal diameters of vertebral bodies and spinal canals using complete sets of 90 lumbar vertebrae. The mean mid-sagittal diameter of the lumbar spinal canal in the Korean population was less than that measured in white and African populations, but there was no significant differences between the Korean, white, and African populations regarding the transverse diameter of the lumbar spinal canal. The mid-sagittal diameter of the lumbar spinal canal is narrowest in the Far Eastern Asian population; the radiologic criteria of spinal stenosis should be reconsidered for these people.

Plot shape effects on plant species diversity measurements

USGS Publications Warehouse

Keeley, Jon E.; Fotheringham, C.J.

2005-01-01

Abstract. Question: Do rectangular sample plots record more plant species than square plots as suggested by both empirical and theoretical studies?Location: Grasslands, shrublands and forests in the Mediterranean-climate region of California, USA.Methods: We compared three 0.1-ha sampling designs that differed in the shape and dispersion of 1-m2 and 100-m2 nested subplots. We duplicated an earlier study that compared the Whittaker sample design, which had square clustered subplots, with the modified Whittaker design, which had dispersed rectangular subplots. To sort out effects of dispersion from shape we used a third design that overlaid square subplots on the modified Whittaker design. Also, using data from published studies we extracted species richness values for 400-m2 subplots that were either square or 1:4 rectangles partially overlaid on each other from desert scrub in high and low rainfall years, chaparral, sage scrub, oak savanna and coniferous forests with and without fire.Results: We found that earlier empirical reports of more than 30% greater richness with rectangles were due to the confusion of shape effects with spatial effects, coupled with the use of cumulative number of species as the metric for comparison. Average species richness was not significantly different between square and 1:4 rectangular sample plots at either 1- or 100-m2. Pairwise comparisons showed no significant difference between square and rectangular samples in all but one vegetation type, and that one exhibited significantly greater richness with squares. Our three intensive study sites appear to exhibit some level of self-similarity at the scale of 400 m2, but, contrary to theoretical expectations, we could not detect plot shape effects on species richness at this scale.Conclusions: At the 0.1-ha scale or lower there is no evidence that plot shape has predictable effects on number of species recorded from sample plots. We hypothesize that for the mediterranean-climate vegetation types studied here, the primary reason that 1:4 rectangles do not sample greater species richness than squares is because species turnover varies along complex environmental gradients that are both parallel and perpendicular to the long axis of rectangular plots. Reports in the literature of much greater species richness recorded for highly elongated rectangular strips than for squares of the same area are not likely to be fair comparisons because of the dramatically different periphery/area ratio, which includes a much greater proportion of species that are using both above and below-ground niche space outside the sample area.

Neck/upper back and low back pain in parents and their adult offspring: Family linkage data from the Norwegian HUNT Study.

PubMed

Lier, R; Nilsen, T I L; Vasseljen, O; Mork, P J

2015-07-01

Chronic pain in the neck and low back is highly prevalent. Although heritable components have been identified, knowledge about generational transmission of spinal pain between parents and their adult offspring is sparse. This study examined the intergenerational association of spinal pain using data from 11,081 parent-offspring trios participating in the population-based HUNT Study in Norway. Logistic regression was used to calculate adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for offspring spinal pain associated with parental spinal pain. In total, 3654 (33%) offspring reported spinal pain at participation. Maternal and paternal spinal pain was consistently associated with higher ORs for offspring spinal pain. The results suggest a slightly stronger association for parental multilevel spinal pain (i.e., both neck/upper back pain and low back pain) than for pain localized to the neck/upper back or low back. Multilevel spinal pain in both parents was associated with ORs of 2.6 (95% CI, 2.1-3.3), 2.4 (95% CI, 1.9-3.1) and 3.1 (95% CI, 2.2-4.4) for offspring neck/upper back, low back and multilevel spinal pain, respectively. Parental chronic spinal pain was consistently associated with increased occurrence of chronic spinal pain in their adult offspring, and this association was particularly strong for multilevel spinal pain. © 2014 European Pain Federation - EFIC®

Complete segmental resection of the spine, including the spinal cord, for telangiectatic osteosarcoma: a report of 2 cases.

PubMed

Murakami, Hideki; Tomita, Katsuro; Kawahara, Norio; Oda, Makoto; Yahata, Tetsutaro; Yamaguchi, Takehiko

2006-02-15

Two case reports of telangiectatic osteosarcoma treated with complete segmental resection of the spine, including the spinal cord. To report the en bloc tumor excision, including the spinal cord, for telangiectatic osteosarcoma, and discuss the indication of cord transection and influence after cutting the spinal cord. To our knowledge, there are no previous reports describing telangiectatic osteosarcoma of the spine and the subsequent en bloc excision of the spine, including the spinal cord. The clinical and radiographic presentations of 2 cases with telangiectatic osteosarcoma are presented. Because these 2 cases already had complete paralysis for at least 1 month, it was suspected that there was no possibility of recovering spinal cord function. Complete segmental spinal resection (total en bloc spondylectomy) was performed. At that level, the spinal cord was also cut and resected. En bloc excision of the tumor with a wide margin was achieved in both cases. In the resected specimen, the nerve cells in the spinal cord had lapsed into degenerative necrosis. The pathologic findings showed that there was no hope for recovery of spinal cord function. En bloc spinal resection, including the spinal cord, is an operation allowed when there is no hope for recovery of spinal cord function. This surgery should be accepted as an option in spine tumor surgeries.

Hemorrhagic thoracic schwannoma presenting with intradural hematoma and acute paraplegia after spinal manipulation therapy.

PubMed

Hdeib, Alia; Goodwin, C Rory; Sciubba, Daniel; Bydon, Ali; Wolinsky, Jean-Paul; Witham, Timothy; Gokaslan, Ziya L

2016-01-01

Hemorrhagic conversion of spinal schwannomas represents a rare occurrence; also rare is the development of a spinal intradural hematoma after spinal manipulation therapy. We report a unique presentation of paraplegia in a patient who underwent spinal manipulation therapy and was found to have a hemorrhagic thoracic schwannoma at time of surgery in the setting of anti-platelet therapy use. In patients with spinal schwannomas, tumor hemorrhage is a rare occasion, which can be considered in the setting of additive effects of spinal manipulation therapy and antiplatelet therapy.

Anterior spinal artery aneurysm in aortic stenosis of different etiology: Report of three cases.

PubMed

Singh, Vivek; Naik, Suprava; Bhoi, Sanjeev K; Phadke, R V

2017-04-01

Isolated aneurysms of spinal arteries are rare. Spinal artery aneurysms are commonly found in association with spinal cord arteriovenous malformation and coarctation of aorta and rarely with aortic arch interruption and Klippel-Trenaunay syndrome. Spinal angiograms are the gold standard for diagnosing these spinal artery aneurysms but with the advances in computed tomography technology these aneurysms can also be very well demonstrated in computed tomography angiograms. We describe three cases of anterior spinal artery aneurysm, those are flow related aneurysms, associated with coarctation of aorta and with Takayasu arteritis.

Spinal hemianesthesia: Unilateral and posterior

PubMed Central

Imbelloni, Luiz Eduardo

2014-01-01

The injection of a non-isobaric local anesthetic should induce a unilateral spinal anesthesia in patients in a lateral decubitus position. The posterior spinal hemianesthesia only be obtained with hypobaric solutions injected in the jackknife position. The most important factors to be considered when performing a spinal hemianesthesia are: type and gauge of the needle, density of the local anesthetic relative to the CSF, position of the patient, speed of administration of the solution, time of stay in position, and dose/concentration/volume of the anesthetic solution. The distance between the spinal roots on the right-left sides and anterior-posterior is, approximately, 10-15 mm. This distance allows performing unilateral spinal anesthesia or posterior spinal anesthesia. The great advantage of obtaining spinal hemianesthesia is the reduction of cardiovascular changes. Likewise, both the dorsal and unilateral sensory block predominates in relation to the motor block. Because of the numerous advantages of producing spinal hemianesthesia, anesthesiologists should apply this technique more often. This review considers the factors which are relevant, plausible and proven to obtain spinal hemianesthesia. PMID:25886320

[Research progress in the role of aquaproin-4 and inward rectifying potassium channel 4.1 in spinal cord edema].

PubMed

Chen, Tiege; Dang, Yuexiu; Wang, Ming; Zhang, Dongliang; Guo, Yongqiang; Zhang, Haihong

2018-05-28

Spinal edema is a very important pathophysiological basis for secondary spinal cord injury, which affects the repair and prognosis of spinal cord injury. Aquaporin-4 is widely distributed in various organs of the body, and is highly expressed in the brain and spinal cord. Inward rectifying potassium channel 4.1 is a protein found in astrocytes of central nervous system. It interacts with aquaporins in function. Aquaporin-4 and inward rectifying potassium channel 4.1 play an important role in the formation and elimination of spinal cord edema, inhibition of glial scar formation and promotion of excitotoxic agents exclusion. The distribution and function of aquaporin-4 and inward rectifying potassium channel 4.1 in the central nervous system and their expression after spinal cord injury have multiple effects on spinal edema. Studies of aquaporin-4 and inward rectifying potassium channel 4.1 in the spinal cord may provide new ideas for the elimination and treatment of spinal edema.

[Spinal subarachnoid haematoma after spinal anaesthesia: case report].

PubMed

Vidal, Marion; Strzelecki, Antoine; Houadec, Mireille; Krikken, Isabelle Ranz; Danielli, Antoine; Souza Neto, Edmundo Pereira de

2016-01-01

Subarachnoid haematoma after spinal anaesthesia is known to be very rare. In the majority of these cases, spinal anaesthesia was difficult to perform and/or unsuccessful; other risk factors included antiplatelet or anticoagulation therapy, and direct spinal cord trauma. We report a case of subarachnoid haematoma after spinal anaesthesia in a young patient without risk factors. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Spinal subarachnoid haematoma after spinal anaesthesia: case report.

PubMed

Vidal, Marion; Strzelecki, Antoine; Houadec, Mireille; Krikken, Isabelle Ranz; Danielli, Antoine; Souza Neto, Edmundo Pereira de

2016-01-01

Subarachnoid haematoma after spinal anaesthesia is known to be very rare. In the majority of these cases, spinal anaesthesia was difficult to perform and/or unsuccessful; other risk factors included antiplatelet or anticoagulation therapy, and direct spinal cord trauma. We report a case of subarachnoid haematoma after spinal anaesthesia in a young patient without risk factors. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

Computer-assisted spinal osteotomy: a technical note and report of four cases.

PubMed

Fujibayashi, Shunsuke; Neo, Masashi; Takemoto, Mitsuru; Ota, Masato; Nakayama, Tomitaka; Toguchida, Junya; Nakamura, Takashi

2010-08-15

A report of 4 cases of spinal osteotomy performed under the guidance of a computer-assisted navigation system and a technical note about the use of the navigation system for spinal osteotomy. To document the surgical technique and usefulness of computer-assisted surgery for spinal osteotomy. A computer-assisted navigation system provides accurate 3-dimensional (3D) real-time surgical information during the operation. Although there are many reports on the accuracy and usefulness of a navigation system for pedicle screw placement, there are few reports on the application for spinal osteotomy. We report on 4 complex cases including 3 solitary malignant spinal tumors and 1 spinal kyphotic deformity of ankylosing spondylitis, which were treated surgically using a computer-assisted spinal osteotomy. The surgical technique and postoperative clinical and radiologic results are presented. 3D spinal osteotomy under the guidance of a computer-assisted navigation system was performed successfully in 4 patients. All malignant tumors were resected en bloc, and the spinal deformity was corrected precisely according to the preoperative plan. Pathologic analysis confirmed the en bloc resection without tumor exposure in the 3 patients with a spinal tumor. The use of a computer-assisted navigation system will help ensure the safety and efficacy of a complex 3D spinal osteotomy.

A spinal thecal sac constriction model supports the theory that induced pressure gradients in the cord cause edema and cyst formation.

PubMed

Josephson, A; Greitz, D; Klason, T; Olson, L; Spenger, C

2001-03-01

Spinal cord cysts are a devastating condition that occur secondary to obstructions of the spinal canal, which may be caused by congenital malformations, trauma, spinal canal stenosis, tumors, meningitis, or arachnoiditis. A hypothesis that could explain how spinal cord cysts form in these situations has been presented recently. Therefore, a novel spinal thecal sac constriction model was implemented to test various aspects of this hypothesis. Thecal sac constriction was achieved by subjecting rats to an extradural silk ligature at the T8 spinal cord level. Rats with complete spinal cord transection served as a second model for comparison. The animals underwent high-resolution magnetic resonance imaging and histological analysis. Thecal sac constriction caused edema cranial and caudal to the ligation within 3 weeks, and cysts developed after 8 to 13 weeks. In contrast, cysts in rats with spinal cord transection were located predominantly in the cranial spinal cord. Histological sections of spinal cords confirmed the magnetic resonance imaging results. Magnetic resonance imaging provided the specific advantage of enabling characterization of events as they occurred repeatedly over time in the spinal cords of individual living animals. The spinal thecal sac constriction model proved useful for investigation of features of the cerebrospinal fluid pulse pressure theory. Edema and cyst distributions were in accordance with this theory. We conclude that induced intramedullary pressure gradients originating from the cerebrospinal fluid pulse pressure may underlie cyst formation in the vicinity of spinal canal obstructions and that cysts are preceded by edema.

21 CFR 882.5880 - Implanted spinal cord stimulator for pain relief.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Implanted spinal cord stimulator for pain relief. (a) Identification. An implanted spinal cord stimulator for pain relief is a device that is used to stimulate electrically a patient's spinal cord to relieve... on the patient's spinal cord and an external transmitter for transmitting the stimulating pulses...

Restoration of Movement using FES: An Introductory Study I

NASA Astrophysics Data System (ADS)

Ahmed, M.; Huq, M. S.; Ibrahim, B. S. K. K.

2018-03-01

FES has been applied for movement restoration, rehabilitation and therapy in spinal cord injury and nervous system failure subjects, whose number rise worldwide every year. Despite the increase, assist devices that are expected to aid healthcare delivery are not in abundance and could be as a result of standards imposed due to the sensitive condition of the subjects. Although closed loop control systems are expected to positively aid in that regards, the delicacy of the plant was a big constraint. An existing model from the works Ferrarin and Pedotti was elaborated from the knee swinging to the sit-to-stand movements and from the two mathematical models it can be inferred that even though similar higher level of excitation would be required for sit-to-stand manoeuvre. As part of research to improve on closed approach for the FES system, an appraisal was successfully done on the neuromuscular model together with fatigue models from the works on Lynch. The remodelled fatigue models to suit the research were presented.

A silicon central pattern generator controls locomotion in vivo.

PubMed

Vogelstein, R J; Tenore, F; Guevremont, L; Etienne-Cummings, R; Mushahwar, V K

2008-09-01

We present a neuromorphic silicon chip that emulates the activity of the biological spinal central pattern generator (CPG) and creates locomotor patterns to support walking. The chip implements ten integrate-and-fire silicon neurons and 190 programmable digital-to-analog converters that act as synapses. This architecture allows for each neuron to make synaptic connections to any of the other neurons as well as to any of eight external input signals and one tonic bias input. The chip's functionality is confirmed by a series of experiments in which it controls the motor output of a paralyzed animal in real-time and enables it to walk along a three-meter platform. The walking is controlled under closed-loop conditions with the aide of sensory feedback that is recorded from the animal's legs and fed into the silicon CPG. Although we and others have previously described biomimetic silicon locomotor control systems for robots, this is the first demonstration of a neuromorphic device that can replace some functions of the central nervous system in vivo.

MicroRNA filters Hox temporal transcription noise to confer boundary formation in the spinal cord

NASA Astrophysics Data System (ADS)

Li, Chung-Jung; Hong, Tian; Tung, Ying-Tsen; Yen, Ya-Ping; Hsu, Ho-Chiang; Lu, Ya-Lin; Chang, Mien; Nie, Qing; Chen, Jun-An

2017-03-01

The initial rostrocaudal patterning of the neural tube leads to differential expression of Hox genes that contribute to the specification of motor neuron (MN) subtype identity. Although several 3' Hox mRNAs are expressed in progenitors in a noisy manner, these Hox proteins are not expressed in the progenitors and only become detectable in postmitotic MNs. MicroRNA biogenesis impairment leads to precocious expression and propagates the noise of Hoxa5 at the protein level, resulting in an imprecise Hoxa5-Hoxc8 boundary. Here we uncover, using in silico simulation, two feed-forward Hox-miRNA loops accounting for the precocious and noisy Hoxa5 expression, as well as an ill-defined boundary phenotype in Dicer mutants. Finally, we identify mir-27 as a major regulator coordinating the temporal delay and spatial boundary of Hox protein expression. Our results provide a novel trans Hox-miRNA circuit filtering transcription noise and controlling the timing of protein expression to confer robust individual MN identity.

Repression by PRDM13 is critical for generating precision in neuronal identity

PubMed Central

Kollipara, Rahul K; Ma, Zhenzhong; Borromeo, Mark D; Chang, Joshua C

2017-01-01

The mechanisms that activate some genes while silencing others are critical to ensure precision in lineage specification as multipotent progenitors become restricted in cell fate. During neurodevelopment, these mechanisms are required to generate the diversity of neuronal subtypes found in the nervous system. Here we report interactions between basic helix-loop-helix (bHLH) transcriptional activators and the transcriptional repressor PRDM13 that are critical for specifying dorsal spinal cord neurons. PRDM13 inhibits gene expression programs for excitatory neuronal lineages in the dorsal neural tube. Strikingly, PRDM13 also ensures a battery of ventral neural tube specification genes such as Olig1, Olig2 and Prdm12 are excluded dorsally. PRDM13 does this via recruitment to chromatin by multiple neural bHLH factors to restrict gene expression in specific neuronal lineages. Together these findings highlight the function of PRDM13 in repressing the activity of bHLH transcriptional activators that together are required to achieve precise neuronal specification during mouse development. PMID:28850031

Changes in neuronal properties and spinal reflexes during development of spasticity following spinal cord lesions and stroke: studies in animal models and patients.

PubMed

Hultborn, Hans

2003-05-01

It is a well-known fact that spinal reflexes may gradually change and often become enhanced following spinal cord lesions. Although these phenomena are known, the underlying mechanisms are still unknown and under investigation, mainly in animal models. Over the last twenty years, new methods have been developed that can reliably estimate the activity of specific spinal pathways in humans at rest and during voluntary movement. These methods now make it possible to describe components of the spinal pathophysiology in spasticity in humans following spinal lesions or stroke. We now know that spinal networks are capable of generating the basic pattern of locomotion in a large number of vertebrates, including the monkey--and in all likelihood, humans. Although spinal networks are capable of generating locomotor-like activity in the absence of afferent signals, functional gait is not possible without sensory feedback. The results of animal studies on the sensory control of and the transmitter systems involved in the spinal locomotor centers are now being used to improve rehabilitation of walking in persons with spinal cord injury and hemiplegia.

Beliefs in the population about cracking sounds produced during spinal manipulation.

PubMed

Demoulin, Christophe; Baeri, Damien; Toussaint, Geoffrey; Cagnie, Barbara; Beernaert, Axel; Kaux, Jean-François; Vanderthommen, Marc

2018-03-01

To examine beliefs about cracking sounds heard during high-velocity low-amplitude (HVLA) thrust spinal manipulation in individuals with and without personal experience of this technique. We included 100 individuals. Among them, 60 had no history of spinal manipulation, including 40 who were asymptomatic with or without a past history of spinal pain and 20 who had nonspecific spinal pain. The remaining 40 patients had a history of spinal manipulation; among them, 20 were asymptomatic and 20 had spinal pain. Participants attended a one-on-one interview during which they completed a questionnaire about their history of spinal manipulation and their beliefs regarding sounds heard during spinal manipulation. Mean age was 43.5±15.4years. The sounds were ascribed to vertebral repositioning by 49% of participants and to friction between two vertebras by 23% of participants; only 9% of participants correctly ascribed the sound to the formation of a gas bubble in the joint. The sound was mistakenly considered to indicate successful spinal manipulation by 40% of participants. No differences in beliefs were found between the groups with and without a history of spinal manipulation. Certain beliefs have documented adverse effects. This study showed a high prevalence of unfounded beliefs regarding spinal manipulation. These beliefs deserve greater attention from healthcare providers, particularly those who practice spinal manipulation. Copyright © 2017 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

Simultaneous Brain–Cervical Cord fMRI Reveals Intrinsic Spinal Cord Plasticity during Motor Sequence Learning

PubMed Central

Cohen-Adad, Julien; Marchand-Pauvert, Veronique; Benali, Habib; Doyon, Julien

2015-01-01

The spinal cord participates in the execution of skilled movements by translating high-level cerebral motor representations into musculotopic commands. Yet, the extent to which motor skill acquisition relies on intrinsic spinal cord processes remains unknown. To date, attempts to address this question were limited by difficulties in separating spinal local effects from supraspinal influences through traditional electrophysiological and neuroimaging methods. Here, for the first time, we provide evidence for local learning-induced plasticity in intact human spinal cord through simultaneous functional magnetic resonance imaging of the brain and spinal cord during motor sequence learning. Specifically, we show learning-related modulation of activity in the C6–C8 spinal region, which is independent from that of related supraspinal sensorimotor structures. Moreover, a brain–spinal cord functional connectivity analysis demonstrates that the initial linear relationship between the spinal cord and sensorimotor cortex gradually fades away over the course of motor sequence learning, while the connectivity between spinal activity and cerebellum gains strength. These data suggest that the spinal cord not only constitutes an active functional component of the human motor learning network but also contributes distinctively from the brain to the learning process. The present findings open new avenues for rehabilitation of patients with spinal cord injuries, as they demonstrate that this part of the central nervous system is much more plastic than assumed before. Yet, the neurophysiological mechanisms underlying this intrinsic functional plasticity in the spinal cord warrant further investigations. PMID:26125597

The beneficial effects of treadmill step training on activity-dependent synaptic and cellular plasticity markers after complete spinal cord injury.

PubMed

Ilha, Jocemar; Centenaro, Lígia A; Broetto Cunha, Núbia; de Souza, Daniela F; Jaeger, Mariane; do Nascimento, Patrícia S; Kolling, Janaína; Ben, Juliana; Marcuzzo, Simone; Wyse, Angela T S; Gottfried, Carmem; Achaval, Matilde

2011-06-01

Several studies have shown that treadmill training improves neurological outcomes and promotes plasticity in lumbar spinal cord of spinal animals. The morphological and biochemical mechanisms underlying these phenomena remain unclear. The purpose of this study was to provide evidence of activity-dependent plasticity in spinal cord segment (L5) below a complete spinal cord transection (SCT) at T8-9 in rats in which the lower spinal cord segments have been fully separated from supraspinal control and that subsequently underwent treadmill step training. Five days after SCT, spinal animals started a step-training program on a treadmill with partial body weight support and manual step help. Hindlimb movements were evaluated over time and scored on the basis of the open-field BBB scale and were significantly improved at post-injury weeks 8 and 10 in trained spinal animals. Treadmill training also showed normalization of withdrawal reflex in trained spinal animals, which was significantly different from the untrained animals at post-injury weeks 8 and 10. Additionally, compared to controls, spinal rats had alpha motoneuronal soma size atrophy and reduced synaptophysin protein expression and Na(+), K(+)-ATPase activity in lumbar spinal cord. Step-trained rats had motoneuronal soma size, synaptophysin expression and Na(+), K(+)-ATPase activity similar to control animals. These findings suggest that treadmill step training can promote activity-dependent neural plasticity in lumbar spinal cord, which may lead to neurological improvements without supraspinal descending control after complete spinal cord injury.

Simultaneous Brain-Cervical Cord fMRI Reveals Intrinsic Spinal Cord Plasticity during Motor Sequence Learning.

PubMed

Vahdat, Shahabeddin; Lungu, Ovidiu; Cohen-Adad, Julien; Marchand-Pauvert, Veronique; Benali, Habib; Doyon, Julien

2015-06-01

The spinal cord participates in the execution of skilled movements by translating high-level cerebral motor representations into musculotopic commands. Yet, the extent to which motor skill acquisition relies on intrinsic spinal cord processes remains unknown. To date, attempts to address this question were limited by difficulties in separating spinal local effects from supraspinal influences through traditional electrophysiological and neuroimaging methods. Here, for the first time, we provide evidence for local learning-induced plasticity in intact human spinal cord through simultaneous functional magnetic resonance imaging of the brain and spinal cord during motor sequence learning. Specifically, we show learning-related modulation of activity in the C6-C8 spinal region, which is independent from that of related supraspinal sensorimotor structures. Moreover, a brain-spinal cord functional connectivity analysis demonstrates that the initial linear relationship between the spinal cord and sensorimotor cortex gradually fades away over the course of motor sequence learning, while the connectivity between spinal activity and cerebellum gains strength. These data suggest that the spinal cord not only constitutes an active functional component of the human motor learning network but also contributes distinctively from the brain to the learning process. The present findings open new avenues for rehabilitation of patients with spinal cord injuries, as they demonstrate that this part of the central nervous system is much more plastic than assumed before. Yet, the neurophysiological mechanisms underlying this intrinsic functional plasticity in the spinal cord warrant further investigations.

Spinal injury - resources

MedlinePlus

Resources - spinal injury ... The following organizations are good resources for information on spinal injury : National Institute of Neurological Disorders and Stroke -- www.ninds.nih.gov/Disorders/All-Disorders/Spinal-Cord- ...

Cost Effectiveness Tradeoffs in Computer Standardization and Technology Insertion.

DTIC Science & Technology

1986-06-01

S MONITORING ORGANIZATION REPORT NUMBER(S) P-1931 6aNAME OF PERFORMING ORGANIZATION 16b OFFICE SYMBOL 7a NAME oF MONITORIG ORGANIZAIO0N Institute for...shown in the figure, is a circle with a symbolic V"valve" on top controlling a flow arrow that goes between a symbolic " cloud " (that also resembles a four...leaf clover) and the rectangle which represents the level. If the rate is an inflow, the arrow points to the level and the cloud is called a source

Direct and Quantitative Characterization of Dynamic Ligand Exchange between Coordination-Driven Self-Assembled Supramolecular Polygons

PubMed Central

Zheng, Yao-Rong; Stang, Peter J.

2009-01-01

The direct observation of dynamic ligand exchange beween Pt-N coordination-driven self-assembled supramolecular polygons (triangles and rectangles) has been achieved using stable isotope labeling (1H/2D) of the pyridyl donors and electrospray ionization mass spectrometry (ESI-MS) together with NMR spectroscopy. Both the thermodynamic and kinetic aspects of such exchange processes have been established based on quantitative mass spectral results. Further investigation showed that the exchange is highly dependent on experimental conditions such as temperature, solvent, and the counter anions. PMID:19243144

Direct and quantitative characterization of dynamic ligand exchange between coordination-driven self-assembled supramolecular polygons.

PubMed

Zheng, Yao-Rong; Stang, Peter J

2009-03-18

The direct observation of dynamic ligand exchange between Pt-N coordination-driven self-assembled supramolecular polygons (triangles and rectangles) has been achieved using stable (1)H/(2)D isotope labeling of the pyridyl donors and electrospray ionization mass spectrometry combined with NMR spectroscopy. Both the thermodynamic and kinetic aspects of such exchange processes have been established on the basis of quantitative mass spectral results. Further investigation has shown that the exchange is highly dependent on experimental conditions such as temperature, solvent, and the counteranions.

Effect of Specimen Thickness on the Creep Response of a Single Crystal Superalloy (Preprint)

DTIC Science & Technology

2012-01-01

0.38mm. 3.1.2. Fractography Figure 5: SEM images of the sheet specimen of thickness 3.18mm creep tested at 760◦C/758MPa, (a) Specimen reconstructed after...with dotted rectangle in (b). To further explore the mechanism behind thickness debit effect, we performed stan- dard fractography using secondary...thickness 3.18mm ruptured after 210hours. 3.2.3. Fractography The SEM image of the reconstructed creep ruptured specimen of thickness 3.18mm is shown in

Electronic bypass of spinal lesions: activation of lower motor neurons directly driven by cortical neural signals.

PubMed

Li, Yan; Alam, Monzurul; Guo, Shanshan; Ting, K H; He, Jufang

2014-07-03

Lower motor neurons in the spinal cord lose supraspinal inputs after complete spinal cord injury, leading to a loss of volitional control below the injury site. Extensive locomotor training with spinal cord stimulation can restore locomotion function after spinal cord injury in humans and animals. However, this locomotion is non-voluntary, meaning that subjects cannot control stimulation via their natural "intent". A recent study demonstrated an advanced system that triggers a stimulator using forelimb stepping electromyographic patterns to restore quadrupedal walking in rats with spinal cord transection. However, this indirect source of "intent" may mean that other non-stepping forelimb activities may false-trigger the spinal stimulator and thus produce unwanted hindlimb movements. We hypothesized that there are distinguishable neural activities in the primary motor cortex during treadmill walking, even after low-thoracic spinal transection in adult guinea pigs. We developed an electronic spinal bridge, called "Motolink", which detects these neural patterns and triggers a "spinal" stimulator for hindlimb movement. This hardware can be head-mounted or carried in a backpack. Neural data were processed in real-time and transmitted to a computer for analysis by an embedded processor. Off-line neural spike analysis was conducted to calculate and preset the spike threshold for "Motolink" hardware. We identified correlated activities of primary motor cortex neurons during treadmill walking of guinea pigs with spinal cord transection. These neural activities were used to predict the kinematic states of the animals. The appropriate selection of spike threshold value enabled the "Motolink" system to detect the neural "intent" of walking, which triggered electrical stimulation of the spinal cord and induced stepping-like hindlimb movements. We present a direct cortical "intent"-driven electronic spinal bridge to restore hindlimb locomotion after complete spinal cord injury.

Reinforcement of spinal anesthesia by epidural injection of saline: a comparison of hyperbaric and isobaric tetracaine.

PubMed

Yamazaki, Y; Mimura, M; Hazama, K; Namiki, A

2000-04-25

An epidural injection of saline was reported to extend spinal anesthesia because of a volume effect. The aim of this study was to evaluate the influence of the baricity of spinal local anesthetics upon the extension of spinal anesthesia by epidural injection of saline. Forty patients undergoing elective lower-limb surgery were randomly allocated to four groups of 10 patients each. Group A received no epidural injection after the spinal administration of hyperbaric tetracaine (dissolved in 10% glucose). Group B received an epidural injection of 8 ml of physiological saline 20 min after spinal hyperbaric tetracaine. Group C received no epidural injection after spinal isobaric tetracaine (dissolved in physiological saline). Group D received an epidural injection of 8 ml of saline 20 min after spinal isobaric tetracaine. The level of analgesia was examined by the pinprick method at 5-min intervals. The levels of analgesia 20 min after spinal anesthesia were significantly higher in hyperbaric groups than in isobaric groups [T5 (T2-L2) vs. T7 (T3-12)]. After epidural injection of saline, the levels of analgesia in groups B and D were significantly higher than in groups A and C. The segmental increases after epidural saline injection were 2 (0-3) in group B and 2 (1-7) in group D. Sensation in the sacral area remained 20 min after spinal block in one patient in group D; however, it disappeared after epidural saline injection. In this study, 8 ml of epidural saline extended spinal analgesia. However, there was no difference between the augmenting effect in isobaric and hyperbaric spinal anesthesia. We conclude that the reinforcement of spinal anesthesia by epidural injection of saline is not affected by the baricity of the spinal anesthetic solution used.

Ablating spinal NK1-bearing neurons eliminates the development of pain & reduces spinal neuronal hyperexcitability & inflammation from mechanical joint injury in the rat

PubMed Central

Weisshaar, Christine L.; Winkelstein, Beth A.

2014-01-01

The facet joint is a common source of pain especially from mechanical injury. Although chronic pain is associated with altered spinal glial and neuronal responses, the contribution of specific spinal cells to joint pain are not understood. This study used the neurotoxin [Sar9,Met(O2)11]-substance P-saporin (SSP-SAP) to selectively eliminate spinal cells expressing neurokinin-1 receptor (NK1R) in a rat model of painful facet joint injury to determine the role of those spinal neurons in pain from facet injury. Following spinal administration of SSP-SAP or its control (blank-SAP), a cervical facet injury was imposed and behavioral sensitivity assessed. Spinal extracellular recordings were made on day 7 to classify neurons and quantify evoked firing. Spinal glial activation and IL1α expression also were evaluated. SSP-SAP prevented the development of mechanical hyperalgesia that is induced by joint injury and reduced NK1R expression and mechanically-evoked neuronal firing in the dorsal horn. SSP-SAP also prevented a shift toward wide dynamic range neurons that is seen after injury. Spinal astrocytic activation and IL1α expression were reduced to sham levels with SSP-SAP treatment. These results suggest that spinal NK1R-bearing cells are critical in initiating spinal nociception and inflammation associated with a painful mechanical joint injury. Perspective Results demonstrate that cells expressing NK1R in the spinal cord are critical for the development of joint pain and spinal neuroplasticity and inflammation after trauma to the joint. These findings have utility for understanding mechanisms of joint pain and developing potential targets to treat pain. PMID:24389017

Directing Spinal Cord Plasticity: The Impact of Stretch Therapy on Functional Recovery after Spinal Cord Injury

DTIC Science & Technology

2015-10-01

AWARD NUMBER: W81XWH-12-1-0587 TITLE: Directing Spinal Cord Plasticity: The Impact of Stretch Therapy on Functional Recovery after Spinal Cord...3. DATES COVERED (From - To) 30Sep2014 - 29Sep2015 4. TITLE AND SUBTITLE Directing Spinal Cord Plasticity: The Impact of Stretch Therapy on...ABSTRACT Essentially all spinal cord injured patients receive stretching therapies beginning within the first few weeks post-injury. Despite this fact

Recovery of locomotion in the cat following spinal cord lesions.

PubMed

Rossignol, S; Bouyer, L; Barthélemy, D; Langlet, C; Leblond, H

2002-10-01

In most species, locomotor function beneath the level of a spinal cord lesion can be restored even if the cord is completely transected. This suggests that there is, within the spinal cord, an autonomous network of neurons capable of generating a locomotor pattern independently of supraspinal inputs. Recent studies suggest that several physiological and neurochemical changes have to occur in the neuronal networks located caudally to the lesion to allow the expression of spinal locomotion. Some evidence of this plasticity will be addressed in this review. In addition, original data on the functional organisation of the lumbar spinal cord will also be presented. Recent works in our lab show that segmental responsiveness of the spinal cord of the cat to locally micro-injected drugs in different lumbar segments, in combination with complete lesions at various level of the spinal cord, suggest a rostro-caudal organisation of spinal locomotor control. Moreover, the integrity of midlumbar segments seems to be crucial for the expression of spinal locomotion. These data suggest that the regions of critical importance for locomotion can be confined to a restricted portion of the spinal cord. Later, these midlumbar segments could be targeted by electrical stimulation or grafts to improve recovery of function. Understanding the changes in spinal cord neurophysiology and neurochemistry after a lesion is of critical importance to the improvement of treatments for locomotor rehabilitation in spinal-cord-injured patients.

Spinal cord injury arising in anaesthesia practice.

PubMed

Hewson, D W; Bedforth, N M; Hardman, J G

2018-01-01

Spinal cord injury arising during anaesthetic practice is a rare event, but one that carries a significant burden in terms of morbidity and mortality. In this article, we will review the pathophysiology of spinal cord injury. We will then discuss injuries relating to patient position, spinal cord hypoperfusion and neuraxial techniques. The most serious causes of spinal cord injury - vertebral canal haematoma, spinal epidural abscess, meningitis and adhesive arachnoiditis - will be discussed in turn. For each condition, we draw attention to practical, evidence-based measures clinicians can undertake to reduce their incidence, or mitigate their severity. Finally, we will discuss transient neurological symptoms. Some cases of spinal cord injury during anaesthesia can be ascribed to anaesthesia itself, arising as a direct consequence of its conduct. The injury to a spinal nerve root by inaccurate and/or incautious needling during spinal anaesthesia is an obvious example. But in many cases, spinal cord injury during anaesthesia is not caused by, related to, or even associated with, the conduct of the anaesthetic. Surgical factors, whether direct (e.g. spinal nerve root damage due to incorrect pedicle screw placement) or indirect (e.g. cord ischaemia following aortic surgery) are responsible for a significant proportion of spinal cord injuries that occur concurrently with the delivery of regional or general anaesthesia. © 2018 The Association of Anaesthetists of Great Britain and Ireland.

Role of spinal p38α and β MAPK in inflammatory hyperalgesia and spinal COX-2 expression

PubMed Central

Fitzsimmons, Bethany L.; Zattoni, Michela; Svensson, Camilla I.; Steinauer, Joanne; Hua, Xiao-Ying; Yaksh, Tony L.

2010-01-01

Pharmacological studies indicate that spinal p38 MAPK plays a role in the development of hyperalgesia. We investigated whether either the spinal isoform p38α or p38β is involved in peripheral inflammation-evoked pain state and increased expression of spinal COX-2. Using intrathecal antisense oligonucleotides, we show that hyperalgesia is prevented by downregulation of p38β but not p38α, while increases in spinal COX-2 protein expression at eight hours is mediated by both p38α and β isoforms. These data suggest that early activation of spinal p38β isoform may affect acute facilitatory processing, and both p38β and α isforms mediate temporally delayed upregulation of spinal COX-2. PMID:20134354

Dynamic biomechanical examination of the lumbar spine with implanted total spinal segment replacement (TSSR) utilizing a pendulum testing system.

PubMed

Daniels, Alan H; Paller, David J; Koruprolu, Sarath; Palumbo, Mark A; Crisco, Joseph J

2013-01-01

Biomechanical investigations of spinal motion preserving implants help in the understanding of their in vivo behavior. In this study, we hypothesized that the lumbar spine with implanted total spinal segment replacement (TSSR) would exhibit decreased dynamic stiffness and more rapid energy absorption compared to native functional spinal units under simulated physiologic motion when tested with the pendulum system. Five unembalmed, frozen human lumbar functional spinal units were tested on the pendulum system with axial compressive loads of 181 N, 282 N, 385 N, and 488 N before and after Flexuspine total spinal segment replacement implantation. Testing in flexion, extension, and lateral bending began by rotating the pendulum to 5°; resulting in unconstrained oscillatory motion. The number of rotations to equilibrium was recorded and bending stiffness (N-m/°) was calculated and compared for each testing mode. The total spinal segment replacement reached equilibrium with significantly fewer cycles to equilibrium compared to the intact functional spinal unit at all loads in flexion (p<0.011), and at loads of 385 N and 488 N in lateral bending (p<0.020). Mean bending stiffness in flexion, extension, and lateral bending increased with increasing load for both the intact functional spinal unit and total spinal segment replacement constructs (p<0.001), with no significant differences in stiffness between the intact functional spinal unit and total spinal segment replacement in any of the test modes (p>0.18). Lumbar functional spinal units with implanted total spinal segment replacement were found to have similar dynamic bending stiffness, but absorbed energy at a more rapid rate than intact functional spinal units during cyclic loading with an unconstrained pendulum system. Although the effects on clinical performance of motion preserving devices is not fully known, these results provide further insight into the biomechanical behavior of this device under approximated physiologic loading conditions.

Dynamic Biomechanical Examination of the Lumbar Spine with Implanted Total Spinal Segment Replacement (TSSR) Utilizing a Pendulum Testing System

PubMed Central

Daniels, Alan H.; Paller, David J.; Koruprolu, Sarath; Palumbo, Mark A.; Crisco, Joseph J.

2013-01-01

Background Biomechanical investigations of spinal motion preserving implants help in the understanding of their in vivo behavior. In this study, we hypothesized that the lumbar spine with implanted total spinal segment replacement (TSSR) would exhibit decreased dynamic stiffness and more rapid energy absorption compared to native functional spinal units under simulated physiologic motion when tested with the pendulum system. Methods Five unembalmed, frozen human lumbar functional spinal units were tested on the pendulum system with axial compressive loads of 181 N, 282 N, 385 N, and 488 N before and after Flexuspine total spinal segment replacement implantation. Testing in flexion, extension, and lateral bending began by rotating the pendulum to 5°; resulting in unconstrained oscillatory motion. The number of rotations to equilibrium was recorded and bending stiffness (N-m/°) was calculated and compared for each testing mode. Results The total spinal segment replacement reached equilibrium with significantly fewer cycles to equilibrium compared to the intact functional spinal unit at all loads in flexion (p<0.011), and at loads of 385 N and 488 N in lateral bending (p<0.020). Mean bending stiffness in flexion, extension, and lateral bending increased with increasing load for both the intact functional spinal unit and total spinal segment replacement constructs (p<0.001), with no significant differences in stiffness between the intact functional spinal unit and total spinal segment replacement in any of the test modes (p>0.18). Conclusions Lumbar functional spinal units with implanted total spinal segment replacement were found to have similar dynamic bending stiffness, but absorbed energy at a more rapid rate than intact functional spinal units during cyclic loading with an unconstrained pendulum system. Although the effects on clinical performance of motion preserving devices is not fully known, these results provide further insight into the biomechanical behavior of this device under approximated physiologic loading conditions. PMID:23451222

SU-E-T-255: Optimized Supine Craniospinal Irradiation with Image-Guided and Field Matched Beams

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

Jiang, Z; Holupka, E; Naughton, J

2014-06-01

Purpose: Conventional craniospinal irradiation (CSI) challenges include dose inhomogeneity at field junctions and position uncertainty due to the field divergence, particular for the two spinal fields. Here we outline a new supine CSI technique to address these difficulties. Methods: Patient was simulated in supine position. The cranial fields had isocenter at C2/C3 vertebral and were matched with 1st spinal field. Their inferior border was chosen to avoid the shoulder, as well as chin from the 1st spine field. Their collimator angles were dependent on asymmetry jaw setting of the 1st spinal field. With couch rotation, the spinal field gantry anglesmore » were adjusted to ensure, the inferior border of 1st and superior border of 2nd spinal fields were perpendicular to the table top. The radio-opaque wire position for the spinal junction was located initially by the light field from an anterior setup beam, and was finalized by the portal imaging of the 1st spinal field. With reference to the spinal junction wire, the fields were matched by positioning the isocenter of the 2nd spinal field. A formula was derived to optimize supine CSI treatment planning, by utilizing the relationship among the Yjaw setting, the spinal field gantry angles, cranial field collimator angles, and the spinal field isocenters location. The plan was delivered with portal imaging alignment for the both cranial and spinal junctions. Results: Utilizing this technique with matching beams, and conventional technique such as feathering and forwarding planning, a homogenous dose distribution was achieved throughout the entire CSI treatment volume including the spinal junction. Placing the spinal junction wire visualized in both spinal portals, allows for precise determination and verification of the appropriate match line of the spine fields. Conclusion: This technique of optimization supine CSI achieved a homogenous dose distributions and patient localization accuracy with image-guided and matched beams.« less

The Spinal Instability Neoplastic Score: Impact on Oncologic Decision-Making.

PubMed

Versteeg, Anne L; Verlaan, Jorrit-Jan; Sahgal, Arjun; Mendel, Ehud; Quraishi, Nasir A; Fourney, Daryl R; Fisher, Charles G

2016-10-15

Systematic literature review. To address the following questions in a systematic literature review: 1. How is spinal neoplastic instability defined or classified in the literature before and after the introduction of the Spinal Instability Neoplastic Score (SINS)? 2. How has SINS affected daily clinical practice? 3. Can SINS be used as a prognostic tool? Spinal neoplastic-related instability was defined in 2010 and simultaneously SINS was introduced as a novel tool with criteria agreed upon by expert consensus to assess the degree of spinal stability. PubMed, Embase, and clinical trial databases were searched with the key words "spinal neoplasm," "spinal instability," "spinal instability neoplastic score," and synonyms. Studies describing spinal neoplastic-related instability were eligible for inclusion. Primary outcomes included studies describing and/or defining neoplastic-related instability, SINS, and studies using SINS as a prognostic factor. The search identified 1414 articles, of which 51 met the inclusion criteria. No precise definition or validated assessment tool was used specific to spinal neoplastic-related instability prior to the introduction of SINS. Since the publication of SINS in 2010, the vast majority of the literature regarding spinal instability has used SINS to assess or describe instability. Twelve studies specifically investigated the prognostic value of SINS in patients who underwent radiotherapy or surgery. No consensus could be determined regarding the definition, assessment, or reporting of neoplastic-related instability before introduction of SINS. Defining spinal neoplastic-related instability and the introduction of SINS have led to improved uniform reporting within the spinal neoplastic literature. Currently, the prognostic value of SINS is controversial. N/A.

Protrusion of a rod into the spinal canal 10 years after segmental lumbar spine surgery.

PubMed

Cai, Siyi; Kong, Xiangyi; Yan, Chengrui; Wang, Yipeng; Wan, Xueshuai; Zhang, Jialu; Qiu, Guixing; Yu, Keyi

2017-03-01

The objective of this article is to report an unusual case of a spinal rod that protruded into the spinal canal after lumbar spine surgery.Only 4 cases of spinal rod migration with protrusion into the spinal canal have been reported. This is the first report of a case involving the use of posterior low lumbar segmental instrumentation with a screw-rod system. The left side of the rod gradually migrated and finally protruded into the canal and compressed the cord.A 60-year-old woman presented with pain and numbness of the posterior aspect of the left leg after a long-distance walk. Intermittent claudication became worse, and she developed pain and numbness in the perineal region. An x-ray showed that the left side of a spinal rod among the segmental spinal instruments that had been placed 10 years previously had protruded into the spinal canal.We removed the rod and decompressed the canal at the level of L5-S1. The patient became totally asymptomatic.Rods used as spinal instrumentation have the possibility of protruding into the spinal canal and endangering the nervous system. Long-term follow-up with radiological examinations should be conducted upon completion of spinal operations conducting using instrumentation.

Meningocele repair - series (image)

MedlinePlus

... containing a portion of the spinal cord membrane (meninges), spinal fluid, and a portion of spinal cord ... The spinal cord is covered with the membranes (meninges) and the skin is closed over the protruding ...

Transcutaneous spinal direct current stimulation of the lumbar and sacral spinal cord: a modelling study

NASA Astrophysics Data System (ADS)

Fernandes, Sofia R.; Salvador, Ricardo; Wenger, Cornelia; de Carvalho, Mamede; Miranda, Pedro C.

2018-06-01

Objective. Our aim was to perform a computational study of the electric field (E-field) generated by transcutaneous spinal direct current stimulation (tsDCS) applied over the thoracic, lumbar and sacral spinal cord, in order to assess possible neuromodulatory effects on spinal cord circuitry related with lower limb functions. Approach. A realistic volume conductor model of the human body consisting of 14 tissues was obtained from available databases. Rubber pad electrodes with a metallic connector and a conductive gel layer were modelled. The finite element (FE) method was used to calculate the E-field when a current of 2.5 mA was passed between two electrodes. The main characteristics of the E-field distributions in the spinal grey matter (spinal-GM) and spinal white matter (spinal-WM) were compared for seven montages, with the anode placed either over T10, T8 or L2 spinous processes (s.p.), and the cathode placed over right deltoid (rD), umbilicus (U) and right iliac crest (rIC) areas or T8 s.p. Anisotropic conductivity of spinal-WM and of a group of dorsal muscles near the vertebral column was considered. Main results. The average E-field magnitude was predicted to be above 0.15 V m-1 in spinal cord regions located between the electrodes. L2-T8 and T8-rIC montages resulted in the highest E-field magnitudes in lumbar and sacral spinal segments (>0.30 V m-1). E-field longitudinal component is 3 to 6 times higher than the ventral-dorsal and right-left components in both the spinal-GM and WM. Anatomical features such as CSF narrowing due to vertebrae bony edges or disks intrusions in the spinal canal correlate with local maxima positions. Significance. Computational modelling studies can provide detailed information regarding the electric field in the spinal cord during tsDCS. They are important to guide the design of clinical tsDCS protocols that optimize stimulation of application-specific spinal targets.

Earthquake-related versus non-earthquake-related injuries in spinal injury patients: differentiation with multidetector computed tomography

PubMed Central

2010-01-01

Introduction In recent years, several massive earthquakes have occurred across the globe. Multidetector computed tomography (MDCT) is reliable in detecting spinal injuries. The purpose of this study was to compare the features of spinal injuries resulting from the Sichuan earthquake with those of non-earthquake-related spinal trauma using MDCT. Methods Features of spinal injuries of 223 Sichuan earthquake-exposed patients and 223 non-earthquake-related spinal injury patients were retrospectively compared using MDCT. The date of non-earthquake-related spinal injury patients was collected from 1 May 2009 to 22 July 2009 to avoid the confounding effects of seasonal activity and clothing. We focused on anatomic sites, injury types and neurologic deficits related to spinal injuries. Major injuries were classified according to the grid 3-3-3 scheme of the Magerl (AO) classification system. Results A total of 185 patients (82.96%) in the earthquake-exposed cohort experienced crush injuries. In the earthquake and control groups, 65 and 92 patients, respectively, had neurologic deficits. The anatomic distribution of these two cohorts was significantly different (P < 0.001). Cervical spinal injuries were more common in the control group (risk ratio (RR) = 2.12, P < 0.001), whereas lumbar spinal injuries were more common in the earthquake-related spinal injuries group (277 of 501 injured vertebrae; 55.29%). The major types of injuries were significantly different between these cohorts (P = 0.002). Magerl AO type A lesions composed most of the lesions seen in both of these cohorts. Type B lesions were more frequently seen in earthquake-related spinal injuries (RR = 1.27), while we observed type C lesions more frequently in subjects with non-earthquake-related spinal injuries (RR = 1.98, P = 0.0029). Conclusions Spinal injuries sustained in the Sichuan earthquake were located mainly in the lumbar spine, with a peak prevalence of type A lesions and a high occurrence of neurologic deficits. The anatomic distribution and type of spinal injuries that varied between earthquake-related and non-earthquake-related spinal injury groups were perhaps due to the different mechanism of injury. PMID:21190568

Testosterone Plus Finasteride Treatment After Spinal Cord Injury

ClinicalTrials.gov

2018-05-16

Spinal Cord Injury; Spinal Cord Injuries; Trauma, Nervous System; Wounds and Injuries; Central Nervous System Diseases; Nervous System Diseases; Spinal Cord Diseases; Gonadal Disorders; Endocrine System Diseases; Hypogonadism; Genital Diseases, Male

Update on traumatic acute spinal cord injury. Part 2.

PubMed

Mourelo Fariña, M; Salvador de la Barrera, S; Montoto Marqués, A; Ferreiro Velasco, M E; Galeiras Vázquez, R

The aim of treatment in acute traumatic spinal cord injury is to preserve residual neurologic function, avoid secondary injury, and restore spinal alignment and stability. In this second part of the review, we describe the management of spinal cord injury focusing on issues related to short-term respiratory management, where the preservation of diaphragmatic function is a priority, with prediction of the duration of mechanical ventilation and the need for tracheostomy. Surgical assessment of spinal injuries based on updated criteria is discussed, taking into account that although the type of intervention depends on the surgical team, nowadays treatment should afford early spinal decompression and stabilization. Within a comprehensive strategy in spinal cord injury, it is essential to identify and properly treat patient anxiety and pain associated to spinal cord injury, as well as to prevent and ensure the early diagnosis of complications secondary to spinal cord injury (thromboembolic disease, gastrointestinal and urinary disorders, pressure ulcers). Copyright © 2016 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

Spinal stenosis presenting as "the postpolio syndrome". Review of four cases.

PubMed

LaBan, M M; Sanitate, S S; Taylor, R S

1993-12-01

The diagnosis of postpolio syndrome is based primarily on a thorough history supported by both clinical and laboratory examination. Similarly, the presence of an occult spinal stenosis may be suspected initially by a history of progressive lumbar or cervical radicular pain, as well as concomitant extremity weakness and/or myelopathic signs. Appropriate electrodiagnostic examinations, including somatosensory spinal-evoked potentials and electroneuromyography, as well as imaging studies, computer-assisted tomography scan, magnetic resonance imaging and/or myelography are all useful in confirming the clinical diagnosis of either cervical spinal stenosis or lumbar spinal stenosis in patients who also may have had a history of poliomyelitis. Four patients (three men and one woman) previously diagnosed as having postpolio syndrome were referred with predominate complaints of spinal and extremity pain as well as associated motor weakness. It was subsequently recognized that these patients, ranging in age from 45-65 yr, were actually presenting with symptomatic spinal stenosis. It was discovered that two patients had cervical spinal stenosis; the other two had lumbar spinal stenosis.

The Animal Model of Spinal Cord Injury as an Experimental Pain Model

PubMed Central

Nakae, Aya; Nakai, Kunihiro; Yano, Kenji; Hosokawa, Ko; Shibata, Masahiko; Mashimo, Takashi

2011-01-01

Pain, which remains largely unsolved, is one of the most crucial problems for spinal cord injury patients. Due to sensory problems, as well as motor dysfunctions, spinal cord injury research has proven to be complex and difficult. Furthermore, many types of pain are associated with spinal cord injury, such as neuropathic, visceral, and musculoskeletal pain. Many animal models of spinal cord injury exist to emulate clinical situations, which could help to determine common mechanisms of pathology. However, results can be easily misunderstood and falsely interpreted. Therefore, it is important to fully understand the symptoms of human spinal cord injury, as well as the various spinal cord injury models and the possible pathologies. The present paper summarizes results from animal models of spinal cord injury, as well as the most effective use of these models. PMID:21436995

Genetically identified spinal interneurons integrating tactile afferents for motor control

PubMed Central

Panek, Izabela; Farah, Carl

2015-01-01

Our movements are shaped by our perception of the world as communicated by our senses. Perception of sensory information has been largely attributed to cortical activity. However, a prior level of sensory processing occurs in the spinal cord. Indeed, sensory inputs directly project to many spinal circuits, some of which communicate with motor circuits within the spinal cord. Therefore, the processing of sensory information for the purpose of ensuring proper movements is distributed between spinal and supraspinal circuits. The mechanisms underlying the integration of sensory information for motor control at the level of the spinal cord have yet to be fully described. Recent research has led to the characterization of spinal neuron populations that share common molecular identities. Identification of molecular markers that define specific populations of spinal neurons is a prerequisite to the application of genetic techniques devised to both delineate the function of these spinal neurons and their connectivity. This strategy has been used in the study of spinal neurons that receive tactile inputs from sensory neurons innervating the skin. As a result, the circuits that include these spinal neurons have been revealed to play important roles in specific aspects of motor function. We describe these genetically identified spinal neurons that integrate tactile information and the contribution of these studies to our understanding of how tactile information shapes motor output. Furthermore, we describe future opportunities that these circuits present for shedding light on the neural mechanisms of tactile processing. PMID:26445867

Does a paresthesia during spinal needle insertion indicate intrathecal needle placement?

PubMed

Pong, Ryan P; Gmelch, Benjamin S; Bernards, Christopher M

2009-01-01

Paresthesias are relatively common during spinal needle insertion, however, the clinical significance of the paresthesia is unknown. A paresthesia may result from needle-to-nerve contact with a spinal nerve in the epidural space, or, with far lateral needle placement, may result from contact with a spinal nerve within the intervertebral foramen. However, it is also possible and perhaps more likely, that paresthesias occur when the spinal needle contacts a spinal nerve root within the subarachnoid space. This study was designed to test this latter hypothesis. Patients (n = 104) scheduled for surgery under spinal anesthesia were observed during spinal needle insertion. If a paresthesia occurred, the needle was fixed in place and the stylet removed to observe whether cerebrospinal fluid (CSF) flowed from the hub. The presence of CSF was considered proof that the needle had entered the subarachnoid space. Paresthesias occurred in 14/103 (13.6%) of patients; 1 patient experienced a paresthesia twice. All paresthesias were transient. Following a paresthesia, CSF was observed in the needle hub 86.7% (13/15) of the time. Our data suggest that the majority of transient paresthesias occur when the spinal needle enters the subarachnoid space and contacts a spinal nerve root. Therefore, when transient paresthesias occur during spinal needle placement it is appropriate to stop and assess for the presence of CSF in the needle hub, rather than withdraw and redirect the spinal needle away from the side of the paresthesia as some authors have suggested.

First-Pass Contrast-Enhanced MRA for Pretherapeutic Diagnosis of Spinal Epidural Arteriovenous Fistulas with Intradural Venous Reflux.

PubMed

Mathur, S; Symons, S P; Huynh, T J; Muthusami, P; Montanera, W; Bharatha, A

2017-01-01

Spinal epidural AVFs are rare spinal vascular malformations. When there is associated intradural venous reflux, they may mimic the more common spinal dural AVFs. Correct diagnosis and localization before conventional angiography is beneficial to facilitate treatment. We hypothesize that first-pass contrast-enhanced MRA can diagnose and localize spinal epidural AVFs with intradural venous reflux and distinguish them from other spinal AVFs. Forty-two consecutive patients with a clinical and/or radiologic suspicion of spinal AVF underwent MR imaging, first-pass contrast-enhanced MRA, and DSA at a single institute (2000-2015). MR imaging/MRA and DSA studies were reviewed by 2 independent blinded observers. DSA was used as the reference standard. On MRA, all 7 spinal epidural AVFs with intradural venous reflux were correctly diagnosed and localized with no interobserver disagreement. The key diagnostic feature was arterialized filling of an epidural venous pouch with a refluxing radicular vein arising from the arterialized epidural venous system. First-pass contrast-enhanced MRA is a reliable and useful technique for the initial diagnosis and localization of spinal epidural AVFs with intradural venous reflux and can distinguish these lesions from other spinal AVFs. © 2017 by American Journal of Neuroradiology.

Changes in lumbosacral spinal nerve roots on diffusion tensor imaging in spinal stenosis.

PubMed

Hou, Zhong-Jun; Huang, Yong; Fan, Zi-Wen; Li, Xin-Chun; Cao, Bing-Yi

2015-11-01

Lumbosacral degenerative disc disease is a common cause of lower back and leg pain. Conventional T1-weighted imaging (T1WI) and T2-weighted imaging (T2WI) scans are commonly used to image spinal cord degeneration. However, these modalities are unable to image the entire lumbosacral spinal nerve roots. Thus, in the present study, we assessed the potential of diffusion tensor imaging (DTI) for quantitative assessment of compressed lumbosacral spinal nerve roots. Subjects were 20 young healthy volunteers and 31 patients with lumbosacral stenosis. T2WI showed that the residual dural sac area was less than two-thirds that of the corresponding normal area in patients from L3 to S1 stenosis. On T1WI and T2WI, 74 lumbosacral spinal nerve roots from 31 patients showed compression changes. DTI showed thinning and distortion in 36 lumbosacral spinal nerve roots (49%) and abruption in 17 lumbosacral spinal nerve roots (23%). Moreover, fractional anisotropy values were reduced in the lumbosacral spinal nerve roots of patients with lumbosacral stenosis. These findings suggest that DTI can objectively and quantitatively evaluate the severity of lumbosacral spinal nerve root compression.

Clinical Guideline for Treatment of Symptomatic Thoracic Spinal Stenosis.

PubMed

Chen, Zhong-qiang; Sun, Chui-guo

2015-08-01

Thoracic spinal stenosis is a relatively common disorder causing paraplegia in the population of China. Until nowadays, the clinical management of thoracic spinal stenosis is still demanding and challenging with lots of questions remaining to be answered. A clinical guideline for the treatment of symptomatic thoracic spinal stenosis has been created by reaching the consensus of Chinese specialists using the best available evidence as a tool to aid practitioners involved with the care of this disease. In this guideline, many fundamental questions about thoracic spinal stenosis which were controversial have been explained clearly, including the definition of thoracic spinal stenosis, the standard procedure for diagnosing symptomatic thoracic spinal stenosis, indications for surgery, and so on. According to the consensus on the definition of thoracic spinal stenosis, the soft herniation of thoracic discs has been excluded from the pathological factors causing thoracic spinal stenosis. The procedure for diagnosing thoracic spinal stenosis has been quite mature, while the principles for selecting operative procedures remain to be improved. This guideline will be updated on a timely schedule and adhering to its recommendations should not be mandatory because it does not have the force of law. © 2015 Chinese Orthopaedic Association and Wiley Publishing Asia Pty Ltd.

Neural control of locomotion and training-induced plasticity after spinal and cerebral lesions.

PubMed

Knikou, Maria

2010-10-01

Standing and walking require a plethora of sensorimotor interactions that occur throughout the nervous system. Sensory afferent feedback plays a crucial role in the rhythmical muscle activation pattern, as it affects through spinal reflex circuits the spinal neuronal networks responsible for inducing and maintaining rhythmicity, drives short-term and long-term re-organization of the brain and spinal cord circuits, and contributes to recovery of walking after locomotor training. Therefore, spinal circuits integrating sensory signals are adjustable networks with learning capabilities. In this review, I will synthesize the mechanisms underlying phase-dependent modulation of spinal reflexes in healthy humans as well as those with spinal or cerebral lesions along with findings on afferent regulation of spinal reflexes and central pattern generator in reduced animal preparations. Recovery of walking after locomotor training has been documented in numerous studies but the re-organization of spinal interneuronal and cortical circuits need to be further explored at cellular and physiological levels. For maximizing sensorimotor recovery in people with spinal or cerebral lesions, a multidisciplinary approach (rehabilitation, pharmacology, and electrical stimulation) delivered during various sensorimotor constraints is needed. Copyright 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Radiographic and MRI characteristics of lumbar disseminated idiopathic spinal hyperostosis and spondylosis deformans in dogs.

PubMed

Togni, A; Kranenburg, H J C; Morgan, J P; Steffen, F

2014-07-01

To evaluate clinical signs, describe lesions and differences in the magnetic resonance imaging appearance of spinal new bone formations classified as disseminated idiopathic spinal hyperostosis and/or spondylosis deformans on radiographs and compare degeneration status of the intervertebral discs using the Pfirrmann scale. Retrospective analysis of 18 dogs presented with spinal disorders using information from radiographic and magnetic resonance imaging examinations. All dogs were found to be affected with both disseminated idiopathic spinal hyperostosis and spondylosis deformans. Neurological signs due to foraminal stenosis associated with disseminated idiopathic spinal hyperostosis were found in two dogs. Spondylosis deformans was associated with foraminal stenosis and/or disc protrusion in 15 cases. The Pfirrmann score on magnetic resonance imaging was significantly higher in spondylosis deformans compared with disseminated idiopathic spinal hyperostosis and signal intensity of new bone due to disseminated idiopathic spinal hyperostosis was significantly higher compared to spondylosis deformans. Differences between disseminated idiopathic spinal hyperostosis and spondylosis deformans found on magnetic resonance imaging contribute to an increased differentiation between the two entities. Clinically relevant lesions in association with disseminated idiopathic spinal hyperostosis were rare compared to those seen with spondylosis deformans. © 2014 British Small Animal Veterinary Association.

Involvement of the Spinal Cord in Mitochondrial Disorders.

PubMed

Finsterer, Josef; Zarrouk-Mahjoub, Sinda

2018-01-01

This review aims at summarising and discussing the current status concerning the clinical presentation, pathogenesis, diagnosis, and treatment of spinal cord affection in mitochondrial disorders (MIDs). A literature search using the database Pubmed was carried out by application of appropriate search terms and their combinations. Involvement of the spinal cord in MIDs is more frequent than anticipated. It occurs in specific and non-specific MIDs. Among the specific MIDs it has been most frequently described in LBSL, LS, MERRF, KSS, IOSCA, MIRAS, and PCH and only rarely in MELAS, CPEO, and LHON. Clinically, spinal cord involvement manifests as monoparesis, paraparesis, quadruparesis, sensory disturbances, hypotonia, spasticity, urinary or defecation dysfunction, spinal column deformities, or as transverse syndrome. Diagnosing spinal cord involvement in MIDs requires a thoroughly taken history, clinical exam, and imaging studies. Additionally, transcranial magnetic stimulation, somato-sensory-evoked potentials, and cerebro-spinal fluid can be supportive. Treatment is generally not at variance compared to the underlying MID but occasionally surgical stabilisation of the spinal column may be necessary. It is concluded that spinal cord involvement in MIDs is more frequent than anticipated but may be missed if cerebral manifestations prevail. Spinal cord involvement in MIDs may strongly determine the mobility of these patients.

Imaging: what can it tell us about parkinsonian gait?

PubMed Central

Bohnen, Nicolaas I.; Jahn, Klaus

2013-01-01

Functional neuroimaging has provided new tools to study cerebral gait control in Parkinson disease (PD). First, imaging of blood flow functions has identified a supraspinal locomotor network that includes the (frontal) cortex, basal ganglia, brainstem tegmentum and the cerebellum. These studies emphasize also the cognitive and attentional dependency of gait in PD. Furthermore, gait in PD and related syndromes like progressive supranuclear palsy may be associated with dysfunction of the indirect, modulatory prefrontal–subthalamic–pedunculopontine loop of locomotor control. The direct, stereotyped locomotor loop from the primary motor cortex to the spinal cord with rhythmic cerebellar input appears preserved and may contribute to the unflexible gait pattern in parkinsonian gait. Second, neurotransmitter and proteinopathy imaging studies are beginning to unravel novel mechanisms of parkinsonian gait and postural disturbances. Dopamine displacement imaging studies have shown evidence for a mesofrontal dopaminergic shift from a depleted striatum in parkinsonian gait. This may place additional burden on other brain systems mediating attention functions to perform previously automatic motor tasks. For example, our preliminary cholinergic imaging studies suggest significant slowing of gait speed when additional forebrain cholinergic denervation occurs in PD. Cholinergic denervation of the pedunculopontine nucleus and its thalamic projections have been associated with falls and impaired postural control. Deposition of β-amyloid may represent another non-dopaminergic correlate of gait disturbance in PD. These findings illustrate the emergence of dopamine non-responsive gait problems to reflect the transition from a predominantly hypodopaminergic disorder to a multisystem neurodegenerative disorder involving non-dopaminergic locomotor network structures and pathologies. PMID:24132837

A scoping review of biopsychosocial risk factors and co-morbidities for common spinal disorders.

PubMed

Green, Bart N; Johnson, Claire D; Haldeman, Scott; Griffith, Erin; Clay, Michael B; Kane, Edward J; Castellote, Juan M; Rajasekaran, Shanmuganathan; Smuck, Matthew; Hurwitz, Eric L; Randhawa, Kristi; Yu, Hainan; Nordin, Margareta

2018-01-01

The purpose of this review was to identify risk factors, prognostic factors, and comorbidities associated with common spinal disorders. A scoping review of the literature of common spinal disorders was performed through September 2016. To identify search terms, we developed 3 terminology groups for case definitions: 1) spinal pain of unknown origin, 2) spinal syndromes, and 3) spinal pathology. We used a comprehensive strategy to search PubMed for meta-analyses and systematic reviews of case-control studies, cohort studies, and randomized controlled trials for risk and prognostic factors and cross-sectional studies describing associations and comorbidities. Of 3,453 candidate papers, 145 met study criteria and were included in this review. Risk factors were reported for group 1: non-specific low back pain (smoking, overweight/obesity, negative recovery expectations), non-specific neck pain (high job demands, monotonous work); group 2: degenerative spinal disease (workers' compensation claim, degenerative scoliosis), and group 3: spinal tuberculosis (age, imprisonment, previous history of tuberculosis), spinal cord injury (age, accidental injury), vertebral fracture from osteoporosis (type 1 diabetes, certain medications, smoking), and neural tube defects (folic acid deficit, anti-convulsant medications, chlorine, influenza, maternal obesity). A range of comorbidities was identified for spinal disorders. Many associated factors for common spinal disorders identified in this study are modifiable. The most common spinal disorders are co-morbid with general health conditions, but there is a lack of clarity in the literature differentiating which conditions are merely comorbid versus ones that are risk factors. Modifiable risk factors present opportunities for policy, research, and public health prevention efforts on both the individual patient and community levels. Further research into prevention interventions for spinal disorders is needed to address this gap in the literature.

A scoping review of biopsychosocial risk factors and co-morbidities for common spinal disorders

PubMed Central

Smuck, Matthew; Hurwitz, Eric L.; Randhawa, Kristi; Yu, Hainan; Nordin, Margareta

2018-01-01

Objective The purpose of this review was to identify risk factors, prognostic factors, and comorbidities associated with common spinal disorders. Methods A scoping review of the literature of common spinal disorders was performed through September 2016. To identify search terms, we developed 3 terminology groups for case definitions: 1) spinal pain of unknown origin, 2) spinal syndromes, and 3) spinal pathology. We used a comprehensive strategy to search PubMed for meta-analyses and systematic reviews of case-control studies, cohort studies, and randomized controlled trials for risk and prognostic factors and cross-sectional studies describing associations and comorbidities. Results Of 3,453 candidate papers, 145 met study criteria and were included in this review. Risk factors were reported for group 1: non-specific low back pain (smoking, overweight/obesity, negative recovery expectations), non-specific neck pain (high job demands, monotonous work); group 2: degenerative spinal disease (workers’ compensation claim, degenerative scoliosis), and group 3: spinal tuberculosis (age, imprisonment, previous history of tuberculosis), spinal cord injury (age, accidental injury), vertebral fracture from osteoporosis (type 1 diabetes, certain medications, smoking), and neural tube defects (folic acid deficit, anti-convulsant medications, chlorine, influenza, maternal obesity). A range of comorbidities was identified for spinal disorders. Conclusion Many associated factors for common spinal disorders identified in this study are modifiable. The most common spinal disorders are co-morbid with general health conditions, but there is a lack of clarity in the literature differentiating which conditions are merely comorbid versus ones that are risk factors. Modifiable risk factors present opportunities for policy, research, and public health prevention efforts on both the individual patient and community levels. Further research into prevention interventions for spinal disorders is needed to address this gap in the literature. PMID:29856783

A comparison of Espocan and Tuohy needles for the combined spinal-epidural technique for labor analgesia.

PubMed

Browne, Ingrid M; Birnbach, David J; Stein, Deborah J; O'Gorman, David A; Kuroda, Maxine

2005-08-01

When using the needle-through-needle combined spinal-epidural (CSE) technique for labor analgesia, failure to obtain cerebrospinal fluid (CSF), paresthesias, and intrathecal or intravascular migration of the catheter are of concern. Epidural needles with spinal needle apertures, such as the back-hole Espocan (ES) needles, are available and may reduce these risks. We describe the efficacy and adverse events associated with a modified epidural needle (ES) versus a conventional Tuohy needle for CSE. One-hundred parturients requesting labor analgesia (CSE) were randomized into 2 groups: 50-ES 18-gauge modified epidural needle with 27-gauge Pencan atraumatic spinal needle, 50-conventional 18-gauge Tuohy needle with 27-gauge Gertie Marx atraumatic spinal needle. Information on intrathecal or intravascular catheter placement, paresthesia on introduction of spinal needle, failure to obtain CSF through the spinal needle after placement of epidural needle, unintentional dural puncture, and epidural catheter function was obtained. No intrathecal catheter placement occurred in either group. Rates of intravascular catheter placement and unintentional dural puncture were similar between the groups. Significant differences were noted regarding spinal needle-induced paresthesia (14% ES versus 42% Tuohy needles, P = 0.009) and failure to obtain CSF on first attempt (8% ES versus 28% Tuohy needles, P < 0.02). Use of ES needles for CSE significantly reduces paresthesia associated with the insertion of the spinal needle and is associated with more frequent successful spinal needle placement on the first attempt. The use of modified epidural needles with a back hole for combined spinal-epidural technique significantly reduces paresthesia associated with the insertion of the spinal needle and is associated with more frequent successful spinal needle placement on the first attempt.

MicroRNA-21a-5p promotes fibrosis in spinal fibroblasts after mechanical trauma.

PubMed

Wang, Wenzhao; Tang, Shi; Li, Hongfei; Liu, Ronghan; Su, Yanlin; Shen, Lin; Sun, Mingjie; Ning, Bin

2018-06-05

Traumatic spinal cord injury (SCI) causes permanent disability to at least 180,000 people per year worldwide. Early regulation of spinal fibroblast proliferation may inhibit fibrotic scar formation, allowing the creation of a favorable environment for neuronal regeneration and thereby enhancing recovery from traumatic SCIs. In this study, we aimed to identify the role of microRNA-21a-5p (miR-21a-5p) in regulating spinal fibroblasts after mechanical trauma and to investigate the dysregulation of miR-21a-5p in the pathological process of spinal SCI. We investigated the differential expression of microRNAs in primary spinal fibroblasts after mechanical trauma and found that the expression of miR-21a-5p was higher in spinal fibroblasts after scratch damage (SD). In addition, mouse spinal fibroblasts were transfected with miR-21a-5p mimics/inhibitor, and the role of miR-21a-5p in spinal fibrogenic activation was analyzed. These experiments demonstrated that miR-21a-5p overexpression promoted fibrogenic activity in spinal fibroblasts after mechanical trauma, as well as enhancing proliferation and attenuating apoptosis in spinal fibroblasts. Finally, the potential role of miR-21a-5p in regulating the Smad signaling pathway was examined. MiR-21a-5p activated the Smad signaling pathway by enhancing Smad2/3 phosphorylation. These results suggest that miR-21a-5p promotes spinal fibrosis after mechanical trauma. Based on these findings, we propose a close relationship between miR-21a-5p and spinal fibrosis, providing a new potential therapeutic target for SCI. Copyright © 2018. Published by Elsevier Inc.

Spinal Endomorphin 2 Antinociception and the Mechanisms That Produce It Are Both Sex- and Stage of Estrus Cycle–Dependent in Rats

PubMed Central

Liu, Nai-Jiang; Gintzler, Alan R.

2014-01-01

Endomorphin 2 (EM2) is the predominant endogenous mu-opioid receptor (MOR) ligand in the spinal cord. Given its endogenous presence, antinociceptive responsiveness to the intrathecal application of EM2 most likely reflects its ability to modulate nociception when released in situ. In order to explore the physiological pliability of sex-dependent differences in spinal MOR-mediated antinociception, we investigated the antinociception produced by intrathecal EM2 in male, proestrus female, and diestrus female rats. Antinociception was reflected by changes in tail flick latency to radiant heat. In females, the spinal EM2 antinociceptive system oscillated between analgesically active and inactive states. During diestrus, when circulating estrogens are low, spinal EM2 antinociceptive responsiveness was minimal. In contrast, during proestrus, when circulating estrogens are high, spinal EM2 antinociception was robust and comparable in magnitude to that manifest by males. Furthermore, in proestrus females, spinal EM2 antinociception required spinal dynorphin and kappaopioid receptor activation, concomitant with MOR activation. This is required for neither spinal EM2 antinociception in males nor the antinociception elicited in proestrus females by spinal sufentanil or [d-Ala2,N-methyl-Phe4,Gly-ol5]-enkephalin, which are prototypic MOR-selective nonpeptide and peptide agonists, respectively. These results reveal that spinal EM2 antinociception and the signaling mechanisms used to produce it fundamentally differ in males and females. Perspective The inability to mount spinal EM2 antinociception during defined stages of the estrus (and presumably menstrual) cycle and impaired transition from spinal EM2 analgesically nonresponsive to responsive physiological states could be causally associated with the well-documented greater severity and frequency of chronic intractable pain syndromes in women vs men. PMID:24084000

Trends of Incidence, Mortality, and Future Projection of Spinal Fractures in Korea Using Nationwide Claims Data.

PubMed

Kim, Tae-Young; Jang, Sunmee; Park, Chan-Mi; Lee, Ahreum; Lee, Young-Kyun; Kim, Ha-Young; Cho, Eun-Hee; Ha, Yong-Chan

2016-05-01

Spinal fractures have been recognized as a major health concern. Our purposes were to evaluate the trends in the incidence and mortality of spinal fractures between 2008 and 2012 and predict the number of spinal fractures that will occur in Korea up to 2025, using nationwide data from the National Health Insurance Service (NHIS). A nationwide data set was evaluated to identify all new visits to medical institutes for spinal fractures in men and women aged 50 years or older between 2008 and 2012. The incidence, mortality rates and estimates of the number of spinal fractures were calculated using Poisson regression. The number of spinal fractures increased over the time span studied. Men and women experienced 14,808 and 55,164 vertebral fractures in 2008 and 22,739 and 79,903 in 2012, respectively. This reflects an increase in the incidence of spinal fractures for both genders (men, 245.3/100,000 in 2008 and 312.5/100,000 in 2012; women, 780.6/100,000 in 2008 and 953.4/100,000 in 2012). The cumulative mortality rate in the first year after spinal fractures decreased from 8.51% (5,955/69,972) in 2008 to 7.0% (7,187/102,642) in 2012. The overall standardized mortality ratio (SMR) of spinal fractures at 1 year post-fracture was higher in men (7.76, 95% CI: 7.63-7.89) than in women (4.70, 95% CI: 4.63-4.76). The total number of spinal fractures is expected to reach 157,706 in 2025. The incidence of spinal fractures increased in Korea in the last 5 years, and the socioeconomic burden of spinal fractures will continue to increase in the near future.

Altered spinal arachidonic acid turnover after peripheral nerve injury regulates regional glutamate concentration and neuropathic pain behaviors in rats.

PubMed

Sung, Backil; Wang, Shuxing; Zhou, Bei; Lim, Grewo; Yang, Liling; Zeng, Qing; Lim, Jeong-Ae; Wang, Jing Dong; Kang, Jing X; Mao, Jianren

2007-09-01

Spinal glutamate transporters (GT) have been implicated in the mechanisms of neuropathic pain; however, how spinal GT uptake activity is regulated remains unclear. Here we show that alteration of spinal arachidonic acid (AA) turnover after peripheral nerve injury regulated regional GT uptake activity and glutamate homeostasis. Chronic constriction nerve injury (CCI) in rats significantly reduced spinal GT uptake activity ((3)H-glutamate uptake) with an associated increase in extracellular AA and glutamate concentration from spinal microdialysates on postoperative day 8. AACOCF3 (a cytosolic phospholipase A2 inhibitor, 30mug) given intrathecally twice a day for postoperative day 1-7 reversed this CCI-induced spinal AA production, prevented the reduced spinal GT uptake activity and increased extracellular glutamate concentration. Conversely, alteration of spinal AA metabolism by diclofenac (a cyclooxygenase 1/2 inhibitor, 200mug) further reduced spinal GT uptake activity and increased extracellular glutamate concentration in CCI rats. GT uptake activity was also attenuated when AA (10 or 100nM) was directly added into spinal samples of naïve rats in an in vitro(3)H-glutamate uptake assay, indicating a direct inhibitory effect of AA on GT uptake activity. Consistent with these findings, AACOCF3 reduced the development of both thermal hyperalgesia and mechanical allodynia, whereas diclofenac exacerbated thermal hyperalgesia, in CCI rats. Thus, spinal AA turnover may serve as a regulator in CCI-induced changes in regional GT uptake activity, glutamate homeostasis, and neuropathic pain behaviors. These data suggest that regulating spinal AA turnover may be a useful approach to improving the clinical management of neuropathic pain.

Optical monitoring of spinal cord hemodynamics, a feasibility study

NASA Astrophysics Data System (ADS)

Shadgan, Babak; Kwon, Brian K.; Streijger, Femke; Manouchehri, Neda; So, Kitty; Shortt, Katelyn; Cripton, Peter A.; Macnab, Andrew

2017-02-01

Background: After an acute traumatic spinal cord injury (SCI), the spinal cord is subjected to ischemia, hypoxia, and increased hydrostatic pressure which exacerbate further secondary damage and neuronal deficit. The purpose of this pilot study was to explore the use of near infrared spectroscopy (NIRS) for non-invasive and real-time monitoring of these changes within the injured spinal cord in an animal model. NIRS is a non-invasive optical technique that utilizes light in the near infrared spectrum to monitor changes in the concentration of tissue chromophores from which alterations in tissues oxygenation and perfusion can be inferred in real time. Methods: A custom-made miniaturized NIRS sensor was developed to monitor spinal cord hemodynamics and oxygenation noninvasively and in real time simultaneously with invasive, intraparenchymal monitoring in a pig model of SCI. The spinal cord around the T10 injury site was instrumented with intraparenchymal probes inserted directly into the spinal cord to measure oxygen pressure, blood flow, and hydrostatic pressure, and the same region of the spinal cord was monitored with the custom-designed extradural NIRS probe. We investigated how well the extradural NIRS probe detected intraparenchymal changes adjacent to the injury site after alterations in systemic blood pressure, global hypoxia, and traumatic injury generated by a weight-drop contusion. Results: The NIRS sensor successfully identified periods of systemic hypoxia, re-ventilation and changes in spinal cord perfusion and oxygenation during alterations of mean arterial pressure and following spinal cord injury. Conclusion: This pilot study indicates that extradural NIRS monitoring of the spinal cord is feasible as a non-invasive optical method to identify changes in spinal cord hemodynamics and oxygenation in real time. Further development of this technique would allow clinicians to monitor real-time physiologic changes within the injured spinal cord during the acute post-injury period.

Spinal stenosis

MedlinePlus

... stenosis; LBP - stenosis Patient Instructions Spine surgery - discharge Images Sciatic nerve Spinal stenosis Spinal stenosis References Försth P, Ólafsson G, Carlsson T, et al. A randomized, controlled trial of fusion surgery for lumbar spinal stenosis. N Engl J ...

Effects of spinal cord injury-induced changes in muscle activation on foot drag in a computational rat ankle model

PubMed Central

Hillen, Brian K.; Jindrich, Devin L.; Abbas, James J.; Yamaguchi, Gary T.

2015-01-01

Spinal cord injury (SCI) can lead to changes in muscle activation patterns and atrophy of affected muscles. Moderate levels of SCI are typically associated with foot drag during the swing phase of locomotion. Foot drag is often used to assess locomotor recovery, but the causes remain unclear. We hypothesized that foot drag results from inappropriate muscle coordination preventing flexion at the stance-to-swing transition. To test this hypothesis and to assess the relative contributions of neural and muscular changes on foot drag, we developed a two-dimensional, one degree of freedom ankle musculoskeletal model with gastrocnemius and tibialis anterior muscles. Anatomical data collected from sham-injured and incomplete SCI (iSCI) female Long-Evans rats as well as physiological data from the literature were used to implement an open-loop muscle dynamics model. Muscle insertion point motion was calculated with imposed ankle trajectories from kinematic analysis of treadmill walking in sham-injured and iSCI animals. Relative gastrocnemius deactivation and tibialis anterior activation onset times were varied within physiologically relevant ranges based on simplified locomotor electromyogram profiles. No-atrophy and moderate muscle atrophy as well as normal and injured muscle activation profiles were also simulated. Positive moments coinciding with the transition from stance to swing phase were defined as foot swing and negative moments as foot drag. Whereas decreases in activation delay caused by delayed gastrocnemius deactivation promote foot drag, all other changes associated with iSCI facilitate foot swing. Our results suggest that even small changes in the ability to precisely deactivate the gastrocnemius could result in foot drag after iSCI. PMID:25673734

Mesoporous silica nanoparticles for treating spinal cord injury

NASA Astrophysics Data System (ADS)

White-Schenk, Désirée.; Shi, Riyi; Leary, James F.

2013-02-01

An estimated 12,000 new cases of spinal cord injury (SCI) occur every year in the United States. A small oxidative molecule responsible for secondary injury, acrolein, is an important target in SCI. Acrolein attacks essential proteins and lipids, creating a feed-forward loop of oxidative stress in both the primary injury area and the surrounding areas. A small molecule used and FDA-approved for hypertension, hydralazine, has been found to "scavenge" acrolein after injury, but its delivery and short half-life, as well as its hypertension effects, hinder its application for SCI. Nanomedical systems broaden the range of therapeutic availability and efficacy over conventional medicine. They allow for targeted delivery of therapeutic molecules to tissues of interest, reducing side effects of untargeted therapies in unwanted areas. Nanoparticles made from silica form porous networks that can carry therapeutic molecules throughout the body. To attenuate the acrolein cascade and improve therapeutic availability, we have used a one-step, modified Stober method to synthesize two types of silica nanoparticles. Both particles are "stealth-coated" with poly(ethylene) glycol (PEG) (to minimize interactions with the immune system and to increase circulation time), which is also a therapeutic agent for SCI by facilitating membrane repair. One nanoparticle type contains an amine-terminal PEG (SiNP-mPEG-Am) and the other possesses a terminal hydrazide group (SiNP-mPEG-Hz). The former allows for exploration of hydralazine delivery, loading, and controlled release. The latter group has the ability to react with acrolein, allowing the nanoparticle to scavenge directly. The nanoparticles have been characterized and are being explored using neuronal PC-12 cells in vitro, demonstrating the potential of novel silica nanoparticles for use in attenuating secondary injury after SCI.

Innovative Technique for the Placement of the Drainage Tube for Microendoscopic Spinal Decompression.

PubMed

Mizuno, Kentaro; Mikami, Yasuo; Hase, Hitoshi; Ikeda, Takumi; Nagae, Masateru; Tonomura, Hitoshi; Shirai, Toshiharu; Fujiwara, Hiroyoshi; Kubo, Toshikazu

2017-02-01

A technical note and retrospective study. The objectives were to describe a new method of drainage tube placement during microendoscopic spinal decompression, and compare the positioning and fluid discharge obtained with this method and the conventional method. To prevent postoperative epidural hematoma after microendoscopic decompression, a drainage tube must be placed in a suitable location. However, the narrow operative field makes precise control of the position of the tube technically difficult. We developed a method to reliably place the tube in the desired location. We use a Deschamps aneurysm needle with a slightly curved tip, which we call a drain passer. With the microendoscope in position, the drain passer, with a silk thread passed through the eye at the needle tip, is inserted percutaneously into the endoscopic field of view. The drainage tube is passed through the loop of silk thread protruding from the inside of the tubular retractor, and the thread is pulled to the outside, guiding the end of the drainage tube into the wound. This method was used in 23 cases at 44 intervertebral levels (drain passer group), and the conventional method in 20 cases at 32 intervertebral levels (conventional group). Postoperative plain radiographs were taken, and the amount of fluid discharge at postoperative hour 24 was measured. Drainage tube positioning was favorable at 43 intervertebral levels (97.7%) in the drain passer group and 26 intervertebral levels (81.3%) in the conventional group. Mean fluid discharge was 58.4±32.2 g in the drain passer group and 38.4±23.0 g in the conventional group. Positioning was significantly better and fluid discharge was significantly greater in the drain passer group. The results indicate that this method is a useful drainage tube placement technique for preventing postoperative epidural hematoma.

Effects of spinal cord injury-induced changes in muscle activation on foot drag in a computational rat ankle model.

PubMed

Hillen, Brian K; Jindrich, Devin L; Abbas, James J; Yamaguchi, Gary T; Jung, Ranu

2015-04-01

Spinal cord injury (SCI) can lead to changes in muscle activation patterns and atrophy of affected muscles. Moderate levels of SCI are typically associated with foot drag during the swing phase of locomotion. Foot drag is often used to assess locomotor recovery, but the causes remain unclear. We hypothesized that foot drag results from inappropriate muscle coordination preventing flexion at the stance-to-swing transition. To test this hypothesis and to assess the relative contributions of neural and muscular changes on foot drag, we developed a two-dimensional, one degree of freedom ankle musculoskeletal model with gastrocnemius and tibialis anterior muscles. Anatomical data collected from sham-injured and incomplete SCI (iSCI) female Long-Evans rats as well as physiological data from the literature were used to implement an open-loop muscle dynamics model. Muscle insertion point motion was calculated with imposed ankle trajectories from kinematic analysis of treadmill walking in sham-injured and iSCI animals. Relative gastrocnemius deactivation and tibialis anterior activation onset times were varied within physiologically relevant ranges based on simplified locomotor electromyogram profiles. No-atrophy and moderate muscle atrophy as well as normal and injured muscle activation profiles were also simulated. Positive moments coinciding with the transition from stance to swing phase were defined as foot swing and negative moments as foot drag. Whereas decreases in activation delay caused by delayed gastrocnemius deactivation promote foot drag, all other changes associated with iSCI facilitate foot swing. Our results suggest that even small changes in the ability to precisely deactivate the gastrocnemius could result in foot drag after iSCI. Copyright © 2015 the American Physiological Society.

Does the intrathecal propofol have a neuroprotective effect on spinal cord ischemia?

PubMed Central

Sahin, Murat; Gullu, Huriye; Peker, Kemal; Sayar, Ilyas; Binici, Orhan; Yildiz, Huseyin

2015-01-01

The neuroprotective effects of propofol have been confirmed. However, it remains unclear whether intrathecal administration of propofol exhibits neuroprotective effects on spinal cord ischemia. At 1 hour prior to spinal cord ischemia, propofol (100 and 300 µg) was intrathecally administered in rats with spinal cord ischemia. Propofol pre-treatment greatly improved rat pathological changes and neurological function deficits at 24 hours after spinal cord ischemia. These results suggest that intrathecal administration of propofol exhibits neuroprotective effects on spinal cord structural and functional damage caused by ischemia. PMID:26807119

Does the intrathecal propofol have a neuroprotective effect on spinal cord ischemia?

PubMed

Sahin, Murat; Gullu, Huriye; Peker, Kemal; Sayar, Ilyas; Binici, Orhan; Yildiz, Huseyin

2015-11-01

The neuroprotective effects of propofol have been confirmed. However, it remains unclear whether intrathecal administration of propofol exhibits neuroprotective effects on spinal cord ischemia. At 1 hour prior to spinal cord ischemia, propofol (100 and 300 µg) was intrathecally administered in rats with spinal cord ischemia. Propofol pre-treatment greatly improved rat pathological changes and neurological function deficits at 24 hours after spinal cord ischemia. These results suggest that intrathecal administration of propofol exhibits neuroprotective effects on spinal cord structural and functional damage caused by ischemia.

Comparison of cutting and pencil-point spinal needle in spinal anesthesia regarding postdural puncture headache

PubMed Central

Xu, Hong; Liu, Yang; Song, WenYe; Kan, ShunLi; Liu, FeiFei; Zhang, Di; Ning, GuangZhi; Feng, ShiQing

2017-01-01

Abstract Background: Postdural puncture headache (PDPH), mainly resulting from the loss of cerebral spinal fluid (CSF), is a well-known iatrogenic complication of spinal anesthesia and diagnostic lumbar puncture. Spinal needles have been modified to minimize complications. Modifiable risk factors of PDPH mainly included needle size and needle shape. However, whether the incidence of PDPH is significantly different between cutting-point and pencil-point needles was controversial. Then we did a meta-analysis to assess the incidence of PDPH of cutting spinal needle and pencil-point spinal needle. Methods: We included all randomly designed trials, assessing the clinical outcomes in patients given elective spinal anesthesia or diagnostic lumbar puncture with either cutting or pencil-point spinal needle as eligible studies. All selected studies and the risk of bias of them were assessed by 2 investigators. Clinical outcomes including success rates, frequency of PDPH, reported severe PDPH, and the use of epidural blood patch (EBP) were recorded as primary results. Results were evaluated using risk ratio (RR) with 95% confidence interval (CI) for dichotomous variables. Rev Man software (version 5.3) was used to analyze all appropriate data. Results: Twenty-five randomized controlled trials (RCTs) were included in our study. The analysis result revealed that pencil-point spinal needle would result in lower rate of PDPH (RR 2.50; 95% CI [1.96, 3.19]; P < 0.00001) and severe PDPH (RR 3.27; 95% CI [2.15, 4.96]; P < 0.00001). Furthermore, EBP was less used in pencil-point spine needle group (RR 3.69; 95% CI [1.96, 6.95]; P < 0.0001). Conclusions: Current evidences suggest that pencil-point spinal needle was significantly superior compared with cutting spinal needle regarding the frequency of PDPH, PDPH severity, and the use of EBP. In view of this, we recommend the use of pencil-point spinal needle in spinal anesthesia and lumbar puncture. PMID:28383416

The increased prevalence of cervical spondylosis in patients with adult thoracolumbar spinal deformity.

PubMed

Schairer, William W; Carrer, Alexandra; Lu, Michael; Hu, Serena S

2014-12-01

Retrospective cohort study. To assess the concomitance of cervical spondylosis and thoracolumbar spinal deformity. Patients with degenerative cervical spine disease have higher rates of degeneration in the lumbar spine. In addition, degenerative cervical spine changes have been observed in adult patients with thoracolumbar spinal deformities. However, to the best of our knowledge, there have been no studies quantifying the association between cervical spondylosis and thoracolumbar spinal deformity in adult patients. Patients seen by a spine surgeon or spine specialist at a single institution were assessed for cervical spondylosis and/or thoracolumbar spinal deformity using an administrative claims database. Spinal radiographic utilization and surgical intervention were used to infer severity of spinal disease. The relative prevalence of each spinal diagnosis was assessed in patients with and without the other diagnosis. A total of 47,560 patients were included in this study. Cervical spondylosis occurred in 13.1% overall, but was found in 31.0% of patients with thoracolumbar spinal deformity (OR=3.27, P<0.0001). Similarly, thoracolumbar spinal deformity was found in 10.7% of patients overall, but was increased at 23.5% in patients with cervical spondylosis (OR=3.26, P<0.0001). In addition, increasing severity of disease was associated with an increased likelihood of the other spinal diagnosis. Patients with both diagnoses were more likely to undergo both cervical (OR=3.23, P<0.0001) and thoracolumbar (OR=4.14, P<0.0001) spine fusion. Patients with cervical spondylosis or thoracolumbar spinal deformity had significantly higher rates of the other spinal diagnosis. This correlation was increased with increased severity of disease. Patients with both diagnoses were significantly more likely to have received a spine fusion. Further research is warranted to establish the cause of this correlation. Clinicians should use this information to both screen and counsel patients who present for cervical spondylosis or thoracolumbar spinal deformity.

Spinal immobilisaton in pre-hospital and emergency care: A systematic review of the literature.

PubMed

Hood, Natalie; Considine, Julie

2015-08-01

Spinal immobilisation has been a mainstay of trauma care for decades and is based on the premise that immobilisation will prevent further neurological compromise in patients with a spinal column injury. The aim of this systematic review was to examine the evidence related to spinal immobilisation in pre-hospital and emergency care settings. In February 2015, we performed a systematic literature review of English language publications from 1966 to January 2015 indexed in MEDLINE and Cochrane library using the following search terms: 'spinal injuries' OR 'spinal cord injuries' AND 'emergency treatment' OR 'emergency care' OR 'first aid' AND immobilisation. EMBASE was searched for keywords 'spinal injury OR 'spinal cord injury' OR 'spine fracture AND 'emergency care' OR 'prehospital care'. There were 47 studies meeting inclusion criteria for further review. Ten studies were case series (level of evidence IV) and there were 37 studies from which data were extrapolated from healthy volunteers, cadavers or multiple trauma patients. There were 15 studies that were supportive, 13 studies that were neutral, and 19 studies opposing spinal immobilisation. There are no published high-level studies that assess the efficacy of spinal immobilisation in pre-hospital and emergency care settings. Almost all of the current evidence is related to spinal immobilisation is extrapolated data, mostly from healthy volunteers. Copyright © 2015 College of Emergency Nursing Australasia Ltd. Published by Elsevier Ltd. All rights reserved.

Spinal Cord Infarction in Clinical Neurology: A Review of Characteristics and Long-Term Prognosis in Comparison to Cerebral Infarction.

PubMed

Romi, Fredrik; Naess, Halvor

2016-01-01

Spinal cord stroke is rare accounting for 0.3-1% of all strokes and is classified into upper (cervical) and lower (thoracolumbar) strokes. Patients present with severe deficits but later often show good functional improvement. On admission, younger age, male gender, hypertension, diabetes mellitus and elevated blood glucose indicate more severe spinal cord strokes. Treatment of these risk factors is essential in the acute phase. Biphasic spinal cord strokes are seen in one-fifth of the patients. These present with acute or transient sensory spinal cord deficits often preceded by radiating pain between the shoulders, and should be considered and treated as imminent spinal cord strokes. Spinal cord infarction patients are younger and more often women compared to cerebral infarction patients. Traditional cerebrovascular risk factors are less relevant in spinal cord infarction. Spinal cord infarction patients are more likely to be discharged home and show better improvement after initial treatment compared to cerebral infarction patients. On long-term follow-up, spinal cord infarction patients have lower mortality and higher emotional well-being scores than cerebral infarction patients. Despite more chronic pain, the frequency of re-employment is higher among spinal cord infarction patients compared to cerebral infarction patients who are more often afflicted with cognitive function deficits. © 2016 S. Karger AG, Basel.

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

Huang, Tianyu; Xu, Hongyi; Chen, Wei

Fiber-reinforced polymer composites are strong candidates for structural materials to replace steel and light alloys in lightweight vehicle design because of their low density and relatively high strength. In the integrated computational materials engineering (ICME) development of carbon fiber composites, microstructure reconstruction algorithms are needed to generate material microstructure representative volume element (RVE) based on the material processing information. The microstructure RVE reconstruction enables the material property prediction by finite element analysis (FEA)This paper presents an algorithm to reconstruct the microstructure of a chopped carbon fiber/epoxy laminate material system produced by compression molding, normally known as sheet molding compounds (SMC).more » The algorithm takes the result from material’s manufacturing process as inputs, such as the orientation tensor of fibers, the chopped fiber sheet geometry, and the fiber volume fraction. The chopped fiber sheets are treated as deformable rectangle chips and a random packing algorithm is developed to pack these chips into a square plate. The RVE is built in a layer-by-layer fashion until the desired number of lamina is reached, then a fine tuning process is applied to finalize the reconstruction. Compared to the previous methods, this new approach has the ability to model bended fibers by allowing limited amount of overlaps of rectangle chips. Furthermore, the method does not need SMC microstructure images, for which the image-based characterization techniques have not been mature enough, as inputs. Case studies are performed and the results show that the statistics of the reconstructed microstructures generated by the algorithm matches well with the target input parameters from processing.« less

Flexible, task-dependent use of sensory feedback to control hand movements

PubMed Central

Knill, David C.; Bondada, Amulya; Chhabra, Manu

2011-01-01

We tested whether changing accuracy demands for simple pointing movements leads humans to adjust the feedback control laws that map sensory signals from the moving hand to motor commands. Subjects made repeated pointing movements in a virtual environment to touch a button whose shape varied randomly from trial-to-trial – between squares, rectangles oriented perpendicular to the movement path and rectangles oriented parallel to the movement path. Subjects performed the task on a horizontal table, but saw the target configuration and a virtual rendering of their pointing finger through a mirror mounted between a monitor and the table. On a one-third of trials, the position of the virtual finger was perturbed by ±1 cm either in the movement direction or perpendicular to the movement direction when the finger passed behind an occluder. Subjects corrected quickly for the perturbations despite not consciously noticing them; however, they corrected almost twice as much for perturbations aligned with the narrow dimension of a target than for perturbations aligned with the long dimension. These changes in apparent feedback gain appeared in the kinematic trajectories soon after the time of the perturbations, indicating that they reflect differences in the feedback control law used throughout the duration of movements. The results indicate that the brain adjusts its feedback control law for individual movements “on-demand” to fit task demands. Simulations of optimal control laws for a two-joint arm show that accuracy demands alone, coupled with signal dependent noise lead to qualitatively the same behavior. PMID:21273407

Diaphragm motion quantification in megavoltage cone-beam CT projection images.

PubMed

Chen, Mingqing; Siochi, R Alfredo

2010-05-01

To quantify diaphragm motion in megavoltage (MV) cone-beam computed tomography (CBCT) projections. User identified ipsilateral hemidiaphragm apex (IHDA) positions in two full exhale and inhale frames were used to create bounding rectangles in all other frames of a CBCT scan. The bounding rectangle was enlarged to create a region of interest (ROI). ROI pixels were associated with a cost function: The product of image gradients and a gradient direction matching function for an ideal hemidiaphragm determined from 40 training sets. A dynamic Hough transform (DHT) models a hemidiaphragm as a contour made of two parabola segments with a common vertex (the IHDA). The images within the ROIs are transformed into Hough space where a contour's Hough value is the sum of the cost function over all contour pixels. Dynamic programming finds the optimal trajectory of the common vertex in Hough space subject to motion constraints between frames, and an active contour model further refines the result. Interpolated ray tracing converts the positions to room coordinates. Root-mean-square (RMS) distances between these positions and those resulting from an expert's identification of the IHDA were determined for 21 Siemens MV CBCT scans. Computation time on a 2.66 GHz CPU was 30 s. The average craniocaudal RMS error was 1.38 +/- 0.67 mm. While much larger errors occurred in a few near-sagittal frames on one patient's scans, adjustments to algorithm constraints corrected them. The DHT based algorithm can compute IHDA trajectories immediately prior to radiation therapy on a daily basis using localization MVCBCT projection data. This has potential for calibrating external motion surrogates against diaphragm motion.

Analyses and Comparison of Solar Air Heater with Various Rib Roughness using Computational Fluid Dynamics (CFD)

NASA Astrophysics Data System (ADS)

Kumar, K. Ravi; Cheepu, Muralimohan; Srinivas, B.; Venkateswarlu, D.; Pramod Kumar, G.; Shiva, Apireddi

2018-03-01

In solar air heater, artificial roughness on absorber plate become prominent technique to improving heat transfer rate of air flowing passage as a result of laminar sublayer. The selection of rib geometries plays important role on friction characteristics and heat transfer rate. Many researchers studying the roughness shapes over the years to investigate the effect of geometries on the performance of friction factor and heat transfer of the solar air heater. The present study made an attempt to develop the different rib shapes utilised for creating artificial rib roughness and its comparison to investigate higher performance of the geometries. The use of computational fluid dynamics software resulted in correlation of friction factor and heat transfer rate. The simulations studies were performed on 2D computational fluid dynamics model and analysed to identify the most effective parameters of relative roughness of the height, width and pitch on major considerations of friction factor and heat transfer. The Reynolds number is varied in a range from 3000 to 20000, in the current study and modelling has conducted on heat transfer and turbulence phenomena by using Reynolds number. The modelling results showed the formation of strong vortex in the main stream flow due to the right angle triangle roughness over the square, rectangle, improved rectangle and equilateral triangle geometries enhanced the heat transfer extension in the solar air heater. The simulation of the turbulence kinetic energy of the geometry suggests the local turbulence kinetic energy has been influenced strongly by the alignments of the right angle triangle.

Figure-ground segregation at contours: a neural mechanism in the visual cortex of the alert monkey.

PubMed

Baumann, R; van der Zwan, R; Peterhans, E

1997-06-01

An important task of vision is the segregation of figure and ground in situations of spatial occlusion. Psychophysical evidence suggests that the depth order at contours is defined early in visual processing. We have analysed this process in the visual cortex of the alert monkey. The animals were trained on a visual fixation task which reinforced foveal viewing. During periods of active visual fixation, we recorded the responses of single neurons in striate and prestriate cortex (areas V1, V2, and V3/V3A). The stimuli mimicked situations of spatial occlusion, usually a uniform light (or dark) rectangle overlaying a grating texture of opposite contrast. The direction of figure and ground at the borders of these rectangles was defined by the direction of the terminating grating lines (occlusion cues). Neuronal responses were analysed with respect to figure-ground direction and contrast polarity at such contours. Striate neurons often failed to respond to such stimuli, or were selective for contrast polarity; others were non-selective. Some neurons preferred a certain combination of figure-ground direction and contrast polarity. These neurons were rare both in striate and prestriate cortex. The majority of neurons signalled figure-ground direction independent of contrast polarity. These neurons were only found in prestriate cortex. We explain these responses in terms of a model which also explains neuronal signals of illusory contours. These results suggest that occlusion cues are used at an early level of processing to segregate figure and ground at contours.

Subarachnoid Hemorrhage due to Spinal Cord Schwannoma Presenting Findings Mimicking Meningitis.

PubMed

Zhang, Hong-Mei; Zhang, Yin-Xi; Zhang, Qing; Song, Shui-Jiang; Liu, Zhi-Rong

2016-08-01

Subarachnoid hemorrhage (SAH) of spinal origin is uncommon in clinical practice, and spinal schwannomas associated with SAH are even more rarely reported. We report an unusual case of spinal SAH mimicking meningitis with normal brain computed tomography (CT)/magnetic resonance imaging (MRI) and negative CT angiography. Cerebrospinal fluid examination results were consistent with the manifestation of SAH. Spinal MRI performed subsequently showed an intradural extramedullary mass. The patient received surgery and was finally diagnosed with spinal cord schwannoma. A retrospective chart review of the patient was performed. We describe a case of SAH due to spinal cord schwannoma. Our case highlights the importance of careful history taking and complete evaluation. We emphasize that spinal causes should always be ruled out in patients with angionegative SAH and that schwannoma should be considered in the differential diagnosis of SAH etiologies even though rare. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

The "beneficial" effects of locomotor training after various types of spinal lesions in cats and rats.

PubMed

Rossignol, Serge; Martinez, Marina; Escalona, Manuel; Kundu, Aritra; Delivet-Mongrain, Hugo; Alluin, Olivier; Gossard, Jean-Pierre

2015-01-01

This chapter reviews a number of experiments on the recovery of locomotion after various types of spinal lesions and locomotor training mainly in cats. We first recall the major evidence on the recovery of hindlimb locomotion in completely spinalized cats at the T13 level and the role played by the spinal locomotor network, also known as the central pattern generator, as well as the beneficial effects of locomotor training on this recovery. Having established that hindlimb locomotion can recover, we raise the issue as to whether spinal plastic changes could also contribute to the recovery after partial spinal lesions such as unilateral hemisections. We found that after such hemisection at T10, cats could recover quadrupedal locomotion and that deficits could be improved by training. We further showed that, after a complete spinalization a few segments below the first hemisection (at T13, i.e., the level of previous studies on spinalization), cats could readily walk with the hindlimbs within hours of completely severing the remaining spinal tracts and not days as is usually the case with only a single complete spinalization. This suggests that neuroplastic changes occurred below the first hemisection so that the cat was already primed to walk after the spinalization subsequent to the hemispinalization 3 weeks before. Of interest is the fact that some characteristic kinematic features in trained or untrained hemispinalized cats could remain after complete spinalization, suggesting that spinal changes induced by training could also be durable. Other studies on reflexes and on the pattern of "fictive" locomotion recorded after curarization corroborate this view. More recent work deals with training cats in more demanding situations such as ladder treadmill (vs. flat treadmill) to evaluate how the locomotor training regimen can influence the spinal cord. Finally, we report our recent studies in rats using compressive lesions or surgical complete spinalization and find that some principles of locomotor recovery in cats also apply to rats when adequate locomotor training is provided. © 2015 Elsevier B.V. All rights reserved.

Spinal cerebrospinal fluid leak as the cause of chronic subdural hematomas in nongeriatric patients.

PubMed

Beck, Jürgen; Gralla, Jan; Fung, Christian; Ulrich, Christian T; Schucht, Philippe; Fichtner, Jens; Andereggen, Lukas; Gosau, Martin; Hattingen, Elke; Gutbrod, Klemens; Z'Graggen, Werner J; Reinert, Michael; Hüsler, Jürg; Ozdoba, Christoph; Raabe, Andreas

2014-12-01

The etiology of chronic subdural hematoma (CSDH) in nongeriatric patients (≤ 60 years old) often remains unclear. The primary objective of this study was to identify spinal CSF leaks in young patients, after formulating the hypothesis that spinal CSF leaks are causally related to CSDH. All consecutive patients 60 years of age or younger who underwent operations for CSDH between September 2009 and April 2011 at Bern University Hospital were included in this prospective cohort study. The patient workup included an extended search for a spinal CSF leak using a systematic algorithm: MRI of the spinal axis with or without intrathecal contrast application, myelography/fluoroscopy, and postmyelography CT. Spinal pathologies were classified according to direct proof of CSF outflow from the intrathecal to the extrathecal space, presence of extrathecal fluid accumulation, presence of spinal meningeal cysts, or no pathological findings. The primary outcome was proof of a CSF leak. Twenty-seven patients, with a mean age of 49.6 ± 9.2 years, underwent operations for CSDH. Hematomas were unilateral in 20 patients and bilateral in 7 patients. In 7 (25.9%) of 27 patients, spinal CSF leakage was proven, in 9 patients (33.3%) spinal meningeal cysts in the cervicothoracic region were found, and 3 patients (11.1%) had spinal cysts in the sacral region. The remaining 8 patients (29.6%) showed no pathological findings. The direct proof of spinal CSF leakage in 25.9% of patients suggests that spinal CSF leaks may be a frequent cause of nongeriatric CSDH.

Lower incidence of postdural puncture headache using whitacre spinal needles after spinal anesthesia: A meta-analysis.

PubMed

Zhang, Di; Chen, LingXiao; Chen, XingYu; Wang, XiaoBo; Li, YuLin; Ning, GuangZhi; Feng, ShiQing

2016-03-01

The aim of this meta-analysis was to evaluate the postdural puncture headache after spinal anesthesia with Whitacre spinal needles compared with Quincke spine needles. We searched several databases, including PubMed, Embase, ISI Web of Knowledge, and Cochrane Central Register of Controlled Trials until October 10th, 2014, for randomized controlled trials that compared spinal anesthesia with Whitacre spinal needles or Quincke spine needles for postdural puncture headache. Two reviewers independently screened the literature, assessed the risk for bias and extracted data. We used RevMan 5.3 software to perform the meta-analysis. Studies were included for the main end points if they addressed the following: frequency of postdural puncture headache, severity of postdural puncture headache as assessed by limitation of activities, and frequency of epidural blood patch. Nine randomized controlled trials were included for meta-analysis. The meta-analysis showed that spinal anesthesia with Whitacre spinal needles achieved lower incidence of postdural puncture headache(RR 0.34; 95% CI [0.22, 0.52]; P < .00001); in addition, the severity of postdural puncture headache was lower in the Whitacre spinal needle group (RR 0.32; 95% CI [0.16, 0.66]; P = .002). Furthermore, the frequency of an epidural blood patch in the Whitacre spinal needle group was lower compared with that in the Quincke spine needle group (RR 0.15; 95% CI [0.04, 0.51]; P = .002). We suggest the Whitacre spinal needles as a superior choice for spinal anesthesia compared with Quincke spine needles. © 2016 American Headache Society.

Smartphone apps for spinal surgery: is technology good or evil?

PubMed

Robertson, Greg A J; Wong, Seng Juong; Brady, Richard R; Subramanian, Ashok S

2016-05-01

The increased utilization of smartphones together with their downloadable applications (apps) provides opportunity for doctors, including spinal surgeons, to integrate such technology into clinical practice. However, the clinical reliability of the medical app sector remains questionable. We reviewed available apps themed specifically towards spinal surgery and related conditions and assessed the level of medical professional involvement in their design and content. The most popular smartphone app stores (Android, Apple, Blackberry, Windows, Samsung, Nokia) were searched for spinal surgery-themed apps, using the disease terms Spinal Surgery, Back Surgery, Spine, Disc Prolapse, Sciatica, Radiculopathy, Spinal Stenosis, Scoliosis, Spinal Fracture and Spondylolisthesis. A total of 78 individual spinal surgery themed apps were identified, of which there were six duplicates (N = 72). According to app store classifications, there were 57 (79 %) medical themed apps, 11 (15 %) health and fitness themed apps, 1 (1 %) business and 3 (4 %) education themed apps. Forty-five (63 %) apps were available for download free of charge. For those that charged access, the prices ranged from £0.62 to £47.99. Only 44 % of spinal surgery apps had customer satisfaction ratings and 56 % had named medical professional involvement in their development or content. This is the first study to specifically address the characteristics of apps related to spinal surgery. We found that nearly half of spinal surgery apps had no named medical professional involvement, raising concerns over app content and evidence base for their use. We recommend increased regulation of spinal surgical apps to improve the accountability of app content.

Dopamine is produced in the rat spinal cord and regulates micturition reflex after spinal cord injury

PubMed Central

Hou, Shaoping; Carson, David M.; Wu, Di; Klaw, Michelle C.; Houlé, John D.; Tom, Veronica J.

2016-01-01

Dopamine (DA) neurons in the mammalian central nervous system are thought to be restricted to the brain. DA-mediated regulation of urinary activity is considered to occur through an interaction between midbrain DA neurons and the pontine micturition center. Here we show that DA is produced in the rat spinal cord and modulates the bladder reflex. We observed numerous tyrosine hydroxylase (TH)+ neurons in the autonomic nuclei and superficial dorsal horn in L6–S3 spinal segments. These neurons are dopamine-β-hydroxylase (DBH)− and some contain detectable dopamine decarboxylase (DDC), suggesting their capacity to produce DA. Interestingly, following a complete thoracic spinal cord injury (SCI) to interrupt supraspinal projections, more TH+ neurons emerged in the lumbosacral spinal cord, coincident with a sustained, low level of DA expression there and a partially recovered micturition reflex. Non-selective blockade of spinal DA receptors reduced bladder activity whereas activation of spinal D2-like receptors increased bladder activity and facilitated voiding. Additionally, depletion of lumbosacral TH+ neurons with 6-hydroxydopamine (6-OHDA) decreased bladder non-voiding contractions and voiding efficiency. Furthermore, injecting the transsynaptic neuronal tracer pseudorabies virus (PRV) into the bladder detrusor labeled TH+ cells in the lumbosacral cord, confirming their involvement in spinal micturition reflex circuits. These results illustrate that DA is synthesized in the rat spinal cord; plasticity of lumbosacral TH+ neurons following SCI may contribute to DA expression and modulate the spinal bladder reflex. Thus, spinally-derived DA and receptors could be a novel therapeutic target to improve micturition recovery after SCI. PMID:26655672

Dopamine is produced in the rat spinal cord and regulates micturition reflex after spinal cord injury.

PubMed

Hou, Shaoping; Carson, David M; Wu, Di; Klaw, Michelle C; Houlé, John D; Tom, Veronica J

2016-11-01

Dopamine (DA) neurons in the mammalian central nervous system are thought to be restricted to the brain. DA-mediated regulation of urinary activity is considered to occur through an interaction between midbrain DA neurons and the pontine micturition center. Here we show that DA is produced in the rat spinal cord and modulates the bladder reflex. We observed numerous tyrosine hydroxylase (TH) + neurons in the autonomic nuclei and superficial dorsal horn in L6-S3 spinal segments. These neurons are dopamine-β-hydroxylase (DBH) - and some contain detectable dopamine decarboxylase (DDC), suggesting their capacity to produce DA. Interestingly, following a complete thoracic spinal cord injury (SCI) to interrupt supraspinal projections, more TH + neurons emerged in the lumbosacral spinal cord, coincident with a sustained, low level of DA expression there and a partially recovered micturition reflex. Non-selective blockade of spinal DA receptors reduced bladder activity whereas activation of spinal D 2 -like receptors increased bladder activity and facilitated voiding. Additionally, depletion of lumbosacral TH + neurons with 6-hydroxydopamine (6-OHDA) decreased bladder non-voiding contractions and voiding efficiency. Furthermore, injecting the transsynaptic neuronal tracer pseudorabies virus (PRV) into the bladder detrusor labeled TH + cells in the lumbosacral cord, confirming their involvement in spinal micturition reflex circuits. These results illustrate that DA is synthesized in the rat spinal cord; plasticity of lumbosacral TH + neurons following SCI may contribute to DA expression and modulate the spinal bladder reflex. Thus, spinally-derived DA and receptors could be a novel therapeutic target to improve micturition recovery after SCI. Published by Elsevier Inc.

Part 1: recognizing neonatal spinal cord injury.

PubMed

Brand, M Colleen

2006-02-01

Neonatal spinal cord injury can occur in utero, as well as after either a difficult delivery or a nontraumatic delivery. Spinal cord injury can also be related to invasive nursery procedures or underlying neonatal pathology. Early clinical signs of spinal cord injury that has occurred in utero or at delivery includes severe respiratory compromise and profound hypotonia. Knowledge of risk factors and awareness of symptoms is required for early recognition and appropriate treatment. This article reviews the embryological development of the spinal column highlighting mechanisms of injury and identifying underlying factors that increase the risk of spinal cord injury in newborns. Signs and symptoms of injury, cervical spine immobilization, and the differential diagnosis are discussed. Nursing implications, general prognosis, and research in spinal cord injury are provided.

Biomechanical properties of the spinal cord: implications for tissue engineering and clinical translation.

PubMed

Bartlett, Richard D; Choi, David; Phillips, James B

2016-10-01

Spinal cord injury is a severely debilitating condition which can leave individuals paralyzed and suffering from autonomic dysfunction. Regenerative medicine may offer a promising solution to this problem. Previous research has focused primarily on exploring the cellular and biological aspects of the spinal cord, yet relatively little remains known about the biomechanical properties of spinal cord tissue. Given that a number of regenerative strategies aim to deliver cells and materials in the form of tissue-engineered therapies, understanding the biomechanical properties of host spinal cord tissue is important. We review the relevant biomechanical properties of spinal cord tissue and provide the baseline knowledge required to apply these important physical concepts to spinal cord tissue engineering.

Central nervous system (image)

MedlinePlus

... receive nerve impulses from the spinal cord and cranial nerves. The spinal cord contains the nerves that carry messages between the brain and the body. Spinal cord injury can occur when there is damage to the cells within the spinal cord or ...

Paired motor cortex and cervical epidural electrical stimulation timed to converge in the spinal cord promotes lasting increases in motor responses

PubMed Central

Mishra, Asht M.; Pal, Ajay; Gupta, Disha

2017-01-01

Key points Pairing motor cortex stimulation and spinal cord epidural stimulation produced large augmentation in motor cortex evoked potentials if they were timed to converge in the spinal cord.The modulation of cortical evoked potentials by spinal cord stimulation was largest when the spinal electrodes were placed over the dorsal root entry zone.Repeated pairing of motor cortex and spinal cord stimulation caused lasting increases in evoked potentials from both sites, but only if the time between the stimuli was optimal.Both immediate and lasting effects of paired stimulation are likely mediated by convergence of descending motor circuits and large diameter afferents onto common interneurons in the cervical spinal cord. Abstract Convergent activity in neural circuits can generate changes at their intersection. The rules of paired electrical stimulation are best understood for protocols that stimulate input circuits and their targets. We took a different approach by targeting the interaction of descending motor pathways and large diameter afferents in the spinal cord. We hypothesized that pairing stimulation of motor cortex and cervical spinal cord would strengthen motor responses through their convergence. We placed epidural electrodes over motor cortex and the dorsal cervical spinal cord in rats; motor evoked potentials (MEPs) were measured from biceps. MEPs evoked from motor cortex were robustly augmented with spinal epidural stimulation delivered at an intensity below the threshold for provoking an MEP. Augmentation was critically dependent on the timing and position of spinal stimulation. When the spinal stimulation was timed to coincide with the descending volley from motor cortex stimulation, MEPs were more than doubled. We then tested the effect of repeated pairing of motor cortex and spinal stimulation. Repetitive pairing caused strong augmentation of cortical MEPs and spinal excitability that lasted up to an hour after just 5 min of pairing. Additional physiology experiments support the hypothesis that paired stimulation is mediated by convergence of descending motor circuits and large diameter afferents in the spinal cord. The large effect size of this protocol and the conservation of the circuits being manipulated between rats and humans makes it worth pursuing for recovery of sensorimotor function after injury to the central nervous system. PMID:28752624

Paired motor cortex and cervical epidural electrical stimulation timed to converge in the spinal cord promotes lasting increases in motor responses.

PubMed

Mishra, Asht M; Pal, Ajay; Gupta, Disha; Carmel, Jason B

2017-11-15

Pairing motor cortex stimulation and spinal cord epidural stimulation produced large augmentation in motor cortex evoked potentials if they were timed to converge in the spinal cord. The modulation of cortical evoked potentials by spinal cord stimulation was largest when the spinal electrodes were placed over the dorsal root entry zone. Repeated pairing of motor cortex and spinal cord stimulation caused lasting increases in evoked potentials from both sites, but only if the time between the stimuli was optimal. Both immediate and lasting effects of paired stimulation are likely mediated by convergence of descending motor circuits and large diameter afferents onto common interneurons in the cervical spinal cord. Convergent activity in neural circuits can generate changes at their intersection. The rules of paired electrical stimulation are best understood for protocols that stimulate input circuits and their targets. We took a different approach by targeting the interaction of descending motor pathways and large diameter afferents in the spinal cord. We hypothesized that pairing stimulation of motor cortex and cervical spinal cord would strengthen motor responses through their convergence. We placed epidural electrodes over motor cortex and the dorsal cervical spinal cord in rats; motor evoked potentials (MEPs) were measured from biceps. MEPs evoked from motor cortex were robustly augmented with spinal epidural stimulation delivered at an intensity below the threshold for provoking an MEP. Augmentation was critically dependent on the timing and position of spinal stimulation. When the spinal stimulation was timed to coincide with the descending volley from motor cortex stimulation, MEPs were more than doubled. We then tested the effect of repeated pairing of motor cortex and spinal stimulation. Repetitive pairing caused strong augmentation of cortical MEPs and spinal excitability that lasted up to an hour after just 5 min of pairing. Additional physiology experiments support the hypothesis that paired stimulation is mediated by convergence of descending motor circuits and large diameter afferents in the spinal cord. The large effect size of this protocol and the conservation of the circuits being manipulated between rats and humans makes it worth pursuing for recovery of sensorimotor function after injury to the central nervous system. © 2017 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

[The metabolic profilings study of serum and spinal cord from acute spinal cord injury rats ¹H NMR spectroscopy].

PubMed

Hu, Hua-Hui; Huang, Xiao-Long; Quan, Ren-Fu; Yang, Zong-Bao; Xu, Jing-Jing

2017-02-25

To establish the rat model of acute spinal cord injury, followed by aprimary study on this model with ¹H NMR based on metabonomics and to explore the metabonomics and biomarkers of spinal cord injury rat. Twenty eight-week-old adult male SD rats of clean grade, with body weight of (200±10) g, were divided into sham operation group and model group in accordance with the law of random numbers, and every group had 10 rats. The rats of sham operation group were operated without damaging the spinal cord, and rats of model group were made an animal model of spinal cord incomplete injury according to the modified Allen's method. According to BBB score to observate the motor function of rats on the 1th, 5th, and 7th days after surgery. Postoperative spinal cord tissue was collected in order to pathologic observation at the 7th day, and the metabolic profilings of serum and spinal cord from spinal cord injury rats were studied by ¹H NMR spectroscopy. The hindlimb motion of rats did not obviously change in sham operation group, there was no significant difference at each time point;and rats of model group occurred flaccid paralysis of both lower extremities, there was a significant difference at each time; there was significant differences between two groups at each time. Pathological results showed the spinal cord structure was normal with uniform innervation in shame group, while in model group, the spinal cord structure was mussy, and the neurons were decreased, with inflammatory cells and necrotic tissue. Analysis of metabonomics showed that concentration of very low density fat protein (VLDL), low density fat protein (LDL), glutamine, citric acid, dimethylglycine (DMG) in the serum and glutathione, 3-OH-butyrate, N-Acetyl-L-aspartic acid (NAA), glycerophosphocholine (GPC), glutamic acid, and ascorbate in spinal cord had significant changes( P <0.05). There are significant differences in metabolic profile from serum and spinal cord sample between model group and sham operation group, it conduces to explain the changes of small molecular substances in serum and spinal cord tissue after spinal cord injury, this provides the research basis for targeted research on the role of metabolic markers in patients with acute spinal cord injury.

Spinal cord herniation following cervical meningioma excision: a rare clinical entity and review of literature.

PubMed

Aiyer, Siddharth N; Shetty, Ajoy Prasad; Kanna, Rishi; Maheswaran, Anupama; Rajasekaran, S

2016-05-01

Spinal cord herniation following surgery is an extremely uncommon clinical condition with very few reports in published literature. This condition usually occurs as a spontaneous idiopathic phenomenon often in the thoracic spine or following a scenario of post traumatic spinal cord/nerve root injury. Rarely has it been reported following spinal cord tumor surgery. To document a case of cervical spinal cord herniation as a late onset complication following spinal cord tumor surgery with an atypical presentation of monoparesis. Case report. We describe the clinical presentation, operative procedure, post operative outcome and review of literature of this rare clinical condition. A 57-year-old man presented with right upper limb monoparesis due to a spinal cord herniation 6 years after a cervical intradural meningioma excision. The patients underwent surgery to reduce the herniation and duroplasty with subsequent complete resolution of symptoms. Spinal cord herniation must be considered as differential diagnosis in scenarios of spinal cord tumor excision presenting with late onset neurological deficit. These cases may present as paraparesis, Brown-sequard syndrome and rarely as in our case as monoparesis.

Experimental spinal cord trauma: a review of mechanically induced spinal cord injury in rat models.

PubMed

Abdullahi, Dauda; Annuar, Azlina Ahmad; Mohamad, Masro; Aziz, Izzuddin; Sanusi, Junedah

2017-01-01

It has been shown that animal spinal cord compression (using methods such as clips, balloons, spinal cord strapping, or calibrated forceps) mimics the persistent spinal canal occlusion that is common in human spinal cord injury (SCI). These methods can be used to investigate the effects of compression or to know the optimal timing of decompression (as duration of compression can affect the outcome of pathology) in acute SCI. Compression models involve prolonged cord compression and are distinct from contusion models, which apply only transient force to inflict an acute injury to the spinal cord. While the use of forceps to compress the spinal cord is a common choice due to it being inexpensive, it has not been critically assessed against the other methods to determine whether it is the best method to use. To date, there is no available review specifically focused on the current compression methods of inducing SCI in rats; thus, we performed a systematic and comprehensive publication search to identify studies on experimental spinalization in rat models, and this review discusses the advantages and limitations of each method.

Acute non-traumatic spinal subdural haematoma: an unusual aetiology.

PubMed

Seizeur, Romuald; Ahmed, Seddik Sid; Simon, Alexandre; Besson, Gérard; Forlodou, Pierre

2009-06-01

We report an unusual case of a spinal subdural haematoma associated with a ruptured spinal aneurysm. The delayed diagnosis or misdiagnosis of this rare entity can have disastrous consequences. We discuss various possible aetiologies and its association with spinal aneurysms.

Management of chronic spinal cord dysfunction.

PubMed

Abrams, Gary M; Ganguly, Karunesh

2015-02-01

Both acute and chronic spinal cord disorders present multisystem management problems to the clinician. This article highlights key issues associated with chronic spinal cord dysfunction. Advances in symptomatic management for chronic spinal cord dysfunction include use of botulinum toxin to manage detrusor hyperreflexia, pregabalin for management of neuropathic pain, and intensive locomotor training for improved walking ability in incomplete spinal cord injuries. The care of spinal cord dysfunction has advanced significantly over the past 2 decades. Management and treatment of neurologic and non-neurologic complications of chronic myelopathies ensure that each patient will be able to maximize their functional independence and quality of life.

Spinal Accessory Motor Neurons in the Mouse: A Special Type of Branchial Motor Neuron?

PubMed

Watson, Charles; Tvrdik, Petr

2018-04-16

The spinal accessory nerve arises from motor neurons in the upper cervical spinal cord. The axons of these motor neurons exit dorsal to the ligamentum denticulatum and form the spinal accessory nerve. The nerve ascends in the spinal subarachnoid space to enter the posterior cranial fossa through the foramen magnum. The spinal accessory nerve then turns caudally to exit through the jugular foramen alongside the vagus and glossopharyngeal nerves, and then travels to supply the sternomastoid and trapezius muscles in the neck. The unusual course of the spinal accessory nerve has long prompted speculation that it is not a typical spinal motor nerve and that it might represent a caudal remnant of the branchial motor system. Our cell lineage tracing data, combined with images from public databases, show that the spinal accessory motor neurons in the mouse transiently express Phox2b, a transcription factor that is required for development of brain stem branchial motor nuclei. While this is strong prima facie evidence that the spinal accessory motor neurons should be classified as branchial motor, the evolutionary history of these motor neurons in anamniote vertebrates suggests that they may be considered to be an atypical branchial group that possesses both branchial and somatic characteristics. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Spinal hyperostosis as an important sign indicating spine injuries on postmortem computed tomography.

PubMed

Oshima, Toru; Hayashida, Mitsumasa; Ohtani, Maki; Hashimoto, Manabu; Takahashi, Satoshi; Ishiyama, Koichi; Otani, Takahiro; Koga, Makoto; Sugawara, Makoto; Mimasaka, Sohtaro

2014-07-01

Although spine injuries are not always detectable on postmortem computed tomography (PMCT), spinal hyperostosis, an important risk factor for spine injury, is relatively easily detectable on PMCT. We therefore examined the utility of the detection of spinal hyperostosis on PMCT as an indicator of spine injury. Full-body PMCT images of 88 autopsy cases with a bruise on the face or forehead but no identifiable skull fracture were reviewed prior to autopsy for the identification and classification of spinal hyperostosis. Spine injuries were observed in 56.0% of cases with spinal hyperostosis and 1.6% of cases without spinal hyperostosis. Among the cases with spinal hyperostosis, spine injuries were observed in 66.7% of cases at stage 2 or 3 and in 88.9% of cases at stage 3. Spine injuries were diagnosed on PMCT in 33.3% of cases prior to autopsy. A significant association was found between spinal hyperostosis and presence of spine injury that cannot be detected on PMCT, indicating that the identification of spinal hyperostosis on PMCT may assist in detecting spine injuries. This finding suggests that investigation of the presence of spine injury based on the identification of spinal hyperostosis on PMCT may assist in determining the correct cause of death by autopsy. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Targeting Lumbar Spinal Neural Circuitry by Epidural Stimulation to Restore Motor Function After Spinal Cord Injury.

PubMed

Minassian, Karen; McKay, W Barry; Binder, Heinrich; Hofstoetter, Ursula S

2016-04-01

Epidural spinal cord stimulation has a long history of application for improving motor control in spinal cord injury. This review focuses on its resurgence following the progress made in understanding the underlying neurophysiological mechanisms and on recent reports of its augmentative effects upon otherwise subfunctional volitional motor control. Early work revealed that the spinal circuitry involved in lower-limb motor control can be accessed by stimulating through electrodes placed epidurally over the posterior aspect of the lumbar spinal cord below a paralyzing injury. Current understanding is that such stimulation activates large-to-medium-diameter sensory fibers within the posterior roots. Those fibers then trans-synaptically activate various spinal reflex circuits and plurisegmentally organized interneuronal networks that control more complex contraction and relaxation patterns involving multiple muscles. The induced change in responsiveness of this spinal motor circuitry to any residual supraspinal input via clinically silent translesional neural connections that have survived the injury may be a likely explanation for rudimentary volitional control enabled by epidural stimulation in otherwise paralyzed muscles. Technological developments that allow dynamic control of stimulation parameters and the potential for activity-dependent beneficial plasticity may further unveil the remarkable capacity of spinal motor processing that remains even after severe spinal cord injuries.

Cervical spinal epidural arteriovenous fistula with coexisting spinal anterior spinal artery aneurysm presenting as subarachnoid hemorrhage--case report.

PubMed

Nakagawa, Ichiro; Park, Hun-Soo; Hironaka, Yasuo; Wada, Takeshi; Kichikawa, Kimihiko; Nakase, Hiroyuki

2014-01-01

Hemorrhagic presentation of spinal epidural arteriovenous fistulas (AVFs) is rare in patients with cervical spinal vascular lesions. The present report describes a patient with cervical spine epidural AVFs associated with anterior spinal artery aneurysm at the same vertebral level presenting with subarachnoid hemorrhage. A 54-year-old man presented with sudden onset of headache. Computed tomography of the head showed subarachnoid hemorrhage. Diagnostic angiography revealed an epidural AVF located at the C1-2 level that was fed mainly by the dorsal somatic branches of the segmental arteries from the radicular artery and anterior spinal artery. This AVF drained only into the epidural veins without perimedullary venous reflux. Further, there was a 4-mm anterior spinal artery aneurysm in the vicinity of the fistula that was thought to be the cause of the hemorrhage. Endovascular transarterial fistulas embolization from the right radicular artery was performed to eliminate the AVF and to reduce hemodynamic stress on the aneurysm. No new symptoms developed after the treatment and discharged without neurological deficits. The aneurysm was noted to be reduced in size after the treatment and totally disappeared by 1 year later, according to follow-up angiography. Anterior spinal artery aneurysm from a separate vascular distribution may coexist with spinal epidural AVFs. In the setting of spinal subarachnoid hemorrhage, comprehensive imaging is indicated to rule out such lesions. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Central glucocorticoid receptors regulate the upregulation of spinal cannabinoid-1 receptors after peripheral nerve injury in rats.

PubMed

Wang, Shuxing; Lim, Grewo; Mao, Ji; Sung, Backil; Yang, Liling; Mao, Jianren

2007-09-01

Previous studies have shown that peripheral nerve injury upregulated both glucocorticoid receptors (GR) and cannabinoid-1 receptors (CB1R) within the spinal cord dorsal horn in rats. However, the relationship between the expression of spinal GR and CB1R after nerve injury remains unclear. Here, we examined the hypothesis that the upregulation of spinal CB1R induced by chronic constriction nerve injury (CCI) in rats would be regulated by spinal GR. CCI induced the upregulation of spinal CB1R primarily within the ipsilateral spinal cord dorsal horn as revealed by Western blot and immunohistochemistry. The expression of CB1R in CCI rats was substantially attenuated by intrathecal treatment with either the GR antagonist RU38486 or a GR antisense oligonucleotide given twice daily for postoperative day 1-6, whereas the expression of spinal CB1R was enhanced following intrathecal administration of a GR sense oligonucleotide twice daily for postoperative day 1-6. Furthermore, the upregulation of spinal CB1R after nerve injury was prevented in adrenalectomized rats, which was at least partially restored with the intrathecal administration of an exogenous GR agonist dexamethasone, indicating that corticosteroids (endogenous GR agonists) were critical to spinal GR actions. Since the development of neuropathic pain behaviors in CCI rats was attenuated by either RU38486 or a GR antisense oligonucleotide, these results suggest that CB1R is a downstream target for spinal GR actions contributory to the mechanisms of neuropathic pain.

Traumatic subdural hematoma in the lumbar spine.

PubMed

Song, Jenn-Yeu; Chen, Yu-Hao; Hung, Kuang-Chen; Chang, Ti-Sheng

2011-10-01

Traumatic spinal subdural hematoma is rare and its mechanism remains unclear. This intervention describes a patient with mental retardation who was suffering from back pain and progressive weakness of the lower limbs following a traffic accident. Magnetic resonance imaging of the spine revealed a lumbar subdural lesion. Hematoma was identified in the spinal subdural space during an operation. The muscle power of both lower limbs recovered to normal after surgery. The isolated traumatic spinal subdural hematoma was not associated with intracranial subdural hemorrhage. A spinal subdural hematoma should be considered in the differential diagnosis of spinal cord compression, especially for patients who have sustained spinal trauma. Emergency surgical decompression is usually the optimal treatment for a spinal subdural hematoma with acute deterioration and severe neurological deficits. Copyright © 2011. Published by Elsevier B.V.

Injury-induced ctgfa directs glial bridging and spinal cord regeneration in zebrafish

PubMed Central

Mokalled, Mayssa H.; Patra, Chinmoy; Dickson, Amy L.; Endo, Toyokazu; Stainier, Didier Y. R.; Poss, Kenneth D.

2016-01-01

Unlike mammals, zebrafish efficiently regenerate functional nervous system tissue after major spinal cord injury. Whereas glial scarring presents a roadblock for mammalian spinal cord repair, glial cells in zebrafish form a bridge across severed spinal cord tissue and facilitate regeneration, a relatively unexplored process. Here, we performed a genome-wide profiling screen for secreted factors that are upregulated during zebrafish spinal cord regeneration. We find that connective tissue growth factor a (ctgfa) is induced in and around glial cells that participate in initial bridging events. Mutations in ctgfa disrupt spinal cord repair, while transgenic ctgfa overexpression and local human CTGF recombinant protein delivery accelerate bridging and functional regeneration. Our study reveals that CTGF is necessary and sufficient to stimulate glial bridging and natural spinal cord regeneration. PMID:27811277

Brain protection by methylprednisolone in rats with spinal cord injury.

PubMed

Chang, Chia-Mao; Lee, Ming-Hsueh; Wang, Ting-Chung; Weng, Hsu-Huei; Chung, Chiu-Yen; Yang, Jen-Tsung

2009-07-01

Traumatic spinal cord injury is clinically treated by high doses of methylprednisolone. However, the effect of methylprednisolone on the brain in spinal cord injury patients has been little investigated. This experimental study examined Bcl-2 and Bax protein expression and Nissl staining to evaluate an apoptosis-related intracellular signaling event and final neuron death, respectively. Spinal cord injury produced a significant apoptotic change and cell death not only in the spinal cord but also in the supraventricular cortex and hippocampal cornu ammonis 1 region in the rat brains. The treatment of methylprednisolone increased the Bcl-2/Bax ratio and prevented neuron death for 1-7 days after spinal cord injury. These findings suggest that rats with spinal cord injury show ascending brain injury that could be restricted through methylprednisolone management.

Clinical and imaging features of spinal cord type of neuro Behçet disease: A case report and systematic review.

PubMed

Liu, Hui-Miao; Dong, Ci; Zhang, Yong-Zhi; Tian, Ya-Yun; Chen, Hong-Xu; Zhang, Sai; Li, Na; Gu, Ping

2017-10-01

To investigate the clinical and MRI characteristics of spinal cord nerve Behçet's disease. One patient with spinal cord nerve Behçet's disease was admitted to our hospital at October 20, 2015. Spinal cord nerve Behçet's disease. Retrospective analysis was performed on such case as well as 16 cases of spinal cord nerve Behçet's disease reported in China or abroad. Seventeen cases of spinal cord type of neuro Behçet's disease include 13 men and 4 women, with an average age of onset of 34.8 years old. The mean time from Behçet's disease symptoms to spinal cord involvement were 10.8 years. The initial symptom in one case was spinal cord injury, and another 4 cases had a recurrence course. The most common performance of spinal cord injury was sensory disturbance (82.4%), following by weakness (76.5%), sphincter or sexual dysfunction (58.8%), and pain in back, backside of neck or lower chest (29.4%). The number of cells was slightly increased or the protein level was increased in cerebrospinal fluid test. And the water channel protein antibody and oligoclonal band of serum levels were all negative. The spinal cord injury involved more than 3 vertebral bodies in 10 cases, and involved more than half of spinal cord in sagittal plane in 8 cases. In acute stage, shock therapy with large dose of glucocorticoid was generally applied both in China and abroad. The clinical features of spinal cord nerve Behçet's disease were various, making it easily misdiagnosed. Longitudinal extensive transverse myelitis performs as a characteristic manifestation.

Image analysis of open-door laminoplasty for cervical spondylotic myelopathy: comparing the influence of cord morphology and spine alignment.

PubMed

Lin, Bon-Jour; Lin, Meng-Chi; Lin, Chin; Lee, Meei-Shyuan; Feng, Shao-Wei; Ju, Da-Tong; Ma, Hsin-I; Liu, Ming-Ying; Hueng, Dueng-Yuan

2015-10-01

Previous studies have identified the factors affecting the surgical outcome of cervical spondylotic myelopathy (CSM) following laminoplasty. Nonetheless, the effect of these factors remains controversial. It is unknown about the association between pre-operative cervical spinal cord morphology and post-operative imaging result following laminoplasty. The goal of this study is to analyze the impact of pre-operative cervical spinal cord morphology on post-operative imaging in patients with CSM. Twenty-six patients with CSM undergoing open-door laminoplasty were classified according to pre-operative cervical spine bony alignment and cervical spinal cord morphology, and the results were evaluated in terms of post-operative spinal cord posterior drift, and post-operative expansion of the antero-posterior dura diameter. By the result of study, pre-operative spinal cord morphology was an effective classification in predicting surgical outcome - patients with anterior convexity type, description of cervical spinal cord morphology, had more spinal cord posterior migration than those with neutral or posterior convexity type after open-door laminoplasty. Otherwise, the interesting finding was that cervical spine Cobb's angle had an impact on post-operative spinal cord posterior drift in patients with neutral or posterior convexity type spinal cord morphology - the degree of kyphosis was inversely proportional to the distance of post-operative spinal cord posterior drift, but not in the anterior convexity type. These findings supported that pre-operative cervical spinal cord morphology may be used as screening for patients undergoing laminoplasty. Patients having neutral or posterior convexity type spinal cord morphology accompanied with kyphotic deformity were not suitable candidates for laminoplasty. Copyright © 2015 Elsevier B.V. All rights reserved.

Magnetic resonance imaging tractography as a diagnostic tool in patients with spinal cord injury treated with human embryonic stem cells.

PubMed

Shroff, Geeta

2017-02-01

Introduction Spinal cord injury is a cause of severe disability and mortality. The pharmacological and non-pharmacological methods used, are unable to improve the quality of life in spinal cord injury. Spinal disorders have been treated with human embryonic stem cells. Magnetic resonance imaging and tractography were used as imaging modality to document the changes in the damaged cord, but the magnetic resonance imaging tractography was seen to be more sensitive in detecting the changes in the spinal cord. The present study was conducted to evaluate the diagnostic modality of magnetic resonance imaging tractography to determine the efficacy of human embryonic stem cells in chronic spinal cord injury. Materials and methods The study included the patients with spinal cord injury for whom magnetic resonance imaging tractography was performed before and after the therapy. Omniscan (gadodiamide) magnetic resonance imaging tractography was analyzed to assess the spinal defects and the improvement by human embryonic stem cell treatment. The patients were also scored by American Spinal Injury Association scale. Results Overall, 15 patients aged 15-44 years with clinical manifestations of spinal cord injury had magnetic resonance imaging tractography performed. The average treatment period was nine months. The majority of subjects ( n = 13) had American Spinal Injury Association score A, and two patients were at score C at the beginning of therapy. At the end of therapy, 10 patients were at score A, two patients were at score B and three patients were at score C. Improvements in patients were clearly understood through magnetic resonance imaging tractography as well as in clinical signs and symptoms. Conclusion Magnetic resonance imaging tractography can be a crucial diagnostic modality to assess the improvement in spinal cord injury patients.

[APPLICATION OF THREE DIMENSIONAL PRINTING ON MANUFACTURING BIONIC SCAFFOLDS OF SPINAL CORD IN RATS].

PubMed

Chen, Yisheng; Wang, Jingjing; Chen, Xuyi; Chen, Chong; Tu, Yue; Zhang, Sai; Li, Xiaohong

2015-03-01

To fabricate the bionic scaffolds of rat spinal cord by combining three dimensional (3D) printer and 3D software, so as to lay the foundation of theory and technology for the manufacture of scaffolds by using biomaterials. Three female Sprague Dawley rats were scanned by 7.0T MRI to obtain the shape and position data of the cross section and gray matter of T8 to T10 spinal cord. Combined with data of position and shape of nerve conduction beam, the relevant data were obtained via Getdata software. Then the 3D graphics were made and converted to stereolithography (STL) format by using SolidWorks software. Photosensitive resin was used as the materials of spinal cord scaffolds. The bionic scaffolds were fabricated by 3D printer. MRI showed that the section shape of T8 to T10 segments of the spinal cord were approximately oval with a relatively long sagittal diameter of (2.20 ± 0.52) mm and short transverse diameter of (2.05 ± 0.24) mm, and the data of nerve conduction bundle were featured in the STL format. The spinal cord bionic scaffolds of the target segments made by 3D printer were similar to the spinal cord of rat in the morphology and size, and the position of pores simulated normal nerve conduction of rat spinal cord. Spinal cord scaffolds produced by 3D printer which have similar shape and size of normal rat spinal cord are more bionic, and the procedure is simple. This technology combined with biomaterials is also promising in spinal cord repairing after spinal cord injury.

Cervical spinal stenosis and sports-related cervical cord neurapraxia in children.

PubMed

Boockvar, J A; Durham, S R; Sun, P P

2001-12-15

Congenital spinal stenosis has been demonstrated to contribute to cervical cord neurapraxia after cervical spinal cord injury in adult athletes. A sagittal canal diameter <14 mm and/or a Torg ratio (sagittal diameter of the spinal canal: midcervical sagittal vertebral body diameter) of <0.8 are indicative of significant cervical spinal stenosis. Although sports-related cervical spine injuries are common in children, the role of congenital cervical stenosis in the etiology of these injuries remains unclear. The authors measured the sagittal canal diameter and the Torg ratio in children presenting with cervical cord neurapraxia resulting from sports-related cervical spinal cord injuries to determine the presence of congenital spinal stenosis. A total of 13 children (9 male, 4 female) presented with cervical cord neurapraxia after a sports-related cervical spinal cord injury. Age ranged from 7 to 15 years (mean +/- SD, 11.5 +/- 2.7 years). The sports involved were football (n = 4), wrestling (n = 2), hockey (n = 2), and soccer, gymnastics, baseball, kickball, and pogosticking (n = 1 each). Lateral cervical spine radiographs were used to determine the sagittal canal diameter and the Torg ratio at C4. The sagittal canal diameter (mean +/- SD, 17.58 +/- 1.63 mm) and the Torg ratio (mean +/- SD, 1.20 +/- 0.24) were normal in all of these children. Using the sagittal canal diameter and the Torg ratio as a measurement of congenital spinal stenosis, the authors did not find evidence of congenital cervical spinal stenosis in a group of children with sports-related cervical spinal cord neurapraxia. The occurrence of cervical cord neurapraxia in pediatric patients can be attributed to the mobility of the pediatric spine rather than to congenital cervical spinal stenosis.

In-vivo spinal nerve sensing in MISS using Raman spectroscopy

NASA Astrophysics Data System (ADS)

Chen, Hao; Xu, Weiliang; Broderick, Neil

2016-04-01

In modern Minimally Invasive Spine Surgery (MISS), lack of visualization and haptic feedback information are the main obstacles. The spinal cord is a part of the central nervous system (CNS). It is a continuation of the brain stem, carries motor and sensory messages between CNS and the rest of body, and mediates numerous spinal reflexes. Spinal cord and spinal nerves are of great importance but vulnerable, once injured it may result in severe consequences to patients, e.g. paralysis. Raman Spectroscopy has been proved to be an effective and powerful tool in biological and biomedical applications as it works in a rapid, non-invasive and label-free way. It can provide molecular vibrational features of tissue samples and reflect content and proportion of protein, nucleic acids lipids etc. Due to the distinct chemical compositions spinal nerves have, we proposed that spinal nerves can be identified from other types of tissues by using Raman spectroscopy. Ex vivo experiments were first done on samples taken from swine backbones. Comparative spectral data of swine spinal cord, spinal nerves and adjacent tissues (i.e. membrane layer of the spinal cord, muscle, bone and fatty tissue) are obtained by a Raman micro-spectroscopic system and the peak assignment is done. Then the average spectra of all categories of samples are averaged and normalized to the same scale to see the difference against each other. The results verified the feasibility of spinal cord and spinal nerves identification by using Raman spectroscopy. Besides, a fiber-optic Raman sensing system including a miniature Raman sensor for future study is also introduced. This Raman sensor can be embedded into surgical tools for MISS.

JNK-induced MCP-1 production in spinal cord astrocytes contributes to central sensitization and neuropathic pain

PubMed Central

Gao, Yong-Jing; Zhang, Ling; Samad, Omar Abdel; Suter, Marc R.; Yasuhiko, Kawasaki; Xu, Zhen-Zhong; Park, Jong-Yeon; Lind, Anne-Li; Ma, Qiufu; Ji, Ru-Rong

2009-01-01

Our previous study showed that activation of c-jun-N-terminal kinase (JNK) in spinal astrocytes plays an important role in neuropathic pain sensitization. We further investigated how JNK regulates neuropathic pain. In cultured astrocytes, TNF-α transiently activated JNK via TNF receptor-1. Cytokine array indicated that the chemokine CCL2/MCP-1 (monocyte chemoattractant protein-1) was strongly induced by the TNF-α/JNK pathway. MCP-1 upregulation by TNF-α was dose-dependently inhibited by the JNK inhibitors SP600125 and D-JNKI-1. Spinal injection of TNF-α produced JNK-dependent pain hypersensitivity and MCP-1 upregulation in the spinal cord. Further, spinal nerve ligation (SNL) induced persistent neuropathic pain and MCP-1 upregulation in the spinal cord, and both were suppressed by D-JNKI-1. Remarkably, MCP-1 was primarily induced in spinal cord astrocytes after SNL. Spinal administration of MCP-1 neutralizing antibody attenuated neuropathic pain. Conversely, spinal application of MCP-1 induced heat hyperalgesia and phosphorylation of extracellular signal-regulated kinase (ERK) in superficial spinal cord dorsal horn neurons, indicative of central sensitization (hyperactivity of dorsal horn neurons). Patch clamp recordings in lamina II neurons of isolated spinal cord slices showed that MCP-1 not only enhanced spontaneous excitatory synaptic currents (sEPSCs) but also potentiated NMDA- and AMPA-induced currents. Finally, the MCP-1 receptor CCR2 was expressed in neurons and some non-neuronal cells in the spinal cord. Taken together, we have revealed a previously unknown mechanism of MCP-1 induction and action. MCP-1 induction in astrocytes following JNK activation contributes to central sensitization and neuropathic pain facilitation by enhancing excitatory synaptic transmission. Inhibition of the JNK/MCP-1 pathway may provide a new therapy for neuropathic pain management. PMID:19339605

White matter organization in cervical spinal cord relates differently to age and control of grip force in healthy subjects.

PubMed

Lindberg, Påvel G; Feydy, Antoine; Maier, Marc A

2010-03-17

Diffusion tensor imaging (DTI) can be used to elucidate relations between CNS structure and function. We hypothesized that the degree of spinal white matter organization relates to the accuracy of control of grip force. Healthy subjects of different age were studied using DTI and visuomotor tracking of precision grip force. The latter is a prime component of manual dexterity. A regional analysis of spinal white matter [fractional anisotropy (FA)] across multiple cervical levels (C2-C3, C4-C5, and C6-C7) and in different regions of interest (left and right lateral or medial spinal cord) was performed. FA was highest at the C2-C3 level, higher on the right than the left side, and higher in the lateral than in the medial spinal cord (p < 0.001). FA of whole cervical spinal cord (C2-C7) was lower in subjects with high tracking error (r = -0.56, p = 0.004) and decreased with age (r = -0.63, p = 0.001). A multiple regression analysis revealed an independent contribution of each predictor (semipartial correlations: age, r = -0.55, p < 0.001; tracking error, r = -0.49, p = 0.003). The closest relation between FA and tracking error was found at the C6-C7 level in the lateral spinal cord, in which the corticospinal tract innervates spinal circuitry controlling hand and digit muscles. FA of the medial spinal cord correlated consistently with age across all cervical levels, whereas FA of the lateral spinal cord did not. The results suggest (1) a functionally relevant specialization of lateral spinal cord white matter and (2) an increased sensitivity to age-related decline in medial spinal cord white matter in healthy subjects.

Post dural puncture headache after spinal anaesthesia for caesarean section: a comparison of 25 g Quincke, 27 g Quincke and 27 g Whitacre spinal needles.

PubMed

Shaikh, Jan Muhammad; Memon, Amna; Memon, Muhammad Ali; Khan, Majida

2008-01-01

To compare the frequency and severity of post dural puncture headache in obstetric patients using 25G Quincke, 27G Quincke and 27G Whitacre spinal needles. Comparative, randomized, double-blind, interventional study. Liaquat University Hospital Hyderabad from October 2005 to December 2006. 480 ASA I-II full term pregnant women, 18 to 45 years of age, scheduled for elective Caesarean section, under spinal anaesthesia, were randomized into three groups: Group I (25G Quincke spinal needle: n=168), Group II (27G Quincke spinal needle: n=160) and Group III (27G Whitacre spinal needle: n=152). Spinal anaesthesia was performed with 1.5-2.0 ml 0.75% hyperbaric bupivacaine using 25G Quincke spinal needle (Group I), 27G Quincke spinal needle (Group II) and 27G Whitacre spinal needle (Group III) at L3-4 inter-vertebral space. Each patient was assessed daily for four consecutive days following Caesarean section. Frequency and severity and of postdural puncture headache (PDPH) were recorded. Data were analyzed using SPSS-11. Frequency of PDPH following the use of 25G Quincke (Group I), 27G Quincke (Group II) and 27G Whitacre (Group III) spinal needles was 8.3% (14/168), 3.8% (6/160) and 2.0% (3/152) respectively. In Group I, PDPH was mild in 5 patients, moderate in 7 patients and severe in 2 patients. In Group II, it was mild in 2, moderate in 3 and severe in 1 patient. In group III, it was mild in 2 and moderate in 1 patient. Severe PDPH did not occur in Group III. Most of the patients with PDPH developed it on 1st and 2nd postoperative day. When using a 27G Whitacre spinal needle, the frequency and severity of PDPH was significantly lower than when a 25G Quincke or 27G Quincke needle was used.

A new model of the spinal locomotor networks of a salamander and its properties.

PubMed

Liu, Qiang; Yang, Huizhen; Zhang, Jinxue; Wang, Jingzhuo

2018-05-22

A salamander is an ideal animal for studying the spinal locomotor network mechanism of vertebrates from an evolutionary perspective since it represents the transition from an aquatic to a terrestrial animal. However, little is known about the spinal locomotor network of a salamander. A spinal locomotor network model is a useful tool for exploring the working mechanism of the spinal networks of salamanders. A new spinal locomotor network model for a salamander is built for a three-dimensional (3D) biomechanical model of the salamander using a novel locomotion-controlled neural network model. Based on recent experimental data on the spinal circuitry and observational results of gaits of vertebrates, we assume that different interneuron sets recruited for mediating the frequency of spinal circuits are also related to the generation of different gaits. The spinal locomotor networks of salamanders are divided into low-frequency networks for walking and high-frequency networks for swimming. Additionally, a new topological structure between the body networks and limb networks is built, which only uses the body networks to coordinate the motion of limbs. There are no direct synaptic connections among limb networks. These techniques differ from existing salamander spinal locomotor network models. A simulation is performed and analyzed to validate the properties of the new spinal locomotor networks of salamanders. The simulation results show that the new spinal locomotor networks can generate a forward walking gait, a backward walking gait, a swimming gait, and a turning gait during swimming and walking. These gaits can be switched smoothly by changing external inputs from the brainstem. These properties are consistent with those of a real salamander. However, it is still difficult for the new spinal locomotor networks to generate highly efficient turning during walking, 3D swimming, nonrhythmic movements, and so on. New experimental data are required for further validation.

Effects of whole spine alignment patterns on neck responses in rear end impact.

PubMed

Sato, Fusako; Odani, Mamiko; Miyazaki, Yusuke; Yamazaki, Kunio; Östh, Jonas; Svensson, Mats

2017-02-17

The aim of this study was to investigate the whole spine alignment in automotive seated postures for both genders and the effects of the spinal alignment patterns on cervical vertebral motion in rear impact using a human finite element (FE) model. Image data for 8 female and 7 male subjects in a seated posture acquired by an upright open magnetic resonance imaging (MRI) system were utilized. Spinal alignment was determined from the centers of the vertebrae and average spinal alignment patterns for both genders were estimated by multidimensional scaling (MDS). An occupant FE model of female average size (162 cm, 62 kg; the AF 50 size model) was developed by scaling THUMS AF 05. The average spinal alignment pattern for females was implemented in the model, and model validation was made with respect to female volunteer sled test data from rear end impacts. Thereafter, the average spinal alignment pattern for males and representative spinal alignments for all subjects were implemented in the validated female model, and additional FE simulations of the sled test were conducted to investigate effects of spinal alignment patterns on cervical vertebral motion. The estimated average spinal alignment pattern was slight kyphotic, or almost straight cervical and less-kyphotic thoracic spine for the females and lordotic cervical and more pronounced kyphotic thoracic spine for the males. The AF 50 size model with the female average spinal alignment exhibited spine straightening from upper thoracic vertebra level and showed larger intervertebral angular displacements in the cervical spine than the one with the male average spinal alignment. The cervical spine alignment is continuous with the thoracic spine, and a trend of the relationship between cervical spine and thoracic spinal alignment was shown in this study. Simulation results suggested that variations in thoracic spinal alignment had a potential impact on cervical spine motion as well as cervical spinal alignment in rear end impact condition.

Survey of spinal cord injury-induced neurogenic bladder studies using the Web of Science.

PubMed

Zou, Benjing; Zhang, Yongli; Li, Yucheng; Wang, Zantao; Zhang, Ping; Zhang, Xiyin; Wang, Bingdong; Long, Zhixin; Wang, Feng; Song, Guo; Wang, Yan

2012-08-15

To identify global trends in research on spinal cord injury-induced neurogenic bladder, through a bibliometric analysis using the Web of Science. We performed a bibliometric analysis of studies on spinal cord injury-induced neurogenic bladder using the Web of Science. Data retrieval was performed using key words "spinal cord injury", "spinal injury", "neurogenic bladder", "neuropathic bladder", "neurogenic lower urinary tract dysfunction", "neurogenic voiding dysfunction", "neurogenic urination disorder" and "neurogenic vesicourethral dysfunction". (a) published peer-reviewed articles on spinal cord injury-induced neurogenic bladder indexed in the Web of Science; (b) type of articles: original research articles and reviews; (c) year of publication: no limitation. (a) articles that required manual searching or telephone access; (b) Corrected papers and book chapters. (1) Annual publication output; (2) distribution according to journals; (3) distribution according to subject areas; (4) distribution according to country; (5) distribution according to institution; and (6) top cited publications. There were 646 research articles addressing spinal cord injury-induced neurogenic bladder in the Web of Science. Research on spinal cord injury-induced neurogenic bladder was found in the Science Citation Index-Expanded as of 1946. The United States, Ireland and Switzerland were the three major countries contributing to studies in spinal cord injury-induced neurogenic bladder in the 1970s. However, in the 1990s, the United States, the United Kingdom, the Netherlands, Germany and Japan published more papers on spinal cord injury-induced neurogenic bladder than Switzerland, and Ireland fell off the top ten countries list. In this century, the United States ranks first in spinal cord injury-induced neurogenic bladder studies, followed by France, the United Kingdom, Germany, Switzerland and Japan. Subject categories including urology, nephrology and clinical neurology, as well as rehabilitation, are represented in spinal cord injury-induced neurogenic bladder studies. From our analysis of the literature and research trends, we conclude that spinal cord injury-induced neurogenic bladder is a hot topic that will continue to generate considerable research interest in the future.

[RESEARCH PROGRESS OF THREE-DIMENSIONAL PRINTING TECHNIQUE FOR SPINAL IMPLANTS].

PubMed

Lu, Qi; Yu, Binsheng

2016-09-08

To summarize the current research progress of three-dimensional (3D) printing technique for spinal implants manufacture. The recent original literature concerning technology, materials, process, clinical applications, and development direction of 3D printing technique in spinal implants was reviewed and analyzed. At present, 3D printing technologies used to manufacture spinal implants include selective laser sintering, selective laser melting, and electron beam melting. Titanium and its alloys are mainly used. 3D printing spinal implants manufactured by the above materials and technology have been successfully used in clinical. But the problems regarding safety, related complications, cost-benefit analysis, efficacy compared with traditional spinal implants, and the lack of relevant policies and regulations remain to be solved. 3D printing technique is able to provide individual and customized spinal implants for patients, which is helpful for the clinicians to perform operations much more accurately and safely. With the rapid development of 3D printing technology and new materials, more and more 3D printing spinal implants will be developed and used clinically.

The change tendency of PI3K/Akt pathway after spinal cord injury

PubMed Central

Zhang, Peixun; Zhang, Luping; Zhu, Lei; Chen, Fangmin; Zhou, Shuai; Tian, Ting; Zhang, Yuqiang; Jiang, Xiaorui; Li, Xuekun; Zhang, Chuansen; Xu, Lin; Huang, Fei

2015-01-01

Spinal cord injury (SCI) refers to the damage of spinal cord’s structure and function due to a variety of causes. At present, many scholars have confirmed that apoptosis is the main method of secondary injury in spinal cord injury. In view of understanding the function of PI3K/Akt pathway on spinal cord injury, this study observed the temporal variation of key molecules (PI3K, Akt, p-Akt) in the PI3K/Akt pathway after spinal cord injury by immunohistochemistry and Western-blot. The results showed that the expression of PI3K, Akt and p-Akt display a sharp increase one day after the spinal cord injury, and then it decreased gradually with the time passing by, but the absolute expression was certainly higher than the normal group. These results indicate that the PI3K/Akt signaling pathway is involved in the spinal cord injury and the mechanism may be related to apoptosis. PMID:26807170

The impact of routine whole spine MRI screening in the evaluation of spinal degenerative diseases.

PubMed

Kanna, Rishi Mugesh; Kamal, Younis; Mahesh, Anupama; Venugopal, Prakash; Shetty, Ajoy Prasad; Rajasekaran, S

2017-08-01

Magnetic resonance imaging (MRI) of the spine is a sensitive investigation, which not only provides detailed images of the spinal column but also adjacent spinal regions and para-vertebral organ systems. Such incidental findings (IF) can be asymptomatic but significant. The efficacy of whole spine T2 sagittal screening in providing additional information has been demonstrated in several spinal diseases but its routine use in patients with spinal degenerative diseases has not been studied. A review of 1486 consecutive T2w whole spine screening MRI performed for cervical, thoracic or lumbar spinal imaging for degenerative diseases, was performed to document the incidence and significance of asymptomatic IF in the spinal and extra-spinal regions. 236 (15.88%) patients had IF with a M:F ratio of 102:134 and the mean age being 50.3 years. Of these, spinal IF was observed in 122 (51.7%-Group A) while extra-spinal IF was present in 114 (48.3%-Group B). In Group A, 84 patients had IF in the vertebral column and 38 patients had IF in the spinal cord. IF within the spine included vertebral haemangioma (n = 60, 4.5%), diffuse vertebral marrow changes (n = 18, 1.2%), vertebral metastasis (n = 2), incidental cord myelopathy (n = 21), intradural tumour (n = 7), and others. 33 patients required surgical intervention of the IF (2.2%). In Group B, pelvic IF were most prevalent (n = 79, 5.3%) followed by retro-peritoneal abdominal IF in 22 (1.48%) and intra-cranial IF in 9 (0.60%). 32 (2.1%) of these pathologies required further specialist medical or surgical evaluation. Routine T2 whole spine screening MRI identified 15.8% IF of the spinal and extra-spinal regions. 65 patients (4.3%) required either spine surgical intervention or other specialist care. Considering the potential advantages in identifying significant IF and the minimal extra time spent to perform whole spine screening, its application can be considered to be incorporated in routine imaging of spinal degenerative diseases.

Novel spinal instrumentation to enhance osteogenesis and fusion: a preliminary study.

PubMed

MacEwan, Matthew R; Talcott, Michael R; Moran, Daniel W; Leuthardt, Eric C

2016-09-01

OBJECTIVE Instrumented spinal fusion continues to exhibit high failure rates in patients undergoing multilevel lumbar fusion or pseudarthrosis revision; with Grade II or higher spondylolisthesis; or in those possessing risk factors such as obesity, tobacco use, or metabolic disorders. Direct current (DC) electrical stimulation of bone growth represents a unique surgical adjunct in vertebral fusion procedures, yet existing spinal fusion stimulators are not optimized to enhance interbody fusion. To develop an advanced method of applying DC electrical stimulation to promote interbody fusion, a novel osteogenic spinal system capable of routing DC through rigid instrumentation and into the vertebral bodies was fabricated. A pilot study was designed to assess the feasibility of osteogenic instrumentation and compare the ability of osteogenic instrumentation to promote successful interbody fusion in vivo to standard spinal instrumentation with autograft. METHODS Instrumented, single-level, posterior lumbar interbody fusion (PLIF) with autologous graft was performed at L4-5 in adult Toggenburg/Alpine goats, using both osteogenic spinal instrumentation (plus electrical stimulation) and standard spinal instrumentation (no electrical stimulation). At terminal time points (3 months, 6 months), animals were killed and lumbar spines were explanted for radiographic analysis using a SOMATOM Dual Source Definition CT Scanner and high-resolution Microcat II CT Scanner. Trabecular continuity, radiodensity within the fusion mass, and regional bone formation were examined to determine successful spinal fusion. RESULTS Quantitative analysis of average bone density in pedicle screw beds confirmed that electroactive pedicle screws used in the osteogenic spinal system focally enhanced bone density in instrumented vertebral bodies. Qualitative and quantitative analysis of high-resolution CT scans of explanted lumbar spines further demonstrated that the osteogenic spinal system induced solid bony fusion across the L4-5 disc space as early as 6 weeks postoperatively. In comparison, inactive spinal instrumentation with autograft was unable to promote successful interbody fusion by 6 months postoperatively. CONCLUSIONS Results of this study demonstrate that novel osteogenic spinal instrumentation supports interbody fusion through the focal delivery of DC electrical stimulation. With further technical development and scientific/clinical validation, osteogenic spinal instrumentation may offer a unique alternative to biological scaffolds and pharmaceutical adjuncts used in spinal fusion procedures.

Spinally projecting preproglucagon axons preferentially innervate sympathetic preganglionic neurons

PubMed Central

Llewellyn-Smith, I.J.; Marina, N.; Manton, R.N.; Reimann, F.; Gribble, F.M.; Trapp, S.

2015-01-01

Glucagon-like peptide-1 (GLP-1) affects central autonomic neurons, including those controlling the cardiovascular system, thermogenesis, and energy balance. Preproglucagon (PPG) neurons, located mainly in the nucleus tractus solitarius (NTS) and medullary reticular formation, produce GLP-1. In transgenic mice expressing glucagon promoter-driven yellow fluorescent protein (YFP), these brainstem PPG neurons project to many central autonomic regions where GLP-1 receptors are expressed. The spinal cord also contains GLP-1 receptor mRNA but the distribution of spinal PPG axons is unknown. Here, we used two-color immunoperoxidase labeling to examine PPG innervation of spinal segments T1–S4 in YFP-PPG mice. Immunoreactivity for YFP identified spinal PPG axons and perikarya. We classified spinal neurons receiving PPG input by immunoreactivity for choline acetyltransferase (ChAT), nitric oxide synthase (NOS) and/or Fluorogold (FG) retrogradely transported from the peritoneal cavity. FG microinjected at T9 defined cell bodies that supplied spinal PPG innervation. The deep dorsal horn of lower lumbar cord contained YFP-immunoreactive neurons. Non-varicose, YFP-immunoreactive axons were prominent in the lateral funiculus, ventral white commissure and around the ventral median fissure. In T1–L2, varicose, YFP-containing axons closely apposed many ChAT-immunoreactive sympathetic preganglionic neurons (SPN) in the intermediolateral cell column (IML) and dorsal lamina X. In the sacral parasympathetic nucleus, about 10% of ChAT-immunoreactive preganglionic neurons received YFP appositions, as did occasional ChAT-positive motor neurons throughout the rostrocaudal extent of the ventral horn. YFP appositions also occurred on NOS-immunoreactive spinal interneurons and on spinal YFP-immunoreactive neurons. Injecting FG at T9 retrogradely labeled many YFP-PPG cell bodies in the medulla but none of the spinal YFP-immunoreactive neurons. These results show that brainstem PPG neurons innervate spinal autonomic and somatic motor neurons. The distributions of spinal PPG axons and spinal GLP-1 receptors correlate well. SPN receive the densest PPG innervation. Brainstem PPG neurons could directly modulate sympathetic outflow through their spinal inputs to SPN or interneurons. PMID:25450967

Effects of vertebral column distraction on transcranial electrical stimulation-motor evoked potential and histology of the spinal cord in a porcine model.

PubMed

Yang, Jae Hyuk; Suh, Seung Woo; Modi, Hitesh N; Ramani, Easwar T; Hong, Jae Young; Hwang, Jin Ho; Jung, Woon Yong

2013-05-01

Spinal cord injury can occur following surgical procedures for correction of scoliosis and kyphosis, as these procedures produce lengthening of the vertebral column. The objective of this study was to cause spinal cord injury by vertebral column distraction and evaluate the histological changes in the spinal cord in relationship to the pattern of recovery from the spinal cord injury. Global osteotomy of all three spinal columns was performed on the ninth thoracic vertebra of sixteen pigs. The osteotomized vertebra was distracted until transcranial electrical stimulation-motor evoked potential (TES-MEP) signals disappeared or decreased by >80% compared with the baseline amplitude; this was defined as spinal cord injury. The distraction distance at which spinal cord injury occurred was measured, the distraction was released, and the TES-MEP recovery pattern was observed. A wake-up test was performed, two days of observations were made, and histological changes were evaluated in relationship to the recovery pattern. Spinal cord injury developed at a distraction distance of 20.2 ± 4.7 mm, equivalent to 3.6% of the thoracolumbar spinal length, and the distraction distance was correlated with the thoracolumbar spinal length (r = 0.632, p = 0.009). No animals exhibited complete recovery according to TES-MEP testing, eleven exhibited incomplete recovery, and five exhibited no recovery. During the two days of observation, all eleven animals with incomplete recovery showed positive responses to sensory and motor tests, whereas none of the five animals with no recovery had positive responses. On histological evaluation, three animals that exhibited no recovery all showed complete severance of nerve fibers (axotomy), whereas six animals that exhibited incomplete recovery all showed partial white-matter injury. Parallel distraction of approximately 3.6% of the thoracolumbar length after global osteotomy resulted in spinal cord injury and histological evidence of spinal cord damage. The pattern of recovery from the spinal cord injury after release of the distraction was consistent with the degree of axonal damage. Axotomy was observed in animals that exhibited no recovery on TES-MEP, and only hemorrhagic changes in the white matter were observed in animals that exhibited incomplete recovery.

Aetioepidemiological profile of spinal injury patients in Eastern Nepal.

PubMed

Lakhey, S; Jha, N; Shrestha, B P; Niraula, S

2005-10-01

This is a retrospective case series of 233 spinal injury patients admitted to the orthopaedic ward of BPKIHS from May 1997 to April 2001. The inpatient records were analysed. In all, 40.3% of spinal injuries resulted from falls from trees while cutting leaves for fodder, and 27.9% resulted from falls from first/second floors. More than 75% of total spinal injuries are largely preventable. Overall, 46.8% of our spinal injury patients had complete cord transection at the level of injury. All adolescents and adults, irrespective of age or sex, should be the target groups for community education and intervention programmes for prevention of spinal injury.

Safety of intraoperative electrophysiological monitoring (TES and EMG) for spinal and cranial lesions.

PubMed

Gazzeri, Roberto; Faiola, Andrea; Neroni, Massimiliano; Fiore, Claudio; Callovini, Giorgio; Pischedda, Mauro; Galarza, Marcelo

2013-09-01

Intraoperative motor evoked potentials (MEP) and electromyography (EMG) monitoring in patients with spinal and cranial lesions is a valuable tool for prevention of postoperative motor deficits. The purpose of this study was to determine whether electrophysiological monitoring during skull base, spinal cord, and spinal surgery might be useful for predicting postoperative motor deterioration. From January 2012 to March 2013, thirty-three consecutive patients were studied using intraoperative monitoring (Nuvasive NV-M5 System) to check the integrity of brainstem, spinal cord, and nerve roots, recording transcranial motor evoked potentials (TcMEPs) and electromyography. Changes in MEPs and EMGs were related to postoperative deficits. Preoperative diagnosis included skull base and brainstem lesions (6 patients), spinal tumors (11 patients), spinal deformity (16 cases). Using TcMEPs and EMG is a practicable and safe method. MEPs are useful in any surgery in which the brainstem and spinal cord are at risk. EMG stimulation helps to identify an optimal trans-psoas entry point for an extreme lateral lumbar interbody fusion (XLIF) approach to protect against potential nerve injury. This neural navigation technique via a surgeon-interpreted interface assists the surgical team in safely removing lesions and accessing the intervertebral disc space for minimally invasive spinal procedures.

Spinal Reflexes and Windup In Vitro: Effects of Analgesics and Anesthetics.

PubMed

Rivera-Arconada, Ivan; Roza, Carolina; Lopez-Garcia, Jose A

2016-02-01

The spinal cord is the first relay center for nociceptive information. Following peripheral injury, the spinal cord sensitizes. A sign of spinal sensitization is the hyper-reflexia which develops shortly after injury and can be detected in the isolated spinal cord as a "memory of pain." In this context, it is easy to understand that many analgesic compounds target spinally located sites of action to attain analgesia. In vitro isolated spinal cord preparations have been used for a number of years, and experience on the effects of compounds of diverse pharmacological families on spinal function has accumulated. Recently, we have proposed that the detailed study of spinal segmental reflexes in vitro may produce data relevant to the evaluation of the analgesic potential of novel compounds. In this review, we describe the main features of segmental reflexes obtained in vitro and discuss the effects of compounds of diverse chemical nature and pharmacological properties on such reflexes. Our aim was to compare the different profiles of action of the compounds on segmental reflexes in order to extract clues that may be helpful for pharmacological characterization of novel analgesics. © 2015 John Wiley & Sons Ltd.

Association of insurance status and spinal fusion usage in the United States during two decades.

PubMed

John, Jason; Mirahmadizadeh, Alireza; Seifi, Ali

2018-05-01

This study examined the distribution of spinal fusion usage among payer groups in the United States. Using the National Inpatient Sample (NIS) database, total discharges, length of stay, and mean hospital charges of patients who underwent spinal fusion from 1997 to 2014 in the United States were determined and analyzed. 5,715,625 total discharges with spinal fusion were reported. Among them, 2,875,188 (50.3%) were covered by private insurance, 1,710,182 by Medicare (29.9%), 342,638 (6.0%) by Medicaid, and 91,990 (1.6%) were uninsured. A statistically significant increase in spinal fusion usage occurred within each payer group over the study period (P < 0.001). For every year of the study period, private insurance patients had the most number and uninsured patients had the least number of total discharges with spinal fusion. Furthermore, annual growth in spinal fusion usage was greatest among private insurance patients, and smallest among uninsured patients. Total discharges with spinal fusion increased significantly across all payer groups between 1997 and 2014, but not equally. Further inquiry is indicated to determine the etiology of spinal fusion usage discrepancies between payer groups. Copyright © 2018 Elsevier Ltd. All rights reserved.

Electroencephalographic evoked pain response is suppressed by spinal cord stimulation in complex regional pain syndrome: a case report.

PubMed

Hylands-White, Nicholas; Duarte, Rui V; Beeson, Paul; Mayhew, Stephen D; Raphael, Jon H

2016-12-01

Pain is a subjective response that limits assessment. The purpose of this case report was to explore how the objectivity of the electroencephalographic response to thermal stimuli would be affected by concurrent spinal cord stimulation. A patient had been implanted with a spinal cord stimulator for the management of complex regional pain syndrome of both hands for 8 years. Following ethical approval and written informed consent we induced thermal stimuli using the Medoc PATHWAY Pain & Sensory Evaluation System on the right hand of the patient with the spinal cord stimulator switched off and with the spinal cord stimulator switched on. The patient reported a clinically significant reduction in thermal induced pain using the numerical rating scale (71.4 % reduction) with spinal cord stimulator switched on. Analysis of electroencephalogram recordings indicated the occurrence of contact heat evoked potentials (N2-P2) with spinal cord stimulator off, but not with spinal cord stimulator on. This case report suggests that thermal pain can be reduced in complex regional pain syndrome patients with the use of spinal cord stimulation and offers objective validation of the reported outcomes with this treatment.

A novel positive transcriptional feedback loop in midbrain-hindbrain boundary development is revealed through analysis of the zebrafish pax2.1 promoter in transgenic lines.

PubMed

Picker, Alexander; Scholpp, Steffen; Böhli, Heike; Takeda, Hiroyuki; Brand, Michael

2002-07-01

The pax2.1 gene encodes a paired-box transcription factor that is one of the earliest genes to be specifically activated in development of the midbrain and midbrain-hindbrain boundary (MHB), and is required for the development and organizer activity of this territory. To understand how this spatially restricted transcriptional activity of pax2.1 is achieved, we have isolated and characterized the pax2.1-promoter using a lacZ and a GFP reporter gene in transient injection assays and transgenic lines. Stable transgenic expression of this reporter gene shows that a 5.3-kb fragment of the 5' region contains most, but not all, elements required for driving pax2.1 expression. The expressing tissues include the MHB, hindbrain, spinal cord, ear and pronephros. Transgene activation in the pronephros and developing ear suggests that these pax2.1-expressing tissues are composed of independently regulated subdomains. In addition, ectopic but spatially restricted activation of the reporter genes in rhombomeres 3 and 5 and in the forebrain, which do not normally express endogenous pax2.1, demonstrates the importance of negative regulation of pax2.1. Comparison of transgene expression in wild-type and homozygous pax2.1 mutant no isthmus (noi) embryos reveals that the transgene contains control element(s) for a novel, positive transcriptional feedback loop in MHB development. Transcription of endogenous pax2.1 at the MHB is known to be initially Pax2.1 independent, during activation in late gastrulation. In contrast, transgene expression requires the endogenous Pax2.1 function. Transplantations, mRNA injections and morpholino knock-down experiments show that this feedback regulation of pax2.1 transcription occurs cell-autonomously, and that it requires eng2 and eng3 as known targets for Pax2.1 regulation. We suggest that this novel feedback loop may allow continuation of pax2.1 expression, and hence development of the MHB organizer, to become independent of the patterning machinery of the gastrula embryo.

Integrating Brain and Biomechanical Models—A New Paradigm for Understanding Neuro-muscular Control

PubMed Central

James, Sebastian S.; Papapavlou, Chris; Blenkinsop, Alexander; Cope, Alexander J.; Anderson, Sean R.; Moustakas, Konstantinos; Gurney, Kevin N.

2018-01-01

To date, realistic models of how the central nervous system governs behavior have been restricted in scope to the brain, brainstem or spinal column, as if these existed as disembodied organs. Further, the model is often exercised in relation to an in vivo physiological experiment with input comprising an impulse, a periodic signal or constant activation, and output as a pattern of neural activity in one or more neural populations. Any link to behavior is inferred only indirectly via these activity patterns. We argue that to discover the principles of operation of neural systems, it is necessary to express their behavior in terms of physical movements of a realistic motor system, and to supply inputs that mimic sensory experience. To do this with confidence, we must connect our brain models to neuro-muscular models and provide relevant visual and proprioceptive feedback signals, thereby closing the loop of the simulation. This paper describes an effort to develop just such an integrated brain and biomechanical system using a number of pre-existing models. It describes a model of the saccadic oculomotor system incorporating a neuromuscular model of the eye and its six extraocular muscles. The position of the eye determines how illumination of a retinotopic input population projects information about the location of a saccade target into the system. A pre-existing saccadic burst generator model was incorporated into the system, which generated motoneuron activity patterns suitable for driving the biomechanical eye. The model was demonstrated to make accurate saccades to a target luminance under a set of environmental constraints. Challenges encountered in the development of this model showed the importance of this integrated modeling approach. Thus, we exposed shortcomings in individual model components which were only apparent when these were supplied with the more plausible inputs available in a closed loop design. Consequently we were able to suggest missing functionality which the system would require to reproduce more realistic behavior. The construction of such closed-loop animal models constitutes a new paradigm of computational neurobehavior and promises a more thoroughgoing approach to our understanding of the brain's function as a controller for movement and behavior. PMID:29467606

A Game of Space Telephone

NASA Technical Reports Server (NTRS)

2005-01-01

This image shows NASA's Deep Impact impactor spacecraft while it was being built at Ball Aerospace & Technologies Corporation, Boulder, Colo. On July 2, at 10:52 p.m. Pacific time (1:52 a.m. Eastern time, July 3), the impactor will be released from Deep Impact's flyby spacecraft. One day later, it will collide with Tempel 1. The impactor cannot directly talk to Earth, so it will communicate via the flyby spacecraft during its final day.

The two spacecraft communicate at 'S-band' frequency. The impactor's S-band antenna is the rectangle-shaped object seen on the top of the impactor in this image.

Makgadikgadi Salt Pan, Botswana, Africa

NASA Image and Video Library

1992-01-19

STS054-151-015 (13-19 Jan 1993) --- The Makgadikgadi Salt Pan is one of the largest features in Botswana visible from space. Any water that spills out of the Okavango Swamplands flows down to the Makgadikgadi where it evaporates. An ancient beach line can be seen as a smooth line around the west (left) side of the Pan. Orapa diamond mine can be detected due south of the pan as a small rectangle. The large geological feature known as the Great Dike of Zimbabwe can be seen far right. This large panorama shows clouds in southern Angola, Zambia and Zimbabwe in the distance.

Vibration stress relief of DH 36 rectangle welded plates

NASA Astrophysics Data System (ADS)

Li, Shuqi; Fang, Hongyuan

2018-03-01

Vibration stress relief (VSR) is widely used in reducing residual stress in welded structures. However, the effectiveness of this method is still instable in some circumstance. In this study, a covert negative treatment phenomenon was investigated, i.e. natural frequency of welded structures decreased after VSR but residual stress in one direction increased. When the alteration of natural frequency after VSR is significant, the residual stresses in both the longitudinal and transversal directions shall decrease. Otherwise, residual stresses may increase on one direction. Thus, sufficient power shall be applied to the welded structures to avoid negative results.

Rotation in Free Fall of Rectangular Wings of Elongated Shape

NASA Technical Reports Server (NTRS)

Dupleich, Paul

1949-01-01

The present report of Mr. Dupleich is the summary of a very extensive experimental study of the well-known mechanical phenomenon: the rotation in free fall (* air, for instance) of more or less elongated rectangles cut out of paper or pasteboard. This phenomenon, the conditions for existence of which depend chiefly on the elongated of the small plate and its weight per unit area, is essentially an aerodynamic phenomenon and as such, raises questions of a certain interest to our department.We believe that the modern concepts of the mechanics of fluids do not have the range attributed to them.

Comment on "Exact solution of resonant modes in a rectangular resonator".

PubMed

Gutiérrez-Vega, Julio C; Bandres, Miguel A

2006-08-15

We comment on the recent Letter by J. Wu and A. Liu [Opt. Lett. 31, 1720 (2006)] in which an exact scalar solution to the resonant modes and the resonant frequencies in a two-dimensional rectangular microcavity were presented. The analysis is incorrect because (a) the field solutions were imposed to satisfy simultaneously both Dirichlet and Neumann boundary conditions at the four sides of the rectangle, leading to an overdetermined problem, and (b) the modes in the cavity were expanded using an incorrect series ansatz, leading to an expression for the mode fields that does not satisfy the Helmholtz equation.

Magnetic resonance imaging of spinal infection.

PubMed

Tins, Bernhard J; Cassar-Pullicino, Victor N; Lalam, Radhesh K

2007-06-01

This article reviews the pathophysiology of spinal infection and its relevance for imaging. Magnetic resonance imaging (MRI) is the modality with by far the best sensitivity and specificity for spinal infection. The imaging appearances of spinal infection in MRI are outlined, and imaging techniques are discussed. The problems of clinical diagnosis are outlined. There is some emphasis on the MRI differentiation of pyogenic and nonpyogenic infection and on the differential diagnosis of spinal infection centered on the imaging presentation.

Noninvasive Optical Monitoring of Spinal Cord Hemodynamics and Oxygenation after Acute Spinal Cord Injury

DTIC Science & Technology

2017-09-01

oxygen delivery and oxygen consumption . The oxygen portion of the Oxylite probe emits short pulses of blue LED light resulting in a fluorescent...Award Number: W81XWH-16-1-0602 TITLE: Noninvasive Optical Monitoring of Spinal Cord Hemodynamics and Oxygenation after Acute Spinal Cord Injury...COVERED 1 Sep 2016 - 31 Aug 2017 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Noninvasive Optical Monitoring of Spinal Cord Hemodynamics and Oxygenation

Spinal Stiffness in Prone and Upright Postures During 0-1.8 g Induced by Parabolic Flight.

PubMed

Swanenburg, Jaap; Meier, Michael L; Langenfeld, Anke; Schweinhardt, Petra; Humphreys, B Kim

2018-06-01

The purpose of this study was to analyze posterior-to-anterior spinal stiffness in Earth, hyper-, and microgravity conditions during both prone and upright postures. During parabolic flight, the spinal stiffness of the L3 vertebra of a healthy 37-yr-old man was measured in normal Earth gravity (1.0 g), hypergravity (1.8 g), and microgravity (0.0 g) conditions induced in the prone and upright positions. Differences in spinal stiffness were significant across all three gravity conditions in the prone and upright positions. Most effect sizes were large; however, in the upright posture, the effect size between Earth gravity and microgravity was medium. Significant differences in spinal stiffness between the prone and upright positions were found during Earth gravity and hypergravity conditions. No difference was found between the two postures during microgravity conditions. Based on repeated measurements of a single individual, our results showed detectable changes in posterior-to-anterior spinal stiffness. Spinal stiffness increased during microgravity and decreased during hypergravity conditions. In microgravity conditions, posture did not impact spinal stiffness. More data on spinal stiffness in variable gravitational conditions is needed to confirm these results.Swanenburg J, Meier ML, Langenfeld A, Schweinhardt P, Humphreys BK. Spinal stiffness in prone and upright postures during 0-1.8 g induced by parabolic flight. Aerosp Med Hum Perform. 2018; 89(6):563-567.

Spinal cord injury: overview of experimental approaches used to restore locomotor activity.

PubMed

Fakhoury, Marc

2015-01-01

Spinal cord injury affects more than 2.5 million people worldwide and can lead to paraplegia and quadriplegia. Anatomical discontinuity in the spinal cord results in disruption of the impulse conduction that causes temporary or permanent changes in the cord's normal functions. Although axonal regeneration is limited, damage to the spinal cord is often accompanied by spontaneous plasticity and axon regeneration that help improve sensory and motor skills. The recovery process depends mainly on synaptic plasticity in the preexisting circuits and on the formation of new pathways through collateral sprouting into neighboring denervated territories. However, spontaneous recovery after spinal cord injury can go on for several years, and the degree of recovery is very limited. Therefore, the development of new approaches that could accelerate the gain of motor function is of high priority to patients with damaged spinal cord. Although there are no fully restorative treatments for spinal injury, various rehabilitative approaches have been tested in animal models and have reached clinical trials. In this paper, a closer look will be given at the potential therapies that could facilitate axonal regeneration and improve locomotor recovery after injury to the spinal cord. This article highlights the application of several interventions including locomotor training, molecular and cellular treatments, and spinal cord stimulation in the field of rehabilitation research. Studies investigating therapeutic approaches in both animal models and individuals with injured spinal cords will be presented.

Incidental occlusion of anterior spinal artery due to Onyx reflux in embolization of spinal type II arteriovenous malformation.

PubMed

Kim, Joohyun; Lee, Jang-Bo; Cho, Tai-Hyoung; Hur, Junseok W

2017-05-01

Onyx embolization is one of the standard treatments for brain arteriovenous malformations (AVMs) and is a promising method for spinal AVMs as well. Its advantages have been emphasized, and few complications have been reported with Onyx embolization in spinal AVMs. Here, we report an incidental anterior spinal artery (ASA) occlusion due to Onyx reflux during embolization of a spinal type II AVM. A 15-year-old boy presented with weakness in both upper and lower extremities. Magnetic resonance imaging and spinal angiogram revealed a spinal type II AVM with two feeders including the right vertebral artery (VA) and the right deep cervical artery. Onyx embolization was performed gradually from the VA to the deep cervical artery and an unexpected Onyx reflux to the ASA was observed during the latter stage deep cervical artery embolization. Post-operative quadriplegia and low cranial nerves (CN) dysfunction were observed. Rehabilitation treatment was performed and the patient showed marked improvement of neurologic deterioration at 1-year follow-up. Onyx is an effective treatment choice for spinal AVMs. However, due to the small vasculature of the spine compared to the brain, the nidus is rapidly packed with a small amount of Onyx, which allows Onyx reflux to unexpected vessels. Extreme caution is required and dual-lumen balloon catheter could be considered for Onyx embolization in spinal AVMs treatment.

Driving Safety after Spinal Surgery: A Systematic Review

PubMed Central

Alkhalili, Kenan; Hannallah, Jack; Ibeche, Bashar; Bajammal, Sohail; Baco, Abdul Moeen

2017-01-01

This study aimed to assess driving reaction times (DRTs) after spinal surgery to establish a timeframe for safe resumption of driving by the patient postoperatively. The MEDLINE and Google Scholar databases were analyzed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) Statement for clinical studies that investigated changes in DRTs following cervical and lumbar spinal surgery. Changes in DRTs and patients' clinical presentation, pathology, anatomical level affected, number of spinal levels involved, type of intervention, pain level, and driving skills were assessed. The literature search identified 12 studies that investigated postoperative DRTs. Six studies met the inclusion criteria; five studies assessed changes in DRT after lumbar spine surgery and two studies after cervical spina surgery. The spinal procedures were selective nerve root block, anterior cervical discectomy and fusion, and lumbar fusion and/ordecompression. DRTs exhibited variable responses to spinal surgery and depended on the patients' clinical presentation, spinal level involved, and type of procedure performed. The evidence regarding the patients' ability to resume safe driving after spinal surgery is scarce. Normalization of DRT or a return of DRT to pre-spinal intervention level is a widely accepted indicator for safe driving, with variable levels of statistical significance owing to multiple confounding factors. Considerations of the type of spinal intervention, pain level, opioid consumption, and cognitive function should be factored in the assessment of a patient's ability to safely resume driving. PMID:28443178

Driving Safety after Spinal Surgery: A Systematic Review.

PubMed

Alhammoud, Abduljabbar; Alkhalili, Kenan; Hannallah, Jack; Ibeche, Bashar; Bajammal, Sohail; Baco, Abdul Moeen

2017-04-01

This study aimed to assess driving reaction times (DRTs) after spinal surgery to establish a timeframe for safe resumption of driving by the patient postoperatively. The MEDLINE and Google Scholar databases were analyzed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) Statement for clinical studies that investigated changes in DRTs following cervical and lumbar spinal surgery. Changes in DRTs and patients' clinical presentation, pathology, anatomical level affected, number of spinal levels involved, type of intervention, pain level, and driving skills were assessed. The literature search identified 12 studies that investigated postoperative DRTs. Six studies met the inclusion criteria; five studies assessed changes in DRT after lumbar spine surgery and two studies after cervical spina surgery. The spinal procedures were selective nerve root block, anterior cervical discectomy and fusion, and lumbar fusion and/ordecompression. DRTs exhibited variable responses to spinal surgery and depended on the patients' clinical presentation, spinal level involved, and type of procedure performed. The evidence regarding the patients' ability to resume safe driving after spinal surgery is scarce. Normalization of DRT or a return of DRT to pre-spinal intervention level is a widely accepted indicator for safe driving, with variable levels of statistical significance owing to multiple confounding factors. Considerations of the type of spinal intervention, pain level, opioid consumption, and cognitive function should be factored in the assessment of a patient's ability to safely resume driving.

NORADRENERGIC INNERVATION OF THE RAT SPINAL CORD CAUDAL TO A COMPLETE SPINAL CORD TRANSECTION: EFFECTS OF OLFACTORY ENSHEATHING GLIA

PubMed Central

Takeoka, Aya; Kubasak, Marc D.; Zhong, Hui; Kaplan, Jennifer; Roy, Roland R.; Phelps, Patricia E.

2010-01-01

Transplantation of olfactory bulb-derived olfactory ensheathing glia (OEG) combined with step training improves hindlimb locomotion in adult rats with a complete spinal cord transection. Spinal cord injury studies use the presence of noradrenergic (NA) axons caudal to the injury site as evidence of axonal regeneration and we previously found more NA axons just caudal to the transection in OEG- than media-injected spinal rats. We therefore hypothesized that OEG transplantation promotes descending coeruleospinal regeneration that contributes to the recovery of hindlimb locomotion. Now we report that NA axons are present throughout the caudal stump of both media- and OEG-injected spinal rats and they enter the spinal cord from the periphery via dorsal and ventral roots and along large penetrating blood vessels. These results indicate that the presence of NA fibers in the caudal spinal cord is not a reliable indicator of coeruleospinal regeneration. We then asked if NA axons appose cholinergic neurons associated with motor functions, i.e., central canal cluster and partition cells (active during fictive locomotion) and somatic motor neurons (SMNs). We found more NA varicosities adjacent to central canal cluster cells, partition cells, and SMNs in the lumbar enlargement of OEG- than media-injected rats. As non-synaptic release of NA is common in the spinal cord, more associations between NA varicosities and motor-associated cholinergic neurons in the lumbar spinal cord may contribute to the improved treadmill stepping observed in OEG-injected spinal rats. This effect could be mediated through direct association with SMNs and/or indirectly via cholinergic interneurons. PMID:20025875

Effect of ramosetron on shivering during spinal anesthesia

PubMed Central

Kim, Min Soo; Kim, Dong Won; Woo, Seung-Hoon; Yon, Jun Heum

2010-01-01

Background Shivering associated with spinal anesthesia is uncomfortable and may interfere with monitoring. The aim of this study is to evaluate the effect of ramosetron, a serotonin-3 receptor antagonist, on the prevention of shivering during spinal anesthesia. Methods We enrolled 52 patients who were ASA I or II and who had undergone knee arthroscopy under spinal anesthesia. Warmed (37°) lactated Ringer's solution was infused over 15 minutes before spinal anesthesia. Patients were randomly allocated to a control group (group S, N = 26) or study group (group R, N = 26). Spinal anesthesia was performed with a 25-G Quincke-type spinal needle between the lumbar 3-4 interspace with 2.2 ml 0.5% hyperbaric bupivacaine. For patients allocated in groups S and R, 2 ml 0.9% saline and 0.3 mg ramosetron, respectively, was intravenously injected immediately before intrathecal injection at identical times. Shivering and spinal block levels were assessed immediately after the completion of subarachnoid injection, as well as 5, 10, 15, 20, 25, 30, 60, and 120 minutes after spinal anesthesia. Systolic and diastolic blood pressures, heart rate, and peripheral oxygen saturation were also recorded. Core temperatures were measured by tympanic thermometer and recorded before and during spinal anesthesia at 30-minute intervals. Results Shivering was observed in 2 patients in group R and 9 patients in group S (P = 0.038, odds ratio = 6.14, 95% C.I. = 1.08-65.5). The difference in core temperature between the groups was not significant. Conclusions Compared to control, ramosetron is an effective way to prevent shivering during spinal anesthesia. PMID:20498774

Clinical, magnetic resonance imaging, and histopathologic findings in 6 dogs with surgically resected extraparenchymal spinal cord hematomas.

PubMed

Hague, D W; Joslyn, S; Bush, W W; Glass, E N; Durham, A C

2015-01-01

Extraparenchymal spinal cord hematoma has been described in veterinary medicine in association with neoplasia, intervertebral disk disease, and snake envenomation. There are rare reports of spontaneous extraparenchymal spinal cord hematoma formation with no known cause in human medicine. Multiple cases of spontaneous extraparenchymal spinal cord hematoma have not been described previously in veterinary medicine. To describe the signalment, clinical findings, magnetic resonance imaging (MRI) features, and surgical outcomes in histopathologically confirmed extraparenchymal spinal cord hematomas in dogs with no identified underlying etiology. Six dogs had MRI of the spinal cord, decompressive spinal surgery, and histopathologic confirmation of extraparenchymal spinal cord hematoma not associated with an underlying cause. Multi-institutional retrospective study. Six patients had spontaneous extraparenchymal spinal cord hematoma formation. MRI showed normal signal within the spinal cord parenchyma in all patients. All hematomas had T2-weighted hyperintensity and the majority (5/6) had no contrast enhancement. All dogs underwent surgical decompression and most patients (5/6) returned to normal or near normal neurologic function postoperatively. Follow-up of the patients (ranging between 921 and 1,446 days) showed no progression of neurologic clinical signs or any conditions associated with increased bleeding tendency. Before surgery and histopathology confirming extraparenchymal hematoma, the primary differential in most cases was neoplasia, based on the MRI findings. This retrospective study reminds clinicians of the importance of the combination of advanced imaging combined with histopathologic diagnosis. The prognosis for spontaneous spinal cord extraparenchymal hematoma with surgical decompression appears to be favorable in most cases. Copyright © 2015 by the American College of Veterinary Internal Medicine.

Spinal Health during Unloading and Reloading Associated with Spaceflight

PubMed Central

Green, David A.; Scott, Jonathan P. R.

2018-01-01

Spinal elongation and back pain are recognized effects of exposure to microgravity, however, spinal health has received relatively little attention. This changed with the report of an increased risk of post-flight intervertebral disc (IVD) herniation and subsequent identification of spinal pathophysiology in some astronauts post-flight. Ground-based analogs, particularly bed rest, suggest that a loss of spinal curvature and IVD swelling may be factors contributing to unloading-induced spinal elongation. In flight, trunk muscle atrophy, in particular multifidus, may precipitate lumbar curvature loss and reduced spinal stability, but in-flight (ultrasound) and pre- and post-flight (MRI) imaging have yet to detect significant IVD changes. Current International Space Station missions involve short periods of moderate-to-high spinal (axial) loading during running and resistance exercise, superimposed upon a background of prolonged unloading (microgravity). Axial loading acting on a dysfunctional spine, weakened by anatomical changes and local muscle atrophy, might increase the risk of damage/injury. Alternatively, regular loading may be beneficial. Spinal pathology has been identified in-flight, but there are few contemporary reports of in-flight back injury and no recent studies of post-flight back injury incidence. Accurate routine in-flight stature measurements, in- and post-flight imaging, and tracking of pain and injury (herniation) for at least 2 years post-flight is thus warranted. These should be complemented by ground-based studies, in particular hyper buoyancy floatation (HBF) a novel analog of spinal unloading, in order to elucidate the mechanisms and risk of spinal injury, and to evaluate countermeasures for exploration where injury could be mission critical. PMID:29403389

Degenerative spinal disease in large felids.

PubMed

Kolmstetter, C; Munson, L; Ramsay, E C

2000-03-01

Degenerative spinal disorders, including intervertebral disc disease and spondylosis, seldom occur in domestic cats. In contrast, a retrospective study of 13 lions (Panthera leo), 16 tigers (Panthera tigris), 4 leopards (Panthera pardis), 1 snow leopard (Panthera uncia), and 3 jaguars (Panthera onca) from the Knoxville Zoo that died or were euthanatized from 1976 to 1996 indicated that degenerative spinal disease is an important problem in large nondomestic felids. The medical record, radiographic data, and the necropsy report of each animal were examined for evidence of intervertebral disc disease or spondylosis. Eight (three lions, four tigers, and one leopard) animals were diagnosed with degenerative spinal disease. Clinical signs included progressively decreased activity, moderate to severe rear limb muscle atrophy, chronic intermittent rear limb paresis, and ataxia. The age at onset of clinical signs was 10-19 yr (median = 18 yr). Radiographic evaluation of the spinal column was useful in assessing the severity of spinal lesions, and results were correlated with necropsy findings. Lesions were frequently multifocal, included intervertebral disc mineralization or herniation with collapsed intervertebral disc spaces, and were most common in the lumbar area but also involved cervical and thoracic vertebrae. Marked spondylosis was present in the cats with intervertebral disc disease, presumably subsequent to vertebral instability. Six of the animals' spinal cords were examined histologically, and five had acute or chronic damage to the spinal cord secondary to disc protrusion. Spinal disease should be suspected in geriatric large felids with decreased appetite or activity. Radiographic evaluation of the spinal column is the most useful method to assess the type and severity of spinal lesions.

Retraining the injured spinal cord

NASA Technical Reports Server (NTRS)

Edgerton, V. R.; Leon, R. D.; Harkema, S. J.; Hodgson, J. A.; London, N.; Reinkensmeyer, D. J.; Roy, R. R.; Talmadge, R. J.; Tillakaratne, N. J.; Timoszyk, W.;

Spinal astrocyte gap junctions contribute to oxaliplatin-induced mechanical hypersensitivity.

PubMed

Yoon, Seo-Yeon; Robinson, Caleb R; Zhang, Haijun; Dougherty, Patrick M

2013-02-01

Spinal glial cells contribute to the development of many types of inflammatory and neuropathic pain. Here the contribution of spinal astrocytes and astrocyte gap junctions to oxaliplatin-induced mechanical hypersensitivity was explored. The expression of glial fibrillary acidic protein (GFAP) in spinal dorsal horn was significantly increased at day 7 but recovered at day 14 after oxaliplatin treatment, suggesting a transient activation of spinal astrocytes by chemotherapy. Astrocyte-specific gap junction protein connexin 43 (Cx43) was significantly increased in dorsal horn at both day 7 and day 14 following chemotherapy, but neuronal (connexin 36 [Cx36]) and oligodendrocyte (connexin 32 [Cx32]) gap junction proteins did not show any change. Blockade of astrocyte gap junction with carbenoxolone (CBX) prevented oxaliplatin-induced mechanical hypersensitivity in a dose-dependent manner and the increase of spinal GFAP expression, but had no effect once the mechanical hypersensitivity induced by oxaliplatin had fully developed. These results suggest that oxaliplatin chemotherapy induces the activation of spinal astrocytes and this is accompanied by increased expression of astrocyte-astrocyte gap junction connections via Cx43. These alterations in spinal astrocytes appear to contribute to the induction but not the maintenance of oxaliplatin-induced mechanical hypersensitivity. Combined, these results suggest that targeting spinal astrocyte/astrocyte-specific gap junction could be a new therapeutic strategy to prevent oxaliplatin-induced neuropathy. Spinal astrocytes but not microglia were recently shown to be recruited in paclitaxel-related chemoneuropathy. Here, spinal astrocyte gap junctions are shown to play an important role in the induction of oxaliplatin neuropathy. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

Automated extraction method for the center line of spinal canal and its application to the spinal curvature quantification in torso X-ray CT images

NASA Astrophysics Data System (ADS)

Hayashi, Tatsuro; Zhou, Xiangrong; Chen, Huayue; Hara, Takeshi; Miyamoto, Kei; Kobayashi, Tatsunori; Yokoyama, Ryujiro; Kanematsu, Masayuki; Hoshi, Hiroaki; Fujita, Hiroshi

2010-03-01

X-ray CT images have been widely used in clinical routine in recent years. CT images scanned by a modern CT scanner can show the details of various organs and tissues. This means various organs and tissues can be simultaneously interpreted on CT images. However, CT image interpretation requires a lot of time and energy. Therefore, support for interpreting CT images based on image-processing techniques is expected. The interpretation of the spinal curvature is important for clinicians because spinal curvature is associated with various spinal disorders. We propose a quantification scheme of the spinal curvature based on the center line of spinal canal on CT images. The proposed scheme consists of four steps: (1) Automated extraction of the skeletal region based on CT number thresholding. (2) Automated extraction of the center line of spinal canal. (3) Generation of the median plane image of spine, which is reformatted based on the spinal canal. (4) Quantification of the spinal curvature. The proposed scheme was applied to 10 cases, and compared with the Cobb angle that is commonly used by clinicians. We found that a high-correlation (for the 95% confidence interval, lumbar lordosis: 0.81-0.99) between values obtained by the proposed (vector) method and Cobb angle. Also, the proposed method can provide the reproducible result (inter- and intra-observer variability: within 2°). These experimental results suggested a possibility that the proposed method was efficient for quantifying the spinal curvature on CT images.

Cytoarchitecture of the spinal cord of the postnatal (P4) mouse.

PubMed

Sengul, Gulgun; Puchalski, Ralph B; Watson, Charles

2012-05-01

Interpretation of the new wealth of gene expression and molecular mechanisms in the developing mouse spinal cord requires an accurate anatomical base on which data can be mapped. Therefore, we have assembled a spinal cord atlas of the P4 mouse to facilitate direct comparison with the adult specimens and to contribute to studies of the development of the mouse spinal cord. This study presents the anatomy of the spinal cord of the P4 C57Bl/6J mouse using Nissl and acetyl cholinesterase-stained sections. It includes a detailed map of the laminar organization of selected spinal cord segments and a description of named cell groups of the spinal cord such as the central cervical (CeCv), lateral spinal nucleus, lateral cervical, and dorsal nuclei. The motor neuron groups have also been identified according to the muscle groups they are likely to supply. General features of Rexed's laminae of the P4 spinal cord showed similarities to that of the adult (P56). However, certain differences were observed with regard to the extent of laminae and location of certain cell groups, such as the dorsal nucleus having a more dispersed structure and a more ventral and medial position or the CeCv being located in the medial part of lamina 5 in contrast to the adult where it is located in lamina 7. Motor neuron pools appeared to be more tightly packed in the P4 spinal cord. The dorsal horn was relatively larger and there was more white matter in the P56 spinal cord. Copyright © 2012 Wiley Periodicals, Inc.

Spinal Health during Unloading and Reloading Associated with Spaceflight.

PubMed

Green, David A; Scott, Jonathan P R

2017-01-01

Spinal elongation and back pain are recognized effects of exposure to microgravity, however, spinal health has received relatively little attention. This changed with the report of an increased risk of post-flight intervertebral disc (IVD) herniation and subsequent identification of spinal pathophysiology in some astronauts post-flight. Ground-based analogs, particularly bed rest, suggest that a loss of spinal curvature and IVD swelling may be factors contributing to unloading-induced spinal elongation. In flight, trunk muscle atrophy, in particular multifidus , may precipitate lumbar curvature loss and reduced spinal stability, but in-flight (ultrasound) and pre- and post-flight (MRI) imaging have yet to detect significant IVD changes. Current International Space Station missions involve short periods of moderate-to-high spinal (axial) loading during running and resistance exercise, superimposed upon a background of prolonged unloading (microgravity). Axial loading acting on a dysfunctional spine, weakened by anatomical changes and local muscle atrophy, might increase the risk of damage/injury. Alternatively, regular loading may be beneficial. Spinal pathology has been identified in-flight, but there are few contemporary reports of in-flight back injury and no recent studies of post-flight back injury incidence. Accurate routine in-flight stature measurements, in- and post-flight imaging, and tracking of pain and injury (herniation) for at least 2 years post-flight is thus warranted. These should be complemented by ground-based studies, in particular hyper buoyancy floatation (HBF) a novel analog of spinal unloading, in order to elucidate the mechanisms and risk of spinal injury, and to evaluate countermeasures for exploration where injury could be mission critical.

21 CFR 882.5850 - Implanted spinal cord stimulator for bladder evacuation.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Implanted spinal cord stimulator for bladder evacuation. 882.5850 Section 882.5850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND....5850 Implanted spinal cord stimulator for bladder evacuation. (a) Identification. An implanted spinal...

21 CFR 880.2500 - Spinal fluid manometer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Spinal fluid manometer. 880.2500 Section 880.2500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Devices § 880.2500 Spinal fluid manometer. (a) Identification. A spinal fluid manometer is a device used...

21 CFR 882.5850 - Implanted spinal cord stimulator for bladder evacuation.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implanted spinal cord stimulator for bladder evacuation. 882.5850 Section 882.5850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND....5850 Implanted spinal cord stimulator for bladder evacuation. (a) Identification. An implanted spinal...

21 CFR 880.2460 - Electrically powered spinal fluid pressure monitor.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrically powered spinal fluid pressure monitor... Personal Use Monitoring Devices § 880.2460 Electrically powered spinal fluid pressure monitor. (a) Identification. An electrically powered spinal fluid pressure monitor is an electrically powered device used to...

Spinal infections: clinical and imaging features.

PubMed

Arbelaez, Andres; Restrepo, Feliza; Castillo, Mauricio

2014-10-01

Spinal infections represent a group of rare conditions affecting vertebral bodies, intervertebral discs, paraspinal soft tissues, epidural space, meninges, and spinal cord. The causal factors, clinical presentations, and imaging features are a challenge because the difficulty to differentiate them from other conditions, such as degenerative and inflammatory disorders and spinal neoplasm. They require early recognition because delay diagnosis, imaging, and intervention may have devastating consequences especially in children and the elderly. This article reviews the most common spinal infections, their pathophysiologic, clinical manifestation, and their imaging findings.

Combined Effects of Acrobatic Exercise and Magnetic Stimulation on the Functional Recovery after Spinal Cord Lesions

PubMed Central

Wieraszko, Andrzej

2008-01-01

Abstract The objective of the study was to determine whether physical exercise combined with epidural spinal cord magnetic stimulation could improve recovery after injury of the spinal cord. Spinal cord lesioning in mice resulted in reduced locomotor function and negatively affected the muscle strength tested in vitro. Acrobatic exercise attenuated the behavioral effects of spinal cord injury. The exposure to magnetic fields facilitated further this improvement. The progress in behavioral recovery was correlated with reduced muscle degeneration and enhanced muscle contraction. The acrobatic exercise combined with stimulation with magnetic fields significantly facilitates behavioral recovery and muscle physiology in mice following spinal cord injury. PMID:18986227

Exploration of Spinal Cord Aging-Related Proteins Using a Proteomics Approach.

PubMed

Kamiya, Koshiro; Furuya, Takeo; Hashimoto, Masayuki; Mannoji, Chikato; Inada, Taigo; Ota, Mitsutoshi; Maki, Satoshi; Ijima, Yasushi; Saito, Junya; Kitamura, Mitsuhiro; Ohtori, Seiji; Orita, Sumihisa; Inage, Kazuhide; Yamazaki, Masashi; Koda, Masao

2017-01-01

How aging affects the spinal cord at a molecular level is unclear. The aim of this study was to explore spinal cord aging-related proteins that may be involved in pathological mechanisms of age-related changes in the spinal cord. Spinal cords of 2-year-old and 8-week-old female Sprague-Dawley rats were dissected from the animals. Protein samples were subjected to 2-dimentional polyacrylamide gel electrophoresis followed by mass spectrometry. Screened proteins were further investigated with immunohistochemistry and Western blotting. Among the screened proteins, we selected α-crystallin B-subunit (αB-crystallin) and peripherin for further investigation because these proteins were previously reported to be related to central nervous system pathologies. Immunohistochemistry and Western blotting revealed significant upregulation of αB-crystallin and peripherin expression in aged rat spinal cord. Further exploration is needed to elucidate the precise mechanism and potential role of these upregulated proteins in spinal cord aging processes.

Cortex-dependent recovery of unassisted hindlimb locomotion after complete spinal cord injury in adult rats

PubMed Central

Manohar, Anitha; Foffani, Guglielmo; Ganzer, Patrick D; Bethea, John R; Moxon, Karen A

2017-01-01

After paralyzing spinal cord injury the adult nervous system has little ability to ‘heal’ spinal connections, and it is assumed to be unable to develop extra-spinal recovery strategies to bypass the lesion. We challenge this assumption, showing that completely spinalized adult rats can recover unassisted hindlimb weight support and locomotion without explicit spinal transmission of motor commands through the lesion. This is achieved with combinations of pharmacological and physical therapies that maximize cortical reorganization, inducing an expansion of trunk motor cortex and forepaw sensory cortex into the deafferented hindlimb cortex, associated with sprouting of corticospinal axons. Lesioning the reorganized cortex reverses the recovery. Adult rats can thus develop a novel cortical sensorimotor circuit that bypasses the lesion, probably through biomechanical coupling, to partly recover unassisted hindlimb locomotion after complete spinal cord injury. DOI: http://dx.doi.org/10.7554/eLife.23532.001 PMID:28661400

Ergonomics intervention on an alternative design of a spinal board.

PubMed

Zadry, Hilma Raimona; Susanti, Lusi; Rahmayanti, Dina

2017-09-01

A spinal board is the evacuation tool of first aid to help the injured spinal cord. The existing spinal board has several weaknesses, both in terms of user comfort and the effectiveness and efficiency of the evacuation process. This study designs an ergonomic spinal board using the quality function deployment approach. A preliminary survey was conducted through direct observation and interviews with volunteers from the Indonesian Red Cross. Data gathered were translated into a questionnaire and answered by 47 participants in West Sumatra. The results indicate that the selection of materials, the application of strap systems as well as the addition of features are very important in designing an ergonomic spinal board. The data were used in designing an ergonomic spinal board. The use of anthropometric data ensures that this product can accommodate safety and comfort when immobilized, as well as the flexibility and speed of the rescue evacuation process.

[Diagnostic imaging of spinal diseases].

PubMed

Miyasaka, Kazuo

2005-11-01

With the advent of magnetic resonance imaging, diagnostic accuracy of spinal disorders has been much improved regarding their localization and histological prediction. The location of herniated disc materials is well appreciated on MR images without using contrast materials. MRI can predict the posterior longitudinal ligament is perforated or not. Kinematics of the spinal axis and CSF flow movement is evaluated on MRI with fast imaging. MR angiography with 3D reconstruction depicts the Adamkiewicz's artery and anterior spinal artery. Neuritis and neuropathy can be diagnosed by post-contrast T1 weighted image since inflammatory nerves are thick and enhance. Some intramedullary deseases tend to involve the peripheral area of the spinal cord; others are central. Edema extends longitudinally within the spinal cord by sparing the peripheral margin of the spinal cord and it is well appreciated with the T2- and proton- weighted images. The lateral and posterior funiculi are more frequently involved in multiple sclerosis.

Recurrent ‘universal tumour’ of the spinal cord

PubMed Central

O'Grady, John; Kaliaperumal, Chandrasekaran; O'Sullivan, Michael

2012-01-01

Lipoma is popularly known as the ‘universal tumour’ because of its ubiquitous presence anywhere in the body. This is the first documented case of recurrent thoracic spinal cord intramedullary lipoma in a 44-year-old man, with a background of spinal dysraphism, which recurred 15 years after initial surgery. He was followed up every 2 years and currently presented with an 8-month history of progressive weakness in his lower limbs. An MRI of the spine confirmed recurrence of lipoma. He underwent redo laminectomy and partial resection and spinal cord decompression with duroplasty. Lipoma, although a low-grade tumour, can cause significant neurological deficits because of its location. Surgical exploration and removal of lipoma is recommended. However, to preserve the functionality of the spinal cord, one may resort to partial resection and aim for spinal cord decompression. The literature on spinal cord lipoma is reviewed and the aetiopathogenesis of this rare occurrence is described. PMID:22675149

Spinal Cord Lesions in Congenital Toxoplasmosis Demonstrated with Neuroimaging, Including Their Successful Treatment in an Adult.

PubMed

Burrowes, Delilah; Boyer, Kenneth; Swisher, Charles N; Noble, A Gwendolyn; Sautter, Mari; Heydemann, Peter; Rabiah, Peter; Lee, Daniel; McLeod, Rima

2012-03-01

Neuroimaging studies for persons in the National Collaborative Chicago-Based Congenital Toxoplasmosis Study (NCCCTS) with symptoms and signs referable to the spinal cord were reviewed. Three infants had symptomatic spinal cord lesions, another infant a Chiari malformation, and another infant a symptomatic peri-spinal cord lipoma. One patient had an unusual history of prolonged spinal cord symptoms presenting in middle age. Neuroimaging was used to establish her diagnosis and response to treatment. This 43 year-old woman with congenital toxoplasmosis developed progressive leg spasticity, weakness, numbness, difficulty walking, and decreased visual acuity and color vision without documented re-activation of her chorioretinal disease. At 52 years of age, spinal cord lesions in locations correlating with her symptoms and optic atrophy were diagnosed with 3 Tesla MRI scan. Treatment with pyrimethamine and sulfadiazine decreased her neurologic symptoms, improved her neurologic examination, and resolved her enhancing spinal cord lesions seen on MRI.

Sensitivity of MRI of the spine compared with CT myelography in orthostatic headache with CSF leak.

PubMed

Starling, Amaal; Hernandez, Fatima; Hoxworth, Joseph M; Trentman, Terrence; Halker, Rashmi; Vargas, Bert B; Hastriter, Eric; Dodick, David

2013-11-12

To investigate the sensitivity of MRI of the spine compared with CT myelography (CTM) in detecting CSF leaks. Between July 1998 and October 2010, 12 patients with orthostatic headache and a CTM-confirmed spinal CSF leak underwent an MRI of the spine with and without contrast. Using CTM as the gold standard, we retrospectively investigated the sensitivity of spinal MRI in detecting a CSF leak. Eleven of 12 patients with a CSF leak documented by CTM also had extradural fluid collections on spinal MRI (sensitivity 91.7%). Six patients with extradural fluid collections on spinal MRI also had spinal dural enhancement. When compared with the gold standard of CTM, MRI of the spine appears to be a sensitive and less invasive imaging modality for detecting a spinal CSF leak, suggesting that MRI of the spine should be the imaging modality of first choice for the detection of spinal CSF leaks.

Are there endogenous stem cells in the spinal cord?

PubMed

Ferrucci, Michela; Ryskalin, Larisa; Busceti, Carla L; Gaglione, Anderson; Biagioni, Francesca; Fornai, Francesco

2017-12-01

Neural progenitor cells (NPC) represent the stem-like niche of the central nervous system that maintains a regenerative potential also in the adult life. Despite NPC in the brain are well documented, the presence of NPC in the spinal cord has been controversial for a long time. This is due to a scarce activity of NPC within spinal cord, which also makes difficult their identification. The present review recapitulates the main experimental studies, which provided evidence for the occurrence of NPC within spinal cord, with a special emphasis on spinal cord injury and amyotrophic lateral sclerosis. By using experimental models, here we analyse the site-specificity, the phenotype and the main triggers of spinal cord NPC. Moreover, data are reported on the effect of specific neurogenic stimuli on these spinal cord NPC in an effort to comprehend the endogenous neurogenic potential of this stem cell niche.

Reduce, reuse, recycle - Developmental signals in spinal cord regeneration.

PubMed

Cardozo, Marcos Julian; Mysiak, Karolina S; Becker, Thomas; Becker, Catherina G

2017-12-01

Anamniotes, fishes and amphibians, have the capacity to regenerate spinal cord tissue after injury, generating new neurons that mature and integrate into the spinal circuitry. Elucidating the molecular signals that promote this regeneration is a fundamental question in regeneration research. Model systems, such as salamanders and larval and adult zebrafish are used to analyse successful regeneration. This shows that many developmental signals, such as Notch, Hedgehog (Hh), Bone Morphogenetic Protein (BMP), Wnt, Fibroblast Growth Factor (FGF), Retinoic Acid (RA) and neurotransmitters are redeployed during regeneration and activate resident spinal progenitor cells. Here we compare the roles of these signals in spinal cord development and regeneration of the much larger and fully patterned adult spinal cord. Understanding how developmental signalling systems are reactivated in successfully regenerating species may ultimately lead to ways to reactivate similar systems in mammalian progenitor cells, which do not show neurogenesis after spinal injury. Copyright © 2017. Published by Elsevier Inc.

21 CFR 882.5880 - Implanted spinal cord stimulator for pain relief.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Implanted spinal cord stimulator for pain relief. 882.5880 Section 882.5880 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Implanted spinal cord stimulator for pain relief. (a) Identification. An implanted spinal cord stimulator...

76 FR 71623 - Agency Information Collection (Spinal Cord Injury Patient Care Survey) Under OMB Review

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-18

... Collection (Spinal Cord Injury Patient Care Survey) Under OMB Review AGENCY: Veterans Benefits Administration... INFORMATION: Title: Spinal Cord Injury Patient Care Survey, VA Form 10-0515. OMB Control Number: OMB Control... 10-0515 will be used to determine spinal cord patients' satisfaction with VA rehabilitation and...

DTI and pathological changes in a rabbit model of radiation injury to the spinal cord after 125I radioactive seed implantation

PubMed Central

Cao, Xia; Fang, Le; Cui, Chuan-yu; Gao, Shi; Wang, Tian-wei

2018-01-01

Excessive radiation exposure may lead to edema of the spinal cord and deterioration of the nervous system. Magnetic resonance imaging can be used to judge and assess the extent of edema and to evaluate pathological changes and thus may be used for the evaluation of spinal cord injuries caused by radiation therapy. Radioactive 125I seeds to irradiate 90% of the spinal cord tissue at doses of 40–100 Gy (D90) were implanted in rabbits at T10 to induce radiation injury, and we evaluated their safety for use in the spinal cord. Diffusion tensor imaging showed that with increased D90, the apparent diffusion coefficient and fractional anisotropy values were increased. Moreover, pathological damage of neurons and microvessels in the gray matter and white matter was aggravated. At 2 months after implantation, obvious pathological injury was visible in the spinal cords of each group. Magnetic resonance diffusion tensor imaging revealed the radiation injury to the spinal cord, and we quantified the degree of spinal cord injury through apparent diffusion coefficient and fractional anisotropy. PMID:29623940

Thoracic Unilateral Spinal Cord Injury After Spinal Anaesthesia for Total Hip Replacement: Fate or Mistake?

PubMed Central

Fabio, Costa; Romualdo, Del Buono; Eugenio, Agrò Felice; Vittoradolfo, Tambone; Massimiliano, Vitali Andrea; Giovanna, Ricci

2017-01-01

Spinal anaesthesia is the most preffered anesthesia technique for total hip replacement, and its complications range from low entity (insignificant) to life threatening. The incidence of neurologic complications after neuraxial anaesthesia is not perfectly clear, although there are several described cases of spinal cord ischaemia. We present a case of unilateral T8–T11 spinal cord ischaemia following L2–L3 spinal anaesthesia for total hip replacement. Magnetic resonance imaging showed a hyperintense T8–T11 signal alteration on the leftside of paramedian spinal cord. A temporal epidemiologic linkage between the damage and the surgery seems to be present. The injury occurred without anatomical proximity between the injury site and the spinal needle entry site. This may be due to multiple contributing factors, each of them is probably not enough to determine the damage by itself; however, acting simultaneously, they could have been responsible for the complication. The result was unpredictable and unavoidable and was caused by unforeseeable circumstances and not by inadequate medical practice. PMID:28439446

Spinal anesthesia in infants: recent developments.

PubMed

Tirmizi, Henna

2015-06-01

Spinal anesthesia has long been described as a well-tolerated and effective means of providing anesthesia for infants undergoing lower abdominal surgery. Now, spinal anesthetics are being used for an increasing variety of surgeries previously believed to require a general anesthetic. This, along with increasing concerns over the neurocognitive effects of general anesthetics on developing brains, suggests that further exploration into this technique and its effects is essential. Exposure to spinal anesthesia in infancy has not shown the same suggestions of neurocognitive detriment as those resulting from general anesthesia. Ultrasound guidance has enhanced spinal technique by providing real-time guidance into the intrathecal space and confirming medication administration location, as well as helping avoid adverse outcomes by identifying aberrant anatomy. Spinal anesthesia provides benefits over general anesthesia, including cardiorespiratory stability, shorter postoperative recovery, and faster return of gastrointestinal function. Early findings of spinal anesthesia exposure in infancy have shown it to have no independent effect on neurocognitive delay as well as to provide sound cardiorespiratory stability. With safer means of administering a spinal anesthetic, such as with ultrasound guidance, it is a readily available and desirable tool for those providing anesthesia to infants.

Effects of pacing-induced myocardial stress and spinal cord stimulation on whole body and cardiac norepinephrine spillover.

PubMed

Norrsell, H; Eliasson, T; Mannheimer, C; Augustinsson, L E; Bergh, C H; Andersson, B; Waagstein, F; Friberg, P

1997-12-01

Spinal cord stimulation has been used in the treatment of intractable angina pectoris since the beginning of the 1980s. This study was designed to investigate whether the documented anti-ischaemic effects of spinal cord stimulation are mediated through a decrease in sympathetic activity. Ten patients with a spinal cord stimulator implanted as anti-anginal treatment were included in the study. Atrial pacing until the patient experienced moderate angina was performed and after 50 min rest the procedure was repeated during spinal cord stimulation. Total body and cardiac norepinephrine spillover was calculated and the former was found to have increased during pacing (47%, P = 0.02). When spinal cord stimulation was applied, total body norepinephrine spillover decreased at a comparable pacing rate (18%, P = 0.02). Cardiac norepinephrine spillover was not affected during the procedure. The results of this study indicate that the anti-ischaemic effect of spinal cord stimulation is not due to reduced cardiac sympathetic activity. However, spinal cord stimulation decreases overall sympathetic activity which may benefit the heart, possibly by reducing oxygen demand.

Virtual endoscopic imaging of the spine.

PubMed

Kotani, Toshiaki; Nagaya, Shigeyuki; Sonoda, Masaru; Akazawa, Tsutomu; Lumawig, Jose Miguel T; Nemoto, Tetsuharu; Koshi, Takana; Kamiya, Koshiro; Hirosawa, Naoya; Minami, Shohei

2012-05-20

Prospective trial of virtual endoscopy in spinal surgery. To investigate the utility of virtual endoscopy of the spine in conjunction with spinal surgery. Several studies have described clinical applications of virtual endoscopy to visualize the inside of the bronchi, paranasal sinus, stomach, small intestine, pancreatic duct, and bile duct, but, to date, no study has described the use of virtual endoscopy in the spine. Virtual endoscopy is a realistic 3-dimensional intraluminal simulation of tubular structures that is generated by postprocessing of computed tomographic data sets. Five patients with spinal disease were selected: 2 patients with degenerative disease, 2 patients with spinal deformity, and 1 patient with spinal injury. Virtual endoscopy software allows an observer to explore the spinal canal with a mouse, using multislice computed tomographic data. Our study found that virtual endoscopy of the spine has advantages compared with standard imaging methods because surgeons can noninvasively explore the spinal canal in all directions. Virtual endoscopy of the spine may be useful to surgeons for diagnosis, preoperative planning, and postoperative assessment by obviating the need to mentally construct a 3-dimensional picture of the spinal canal from 2-dimensional computed tomographic scans.

Minimally Invasive Drainage of a Post-Laminectomy Subfascial Seroma with Cervical Spinal Cord Compression.

PubMed

Kitshoff, Adriaan Mynhardt; Van Goethem, Bart; Cornelis, Ine; Combes, Anais; Dvm, Ingeborgh Polis; Gielen, Ingrid; Vandekerckhove, Peter; de Rooster, Hilde

2016-01-01

A 14 mo old female neutered Doberman pinscher was evaluated for difficulty in rising, a wide based stance, pelvic limb gait abnormalities, and cervical pain of 2 mo duration. Neurologic examination revealed pelvic limb ataxia and cervical spinal hyperesthesia. Spinal reflexes and cranial nerve examination were normal. The pathology was localized to the C1-C5 or C6-T2 spinal cord segments. Computed tomography (CT) findings indicated bony proliferation of the caudal articular processes of C6 and the cranial articular processes of C7, resulting in bilateral dorsolateral spinal cord compression that was more pronounced on the left side. A limited dorsal laminectomy was performed at C6-C7. Due to progressive neurological deterioration, follow-up CT examination was performed 4 days postoperatively. At the level of the laminectomy defect, a subfacial seroma had developed, entering the spinal canal and causing significant spinal cord compression. Under ultrasonographic guidance a closed-suction wound catheter was placed. Drainage of the seroma successfully relieved its compressive effects on the spinal cord and the patient's neurological status improved. CT was a valuable tool in assessing spinal cord compression as a result of a postoperative subfascial seroma. Minimally invasive application of a wound catheter can be successfully used to manage this condition.

Geometric Structure of 3D Spinal Curves: Plane Regions and Connecting Zones

PubMed Central

Berthonnaud, E.; Hilmi, R.; Dimnet, J.

2012-01-01

This paper presents a new study of the geometric structure of 3D spinal curves. The spine is considered as an heterogeneous beam, compound of vertebrae and intervertebral discs. The spine is modeled as a deformable wire along which vertebrae are beads rotating about the wire. 3D spinal curves are compound of plane regions connected together by zones of transition. The 3D spinal curve is uniquely flexed along the plane regions. The angular offsets between adjacent regions are concentrated at level of the middle zones of transition, so illustrating the heterogeneity of the spinal geometric structure. The plane regions along the 3D spinal curve must satisfy two criteria: (i) a criterion of minimum distance between the curve and the regional plane and (ii) a criterion controlling that the curve is continuously plane at the level of the region. The geometric structure of each 3D spinal curve is characterized by the sizes and orientations of regional planes, by the parameters representing flexed regions and by the sizes and functions of zones of transition. Spinal curves of asymptomatic subjects show three plane regions corresponding to spinal curvatures: lumbar, thoracic and cervical curvatures. In some scoliotic spines, four plane regions may be detected. PMID:25031873

Spinal cord stress injury assessment (SCOSIA): clinical applications of mechanical modeling of the spinal cord and brainstem

NASA Astrophysics Data System (ADS)

Wong, Kenneth H.; Choi, Jae; Wilson, William; Berry, Joel; Henderson, Fraser C., Sr.

2009-02-01

Abnormal stretch and strain is a major cause of injury to the spinal cord and brainstem. Such forces can develop from age-related degeneration, congenital malformations, occupational exposure, or trauma such as sporting accidents, whiplash and blast injury. While current imaging technologies provide excellent morphology and anatomy of the spinal cord, there is no validated diagnostic tool to assess mechanical stresses exerted upon the spinal cord and brainstem. Furthermore, there is no current means to correlate these stress patterns with known spinal cord injuries and other clinical metrics such as neurological impairment. We have therefore developed the spinal cord stress injury assessment (SCOSIA) system, which uses imaging and finite element analysis to predict stretch injury. This system was tested on a small cohort of neurosurgery patients. Initial results show that the calculated stress values decreased following surgery, and that this decrease was accompanied by a significant decrease in neurological symptoms. Regression analysis identified modest correlations between stress values and clinical metrics. The strongest correlations were seen with the Brainstem Disability Index (BDI) and the Karnofsky Performance Score (KPS), whereas the weakest correlations were seen with the American Spinal Injury Association (ASIA) scale. SCOSIA therefore shows encouraging initial results and may have wide applicability to trauma and degenerative disease involving the spinal cord and brainstem.

Spinal cord regeneration in Xenopus tadpoles proceeds through activation of Sox2-positive cells

PubMed Central

2012-01-01

Background In contrast to mammals, amphibians, such as adult urodeles (for example, newts) and anuran larvae (for example, Xenopus) can regenerate their spinal cord after injury. However, the cellular and molecular mechanisms involved in this process are still poorly understood. Results Here, we report that tail amputation results in a global increase of Sox2 levels and proliferation of Sox2+ cells. Overexpression of a dominant negative form of Sox2 diminished proliferation of spinal cord resident cells affecting tail regeneration after amputation, suggesting that spinal cord regeneration is crucial for the whole process. After spinal cord transection, Sox2+ cells are found in the ablation gap forming aggregates. Furthermore, Sox2 levels correlated with regenerative capabilities during metamorphosis, observing a decrease in Sox2 levels at non-regenerative stages. Conclusions Sox2+ cells contribute to the regeneration of spinal cord after tail amputation and transection. Sox2 levels decreases during metamorphosis concomitantly with the lost of regenerative capabilities. Our results lead to a working hypothesis in which spinal cord damage activates proliferation and/or migration of Sox2+ cells, thus allowing regeneration of the spinal cord after tail amputation or reconstitution of the ependymal epithelium after spinal cord transection. PMID:22537391

Differential changes in the spinal segmental locomotor output in Hereditary Spastic Paraplegia.

PubMed

Martino, G; Ivanenko, Y; Serrao, M; Ranavolo, A; Draicchio, F; Rinaldi, M; Casali, C; Lacquaniti, F

2018-03-01

A comprehensive treatment of Hereditary Spastic Paraplegia (HSP) should consider the specific pathophysiological changes in the spinal cord. Here we reported a detailed characterization of the spinal motoneuronal output in HSP during locomotion. We recorded kinematics and electromyographic (EMG) activity of 12 leg muscles in 29 patients with pure forms of HSP and compared them with 30 controls while walking at matched speeds. We assessed the spinal locomotor output by evaluating EMG patterns and by mapping them onto the rostrocaudal location of the spinal motoneuron pools. The activity profiles of muscles innervated from the sacral segments were significantly wider in patients. Similarly, spinal maps revealed a tendency for spreading the main loci of activation, involving initially the sacral segments and, at more severe stages, the lumbar segments. The degeneration of the corticospinal tract in HSP is associated with a widening of spinal locomotor output spreading from caudal to rostral segments. The findings highlight pathophysiologically relevant differential changes in the spinal locomotor output in HSP related to the specific innervation of muscles in the spinal cord, and might be helpful for developing future therapeutic strategies and identifying physiological markers of the disease. Copyright © 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Tail Nerve Electrical Stimulation and Electro-Acupuncture Can Protect Spinal Motor Neurons and Alleviate Muscle Atrophy after Spinal Cord Transection in Rats

PubMed Central

Zhang, Yu-Ting; Jin, Hui; Wang, Jun-Hua; Wen, Lan-Yu; Yang, Yang; Ruan, Jing-Wen; Zhang, Shu-Xin; Ling, Eng-Ang

2017-01-01

Spinal cord injury (SCI) often results in death of spinal neurons and atrophy of muscles which they govern. Thus, following SCI, reorganizing the lumbar spinal sensorimotor pathways is crucial to alleviate muscle atrophy. Tail nerve electrical stimulation (TANES) has been shown to activate the central pattern generator (CPG) and improve the locomotion recovery of spinal contused rats. Electroacupuncture (EA) is a traditional Chinese medical practice which has been proven to have a neural protective effect. Here, we examined the effects of TANES and EA on lumbar motor neurons and hindlimb muscle in spinal transected rats, respectively. From the third day postsurgery, rats in the TANES group were treated 5 times a week and those in the EA group were treated once every other day. Four weeks later, both TANES and EA showed a significant impact in promoting survival of lumbar motor neurons and expression of choline acetyltransferase (ChAT) and ameliorating atrophy of hindlimb muscle after SCI. Meanwhile, the expression of neurotrophin-3 (NT-3) in the same spinal cord segment was significantly increased. These findings suggest that TANES and EA can augment the expression of NT-3 in the lumbar spinal cord that appears to protect the motor neurons as well as alleviate muscle atrophy. PMID:28744378

Intraoperative indocyanine green videoangiography for spinal vascular lesions: case report.

PubMed

Murakami, Tomohiro; Koyanagi, Izumi; Kaneko, Takahisa; Iihoshi, Satoshi; Houkin, Kiyohiro

2011-03-01

In surgery of spinal vascular lesions such as spinal arteriovenous fistula or vascular tumors, assessment of feeding arteries and draining veins is important. Intraoperative digital subtraction angiography is useful but is invasive and sometimes technically demanding. Near-infrared indocyanine green (ICG) videoangiography is less invasive and has been reported as an intraoperative diagnosis of arterial patency during clipping surgery of cerebral aneurysms or bypass surgeries. We present our experience with intraoperative ICG videoangiography in 3 cases of spinal vascular lesions. Two patients had spinal arteriovenous fistula (perimedullary, n = 1; dural, n = 1), and 1 patient had spinal cord hemangioblastoma at the thoracic or thoracolumbar level. The surgical microscope was an OPMI Pentero (Carl Zeiss, Oberkochen, Germany). After laminectomy and opening of the dura, ICG (5 mg) was injected intravenously. The ICG angiography clearly demonstrated feeding and draining vessels. The ICG findings greatly helped successful interruption of arteriovenous fistula and total removal of the tumor. Intraoperative ICG videoangiography for spinal vascular lesions was useful by providing information on vascular dynamics directly. However, the diagnostic area is limited to the field of the surgical microscope. Although intraoperative digital subtraction angiography is still needed in cases of complex spinal vascular lesions, ICG videoangiography will be an important diagnostic modality in the field of spinal vascular surgeries.

Twiddler's syndrome in spinal cord stimulation.

PubMed

Al-Mahfoudh, Rafid; Chan, Yuen; Chong, Hsu Pheen; Farah, Jibril Osman

2016-01-01

The aims are to present a case series of Twiddler's syndrome in spinal cord stimulators with analysis of the possible mechanism of this syndrome and discuss how this phenomenon can be prevented. Data were collected retrospectively between 2007 and 2013 for all patients presenting with failure of spinal cord stimulators. The diagnostic criterion for Twiddler's syndrome is radiological evidence of twisting of wires in the presence of failure of spinal cord stimulation. Our unit implants on average 110 spinal cord stimulators a year. Over the 5-year study period, all consecutive cases of spinal cord stimulation failure were studied. Three patients with Twiddler's syndrome were identified. Presentation ranged from 4 to 228 weeks after implantation. Imaging revealed repeated rotations and twisting of the wires of the spinal cord stimulators leading to hardware failure. To the best of our knowledge this is the first reported series of Twiddler's syndrome with implantable pulse generators (IPGs) for spinal cord stimulation. Hardware failure is not uncommon in spinal cord stimulation. Awareness and identification of Twiddler's syndrome may help prevent its occurrence and further revisions. This may be achieved by implanting the IPG in the lumbar region subcutaneously above the belt line. Psychological intervention may have a preventative role for those who are deemed at high risk of Twiddler's syndrome from initial psychological screening.

Characteristics of spinal cord stroke in clinical neurology.

PubMed

Romi, Fredrik; Naess, Halvor

2011-01-01

Spinal cord stroke accounts for about 0.3% of all strokes in our department. Thirty-two patients (15 males, 17 females; mean age 63.3 years) treated in the period 1995-2010 were included. Patients underwent thorough investigation including the use of different stroke scales (National Institute of Health Stroke Scale, Barthel Index and modified Rankin Scale). Twenty-eight patients had infarctions, 3 had hemorrhages, and 1 had arterio-venous fistula. Twenty-eight spinal cord strokes were spontaneous, 2 were secondary to aorta aneurysms, and 2 post surgery. Biphasic ictus was seen in 17% of all spontaneous infarctions. Younger age, male gender, hypertension, diabetes mellitus, and higher blood glucose on admission regardless of diabetes mellitus, were risk factors associated with more severe spinal cord stroke. Treatment and prevention of these risk factors should be essential in spinal cord stroke. We recommend a clinical classification into upper (cervical) and lower (thoracic or medullary conus) spinal cord strokes. Patients with upper strokes in this study had more severe strokes initially, but they had a better prognosis. Therefore it is important to identify this patient group.Acute sensory spinal cord deficit symptoms, common initial symptoms in biphasic spinal cord strokes, should be considered as possible spinal cord stroke, especially when preceded by radiating pain between the shoulders. Copyright © 2011 S. Karger AG, Basel.

Anatomical study of blood supply to the cervical spinal cord in the guinea pig.

PubMed

Mazensky, David; Danko, Jan; Petrovova, Eva; Flesarova, Slavka; Supuka, Peter; Supukova, Anna; Luptakova, Lenka; Purzyc, Halina

2015-06-01

The aim of this study was to describe the arterial arrangement of the cervical spinal cord in the guinea pig. The study was carried out on 20 adult English self guinea pigs using corrosion and dissection technique. Batson's corrosion casting kit no. 17(©) was used as a casting medium. The origin of the ventral spinal artery from the left vertebral artery was found on average in 35% of the cases and from the right vertebral artery on average in 40% of the cases. The ventral spinal artery with origin from the anastomosis of two medial branches was found on average in 25% of the cases. The presence of ventral radicular branches of rami spinales entering the ventral spinal artery in the cervical region was observed in 42% of the cases on the right side and in 58% of the cases on the left side. The presence of dorsal radicular branches of rami spinales that reached the spinal cord was observed in 63% of the cases on the left side and in 37% of the cases on the right side. The number of radicular branches supplying the spinal cord is greater in guinea pig than in humans. © 2014 Japanese Society of Animal Science.

Spinal needle force monitoring during lumbar puncture using fiber Bragg grating force device.

PubMed

Ambastha, Shikha; Umesh, Sharath; Dabir, Sundaresh; Asokan, Sundarrajan

2016-11-01

A technique for real-time dynamic monitoring of force experienced by a spinal needle during lumbar puncture using a fiber Bragg grating (FBG) sensor is presented. The proposed FBG force device (FBGFD) evaluates the compressive force on the spinal needle during lumbar puncture, particularly avoiding the bending effect on the needle. The working principle of the FBGFD is based on transduction of force experienced by the spinal needle into strain variations monitored by the FBG sensor. FBGFD facilitates external mounting of a spinal needle for its smooth insertion during lumbar puncture without any intervention. The developed FBGFD assists study and analysis of the force required for the spinal needle to penetrate various tissue layers from skin to the epidural space; this force is indicative of the varied resistance offered by different tissue layers for the spinal needle traversal. Calibration of FBGFD is performed on a micro-universal testing machine for 0 to 20 N range with an obtained resolution of 0.021 N. The experimental trials using spinal needles mounted on FBGFD are carried out on a human cadaver specimen with punctures made in the lumbar region from different directions. Distinct forces are recorded when the needle encounters skin, muscle tissue, and a bone in its traversing path. Real-time spinal needle force monitoring using FBGFD may reduce potentially serious complications during the lumbar puncture, such as overpuncturing of tissue regions, by impeding the spinal needle insertion at epidural space.

Recurrent and Transient Spinal Pain Among Commercial Helicopter Pilots.

PubMed

Andersen, Knut; Baardsen, Roald; Dalen, Ingvild; Larsen, Jan Petter

2015-11-01

The aim of this study was to provide information on the occurrence of spinal pain, i.e., low back and neck pain, among commercial helicopter pilots, along with possible associations between pain and anthropometric and demographic factors and flying exposure. Data were collected through a subjective and retrospective survey among all the 313 (294 men, 19 women) full-time pilots employed by two helicopter companies. A questionnaire was used to assess the extent of spinal complaints in a transient and recurrent pain pattern along with information on physical activities, occupational flying experience, and airframes. The survey had 207 responders (194 men, 13 women). The pilots had extensive flying experience. Spinal pain was reported by 67%. Flying-related transient pain was reported among 50%, whereas recurrent spinal pain, not necessarily associated with flying, was reported by 52%. Women experienced more pain, but sample size prevented further conclusions. Male pilots reporting any spinal pain flew significantly more hours last year (median 500 h, IQR 400-650) versus men with no pain (median 445 h, IQR 300-550). Male pilots with transient or recurrent spinal pain did not differ from nonaffected male colleagues in the measured parameters. Spinal pain is a frequent problem among male and female commercial helicopter pilots. For men, no significant associations were revealed for transient or recurrent spinal pain with age, flying experience in years, total hours, annual flying time, type of aircraft, or anthropometric factors except for any spinal pain related to hours flown in the last year.