Comparision between Brain Atrophy and Subdural Volume to Predict Chronic Subdural Hematoma: Volumetric CT Imaging Analysis

PubMed Central

Ju, Min-Wook; Kwon, Hyon-Jo; Choi, Seung-Won; Koh, Hyeon-Song; Youm, Jin-Young; Song, Shi-Hun

2015-01-01

Objective Brain atrophy and subdural hygroma were well known factors that enlarge the subdural space, which induced formation of chronic subdural hematoma (CSDH). Thus, we identified the subdural volume that could be used to predict the rate of future CSDH after head trauma using a computed tomography (CT) volumetric analysis. Methods A single institution case-control study was conducted involving 1,186 patients who visited our hospital after head trauma from January 1, 2010 to December 31, 2014. Fifty-one patients with delayed CSDH were identified, and 50 patients with age and sex matched for control. Intracranial volume (ICV), the brain parenchyme, and the subdural space were segmented using CT image-based software. To adjust for variations in head size, volume ratios were assessed as a percentage of ICV [brain volume index (BVI), subdural volume index (SVI)]. The maximum depth of the subdural space on both sides was used to estimate the SVI. Results Before adjusting for cranium size, brain volume tended to be smaller, and subdural space volume was significantly larger in the CSDH group (p=0.138, p=0.021, respectively). The BVI and SVI were significantly different (p=0.003, p=0.001, respectively). SVI [area under the curve (AUC), 77.3%; p=0.008] was a more reliable technique for predicting CSDH than BVI (AUC, 68.1%; p=0.001). Bilateral subdural depth (sum of subdural depth on both sides) increased linearly with SVI (p<0.0001). Conclusion Subdural space volume was significantly larger in CSDH groups. SVI was a more reliable technique for predicting CSDH. Bilateral subdural depth was useful to measure SVI. PMID:27169071

Comparision between Brain Atrophy and Subdural Volume to Predict Chronic Subdural Hematoma: Volumetric CT Imaging Analysis.

PubMed

Ju, Min-Wook; Kim, Seon-Hwan; Kwon, Hyon-Jo; Choi, Seung-Won; Koh, Hyeon-Song; Youm, Jin-Young; Song, Shi-Hun

2015-10-01

Brain atrophy and subdural hygroma were well known factors that enlarge the subdural space, which induced formation of chronic subdural hematoma (CSDH). Thus, we identified the subdural volume that could be used to predict the rate of future CSDH after head trauma using a computed tomography (CT) volumetric analysis. A single institution case-control study was conducted involving 1,186 patients who visited our hospital after head trauma from January 1, 2010 to December 31, 2014. Fifty-one patients with delayed CSDH were identified, and 50 patients with age and sex matched for control. Intracranial volume (ICV), the brain parenchyme, and the subdural space were segmented using CT image-based software. To adjust for variations in head size, volume ratios were assessed as a percentage of ICV [brain volume index (BVI), subdural volume index (SVI)]. The maximum depth of the subdural space on both sides was used to estimate the SVI. Before adjusting for cranium size, brain volume tended to be smaller, and subdural space volume was significantly larger in the CSDH group (p=0.138, p=0.021, respectively). The BVI and SVI were significantly different (p=0.003, p=0.001, respectively). SVI [area under the curve (AUC), 77.3%; p=0.008] was a more reliable technique for predicting CSDH than BVI (AUC, 68.1%; p=0.001). Bilateral subdural depth (sum of subdural depth on both sides) increased linearly with SVI (p<0.0001). Subdural space volume was significantly larger in CSDH groups. SVI was a more reliable technique for predicting CSDH. Bilateral subdural depth was useful to measure SVI.

Analysis of Binary Multivariate Longitudinal Data via 2-Dimensional Orbits: An Application to the Agincourt Health and Socio-Demographic Surveillance System in South Africa

PubMed Central

Visaya, Maria Vivien; Sherwell, David; Sartorius, Benn; Cromieres, Fabien

2015-01-01

We analyse demographic longitudinal survey data of South African (SA) and Mozambican (MOZ) rural households from the Agincourt Health and Socio-Demographic Surveillance System in South Africa. In particular, we determine whether absolute poverty status (APS) is associated with selected household variables pertaining to socio-economic determination, namely household head age, household size, cumulative death, adults to minor ratio, and influx. For comparative purposes, households are classified according to household head nationality (SA or MOZ) and APS (rich or poor). The longitudinal data of each of the four subpopulations (SA rich, SA poor, MOZ rich, and MOZ poor) is a five-dimensional space defined by binary variables (questions), subjects, and time. We use the orbit method to represent binary multivariate longitudinal data (BMLD) of each household as a two-dimensional orbit and to visualise dynamics and behaviour of the population. At each time step, a point (x, y) from the orbit of a household corresponds to the observation of the household, where x is a binary sequence of responses and y is an ordering of variables. The ordering of variables is dynamically rearranged such that clusters and holes associated to least and frequently changing variables in the state space respectively, are exposed. Analysis of orbits reveals information of change at both individual- and population-level, change patterns in the data, capacity of states in the state space, and density of state transitions in the orbits. Analysis of household orbits of the four subpopulations show association between (i) households headed by older adults and rich households, (ii) large household size and poor households, and (iii) households with more minors than adults and poor households. Our results are compared to other methods of BMLD analysis. PMID:25919116

Integrated head package cable carrier for a nuclear power plant

DOEpatents

Meuschke, Robert E.; Trombola, Daniel M.

1995-01-01

A cabling arrangement is provided for a nuclear reactor located within a containment. Structure inside the containment is characterized by a wall having a near side surrounding the reactor vessel defining a cavity, an operating deck outside the cavity, a sub-space below the deck and on a far side of the wall spaced from the near side, and an operating area above the deck. The arrangement includes a movable frame supporting a plurality of cables extending through the frame, each connectable at a first end to a head package on the reactor vessel and each having a second end located in the sub-space. The frame is movable, with the cables, between a first position during normal operation of the reactor when the cables are connected to the head package, located outside the sub-space proximate the head package, and a second position during refueling when the cables are disconnected from the head package, located in the sub-space. In a preferred embodiment, the frame straddles the top of the wall in a substantially horizontal orientation in the first position, pivots about an end distal from the head package to a substantially vertically oriented intermediate position, and is guided, while remaining about vertically oriented, along a track in the sub-space to the second position.

Space Shuttle Columbia Aging Wiring Failure Analysis

NASA Technical Reports Server (NTRS)

McDaniels, Steven J.

2005-01-01

A Space Shuttle Columbia main engine controller 14 AWG wire short circuited during the launch of STS-93. Post-flight examination divulged that the wire had electrically arced against the head of a nearby bolt. More extensive inspection revealed additional damage to the subject wire, and to other wires as well from the mid-body of Columbia. The shorted wire was to have been constructed from nickel-plated copper conductors surrounded by the polyimide insulation Kapton, top-coated with an aromatic polyimide resin. The wires were analyzed via scanning electron microscope (SEM), energy dispersive X-Ray spectroscopy (EDX), and electron spectroscopy for chemical analysis (ESCA); differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) were performed on the polyimide. Exemplar testing under laboratory conditions was performed to replicate the mechanical damage characteristics evident on the failed wires. The exemplar testing included a step test, where, as the name implies, a person stepped on a simulated wire bundle that rested upon a bolt head. Likewise, a shear test that forced a bolt head and a torque tip against a wire was performed to attempt to damage the insulation and conductor. Additionally, a vibration test was performed to determine if a wire bundle would abrade when vibrated against the head of a bolt. Also, an abrasion test was undertaken to determine if the polyimide of the wire could be damaged by rubbing against convolex helical tubing. Finally, an impact test was performed to ascertain if the use of the tubing would protect the wire from the strike of a foreign object.

Gas cushion control of OVJP print head position

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

Forrest, Stephen R

An OVJP apparatus and method for applying organic vapor or other flowable material to a substrate using a printing head mechanism in which the print head spacing from the substrate is controllable using a cushion of air or other gas applied between the print head and substrate. The print head is mounted for translational movement towards and away from the substrate and is biased toward the substrate by springs or other means. A gas cushion feed assembly supplies a gas under pressure between the print head and substrate which opposes the biasing of the print head toward the substrate somore » as to form a space between the print head and substrate. By controlling the pressure of gas supplied, the print head separation from the substrate can be precisely controlled.« less

Single-plane compensatory phase shift of head and eye oscillations in infantile nystagmus syndrome.

PubMed

Anagnostou, Evangelos; Spengos, Konstantinos; Anastasopoulos, Dimitri

2011-09-15

A 43-year-old man with infantile nystagmus syndrome complained of "head tremor" that would occur during attempted reading. Three-dimensional, combined eye and head recordings were performed with the magnetic search coil technique in two conditions: 1) looking straight-ahead under photopic conditions without a particular attentional focus and 2) reading a simple text held one meter away. A mainly vertical-horizontal spontaneous nystagmus was evident in both conditions, whereas head nodding emerged in the second condition. The head oscillated only in the vertical plane and concomitant analysis of eye and head displacement revealed a counterphase, compensatory pattern of the first harmonic of the INS waveform. This was verified by the significant negative peak of the crosscorrelogram at zero lag. Eye-in-space (gaze) displacement during nystagmic oscillations was thereby reduced suggesting a central adaptive behavior that may have evolved to partly compensate for the abnormal eye movements during reading. Copyright © 2011 Elsevier B.V. All rights reserved.

A new markerless patient-to-image registration method using a portable 3D scanner.

PubMed

Fan, Yifeng; Jiang, Dongsheng; Wang, Manning; Song, Zhijian

2014-10-01

Patient-to-image registration is critical to providing surgeons with reliable guidance information in the application of image-guided neurosurgery systems. The conventional point-matching registration method, which is based on skin markers, requires expensive and time-consuming logistic support. Surface-matching registration with facial surface scans is an alternative method, but the registration accuracy is unstable and the error in the more posterior parts of the head is usually large because the scan range is limited. This study proposes a new surface-matching method using a portable 3D scanner to acquire a point cloud of the entire head to perform the patient-to-image registration. A new method for transforming the scan points from the device space into the patient space without calibration and tracking was developed. Five positioning targets were attached on a reference star, and their coordinates in the patient space were measured prior. During registration, the authors moved the scanner around the head to scan its entire surface as well as the positioning targets, and the scanner generated a unique point cloud in the device space. The coordinates of the positioning targets in the device space were automatically detected by the scanner, and a spatial transformation from the device space to the patient space could be calculated by registering them to their coordinates in the patient space that had been measured prior. A three-step registration algorithm was then used to register the patient space to the image space. The authors evaluated their method on a rigid head phantom and an elastic head phantom to verify its practicality and to calculate the target registration error (TRE) in different regions of the head phantoms. The authors also conducted an experiment with a real patient's data to test the feasibility of their method in the clinical environment. In the phantom experiments, the mean fiducial registration error between the device space and the patient space, the mean surface registration error, and the mean TRE of 15 targets on the surface of each phantom were 0.34 ± 0.01 mm and 0.33 ± 0.02 mm, 1.17 ± 0.02 mm and 1.34 ± 0.10 mm, and 1.06 ± 0.11 mm and 1.48 ± 0.21 mm, respectively. When grouping the targets according to their positions on the head, high accuracy was achieved in all parts of the head, and the TREs were similar across different regions. The authors compared their method with the current surface registration methods that use only a part of the facial surface on the elastic phantom, and the mean TRE of 15 targets was 1.48 ± 0.21 mm and 1.98 ± 0.53 mm, respectively. In a clinical experiment, the mean TRE of seven targets on the patient's head surface was 1.92 ± 0.18 mm, which was sufficient to meet clinical requirements. The proposed surface-matching registration method provides sufficient registration accuracy even in the posterior area of the head. The 3D point cloud of the entire head, including the facial surface and the back of the head, can be easily acquired using a portable 3D scanner. The scanner does not need to be calibrated prior or tracked by the optical tracking system during scanning.

Drum bubbler tritium processing system

DOEpatents

Rule, Keith; Gettelfinger, Geoff; Kivler, Paul

1999-01-01

A method of separating tritium oxide from a gas stream containing tritium oxide. The gas stream containing tritium oxide is fed into a container of water having a head space above the water. Bubbling the gas stream containing tritium oxide through the container of water and removing gas from the container head space above the water. Thereafter, the gas from the head space is dried to remove water vapor from the gas, and the water vapor is recycled to the container of water.

Advanced Techniques for Assessment of Postural and Locomotor Ataxia, Spatial Orientation, and Gaze Stability

NASA Technical Reports Server (NTRS)

Wall, Conrad., III

1999-01-01

In addition to adapting to microgravity, major neurovestibular problems of space flight include postflight difficulties with standing, walking, turning corners, and other activities that require stable upright posture and gaze stability. These difficulties inhibit astronauts' ability to stand or escape from their vehicle during emergencies. The long-ter7n goal of the NSBRI is the development of countermeasures to ameliorate the effects of long duration space flight. These countermeasures must be tested with valid and reliable tools. This project aims to develop quantitative, parametric approaches for assessing gaze stability and spatial orientation during normal gait and when gait is perturbed. Two of this year's most important findings concern head fixation distance and ideal trajectory analysis. During a normal cycle of walking the head moves up and down linearly. A simultaneous angular pitching motion of the head keeps it aligned toward an imaginary point in space at a distance of about one meter in front of a subject and along the line of march. This distance is called the head fixation distance. Head fixation distance provides the fundamental framework necessary for understanding the functional significance of the vestibular reflexes that couple head motion to eye motion. This framework facilitates the intelligent design of counter-measures for the effects of exposure to microgravity upon the vestibular ocular reflexes. Ideal trajectory analysis is a simple candidate countermeasure based upon quantifying body sway during repeated up and down stair stepping. It provides one number that estimates the body sway deviation from an ideal sinusoidal body sway trajectory normalized on the subject's height. This concept has been developed with NSBRI funding in less than one year. These findings are explained in more detail below. Compared to assessments of the vestibuo-ocular reflex, analysis of vestibular effects on locomotor function is relatively less well developed and quantified. We are improving this situation by applying methodologies such as nonlinear orbital stability to quantify responses and by using multivariate statistical approaches to link together the responses across separate tests. In this way we can exploit the information available and increase the ability to discriminate between normal and pathological responses. Measures of stability and orientation are compared to measures such as dynamic visual acuity and with balance function tests. The responses of normal human subjects and of patients having well documented pathophysiologies are being characterized. When these studies are completed, we should have a clearer idea about normal and abnormal patterns of eye, head, and body movements during locomotion and their stability in a wide range of environments. We plan eventually to use this information to validate the efficacy of candidate neurovestibular and neuromuscular rehabilitative techniques. Some representative studies made during this year are summarized.

Auditory peripersonal space in humans.

PubMed

Farnè, Alessandro; Làdavas, Elisabetta

2002-10-01

In the present study we report neuropsychological evidence of the existence of an auditory peripersonal space representation around the head in humans and its characteristics. In a group of right brain-damaged patients with tactile extinction, we found that a sound delivered near the ipsilesional side of the head (20 cm) strongly extinguished a tactile stimulus delivered to the contralesional side of the head (cross-modal auditory-tactile extinction). By contrast, when an auditory stimulus was presented far from the head (70 cm), cross-modal extinction was dramatically reduced. This spatially specific cross-modal extinction was most consistently found (i.e., both in the front and back spaces) when a complex sound was presented, like a white noise burst. Pure tones produced spatially specific cross-modal extinction when presented in the back space, but not in the front space. In addition, the most severe cross-modal extinction emerged when sounds came from behind the head, thus showing that the back space is more sensitive than the front space to the sensory interaction of auditory-tactile inputs. Finally, when cross-modal effects were investigated by reversing the spatial arrangement of cross-modal stimuli (i.e., touch on the right and sound on the left), we found that an ipsilesional tactile stimulus, although inducing a small amount of cross-modal tactile-auditory extinction, did not produce any spatial-specific effect. Therefore, the selective aspects of cross-modal interaction found near the head cannot be explained by a competition between a damaged left spatial representation and an intact right spatial representation. Thus, consistent with neurophysiological evidence from monkeys, our findings strongly support the existence, in humans, of an integrated cross-modal system coding auditory and tactile stimuli near the body, that is, in the peripersonal space.

Effect of Floor Space Allowance on Pig Productivity across Stages of Growth: A Field-scale Analysis.

PubMed

Lee, Joon H; Choi, Hong L; Heo, Yong J; Chung, Yoon P

2016-05-01

A total of 152 pig farms were randomly selected from the five provinces in South Korea. During the experiment, the average temperature and relative humidity was 24.7°C and 74% in summer and 2.4°C and 53% in winter, respectively. The correlation between floor space allowance (FSA) and productivity index was analyzed, including non-productive sow days (NPD), number of weaners (NOW), survival rate (SR), appearance rate of A-grade pork (ARA), and days at a slaughter weight of 110 kg (d-SW) at different growth stages. The objectives of the present study were i) to determine the effect of FSA on the pig productivity index and ii) to suggest the minimum FSA for pigs based on scientific baseline data. For the pregnant sow, NPD could be decreased if pregnant sows were raised with a medium level (M) of FSA (3.10 to 3.67 m(2)/head) while also keeping the pig house clean which improves hygiene, and operating the ventilation system properly. For the farrowing sows, the NOW tended to decrease as the FSA increased. Similarly, a high level of FSA (H) is significantly negative with weaner SR of farrowing sows (p-value = 0.017), indicating this FSA tends to depress SR. Therefore, a FSA of 2.30 to 6.40 m(2)/head (very low) could be appropriate for weaners because a limited space can provide a sense of security and protection from external interruptions. The opposite trend was observed that an increase in floor space (>1.12 m(2)/head) leads to increase the SR of growing pigs. For the fattening pigs, H level of FSA was negatively correlated with SR, but M level of FSA was positively correlated with SR, indicating that SR tended to increase with the FSA of 1.10 to 1.27 m(2)/head. In contrast, ARA of male fattening pigs showed opposite results. H level of FSA (1.27 to 1.47 m(2)/head) was suggested to increase productivity because ARA was most affected by H level of space allowance with positive correlation (R(2) = 0.523). The relationship between the FSA and d-SW of fattening pigs was hard to identify because of the low R(2) value. However, the farms that provided a relatively large floor space (1.27 to 1.54 m(2)/head) during the winter period showed d-SW was significantly and negatively affected by FSA.

Vestibular-Somatosensory Convergence in Head Movement Control During Locomotion after Long-Duration Space Flight

NASA Technical Reports Server (NTRS)

Mulavara, Ajitkumar; Ruttley, Tara; Cohen, Helen; Peters, Brian; Miller, Chris; Brady, Rachel; Merkle, Lauren; Bloomberg, Jacob

2010-01-01

Exposure to the microgravity conditions of space flight induces adaptive modification in the control of vestibular-mediated reflexive head movement during locomotion after space flight. Space flight causes astronauts to be exposed to somatosensory adaptation in both the vestibular and body load-sensing (BLS) systems. The goal of these studies was to examine the contributions of vestibular and BLS-mediated somatosensory influences on head movement control during locomotion after long-duration space flight. Subjects were asked to walk on a treadmill driven at 1.8 m/s while performing a visual acuity task. Data were collected using the same testing protocol from three independent subject groups; 1) normal subjects before and after exposure to 30 minutes of 40% bodyweight unloaded treadmill walking, 2) bilateral labyrinthine deficient (LD) patients and 3) astronauts who performed the protocol before and after long duration space flight. Motion data from head and trunk segmental motion data were obtained to calculate the angular head pitch (HP) movements during walking trials while subjects performed the visual task, to estimate the contributions of vestibular reflexive mechanisms in HP movements. Results showed that exposure to unloaded locomotion caused a significant increase in HP movements, whereas in the LD patients the HP movements were significantly decreased. Astronaut subjects results showed a heterogeneous response of both increases and decreases in the amplitude of HP movement. We infer that BLS-mediated somatosensory input centrally modulates vestibular input and can adaptively modify head-movement control during locomotion. Thus, space flight may cause a central adaptation mediated by the converging vestibular and body load-sensing somatosensory systems.

Space flight and neurovestibular adaptation

NASA Technical Reports Server (NTRS)

Reschke, M. F.; Bloomberg, J. J.; Harm, D. L.; Paloski, W. H.

1994-01-01

Space flight represents a form of sensory stimulus rearrangement requiring modification of established terrestrial response patterns through central reinterpretation. Evidence of sensory reinterpretation is manifested as postflight modifications of eye/head coordination, locomotor patterns, postural control strategies, and illusory perceptions of self or surround motion in conjunction with head movements. Under normal preflight conditions, the head is stabilized during locomotion, but immediately postflight reduced head stability, coupled with inappropriate eye/head coordination, results in modifications of gait. Postflight postural control exhibits increased dependence on vision which compensates for inappropriate interpretation of otolith and proprioceptive inputs. Eye movements compensatory for perceived self motion, rather than actual head movements have been observed postflight. Overall, the in-flight adaptive modification of head stabilization strategies, changes in head/eye coordination, illusionary motion, and postural control are maladaptive for a return to the terrestrial environment.

Visual suppression of the vestibulo-ocular reflex during space flight

NASA Technical Reports Server (NTRS)

Uri, John J.; Thornton, William E.; Moore, Thomas P.; Pool, Sam L.

1989-01-01

Visual suppression of the vestibulo-ocular reflex was studied in 16 subjects on 4 Space Shuttle missions. Eye movements were recorded by electro-oculography while subjects fixated a head mounted target during active sinusoidal head oscillation at 0.3 Hz. Adequacy of suppression was evaluated by the number of nystagmus beats, the mean amplitude of each beat, and the cumulative amplitude of nystagmus during two head oscillation cycles. Vestibulo-ocular reflex suppression was unaffected by space flight. Subjects with space motion sickness during flight had significantly more nystagmus beats than unaffected individuals. These susceptible subjects also tended to have more nystagmus beats before flight.

Two particle model for studying the effects of space-charge force on strong head-tail instabilities

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

Chin, Yong Ho; Chao, Alexander Wu; Blaskiewicz, Michael M.

In this paper, we present a new two particle model for studying the strong head-tail instabilities in the presence of the space-charge force. It is a simple expansion of the well-known two particle model for strong head-tail instability and is still analytically solvable. No chromaticity effect is included. It leads to a formula for the growth rate as a function of the two dimensionless parameters: the space-charge tune shift parameter (normalized by the synchrotron tune) and the wakefield strength, Upsilon. The three-dimensional contour plot of the growth rate as a function of those two dimensionless parameters reveals stopband structures. Manymore » simulation results generally indicate that a strong head-tail instability can be damped by a weak space-charge force, but the beam becomes unstable again when the space-charge force is further increased. The new two particle model indicates a similar behavior. In weak space-charge regions, additional tune shifts by the space-charge force dissolve the mode coupling. As the space-charge force is increased, they conversely restore the mode coupling, but then a further increase of the space-charge force decouples the modes again. Lastly, this mode coupling/decoupling behavior creates the stopband structures.« less

Two particle model for studying the effects of space-charge force on strong head-tail instabilities

DOE PAGES

Chin, Yong Ho; Chao, Alexander Wu; Blaskiewicz, Michael M.

2016-01-19

In this paper, we present a new two particle model for studying the strong head-tail instabilities in the presence of the space-charge force. It is a simple expansion of the well-known two particle model for strong head-tail instability and is still analytically solvable. No chromaticity effect is included. It leads to a formula for the growth rate as a function of the two dimensionless parameters: the space-charge tune shift parameter (normalized by the synchrotron tune) and the wakefield strength, Upsilon. The three-dimensional contour plot of the growth rate as a function of those two dimensionless parameters reveals stopband structures. Manymore » simulation results generally indicate that a strong head-tail instability can be damped by a weak space-charge force, but the beam becomes unstable again when the space-charge force is further increased. The new two particle model indicates a similar behavior. In weak space-charge regions, additional tune shifts by the space-charge force dissolve the mode coupling. As the space-charge force is increased, they conversely restore the mode coupling, but then a further increase of the space-charge force decouples the modes again. Lastly, this mode coupling/decoupling behavior creates the stopband structures.« less

Drum bubbler tritium processing system

DOEpatents

Rule, K.; Gettelfinger, G.; Kivler, P.

1999-08-17

A method is described for separating tritium oxide from a gas stream containing tritium oxide. The gas stream containing tritium oxide is fed into a container of water having a head space above the water. The tritium oxide is separated by bubbling the gas stream containing tritium oxide through the container of water and removing gas from the container head space above the water. Thereafter, the gas from the head space is dried to remove water vapor from the gas, and the water vapor is recycled to the container of water. 2 figs.

Integration of vestibular and head movement signals in the vestibular nuclei during whole-body rotation

NASA Technical Reports Server (NTRS)

Gdowski, G. T.; McCrea, R. A.; Peterson, B. W. (Principal Investigator)

1999-01-01

Single-unit recordings were obtained from 107 horizontal semicircular canal-related central vestibular neurons in three alert squirrel monkeys during passive sinusoidal whole-body rotation (WBR) while the head was free to move in the yaw plane (2.3 Hz, 20 degrees /s). Most of the units were identified as secondary vestibular neurons by electrical stimulation of the ipsilateral vestibular nerve (61/80 tested). Both non-eye-movement (n = 52) and eye-movement-related (n = 55) units were studied. Unit responses recorded when the head was free to move were compared with responses recorded when the head was restrained from moving. WBR in the absence of a visual target evoked a compensatory vestibulocollic reflex (VCR) that effectively reduced the head velocity in space by an average of 33 +/- 14%. In 73 units, the compensatory head movements were sufficiently large to permit the effect of the VCR on vestibular signal processing to be assessed quantitatively. The VCR affected the rotational responses of different vestibular neurons in different ways. Approximately one-half of the units (34/73, 47%) had responses that decreased as head velocity decreased. However, the responses of many other units (24/73) showed little change. These cells had signals that were better correlated with trunk velocity than with head velocity. The remaining units had responses that were significantly larger (15/73, 21%) when the VCR produced a decrease in head velocity. Eye-movement-related units tended to have rotational responses that were correlated with head velocity. On the other hand, non-eye-movement units tended to have rotational responses that were better correlated with trunk velocity. We conclude that sensory vestibular signals are transformed from head-in-space coordinates to trunk-in-space coordinates on many secondary vestibular neurons in the vestibular nuclei by the addition of inputs related to head rotation on the trunk. This coordinate transformation is presumably important for controlling postural reflexes and constructing a central percept of body orientation and movement in space.

An automatic markerless registration method for neurosurgical robotics based on an optical camera.

PubMed

Meng, Fanle; Zhai, Fangwen; Zeng, Bowei; Ding, Hui; Wang, Guangzhi

2018-02-01

Current markerless registration methods for neurosurgical robotics use the facial surface to match the robot space with the image space, and acquisition of the facial surface usually requires manual interaction and constrains the patient to a supine position. To overcome these drawbacks, we propose a registration method that is automatic and does not constrain patient position. An optical camera attached to the robot end effector captures images around the patient's head from multiple views. Then, high coverage of the head surface is reconstructed from the images through multi-view stereo vision. Since the acquired head surface point cloud contains color information, a specific mark that is manually drawn on the patient's head prior to the capture procedure can be extracted to automatically accomplish coarse registration rather than using facial anatomic landmarks. Then, fine registration is achieved by registering the high coverage of the head surface without relying solely on the facial region, thus eliminating patient position constraints. The head surface was acquired by the camera with a good repeatability accuracy. The average target registration error of 8 different patient positions measured with targets inside a head phantom was [Formula: see text], while the mean surface registration error was [Formula: see text]. The method proposed in this paper achieves automatic markerless registration in multiple patient positions and guarantees registration accuracy inside the head. This method provides a new approach for establishing the spatial relationship between the image space and the robot space.

Robust Head-Pose Estimation Based on Partially-Latent Mixture of Linear Regressions.

PubMed

Drouard, Vincent; Horaud, Radu; Deleforge, Antoine; Ba, Sileye; Evangelidis, Georgios

2017-03-01

Head-pose estimation has many applications, such as social event analysis, human-robot and human-computer interaction, driving assistance, and so forth. Head-pose estimation is challenging, because it must cope with changing illumination conditions, variabilities in face orientation and in appearance, partial occlusions of facial landmarks, as well as bounding-box-to-face alignment errors. We propose to use a mixture of linear regressions with partially-latent output. This regression method learns to map high-dimensional feature vectors (extracted from bounding boxes of faces) onto the joint space of head-pose angles and bounding-box shifts, such that they are robustly predicted in the presence of unobservable phenomena. We describe in detail the mapping method that combines the merits of unsupervised manifold learning techniques and of mixtures of regressions. We validate our method with three publicly available data sets and we thoroughly benchmark four variants of the proposed algorithm with several state-of-the-art head-pose estimation methods.

Spatial Reorientation of Sensorimotor Balance Control in Altered Gravity

NASA Technical Reports Server (NTRS)

Paloski, W. H.; Black, F. L.; Kaufman, G. D.; Reschke, M. F.; Wood, S. J.

2007-01-01

Sensorimotor coordination of body segments following space flight are more pronounced after landing when the head is actively tilted with respect to the trunk. This suggests that central vestibular processing shifts from a gravitational frame of reference to a head frame of reference in microgravity. A major effect of such changes is a significant postural instability documented by standard head-erect Sensory Organization Tests. Decrements in functional performance may still be underestimated when head and gravity reference frames remained aligned. The purpose of this study was to examine adaptive changes in spatial processing for balance control following space flight by incorporating static and dynamic tilts that dissociate head and gravity reference frames. A second aim of this study was to examine the feasibility of altering the re-adaptation process following space flight by providing discordant visual-vestibular-somatosensory stimuli using short-radius pitch centrifugation.

Effects of implant design parameters on fluid convection, potentiating third-body debris ingress into the bearing surface during THA impingement/subluxation.

PubMed

Lundberg, Hannah J; Pedersen, Douglas R; Baer, Thomas E; Muste, Marian; Callaghan, John J; Brown, Thomas D

2007-01-01

Aseptic loosening from polyethylene wear debris is the leading cause of failure for metal-on-polyethylene total hip implants. Third-body debris ingress to the bearing space results in femoral head roughening and acceleration of polyethylene wear. How third-body particles manage to enter the bearing space between the closely conforming articulating surfaces of the joint is not well understood. We hypothesize that one such mechanism is from convective fluid transport during subluxation of the total hip joint. To test this hypothesis, a three-dimensional (3D) computational fluid dynamics (CFD) model was developed and validated, to quantify fluid ingress into the bearing space during a leg-cross subluxation event. The results indicated that extra-articular joint fluid could be drawn nearly to the pole of the cup with even very small separations of the femoral head (<0.60mm). Debris suspended near the equator of the cup at the site of maximum fluid velocity just before the subluxation began could be transported to within 11 degrees from the cup pole. Larger head diameters resulted in increased fluid velocity at all sites around the entrance to the gap compared to smaller head sizes, with fluid velocity being greatest along the anterosuperolateral cup edge, for all head sizes. Fluid pathlines indicated that suspended debris would reach similar angular positions in the bearing space regardless of head size. Increased inset of the femoral head into the acetabular cup resulted both in higher fluid velocity and in transport of third-body debris further into the bearing space.

Head movements in low and high gravitoinertial force environments elicit motion sickness - Implications for space motion sickness

NASA Technical Reports Server (NTRS)

Lackner, James R.; Graybiel, Ashton

1987-01-01

Astronauts report that head movements in flight tend to bring on symptoms of space motion sickness (SMS). The effects of head movements in pitch, yaw, and roll (made both with normal vision and with eyes occluded) on susceptibility to motion sickness in the zero G phase of parabolic flight maneuvers were evaluated. The findings are clear-cut: pitch head movements are most provocative, yaw least provocative, and roll intermediate. These experiments suggest that SMS is not a unique nosological entity, but is the consequence of exposure to nonterrestrial force levels. Head movements during departures in either direction from 1 G elicit symptoms.

Space flight and changes in spatial orientation

NASA Technical Reports Server (NTRS)

Reschke, Millard F.; Bloomberg, Jacob J.; Harm, Deborah L.; Paloski, William H.

1992-01-01

From a sensory point of view, space flight represents a form of stimulus rearrangement requiring modification of established terrestrial response patterns through central reinterpretation. Evidence of sensory reinterpretation is manifested as postflight modifications of eye/head coordination, locomotor patterns, postural control strategies, and illusory perceptions of self or surround motion in conjunction with head movements. Under normal preflight conditions, the head is stabilized during locomotion, but immediately postflight reduced head stability, coupled with inappropriate eye/head coordination, results in modifications of gait. Postflight postural control exhibits increased dependence on vision which compensates for inappropriate interpretation of otolith and proprioceptive inputs. Eye movements compensatory for perceived self motion, rather than actual head movements have been observed postflight. Overall, the in-flight adaptive modification of head stabilization strategies, changes in head/eye coordination, illusionary motion, and postural control are maladaptive for a return to the terrestrial environment. Appropriate countermeasures for long-duration flights will rely on preflight adaptation and in-flight training.

Star-coupled Hindmarsh-Rose neural network with chemical synapses

NASA Astrophysics Data System (ADS)

Usha, K.; Subha, P. A.

We analyze the patterns like synchrony, desynchrony, and Drum head mode in a network of Hindmarsh-Rose (HR) neurons interacting via chemical synapse in unidirectional and bidirectional star topology. A two-coupled system has been studied for synchronization by varying the coupling strength and the parameter describing the activation and inactivation of the fast ion channel. The transverse Lyapunov exponent spectrum is plotted to observe the point of transition from desynchrony to synchrony. The synchronized, desynchronized, and drum head mode regions are observed when the neurons are connected in unidirectional and bidirectional coupling configurations. A detailed analysis about the time evolution of membrane potential corresponding to each region is presented. The annihilation of synchronized region and the expansion of drum head mode region in bidirectional coupling is discussed using parameter space. Our work provides finer insight into the existence and stability of Drum head mode and is useful for designing communication networks.

Orthostatic function during a stand test before and after head-up or head-down bedrest

NASA Technical Reports Server (NTRS)

Lathers, Claire M.; Diamandis, Peter H.; Riddle, Jeanne M.; Mukai, Chiaki; Elton, Kay F.; Bungo, Michael W.; Charles, John B.

1991-01-01

The effects of head-down or head-up bedrest at -5, +10, +20, or +42 deg (simulating 0, 1/6, 1/3, and 2/3 g, respectively) for 6 hrs on four different days on the orthostatic tolerance were investigated by measuring relevant physiological reactions to orthostatic test taken before and after bedrest sessions. The multivariate analysis of variance statistical analyses indicates that there was no angle effect on any of the cardiovascular parameters monitored during the last 3 min of the stand test, suggesting that partial gravity loads would have no effect on the cardiovascular deconditioning exhibited postflight. There was, however, a significant elevation in the heart rate post-bedrest, and the heart rate increased on standing. Results from the stand test pre- and post-bedrest at -5 deg (but not at +10, +20, and +42 deg) were similar to those observed after space flight.

Normal radiological unossified hip joint space and femoral head size development during growth in 675 children and adolescents.

PubMed

Wegener, Veronika; Jorysz, Gabriele; Arnoldi, Andreas; Utzschneider, Sandra; Wegener, Bernd; Jansson, Volkmar; Heimkes, Bernhard

2017-03-01

Evaluation of hip joint space width during child growth is important to aid in the early diagnosis of hip pathology in children. We established reference values for hip joint space and femoral head size for each age. Hip joint space development during growth was retrospectively investigated medial and cranial in 1350 hip joints of children using standard anteroposterior supine plain pelvic radiographs. Maximum capital femoral epiphysis diameter and femoral radii were further more investigated. Hip joint space values show a slow decline during growth. Joint space was statistically significantly (p < 0.006) larger in boys than girls. Our hip joint space measurements on supine subjects seem slightly larger than those reported by Hughes on standing subjects. Evaluation of the femoral head diameter and the radii showed a size curve quite parallel to the known body growth charts. Radii medial and perpendicular to the physis are not statistically significantly different. We recommend to compare measurements of hip joint space at two locations to age dependent charts using the same imaging technique. During growth, a divergence in femoral head size from the expected values or loss of the spherical shape should raise the question of hip disorder. Clin. Anat. 30:267-275, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Space use by white-headed woodpeckers and selection for recent forest disturbances

Treesearch

Teresa J. Lorenz; Kerri T. Vierling; Jeffrey M. Kozma; Janet E. Millard; Martin G. Raphael

2015-01-01

White-headed woodpeckers (Picoides albolarvatus) are important cavity excavators that recently have become the focus of much research because of concerns over population declines. Past studies have focused on nest site selection and survival but information is needed on factors influencing their space use when away from the nest. We examined space...

Cross-Cultural Study on the Effect of Space and Teacher Controlling Behavior.

ERIC Educational Resources Information Center

Perry, Gail

The purpose of this study was to determine the effect classroom space had on teacher behavior. It was hypothesized that Head Start teachers in classrooms with inadequate space (less than 30 square feet per child) would exhibit more controlling behavior toward children than would Head Start teachers in classrooms with an adequate amount of space…

Probability distributions of whisker-surface contact: quantifying elements of the rat vibrissotactile natural scene.

PubMed

Hobbs, Jennifer A; Towal, R Blythe; Hartmann, Mitra J Z

2015-08-01

Analysis of natural scene statistics has been a powerful approach for understanding neural coding in the auditory and visual systems. In the field of somatosensation, it has been more challenging to quantify the natural tactile scene, in part because somatosensory signals are so tightly linked to the animal's movements. The present work takes a step towards quantifying the natural tactile scene for the rat vibrissal system by simulating rat whisking motions to systematically investigate the probabilities of whisker-object contact in naturalistic environments. The simulations permit an exhaustive search through the complete space of possible contact patterns, thereby allowing for the characterization of the patterns that would most likely occur during long sequences of natural exploratory behavior. We specifically quantified the probabilities of 'concomitant contact', that is, given that a particular whisker makes contact with a surface during a whisk, what is the probability that each of the other whiskers will also make contact with the surface during that whisk? Probabilities of concomitant contact were quantified in simulations that assumed increasingly naturalistic conditions: first, the space of all possible head poses; second, the space of behaviorally preferred head poses as measured experimentally; and third, common head poses in environments such as cages and burrows. As environments became more naturalistic, the probability distributions shifted from exhibiting a 'row-wise' structure to a more diagonal structure. Results also reveal that the rat appears to use motor strategies (e.g. head pitches) that generate contact patterns that are particularly well suited to extract information in the presence of uncertainty. © 2015. Published by The Company of Biologists Ltd.

Space radiation studies

NASA Technical Reports Server (NTRS)

Gregory, J. C.

1986-01-01

Instrument design and data analysis expertise was provided in support of several space radiation monitoring programs. The Verification of Flight Instrumentation (VFI) program at NASA included both the Active Radiation Detector (ARD) and the Nuclear Radiation Monitor (NRM). Design, partial fabrication, calibration and partial data analysis capability to the ARD program was provided, as well as detector head design and fabrication, software development and partial data analysis capability to the NRM program. The ARD flew on Spacelab-1 in 1983, performed flawlessly and was returned to MSFC after flight with unchanged calibration factors. The NRM, flown on Spacelab-2 in 1985, also performed without fault, not only recording the ambient gamma ray background on the Spacelab, but also recording radiation events of astrophysical significance.

New mini dental implant attachments versus O-ring attachment after cyclic aging: Analysis of retention strength and gap space.

PubMed

Fatalla, Abdalbseet A; Song, Ke; Cao, Ying-Guang

2017-06-01

Overdenture as a treatment modality for both partially and fully edentulous patients is costeffective and less expensive. The purpose of the present study was to examine the newly fabricated attachments by comparing them with conventional O-ring attachment in vitro in terms of retention force and cyclic aging resistance. A total of 150 samples were prepared and divided into five groups according to the materials used (O-ring attachment, Deflex M10 XR, Deflex Classic SR, Deflex Acrilato FD, and flexible acrylic resin). The retention force of different attachments was measured by a mini dental implant after three subsequent aging (0, 63, and 126) cycles in the circumstances similar to the oral environment. The gap space between the head of the implant and the inner surface of the attachments was detected. Two-way analysis of variance (ANOVA) analysis with multiple comparisons test was applied for statistical analysis. The results showed that Deflex M10 XR had the highest retention force and the lowest gap space after cyclic aging; in addition, by comparing the relative force reduction, the lowest values were obtained in the O-ring attachment and the highest values in the flexible acrylic resin attachment. The retention force measured after cyclic aging for the Deflex M10 XR attachment was greatly improved when compared with the O-ring attachment and other types of attachment materials; in addition, the Deflex M10 XR attachment exhibited the minimum gap space between the inner surface and the mini dental implant head. In conclusion, Deflex M10 XR has the ability to withstand weathering conditions and retains its durable and retentive properties after aging when compared with other attachments.

Stabilization and mobility of the head and trunk in wild monkeys during terrestrial and flat-surface walks and gallops.

PubMed

Dunbar, Donald C; Badam, Gyani L; Hallgrímsson, Benedikt; Vieilledent, Stéphane

2004-02-01

This study investigated the patterns of rotational mobility (> or =20 degrees ) and stability (< or =20 degrees ) of the head and trunk in wild Indian monkeys during natural locomotion on the ground and on the flat-topped surfaces of walls. Adult hanuman langurs (Semnopithecus entellus) and bonnet macaques (Macaca radiata) of either gender were cine filmed in lateral view. Whole-body horizontal linear displacement, head and trunk pitch displacement relative to space (earth horizontal), and vertical head displacement were measured from the cine films. Head-to-trunk pitch angle was calculated from the head-to-space and trunk-to-space measurements. Locomotor velocities, cycle durations, angular segmental velocities, mean segmental positions and mean peak frequencies of vertical and angular head displacements were then calculated from the displacement data. Yaw rotations were observed qualitatively. During quadrupedal walks by both species, the head was free to rotate in the pitch and yaw planes on a stabilized trunk. By contrast, during quadrupedal gallops by both species, the trunk pitched on a stabilized head. During both gaits in both species, head and trunk pitch rotations were symmetrical about comparable mean positions in both gaits, with mean head position aligning the horizontal semicircular canals near earth horizontal. Head pitch direction countered head vertical displacement direction to varying degrees during walks and only intermittently during gallops, providing evidence that correctional head pitch rotations are not essential for gaze stabilization. Head-to-space pitch velocities were below 350 deg. s(-1), the threshold above which, at least among humans, the vestibulo-ocular reflex (VOR) becomes saturated. Mean peak frequencies of vertical translations and pitch rotations of the head ranged from 1 Hz to 2 Hz, a lower frequency range than that in which inertia is predicted to be the major stabilizer of the head in these species. Some variables, which were common to both walks and gallops in both species, are likely to reflect constraints in sensorimotor control. Other variables, which differed between the two gaits in both species, are likely to reflect kinematic differences, whereas variables that differed between the two species are attributed primarily to morphological and behavioural differences. It is concluded that either the head or the trunk can provide the nervous system with a reference frame for spatial orientation and that the segment providing that reference can change, depending upon the kinematic characteristics of the chosen gait.

Engine having a variable valve actuation system

DOEpatents

Hefler, Gregory W [Chillicothe, IL

2004-10-12

An engine has a cylinder head having a first surface and a second surface spaced from the first surface. A valve is moveably connected to the cylinder head. A rocker arm is connected to the valve, and a rocker shaft having a first location spaced a maximum distance from the cylinder head is connected to the rocker arm. A support member has and an actuator fluid passage network. The actuator fluid passage network defines a volume. The support member is connected to the cylinder head and is positioned such that a majority of the volume of the actuator fluid passage network is between the first location of the rocker shaft and the second surface of the cylinder head.

Engine having a variable valve actuation system

DOEpatents

Hefler, Gregory W.

2005-10-12

An engine has a cylinder head having a first surface and a second surface spaced from the first surface. A valve is moveably connected to the cylinder head. A rocker arm is connected to the valve, and a rocker shaft having a first location spaced a maximum distance from the cylinder head is connected to the rocker arm. A support member has and an actuator fluid passage network. The actuator fluid passage network defines a volume. The support member is connected to the cylinder head and is positioned such that a majority of the volume of the actuator fluid passage network is between the first location of the rocker shaft and the second surface of the cylinder head.

Shipboard Facilities Maintenance and Manpower Utilization: Problem and Approach

DTIC Science & Technology

1975-11-01

sweeping, butting, polishing, lacquering, stenciling, vacuuming and shampooing , garbage disposal and trash removal, and all manner of sanitary and...spaces, passageways, heads and showers, crew lounge, mess decks, exterior deck and ship sides, and all office spaces; and limited facilities...maintenance in all passageways, heads , mess decks, office spaces, and berthing areas. They will also per- form sanitization and exterior deck and

Eye-Head Coordination in 31 Space Shuttle Astronauts during Visual Target Acquisition.

PubMed

Reschke, Millard F; Kolev, Ognyan I; Clément, Gilles

2017-10-27

Between 1989 and 1995, NASA evaluated how increases in flight duration of up to 17 days affected the health and performance of Space Shuttle astronauts. Thirty-one Space Shuttle pilots participating in 17 space missions were tested at 3 different times before flight and 3 different times after flight, starting within a few hours of return to Earth. The astronauts moved their head and eyes as quickly as possible from the central fixation point to a specified target located 20°, 30°, or 60° off center. Eye movements were measured with electro-oculography (EOG). Head movements were measured with a triaxial rate sensor system mounted on a headband. The mean time to visually acquire the targets immediately after landing was 7-10% (30-34 ms) slower than mean preflight values, but results returned to baseline after 48 hours. This increase in gaze latency was due to a decrease in velocity and amplitude of both the eye saccade and head movement toward the target. Results were similar after all space missions, regardless of length.

Analysis of gravity-induced particle motion and fluid perfusion flow in the NASA-designed rotating zero-head-space tissue culture vessel

NASA Technical Reports Server (NTRS)

Wolf, David A.; Schwarz, Ray P.

1991-01-01

The gravity induced motions, through the culture media, is calculated of living tissue segments cultured in the NASA rotating zero head space culture vessels. This is then compared with the media perfusion speed which is independent of gravity. The results may be interpreted as a change in the physical environment which will occur by operating the NASA tissue culture systems in actual microgravity (versus unit gravity). The equations governing particle motions which induce flows at the surface of tissues contain g terms. This allows calculation of the fluid flow speed, with respect to a cultured particle, as a function of the external gravitational field strength. The analysis is approached from a flow field perspective. Flow is proportional to the shear exerted on a structure which maintains position within the field. The equations are solved for the deviation of a particle from its original position in a circular streamline as a function of time. The radial deviation is important for defining the operating limits and dimensions of the vessel because of the finite radius at which particles necessarily intercept the wall. This analysis uses a rotating reference frame concept.

LDEF Materials/Contamination

NASA Technical Reports Server (NTRS)

Pippin, Gary

1997-01-01

This pictorial presentation reviews the post-flight analysis results from two type of hardware (tray clamp bolt heads and uhcre flight experiment tray walls) from the Long Duration Exposure Facility (LDEF). It will also discuss flight hardware for one upcoming (Effects of the Space Environment on Materials (ESEM) flight experiment), and two current flight experiments evaluating the performance of materials in space (Passive Optical Sample Assembly (POSA) 1&2 flight experiments. These flight experiments also are concerned with contamination effects which will also be discussed.

Head-Disk Interface Technology: Challenges and Approaches

NASA Astrophysics Data System (ADS)

Liu, Bo

Magnetic hard disk drive (HDD) technology is believed to be one of the most successful examples of modern mechatronics systems. The mechanical beauty of magnetic HDD includes simple but super high accuracy positioning head, positioning technology, high speed and stability spindle motor technology, and head-disk interface technology which keeps the millimeter sized slider flying over a disk surface at nanometer level slider-disk spacing. This paper addresses the challenges and possible approaches on how to further reduce the slider disk spacing whilst retaining the stability and robustness level of head-disk systems for future advanced magnetic disk drives.

High efficiency pump for space helium transfer

NASA Technical Reports Server (NTRS)

Hasenbein, Robert; Izenson, Michael G.; Swift, Walter L.; Sixsmith, Herbert

1991-01-01

A centrifugal pump was developed for the efficient and reliable transfer of liquid helium in space. The pump can be used to refill cryostats on orbiting satellites which use liquid helium for refrigeration at extremely low temperatures. The pump meets the head and flow requirements of on-orbit helium transfer: a flow rate of 800 L/hr at a head of 128 J/kg. The overall pump efficiency at the design point is 0.45. The design head and flow requirements are met with zero net positive suction head, which is the condition in an orbiting helium supply Dewar. The mass transfer efficiency calculated for a space transfer operation is 0.99. Steel ball bearings are used with gas fiber-reinforced teflon retainers to provide solid lubrication. These bearings have demonstrated the longest life in liquid helium endurance tests under simulated pumping conditions. Technology developed in the project also has application for liquid helium circulation in terrestrial facilities and for transfer of cryogenic rocket propellants in space.

Texting and Walking: Strategies for Postural Control and Implications for Safety

PubMed Central

Schabrun, Siobhan M.; van den Hoorn, Wolbert; Moorcroft, Alison; Greenland, Cameron; Hodges, Paul W.

2014-01-01

There are concerns about the safety of texting while walking. Although evidence of negative effects of mobile phone use on gait is scarce, cognitive distraction, altered mechanical demands, and the reduced visual field associated with texting are likely to have an impact. In 26 healthy individuals we examined the effect of mobile phone use on gait. Individuals walked at a comfortable pace in a straight line over a distance of ∼8.5 m while; 1) walking without the use of a phone, 2) reading text on a mobile phone, or 3) typing text on a mobile phone. Gait performance was evaluated using a three-dimensional movement analysis system. In comparison with normal waking, when participants read or wrote text messages they walked with: greater absolute lateral foot position from one stride to the next; slower speed; greater rotation range of motion (ROM) of the head with respect to global space; the head held in a flexed position; more in-phase motion of the thorax and head in all planes, less motion between thorax and head (neck ROM); and more tightly organized coordination in lateral flexion and rotation directions. While writing text, participants walked slower, deviated more from a straight line and used less neck ROM than reading text. Although the arms and head moved with the thorax to reduce relative motion of the phone and facilitate reading and texting, movement of the head in global space increased and this could negatively impact the balance system. Texting, and to a lesser extent reading, modify gait performance. Texting or reading on a mobile phone may pose an additional risk to safety for pedestrians navigating obstacles or crossing the road. PMID:24465402

Apparatus and method to keep the walls of a free-space reactor free from deposits of solid materials

NASA Technical Reports Server (NTRS)

Yamakawa, K. A. (Inventor)

1985-01-01

An apparatus and method is disclosed for keeping interior walls of a reaction vessel free of undesirable deposits of solid materials in gas-to-solid reactions. The apparatus includes a movable cleaning head which is configured to be substantially complementary to the interior contour of the walls of the reaction vessel. The head ejects a stream of gas with a relatively high velocity into a narrow space between the head and the walls. The head is moved substantially continuously to at least intermittently blow the stream of gas to substantially the entire surface of the walls wherein undesirable solid deposition is likely to occur. The disclosed apparatus and process is particularly useful for keeping the walls of a free-space silane-gas-to-solid-silicon reactor free of undesirable silicon deposits.

Using EMG to anticipate head motion for virtual-environment applications

NASA Technical Reports Server (NTRS)

Barniv, Yair; Aguilar, Mario; Hasanbelliu, Erion

2005-01-01

In virtual environment (VE) applications, where virtual objects are presented in a see-through head-mounted display, virtual images must be continuously stabilized in space in response to user's head motion. Time delays in head-motion compensation cause virtual objects to "swim" around instead of being stable in space which results in misalignment errors when overlaying virtual and real objects. Visual update delays are a critical technical obstacle for implementing head-mounted displays in applications such as battlefield simulation/training, telerobotics, and telemedicine. Head motion is currently measurable by a head-mounted 6-degrees-of-freedom inertial measurement unit. However, even given this information, overall VE-system latencies cannot be reduced under about 25 ms. We present a novel approach to eliminating latencies, which is premised on the fact that myoelectric signals from a muscle precede its exertion of force, thereby limb or head acceleration. We thus suggest utilizing neck-muscles' myoelectric signals to anticipate head motion. We trained a neural network to map such signals onto equivalent time-advanced inertial outputs. The resulting network can achieve time advances of up to 70 ms.

Using EMG to anticipate head motion for virtual-environment applications.

PubMed

Barniv, Yair; Aguilar, Mario; Hasanbelliu, Erion

2005-06-01

In virtual environment (VE) applications, where virtual objects are presented in a see-through head-mounted display, virtual images must be continuously stabilized in space in response to user's head motion. Time delays in head-motion compensation cause virtual objects to "swim" around instead of being stable in space which results in misalignment errors when overlaying virtual and real objects. Visual update delays are a critical technical obstacle for implementing head-mounted displays in applications such as battlefield simulation/training, telerobotics, and telemedicine. Head motion is currently measurable by a head-mounted 6-degrees-of-freedom inertial measurement unit. However, even given this information, overall VE-system latencies cannot be reduced under about 25 ms. We present a novel approach to eliminating latencies, which is premised on the fact that myoelectric signals from a muscle precede its exertion of force, thereby limb or head acceleration. We thus suggest utilizing neck-muscles' myoelectric signals to anticipate head motion. We trained a neural network to map such signals onto equivalent time-advanced inertial outputs. The resulting network can achieve time advances of up to 70 ms.

Visual-Vestibular Responses During Space Flight

NASA Technical Reports Server (NTRS)

Reschke, M. F.; Kozlovskaya, I. B.; Paloski, W. H.

1999-01-01

Given the documented disruptions that occur in spatial orientation during space flight and the putative sensory-motor information underlying eye and head spatial coding, the primary purpose of this paper is to examine components of the target acquisition system in subjects free to make head and eye movements in three dimensional space both during and following adaptation to long duration space flight. It is also our intention to suggest a simple model of adaptation that has components in common with cerebellar disorders whose neurobiological substrate has been identified.

Space Applications Industrial Laser System (SAILS)

NASA Technical Reports Server (NTRS)

Mccay, T. D.; Bible, J. B.; Mueller, R. E.

1993-01-01

A program is underway to develop a YAG laser based materials processing workstation to fly in the cargo bay of the Space Shuttle. This workstation, called Space Applications Industrial Laser System (SAILS), will be capable of cutting and welding steel, aluminum, and Inconel alloys of the type planned for use in constructing the Space Station Freedom. As well as demonstrating the ability of a YAG laser to perform remote (fiber-optic delivered) repair and fabrication operations in space, fundamental data will be collected on these interactions for comparison with terrestrial data and models. The flight system, scheduled to fly in 1996, will be constructed as three modules using standard Get-Away-Special (GAS) canisters. The first module holds the laser head and cooling system, while the second contains a high peak power electrical supply. The third module houses the materials processing workstation and the command and data acquisition subsystems. The laser head and workstation cansisters are linked by a fiber-optic cable to transmit the laser light. The team assembled to carry out this project includes Lumonics Industrial Products (laser), Tennessee Technological University (structural analysis and fabrication), Auburn University Center for Space Power (electrical engineering), University of Waterloo (low-g laser process consulting), and CSTAR/UTSI (data acquisition, control, software, integration, experiment design). This report describes the SAILS program and highlights recent activities undertaken at CSTAR.

Reliability-Based Life Assessment of Stirling Convertor Heater Head

NASA Technical Reports Server (NTRS)

Shah, Ashwin R.; Halford, Gary R.; Korovaichuk, Igor

2004-01-01

Onboard radioisotope power systems being developed and planned for NASA's deep-space missions require reliable design lifetimes of up to 14 yr. The structurally critical heater head of the high-efficiency Stirling power convertor has undergone extensive computational analysis of operating temperatures, stresses, and creep resistance of the thin-walled Inconel 718 bill of material. A preliminary assessment of the effect of uncertainties in the material behavior was also performed. Creep failure resistance of the thin-walled heater head could show variation due to small deviations in the manufactured thickness and in uncertainties in operating temperature and pressure. Durability prediction and reliability of the heater head are affected by these deviations from nominal design conditions. Therefore, it is important to include the effects of these uncertainties in predicting the probability of survival of the heater head under mission loads. Furthermore, it may be possible for the heater head to experience rare incidences of small temperature excursions of short duration. These rare incidences would affect the creep strain rate and, therefore, the life. This paper addresses the effects of such rare incidences on the reliability. In addition, the sensitivities of variables affecting the reliability are quantified, and guidelines developed to improve the reliability are outlined. Heater head reliability is being quantified with data from NASA Glenn Research Center's accelerated benchmark testing program.

Pivoting-Head Wrench

NASA Technical Reports Server (NTRS)

Bradley, Glen L.

1993-01-01

Wrench ends pivot so it can be used to loosen or tighten nuts or bolts in confined spaces. One end equipped with open-end socket; other end, with double-hexagon socket. Heads pivot on pins. Pins fit tightly so heads do not flop; friction on pins sufficient to hold heads in positions until rotated intentionally.

Head Start Facilities Manual.

ERIC Educational Resources Information Center

Research Assessment Management, Inc., Silver Spring, MD.

A quality Head Start facility should provide a physical environment responsive both to the needs of the children and families served and to the needs of staff, volunteers, and community agencies that share space with Head Start. This manual is a tool for Head Start grantees and delegate agencies for assessing existing facilities, making…

A new technique to expose the hypopharyngeal space: The modified Killian's method.

PubMed

Sakai, Akihiro; Okami, Kenji; Sugimoto, Ryousuke; Ebisumoto, Koji; Yamamoto, Hikaru; Maki, Daisuke; Saito, Kosuke; Iida, Masahiro

2014-04-01

Recent remarkable progress in endoscopic technology has enabled the detection of superficial cancers that were undetectable in the past. However, even though advanced endoscopic technology can detect early lesions, it is useless unless it can provide wide exposure of an area. By modifying the Killian position, it is possible to observe a wider range of the hypopharyngeal space than is possible with conventional head positions. We report a revolutionary method that uses a new head position to widely open the hypopharynx. The technique is named "the Modified Killian's method." The patient is initially placed in the Killian position and then bent further forward from the original position (i.e., the modified Killian position). While in this position, the patient's head is turned and the Valsalva maneuver is applied. These additional maneuvers constitute the Modified Killian's method and widely expands the hypopharyngeal space. The conventional head position cannot open the hypopharyngeal space sufficiently; however, the Modified Killian's method opens the hypopharyngeal space very widely. The Modified Killian's method enables observation of the entire circumference of the hypopharyngeal space and the cervical esophageal entry. The Modified Killian's method may become an indispensable technique for observing the hypopharynx and detecting hypopharyngeal cancers. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Risk factors of recipient site infection in head and neck cancer patients undergoing pectoralis major myocutaneous flap reconstruction.

PubMed

Wang, Chao-Hsien; Wong, Yong-Kie; Wang, Ching-Ping; Wang, Chen-Chi; Jiang, Rong-San; Lai, Chih-Sheng; Liu, Shih-An

2015-11-01

The aim of this study was to investigate the factors associated with infection at the recipient site of pectoralis major myocutaneous flap (PMMF) of head and neck cancer patients. We retrospectively reviewed head and neck cancer patients who underwent PMMF reconstruction and identified those with recipient site infection. Variables of patients with and without infection were compared and associated factors were investigated by logistic regression model. A total of 478 patients were included in the final analysis and 183 patients (38.3%) developed recipient site infection. Lower margin of skin island, concurrent tracheotomy, diabetes mellitus, mandibular plate reconstruction, prior radiation, and peri-operative blood transfusion were independent factors associated with recipient site infection of PMMF. Skin island of PMMF beyond the eighth intercostal space markedly increased the risk of recipient site infection after major head and neck cancer surgery. Recognition of relevant factors associated with infection may help surgeons to identify those at risk.

Head-and-face shape variations of U.S. civilian workers

PubMed Central

Zhuang, Ziqing; Shu, Chang; Xi, Pengcheng; Bergman, Michael; Joseph, Michael

2016-01-01

The objective of this study was to quantify head-and-face shape variations of U.S. civilian workers using modern methods of shape analysis. The purpose of this study was based on previously highlighted changes in U.S. civilian worker head-and-face shape over the last few decades – touting the need for new and better fitting respirators – as well as the study's usefulness in designing more effective personal protective equipment (PPE) – specifically in the field of respirator design. The raw scan three-dimensional (3D) data for 1169 subjects were parameterized using geometry processing techniques. This process allowed the individual scans to be put in correspondence with each other in such a way that statistical shape analysis could be performed on a dense set of 3D points. This process also cleaned up the original scan data such that the noise was reduced and holes were filled in. The next step, statistical analysis of the variability of the head-and-face shape in the 3D database, was conducted using Principal Component Analysis (PCA) techniques. Through these analyses, it was shown that the space of the head-and-face shape was spanned by a small number of basis vectors. Less than 50 components explained more than 90% of the variability. Furthermore, the main mode of variations could be visualized through animating the shape changes along the PCA axes with computer software in executable form for Windows XP. The results from this study in turn could feed back into respirator design to achieve safer, more efficient product style and sizing. Future study is needed to determine the overall utility of the point cloud-based approach for the quantification of facial morphology variation and its relationship to respirator performance. PMID:23399025

Head-and-face shape variations of U.S. civilian workers.

PubMed

Zhuang, Ziqing; Shu, Chang; Xi, Pengcheng; Bergman, Michael; Joseph, Michael

2013-09-01

The objective of this study was to quantify head-and-face shape variations of U.S. civilian workers using modern methods of shape analysis. The purpose of this study was based on previously highlighted changes in U.S. civilian worker head-and-face shape over the last few decades - touting the need for new and better fitting respirators - as well as the study's usefulness in designing more effective personal protective equipment (PPE) - specifically in the field of respirator design. The raw scan three-dimensional (3D) data for 1169 subjects were parameterized using geometry processing techniques. This process allowed the individual scans to be put in correspondence with each other in such a way that statistical shape analysis could be performed on a dense set of 3D points. This process also cleaned up the original scan data such that the noise was reduced and holes were filled in. The next step, statistical analysis of the variability of the head-and-face shape in the 3D database, was conducted using Principal Component Analysis (PCA) techniques. Through these analyses, it was shown that the space of the head-and-face shape was spanned by a small number of basis vectors. Less than 50 components explained more than 90% of the variability. Furthermore, the main mode of variations could be visualized through animating the shape changes along the PCA axes with computer software in executable form for Windows XP. The results from this study in turn could feed back into respirator design to achieve safer, more efficient product style and sizing. Future study is needed to determine the overall utility of the point cloud-based approach for the quantification of facial morphology variation and its relationship to respirator performance. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Head space analysis to non-invasively distinguish between vaccinated and bovine tuberculosis-infected white-tailed deer

USDA-ARS?s Scientific Manuscript database

White-tailed deer (WTD; Odocoileus virginianus) can act as a reservoir for bovine tuberculosis (bTB), caused by Mycobacterium bovis, and can be a source of infection in cattle. Presently, no method exists to noninvasively monitor the presence of bTB in wildlife. In addition, due to similarities betw...

Optokinetic and vestibular stimulation determines the spatial orientation of negative optokinetic afternystagmus in the rabbit.

PubMed

Pettorossi, V E; Errico, P; Ferraresi, A; Barmack, N H

1999-02-15

Prolonged binocular optokinetic stimulation (OKS) in the rabbit induces a high-velocity negative optokinetic afternystagmus (OKAN II) that persists for several hours. We have taken advantage of this uniform nystagmus to study how changes in static head orientation in the pitch plane might influence the orientation of the nystagmus. After horizontal OKS, the rotation axis of the OKAN II remained almost constant in space as it was kept aligned with the gravity vector when the head was pitched by as much as 80 degrees up and 35 degrees down. Moreover, during reorientation, slow-phase eye velocity decreased according to the head pitch angle. Thereafter, we analyzed the space orientation of OKAN II after optokinetic stimulation during which the head and/or the OKS were pitched upward and downward. The rotation axis of OKAN II did not remain aligned with an earth vertical axis nor a head vertical axis, but it tended to be aligned with that of the OKS respace. The slow-phase eye velocity of OKAN II was also affected by the head pitch angle during OKS, because maximal OKAN II velocity occurred at the same head pitch angle as that during optokinetic stimulation. We suggest that OKAN II is coded in gravity-centered rather than in head-centered coordinates, but that this coordinate system may be influenced by optokinetic and vestibular stimulation. Moreover, the velocity attenuation of OKAN II seems to depend on the mismatch between the space-centered nystagmus rotation axis orientation and that of the "remembered" head-centered optokinetic pathway activated by OKS.

Multiview face detection based on position estimation over multicamera surveillance system

NASA Astrophysics Data System (ADS)

Huang, Ching-chun; Chou, Jay; Shiu, Jia-Hou; Wang, Sheng-Jyh

2012-02-01

In this paper, we propose a multi-view face detection system that locates head positions and indicates the direction of each face in 3-D space over a multi-camera surveillance system. To locate 3-D head positions, conventional methods relied on face detection in 2-D images and projected the face regions back to 3-D space for correspondence. However, the inevitable false face detection and rejection usually degrades the system performance. Instead, our system searches for the heads and face directions over the 3-D space using a sliding cube. Each searched 3-D cube is projected onto the 2-D camera views to determine the existence and direction of human faces. Moreover, a pre-process to estimate the locations of candidate targets is illustrated to speed-up the searching process over the 3-D space. In summary, our proposed method can efficiently fuse multi-camera information and suppress the ambiguity caused by detection errors. Our evaluation shows that the proposed approach can efficiently indicate the head position and face direction on real video sequences even under serious occlusion.

Otolithic and extraocular muscle proprioceptive influences on the spatial organization of the vestibulo- and cervico-ocular quick phases.

PubMed

Pettorossi, V E; Manni, E; Errico, P; Ferraresi, A; Bortolami, R

1997-03-01

The cervico-ocular reflex (COR) was studied alone or in combination with the vestibulo-ocular reflex (VOR) in the rabbit. Step stimulations of the body with respect to the fixed head induced small slow compensatory responses followed by large compensatory quick phases (QP). These responses remained aligned with the horizon at different head pitch angles. The QP reorientation in space was due to the gravity influence on the otolithic receptors. The vestibular induced QPs exhibit a similar pattern. Because of this reorientation, the reduction of the amplitude of the vestibular induced QPs, due to the addition of the COR, was maintained even at different static head positions. The electrolytic lesion of the ophthalmic branch of the trigeminal nerve deeply affected the space orientation of the COR. In particular, the cervically induced compensatory QPs of the eye ipsilateral to the lesion showed a remarkable variability of their trajectories and they lost space reorientation. These findings suggest that the coordinate system controlling the QPs is influenced by signals originating from both head position in space and eye position in the orbit.

Method and apparatus for measuring volatile compounds in an aqueous solution

DOEpatents

Gilmore, Tyler J [Pasco, WA; Cantrell, Kirk J [West Richland, WA

2002-07-16

The present invention is an improvement to the method and apparatus for measuring volatile compounds in an aqueous solution. The apparatus is a chamber with sides and two ends, where the first end is closed. The chamber contains a solution volume of the aqueous solution and a gas that is trapped within the first end of the chamber above the solution volume. The gas defines a head space within the chamber above the solution volume. The chamber may also be a cup with the second end. open and facing down and submerged in the aqueous solution so that the gas defines the head space within the cup above the solution volume. The cup can also be entirely submerged in the aqueous solution. The second end of the. chamber may be closed such that the chamber can be used while resting on a flat surface such as a bench. The improvement is a sparger for mixing the gas with the solution volume. The sparger can be a rotating element such as a propeller on a shaft or a cavitating impeller. The sparger can also be a pump and nozzle where the pump is a liquid pump and the nozzle is a liquid spray nozzle open, to the head space for spraying the solution volume into the head space of gas. The pump could also be a gas pump and the nozzle a gas nozzle submerged in the solution volume for spraying the head space gas into the solution volume.

Using Tri-Axial Accelerometers to Assess the Dynamic Control of Head Posture During Gait

NASA Technical Reports Server (NTRS)

Lawrence, John H., III

2003-01-01

Long duration spaceflight is known to cause a variety of biomedical stressors to the astronaut. One of the more functionally destabilizing effects of spaceflight involves microgravity-induced changes in vestibular or balance control. Balance control requires the integration of the vestibular, visual, and proprioceptive systems. In the microgravity environment, the normal gravity vector present on Earth no longer serves as a reference for the balance control system. Therefore, adaptive changes occur to the vestibular system to affect control of body orientation with altered, or non-present, gravity and/or proprioceptive inputs. Upon return to a gravity environment, the vestibular system must re-incorporate the gravity vector and gravity-induced proprioceptive inputs into the balance control regime. The result is often a period of postural instability, which may also be associated with space motion sickness (oscillopsia, nausea, and vertigo). Previous studies by the JSC Neuroscience group have found that returning astronauts often employ alterations in gait mechanics to maintain postural control during gait. It is believed that these gait alterations are meant to decrease the transfer of heel strike shock energy to the head, thus limiting the contradictory head and eye movements that lead to gait instability and motion sickness symptoms. We analyzed pre- and post-spaceflight tri-axial accelerometer data from the NASA/MIR long duration spaceflight missions to assess the heel to head transfer of heel strike shock energy during locomotion. Up to seven gait sessions (three preflight, four postflight) of head and shank (lower leg) accelerometer data was previously collected from six astronauts who engaged in space flights of four to six months duration. In our analysis, the heel to head transmission of shock energy was compared using peak vertical acceleration (a), peak jerk (j) ratio, and relative kinetic energy (a). A host of generalized movement variables was produced in an effort to isolate those that best highlighted vestibular adaptation due to spaceflight. Data suggest that astronauts used either head or body centered control to reduce the effects of heel strike shock on head position during normal walking at self-selected speeds. Moreover, the form of that control appears to fall under one of two categories: homeostatic or adaptive. Homeostatic control refers to tight constraint (small error) over the value of a given variable before and after spaceflight with little or no adaptive changes. Adaptive control refers to lesser constraint over a given movement variable with clear adaptation to earth gravity upon return from spaceflight. Heel strike shock absorption (ratio of heel to head peak acceleration) best-discriminated head and body centered control strategies. Further, peak jerk data was useful for illustrating pre- and postflight differences in segmental (shank versus head) movement energy. Results from kinetic energy analysis show high consistency between subjects and across test dates. Whether this result highlights a control strategy or is an artifact of approximating body segments using anthropometric tables is, at this point, unclear.

Multiple-Coil, Pulse-Induction Metal Detector

NASA Technical Reports Server (NTRS)

Lesky, Edward S.; Reid, Alan M.; Bushong, Wilton E.; Dickey, Duane P.

1988-01-01

Multiple-head, pulse-induction metal detector scans area of 72 feet squared with combination of eight detector heads, each 3 ft. square. Head includes large primary coil inducing current in smaller secondary coils. Array of eight heads enables searcher to cover large area quickly. Pulses applied to primary coil, induced in secondary coils measured to determine whether metal present within range of detector head. Detector designed for recovery of Space Shuttle debris.

Around Marshall

NASA Image and Video Library

1993-09-15

Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. Marshall SPace Flight Center (MSFC) is begirning to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models are used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup is to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability provides general visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC).

Ecology and thermal inactivation of microbes in and on interplanetary space vehicle components

NASA Technical Reports Server (NTRS)

Campbell, J. E.

1971-01-01

Data showing that 90 C was a more effective temperature than 125 C for the destruction of Bacillus subtilis var. niger when the head-space moisture was fixed at 474 micrograms H2O/ml have been confirmed and are summarized. The influence of head-space moisture at 90 C was investigated and it was observed that as the head-space moisture was increased 474 micrograms H2O/ml, there was a corresponding increase in lethality of the system. This moisture level corresponded to 100% relative humidity at 90 C, and additional water in the cans should have had no effect. A profound descrease was observed in the destruction of the organisms when additional water was added. The discontinuity observed in these data is troublesome and must be resolved as the first step in an orderly exploration of low temperature inactivation of B. subtilis var. niger.

An Experimental and Analytical Investigation of Stirling Space Power Converter Heater Head

NASA Technical Reports Server (NTRS)

Abdul-Aziz, Ali; Bartolotta, Paul; Tong, Mike; Allen, Gorden

1995-01-01

NASA has identified the Stirling power converter as a prime candidate for the next generation power system for space applications requiring 60000 hr of operation. To meet this long-term goal, several critical components of the power converter have been analyzed using advanced structural assessment methods. Perhaps the most critical component, because of its geometric complexity and operating environment, is the power converter's heater head. This report describes the life assessment of the heater head which includes the characterization of a viscoplastic material model, the thermal and structural analyses of the heater head, and the interpolation of fatigue and creep test results of a nickel-base superalloy, Udimet 720 LI (Low Inclusions), at several elevated temperatures for life prediction purposes.

Head and cervical spine postures in complete denture wearers.

PubMed

Salonen, M A; Raustia, A M; Huggare, J

1993-01-01

Signs and symptoms in the stomatognathic system and head and cervical spine postures were evaluated in 10 edentulous patients prior to renewal of their dentures, as well as immediately and six months after insertion of new dentures. Natural head posture was recorded using the fluid-level method and measured from the roentgen cephalograms. It was shown that the variables duration of edentulousness and free-way space displayed positive correlations with the dysfunction symptoms. In addition, the patients who needed oral rehabilitation the most, who received the greatest reduction in their free-way space, were seen to have raised their heads more than average. There was also an inverse correlation between the reduction of clinical dysfunction index score and cervical spine postures.

A simple and sensitive method for the determination of hydroxylamine in fresh-water samples using hypochlorite followed by gas chromatography.

PubMed

Seike, Yasushi; Fukumori, Ryoko; Senga, Yukiko; Oka, Hiroki; Fujinaga, Kaoru; Okumura, Minoru

2004-01-01

A new and simple method for the determination of hydroxylamine in environmental water, such as fresh rivers and lakes using hypochlorite, followed by its gas choromatographic detection, has been developed. A glass vial filled with sample water was sealed by a butyl-rubber stopper and aluminum cap without head-space, and then sodium hypochlorite solution was injected into the vial through a syringe to convert hydroxylamine to nitrous oxide. The head-space in the glass vial was prepared with 99.9% grade N2 using a gas-tight syringe. After the glass vial was shaken for a few minutes, nitrous oxide in the gas-phase was measured by a gas chromatograph with an electron-capture detector. The dissolved nitrous oxide in the liquid-phase was calculated according to the solubility formula. The proposed method was applied to the analysis of fresh-water samples taken from Iu river and Hii river, flowing into brackish Lakes Nakaumi and Shinji, respectively.

Historical ties between otolaryngology-head and neck surgery and aviation and space medicine.

PubMed

Alford, B R; Atkins, J H

1998-03-01

Otolaryngology-head and neck surgeons have been involved in the development of aviation and space medicine since the beginning of this century. More than 75 years ago, otolaryngologists revised the physical examination for pilots, organized "boards of medical examiners" to test pilot applicants, coined the term "flight surgeon," and helped organize the first medical research laboratories at Hazelhurst Field in New York. These laboratories were transformed in 1922 into the School of Aviation Medicine at Brooks Field, Texas, which in turn subsequently was relocated to Randolph Field, Texas. During World War II the Director of Research at the school was Colonel Paul A. Campbell, MD, an otolaryngologist. In 1959, the school moved back to Brooks Air Force Base and was renamed the Aerospace Medical Center. Since manned space flight began in the 1960s there have been many joint research efforts between principal investigators in otolaryngology-head and neck surgery and NASA. Several otolaryngology-head and neck surgeons have served or currently serve as consultants and advisors to many of NASA's standing committees. The space environment offers a new frontier for development and research in the specialty and for better understanding of vestibular function and related disorders.

State-dependent sensorimotor processing: gaze and posture stability during simulated flight in birds.

PubMed

McArthur, Kimberly L; Dickman, J David

2011-04-01

Vestibular responses play an important role in maintaining gaze and posture stability during rotational motion. Previous studies suggest that these responses are state dependent, their expression varying with the environmental and locomotor conditions of the animal. In this study, we simulated an ethologically relevant state in the laboratory to study state-dependent vestibular responses in birds. We used frontal airflow to simulate gliding flight and measured pigeons' eye, head, and tail responses to rotational motion in darkness, under both head-fixed and head-free conditions. We show that both eye and head response gains are significantly higher during flight, thus enhancing gaze and head-in-space stability. We also characterize state-specific tail responses to pitch and roll rotation that would help to maintain body-in-space orientation during flight. These results demonstrate that vestibular sensorimotor processing is not fixed but depends instead on the animal's behavioral state.

State-dependent sensorimotor processing: gaze and posture stability during simulated flight in birds

PubMed Central

McArthur, Kimberly L.

2011-01-01

Vestibular responses play an important role in maintaining gaze and posture stability during rotational motion. Previous studies suggest that these responses are state dependent, their expression varying with the environmental and locomotor conditions of the animal. In this study, we simulated an ethologically relevant state in the laboratory to study state-dependent vestibular responses in birds. We used frontal airflow to simulate gliding flight and measured pigeons′ eye, head, and tail responses to rotational motion in darkness, under both head-fixed and head-free conditions. We show that both eye and head response gains are significantly higher during flight, thus enhancing gaze and head-in-space stability. We also characterize state-specific tail responses to pitch and roll rotation that would help to maintain body-in-space orientation during flight. These results demonstrate that vestibular sensorimotor processing is not fixed but depends instead on the animal's behavioral state. PMID:21307332

Development of Head Injury Assessment Reference Values Based on NASA Injury Modeling

NASA Technical Reports Server (NTRS)

Somers, Jeffrey T.; Melvin, John W.; Tabiei, Ala; Lawrence, Charles; Ploutz-Snyder, Robert; Granderson, Bradley; Feiveson, Alan; Gernhardt, Michael; Patalak, John

2011-01-01

NASA is developing a new capsule-based, crewed vehicle that will land in the ocean, and the space agency desires to reduce the risk of injury from impact during these landings. Because landing impact occurs for each flight and the crew might need to perform egress tasks, current injury assessment reference values (IARV) were deemed insufficient. Because NASCAR occupant restraint systems are more effective than the systems used to determine the current IARVs and are similar to NASA s proposed restraint system, an analysis of NASCAR impacts was performed to develop new IARVs that may be more relevant to NASA s context of vehicle landing operations. Head IARVs associated with race car impacts were investigated by completing a detailed analysis of all of the 2002-2008 NASCAR impact data. Specific inclusion and exclusion criteria were used to select 4071 impacts from the 4015 recorder files provided (each file could contain multiple impact events). Of the 4071 accepted impacts, 274 were selected for numerical simulation using a custom NASCAR restraint system and Humanetics Hybrid-III 50th percentile numerical dummy model in LS-DYNA. Injury had occurred in 32 of the 274 selected impacts, and 27 of those injuries involved the head. A majority of the head injuries were mild concussions with or without brief loss of consciousness. The 242 non-injury impacts were randomly selected and representative of the range of crash dynamics present in the total set of 4071 impacts. Head dynamics data (head translational acceleration, translational change in velocity, rotational acceleration, rotational velocity, HIC-15, HIC-36, and the Head 3ms clip) were filtered according to SAE J211 specifications and then transformed to a log scale. The probability of head injury was estimated using a separate logistic regression analysis for each log-transformed predictor candidate. Using the log transformation constrains the estimated probability of injury to become negligible as IARVs approach zero. For the parameters head translational acceleration, head translational velocity change, head rotational acceleration, HIC-15, and HIC-36, conservative values (in the lower 95% confidence interval) that gave rise to a 5% risk of any injury occurring were estimated as 40.0 G, 7.9 m/s, 2200 rad/s2, 98.4, and 77.4 respectively. Because NASA is interested in the consequence of any particular injury on the ability of the crew to perform egress tasks, the head injuries that occurred in the NASCAR dataset were classified according to a NASA-developed scale (Classes I - III) for operationally relevant injuries, which classifies injuries on the basis of their operational significance. Additional analysis of the data was performed to determine the probability of each injury class occurring, and this was estimated using an ordered probit model. For head translational acceleration, head translational velocity change, head rotational acceleration, head rotational velocity, HIC-36, and head 3ms clip, conservative values of IARVs that produced a 5% risk of Class II injury were estimated as 50.7 G, 9.5 m/s, 2863 rad/s2, 11.0 rad/s, 30.3, and 46.4 G respectively. The results indicate that head IARVs developed from the NASCAR dataset may be useful to protect crews during landing impact.

Stabilization of gaze during circular locomotion in light. I. Compensatory head and eye nystagmus in the running monkey

NASA Technical Reports Server (NTRS)

Solomon, D.; Cohen, B.

1992-01-01

1. A rhesus and cynomolgus monkey were trained to run around the perimeter of a circular platform in light. We call this "circular locomotion" because forward motion had an angular component. Head and body velocity in space were recorded with angular rate sensors and eye movements with electrooculography (EOG). From these measurements we derived signals related to the angular velocity of the eyes in the head (Eh), of the head on the body (Hb), of gaze on the body (Gb), of the body in space (Bs), of gaze in space (Gs), and of the gain of gaze (Gb/Bs). 2. The monkeys had continuous compensatory nystagmus of the head and eyes while running, which stabilized Gs during the slow phases. The eyes established and maintained compensatory gaze velocities at the beginning and end of the slow phases. The head contributed to gaze velocity during the middle of the slow phases. Slow phase Gb was as high as 250 degrees/s, and targets were fixed for gaze angles as large as 90-140 degrees. 3. Properties of the visual surround affected both the gain and strategy of gaze compensation in the one monkey tested. Gains of Eh ranged from 0.3 to 1.1 during compensatory gaze nystagmus. Gains of Hb varied around 0.3 (0.2-0.7), building to a maximum as Eh dropped while running past sectors of interest. Consistent with predictions, gaze gains varied from below to above unity, when translational and angular body movements with regard to the target were in opposite or the same directions, respectively. 4. Gaze moved in saccadic shifts in the direction of running during quick phases. Most head quick phases were small, and at times the head only paused during an eye quick phase. Eye quick phases were larger, ranging up to 60 degrees. This is larger than quick phases during passive rotation or saccades made with the head fixed. 5. These data indicate that head and eye nystagmus are natural phenomena that support gaze compensation during locomotion. Despite differential utilization of the head and eyes in various conditions, Gb compensated for Bs. There are various frames of reference in which an estimate of angular velocity that drives the head and eyes could be based. We infer that body in space velocity (Bs) is likely to be represented centrally to provide this signal.

Poster Session

NASA Technical Reports Server (NTRS)

1997-01-01

In this session, Poster Session, the discussion focuses on the following topics: Development of correlative measures for the assessment of attention and memory; Biodynamical Responses of the Crewmember Head/Neck System During Emergence Ejection; Fecundation in the Sky, a Ten Years Old Experiment in Microgravity; A Modified Botex Incubator as a Transport System For Developing Crickets into Space; Chromosomal Aberrations in Peripheral Lymphocytes of Cosmonauts and Astronauts after Space Flights; Method for Establishing Long term Bone Marrow; Cultures Under Microgravity Conditions Reproduction Under Simulated Weightlessness --Mammalian in vivo Experiments Under Suspension; Towards Human Movement Analysis Without the Use of Markers; Habitability Requirements For a Cogent Mars Mission; The Saucer Concept for Space Habitats; New Way In Modeling the Growth of the Organism; The Fractionation of Hydrogen and Oxygen Stable Isotopes By Life Support Systems of Space Station "MIR"; and Effect of Space Flight on Neutrophil Function.

Space plasma branch at NRL

NASA Astrophysics Data System (ADS)

The Naval Research Laboratory (Washington, D.C.) formed the Space Plasma Branch within its Plasma Physics Division on July 1. Vithal Patel, former Program Director of Magnetospheric Physics, National Science Foundation, also joined NRL on the same date as Associate Superintendent of the Plasma Physics Division. Barret Ripin is head of the newly organized branch. The Space Plasma branch will do basic and applied space plasma research using a multidisciplinary approach. It consolidates traditional rocket and satellite space experiments, space plasma theory and computation, with laboratory space-related experiments. About 40 research scientists, postdoctoral fellows, engineers, and technicians are divided among its five sections. The Theory and Computation sections are led by Joseph Huba and Joel Fedder, the Space Experiments section is led by Paul Rodriguez, and the Pharos Laser Facility and Laser Experiments sections are headed by Charles Manka and Jacob Grun.

Current concepts of space flight induced changes in hormonal control of fluid and electrolyte metabolism

NASA Technical Reports Server (NTRS)

Leach, C. S.; Johnson, P. C.; Suki, W. N.

1983-01-01

A systematic analysis of body fluid and renal dynamics during simulated space flight (head-down bedrest) was undertaken to increase understanding of the physiologic effects of acute cephalad fluid shifts. The earliest effects were increases in central venous pressure and decreases in plasma aldosterone, epinephrine and norepinephrine and glomerular filtration rate, 2 h after the beginning of bedrest. Decreases in plasma angiotensin I at 6 h may have resulted from the increased effective pressure and decreased sympathetic activity seen earlier in bedrest. The early decrease in aldosterone and ADH is thought to contribute to an increase, by 6 h, in urinary excretion of salt and water. Fluid and electrolyte losses occur during space flight, and analysis of body fluids from Space Shuttle crewmembers has indicated that conservation of these substances is begun almost immediately upon cessation of weightlessness. Operational medicine measures to counteract dehydration and electrolyte loss resulted in a less extreme physiologic response to the flight.

Eddy-Current Detection of Weak Bolt Heads

NASA Technical Reports Server (NTRS)

Messina, C. P.

1987-01-01

Electronic test identifies flawed units passing hardness tests. Eddy-current test detects weakness in head-to-shank junctions of 1/4-28 cup-washer lock bolts. Developed for alloy A286 steel bolts in Space Shuttle main engine fuel turbo-pump. Test examines full volume of head, including head-to-shank transition and nondestructively screens out potentially defective units. Test adapts to any other alloys.

14 CFR 97.5 - Bearings, courses, tracks, headings, radials, miles.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., radials, miles. 97.5 Section 97.5 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Bearings, courses, tracks, headings, radials, miles. (a) All bearings, courses, tracks, headings, and... visibility values are stated in statute miles. All other mileages are stated in nautical miles. [Doc. No. 561...

14 CFR 97.5 - Bearings, courses, tracks, headings, radials, miles.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., radials, miles. 97.5 Section 97.5 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Bearings, courses, tracks, headings, radials, miles. (a) All bearings, courses, tracks, headings, and... visibility values are stated in statute miles. All other mileages are stated in nautical miles. [Doc. No. 561...

14 CFR 97.5 - Bearings, courses, tracks, headings, radials, miles.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., radials, miles. 97.5 Section 97.5 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Bearings, courses, tracks, headings, radials, miles. (a) All bearings, courses, tracks, headings, and... visibility values are stated in statute miles. All other mileages are stated in nautical miles. [Doc. No. 561...

14 CFR 97.5 - Bearings, courses, tracks, headings, radials, miles.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., radials, miles. 97.5 Section 97.5 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Bearings, courses, tracks, headings, radials, miles. (a) All bearings, courses, tracks, headings, and... visibility values are stated in statute miles. All other mileages are stated in nautical miles. [Doc. No. 561...

Structural Benchmark Testing for Stirling Convertor Heater Heads

NASA Technical Reports Server (NTRS)

Krause, David L.; Kalluri, Sreeramesh; Bowman, Randy R.

2007-01-01

The National Aeronautics and Space Administration (NASA) has identified high efficiency Stirling technology for potential use on long duration Space Science missions such as Mars rovers, deep space missions, and lunar applications. For the long life times required, a structurally significant design limit for the Stirling convertor heater head is creep deformation induced even under relatively low stress levels at high material temperatures. Conventional investigations of creep behavior adequately rely on experimental results from uniaxial creep specimens, and much creep data is available for the proposed Inconel-718 (IN-718) and MarM-247 nickel-based superalloy materials of construction. However, very little experimental creep information is available that directly applies to the atypical thin walls, the specific microstructures, and the low stress levels. In addition, the geometry and loading conditions apply multiaxial stress states on the heater head components, far from the conditions of uniaxial testing. For these reasons, experimental benchmark testing is underway to aid in accurately assessing the durability of Stirling heater heads. The investigation supplements uniaxial creep testing with pneumatic testing of heater head test articles at elevated temperatures and with stress levels ranging from one to seven times design stresses. This paper presents experimental methods, results, post-test microstructural analyses, and conclusions for both accelerated and non-accelerated tests. The Stirling projects use the results to calibrate deterministic and probabilistic analytical creep models of the heater heads to predict their life times.

Around Marshall

NASA Image and Video Library

1993-09-15

Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. The Marshall Space Flight Centerr (MSFC) in Huntsville, Alabama began to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models were used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup was to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability provided general visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC). The X-34 program was cancelled in 2001.

Around Marshall

NASA Image and Video Library

1993-09-15

Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. The Marshall Space Flight Center (MSFC) in Huntsville, Alabama began to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models were used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup was to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability providedgeneral visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC). The X-34 program was cancelled in 2001.

Computer Applications and Virtual Environments (CAVE)

NASA Technical Reports Server (NTRS)

1993-01-01

Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. Marshall SPace Flight Center (MSFC) is begirning to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models are used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup is to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability provides general visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC).

ComputerApplications and Virtual Environments (CAVE)

NASA Technical Reports Server (NTRS)

1993-01-01

Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. The Marshall Space Flight Center (MSFC) in Huntsville, Alabama began to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models were used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup was to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability providedgeneral visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC). The X-34 program was cancelled in 2001.

ComputerApplications and Virtual Environments (CAVE)

NASA Technical Reports Server (NTRS)

1993-01-01

Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. The Marshall Space Flight Centerr (MSFC) in Huntsville, Alabama began to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models were used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup was to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability provided general visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC). The X-34 program was cancelled in 2001.

Around Marshall

NASA Image and Video Library

2003-01-16

After four decades of contribution to America's space program, George Hopson, manager of the Space Shuttle Main Engine Project at Marshall Space Flight Center, accepted NASA's Distinguished Service Medal. Awarded to those who, by distinguished ability or courage, have made a personal contribution to the NASA mission, NASA's Distinguished Service Medal is the highest honor NASA confers. Hopson's contributions to America's space program include work on the country's first space station, Skylab; the world's first reusable space vehicle, the Space Shuttle; and the International Space Station. Hopson joined NASA's Marshall team as chief of the Fluid and Thermal Systems Branch in the Propulsion Division in 1962, and later served as chief of the Engineering Analysis Division of the Structures and Propulsion Laboratory. In 1979, he was named director of Marshall's Systems Dynamics Laboratory. In 1981, he was chosen to head the Center's Systems Analysis and Integration. Seven years later, in 1988, Hopson was appointed associate director for Space Transportation Systems and one year later became the manager of the Space Station Projects Office at Marshall. In 1994, Hopson was selected as deputy director for Space Systems in the Science and Engineering Directorate at Marshall where he supervised the Chief Engineering Offices of both marned and unmanned space systems. He was named manager of the Space Shuttle Main Engine Project in 1997. In addition to the Distinguished Service Medal, Hopson has also been recognized with the NASA Outstanding Leadership Medal and NASA's Exceptional Service Medal.

Femoroacetabular Impingement

DTIC Science & Technology

2008-04-01

the abnormal morphology of the femoral head indicative of FAI. Prominent osteophyte formation can be seen bilaterally at the femoral head-neck...marked joint space loss of the left hip which predominantly involves the superolateral aspect of the joint (Figs. 1B and 2). Subchondral sclerosis...B). Close up view of the left hip from Fig. 1A. Superolateral joint space loss, subchondral sclerosis, cystic changes of the anterolateral femoral

Uncertainty in the modelling of spatial and temporal patterns of shallow groundwater flow paths: The role of geological and hydrological site information

NASA Astrophysics Data System (ADS)

Woodward, Simon J. R.; Wöhling, Thomas; Stenger, Roland

2016-03-01

Understanding the hydrological and hydrogeochemical responses of hillslopes and other small scale groundwater systems requires mapping the velocity and direction of groundwater flow relative to the controlling subsurface material features. Since point observations of subsurface materials and groundwater head are often the basis for modelling these complex, dynamic, three-dimensional systems, considerable uncertainties are inevitable, but are rarely assessed. This study explored whether piezometric head data measured at high spatial and temporal resolution over six years at a hillslope research site provided sufficient information to determine the flow paths that transfer nitrate leached from the soil zone through the shallow saturated zone into a nearby wetland and stream. Transient groundwater flow paths were modelled using MODFLOW and MODPATH, with spatial patterns of hydraulic conductivity in the three material layers at the site being estimated by regularised pilot point calibration using PEST, constrained by slug test estimates of saturated hydraulic conductivity at several locations. Subsequent Null Space Monte Carlo uncertainty analysis showed that this data was not sufficient to definitively determine the spatial pattern of hydraulic conductivity at the site, although modelled water table dynamics matched the measured heads with acceptable accuracy in space and time. Particle tracking analysis predicted that the saturated flow direction was similar throughout the year as the water table rose and fell, but was not aligned with either the ground surface or subsurface material contours; indeed the subsurface material layers, having relatively similar hydraulic properties, appeared to have little effect on saturated water flow at the site. Flow path uncertainty analysis showed that, while accurate flow path direction or velocity could not be determined on the basis of the available head and slug test data alone, the origin of well water samples relative to the material layers and site contour could still be broadly deduced. This study highlights both the challenge of collecting suitably informative field data with which to characterise subsurface hydrology, and the power of modern calibration and uncertainty modelling techniques to assess flow path uncertainty in hillslopes and other small scale systems.

Analysis by NASA's VESGEN Software of Retinal Blood Vessels in Human Subjects Undergoing Head-Down Tilt During 70-Day Bed Rest

NASA Technical Reports Server (NTRS)

Vyas, Ruchi J.; Murray, Matthew C.; Predovic, Marina; Lim, Shiyin; Askin, Kayleigh N.; Vizzeri, Gianmarco; Taibbi, Giovanni; Mason, Sara Stroble; Zanello, Susana B.; Young, Millenia;

Expedition 53 Landing Preparations

NASA Image and Video Library

2017-12-12

Deputy Head of the Gagarin Cosmonaut Training Center and cosmonaut Yuri Malenchenko, left, Head of the Search-and-Rescue Department of Rosaviatsiya (Russian Federal Air Transport Agency) Aleksey N. Lukiyanov, second from left, and other Russian Search and Recovery personnel are seen during a readiness review for the landing of Expedition 53 Commander Randy Bresnik of NASA and Flight Engineers Paolo Nespoli of ESA (European Space Agency) and Sergey Ryazanskiy of the Russian space agency Roscosmos Tuesday, Dec. 12, 2017. Bresnik, Nespoli and Ryazanskiy are returning after 139 days in space where they served as members of the Expedition 52 and 53 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

[The influence of space flight factors on the growth and development of super dwarf wheat cultivated in greenhouse Svet

NASA Technical Reports Server (NTRS)

Levinskikh, M. A.; Sychev, V. N.; Derendiaeva, T. A.; Signalova, O. B.; Salisbury, F. B.; Campbell, W. F.; Babenheim, D.

1999-01-01

In 1996-1997 an experiment with super dwarf wheat (Greenhouse-2) was made aboard the orbital complex MIR as a part of the MIR-NASA space science program. The article deals with the main production and morphometric characteristics of plants that completed their vegetation cycle in the space flight. Lengths of the whole cycle of vegetation and its individual stages were essentially same as in ground control experiments. Dry mass of one plants equal, the number of headed shoots was in 2.7 times less in the flight harvest as compared with the control. The height of shoots was reduced by one half. No seeds were found in the heads formed in space. The architecture of heads was substantially different from what had been observed in the preceeding ground control experiments: mass of the heads was halved and lengths of inflorescence and palea awn shortened. The number of spikelets in a head reduced up to 8-10 vs. 13-14 in the controls, whereas the number of florets per a spikelet averaged 5 vs. 3 in the controls. The experiments showed that mainly the most profound changes in the productive and morphometric parameters of the super dwarf wheat plants were largely caused by the phytotoxic effects of ethylene rather than spaceflight specific factors as its concentrations in the MIR air amount to 0.3-1.8 mg/m3.

Space-to-Ground: Back to Earth: 12/15/2017

NASA Image and Video Library

2017-12-15

Expedition 53 crewmembers return to Earth, while the SpaceX Dragon heads to orbit...and how does a body first react to space? NASA's Space to Ground is your weekly update on what's happening aboard the International Space Station.

Closeup detail of the jackstand head and the attach mechanism ...

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

Close-up detail of the jack-stand head and the attach mechanism connection to the hoist attach point on the starboard forward fuselage of the Orbiter Discovery. Note the profile of the wing intersection with the fuselage and the payload bay door in an open position with the strongback support structure attached. This view was taken from a service platform in the Orbiter Processing Facility at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Small Stirling dynamic isotope power system for robotic space missions

NASA Technical Reports Server (NTRS)

Bents, D. J.

1992-01-01

The design of a multihundred-watt Dynamic Isotope Power System (DIPS), based on the U.S. Department of Energy (DOE) General Purpose Heat Source (GPHS) and small (multihundred-watt) free-piston Stirling engine (FPSE), is being pursued as a potential lower cost alternative to radioisotope thermoelectric generators (RTG's). The design is targeted at the power needs of future unmanned deep space and planetary surface exploration missions ranging from scientific probes to Space Exploration Initiative precursor missions. Power level for these missions is less than a kilowatt. The incentive for any dynamic system is that it can save fuel and reduce costs and radiological hazard. Unlike DIPS based on turbomachinery conversion (e.g. Brayton), this small Stirling DIPS can be advantageously scaled to multihundred-watt unit size while preserving size and mass competitiveness with RTG's. Stirling conversion extends the competitive range for dynamic systems down to a few hundred watts--a power level not previously considered for dynamic systems. The challenge for Stirling conversion will be to demonstrate reliability and life similar to RTG experience. Since the competitive potential of FPSE as an isotope converter was first identified, work has focused on feasibility of directly integrating GPHS with the Stirling heater head. Thermal modeling of various radiatively coupled heat source/heater head geometries has been performed using data furnished by the developers of FPSE and GPHS. The analysis indicates that, for the 1050 K heater head configurations considered, GPHS fuel clad temperatures remain within acceptable operating limits. Based on these results, preliminary characterizations of multihundred-watt units have been established.

A study to evaluate STS heads-up ascent trajectory performance employing a minimum-Hamiltonian optimization strategy

NASA Technical Reports Server (NTRS)

Sinha, Sujit

1988-01-01

A study was conducted to evaluate the performance implications of a heads-up ascent flight design for the Space Transportation System, as compared to the current heads-down flight mode. The procedure involved the use of the Minimum Hamiltonian Ascent Shuttle Trajectory Evaluation Program, which is a three-degree-of-freedom moment balance simulation of shuttle ascent. A minimum-Hamiltonian optimization strategy was employed to maximize injection weight as a function of maximum dynamic pressure constraint and Solid Rocket Motor burnrate. Performance Reference Mission Four trajectory groundrules were used for consistency. The major conclusions are that for heads-up ascent and a mission nominal design maximum dynamic pressure value of 680 psf, the optimum solid motor burnrate is 0.394 ips, which produces a performance enhancement of 4293 lbm relative to the baseline heads-down ascent, with 0.368 ips burnrate solid motors and a 680 psf dynamic pressure constraint. However, no performance advantage exists for heads-up flight if the current Solid Rocket Motor target burnrate of 0.368 ips is used. The advantage of heads-up ascent flight employing the current burnrate is that Space Shuttle Main Engine throttling for dynamic pressure control is not necessary.

Stirling Space Engine Program. Volume 2; Appendixes A, B, C and D

NASA Technical Reports Server (NTRS)

Dhar, Manmohan

1999-01-01

The objective of this program was to develop the technology necessary for operating Stirling power converters in a space environment and to demonstrate this technology in full-scale engine tests. Volume 2 of the report includes the following appendices: Appendix A: Heater Head Development (Starfish Heater Head Program, 1/10th Segment and Full-Scale Heat Pipes, and Sodium Filling and Processing); Appendix B: Component Test Power Converter (CTPC) Component Development (High-temperature Organic Materials, Heat Exchanger Fabrication, Beryllium Issues, Sodium Issues, Wear Couple Tests, Pressure Boundary Penetrations, Heating System Heaters, and Cooler Flow Test); Appendix C: Udimet Testing (Selection of the Reference Material for the Space Stirling Engine Heater Head, Udimet 720LI Creep Test Result Update, Final Summary of Space Stirling Endurance Engine Udimet 720L1 Fatigue Testing Results, Udimet 720l1 Weld Development Summary, and Udimet 720L1 Creep Test Final Results Summary), and Appendix D: CTPC Component Development Photos.

Mouse spermatozoa with higher fertilization rates have thinner nuclei

PubMed Central

Ikawa, Masahito

2017-01-01

Background Although spermatozoa with normal morphology are assumed to have uniform fertilization ability, recent data show that even normal spermatozoa have considerable variation in their head shape which is associated with differences in fertilization ability. Appropriate quantitative indicators for good sperm morphology, however, remain unidentified. Methods Therefore, in an effort to identify such an indicator, we compared the nuclear contour of normal mouse spermatozoa by quantitative multivariate analysis using elliptic Fourier descriptors combined with principal component analysis. The spermatozoa were obtained from different strains and collection sites which have been shown to be associated with different fertilization abilities. Results We found that the head was 5.7% thinner in spermatozoa from the B6D2F1 (BDF1) strain, known to have a higher fertilization rate, than in those from the C57BL/6N (B6N) strain, which has a lower fertilization rate. Moreover, zona-penetrated spermatozoa in the perivitelline space consistently had 5.4% thinner heads than those isolated from the epididymis before ejaculation. The aspect ratio, which represents the sperm head thinness, uniquely distinguished these sperm populations, confirming its validity as a morphological indicator. Discussion Because aspect ratio has also been shown to characterize human spermatozoa, this unique morphometric indicator might be applicable to compare normal spermatozoa among multiple patients, which will greatly facilitate and enhance current reproductive technologies. PMID:29038763

Development and Efficacy Testing of Next Generation Cyanide Antidotes

DTIC Science & Technology

2013-10-01

Preparation of mDMTS A-2.2. HPLC method for DMTS determination in Micelles A-2.3. Head-space solid phase micro-extraction- gas chromatography -mass...Simultaneous determination of cyanide and thiocyanate in plasma by chemical ionization gas chromatography mass-spectrometry (CI-GC-MS). Analytical and...min. Peak integration was performed using Star Chromatography Workstation Version 6.20. A-2.3. Head-space solid phase micro-extraction- gas

Structural Benchmark Creep Testing for the Advanced Stirling Convertor Heater Head

NASA Technical Reports Server (NTRS)

Krause, David L.; Kalluri, Sreeramesh; Bowman, Randy R.; Shah, Ashwin R.

2008-01-01

The National Aeronautics and Space Administration (NASA) has identified the high efficiency Advanced Stirling Radioisotope Generator (ASRG) as a candidate power source for use on long duration Science missions such as lunar applications, Mars rovers, and deep space missions. For the inherent long life times required, a structurally significant design limit for the heater head component of the ASRG Advanced Stirling Convertor (ASC) is creep deformation induced at low stress levels and high temperatures. Demonstrating proof of adequate margins on creep deformation and rupture for the operating conditions and the MarM-247 material of construction is a challenge that the NASA Glenn Research Center is addressing. The combined analytical and experimental program ensures integrity and high reliability of the heater head for its 17-year design life. The life assessment approach starts with an extensive series of uniaxial creep tests on thin MarM-247 specimens that comprise the same chemistry, microstructure, and heat treatment processing as the heater head itself. This effort addresses a scarcity of openly available creep properties for the material as well as for the virtual absence of understanding of the effect on creep properties due to very thin walls, fine grains, low stress levels, and high-temperature fabrication steps. The approach continues with a considerable analytical effort, both deterministically to evaluate the median creep life using nonlinear finite element analysis, and probabilistically to calculate the heater head s reliability to a higher degree. Finally, the approach includes a substantial structural benchmark creep testing activity to calibrate and validate the analytical work. This last element provides high fidelity testing of prototypical heater head test articles; the testing includes the relevant material issues and the essential multiaxial stress state, and applies prototypical and accelerated temperature profiles for timely results in a highly controlled laboratory environment. This paper focuses on the last element and presents a preliminary methodology for creep rate prediction, the experimental methods, test challenges, and results from benchmark testing of a trial MarM-247 heater head test article. The results compare favorably with the analytical strain predictions. A description of other test findings is provided, and recommendations for future test procedures are suggested. The manuscript concludes with describing the potential impact of the heater head creep life assessment and benchmark testing effort on the ASC program.

Experimental Creep Life Assessment for the Advanced Stirling Convertor Heater Head

NASA Technical Reports Server (NTRS)

Krause, David L.; Kalluri, Sreeramesh; Shah, Ashwin R.; Korovaichuk, Igor

2010-01-01

The United States Department of Energy is planning to develop the Advanced Stirling Radioisotope Generator (ASRG) for the National Aeronautics and Space Administration (NASA) for potential use on future space missions. The ASRG provides substantial efficiency and specific power improvements over radioisotope power systems of heritage designs. The ASRG would use General Purpose Heat Source modules as energy sources and the free-piston Advanced Stirling Convertor (ASC) to convert heat into electrical energy. Lockheed Martin Corporation of Valley Forge, Pennsylvania, is integrating the ASRG systems, and Sunpower, Inc., of Athens, Ohio, is designing and building the ASC. NASA Glenn Research Center of Cleveland, Ohio, manages the Sunpower contract and provides technology development in several areas for the ASC. One area is reliability assessment for the ASC heater head, a critical pressure vessel within which heat is converted into mechanical oscillation of a displacer piston. For high system efficiency, the ASC heater head operates at very high temperature (850 C) and therefore is fabricated from an advanced heat-resistant nickel-based superalloy Microcast MarM-247. Since use of MarM-247 in a thin-walled pressure vessel is atypical, much effort is required to assure that the system will operate reliably for its design life of 17 years. One life-limiting structural response for this application is creep; creep deformation is the accumulation of time-dependent inelastic strain under sustained loading over time. If allowed to progress, the deformation eventually results in creep rupture. Since creep material properties are not available in the open literature, a detailed creep life assessment of the ASC heater head effort is underway. This paper presents an overview of that creep life assessment approach, including the reliability-based creep criteria developed from coupon testing, and the associated heater head deterministic and probabilistic analyses. The approach also includes direct benchmark experimental creep assessment. This element provides high-fidelity creep testing of prototypical heater head test articles to investigate the relevant material issues and multiaxial stress state. Benchmark testing provides required data to evaluate the complex life assessment methodology and to validate that analysis. Results from current benchmark heater head tests and newly developed experimental methods are presented. In the concluding remarks, the test results are shown to compare favorably with the creep strain predictions and are the first experimental evidence for a robust ASC heater head creep life.

Visual–Motor Transformations Within Frontal Eye Fields During Head-Unrestrained Gaze Shifts in the Monkey

PubMed Central

Sajad, Amirsaman; Sadeh, Morteza; Keith, Gerald P.; Yan, Xiaogang; Wang, Hongying; Crawford, John Douglas

2015-01-01

A fundamental question in sensorimotor control concerns the transformation of spatial signals from the retina into eye and head motor commands required for accurate gaze shifts. Here, we investigated these transformations by identifying the spatial codes embedded in visually evoked and movement-related responses in the frontal eye fields (FEFs) during head-unrestrained gaze shifts. Monkeys made delayed gaze shifts to the remembered location of briefly presented visual stimuli, with delay serving to dissociate visual and movement responses. A statistical analysis of nonparametric model fits to response field data from 57 neurons (38 with visual and 49 with movement activities) eliminated most effector-specific, head-fixed, and space-fixed models, but confirmed the dominance of eye-centered codes observed in head-restrained studies. More importantly, the visual response encoded target location, whereas the movement response mainly encoded the final position of the imminent gaze shift (including gaze errors). This spatiotemporal distinction between target and gaze coding was present not only at the population level, but even at the single-cell level. We propose that an imperfect visual–motor transformation occurs during the brief memory interval between perception and action, and further transformations from the FEF's eye-centered gaze motor code to effector-specific codes in motor frames occur downstream in the subcortical areas. PMID:25491118

Design and motion control of bioinspired humanoid robot head from servo motors toward artificial muscles

NASA Astrophysics Data System (ADS)

Almubarak, Yara; Tadesse, Yonas

2017-04-01

The potential applications of humanoid robots in social environments, motivates researchers to design, and control biomimetic humanoid robots. Generally, people are more interested to interact with robots that have similar attributes and movements to humans. The head is one of most important part of any social robot. Currently, most humanoid heads use electrical motors, pneumatic actuators, and shape memory alloy (SMA) actuators for actuation. Electrical and pneumatic actuators take most of the space and would cause unsmooth motions. SMAs are expensive to use in humanoids. Recently, in many robotic projects, Twisted and Coiled Polymer (TCP) artificial muscles are used as linear actuators which take up little space compared to the motors. In this paper, we will demonstrate the designing process and motion control of a robotic head with TCP muscles. Servo motors and artificial muscles are used for actuating the head motion, which have been controlled by a cost efficient ARM Cortex-M7 based development board. A complete comparison between the two actuators is presented.

Inertial processing of vestibulo-ocular signals

NASA Technical Reports Server (NTRS)

Hess, B. J.; Angelaki, D. E.

1999-01-01

New evidence for a central resolution of gravito-inertial signals has been recently obtained by analyzing the properties of the vestibulo-ocular reflex (VOR) in response to combined lateral translations and roll tilts of the head. It is found that the VOR generates robust compensatory horizontal eye movements independent of whether or not the interaural translatory acceleration component is canceled out by a gravitational acceleration component due to simultaneous roll-tilt. This response property of the VOR depends on functional semicircular canals, suggesting that the brain uses both otolith and semicircular canal signals to estimate head motion relative to inertial space. Vestibular information about dynamic head attitude relative to gravity is the basis for computing head (and body) angular velocity relative to inertial space. Available evidence suggests that the inertial vestibular system controls both head attitude and velocity with respect to a gravity-centered reference frame. The basic computational principles underlying the inertial processing of otolith and semicircular canal afferent signals are outlined.

Characterizing head motion in three planes during combined visual and base of support disturbances in healthy and visually sensitive subjects.

PubMed

Keshner, E A; Dhaher, Y

2008-07-01

Multiplanar environmental motion could generate head instability, particularly if the visual surround moves in planes orthogonal to a physical disturbance. We combined sagittal plane surface translations with visual field disturbances in 12 healthy (29-31 years) and 3 visually sensitive (27-57 years) adults. Center of pressure (COP), peak head angles, and RMS values of head motion were calculated and a three-dimensional model of joint motion was developed to examine gross head motion in three planes. We found that subjects standing quietly in front of a visual scene translating in the sagittal plane produced significantly greater (p<0.003) head motion in yaw than when on a translating platform. However, when the platform was translated in the dark or with a visual scene rotating in roll, head motion orthogonal to the plane of platform motion significantly increased (p<0.02). Visually sensitive subjects having no history of vestibular disorder produced large, delayed compensatory head motion. Orthogonal head motions were significantly greater in visually sensitive than in healthy subjects in the dark (p<0.05) and with a stationary scene (p<0.01). We concluded that motion of the visual field could modify compensatory response kinematics of a freely moving head in planes orthogonal to the direction of a physical perturbation. These results suggest that the mechanisms controlling head orientation in space are distinct from those that control trunk orientation in space. These behaviors would have been missed if only COP data were considered. Data suggest that rehabilitation training can be enhanced by combining visual and mechanical perturbation paradigms.

Morphometric magnetic resonance imaging and genetic testing in cerebellar abiotrophy in Arabian horses

PubMed Central

2013-01-01

Background Cerebellar abiotrophy (CA) is a rare but significant disease in Arabian horses caused by progressive death of the Purkinje cells resulting in cerebellar ataxia characterized by a typical head tremor, jerky head movements and lack of menace response. The specific role of magnetic resonance imaging (MRI) to support clinical diagnosis has been discussed. However, as yet MR imaging has only been described in one equine CA case. The role of MR morphometry in this regard is currently unknown. Due to the hereditary nature of the disease, genetic testing can support the diagnosis of CA. Therefore, the objective of this study was to perform MR morphometric analysis and genetic testing in four CA-affected Arabian horses and one German Riding Pony with purebred Arabian bloodlines in the third generation. Results CA was diagnosed pathohistologically in the five affected horses (2 months - 3 years) supported by clinical signs, necropsy, and genetic testing which confirmed the TOE1:g.2171G>A SNP genotype A/A in all CA-affected horses. On MR images morphometric analysis of the relative cerebellar size and relative cerebellar cerebrospinal fluid (CSF) space were compared to control images of 15 unaffected horses. It was demonstrated that in MR morphometric analyses, CA affected horses displayed a relatively smaller cerebellum compared to the entire brain mass than control animals (P = 0.0088). The relative cerebellar CSF space was larger in affected horses (P = 0.0017). Using a cut off value of 11.0% for relative cerebellar CSF space, the parameter differentiated between CA-affected horses and controls with a sensitivity of 100% and a specificity of 93.3%. Conclusions In conclusion, morphometric MRI and genetic analysis could be helpful to support the diagnosis of CA in vivo. PMID:23702154

A study of multiplex data bus techniques for the space shuttle

NASA Technical Reports Server (NTRS)

Kearney, R. J.; Kalange, M. A.

1972-01-01

A comprehensive technology base for the design of a multiplexed data bus subsystem is provided. Extensive analyses, both analytical and empirical, were performed. Subjects covered are classified under the following headings: requirements identification and analysis; transmission media studies; signal design and detection studies; synchronization, timing, and control studies; user-subsystem interface studies; operational reliability analyses; design of candidate data bus configurations; and evaluation of candidate data bus designs.

Rocketdyne automated dynamics data analysis and management system

NASA Technical Reports Server (NTRS)

Tarn, Robert B.

1988-01-01

An automated dynamics data analysis and management systems implemented on a DEC VAX minicomputer cluster is described. Multichannel acquisition, Fast Fourier Transformation analysis, and an online database have significantly improved the analysis of wideband transducer responses from Space Shuttle Main Engine testing. Leakage error correction to recover sinusoid amplitudes and correct for frequency slewing is described. The phase errors caused by FM recorder/playback head misalignment are automatically measured and used to correct the data. Data compression methods are described and compared. The system hardware is described. Applications using the data base are introduced, including software for power spectral density, instantaneous time history, amplitude histogram, fatigue analysis, and rotordynamics expert system analysis.

High density tape/head interface study

NASA Technical Reports Server (NTRS)

Csengery, L. C.

1983-01-01

The high energy (H sub c approximately or = to 650 oersteds) tapes and high track density (84 tracks per inch) heads investigated had, as its goal, the definition of optimum combinations of head and tape, including the control required of their interfacial dynamics that would enable the manufacture of high rate (150 Mbps) digital tape recorders for unattended space flight.

Space Station Environmental Control and Life Support System Purge Control Pump Assembly Modeling and Analysis

NASA Technical Reports Server (NTRS)

Schunk, R. Gregory; Hunt, Patrick L. (Technical Monitor)

2001-01-01

Preliminary results from a thermal/flow analysis of the Purge Control Pump Assembly (PCPA) indicate that pump performance (mass flow rate) is enhanced via cooling of the housing and lowering of the inlet vapor quality. Under a nominal operational profile (25% duty cycle or less), at the maximum motor dissipation, it appears that the peristaltic tubing temperature will still remain significantly below the expected UPA condenser temperature (78 F max versus approximately 105 F in the condenser) permitting condensation in the pump head.

Flow induced vibrations in the SSME injector heads

NASA Technical Reports Server (NTRS)

Lepore, Frank A.

1991-01-01

A description is given of the flowfield in the Space Shuttle Main Engine (SSME) powerhead, the mechanisms which control flow-induced vibrations, and previous experimental work. An in-depth description is given of the development phase of the program , which includes the analysis, design, and fabrication of liquid oxygen (LOX) posts models used in the experimental phase, as well as test facilities, equipment, and procedures used. Also covered is the experimental data analysis, which includes overall steady state powerhead flowfield as well as the high frequency response of the LOX posts.

Expedition 40 crew in Node 2 after German - U.S. soccer game

NASA Image and Video Library

2014-06-26

ISS040-E-020368 (26 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, shaves the head of NASA astronaut Steve Swanson, commander, in the Unity node of the International Space Station. Gerst used hair clippers fashioned with a vacuum device to garner freshly cut hair. A friendly World Cup Soccer-related agreement between the crew members representing the USA, and Gerst, a German citizen who represents the European Space Agency, called for the American losers of a German-USA match to have their heads shaved. The German team won the match 1-0.

Expedition 40 crew in Node 2 after German - U.S. soccer game

NASA Image and Video Library

2014-06-26

ISS040-E-020364 (26 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, shaves the head of NASA astronaut Steve Swanson, commander, in the Unity node of the International Space Station. Gerst used hair clippers fashioned with a vacuum device to garner freshly cut hair. A friendly World Cup Soccer-related agreement between the crew members representing the USA, and Gerst, a German citizen who represents the European Space Agency, called for the American losers of a German-USA match to have their heads shaved. The German team won the match 1-0.

Expedition 40 crew in Node 2 after German - U.S. soccer game

NASA Image and Video Library

2014-06-26

ISS040-E-020378 (26 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, shaves the head of NASA astronaut Reid Wiseman, flight engineer, in the Unity node of the International Space Station. Gerst used hair clippers fashioned with a vacuum device to garner freshly cut hair. A friendly World Cup Soccer-related agreement between the crew members representing the USA, and Gerst, a German citizen who represents the European Space Agency, called for the American losers of a German-USA match to have their heads shaved. The German team won the match 1-0.

Expedition 40 crew in Node 2 after German - U.S. soccer game

NASA Image and Video Library

2014-06-26

ISS040-E-020383 (26 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, shaves the head of NASA astronaut Reid Wiseman, flight engineer, in the Unity node of the International Space Station. Gerst used hair clippers fashioned with a vacuum device to garner freshly cut hair. A friendly World Cup Soccer-related agreement between the crew members representing the USA, and Gerst, a German citizen who represents the European Space Agency, called for the American losers of a German-USA match to have their heads shaved. The German team won the match 1-0.

Expedition 40 crew in Node 2 after German - U.S. soccer game

NASA Image and Video Library

2014-06-26

ISS040-E-020384 (26 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, shaves the head of NASA astronaut Reid Wiseman, flight engineer, in the Unity node of the International Space Station. Gerst used hair clippers fashioned with a vacuum device to garner freshly cut hair. A friendly World Cup Soccer-related agreement between the crew members representing the USA, and Gerst, a German citizen who represents the European Space Agency, called for the American losers of a German-USA match to have their heads shaved. The German team won the match 1-0.

Visual perception of axes of head rotation

PubMed Central

Arnoldussen, D. M.; Goossens, J.; van den Berg, A. V.

2013-01-01

Registration of ego-motion is important to accurately navigate through space. Movements of the head and eye relative to space are registered through the vestibular system and optical flow, respectively. Here, we address three questions concerning the visual registration of self-rotation. (1) Eye-in-head movements provide a link between the motion signals received by sensors in the moving eye and sensors in the moving head. How are these signals combined into an ego-rotation percept? We combined optic flow of simulated forward and rotational motion of the eye with different levels of eye-in-head rotation for a stationary head. We dissociated simulated gaze rotation and head rotation by different levels of eye-in-head pursuit. We found that perceived rotation matches simulated head- not gaze-rotation. This rejects a model for perceived self-rotation that relies on the rotation of the gaze line. Rather, eye-in-head signals serve to transform the optic flow's rotation information, that specifies rotation of the scene relative to the eye, into a rotation relative to the head. This suggests that transformed visual self-rotation signals may combine with vestibular signals. (2) Do transformed visual self-rotation signals reflect the arrangement of the semi-circular canals (SCC)? Previously, we found sub-regions within MST and V6+ that respond to the speed of the simulated head rotation. Here, we re-analyzed those Blood oxygenated level-dependent (BOLD) signals for the presence of a spatial dissociation related to the axes of visually simulated head rotation, such as have been found in sub-cortical regions of various animals. Contrary, we found a rather uniform BOLD response to simulated rotation along the three SCC axes. (3) We investigated if subject's sensitivity to the direction of the head rotation axis shows SCC axes specifcity. We found that sensitivity to head rotation is rather uniformly distributed, suggesting that in human cortex, visuo-vestibular integration is not arranged into the SCC frame. PMID:23919087

A review of adaptive change in musculoskeletal impedance during space flight and associated implications for postflight head movement control

NASA Technical Reports Server (NTRS)

McDonald, P. V.; Bloomberg, J. J.; Layne, C. S.

1997-01-01

We present a review of converging sources of evidence which suggest that the differences between loading histories experienced in 1-g and weightlessness are sufficient to stimulate adaptation in mechanical impedance of the musculoskeletal system. As a consequence of this adaptive change we argue that we should observe changes in the ability to attenuate force transmission through the musculoskeletal system both during and after space flight. By focusing attention on the relation between human sensorimotor activity and support surfaces, the importance of controlling mechanical energy flow through the musculoskeletal system is demonstrated. The implications of such control are discussed in light of visual-vestibular function in the specific context of head and gaze control during postflight locomotion. Evidence from locomotory biomechanics, visual-vestibular function, ergonomic evaluations of human vibration, and specific investigations of locomotion and head and gaze control after space flight, is considered.

Quantitative 3D analysis of bone in hip osteoarthritis using clinical computed tomography.

PubMed

Turmezei, Tom D; Treece, Graham M; Gee, Andrew H; Fotiadou, Anastasia F; Poole, Kenneth E S

2016-07-01

To assess the relationship between proximal femoral cortical bone thickness and radiological hip osteoarthritis using quantitative 3D analysis of clinical computed tomography (CT) data. Image analysis was performed on clinical CT imaging data from 203 female volunteers with a technique called cortical bone mapping (CBM). Colour thickness maps were created for each proximal femur. Statistical parametric mapping was performed to identify statistically significant differences in cortical bone thickness that corresponded with the severity of radiological hip osteoarthritis. Kellgren and Lawrence (K&L) grade, minimum joint space width (JSW) and a novel CT-based osteophyte score were also blindly assessed from the CT data. For each increase in K&L grade, cortical thickness increased by up to 25 % in distinct areas of the superolateral femoral head-neck junction and superior subchondral bone plate. For increasing severity of CT osteophytes, the increase in cortical thickness was more circumferential, involving a wider portion of the head-neck junction, with up to a 7 % increase in cortical thickness per increment in score. Results were not significant for minimum JSW. These findings indicate that quantitative 3D analysis of the proximal femur can identify changes in cortical bone thickness relevant to structural hip osteoarthritis. • CT is being increasingly used to assess bony involvement in osteoarthritis • CBM provides accurate and reliable quantitative analysis of cortical bone thickness • Cortical bone is thicker at the superior femoral head-neck with worse osteoarthritis • Regions of increased thickness co-locate with impingement and osteophyte formation • Quantitative 3D bone analysis could enable clinical disease prediction and therapy development.

Man in Space, Space in the Seventies.

ERIC Educational Resources Information Center

Froehlich, Walter

Included is a summary of the Apollo lunar program to date. Projected future NASA programs planned for the 1970's are discussed under the headings Skylab, Space Shuttle, and Space Station. Possibilities for the 1980's are outlined in the final section. (Author/AL)

Displays. [three dimensional analog visual system for aiding pilot space perception

NASA Technical Reports Server (NTRS)

1974-01-01

An experimental investigation made to determine the depth cue of a head movement perspective and image intensity as a function of depth is summarized. The experiment was based on the use of a hybrid computer generated contact analog visual display in which various perceptual depth cues are included on a two dimensional CRT screen. The system's purpose was to impart information, in an integrated and visually compelling fashion, about the vehicle's position and orientation in space. Results show head movement gives a 40% improvement in depth discrimination when the display is between 40 and 100 cm from the subject; intensity variation resulted in as much improvement as head movement.

Space: The New Frontier.

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Washington, DC.

This document is designed primarily to describe the U.S. Space Program, its history, its current state of development, and its goals for the future. Chapter headings include: Space and You; The Early History of Space Flight; The Solar System; Space Probes and Satellites; Scientific Satellites and Sounding Rockets; Application Satellites, Unmanned…

Biomechanical analysis of protective countermeasures in underride motor vehicle accidents - biomed 2009.

PubMed

Kumar, Sri; Enz, Bruce; Ponder, Perry L; Anderson, Bob

2009-01-01

Traffic safety has been significantly improved over the past several decades reducing injury and fatality rates. However, there is a paucity of research effort to address the safety issues in underride accidents, specifically the side underride crashes. It is well known that the compromise of occupant space in the vehicle leads to a higher probability of serious or fatal injuries. A better understanding of occupant protection and mechanism of injuries involved in side underride accidents assists in the advancement of safety measures. The present work evaluates the injury potential to occupants during side underride crashes using the car-to-trailer crash methodology. Four crash tests were conducted into the side of a stationary trailer fitted with the side underride guard system (SURG). The SURG used in these tests is 25% lighter than the previous design. A 5th percentile hybrid III female dummy was placed in the driver seat and restrained with the three-point lap and shoulder harness. The anthropometric dummy was instrumented with a head triaxial accelerometer, a chest triaxal accelerometer, a load cell to measure neck force and moment, and a load cell to measure the femur force. The vehicle acceleration was measured using a traxial accelerometer in the rear center tunnel. High speed, standard video and still photos were taken. In all tests, the intrusion was limited to the front structure of the vehicle without any significant compromise to the occupant space. Results indicate that the resultant head and chest accelerations, head injury criterion (HIC), neck force and moment, and femur force were well below the injury tolerance. The present findings support the hypothesis that the SURG not only limits or eliminates the intrusion into the occupant space but also results in biomechanical injury values well below the tolerance limit in motor vehicle crashes.

Characterizing Head Motion in 3 Planes during Combined Visual and Base of Support Disturbances in Healthy and Visually Sensitive Subjects

PubMed Central

Keshner, E.A.; Dhaher, Y.

2008-01-01

Multiplanar environmental motion could generate head instability, particularly if the visual surround moves in planes orthogonal to a physical disturbance. We combined sagittal plane surface translations with visual field disturbances in 12 healthy (29–31 years) and 3 visually sensitive (27–57 years) adults. Center of pressure (COP), peak head angles, and RMS values of head motion were calculated and a 3-dimensional model of joint motion11 was developed to examine gross head motion in 3 planes. We found that subjects standing quietly in front of a visual scene translating in the sagittal plane produced significantly greater (p<0.003) head motion in yaw than when on a translating platform. However, when the platform was translated in the dark or with a visual scene rotating in roll, head motion orthogonal to the plane of platform motion significantly increased (p<0.02). Visually sensitive subjects having no history of vestibular disorder produced large, delayed compensatory head motion. Orthogonal head motions were significantly greater in visually sensitive than in healthy subjects in the dark (p<0.05) and with a stationary scene (p<0.01). We concluded that motion of the visual field can modify compensatory response kinematics of a freely moving head in planes orthogonal to the direction of a physical perturbation. These results suggest that the mechanisms controlling head orientation in space are distinct from those that control trunk orientation in space. These behaviors would have been missed if only COP data were considered. Data suggest that rehabilitation training can be enhanced by combining visual and mechanical perturbation paradigms. PMID:18162402

M.I.T./Canadian vestibular experiments on the Spacelab-1 mission: 4. Space motion sickness: symptoms, stimuli, and predictability

NASA Technical Reports Server (NTRS)

Oman, C. M.; Lichtenberg, B. K.; Money, K. E.; McCoy, R. K.

1986-01-01

Space sickness symptoms were observed by 4 specially trained observers on Spacelab-1. Three reported persistent symptoms, and vomited repeatedly during the first and/or second day of flight. Head movements on all axes were provocative, particularly in pitch and roll. Head acceleration data recorded from 2 symptomatic crewmen showed that after several hours of physical activity in orbit, symptoms appeared, and thereafter both crewmen were compelled to limit head movements. Firm body contact with motionless surfaces helped alleviate symptoms. When crewmembers floated into unfamiliar body orientations in the cabin, inherent ambiguities in static visual orientation cues sometimes produced spatial reorientation episodes which were also provocative. Symptoms largely resembled those of other forms of prolonged motion sickness, superimposed upon other symptoms attributable to fluid shift. All 4 eventually used anti-motion sickness drugs. When they did, vomiting frequency was reduced. By the 4th day, symptoms subsided, and head accelerations again increased in magnitude and variability. Sickness intensity in orbit was not predicted by statistically concordant results of 6 acute preflight susceptibility tests. However, results from a longer duration preflight prism goggles test showed an apparent correlation. All subjects were asymptomatic making head movements in parabolic flight 4 days after the mission, but not 1 year later. Overall, results support the view that space sickness is a motion sickness.

Adaptation to Space: An Introduction

NASA Technical Reports Server (NTRS)

Hargens, Alan R.

1995-01-01

The cardiovascular and musculoskeletal systems are normally exposed to gradients of blood pressure and weight on Earth. These gradients increase blood pressure and tissue weight in dependent tissues of the body. Exposure to actual and simulated microgravity causes blood and tissue fluid to shift from the legs to the head. Studies of humans in space have documented facial edema, space motion sickness, decreased plasma volume, muscle atrophy, and loss of bone strength. Return of astronauts to Earth is accompanied by orthostatic intolerance, decreased neuromuscular coordination, and reduced exercise capacity. These factors decrease performance during descent from orbit and increase risk during emergency egress from the spacecraft. Models of simulated microgravity include 6 deg head-down tilt, immersion, and prolonged horizontal bedrest. Head-down tilt is the most accepted model and studies using this model of up to one year have been performed in Russia. Animal models which offer clear insights into the role of gravity on vertebrates include the developing giraffe and snakes from various habitats. Finally, possible countermeasures to speed readaptation of astronauts to gravity after prolonged space flight will be discussed.

Expanded Polystyrene Re-Expansion Analysis Following Impact Compression

DTIC Science & Technology

2015-03-04

on the higher density (0.08 g/cm3) EAL used in the Sound Protective Helmet No. 4 ( SPH -4) showed a linear relationship between initial EPS...temperature on the cushioning properties of some foamed plastic materials. Packaging Technology Science. 16: 69-76. Palmer, R.P. 1991. SPH -4 aircrew...Slobodnik, B.A. 1979. SPH -4 helmet damage and head injury correlation. Aviation, Space, and Environmental Medicine. 50: 139-146. Slobodnik, B.A

An anatomic and morphometric study of C2 nerve root ganglion and its corresponding foramen.

PubMed

Bilge, Okan

2004-03-01

Exposing and measuring the dorsal root ganglion of the second cervical spinal nerve (C2 ganglion) and the second intervertebral space, which is present between posterior arch of atlas (APA) and lamina of axis (LA). This study aims to investigate the shape, size, and relation of the C2 ganglion with the adjacent structures that limits the corresponding intervertebral space and the alterations of relation between C2 ganglion and APA and between C2 ganglion and LA with the movements of the head bilaterally. In previous studies, the position and the heights of the C2 ganglion have been described. But the shape of the C2 ganglion and its relation to APA and LA by the movement of the head had not been considered previously. Upper cervical spines of 20 cadavers were dissected posteriorly. The muscles attaching to the atlas and axis were resected to ease the head movements. The heights of the C2 ganglion and space were measured in anatomic position and in hyperextension with opposite rotation position of the head. Originally in this study, plastic dough casts were used to obtain reliable outcomes. The shape of the ganglions was defined in three types: 70% were oval, 20% were spindle-like, and 10% were spherical. The height of the C2 ganglion was 4.97 +/- 0.92 mm on the right side and 4.6 +/- 0.84 mm on the left side. The height of the intervertebral space in anatomic position and in hyperextension with rotation to the opposite position of the head were, respectively, 9.74 +/- 1.77 mm and 7.48 +/- 1.44 mm on the right side and 9.64 +/- 1.47 mm and 7.12 +/- 0.96 mm on the left side. There was no bone contact or impact to the ganglion in each position of the head. The C2 ganglions are confident in their place between APA and LA. No bone contact to the C2 ganglion was detected in either normal limited or in forced head motions.

The extracranial arterial system in the heads of beaked whales, with implications on diving physiology and pathogenesis.

PubMed

Costidis, Alexander M; Rommel, Sentiel A

2016-01-01

Beaked whales are medium-sized toothed whales that inhabit depths beyond the continental shelf; thus beaked whale strandings are relatively infrequent compared to those of other cetaceans. Beaked whales have been catapulted into the spotlight by their tendency to strand in association with naval sonar deployment. Studies have shown the presence of gas and fat emboli within the tissues and analysis of gas emboli is suggestive of nitrogen as the primary component. These findings are consistent with human decompression sickness (DCS) previously not thought possible in cetaceans. Because, tissue loading with nitrogen gas is paramount for the manifestation of DCS and nitrogen loading depends largely on the vascular perfusion of the tissues, we examined the anatomy of the extracranial arterial system using stranded carcasses of 16 beaked whales from five different species. Anatomic regions containing lipid and/or air spaces were prioritized as potential locations of nitrogen gas absorption due to the known solubility of nitrogen in adipose tissue and the nitrogen content of air, respectively. Attention was focused on the acoustic fat bodies and accessory sinus system on the ventral head. We found much of the arterial system of the head to contain arteries homologous to those found in domestic mammals. Robust arterial associations with lipid depots and air spaces occurred within the acoustic fat bodies of the lower jaw and pterygoid air sacs of the ventral head, respectively. Both regions contained extensive trabecular geometry with small arteries investing the trabeculae. Our findings suggest the presence of considerable surface area between the arterial system, and the intramandibular fat bodies and pterygoid air sacs. Our observations may provide support for the hypothesis that these structures play an important role in the exchange of nitrogen gas during diving. © 2015 Wiley Periodicals, Inc.

Effects of Long Duration Spaceflight on Venous and Arterial Compliance

NASA Technical Reports Server (NTRS)

Ribeiro, L. C.; Lee, S. M. C.; Martin, D. S.; Ploutz-Snyder, R.; Stenger, M. B.; Westby, C. M.; Platts, S. H.

2014-01-01

The visual impairment and intracranial pressure syndrome (VIIP) is a newly described space flight-associated medical condition made up of a constellation of symptoms affecting at least 34% of American astronauts who have flown International Space Station (ISS) missions. VIIP is defined primarily by visual acuity deficits and anatomical changes to eye structures, and is thought to be related to elevated intracranial pressure secondary to space flightinduced cephalad fluid shifts. Loss of visual acuity could be a significant threat to crew health and performance and may be suggestive of other adaptations with implications for years post-flight. Our primary objective is to determine whether vascular compliance is altered by space flight and whether such adaptations are related to the incidence of VIIP. In particular, we will measure ocular parameters and vascular compliance in vessels of the head and neck in astronauts who have no space flight experience, in astronauts before, during, and after space flight, and in bed rest subjects with conditions similar to space flight. Additionally, we will analyze astronaut data from the Lifetime Surveillance of Astronaut Health (LSAH) archive to determine which factors might be predictive of the development of VIIP. The project will be conducted in four separate but related parts. To understand the baseline condition of astronauts without any prior space flight experience, we will study 10 astronauts who have never flown in space by performing a comprehensive evaluation of the vasculature of the head, neck and eyes. Hemodynamic data (stroke volume and blood pressure), ocular (tonometry and ocular ultrasound), venous and arterial parameters will be acquired across a range of tilt angles (20, 10, 0, -10, -20 degrees). Vessels to be studied include the temporal, jugular, and vertebral veins and the cerebral, carotid and vertebral arteries. Ophthalmic data from the annual physical will be obtained through data sharing. To examine the relation between vascular compliance in the head and neck and the development of VIIP after a long duration space flight, we will study 10 astronauts before, during, and after long-duration ISS missions. Pre- and post-flight testing will be identical to that described above. During flight, images of the same vessels of interest will be obtained for later analysis. Ophthalmic data including VIIP scores will be obtained through data sharing from medically-required tests. To investigate the effects of age and elevated sodium intake, two potential contributors to VIIP, we will study 24 men (in two age groups: 25-35 and 45-55) during a 14 day 6deg head-down bed rest, a well-accepted analog of space flight. Standard NASA bed rest conditions will be maintained except for dietary sodium. Sodium intake will be similar to that of ISS astronauts, which is higher than consumed in previous bed rest studies. Pre- and post-bed rest testing procedures will be identical to the testing protocol described above for astronauts. Ophthalmic testing (optical coherence tomography, fundoscopy, and tonometry) will be conducted on the same day that vascular compliance measures are obtained. To identify parameters that may relate to an increase in an astronaut's susceptibility to developing VIIP, we will use data mining techniques to evaluate astronaut data obtained from the LSAH. Medical history, family history, space flight history and its related exposures, and history of high performance jet aircraft exposure will be examined for their potential relationship to ocular data. We hypothesize that the cephalad fluid shift induced by space flight will result in structural and functional adaptations in head and neck vessels leading to decreased vascular compliance and related to the development of VIIP symptoms. Further, although VIIP has not been observed in previous bed rest studies, we hypothesize that an elevated sodium intake will increase the incidence of VIIP symptoms in this space flight analog. Finally, we hypothesize that data mining analyses will reveal relationships between health history, previous exposures (including space flight and high performance aircraft), and the development of VIIP in the astronaut population.

Finite Element Modeling Techniques for Analysis of VIIP

NASA Technical Reports Server (NTRS)

Feola, Andrew J.; Raykin, J.; Gleason, R.; Mulugeta, Lealem; Myers, Jerry G.; Nelson, Emily S.; Samuels, Brian C.; Ethier, C. Ross

2015-01-01

Visual Impairment and Intracranial Pressure (VIIP) syndrome is a major health concern for long-duration space missions. Currently, it is thought that a cephalad fluid shift in microgravity causes elevated intracranial pressure (ICP) that is transmitted along the optic nerve sheath (ONS). We hypothesize that this in turn leads to alteration and remodeling of connective tissue in the posterior eye which impacts vision. Finite element (FE) analysis is a powerful tool for examining the effects of mechanical loads in complex geometries. Our goal is to build a FE analysis framework to understand the response of the lamina cribrosa and optic nerve head to elevations in ICP in VIIP.

LOX/LH2 vane pump for auxiliary propulsion systems

NASA Technical Reports Server (NTRS)

Hemminger, J. A.; Ulbricht, T. E.

1985-01-01

Positive displacement pumps offer potential efficiency advantages over centrifugal pumps for future low thrust space missions. Low flow rate applications, such as space station auxiliary propulsion or dedicated low thrust orbiter transfer vehicles, are typical of missions where low flow and high head rise challenge centrifugal pumps. The positive displacement vane pump for pumping of LOX and LH2 is investigated. This effort has included: (1) a testing program in which pump performance was investigated for differing pump clearances and for differing pump materials while pumping LN2, LOX, and LH2; and (2) an analysis effort, in which a comprehensive pump performance analysis computer code was developed and exercised. An overview of the theoretical framework of the performance analysis computer code is presented, along with a summary of analysis results. Experimental results are presented for pump operating in liquid nitrogen. Included are data on the effects on pump performance of pump clearance, speed, and pressure rise. Pump suction performance is also presented.

Reinterpreting the Authority of Heads: Making Space for Values-Led School Improvement with the "Index for Inclusion"

ERIC Educational Resources Information Center

Higham, Rupert; Booth, Tony

2018-01-01

To what extent can heads use an inclusive values-led approach to school development in the face of pressures from Ofsted and their Local Authority to focus almost exclusively on attainment outcomes? We explore leadership of school improvement in a qualitative study of 10 head teachers in the English county of "Preshire," who worked with…

Head Up Displays. (Latest Citations from the Aerospace Database)

NASA Technical Reports Server (NTRS)

1997-01-01

The bibliography contains citations concerning the design, fabrication, and applications of head up displays (HUDs). Applications include military aircraft, helicopters, space shuttle, and commercial aircraft. Functions of the display include instrument approach, target tracking, and navigation. The head up display provides for an integrated avionics system with the pilot in the loop. (Contains 50-250 citations and includes a subject term index and title list.)

Head Up Displays. (Latest citations from the Aerospace Database)

NASA Technical Reports Server (NTRS)

1996-01-01

The bibliography contains citations concerning the design, fabrication, and applications of head up displays (HUDs). Applications include military aircraft, helicopters, space shuttle, and commercial aircraft. Functions of the display include instrument approach, target tracking, and navigation. The head up display provides for an integrated avionics system with the pilot in the loop. (Contains 50-250 citations and includes a subject term index and title list.)

Pulsed jet combustion generator for non-premixed charge engines

DOEpatents

Oppenheim, A. K.; Stewart, H. E.

1990-01-01

A device for introducing fuel into the head space of cylinder of non-premixed charge (diesel) engines is disclosed, which distributes fuel in atomized form in a plume, whose fluid dynamic properties are such that the compression heated air in the cylinder head space is entrained into the interior of the plume where it is mixed with and ignites the fuel in the plume interior, to thereby control combustion, particularly by use of a multiplicity of individually controllable devices per cylinder.

40. Detail of fireplace ornament, nearly life size heads of ...

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

40. Detail of fireplace ornament, nearly life size heads of General Stilwell and associated personnel, evenly spaced across the entire face of the mantlepiece. - Fort Ord, Soldiers' Club, California State Highway 1 near Eighth Street, Seaside, Monterey County, CA

Visual-Motor Transformations Within Frontal Eye Fields During Head-Unrestrained Gaze Shifts in the Monkey.

PubMed

Sajad, Amirsaman; Sadeh, Morteza; Keith, Gerald P; Yan, Xiaogang; Wang, Hongying; Crawford, John Douglas

2015-10-01

A fundamental question in sensorimotor control concerns the transformation of spatial signals from the retina into eye and head motor commands required for accurate gaze shifts. Here, we investigated these transformations by identifying the spatial codes embedded in visually evoked and movement-related responses in the frontal eye fields (FEFs) during head-unrestrained gaze shifts. Monkeys made delayed gaze shifts to the remembered location of briefly presented visual stimuli, with delay serving to dissociate visual and movement responses. A statistical analysis of nonparametric model fits to response field data from 57 neurons (38 with visual and 49 with movement activities) eliminated most effector-specific, head-fixed, and space-fixed models, but confirmed the dominance of eye-centered codes observed in head-restrained studies. More importantly, the visual response encoded target location, whereas the movement response mainly encoded the final position of the imminent gaze shift (including gaze errors). This spatiotemporal distinction between target and gaze coding was present not only at the population level, but even at the single-cell level. We propose that an imperfect visual-motor transformation occurs during the brief memory interval between perception and action, and further transformations from the FEF's eye-centered gaze motor code to effector-specific codes in motor frames occur downstream in the subcortical areas. © The Author 2014. Published by Oxford University Press.

A model of head-related transfer functions based on a state-space analysis

NASA Astrophysics Data System (ADS)

Adams, Norman Herkamp

This dissertation develops and validates a novel state-space method for binaural auditory display. Binaural displays seek to immerse a listener in a 3D virtual auditory scene with a pair of headphones. The challenge for any binaural display is to compute the two signals to supply to the headphones. The present work considers a general framework capable of synthesizing a wide variety of auditory scenes. The framework models collections of head-related transfer functions (HRTFs) simultaneously. This framework improves the flexibility of contemporary displays, but it also compounds the steep computational cost of the display. The cost is reduced dramatically by formulating the collection of HRTFs in the state-space and employing order-reduction techniques to design efficient approximants. Order-reduction techniques based on the Hankel-operator are found to yield accurate low-cost approximants. However, the inter-aural time difference (ITD) of the HRTFs degrades the time-domain response of the approximants. Fortunately, this problem can be circumvented by employing a state-space architecture that allows the ITD to be modeled outside of the state-space. Accordingly, three state-space architectures are considered. Overall, a multiple-input, single-output (MISO) architecture yields the best compromise between performance and flexibility. The state-space approximants are evaluated both empirically and psychoacoustically. An array of truncated FIR filters is used as a pragmatic reference system for comparison. For a fixed cost bound, the state-space systems yield lower approximation error than FIR arrays for D>10, where D is the number of directions in the HRTF collection. A series of headphone listening tests are also performed to validate the state-space approach, and to estimate the minimum order N of indiscriminable approximants. For D = 50, the state-space systems yield order thresholds less than half those of the FIR arrays. Depending upon the stimulus uncertainty, a minimum state-space order of 7≤N≤23 appears to be adequate. In conclusion, the proposed state-space method enables a more flexible and immersive binaural display with low computational cost.

Around Marshall

NASA Image and Video Library

1993-12-15

Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. Marshall Spce Flight Center (MSFC) is begirning to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models are used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup is to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability provides general visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC).

Locomotor Dysfunction after Long-duration Space Flight and Development of Countermeasures to Facilitate Faster Recovery

NASA Astrophysics Data System (ADS)

Mulavara, Ajitkumar; Wood, Scott; Cohen, Helen; Bloomberg, Jacob

2012-07-01

Exposure to the microgravity conditions of space flight induces adaptive modification in sensorimotor function allowing astronauts to operate in this unique environment. This adaptive state, however, is inappropriate for a 1-g environment. Consequently astronauts must spend time readapting to Earth's gravity following their return to Earth. During this readaptation period, alterations in sensorimotor function cause various disturbances in astronaut gait during postflight walking. They often rely more on vision for postural and gait stability and many report the need for greater cognitive supervision of motor actions that previous to space flight were fully automated. Over the last several years our laboratory has investigated postflight astronaut locomotion with the aim of better understanding how adaptive changes in underlying sensorimotor mechanisms contribute to postflight gait dysfunction. Exposure to the microgravity conditions of space flight induces adaptive modification in the control of vestibularly-mediated reflexive head movement during locomotion after space flight. Furthermore, during motor learning, adaptive transitions are composed of two main mechanisms: strategic and plastic. Strategic mechanisms represent immediate and transitory modifications in control to deal with changes in the prevailing environment that, if prolonged, induce plastic mechanisms designed to automate new behavioral responses. The goal of the present study was to examine the contributions of sensorimotor subsystems such as the vestibular and body load sensing (BLS) somatosensory influences on head movement control during locomotion after long-duration space flight. Further we present data on the two motor learning processes during readaptation of locomotor function after long-duration space flight. Eighteen astronauts performed two tests of locomotion before and after 6 months of space flight: a treadmill walking test to examine vestibular reflexive mechanisms controlling head movement control and a functional mobility test to investigate overall functional locomotor ability. Postflight sessions were given on days 1, 2, 4, 7 after their return. Subjects walked on a treadmill driven at 1.8 m/s while performing a visual task. Motion data from head and trunk segmental motion data were obtained to calculate the angular head pitch (HP) movements during walking trials while subjects performed the visual task, to estimate the contributions of vestibular reflexive mechanisms in HP movements. Astronauts showed a heterogeneous response pattern of both increases and decreases in the amplitude of HP movement. We investigated the underlying mechanisms of this heterogeneity in postflight responses in head movement control by examining data obtained using the same experimental test paradigm on a vestibular clinical population (VC) and in normal subjects undergoing adaptation to acute body load support unloading. Results showed that exposure to unloaded locomotion caused a significant increase in HP movements, whereas in the VC patients the HP movements were significantly decreased. We infer that BLS-mediated somatosensory input centrally modulates vestibular input and can adaptively modify head-movement control during locomotion. Thus, space flight may cause a central adaptation of the converging vestibular and body load-sensing somatosensory systems. To investigate changes in functional mobility astronaut subjects walked at their preferred pace around an obstacle course consisting of several pylons and obstacles set up on a foam floor, which provided an unstable walking surface. Subjects were instructed to walk around the course as fast as possible without touching any of the objects on the course for a total of six individual trials per test session. One of the dependent measures was time to complete the course (TCC, sec). The learning rate over the six trials performed on preflight and the first day after landing (micro curve) was used to characterize the immediate compensatory strategic response. The learning rate over the six trials of the postflight test days (macro curve) was used to characterize the longer-term plastic response. Adaptation to space flight led to a 52% increase in TCC one day after landing. Recovery to pre-flight scores took an average of two weeks after landing. Subjects showed both strategic and plastic recovery patterns based on the slopes obtained from the micro and macro curves compared to preflight. A regression analysis revealed a significant correlation between the slope values of the macro and micro curves indicating a relationship between strategic and plastic recovery processes. Results showed that both strategic and plastic motor learning processes play a role in postflight restoration of functional mobility and showed a dynamic interplay between these two mechanisms during postflight recovery. These results suggest that gait adaptability training programs which are being developed to facilitate adaptive transition to planetary environments, coupled with low levels of electrical stimulation of the vestibular system, can be optimized to engage both strategic and plastic processes to facilitate rapid restoration of postflight functional mobility.

Jet plume injection and combustion system for internal combustion engines

DOEpatents

Oppenheim, A.K.; Maxson, J.A.; Hensinger, D.M.

1993-12-21

An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure. 24 figures.

Jet plume injection and combustion system for internal combustion engines

DOEpatents

Oppenheim, Antoni K.; Maxson, James A.; Hensinger, David M.

1993-01-01

An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure.

Tough budget year ahead, says NASA's Fisk

NASA Astrophysics Data System (ADS)

Cole, Stephen

1992-02-01

Lennard Fisk, head of NASA's space science and applications division, painted a bleak picture for space scientists on February 14 as the Bush administration's fiscal 1993 budget headed to Congress. Speaking at the annual meeting of the Space Science Working Group in Washington, D.C., Fisk said “It's going to take a miracle to get the $2,985 billion request” for space science in this year's NASA budget.Fisk held out no hope that programs already cut from the budget, such as the Comet Rendezvous/Asteroid Flyby mission, would be reinstated. The CRAF cancellation was “a $50 million issue in fiscal 1993,” said Fisk, “and it was $50 million that simply wasn't there.” His office “was under enormous pressure to take something off the plate,” he said.

Robot-friendly connector. [space truss structures

NASA Technical Reports Server (NTRS)

Parma, George F. (Inventor); Vandeberghe, Mark H. (Inventor); Ruiz, Steve C. (Inventor)

1993-01-01

Robot friendly connectors, which, in one aspect, are truss joints with two parts, a receptacle and a joint, are presented. The joints have a head which is loosely inserted into the receptacle and is then tightened and aligned. In one aspect, the head is a rounded hammerhead which initially is enclosed in the receptacle with sloppy fit provided by the shape, size, and configuration of surfaces on the head and on the receptacle.

Studies of the vestibulo-ocular reflex on STS 4, 5 and 6

NASA Technical Reports Server (NTRS)

Thornton, William E.; Pool, Sam L.; Moore, Thomas P.; Uri, John J.

1988-01-01

The vestibulo-ocular reflex (VOR) may be altered by weightlessness. Since this reflex plays a large role in visual stabilization, it was important to document any changes caused by space flight. This is a report on findings on STS-4 through 6 and is part of a larger study of neurosensory adaptation done on STS-4 through 8. Voluntary horizontal head oscillations at 1/3 Hz with amplitude of 30 deg right and left of center were recorded by a potentiometer and compared to eye position recorded by electroculography under the following conditions: eyes open, head fixed, tracking horizontal targets switched 0, 15, and 30 degrees right and left (optokinetic reflex - OKR - and calibration); eyes open and fixed on static external target with oscillation, (vestibulo ocular reflex, eyes closed - VOR EC); eyes open and wearing opaque goggles with target fixed in imagination (vestibulo-ocular reflex, eyes shaded - VOR ES); and eyes open and fixed on a head synchronized target with head oscillation (VOR suppression). No significant changes were found in voluntary head oscillation frequency or amplitude in those with (n=5), and without (n=3), space motion sickness (SMS), with phase of flight or test condition. Variations in head oscillation were too small to have produced detectable changes in test results.

High Slew-Rate Head-Only Gradient for Improving Distortion in Echo Planar Imaging: Preliminary Experience

PubMed Central

Tan, Ek T.; Lee, Seung-Kyun; Weavers, Paul T.; Graziani, Dominic; Piel, Joseph E.; Shu, Yunhong; Huston, John; Bernstein, Matt A.; Foo, Thomas K.F.

2016-01-01

Purpose To investigate the effects on echo planar imaging (EPI) distortion of using high gradient slew rates (SR) of up to 700 T/m/s for in-vivo human brain imaging, with a dedicated, head-only gradient coil. Materials and Methods Simulation studies were first performed to determine the expected echo spacing and distortion reduction in EPI. A head gradient of 42-cm inner diameter and with asymmetric transverse coils was then installed in a whole-body, conventional 3T MRI system. Human subject imaging was performed on five subjects to determine the effects of EPI on echo spacing and signal dropout at various gradient slew rates. The feasibility of whole-brain imaging at 1.5 mm-isotropic spatial resolution was demonstrated with gradient-echo and spin-echo diffusion-weighted EPI. Results As compared to a whole-body gradient coil, the EPI echo spacing in the head-only gradient coil was reduced by 48%. Simulation and in vivo results, respectively, showed up to 25-26% and 19% improvement in signal dropout. Whole-brain imaging with EPI at 1.5 mm spatial resolution provided good whole-brain coverage, spatial linearity, and low spatial distortion effects. Conclusion Our results of human brain imaging with EPI using the compact head gradient coil at slew rates higher than in conventional whole-body MR systems demonstrate substantially improved image distortion, and point to a potential for benefits to non-EPI pulse sequences. PMID:26921117

Design of multihundredwatt DIPS for robotic space missions

NASA Technical Reports Server (NTRS)

Bents, D. J.; Geng, S. M.; Schreiber, J. G.; Withrow, C. A.; Schmitz, P. C.; Mccomas, Thomas J.

1991-01-01

Design of a dynamic isotope power system (DIPS) general purpose heat source (GPHS) and small free piston Stirling engine (FPSE) is being pursued as a potential lower cost alternative to radioisotope thermoelectric generators (RTG's). The design is targeted at the power needs of future unmanned deep space and planetary surface exploration missions ranging from scientific probes to SEI precursor missions. These are multihundredwatt missions. The incentive for any dynamic system is that it can save fuel which reduces cost and radiological hazard. However, unlike a conventional DIPS based on turbomachinery converions, the small Stirling DIPS can be advantageously scaled to multihundred watt unit size while preserving size and weight competitiveness with RTG's. Stirling conversion extends the range where dynamic systems are competitive to hundreds of watts (a power range not previously considered for dynamic systems). The challenge of course is to demonstrate reliability similar to RTG experience. Since the competative potential of FPSE as an isotope converter was first identified, work has focused on the feasibility of directly integrating GPHS with the Stirling heater head. Extensive thermal modeling of various radiatively coupled heat source/heater head geometries were performed using data furnished by the developers of FPSE and GPHS. The analysis indicates that, for the 1050 K heater head configurations considered, GPHS fuel clad temperatures remain within safe operating limits under all conditions including shutdown of one engine. Based on these results, preliminary characterizations of multihundred watt units were established.

State-space receptive fields of semicircular canal afferent neurons in the bullfrog

NASA Technical Reports Server (NTRS)

Paulin, M. G.; Hoffman, L. F.

2001-01-01

Receptive fields are commonly used to describe spatial characteristics of sensory neuron responses. They can be extended to characterize temporal or dynamical aspects by mapping neural responses in dynamical state spaces. The state-space receptive field of a neuron is the probability distribution of the dynamical state of the stimulus-generating system conditioned upon the occurrence of a spike. We have computed state-space receptive fields for semicircular canal afferent neurons in the bullfrog (Rana catesbeiana). We recorded spike times during broad-band Gaussian noise rotational velocity stimuli, computed the frequency distribution of head states at spike times, and normalized these to obtain conditional pdfs for the state. These state-space receptive fields quantify what the brain can deduce about the dynamical state of the head when a single spike arrives from the periphery. c2001 Elsevier Science B.V. All rights reserved.

Inertial vestibular coding of motion: concepts and evidence

NASA Technical Reports Server (NTRS)

Hess, B. J.; Angelaki, D. E.

1997-01-01

Central processing of inertial sensory information about head attitude and motion in space is crucial for motor control. Vestibular signals are coded relative to a non-inertial system, the head, that is virtually continuously in motion. Evidence for transformation of vestibular signals from head-fixed sensory coordinates to gravity-centered coordinates have been provided by studies of the vestibulo-ocular reflex. The underlying central processing depends on otolith afferent information that needs to be resolved in terms of head translation related inertial forces and head attitude dependent pull of gravity. Theoretical solutions have been suggested, but experimental evidence is still scarce. It appears, along these lines, that gaze control systems are intimately linked to motor control of head attitude and posture.

Expedition 40 crew in Node 2 after German - U.S. soccer game

NASA Image and Video Library

2014-06-26

ISS040-E-020367 (26 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, shaves the head of NASA astronaut Steve Swanson, commander, in the Unity node of the International Space Station. Gerst used hair clippers fashioned with a vacuum device to garner freshly cut hair. Russian cosmonaut Alexander Skvortsov, flight engineer, is visible in the background. A friendly World Cup Soccer-related agreement between the crew members representing the USA, and Gerst, a German citizen who represents the European Space Agency, called for the American losers of a German-USA match to have their heads shaved. The German team won the match 1-0.

Effects of Mild Hypercapnia During Head-Down Bed Rest on Ocular Structures, Cerebral Blood Flow, aud Visual Acuity in Healthy Human Subjects

NASA Technical Reports Server (NTRS)

Laurie, S. S.; Taibbi, G.; Lee, S. M. C.; Martin, D. S.; Zanello, S.; Ploutz-Snyder, R.; Hu, X.; Stenger, M. B.; Vizzeri, G.

2014-01-01

The cephalad fluid shift induced by microgravity has been hypothesized to cause an elevation in intracranial pressure (ICP) and contribute to the development of the Visual Impairment/Intracranial Pressure (VIIP) syndrome, as experienced by some astronauts during long-duration space flight. Elevated ambient partial pressure of carbon dioxide (PCO2) on ISS may also raise ICP and contribute to VIIP development. We seek to determine if the combination of mild CO2 exposure, similar to that occurring on the International Space Station, with the cephalad fluid shift induced by head-down tilt, will induce ophthalmic and cerebral blood flow changes similar to those described in the VIIP syndrome. We hypothesize that mild hypercapnia in the head-down tilt position will increase choroidal blood volume and cerebral blood flow, raise intraocular pressure (IOP), and transiently reduce visual acuity as compared to the seated or the head-down tilt position without elevated CO2, respectively.

Design and development of a Space Station proximity operations research and development mockup

NASA Technical Reports Server (NTRS)

Haines, Richard F.

1986-01-01

Proximity operations (Prox-Ops) on-orbit refers to all activities taking place within one km of the Space Station. Designing a Prox-Ops control station calls for a comprehensive systems approach which takes into account structural constraints, orbital dynamics including approach/departure flight paths, myriad human factors and other topics. This paper describes a reconfigurable full-scale mock-up of a Prox-Ops station constructed at Ames incorporating an array of windows (with dynamic star field, target vehicle(s), and head-up symbology), head-down perspective display of manned and unmanned vehicles, voice- actuated 'electronic checklist', computer-generated voice system, expert system (to help diagnose subsystem malfunctions), and other displays and controls. The facility is used for demonstrations of selected Prox-Ops approach scenarios, human factors research (work-load assessment, determining external vision envelope requirements, head-down and head-up symbology design, voice synthesis and recognition research, etc.) and development of engineering design guidelines for future module interiors.

Cognitive Functioning in Long Duration Head-down Bed Rest

NASA Technical Reports Server (NTRS)

Seaton, Kimberly A.; Slack, Kelley J.; Sipes, Walter A.; Bowie, Kendra

2008-01-01

The Space Flight Cognitive Assessment Tool for Windows (WinSCAT) is a self-administered battery of tests used on the International Space Station for evaluating cognitive functioning. Here, WinSCAT was used to assess cognitive functioning during extended head-down bed rest. Thirteen subjects who participated in 60 or 90 days of 6 deg head-down bed rest took WinSCAT during the pre-bed rest phase, the in-bed rest phase, and the post-bed rest (reconditioning) phase of study participation. After adjusting for individual baseline performance, 12 off-nominal scores were observed out of 351 total observations during bed rest and 7 of 180 during reconditioning. No evidence was found for systematic changes in off-nominal incidence as time in bed rest progressed, or during the reconditioning period. Cognitive functioning does not appear to be adversely affected by long duration head-down bed rest. Individual differences in underlying cognitive ability and motivation level are likely explanations for the current findings.

Thrust imbalance of the Space Shuttle solid rocket motors

NASA Technical Reports Server (NTRS)

Foster, W. A., Jr.; Sforzini, R. H.; Shackelford, B. W., Jr.

1981-01-01

The Monte Carlo statistical analysis of thrust imbalance is applied to both the Titan IIIC and the Space Shuttle solid rocket motors (SRMs) firing in parallel, and results are compared with those obtained from the Space Shuttle program. The test results are examined in three phases: (1) pairs of SRMs selected from static tests of the four developmental motors (DMs 1 through 4); (2) pairs of SRMs selected from static tests of the three quality assurance motors (QMs 1 through 3); (3) SRMs on the first flight test vehicle (STS-1A and STS-1B). The simplified internal ballistic model utilized for computing thrust from head-end pressure measurements on flight tests is shown to agree closely with measured thrust data. Inaccuracies in thrust imbalance evaluation are explained by possible flight test instrumentation errors.

Space: where are we headed?

PubMed

Jones, Thomas D

2003-04-01

In a new column, the author reviews NASA space activities since the beginning of 2003 and looks at plans for the future. Topics include the Space Shuttle Columbia, what's in store for the International Space Station (ISS), the development of an orbital space plane, orbiter safety upgrades, and the future of space exploration and research beyond the ISS. He presents arguments for sending astronauts to asteroids, the Moon, and Mars.

Effect of crystallographical and geometrical changes of a ferrite head on magnetic signals during the sliding process with magnetic tape

NASA Technical Reports Server (NTRS)

Miyoshi, K.; Buckley, D. H.; Tanaka, K.

1986-01-01

This paper reviews changes in the crystalline structure and geometry of lapped Mn-Zn ferrite heads in sliding contact with magnetic tape and the effects of these changes on magnetic signals. A highly textured, polycrystalline structure was produced on the surface of a single-crystal Mn-Zn ferrite head when it was finished with an aluminum oxide lapping tape. Sliding this lapped surface against a magnetic tape produced a nearly amorphous structure. The sliding process led to a degradation in readback signal of 1 to 2 dB (short-wavelength recording). Furthermore, wear of the magnetic head caused geometrical changes in the head surface. The signal read back with the worn magnetic head was sensitive to operating parameters such as head displacement and tape tension. A change in operating parameters created head-to-tape spacings and, consequently, excessive gains or losses in the readback signal.

Sealed head access area enclosure

DOEpatents

Golden, Martin P.; Govi, Aldo R.

1978-01-01

A liquid-metal-cooled fast breeder power reactor is provided with a sealed head access area enclosure disposed above the reactor vessel head consisting of a plurality of prefabricated structural panels including a center panel removably sealed into position with inflatable seals, and outer panels sealed into position with semipermanent sealant joints. The sealant joints are located in the joint between the edge of the panels and the reactor containment structure and include from bottom to top an inverted U-shaped strip, a lower layer of a room temperature vulcanizing material, a separator strip defining a test space therewithin, and an upper layer of a room temperature vulcanizing material. The test space is tapped by a normally plugged passage extending to the top of the enclosure for testing the seal or introducing a buffer gas thereinto.

Recent bed rest results and countermeasure development at NASA

NASA Technical Reports Server (NTRS)

Hargens, A. R.

1994-01-01

Bedrest studies of normal subjects provide opportunities to understand physiologic responses to supine posture and inactivity. Furthermore, head-down tilt has been a valuable procedure to investigate adaptation to microgravity and development of countermeasures to maintain the health and well-being of humans during space-flight. Recent bedrest experiments at NASA have ranged in duration from a few hours to 17 weeks. Acute studies of 6 degrees head-down tilt indicate that elevation of capillary blood pressure from 28 to 34 mm Hg and increased capillary perfusion in tissues of the head cause facial and intracranial edema. Intracranial pressure increases from 2 to 17 mm Hg going from upright posture to 6 degrees head-down tilt. Microvessels of the head have a low capacity to constrict and diminish local perfusion. Elevation of blood and tissue fluid pressures/flow in the head may also explain the higher headward bone density associated with long-term head-down tilt. These mechanistic studies of head-down tilt, along with a better understanding of the relative stresses involved with upright posture and lower body negative pressure, have facilitated development of suitable physiologic countermeasures to maintain astronaut health during microgravity. Presently no exercise hardware is available to provide a blood pressure gradient from head to feet in space. However, recent studies in our laboratory suggest that treadmill exercise using a graded lower-body compression suit and 100 mmHg lower body negative pressure provides equivalent or greater physiologic stress than similar upright exercise on Earth. Therefore, exercise within a lower body negative pressure chamber may provide a cost-effective and simple countermeasure to maintain the cardiovascular and neuro-musculoskeletal systems of astronauts during long-duration flight.

14 CFR 1201.103 - Administration.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Administration. 1201.103 Section 1201.103 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION STATEMENT OF ORGANIZATION AND GENERAL INFORMATION Introduction § 1201.103 Administration. (a) NASA is headed by an Administrator, who is appointed...

14 CFR 1201.103 - Administration.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Administration. 1201.103 Section 1201.103 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION STATEMENT OF ORGANIZATION AND GENERAL INFORMATION Introduction § 1201.103 Administration. (a) NASA is headed by an Administrator, who is appointed...

14 CFR 1201.103 - Administration.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false Administration. 1201.103 Section 1201.103 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION STATEMENT OF ORGANIZATION AND GENERAL INFORMATION Introduction § 1201.103 Administration. (a) NASA is headed by an Administrator, who is appointed...

14 CFR 1201.103 - Administration.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Administration. 1201.103 Section 1201.103 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION STATEMENT OF ORGANIZATION AND GENERAL INFORMATION Introduction § 1201.103 Administration. (a) NASA is headed by an Administrator, who is appointed...

Effect of Fin Passage Length on Optimization of Cylinder Head Cooling Fins

NASA Technical Reports Server (NTRS)

Siegel, R.; Graham, R. W.

1977-01-01

The heat transfer performance of baffled cooling fins on cylinder heads of small, air-cooled, general-aviation aircraft engines was analyzed to determine the potential for improving cooling fin design. Flow baffles were assumed to be installed tightly against the fin end edges, an ideal baffle configuration for guiding all flow between the fins. A rectangular flow passage is thereby formed between each set of two adjacent fins, the fin base surface, and the baffle. These passages extend around each side of the cylinder head, and the cooling air absorbs heat as it flows within them. For each flow passage length, the analysis was concerned with optimizing fin spacing and thickness to achieve the best heat transfer for each fin width. Previous literature has been concerned mainly with maximizing the local fin conductance and has not considered the heating of the gas in the flow direction, which leads to higher wall temperatures at the fin passage exits. If the fins are close together, there is a large surface area, but the airflow is restricted.

In search of rules behind environmental framing; the case of head pitch.

PubMed

Wilson, Gwendoline Ixia; Norman, Brad; Walker, James; Williams, Hannah J; Holton, M D; Clarke, D; Wilson, Rory P

2015-01-01

Whether, and how, animals move requires them to assess their environment to determine the most appropriate action and trajectory, although the precise way the environment is scanned has been little studied. We hypothesized that head attitude, which effectively frames the environment for the eyes, and the way it changes over time, would be modulated by the environment. To test this, we used a head-mounted device (Human-Interfaced Personal Observation platform - HIPOP) on people moving through three different environments; a botanical garden ('green' space), a reef ('blue' space), and a featureless corridor, to examine if head movement in the vertical axis differed between environments. Template matching was used to identify and quantify distinct behaviours. The data on head pitch from all subjects and environments over time showed essentially continuous clear waveforms with varying amplitude and wavelength. There were three stylised behaviours consisting of smooth, regular peaks and troughs in head pitch angle and variable length fixations during which the head pitch remained constant. These three behaviours accounted for ca. 40 % of the total time, with irregular head pitch changes accounting for the rest. There were differences in rates of manifestation of behaviour according to environment as well as environmentally different head pitch values of peaks, troughs and fixations. Finally, although there was considerable variation in head pitch angles, the peak and trough values bounded most of the variation in the fixation pitch values. It is suggested that the constant waveforms in head pitch serve to inform people about their environment, providing a scanning mechanism. Particular emphasis to certain sectors is manifest within the peak and trough limits and these appear modulated by the distribution of the points where fixation, interpreted as being due to objects of interest, occurs. This behaviour explains how animals allocate processing resources to the environment and shows promise for movement studies attempting to elucidate which parts of the environment affect movement trajectories.

MSVAT-SPACE-STIR and SEMAC-STIR for Reduction of Metallic Artifacts in 3T Head and Neck MRI.

PubMed

Hilgenfeld, T; Prager, M; Schwindling, F S; Nittka, M; Rammelsberg, P; Bendszus, M; Heiland, S; Juerchott, A

2018-05-24

The incidence of metallic dental restorations and implants is increasing, and head and neck MR imaging is becoming challenging regarding artifacts. Our aim was to evaluate whether multiple-slab acquisition with view angle tilting gradient based on a sampling perfection with application-optimized contrasts by using different flip angle evolution (MSVAT-SPACE)-STIR and slice-encoding for metal artifact correction (SEMAC)-STIR are beneficial regarding artifact suppression compared with the SPACE-STIR and TSE-STIR in vitro and in vivo. At 3T, 3D artifacts of 2 dental implants, supporting different single crowns, were evaluated. Image quality was evaluated quantitatively (normalized signal-to-noise ratio) and qualitatively (2 reads by 2 blinded radiologists). Feasibility was tested in vivo in 5 volunteers and 5 patients, respectively. Maximum achievable resolution and the normalized signal-to-noise ratio of MSVAT-SPACE-STIR were higher compared with SEMAC-STIR. Performance in terms of artifact correction was dependent on the material composition. For highly paramagnetic materials, SEMAC-STIR was superior to MSVAT-SPACE-STIR (27.8% smaller artifact volume) and TSE-STIR (93.2% less slice distortion). However, MSVAT-SPACE-STIR reduced the artifact size compared with SPACE-STIR by 71.5%. For low-paramagnetic materials, MSVAT-SPACE-STIR performed as well as SEMAC-STIR. Furthermore, MSVAT-SPACE-STIR decreased artifact volume by 69.5% compared with SPACE-STIR. The image quality of all sequences did not differ systematically. In vivo results were comparable with in vitro results. Regarding susceptibility artifacts and acquisition time, MSVAT-SPACE-STIR might be advantageous over SPACE-STIR for high-resolution and isotropic head and neck imaging. Only for materials with high-susceptibility differences to soft tissue, the use of SEMAC-STIR might be beneficial. Within limited acquisition times, SEMAC-STIR cannot exploit its full advantage over TSE-STIR regarding artifact suppression. © 2018 by American Journal of Neuroradiology.

A Sparsity-Based Approach to 3D Binaural Sound Synthesis Using Time-Frequency Array Processing

NASA Astrophysics Data System (ADS)

Cobos, Maximo; Lopez, JoseJ; Spors, Sascha

2010-12-01

Localization of sounds in physical space plays a very important role in multiple audio-related disciplines, such as music, telecommunications, and audiovisual productions. Binaural recording is the most commonly used method to provide an immersive sound experience by means of headphone reproduction. However, it requires a very specific recording setup using high-fidelity microphones mounted in a dummy head. In this paper, we present a novel processing framework for binaural sound recording and reproduction that avoids the use of dummy heads, which is specially suitable for immersive teleconferencing applications. The method is based on a time-frequency analysis of the spatial properties of the sound picked up by a simple tetrahedral microphone array, assuming source sparseness. The experiments carried out using simulations and a real-time prototype confirm the validity of the proposed approach.

STS-64 launch view

NASA Technical Reports Server (NTRS)

1994-01-01

With a crew of six NASA astronauts aboard, the Space Shuttle Discovery heads for its nineteenth Earth-orbital mission. Launch was delayed because of weather, but all systems were 'go,' and the spacecraft left the launch pad at 6:23 p.m. (EDT) on September 9, 1994. Onboard were astronauts Richard N. Richards, L. Blaine Hammond, Carl J. Meade, Mark C. Lee, Susan J. Helms, and Jerry M. Linenger (051-2); Making a bright reflection in nearby marsh waters, the Space Shuttle Discovery heads for its 19th mission in earth orbit (053).

Water Powered Tools

NASA Technical Reports Server (NTRS)

1976-01-01

Space Spin-Offs, Inc. under a contract with Lewis Research Center and Marshall Space Flight Center produced a new water-powered saw that cuts through concrete and steel plate reducing danger of explosion or electric shock in rescue and other operations. In prototype unit efficient water-powered turbine drives an 8 inch diameter grinding disk at 6,600 rpm. Exhaust water cools disk and workpiece quenching any sparks produced by cutting head. At maximum power, tool easily cuts through quarter inch steel plate. Adapter heads for chain saws, impact wrenches, heavy duty drills, and power hack saws can be fitted.

Cassidy shaving his head

NASA Image and Video Library

2013-05-29

ISS036-E-004795 (29 May 2013) --- NASA astronaut Chris Cassidy, Expedition 36 flight engineer, gives himself a "serious" haircut in the Harmony node onboard the Earth-orbiting International Space Station. Cassidy, who has displayed his sense of humor more than once since coming aboard the orbital outpost in late March, ended up with a completely bald pate when this task was done. The three crew members due to come aboard the station later on this day include one -- Luca Parmitano of the European Space Agency -- who sports a similarly hairless head.

Fundamental Study on the Ozone Posttreatment of Reverse Osmosis Permeates from Army Wastewaters.

DTIC Science & Technology

1981-03-01

organics in RC per- meates as well as for the intermediates formed during ozonation of RO permeate. / This involved the use of distillation, head space...This involved the use of distillation, head - space, and purge and trap methods for the concentration of volatile organic constituents and of the...Grams Group 1 Soap 6.26 INaC 1 7 *C Urea 0.0917 Kaolin 1.725 Talc 1 .7i3 Sho%er Clearer 9.0( Group 2 Hail Oil 14.18 Hai I Gel 3.36 Shampoo 0.456

U.S. Commercial Cargo Craft Heads to the Space Station

NASA Image and Video Library

2018-05-21

The remotely piloted Orbital ATK Cygnus cargo spacecraft launched May 21 from NASA's Wallops Flight Facility, Virginia atop an Antares rocket, headed for a rendezvous with the International Space Station to deliver several tons of scientific experiments and supplies for the station residents. Dubbed the SS “J.R. Thompson” in honor of the late spacefaring manager for both NASA and Orbital ATK, Cygnus will be robotically captured and installed to the earth-facing port of the station’s Unity module for a two-month stay at the orbital outpost.

Blood filling and flow in lungs during change in body position in space

NASA Technical Reports Server (NTRS)

Pogodin, A. S.; Mazhbich, B. I.

1980-01-01

In the horizontal position (supine and lateral), in the upright position (head up and head down) and during change of the cat body position in space, quantitative responses of regional blood volume and blood flow in the lungs (ml/100 cu cm) revealed presence of the gradient in the gravitation direction. Blood volume and blood flow of different lung portions changed qualitatively and quantitatively in different ways. These changes occurred only in the direction producing the equality of regional hydrostatical and hemodynamic loads in the lungs at either horizontal level.

Northrop Grumman HEC flight coaxial cryocoolers performance

NASA Astrophysics Data System (ADS)

Nguyen, T.; Russo, J.; Basel, G.; Chi, D.; Abelson, L.

2018-05-01

The Northrop Grumman Aerospace Systems (NGAS) has expanded the cryocooler product line to include a single stage High Efficiency Cryocooler (HEC) cooler with a coaxial pulse tube cold head that operates at temperatures down to 45K. The HEC coaxial pulse tube cooler has been adopted by several customers, and has completed acceptance testing to meet program flight requirements. The NGAS TRL 9 HEC is a pulse tube cryocooler with a flexure bearing compressor which has been delivered for a number of flight payloads that are currently operating in space. To date, NGAS has delivered space cryocoolers in several configurations including single stage with a linear cold head and two stage with both linear and coaxial cold heads. The new HEC coaxial cooler uses the same TRL9 HEC compressor with a passive pulse tube cold head, to maintain the flight heritage of the HEC linear cooler. In this paper, we present the flight acceptance test data of the HEC coaxial cryocooler, which includes thermal performance, launch vibration and thermal cycling. The HEC coaxial cooler has demonstrated excellent performance in family with the flight qualified HEC linear cooler. The HEC coaxial cooler provides users with additional flexibility in selecting the cold head configuration to meet their particular applications.

External Tank No. 120 heads for the open door of the VAB

NASA Image and Video Library

2007-07-30

Aboard a transporter, external tank No. 120 heads for the open door of the Vehicle Assembly Building. There it will be lifted into a checkout cell. ET-120 will be used for launching Space Shuttle Discovery on mission STS-120 in October.

Global Positioning Svstem (GPS) on International Space Station (ISS) and Crew Return Vehicle (CRV)

NASA Technical Reports Server (NTRS)

Gomez, Susan F.

2002-01-01

Both the International Space Station and Crew Return Vehicle desired to have GPS on their vehicles due to improve state determination over traditional ground tracking techniques used in the past for space vehicles. Both also opted to use GPS for attitude determination to save the expense of a star tracker. Both vehicles have stringent pointing requirements for roll, pitch, and heading, making a sun or earth sensor not a viable option since the heading is undetermined. This paper discusses the technical challenges associated with the implementation of GPS on both of these vehicles. ISS and CRY use the same GPS receiver, but have faced different challenges since the mission of each is di fferent. ISS will be discussed first, then CRY. The flight experiments flown on the Space Shuttle in support of these efforts is also discussed.

KENNEDY SPACE CENTER, FLA. - A KSC employee dons the head and face cover of a "bunny suit," part of standard clean room apparel, before entering a clean room. This apparel is designed to cover the hair, clothing and shoes of employees to prevent particulate matter from contaminating the space flight hardware being stored or processed in the clean room and is one aspect of KSC's Foreign Object Debris (FOD) control program, an important safety initiative.

NASA Image and Video Library

2003-08-29

KENNEDY SPACE CENTER, FLA. - A KSC employee dons the head and face cover of a "bunny suit," part of standard clean room apparel, before entering a clean room. This apparel is designed to cover the hair, clothing and shoes of employees to prevent particulate matter from contaminating the space flight hardware being stored or processed in the clean room and is one aspect of KSC's Foreign Object Debris (FOD) control program, an important safety initiative.

Analysis of volatile components from Melipona beecheii geopropolis from Southeast Mexico by headspace solid-phase microextraction.

PubMed

Torres-González, Ahira; López-Rivera, Paulina; Duarte-Lisci, Georgina; López-Ramírez, Ángel; Correa-Benítez, Adriana; Rivero-Cruz, J Fausto

2016-01-01

A head space solid-phase microextraction method combined with gas chromatography-mass spectrometry was developed and optimised to extract and analyse volatile compounds of Melipona beecheii geopropolis. Seventy-three constituents were identified using this technique in the sample of geopropolis collected. The main compounds detected include β-fenchene (14.53-15.45%), styrene (8.72-9.98%), benzaldehyde (7.44-7.82%) and the most relevant volatile components presents at high level in the geopropolis were terpenoids (58.17%).

Marshall Engineers Use Virtual Reality

NASA Technical Reports Server (NTRS)

1993-01-01

Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. Marshall Spce Flight Center (MSFC) is begirning to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models are used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup is to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability provides general visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC).

Prevalence of subdural collections in children with macrocrania.

PubMed

Greiner, M V; Richards, T J; Care, M M; Leach, J L

2013-12-01

The relationship between enlarged subarachnoid spaces and subdural collections is poorly understood and creates challenges for clinicians investigating the etiology of subdural collections. The purpose of this study was to determine the prevalence of subdural collections on cross sectional imaging in children with macrocephaly correlating with subarachnoid space enlargement. The radiology information system of a large pediatric medical center was reviewed for "macrocrania" and "macrocephaly" on reports of cranial MRI/CT examinations in children <24 months of age, over a 24-month period. Head circumference was obtained from the clinical record. Studies were reviewed blindly for subdural collection presence and subarachnoid space size. Children with prior cranial surgery, parenchymal abnormalities, hydrocephalus, or conditions predisposing to parenchymal volume loss were excluded. Chart review was performed on those with subdural collections. Imaging from 177 children with enlarged head circumference was reviewed. Nine were excluded, for a final cohort of 168 subjects (108 with enlarged subarachnoid space). Subdural collections were identified in 6 (3.6%), all with enlarged subarachnoid space (6/108, 5.6%). In 4, subdural collections were small, homogeneous, and nonhemorrhagic. In 2, the collections were complex (septations or hemorrhage). Two children were reported as victims of child abuse (both with complex collections). No definitive etiology was established in the other cases. The prevalence of subdural collections in imaged children with macrocrania was 3.6%, all occurring in children with enlarged subarachnoid space. Our results suggest that enlarged subarachnoid space can be associated with some subdural collections in this cohort. Despite this, we believe that unexpected subdural collections in children should receive close clinical evaluation for underlying causes, including abusive head trauma.

Exploration Laboratory Analysis FY13

NASA Technical Reports Server (NTRS)

Krihak, Michael; Perusek, Gail P.; Fung, Paul P.; Shaw, Tianna, L.

2013-01-01

The Exploration Laboratory Analysis (ELA) project supports the Exploration Medical Capability (ExMC) risk, which is stated as the Risk of Inability to Adequately Treat an Ill or Injured Crew Member, and ExMC Gap 4.05: Lack of minimally invasive in-flight laboratory capabilities with limited consumables required for diagnosing identified Exploration Medical Conditions. To mitigate this risk, the availability of inflight laboratory analysis instrumentation has been identified as an essential capability in future exploration missions. Mission architecture poses constraints on equipment and procedures that will be available to treat evidence-based medical conditions according to the Space Medicine Exploration Medical Conditions List (SMEMCL), and to perform human research studies on the International Space Station (ISS) that are supported by the Human Health and Countermeasures (HHC) element. Since there are significant similarities in the research and medical operational requirements, ELA hardware development has emerged as a joint effort between ExMC and HHC. In 2012, four significant accomplishments were achieved towards the development of exploration laboratory analysis for medical diagnostics. These achievements included (i) the development of high priority analytes for research and medical operations, (ii) the development of Level 1 functional requirements and concept of operations documentation, (iii) the selection and head-to-head competition of in-flight laboratory analysis instrumentation, and (iv) the phase one completion of the Small Business Innovation Research (SBIR) projects under the topic Smart Phone Driven Blood-Based Diagnostics. To utilize resources efficiently, the associated documentation and advanced technologies were integrated into a single ELA plan that encompasses ExMC and HHC development efforts. The requirements and high priority analytes was used in the selection of the four in-flight laboratory analysis performers. Based upon the competition results, a down select process will be performed in the upcoming year. Looking ahead, this unified effort has positioned each element for an in-flight lab analysis demonstration of select diagnostics measurements in the 2015 timeframe.

Space Cooperation Working Group

NASA Image and Video Library

2010-11-18

NASA Administrator Charles Bolden, left, and NASA Deputy Administrator Lori Garver, welcome Head of the Russian Federal Space Agency Anatoly Perminov, right, for the third Space Cooperation Working Group meeting of the U.S. – Russia Bilateral Presidential Commission on Thursday, Nov. 18, 2010 in Washington. Photo Credit: (NASA/Bill Ingalls)

Evaluation of Operational Procedures for Using a Time-Based Airborne Inter-arrival Spacing Tool

NASA Technical Reports Server (NTRS)

Oseguera-Lohr, Rosa M.; Lohr, Gary W.; Abbott, Terence S.; Eischeid, Todd M.

2002-01-01

An airborne tool has been developed based on the concept of an aircraft maintaining a time-based spacing interval from the preceding aircraft. The Advanced Terminal Area Approach Spacing (ATAAS) tool uses Automatic Dependent Surveillance-Broadcast (ADS-B) aircraft state data to compute a speed command for the ATAAS-equipped aircraft to obtain a required time interval behind another aircraft. The tool and candidate operational procedures were tested in a high-fidelity, full mission simulator with active airline subject pilots flying an arrival scenario using three different modes for speed control. The objectives of this study were to validate the results of a prior Monte Carlo analysis of the ATAAS algorithm and to evaluate the concept from the standpoint of pilot acceptability and workload. Results showed that the aircraft was able to consistently achieve the target spacing interval within one second (the equivalent of approximately 220 ft at a final approach speed of 130 kt) when the ATAAS speed guidance was autothrottle-coupled, and a slightly greater (4-5 seconds), but consistent interval with the pilot-controlled speed modes. The subject pilots generally rated the workload level with the ATAAS procedure as similar to that with standard procedures, and also rated most aspects of the procedure high in terms of acceptability. Although pilots indicated that the head-down time was higher with ATAAS, the acceptability of head-down time was rated high. Oculometer data indicated slight changes in instrument scan patterns, but no significant change in the amount of time spent looking out the window between the ATAAS procedure versus standard procedures.

Previsional space during direct laryngoscopy

PubMed Central

Park, Seongjoo; Han, Ji-Won; Cha, Sukwon; Han, Sung-Hee; Kim, Jin-Hee

2017-01-01

Abstract The laryngoscope should displace oral soft tissues forward out of the operator's vision. Therefore, the space in front of the view may be critical for determining the laryngoscopic view. The aim was to investigate the difference in the previsional space during difficult versus easy laryngoscopy (EL). Under general anesthesia, digital photographs of the lateral view of the head and neck were taken in the horizontal sniffing position, after head extension, and during laryngoscopy with a defined force (50 N). Three points (thyroid notch (T), maxillary incisor (I), and mandibular mentum (M)) were marked on the photograph. The previsional space was defined as the TIM triangle. We compared these areas and other variables of the TIM triangle between male patients with difficult laryngoscopy (DL: Cormack–Lehane III–IV, n = 12) versus those of age- and body mass index-matched male patients with EL (Cormack–Lehane I–II, n = 12). When the head was extended, the areas TIM triangle in DL were significantly smaller than in EL. During laryngoscopy, all values of the TIM triangle in DL, including the TIM area (16.4 ± 3.7 vs 22.6 ± 2.8 cm2, P < .01), were significantly smaller than the values in EL. The previsional space was smaller in patients with DL than in those with EL. The TIM triangle could suggest new way to explain the mechanism underlying DL. PMID:28682897

Previsional space during direct laryngoscopy: Implication in the difficult laryngoscopy.

PubMed

Park, Seongjoo; Han, Ji-Won; Cha, Sukwon; Han, Sung-Hee; Kim, Jin-Hee

2017-07-01

The laryngoscope should displace oral soft tissues forward out of the operator's vision. Therefore, the space in front of the view may be critical for determining the laryngoscopic view. The aim was to investigate the difference in the previsional space during difficult versus easy laryngoscopy (EL).Under general anesthesia, digital photographs of the lateral view of the head and neck were taken in the horizontal sniffing position, after head extension, and during laryngoscopy with a defined force (50 N). Three points (thyroid notch (T), maxillary incisor (I), and mandibular mentum (M)) were marked on the photograph. The previsional space was defined as the TIM triangle. We compared these areas and other variables of the TIM triangle between male patients with difficult laryngoscopy (DL: Cormack-Lehane III-IV, n = 12) versus those of age- and body mass index-matched male patients with EL (Cormack-Lehane I-II, n = 12).When the head was extended, the areas TIM triangle in DL were significantly smaller than in EL. During laryngoscopy, all values of the TIM triangle in DL, including the TIM area (16.4 ± 3.7 vs 22.6 ± 2.8 cm, P < .01), were significantly smaller than the values in EL.The previsional space was smaller in patients with DL than in those with EL. The TIM triangle could suggest new way to explain the mechanism underlying DL.

Graham confirmed as OSTP Head

NASA Astrophysics Data System (ADS)

William R. Graham was confirmed by the Senate on October 1, 1986, as the science advisor to President Ronald Reagan and head of the Office of Science and Technology Policy (OSTP). Formerly the deputy administrator of the National Aeronautics and Space Administration (NASA), Graham started his new post on October 6.

Study of optical design of Blu-ray pickup head system with a liquid crystal element.

PubMed

Fang, Yi-Chin; Yen, Chih-Ta; Hsu, Jui-Hsin

2014-10-10

This paper proposes a newly developed optical design and an active compensation method for a Blu-ray pickup head system with a liquid crystal (LC) element. Different from traditional pickup lens design, this new optical design delivers performance as good as the conventional one but has more room for tolerance control, which plays a role in antishaking devices, such as portable Blu-ray players. A hole-pattern electrode and LC optics with external voltage input were employed to generate a symmetric nonuniform electrical field in the LC layer that directs LC molecules into the appropriate gradient refractive index distribution, resulting in the convergence or divergence of specific light beams. LC optics deliver fast and, most importantly, active compensation through optical design when errors occur. Simulations and tolerance analysis were conducted using Code V software, including various tolerance analyses, such as defocus, tilt, and decenter, and their related compensations. Two distinct Blu-ray pickup head system designs were examined in this study. In traditional Blu-ray pickup head system designs, the aperture stop is always set on objective lenses. In the study, the aperture stop is on the LC lens as a newly developed lens. The results revealed that an optical design with aperture stop set on the LC lens as an active compensation device successfully eliminated up to 57% of coma aberration compared with traditional optical designs so that this pickup head lens design will have more space for tolerance control.

Head Start Program and Cost Data Analysis: Final Report - Volume II.

ERIC Educational Resources Information Center

Cordes, Joseph; And Others

This second volume of the Head Start Program and Cost Data Analysis Final Report analyzes data from sources other than the Head Start Program Information Report (PIR). The report is divided into three sections: Distributional Impact of Head Start Financing, Pilot Study of Program Compliance, and Recommendations for Secondary Data Analysis. The…

Craniocervical Posture in Patients with Obstructive Sleep Apnea

PubMed Central

Piccin, Chaiane Facco; Pozzebon, Daniela; Scapini, Fabricio; Corrêa, Eliane Castilhos Rodrigues

2016-01-01

Introduction  Obstructive Sleep Apnea (OSA) is characterized by repeated episodes of upper airway obstruction during sleep. Objective  The objective of this study is to verify the craniofacial characteristics and craniocervical posture of OSA and healthy subjects, determining possible relationships with the apnea/hypopnea index (AHI). Methods  This case-control study evaluated 21 subjects with OSA, who comprised the OSA group (OSAG), and 21 healthy subjects, who constituted the control group (CG). Cephalometry analyzed head posture measurements, craniofacial measurements, and air space. Head posture was also assessed by means of photogrammetry. Results  The groups were homogeneous regarding gender (12 men and 9 women in each group), age (OSAG = 41.86 ± 11.26 years; GC = 41.19 ± 11.20 years), and body mass index (OSAG = 25.65 ± 2.46 kg/m2; CG = 24.72 ± 3.01 kg/m2). We found significant differences between the groups, with lower average pharyngeal space and greater distance between the hyoid bone and the mandibular plane in OSAG, when compared with CG. A positive correlation was found between higher head hyperextension and head anteriorization, with greater severity of OSA as assessed by AHI. Conclusion  OSAG subjects showed changes in craniofacial morphology, with lower average pharyngeal space and greater distance from the hyoid bone to the mandibular plane, as compared with healthy subjects. Moreover, in OSA subjects, the greater the severity of OSA, the greater the head hyperextension and anteriorization. PMID:27413397

High slew-rate head-only gradient for improving distortion in echo planar imaging: Preliminary experience.

PubMed

Tan, Ek T; Lee, Seung-Kyun; Weavers, Paul T; Graziani, Dominic; Piel, Joseph E; Shu, Yunhong; Huston, John; Bernstein, Matt A; Foo, Thomas K F

2016-09-01

To investigate the effects on echo planar imaging (EPI) distortion of using high gradient slew rates (SR) of up to 700 T/m/s for in vivo human brain imaging, with a dedicated, head-only gradient coil. Simulation studies were first performed to determine the expected echo spacing and distortion reduction in EPI. A head gradient of 42-cm inner diameter and with asymmetric transverse coils was then installed in a whole-body, conventional 3T magnetic resonance imaging (MRI) system. Human subject imaging was performed on five subjects to determine the effects of EPI on echo spacing and signal dropout at various gradient slew rates. The feasibility of whole-brain imaging at 1.5 mm-isotropic spatial resolution was demonstrated with gradient-echo and spin-echo diffusion-weighted EPI. As compared to a whole-body gradient coil, the EPI echo spacing in the head-only gradient coil was reduced by 48%. Simulation and in vivo results, respectively, showed up to 25-26% and 19% improvement in signal dropout. Whole-brain imaging with EPI at 1.5 mm spatial resolution provided good whole-brain coverage, spatial linearity, and low spatial distortion effects. Our results of human brain imaging with EPI using the compact head gradient coil at slew rates higher than in conventional whole-body MR systems demonstrate substantially improved image distortion, and point to a potential for benefits to non-EPI pulse sequences. J. Magn. Reson. Imaging 2016;44:653-664. © 2016 International Society for Magnetic Resonance in Medicine.

Metabolic and Regulatory Systems in Space Flight

NASA Technical Reports Server (NTRS)

1997-01-01

In this session, Session JP2, the discussion focuses on the following topics: The Dynamics of Blood Biochemical Parameters in Cosmonauts During Long-Term Space Flights; Efficiency of Functional Loading Test for Investigations of Metabolic Responses to Weightlessness; Human Cellular Immunity and Space Flight; Cytokine Production and Head-Down Tilt Bed Rest; Plasma and Urine Amino Acids During Human Space Flight; and DNA Fingerprinting, Applications to Space Microbiology.

Halley's Comet and Beyond.

ERIC Educational Resources Information Center

Sneider, Cary; DeVore, Edna

1986-01-01

Reviews software packages under these headings: (1) simulations of experiments; (2) space flight simulators; (3) planetariums; (4) space adventure games; and (5) drill and practice packages (designed for testing purposes or for helping students learn basic astronomy vocabulary). (JN)

14 CFR § 1201.103 - Administration.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Administration. § 1201.103 Section § 1201.103 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION STATEMENT OF ORGANIZATION AND GENERAL INFORMATION Introduction § 1201.103 Administration. (a) NASA is headed by an Administrator, who is...

Emergence of postural patterns as a function of vision and translation frequency

NASA Technical Reports Server (NTRS)

Buchanan, J. J.; Horak, F. B.; Peterson, B. W. (Principal Investigator)

1999-01-01

Emergence of postural patterns as a function of vision and translation frequency. We examined the frequency characteristics of human postural coordination and the role of visual information in this coordination. Eight healthy adults maintained balance in stance during sinusoidal support surface translations (12 cm peak to peak) in the anterior-posterior direction at six different frequencies. Changes in kinematic and dynamic measures revealed that both sensory and biomechanical constraints limit postural coordination patterns as a function of translation frequency. At slow frequencies (0.1 and 0.25 Hz), subjects ride the platform (with the eyes open or closed). For fast frequencies (1.0 and 1.25 Hz) with the eyes open, subjects fix their head and upper trunk in space. With the eyes closed, large-amplitude, slow-sway motion of the head and trunk occurred for fast frequencies above 0.5 Hz. Visual information stabilized posture by reducing the variability of the head's position in space and the position of the center of mass (CoM) within the support surface defined by the feet for all but the slowest translation frequencies. When subjects rode the platform, there was little oscillatory joint motion, with muscle activity limited mostly to the ankles. To support the head fixed in space and slow-sway postural patterns, subjects produced stable interjoint hip and ankle joint coordination patterns. This increase in joint motion of the lower body dissipated the energy input by fast translation frequencies and facilitated the control of upper body motion. CoM amplitude decreased with increasing translation frequency, whereas the center of pressure amplitude increased with increasing translation frequency. Our results suggest that visual information was important to maintaining a fixed position of the head and trunk in space, whereas proprioceptive information was sufficient to produce stable coordinative patterns between the support surface and legs. The CNS organizes postural patterns in this balance task as a function of available sensory information, biomechanical constraints, and translation frequency.

Heat Transfer and Fluid Dynamics Measurements in the Expansion Space of a Stirling Cycle Engine

NASA Technical Reports Server (NTRS)

Jiang, Nan; Simon, Terrence W.

2006-01-01

The heater (or acceptor) of a Stirling engine, where most of the thermal energy is accepted into the engine by heat transfer, is the hottest part of the engine. Almost as hot is the adjacent expansion space of the engine. In the expansion space, the flow is oscillatory, impinging on a two-dimensional concavely-curved surface. Knowing the heat transfer on the inside surface of the engine head is critical to the engine design for efficiency and reliability. However, the flow in this region is not well understood and support is required to develop the CFD codes needed to design modern Stirling engines of high efficiency and power output. The present project is to experimentally investigate the flow and heat transfer in the heater head region. Flow fields and heat transfer coefficients are measured to characterize the oscillatory flow as well as to supply experimental validation for the CFD Stirling engine design codes. Presented also is a discussion of how these results might be used for heater head and acceptor region design calculations.

Integration of Optical Coherence Tomography Scan Patterns to Augment Clinical Data Suite

NASA Technical Reports Server (NTRS)

Mason, S.; Patel, N.; Van Baalen, M.; Tarver, W.; Otto, C.; Samuels, B.; Koslovsky, M.; Schaefer, C.; Taiym, W.; Wear, M.;

Multilevel groundwater monitoring of hydraulic head and temperature in the eastern Snake River Plain aquifer, Idaho National Laboratory, Idaho, 2007-08

USGS Publications Warehouse

Fisher, Jason C.; Twining, Brian V.

2011-01-01

During 2007 and 2008, the U.S. Geological Survey, in cooperation with the U.S. Department of Energy, collected quarterly depth-discrete measurements of fluid pressure and temperature in six boreholes located in the eastern Snake River Plain aquifer of Idaho. Each borehole was instrumented with a multilevel monitoring system consisting of a series of valved measurement ports, packer bladders, casing segments, and couplers. Hydraulic heads (head) and water temperatures in boreholes were monitored at 86 hydraulically-isolated depth intervals located 448.0 to 1,377.6 feet below land surface. The calculation of head is most sensitive to fluid pressure and the altitude of the pressure transducer at each port coupling; it is least sensitive to barometric pressure and water temperature. An analysis of errors associated with the head calculation determined the accuracy of an individual head measurement at +/- 2.3 feet. Many of the sources of measurement error are diminished when considering the differences between two closely-spaced readings of head; therefore, a +/- 0.1 foot measurement accuracy was assumed for vertical head differences (and gradients) calculated between adjacent monitoring zones. Vertical head and temperature profiles were unique to each borehole, and were characteristic of the heterogeneity and anisotropy of the eastern Snake River Plain aquifer. The vertical hydraulic gradients in each borehole remained relatively constant over time with minimum Pearson correlation coefficients between head profiles ranging from 0.72 at borehole USGS 103 to 1.00 at boreholes USGS 133 and MIDDLE 2051. Major inflections in the head profiles almost always coincided with low permeability sediment layers. The presence of a sediment layer, however, was insufficient for identifying the location of a major head change in a borehole. The vertical hydraulic gradients were defined for the major inflections in the head profiles and were as much as 2.2 feet per foot. Head gradients generally were downward in boreholes USGS 133, 134, and MIDDLE 2050A, zero in boreholes USGS 103 and 132, and exhibited a reversal in direction in borehole MIDDLE 2051. Water temperatures in all boreholes ranged from 10.2 to 16.3 degrees Celsius. Boreholes USGS 103 and 132 are in an area of concentrated volcanic vents and fissures, and measurements show water temperature decreasing with depth. All other measurements in boreholes show water temperature increasing with depth. A comparison among boreholes of the normalized mean head over time indicates a moderately positive correlation.

Boeing CST-100 Starliner Seat Test

NASA Image and Video Library

2017-02-21

Engineers working with Boeing's CST-100 Starliner test the spacecraft's seat design in Mesa, Arizona, focusing on how the spacecraft seats would protect an astronaut's head, neck and spine during the 240-mile descent from the International Space Station. The company incorporated test dummies for a detailed analysis of impacts on a crew returning to earth. The human-sized dummies were equipped with sensitive instrumentation and secured in the seats for 30 drop tests at varying heights, angles, velocities and seat orientations in order to mimic actual landing conditions. High-speed cameras captured the footage for further analysis. The Starliner spacecraft is being developed in partnership with NASA's Commercial Crew Program.

46 CFR 190.20-10 - Location of crew spaces.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Location of crew spaces. 190.20-10 Section 190.20-10... crew spaces. (a) Crew quarters must not be located farther forward in the vessel than a vertical plane... of the deck head of the crew spaces may be below the deepest load line. (b) There must be no direct...

46 CFR 190.20-10 - Location of crew spaces.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Location of crew spaces. 190.20-10 Section 190.20-10... crew spaces. (a) Crew quarters must not be located farther forward in the vessel than a vertical plane... of the deck head of the crew spaces may be below the deepest load line. (b) There must be no direct...

46 CFR 190.20-10 - Location of crew spaces.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Location of crew spaces. 190.20-10 Section 190.20-10... crew spaces. (a) Crew quarters must not be located farther forward in the vessel than a vertical plane... of the deck head of the crew spaces may be below the deepest load line. (b) There must be no direct...

46 CFR 190.20-10 - Location of crew spaces.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Location of crew spaces. 190.20-10 Section 190.20-10... crew spaces. (a) Crew quarters must not be located farther forward in the vessel than a vertical plane... of the deck head of the crew spaces may be below the deepest load line. (b) There must be no direct...

46 CFR 190.20-10 - Location of crew spaces.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Location of crew spaces. 190.20-10 Section 190.20-10... crew spaces. (a) Crew quarters must not be located farther forward in the vessel than a vertical plane... of the deck head of the crew spaces may be below the deepest load line. (b) There must be no direct...

KSC-04PD-1084

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- After launch, the Delta II rocket carrying the Gravity Probe B spacecraft pitches over and starts heading downrange from Space Launch Complex 2 on Vandenberg AFB, Calif. Liftoff occurred at 9:57:24 a.m. PDT.

Fibre optic gyroscopes for space use

NASA Astrophysics Data System (ADS)

Faussot, Nicolas; Cottreau, Yann; Hardy, Guillaume; Simonpietri, Pascal; Gaiffe, Thierry

2017-11-01

Among the technologies available for gyroscopes usable in space, the Fibre Optic Gyroscope (FOG) technology appears to be the most suitable: no moving parts, very good lifetime, low power consumption, very low random walk, arbitrarily low angular resolution and very good behaviour in radiations and vacuum. Benefiting from more than ten years of experience with this technology, Ixsea (formerly the Navigation Division of Photonetics) is developing space FOG under both CNES and ESA contracts since many years. In the 1996-1998 period, two space FOG demonstrators in the 0,01°/h class were manufactured, including an optical head (optic and optoelectronic part) designed for space use and a standard ground electronics. Beyond the demonstration of the specified FOG performances, the behaviour of the optical head has been validated for use in typical space environment: vibrations, shocks, radiations (up to 50 krad) and thermal vacuum. Since the beginning of 1999, Ixsea is developing a space electronics in order to manufacture two complete space FOG. The first one entered in qualification in October. The second one will be delivered beginning of next year, it will be used in a CNES attitude measurement experiment (MAGI) onboard the FrenchBrazilian Microsatellite (FBM) partly dedicated to technology evaluation.

Formation and interaction of multiple coherent phase space structures in plasma

NASA Astrophysics Data System (ADS)

Kakad, Amar; Kakad, Bharati; Omura, Yoshiharu

2017-06-01

The head-on collision of multiple counter-propagating coherent phase space structures associated with the ion acoustic solitary waves (IASWs) in plasmas composed of hot electrons and cold ions is studied here by using one-dimensional Particle-in-Cell simulation. The chains of counter-propagating IASWs are generated in the plasma by injecting the Gaussian perturbations in the equilibrium electron and ion densities. The head-on collisions of the counter-propagating electron and ion phase space structures associated with IASWs are allowed by considering the periodic boundary condition in the simulation. Our simulation shows that the phase space structures are less significantly affected by their collision with each other. They emerge out from each other by retaining their characteristics, so that they follow soliton type behavior. We also find that the electrons trapped within these IASW potentials are accelerated, while the ions are decelerated during the course of their collisions.

Converse and Head at Space and Rocket Center

NASA Technical Reports Server (NTRS)

1972-01-01

Vincent W. Converse, high school student from Rockford, Illinois, discussed a mass measurement device he proposed for the Skylab mission with Dr. Robert Head of the Marshall Space Flight Center (MSFC) during his visit to the center. The lunar surface scene in the background is one of many space exhibits at the Alabama Space and Rocket Center in nearby Huntsville, Alabama. Converse was among 25 winners of a contest in which some 3,500 high school students proposed experiments for the following year's Skylab mission. The nationwide scientific competition was sponsored by the National Science Teachers Association and the National Aeronautics and Space Administration (NASA). The winning students, along with their parents and sponsor teachers, visited MSFC where they met with scientists and engineers, participated in design reviews for their experiments, and toured MSFC facilities. Of the 25 students, 6 did not see their experiments conducted on Skylab because the experiments were not compatible with Skylab hardware and timelines. Of the 19 remaining, 11 experiments required the manufacture of additional equipment.

Sherhart and Head at Space and Rocket Center

NASA Technical Reports Server (NTRS)

1972-01-01

Kirk M. Sherhart, high school student from Berkley, Michigan, discussed a his proposed Skylab experiment with Dr. Robert Head of the Marshall Space Flight Center (MSFC) during his visit to the center. The lunar surface scene in the background is one of many space exhibits at the Alabama Space and Rocket Center in nearby Huntsville, Alabama. Sherhart was among 25 winners of a contest in which some 3,500 high school students proposed experiments for the following year's Skylab mission. The nationwide scientific competition was sponsored by the National Science Teachers Association and the National Aeronautics and Space Administration (NASA). The winning students, along with their parents and sponsor teachers, visited MSFC where they met with scientists and engineers, participated in design reviews for their experiments, and toured MSFC facilities. Of the 25 students, 6 did not see their experiments conducted on Skylab because the experiments were not compatible with Skylab hardware and timelines. Of the 19 remaining, 11 experiments required the manufacture of additional equipment.

[Evaluation of diffuse cerebral atrophy in patients with a history of traumatic brain injury and its relation to cognitive deterioration].

PubMed

Narberhaus, A; Segarra-Castells, M D; Verger-Maestre, K; Serra-Grabulosa, J M; Salgado-Pineda, P; Bartomeus-Jené, F; Mercader-Sobrequés, J M

Diffuse damage secondary to traumatic brain injury (TBI) can be studied through volumetric analysis of several structures that are sensible to this kind of injury, such as corpus callosum, ventricular system, hippocampus, basal ganglia and the volume of cerebrospinal fluid spaces. Our aim is to describe how closed head injury (CHI) occurred in early years produce diffuse damage, and how this damage affects general cognitive functioning at long term. Initially the group of subjects was composed of 27 head injured children and adolescents following paediatric moderate to severe TBI. From this initial group we selected 15 patients without focal lesion, or in case of having suffered focal lesion, this was smaller than 2,600 mm3. These subjects were assessed by means of volumetric analysis of cerebrospinal fluid spaces, corpus callosum, hippocampus and caudate nucleus, comparing the results with a matched control group. We calculated the degree of general cognitive ability of these subjects through tests of intellectual, memory, frontal lobe and motor speed functioning. This study demonstrates that early CHI produce a volume decrease in all measured structures. Corpus callosum atrophy is the factor that better explains general cognitive impairment. Diffuse damage secondary to moderate to severe peadiatric TBI has long term effects on several cerebral structures and on cognitive performance. Corpus callosum atrophy is the best predictor for general cognitive impairment, compared with other affected structures.

A numerical investigation of head waves and leaky modes in fluid- filled boreholes.

USGS Publications Warehouse

Paillet, Frederick L.; Cheng, C.H.

1986-01-01

Although synthetic borehole seismograms can be computed for a wide range of borehole conditions, the physical nature of shear and compressional head waves in fluid-filled boreholes is poorly understood. Presents a series of numerical experiments designed to explain the physical mechanisms controlling head-wave propagation in boreholes. These calculations demonstrate the existence of compressional normal modes equivalent to shear normal modes, or pseudo-Rayleigh waves, with sequential cutoff frequencies spaced between the cutoff frequencies for the shear normal modes.-from Authors

[Head posture in orthodontics: physiopathology and clinical aspects 2].

PubMed

Caltabiano, M; Verzi, P; Scire Scappuzzo, G

1989-01-01

The Authors review in orthodontic respects present knowledges about head posture involvement in craniofacial morphogenesis and pathology. Relationships between craniofacial morphology, craniocervical posture, craniomandibular posture, cervical spine curvature, hyoid bone position and posture of whole body in space are shown, in attempt to explain conditions such as "forward head posture", mouth breathing and some occlusal disorders. Main methods to evaluate craniocervical relations on lateral skull radiographs are analysed. Pathogenesis of pain syndromes associated with abnormal craniocervical and craniomandibular mechanics are also briefly treated.

14 CFR § 1230.123 - Early termination of research support: Evaluation of applications and proposals.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Early termination of research support... termination of research support: Evaluation of applications and proposals. (a) The department or agency head... prescribed in applicable program requirements, when the department or agency head finds an institution has...

KSC-2012-3090

NASA Image and Video Library

2012-05-25

CAPE CANAVERAL, Fla. – Robotic vehicles take part in the racing portion of NASA's Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. Although much of the competition was based on a vehicle's ability to dig soil, the festivities also included head-to-head runs for the robotic craft. Photo credit: NASA/Jim Grossmann

Optical properties behavior of three optical filters and a mirror used in the internal optical head of a Raman laser spectrometer after exposed to proton radiation

NASA Astrophysics Data System (ADS)

Guembe, V.; Alvarado, C. G.; Fernández-Rodriguez, M.; Gallego, P.; Belenguer, T.; Díaz, E.

2017-11-01

The Raman Laser Spectrometer is one of the ExoMars Pasteur Rover's payload instruments that is devoted to the analytical analysis of the geochemistry content and elemental composition of the observed minerals provided by the Rover through Raman spectroscopy technique. One subsystem of the RLS instrument is the Internal Optical Head unit (IOH), which is responsible for focusing the light coming from the laser onto the mineral under analysis and for collecting the Raman signal emitted by the excited mineral. The IOH is composed by 4 commercial elements for Raman spectroscopy application; 2 optical filters provided by Iridian Spectral Technologies Company and 1 optical filter and 1 mirror provided by Semrock Company. They have been exposed to proton radiation in order to analyze their optical behaviour due to this hostile space condition. The proton irradiation test was performed following the protocol of LINES lab (INTA). The optical properties have been studied through transmittance, reflectance and optical density measurements, the final results and its influence on optical performances are presented.

Steam separator latch assembly

DOEpatents

Challberg, Roy C.; Kobsa, Irvin R.

1994-01-01

A latch assembly removably joins a steam separator assembly to a support flange disposed at a top end of a tubular shroud in a nuclear reactor pressure vessel. The assembly includes an annular head having a central portion for supporting the steam separator assembly thereon, and an annular head flange extending around a perimeter thereof for supporting the head to the support flange. A plurality of latches are circumferentially spaced apart around the head flange with each latch having a top end, a latch hook at a bottom end thereof, and a pivot support disposed at an intermediate portion therebetween and pivotally joined to the head flange. The latches are pivoted about the pivot supports for selectively engaging and disengaging the latch hooks with the support flange for fixedly joining the head to the shroud or for allowing removal thereof.

Steam separator latch assembly

DOEpatents

Challberg, R.C.; Kobsa, I.R.

1994-02-01

A latch assembly removably joins a steam separator assembly to a support flange disposed at a top end of a tubular shroud in a nuclear reactor pressure vessel. The assembly includes an annular head having a central portion for supporting the steam separator assembly thereon, and an annular head flange extending around a perimeter thereof for supporting the head to the support flange. A plurality of latches are circumferentially spaced apart around the head flange with each latch having a top end, a latch hook at a bottom end thereof, and a pivot support disposed at an intermediate portion therebetween and pivotally joined to the head flange. The latches are pivoted about the pivot supports for selectively engaging and disengaging the latch hooks with the support flange for fixedly joining the head to the shroud or for allowing removal thereof. 12 figures.

Adapted head- and eye-movement responses to added-head inertia

NASA Technical Reports Server (NTRS)

Gauthier, G. M.; Martin, B. J.; Stark, L. W.

1986-01-01

Adaptation to inertia added to the head was studied in men by mounting masses on a rigidly attached helmet until two- to ten-fold increases of inertia were produced, while an overhead suspension compensated for the weights. The observed changes in the eye and head movement coordination included increased head movement latencies, as well as changes in the eye movement amplitude, and later stabilizing alternate contractions of the neck muscles. Oscillopsia, or continual displacement or instability of the visual world, which is a symptom of a breakdown of space constancy, was prominent and consistent in the perceptual reports of the subjects. Although adaptation resulting from adding inertia to the head occurred much faster than that induced by adding prisms or lenses, it has similar perceptual and motor components that may be objectively studied in detail.

Multimodal integration in rostral fastigial nucleus provides an estimate of body movement

PubMed Central

Brooks, Jessica X.; Cullen, Kathleen E.

2012-01-01

The ability to accurately control posture and perceive self motion and spatial orientation requires knowledge of both the motion of the head and body. However, while the vestibular sensors and nuclei directly encode head motion, no sensors directly encode body motion. Instead, the convergence of vestibular and neck proprioceptive inputs during self-motion is generally believed to underlie the ability to compute body motion. Here, we provide evidence that the brain explicitly computes an internal estimate of body motion at the level of single cerebellar neurons. Neuronal responses were recorded from the rostral fastigial nucleus, the most medial of the deep cerebellar nuclei, during whole-body, body-under-head, and head-on-body rotations. We found that approximately half of the neurons encoded the motion of the body-in-space, while the other half encoded the motion of the head-in-space in a manner similar to neurons in the vestibular nuclei. Notably, neurons encoding body motion responded to both vestibular and proprioceptive stimulation (accordingly termed bimodal neurons). In contrast, neurons encoding head motion were only sensitive to vestibular inputs (accordingly termed unimodal neurons). Comparison of the proprioceptive and vestibular responses of bimodal neurons further revealed similar tuning in response to changes in head-on-body position. We propose that the similarity in nonlinear processing of vestibular and proprioceptive signals underlies the accurate computation of body motion. Furthermore, the same neurons that encode body motion (i.e., bimodal neurons) most likely encode vestibular signals in a body referenced coordinate frame, since the integration of proprioceptive and vestibular information is required for both computations. PMID:19710303

Self-organization of head-centered visual responses under ecological training conditions.

PubMed

Mender, Bedeho M W; Stringer, Simon M

2014-01-01

We have studied the development of head-centered visual responses in an unsupervised self-organizing neural network model which was trained under ecological training conditions. Four independent spatio-temporal characteristics of the training stimuli were explored to investigate the feasibility of the self-organization under more ecological conditions. First, the number of head-centered visual training locations was varied over a broad range. Model performance improved as the number of training locations approached the continuous sampling of head-centered space. Second, the model depended on periods of time where visual targets remained stationary in head-centered space while it performed saccades around the scene, and the severity of this constraint was explored by introducing increasing levels of random eye movement and stimulus dynamics. Model performance was robust over a range of randomization. Third, the model was trained on visual scenes where multiple simultaneous targets where always visible. Model self-organization was successful, despite never being exposed to a visual target in isolation. Fourth, the duration of fixations during training were made stochastic. With suitable changes to the learning rule, it self-organized successfully. These findings suggest that the fundamental learning mechanism upon which the model rests is robust to the many forms of stimulus variability under ecological training conditions.

Controlling stimulation strength and focality in electroconvulsive therapy via current amplitude and electrode size and spacing: comparison with magnetic seizure therapy.

PubMed

Deng, Zhi-De; Lisanby, Sarah H; Peterchev, Angel V

2013-12-01

Understanding the relationship between the stimulus parameters of electroconvulsive therapy (ECT) and the electric field characteristics could guide studies on improving risk/benefit ratio. We aimed to determine the effect of current amplitude and electrode size and spacing on the ECT electric field characteristics, compare ECT focality with magnetic seizure therapy (MST), and evaluate stimulus individualization by current amplitude adjustment. Electroconvulsive therapy and double-cone-coil MST electric field was simulated in a 5-shell spherical human head model. A range of ECT electrode diameters (2-5 cm), spacing (1-25 cm), and current amplitudes (0-900 mA) was explored. The head model parameters were varied to examine the stimulus current adjustment required to compensate for interindividual anatomical differences. By reducing the electrode size, spacing, and current, the ECT electric field can be more focal and superficial without increasing scalp current density. By appropriately adjusting the electrode configuration and current, the ECT electric field characteristics can be made to approximate those of MST within 15%. Most electric field characteristics in ECT are more sensitive to head anatomy variation than in MST, especially for close electrode spacing. Nevertheless, ECT current amplitude adjustment of less than 70% can compensate for interindividual anatomical variability. The strength and focality of ECT can be varied over a wide range by adjusting the electrode size, spacing, and current. If desirable, ECT can be made as focal as MST while using simpler stimulation equipment. Current amplitude individualization can compensate for interindividual anatomical variability.

KSC-06pd2879

NASA Image and Video Library

2006-12-22

KENNEDY SPACE CENTER, FLA. -- Sigmar Wittig, head of the DLR, the German Space Agency; Bill Gerstenmaier, NASA associate administrator for Space Operations; Mike Griffin, NASA administrator; Michel Tognini, head of the European Astronaut Center; and Bill Parsons, Kennedy Space Center deputy director, examine the thermal protection system tiles beneath Space Shuttle Discovery following the landing of mission STS-116 on Runway 15 at NASA Kennedy Space Center's Shuttle Landing Facility. During the STS-116 mission, three spacewalks attached the P5 integrated truss structure to the station, and completed the rewiring of the orbiting laboratory's power system. A fourth spacewalk retracted a stubborn solar array. Main gear touchdown was at 5:32 p.m. EST. Nose gear touchdown was at 5:32:12 p.m. and wheel stop was at 5:32:52 p.m. At touchdown -- nominally about 2,500 ft. beyond the runway threshold -- the orbiter is traveling at a speed ranging from 213 to 226 mph. Discovery traveled 5,330,000 miles, landing on orbit 204. Mission elapsed time was 12 days, 20 hours, 44 minutes and 16 seconds. This is the 64th landing at KSC. Photo credit: NASA/Kim Shiflett

Dragon Departure

NASA Image and Video Library

2012-10-28

ISS033-E-016529 (28 Oct. 2012) --- The SpaceX Dragon commercial cargo craft is pictured just prior to being released by the International Space Station's Canadarm2 robotic arm on Oct. 28 to allow it to head toward a splashdown in the Pacific Ocean.

Dragon Departure

NASA Image and Video Library

2012-10-28

ISS033-E-016526 (28 Oct. 2012) --- The SpaceX Dragon commercial cargo craft is pictured just prior to being released by the International Space Station's Canadarm2 robotic arm on Oct. 28 to allow it to head toward a splashdown in the Pacific Ocean.

Sensorimotor aspects of high-speed artificial gravity: II. The effect of head position on illusory self motion

NASA Technical Reports Server (NTRS)

Mast, F. W.; Newby, N. J.; Young, L. R.

2002-01-01

The effects of cross-coupled stimuli on the semicircular canals are shown to be influenced by the position of the subject's head with respect to gravity and the axis of rotation, but not by the subject's head position relative to the trunk. Seventeen healthy subjects made head yaw movements out of the horizontal plane while lying on a horizontal platform (MIT short radius centrifuge) rotating at 23 rpm about an earth-vertical axis. The subjects reported the magnitude and duration of the illusory pitch or roll sensations elicited by the cross-coupled rotational stimuli acting on the semicircular canals. The results suggest an influence of head position relative to gravity. The magnitude estimation is higher and the sensation decays more slowly when the head's final position is toward nose-up (gravity in the subject's head x-z-plane) compared to when the head is turned toward the side (gravity in the subject's head y-z-plane). The results are discussed with respect to artificial gravity in space and the possible role of pre-adaptation to cross-coupled angular accelerations on earth.

MAGNETIC RECORDING HEAD

DOEpatents

Merrill, L.C.

1958-06-17

An electromagetic recording head is described for simultaneous recording of a plurality of signals within a small space on a magnetically semsitized medium. Basically the head structure comprises a non-magnetic centerpiece provided with only first and second groups of spaced cut-out slots respectively on opposite sides of the centerpiece. The two groups of slots are in parallel alignment and the slots of one group are staggered with respect to the slots of the other group so that one slot is not directly opposite another slot. Each slot has a magnet pole piece disposed therein and cooperating with a second pole and coil to provide a magnetic flux gap at the upper end of the slot. As a tape is drawn over the upper end of the centerpiece the individual magnetic circuits are disposed along its width to provide means for simultaneously recording information on separate portions, tracks. of the tape.

Nanoscale modeling for ultrathin liquid films: Spreading and coupled layering

NASA Astrophysics Data System (ADS)

Phillips, David Michael

The hard disk drive (HDD) industry is currently experiencing a compound annual growth rate of 100% for the areal density. Current production drives have an areal density of 80 Gbit in-2, and drives with an areal density of 100 Gbit in-2 have been recently demonstrated. While much of this growth has been fueled by the development of new read/write heads, some of this gain was achieved by reducing the spacing between the heads and the magnetic media. This in turn reduces the spacing at the head-disk interface (HDI). The HDI in a HDD system consists of a slider, which contains the read/write heads, flying over the disk surface on an air bearing. The current designed separation distance, or fly height, is less than 10 nm. This spacing is expected to reduce to a mere 5 nm within the next few years. With the reduced fly height, intermittent contacts at the HDI become more probable. Only a thin lubricant film of perfluoropolyether (PFPE) and a sputtered carbon overcoat on the disk surface protect the slider and the stored data from mechanical and thermal damage. The PFPE film is quite thin, with a thickness of less than 2 nm or about a monolayer of molecules. During an HDI contact, the PFPE film is considered sacrificial and is often depleted in the contact area. In order to maintain adequate protection for the disk surface, PFPE molecules from the surrounding film must replenish the depleted area. This replenishment ability directly opposes the requirement that the PFPE film must not spin-off of the disk surface due to the disk rotation rate, which is as high as 10,000 RPM in current drives. To balance the PFPE films to sufficiently meet both requirements, HDD manufacturers functionalized the endgroups of the PFPE molecules to allow some portion of the lubricant film to reversibly bond with the disk overcoat. The result is a lubricant film that has a slower replenishment but does not spin-off. The work presented here focuses on the replenishment ability of thin films of liquid PFPE. The experimental analogue of replenishment is the one-dimensional spreading analysis. PFPEs with functional endgroups demonstrated coupled molecular layering and dewetting phenomena during the spreading analysis, while PFPEs with nonfunctional endgroups did not. All of the PFPE thin films spread via a diffusive process and had diffusion coefficients that depended on the local film thickness. A theoretical analysis is presented here for both the governing equation and the disjoining pressure driving force for the PFPE thin film spreading. For PFPEs with non-functional endgroups, a reasonable analysis is performed on the diffusion coefficient for two classes of film: submonolayer and multilayer. The diffusion coefficient of PFPEs with functional endgroups are qualitatively linked to the gradient of the film disjoining pressure. To augment this theory, both lattice-based and off-lattice Monte Carlo simulations are conducted for PFPE film models. The lattice-based model shows the existence of a critical functional endgroup interaction strength. It is also used to study the break-up of molecular layers for a spreading film via a fractal analysis. The off-lattice model is used to calculate the anisotropic pressure tensor for the model PFPE thin film and subsequently the film disjoining pressure. The model also qualitatively analyzes of the self diffusion in the film.

Space Shuttle Projects

NASA Image and Video Library

1984-04-24

The official mission insignia for the 41-D Space Shuttle flight features the Discovery - NASA's third orbital vehicle - as it makes its maiden voyage. The ghost ship represents the orbiter's namesakes which have figured prominently in the history of exploration. The Space Shuttle Discovery heads for new horizons to extend that proud tradition. Surnames for the crewmembers of NASA's eleventh Space Shuttle mission encircle the red, white, and blue scene.

Evaluation of inner-outer space distinction and verbal hallucinations in schizophrenia.

PubMed

Stephane, Massoud; Kuskowski, Michael; McClannahan, Kate; Surerus, Christa; Nelson, Katie

2010-09-01

Verbal hallucinations could result from attributing one's own inner speech to another. Inner speech is usually experienced in inner space, whereas hallucinations are often experienced in outer space. To clarify this paradox, we investigated schizophrenia patients' ability to distinguish between speech experienced in inner space, and speech experienced in outer space. 32 schizophrenia patients and 26 matched healthy controls underwent a two-stage experiment. First, they read sentences aloud or silently. Afterwards, they were required to distinguish between the sentences read aloud (experienced in outer space), the sentences read silently (experienced in inner space), and new sentences not previously read (no space coding). The sentences were in the first, second, or third person in equal proportions. Linear mixed models were used to investigate the effects of group, sentence location, pronoun, and hallucinations status. Schizophrenia patients were similar to controls in recognition capacity of sentences without space coding. They exhibited both inner-outer and outer-inner space confusion (they confused silently read sentences for sentences read aloud, and vice versa). Patients who experienced hallucinations inside their head were more likely to have outer-inner space bias. For speech generated by one's own brain, schizophrenia patients have bidirectional failure of inner-outer space distinction (inner-outer and outer-inner space biases); this might explain why hallucinations (abnormal inner speech) could be experienced in outer space. Furthermore, the direction of inner-outer space indistinction could determine the spatial location of the experienced hallucinations (inside or outside the head).

Mortality prediction of head Abbreviated Injury Score and Glasgow Coma Scale: analysis of 7,764 head injuries.

PubMed

Demetriades, Demetrios; Kuncir, Eric; Murray, James; Velmahos, George C; Rhee, Peter; Chan, Linda

2004-08-01

We assessed the prognostic value and limitations of Glasgow Coma Scale (GCS) and head Abbreviated Injury Score (AIS) and correlated head AIS with GCS. We studied 7,764 patients with head injuries. Bivariate analysis was performed to examine the relationship of GCS, head AIS, age, gender, and mechanism of injury with mortality. Stepwise logistic regression analysis was used to identify the independent risk factors associated with mortality. The overall mortality in the group of head injury patients with no other major extracranial injuries and no hypotension on admission was 9.3%. Logistic regression analysis identified head AIS, GCS, age, and mechanism of injury as significant independent risk factors of death. The prognostic value of GCS and head AIS was significantly affected by the mechanism of injury and the age of the patient. Patients with similar GCS or head AIS but different mechanisms of injury or ages had significantly different outcomes. The adjusted odds ratio of death in penetrating trauma was 5.2 (3.9, 7.0), p < 0.0001, and in the age group > or = 55 years the adjusted odds ratio was 3.4 (2.6, 4.6), p < 0.0001. There was no correlation between head AIS and GCS (correlation coefficient -0.31). Mechanism of injury and age have a major effect in the predictive value of GCS and head AIS. There is no good correlation between GCS and head AIS.

PRESIDENT KENNEDY TOURS CAPE CANAVERAL FACILITIES WITH DR. KURT H. DEBUS

NASA Technical Reports Server (NTRS)

1962-01-01

President Kennedy and Dr. Kurt Debus head for the car that will take them on a tour of our Nation's space facilities. The President, Vice President, and the Space Committee are among those being briefed at four locations on our space program. The tour includes Marshall Space Flight Center at Huntsville, Alabama, Atlantic Missile Range, Manned Space Flight Center, Houston, Texas, and McDonnell Aircraft at St. Louis, Mo.

STS-100 crew heads for the Astrovan to travel to Launch Pad 39A

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. - Leaving the Operations and Checkout Building, the STS-100 crew waves to well-wishers and heads to the Astrovan for transport to Launch Pad 39A. . Leading in front are Pilot Jeffrey S. Ashby (left) and Commander Kent V. Rominger (right). Behind them are (left to right) Mission Specialists Yuri Lonchakov and Chris A. Hadfield. Next are Mission Specialists Umberto Guidoni (left) and John L. Phillips (right). Following in the rear is Mission Specialist Scott E. Parazynski. An international crew, Guidoni represents the European Space Agency, Lonchakov the Russian Aviation and Space Agency and Hadfield the Canadian Space Agency. Space Shuttle Endeavour and its crew will deliver and integrate the Spacelab Logistics Pallet/Launch Deployment Assembly, which includes the Space Station Remote Manipulator System and the UHF Antenna. The mission includes two planned spacewalks for installation of the SSRMS, which will be performed by Parazynski and Hadfield. The mission is also the inaugural flight of Multi-Purpose Logistics Module Raffaello, carrying resupply stowage racks and resupply/return stowage platforms. Liftoff of Space Shuttle Endeavour on mission STS-100 is scheduled at 2:41 p.m. EDT April 19.

Brain stem omnipause neurons and the control of combined eye-head gaze saccades in the alert cat.

PubMed

Paré, M; Guitton, D

1998-06-01

When the head is unrestrained, rapid displacements of the visual axis-gaze shifts (eye-re-space)-are made by coordinated movements of the eyes (eye-re-head) and head (head-re-space). To address the problem of the neural control of gaze shifts, we studied and contrasted the discharges of omnipause neurons (OPNs) during a variety of combined eye-head gaze shifts and head-fixed eye saccades executed by alert cats. OPNs discharged tonically during intersaccadic intervals and at a reduced level during slow perisaccadic gaze movements sometimes accompanying saccades. Their activity ceased for the duration of the saccadic gaze shifts the animal executed, either by head-fixed eye saccades alone or by combined eye-head movements. This was true for all types of gaze shifts studied: active movements to visual targets; passive movements induced by whole-body rotation or by head rotation about stationary body; and electrically evoked movements by stimulation of the caudal part of the superior colliculus (SC), a central structure for gaze control. For combined eye-head gaze shifts, the OPN pause was therefore not correlated to the eye-in-head trajectory. For instance, in active gaze movements, the end of the pause was better correlated with the gaze end than with either the eye saccade end or the time of eye counterrotation. The hypothesis that cat OPNs participate in controlling gaze shifts is supported by these results, and also by the observation that the movements of both the eyes and the head were transiently interrupted by stimulation of OPNs during gaze shifts. However, we found that the OPN pause could be dissociated from the gaze-motor-error signal producing the gaze shift. First, OPNs resumed discharging when perturbation of head motion briefly interrupted a gaze shift before its intended amplitude was attained. Second, stimulation of caudal SC sites in head-free cat elicited large head-free gaze shifts consistent with the creation of a large gaze-motor-error signal. However, stimulation of the same sites in head-fixed cat produced small "goal-directed" eye saccades, and OPNs paused only for the duration of the latter; neither a pause nor an eye movement occurred when the same stimulation was applied with the eyes at the goal location. We conclude that OPNs can be controlled by neither a simple eye control system nor an absolute gaze control system. Our data cannot be accounted for by existing models describing the control of combined eye-head gaze shifts and therefore put new constraints on future models, which will have to incorporate all the various signals that act synergistically to control gaze shifts.

Experiences in Space Science.

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Washington, DC. Educational Programs Div.

This publication contains descriptions of space science activities that can be conducted with simple equipment. There are activities suitable for both elementary and secondary school children. Activities are placed under the headings: Astronomy, Atmosphere, Universal Gravitation, Aerodynamics, Guidance and Propulsion, Tracking and Communications,…

KSC-2009-6514

NASA Image and Video Library

2009-11-20

CAPE CANAVERAL, Fla. – In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, from left, Michael Suffredini, program manager, International Space Station, NASA; Secondino Brondolo, head of the Space Infrastructure, Thales Alenia Space Italy; and Bernardo Patti, head of International Space Station, Program Department, ESA, are photographed in front of node 3 for the International Space Station following a ceremony transferring the ownership of the node from the European Space Agency, or ESA, to NASA. Node 3 is named "Tranquility" after the Sea of Tranquility, the lunar landing site of Apollo 11. The payload for the STS-130 mission, Tranquility is a pressurized module that will provide room for many of the International Space Station's life support systems. The module was built for ESA by Thales Alenia Space in Turin, Italy. Attached to one end of Tranquility is a cupola, a unique work station with six windows on its sides and one on top. The cupola resembles a circular bay window and will provide a vastly improved view of the station's exterior. Just under 10 feet in diameter, the module will accommodate two crew members and portable workstations that can control station and robotic activities. The multi-directional view will allow the crew to monitor spacewalks and docking operations, as well as provide a spectacular view of Earth and other celestial objects. Space shuttle Endeavour's STS-130 mission is targeted to launch Feb. 4, 2010. Photo credit: NASA/Kim Shiflett

International Space Station from Space Shuttle Endeavour

NASA Technical Reports Server (NTRS)

2007-01-01

The crew of the Space Shuttle Endeavour took this spectacular image of the International Space Station during the STS118 mission, August 8-21, 2007. The image was acquired by an astronaut through one of the crew cabin windows, looking back over the length of the Shuttle. This oblique (looking at an angle from vertical, rather than straight down towards the Earth) image was acquired almost one hour after late inspection activities had begun. The sensor head of the Orbiter Boom Sensor System is visible at image top left. The entire Space Station is visible at image bottom center, set against the backdrop of the Ionian Sea approximately 330 kilometers below it. Other visible features of the southeastern Mediterranean region include the toe and heel of Italy's 'boot' at image lower left, and the western coastlines of Albania and Greece, which extend across image center. Farther towards the horizon, the Aegean and Black Seas are also visible. Featured astronaut photograph STS118-E-9469 was acquired by the STS-118 crew on August 19, 2007, with a Kodak 760C digital camera using a 28 mm lens, and is provided by the ISS Crew Earth Observations experiment and Image Science and Analysis Laboratory at Johnson Space Center.

Gaze pursuit responses in nucleus reticularis tegmenti pontis of head-unrestrained macaques.

PubMed

Suzuki, David A; Betelak, Kathleen F; Yee, Robert D

2009-01-01

Eye-head gaze pursuit-related activity was recorded in rostral portions of the nucleus reticularis tegmenti pontis (rNRTP) in alert macaques. The head was unrestrained in the horizontal plane, and macaques were trained to pursue a moving target either with their head, with the eyes stationary in the orbits, or with their eyes, with their head voluntarily held stationary in space. Head-pursuit-related modulations in rNRTP activity were observed with some cells exhibiting increases in firing rate with increases in head-pursuit frequency. For many units, this head-pursuit response appeared to saturate at higher frequencies (>0.6 Hz). The response phase re:peak head-pursuit velocity formed a continuum, containing cells that could encode head-pursuit velocity and those encoding head-pursuit acceleration. The latter cells did not exhibit head position-related activity. Sensitivities were calculated with respect to peak head-pursuit velocity and averaged 1.8 spikes/s/deg/s. Of the cells that were tested for both head- and eye-pursuit-related activity, 86% exhibited responses to both head- and eye-pursuit and therefore carried a putative gaze-pursuit signal. For these gaze-pursuit units, the ratio of head to eye response sensitivities averaged approximately 1.4. Pursuit eccentricity seemed to affect head-pursuit response amplitude even in the absence of a head position response per se. The results indicated that rNRTP is a strong candidate for the source of an active head-pursuit signal that projects to the cerebellum, specifically to the target-velocity and gaze-velocity Purkinje cells that have been observed in vermal lobules VI and VII.

Summary Report of Mission Acceleration Measurements for STS-62, Launched 4 March 1994

NASA Technical Reports Server (NTRS)

Rogers, Melissa J. B.; Delombard, Richard

1994-01-01

The second mission of the United States Microgravity Payload on-board the STS-62 mission was supported with three accelerometer instruments: the Orbital Acceleration Research Experiment (OARE) and two units of the Space Acceleration Measurements System (SAMS). The March 4, 1994 launch was the fourth successful mission for OARE and the ninth successful mission for SAMS. The OARE instrument utilizes a sensor for very low frequency measurements below one Hertz. The accelerations in this frequency range are typically referred to as quasisteady accelerations. One of the SAMS units had two remote triaxial sensor heads mounted on the forward MPESS structure between two furnance experiments, MEPHISTO and AADSF. These triaxial heads had low-pass filter cut-off frequencies at 10 and 25 Hz. The other SAMS unit utilized three remote triaxial sensor heads. Two of the sensor heads were mounted on the aft MPESS structure between the two experiments IDGE and ZENO. These triaxial heads had low-pass filter cut-off frequencies at 10 and 25 Hz. The third sensor head was mounted on the thermostat housing inside the IDGE experiment container. This triaxial head had a low-pass filter cut-off frequency at 5 Hz. This report is prepared to furnish interested experiment investigators with a guide to evaluating the acceleration environment during STS-62 and as a means of identifying areas which require further study. To achieve this purpose, various pieces of information are included, such as an overview of the STS-62 mission, a description of the accelerometer system flown on STS-62, some specific analysis of the accelerometer data in relation to the various mission activities, and an overview of the low-gravity environment during the entire mission. An evaluation form is included at the end of the report to solicit users' comments about the usefulness of this series of reports.

Virtual Acoustics: Evaluation of Psychoacoustic Parameters

NASA Technical Reports Server (NTRS)

Begault, Durand R.; Null, Cynthia H. (Technical Monitor)

1997-01-01

Current virtual acoustic displays for teleconferencing and virtual reality are usually limited to very simple or non-existent renderings of reverberation, a fundamental part of the acoustic environmental context that is encountered in day-to-day hearing. Several research efforts have produced results that suggest that environmental cues dramatically improve perceptual performance within virtual acoustic displays, and that is possible to manipulate signal processing parameters to effectively reproduce important aspects of virtual acoustic perception in real-time. However, the computational resources for rendering reverberation remain formidable. Our efforts at NASA Ames have been focused using a several perceptual threshold metrics, to determine how various "trade-offs" might be made in real-time acoustic rendering. This includes both original work and confirmation of existing data that was obtained in real rather than virtual environments. The talk will consider the importance of using individualized versus generalized pinnae cues (the "Head-Related Transfer Function"); the use of head movement cues; threshold data for early reflections and late reverberation; and consideration of the necessary accuracy for measuring and rendering octave-band absorption characteristics of various wall surfaces. In addition, a consideration of the analysis-synthesis of the reverberation within "everyday spaces" (offices, conference rooms) will be contrasted to the commonly used paradigm of concert hall spaces.

Orbital_ATK_Cygnus_OA9_Launch_2018_141_0800__655675

NASA Image and Video Library

2018-05-22

U.S. COMMERCIAL CARGO VEHICLE HEADS TO THE SPACE STATION------ The unpiloted Orbital ATK Cygnus cargo craft launched May 20 from Pad 0A at the Wallops Flight Facility, Virginia atop an Antares rocket, headed for a rendezvous with the International Space Station to deliver several tons of supplies and scientific experiments for the station residents. Dubbed the SS “J.R. Thompson” in honor of the late spacefaring manager for both NASA and Orbital ATK, Cygnus will be robotically captured and installed to the earth-facing port of the station’s Unity module for a two-month stay at the orbital outpost.

Pressurized water reactor flow skirt apparatus

DOEpatents

Kielb, John F.; Schwirian, Richard E.; Lee, Naugab E.; Forsyth, David R.

2016-04-05

A pressurized water reactor vessel having a flow skirt formed from a perforated cylinder structure supported in the lower reactor vessel head at the outlet of the downcomer annulus, that channels the coolant flow through flow holes in the wall of the cylinder structure. The flow skirt is supported at a plurality of circumferentially spaced locations on the lower reactor vessel head that are not equally spaced or vertically aligned with the core barrel attachment points, and the flow skirt employs a unique arrangement of hole patterns that assure a substantially balanced pressure and flow of the coolant over the entire underside of the lower core support plate.

Postural compensation for vestibular loss and implications for rehabilitation.

PubMed

Horak, Fay B

2010-01-01

This chapter summarizes the role of the vestibular system in postural control so that specific and effective rehabilitation can be designed that facilitates compensation for loss of vestibular function. Patients with bilateral or unilateral loss of peripheral vestibular function are exposed to surface perturbations to quantify automatic postural responses. Studies also evaluated the effects of audio- and vibrotactile-biofeedback to improve stability in stance and gait. The most important role of vestibular information for postural control is to control orientation of the head and trunk in space with respect to gravitoinertial forces, particularly when balancing on unstable surfaces. Vestibular sensory references are particularly important for postural control at high frequencies and velocities of self-motion, to reduce trunk drift and variability, to provide an external reference frame for the trunk and head in space; and to uncouple coordination of the trunk from the legs and the head-in-space from the body CoM. The goal of balance rehabilitation for patients with vestibular loss is to help patients 1) use remaining vestibular function, 2) depend upon surface somatosensory information as their primary postural sensory system, 3) learn to use stable visual references, and 4) identify efficient and effective postural movement strategies.

Feasibility of measuring dissolved carbon dioxide based on head space partial pressures

USGS Publications Warehouse

Watten, B.J.; Boyd, C.E.; Schwartz, M.F.; Summerfelt, S.T.; Brazil, B.L.

2004-01-01

We describe an instrument prototype that measures dissolved carbon dioxide (DC) without need for standard wetted probe membranes or titration. DC is calculated using Henry's Law, water temperature, and the steady-state partial pressure of carbon dioxide that develops within the instrument's vertical gas-liquid contacting chamber. Gas-phase partial pressures were determined with either an infrared detector (ID) or by measuring voltage developed by a pH electrode immersed in an isolated sodium carbonate solution (SC) sparged with recirculated head space gas. Calculated DC concentrations were compared with those obtained by titration over a range of DC (2, 4, 8, 12, 16, 20, 24, and 28mg/l), total alkalinity (35, 120, and 250mg/l as CaCO3), total dissolved gas pressure (-178 to 120 mmHg), and dissolved oxygen concentrations (7, 14, and 18 mg/l). Statistically significant (P < 0.001) correlations were established between head space (ID) and titrimetrically determined DC concentrations (R2 = 0.987-0.999, N = 96). Millivolt and titrimetric values from the SC solution tests were also correlated (P < 0.001, R 2 = 0.997, N = 16). The absolute and relative error associated with the use of the ID and SC solution averaged 0.9mg/l DC and 7.0% and 0.6 mg/l DC and 9.6%, respectively. The precision of DC estimates established in a second test series was good; coefficients of variation (100(SD/mean)) for the head space (ID) and titration analyses were 0.99% and 1.7%. Precision of the SC solution method was 1.3%. In a third test series, a single ID was coupled with four replicate head space units so as to permit sequential monitoring (15 min intervals) of a common water source. Here, appropriate gas samples were secured using a series of solenoid valves (1.6 mm bore) activated by a time-based controller. This system configuration reduced the capital cost per sample site from US$ 2695 to 876. Absolute error averaged 2.9, 3.1, 3.7, and 2.7 mg/ l for replicates 1-4 (N = 36) during a 21-day test period (DC range, 36-40 mg/l). The ID meter was then modified so as to provide for DO as well as DC measurements across components of an intensive fish production system. ?? 2003 Elsevier B.V. All rights reserved.

Comparison of cardiovascular function during the early hours of bed rest and space flight

NASA Technical Reports Server (NTRS)

Lathers, C. M.; Charles, J. B.

1994-01-01

This paper reviews the cardiovascular responses of six healthy male subjects to 6 hours in a 5 degrees head-down bed rest model of weightlessness, and compares these responses to those obtained when subjects were positioned in head-up tilts of 10 degrees, 20 degrees, and 42 degrees, simulating 1/6, 1/3, and 2/3 G, respectively. Thoracic fluid index, cardiac output, stroke volume, and peak flow were measured using impedance cardiography. Cardiac dimensions and volumes were determined from two-dimensional guided M-mode echocardiograms in the left lateral decubitus position at 0, 2, 4, and 6 hours. Cardiovascular response to a stand test were compared before and after bed rest. The impedance values were related to tilt angle for the first 2 hours of tilt; however, after 3 hours, at all four angles, values began to converge, indicating that cardiovascular homeostatic mechanisms seek a common adapted state, regardless of effective gravity level (tilt angle) up to 2/3 G. Echocardiography revealed that left ventricular end-diastolic and end-systolic volume, stroke volume, ejection fraction, heart rate, and cardiac output had returned to control values by hour 6 for all tilt angles. The lack of a significant immediate change in left ventricular end-diastolic volume, despite decrements in stroke volume (P < .05) and heart rate (not significant), indicates that multiple factors may play a role in the adaptation to simulated hypogravity. The echocardiography data indicated that no angle of tilt, whether head-down or head-up for 4 to 6 hours, mimicked exactly the changes in cardiovascular function recorded after 4 to 6 hours of space flight. Changes in left ventricular end-diastolic volume during space flight and tilt may be similar, but follow a different time course. Nevertheless, head-down tilt at 5 degrees for 6 hours mimics some (stroke volume, systolic and diastolic blood pressure, mean arterial blood pressure, and total resistance), but not all, of the changes occurring in an equivalent time of space flight. The magnitude of the change in the mean heart rate response to standing was greater after six hours of tilt at -5 degrees or 10 degrees. Thus, results from the stand test after 6 hours of bed rest at -5 degrees and 10 degrees, but not at 20 degrees or 42 degrees, are similar to those obtained after space flight.

Visual exploration during locomotion limited by fear of heights.

PubMed

Kugler, Günter; Huppert, Doreen; Eckl, Maria; Schneider, Erich; Brandt, Thomas

2014-01-01

Visual exploration of the surroundings during locomotion at heights has not yet been investigated in subjects suffering from fear of heights. Eye and head movements were recorded separately in 16 subjects susceptible to fear of heights and in 16 non-susceptible controls while walking on an emergency escape balcony 20 meters above ground level. Participants wore mobile infrared eye-tracking goggles with a head-fixed scene camera and integrated 6-degrees-of-freedom inertial sensors for recording head movements. Video recordings of the subjects were simultaneously made to correlate gaze and gait behavior. Susceptibles exhibited a limited visual exploration of the surroundings, particularly the depth. Head movements were significantly reduced in all three planes (yaw, pitch, and roll) with less vertical head oscillations, whereas total eye movements (saccade amplitudes, frequencies, fixation durations) did not differ from those of controls. However, there was an anisotropy, with a preference for the vertical as opposed to the horizontal direction of saccades. Comparison of eye and head movement histograms and the resulting gaze-in-space revealed a smaller total area of visual exploration, which was mainly directed straight ahead and covered vertically an area from the horizon to the ground in front of the feet. This gaze behavior was associated with a slow, cautious gait. The visual exploration of the surroundings by susceptibles to fear of heights differs during locomotion at heights from the earlier investigated behavior of standing still and looking from a balcony. During locomotion, anisotropy of gaze-in-space shows a preference for the vertical as opposed to the horizontal direction during stance. Avoiding looking into the abyss may reduce anxiety in both conditions; exploration of the "vertical strip" in the heading direction is beneficial for visual control of balance and avoidance of obstacles during locomotion.

Effects of space allowance on the behaviour of long-term housed shelter dogs.

PubMed

Normando, Simona; Contiero, Barbara; Marchesini, Giorgio; Ricci, Rebecca

2014-03-01

The aim of this study was to assess the effects of space allowance (4.5 m(2)/head vs. 9 m(2)/head) on the behaviour of shelter dogs (Canis familiaris) at different times of the day (from 10:30 to 13:30 vs. from 14:30 to 17:30), and the dogs' preference between two types of beds (fabric bed vs. plastic basket). Twelve neutered dogs (seven males and five females aged 3-8 years) housed in pairs were observed using a scan sampling recording method every 20 s for a total of 14,592 scans/treatment. An increase in space allowance increased general level of activity (risk ratio (RR)=1.34), standing (RR=1.37), positive social interactions (RR=2.14), visual exploration of the environment (RR=1.21), and vocalisations (RR=2.35). Dogs spent more time in the sitting (RR=1.39) or standing (RR=1.88) posture, in positive interactions (RR=1.85), and active visual exploration (RR=1.99) during the morning than in the afternoon. The dogs were more often observed in the fabric bed than in the plastic basket (53% vs. 15% of total scans, p<0.001). Results suggest that a 9.0 m(2)/head space allowance could be more beneficial to dogs than one of 4.5 m(2). Copyright © 2014 Elsevier B.V. All rights reserved.

Feller/bunchers in plantations thinnings: factors affecting productivity.

Treesearch

Sharon A. Winsauer; James A. Mattson; Michael A. Thompson

1984-01-01

Computer simulation was used to identify possible areas for improving the design and operation of feller/bunchers for thinning closely spaced plantations. Some of the variables considered were average stand diameter, tree spacing, thinning pattern, operational machine speeds, and shear head accumulating capacity.

Crewmembers sleeping in sleep restraints

NASA Image and Video Library

1997-08-29

STS085-327-026 (7 - 19 August 1997) --- Payload specialist Bjarni V. Tryggvason, representing the Canadian Space Agency (CSA), sleeps on the Space Shuttle Discovery's mid-deck floor. Tryggvason elected to not use a pillow, allowing his head to float freely in the Microgravity environment.

46 CFR 76.05-1 - Fire detecting systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... fitted with an automatic sprinkling system, except in relatively incombustible spaces. 2 Sprinkler heads....1 Offices, lockers, and isolated storerooms Electric, pneumatic, or automatic sprinkling1 Do.1 Public spaces None required with 20-minute patrol. Electric, pneumatic, or automatic sprinkling with 1...

46 CFR 76.05-1 - Fire detecting systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... fitted with an automatic sprinkling system, except in relatively incombustible spaces. 2 Sprinkler heads....1 Offices, lockers, and isolated storerooms Electric, pneumatic, or automatic sprinkling1 Do.1 Public spaces None required with 20-minute patrol. Electric, pneumatic, or automatic sprinkling with 1...

Pole pulling apparatus and method

DOEpatents

McIntire, Gary L.

1989-01-01

An apparatus for removal of embedded utility-type poles which removes the poles quickly and efficiently from their embedded position without damage to the pole or surrounding structures. The apparatus includes at least 2 piston/cylinder members equally spaced about the pole, and a head member affixed to the top of each piston. Elongation of the piston induces rotation of the head into the pole to increase the gripping action and reduce slippage. Repeated actuation and retraction of the piston and head member will "jack" the pole from its embedded position.

Human Health Countermeasures - Partial-Gravity Analogs Workshop

NASA Technical Reports Server (NTRS)

Barr, Yael; Clement, Gilles; Norsk, Peter

2016-01-01

The experimental conditions that were deemed the most interesting by the HHC Element lead scientists are those permitting studies of the long-term effects of exposure to (a) chronic rotation when supine or in head down tilt (ground-based); and (b) long-radius centrifugation (space based). It is interesting to note that chronic ground based slow rotation room studies have not been performed since the 1960's, when the USA and USSR were investigating the potential use of AG for long-duration space missions. On the other hand, the other partial gravity analogs, i.e., parabolic flight, HUT, suspension, and short-radius centrifugation, have been regularly used in the last three decades (see review in Clément et al. 2015). Based on the workshop evaluations and the scores by the HHC scientific disciplines indicated in tables 3 and 4, simulation of partial G between 0 and 1 should be prioritized as follows: Priority 1. Chronic space-based partial-G analogs: a. Chronic space-based long-radius centrifugation. The ideal scenario would be chronic long-radius centrifugation of cells, animals and humans in a translational research approach - ideally beyond low earth orbit under deep space environmental effects and at various rotations - to obtain different G-effects. In this scenario, all physiological systems could be evaluated and the relationship between physiological response and G level established. This would be the most integrative way of defining, for the first time ever, G-thresholds for each physiological system. b. Chronic space-based centrifugation of animals. Chronic centrifugation of rodents at various G levels in space would allow for determination of AG thresholds of protection for each physiological system. In this case, all physiological systems will be of interest. Intermittent centrifugation will be of secondary interest. c. Chronic space-based centrifugation of cell cultures (RWV). Bioreactor studies of cells and cell cultures of various tissues at various G levels would allow for intracellular investigations of the effects of partial-G. Priority 2. Acute, intermittent space based partial-G analogs: a. Acute, intermittent space-based short radius human centrifugation. Intermittent centrifugation of humans would allow determination of thresholds of AG for protection of astronaut health in space. Priority 3. Chronic ground-based partial-G analogs: a. Chronic centrifugation of supine or head-down tilted humans. b. Chronic head-up tilt in humans. c. Chronic head-out graded dry immersion in humans. d. Chronic partial suspension of rodents e. Chronic rotating bioreactor cell culture studies (RWV) Priority 4. Acute ground based partial-G analogs. a. Parabolic flights. Very acute and short term effects of G levels between 0 and 1 in humans for fast responding systems like cardiovascular and sensorimotor as well as for acute responses in cell cultures and animals. b. Other acute models as indicated in table 3.

Spermiogram and sperm head morphometry assessed by multivariate cluster analysis results during adolescence (12-18 years) and the effect of varicocele

PubMed Central

Vásquez, Fernando; Soler, Carles; Camps, Patricia; Valverde, Anthony; García-Molina, Almudena

2016-01-01

This work evaluates sperm head morphometric characteristics in adolescents from 12 to 18 years of age, and the effect of varicocele. Volunteers between 150 and 224 months of age (mean 191, n = 87), who had reached oigarche by 12 years old, were recruited in the area of Barranquilla, Colombia. Morphometric analysis of sperm heads was performed with principal component (PC) and discriminant analysis. Combining seminal fluid and sperm parameters provided five PCs: two related to sperm morphometry, one to sperm motility, and two to seminal fluid components. Discriminant analysis on the morphometric results of varicocele and nonvaricocele groups did not provide a useful classification matrix. Of the semen-related PCs, the most explanatory (40%) was related to sperm motility. Two PCs, including sperm head elongation and size, were sufficient to evaluate sperm morphometric characteristics. Most of the morphometric variables were correlated with age, with an increase in size and decrease in the elongation of the sperm head. For head size, the entire sperm population could be divided into two morphometric subpopulations, SP1 and SP2, which did not change during adolescence. In general, for varicocele individuals, SP1 had larger and more elongated sperm heads than SP2, which had smaller and more elongated heads than in nonvaricocele men. In summary, sperm head morphometry assessed by CASA-Morph and multivariate cluster analysis provides a better comprehension of the ejaculate structure and possibly sperm function. Morphometric analysis provides much more information than data obtained from conventional semen analysis. PMID:27751986

Automated recognition of rear seat occupants' head position using Kinect™ 3D point cloud.

PubMed

Loeb, Helen; Kim, Jinyong; Arbogast, Kristy; Kuo, Jonny; Koppel, Sjaan; Cross, Suzanne; Charlton, Judith

2017-12-01

Child occupant safety in motor-vehicle crashes is evaluated using Anthropomorphic Test Devices (ATD) seated in optimal positions. However, child occupants often assume suboptimal positions during real-world driving trips. Head impact to the seat back has been identified as one important injury causation scenario for seat belt restrained, head-injured children (Bohman et al., 2011). There is therefore a need to understand the interaction of children with the Child Restraint System to optimize protection. Naturalistic driving studies (NDS) will improve understanding of out-of-position (OOP) trends. To quantify OOP positions, an NDS was conducted. Families used a study vehicle for two weeks during their everyday driving trips. The positions of rear-seated child occupants, representing 22 families, were evaluated. The study vehicle - instrumented with data acquisition systems, including Microsoft Kinect™ V1 - recorded rear seat occupants in 1120 driving 26 trips. Three novel analytical methods were used to analyze data. To assess skeletal tracking accuracy, analysts recorded occurrences where Kinect™ exhibited invalid head recognition among a randomly-selected subset (81 trips). Errors included incorrect target detection (e.g., vehicle headrest) or environmental interference (e.g., sunlight). When head data was present, Kinect™ was correct 41% of the time; two other algorithms - filtering for extreme motion, and background subtraction/head-based depth detection are described in this paper and preliminary results are presented. Accuracy estimates were not possible because of their experimental nature and the difficulty to use a ground truth for this large database. This NDS tested methods to quantify the frequency and magnitude of head positions for rear-seated child occupants utilizing Kinect™ motion-tracking. This study's results informed recent ATD sled tests that replicated observed positions (most common and most extreme), and assessed the validity of child occupant protection on these typical CRS uses. Optimal protection in vehicles requires an understanding of how child occupants use the rear seat space. This study explored the feasibility of using Kinect™ to log positions of rear seated child occupants. Initial analysis used the Kinect™ system's skeleton recognition and two novel analytical algorithms to log head location. This research will lead to further analysis leveraging Kinect™ raw data - and other NDS data - to quantify the frequency/magnitude of OOP situations, ATD sled tests that replicate observed positions, and advances in the design and testing of child occupant protection technology. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights reserved.

Viability of barley seeds after long-term exposure to outer side of international space station

NASA Astrophysics Data System (ADS)

Sugimoto, Manabu; Ishii, Makoto; Mori, Izumi C.; Elena, Shagimardanova; Gusev, Oleg A.; Kihara, Makoto; Hoki, Takehiro; Sychev, Vladimir N.; Levinskikh, Margarita A.; Novikova, Natalia D.; Grigoriev, Anatoly I.

2011-09-01

Barley seeds were exposed to outer space for 13 months in a vented metal container without a climate control system to assess the risk of physiological and genetic mutation during long-term storage in space. The space-stored seeds (S0 generation), with an 82% germination rate in 50 seeds, lost about 20% of their weight after the exposure. The germinated seeds showed normal growth, heading, and ripening. The harvested seeds (S1 generation) also germinated and reproduced (S2 generation) as did the ground-stored seeds. The culm length, ear length, number of seed, grain weight, and fertility of the plants from the space-stored seeds were not significantly different from those of the ground-stored seeds in each of the S0 and S1 generation. Furthermore, the S1 and S2 space-stored seeds respectively showed similar β-glucan content to those of the ground-stored seeds. Amplified fragment length polymorphism analysis with 16 primer combinations showed no specific fragment that appears or disappears significantly in the DNA isolated from the barley grown from the space-stored seeds. Though these data are derived from nine S0 space-stored seeds in a single exposure experiment, the results demonstrate the preservation of barley seeds in outer space for 13 months without phenotypic or genotypic changes and with healthy and vigorous growth in space.

KSC-06pd2878

NASA Image and Video Library

2006-12-22

KENNEDY SPACE CENTER, FLA. -- Bill Gerstenmaier, NASA associate administrator for Space Operations; Sigmar Wittig, head of the DLR, the German Space Agency; Mike Griffin, NASA administrator; and Michel Tognini, head of the European Astronaut Center, examine the thermal protection system tiles beneath Space Shuttle Discovery following the landing of mission STS-116 on Runway 15 at NASA Kennedy Space Center's Shuttle Landing Facility. During the STS-116 mission, three spacewalks attached the P5 integrated truss structure to the station, and completed the rewiring of the orbiting laboratory's power system. A fourth spacewalk retracted a stubborn solar array. Main gear touchdown was at 5:32 p.m. EST. Nose gear touchdown was at 5:32:12 p.m. and wheel stop was at 5:32:52 p.m. At touchdown -- nominally about 2,500 ft. beyond the runway threshold -- the orbiter is traveling at a speed ranging from 213 to 226 mph. Discovery traveled 5,330,000 miles, landing on orbit 204. Mission elapsed time was 12 days, 20 hours, 44 minutes and 16 seconds. This is the 64th landing at KSC. Photo credit: NASA/Kim Shiflett

Fixed-head star tracker attitude updates on the Hubble Space Telescope

NASA Technical Reports Server (NTRS)

Nadelman, Matthew S.; Karl, Jeffrey B.; Hallock, Lou

1994-01-01

The Hubble Space Telescope (HST) was launched in April 1990 to begin observing celestial space to the edge of the universe. National Aeronautics and Space Administration (NASA) standard fixed-head star trackers (FHST's) are used operationally onboard the HST to regularly adjust ('update') the spacecraft attitude before the acquisition of guide stars for science observations. During the first 3 months of the mission, the FHST's updated the spacecraft attitude successfully only 85 percent of the time. During the other periods, the trackers were unable to find the selected stars -- either they failed to find any star, or worse, they selected incorrect stars and produced erroneous attitude updates. In July 1990, the HST project office at Goddard Space Flight Center (GSFC) requested that Computer Sciences Corporation (CSC) form an investigative 'tiger' team to examine these FHST update failures. This paper discusses the work of the FHST tiger team, describes the investigations that led the team to identify the sources of the errors, and defines the solutions that were subsequently developed, which ultimately increased the success rate of FHST updates to approximately 98 percent.

KSC-2009-6508

NASA Image and Video Library

2009-11-20

CAPE CANAVERAL, Fla. – In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, Michael Suffredini, program manager, International Space Station, NASA, addresses the invited guests at a ceremony transferring the ownership of node 3 for the International Space Station, looming in the background, from the European Space Agency, or ESA, to NASA. Seated, from left, are Bob Cabana, Kennedy Space Center director; Bernardo Patti, head of International Space Station, Program Department, ESA; and Secondino Brondolo, head of the Space Infrastructure, Thales Alenia Space Italy. Node 3 is named "Tranquility" after the Sea of Tranquility, the lunar landing site of Apollo 11. The payload for the STS-130 mission, Tranquility is a pressurized module that will provide room for many of the International Space Station's life support systems. The module was built for ESA by Thales Alenia Space in Turin, Italy. Attached to one end of Tranquility is a cupola, a unique work station with six windows on its sides and one on top. The cupola resembles a circular bay window and will provide a vastly improved view of the station's exterior. Just under 10 feet in diameter, the module will accommodate two crew members and portable workstations that can control station and robotic activities. The multi-directional view will allow the crew to monitor spacewalks and docking operations, as well as provide a spectacular view of Earth and other celestial objects. Space shuttle Endeavour's STS-130 mission is targeted to launch Feb. 4, 2010. Photo credit: NASA/Kim Shiflett

Program Review: The Lifetime Effects of Space Radiation in Rhesus Monkeys

DTIC Science & Technology

1990-03-01

6 Endometriosis ........................................................... 6 Hematology and Biochemistry...becomes an important consideration at higher proton energies. The head of the juvenile rhesus monkey could be examined in a CAT scan in order to...brain become important. Calculations based on data from CAT scans, which take into account the variation in size of the human head, should be made to

Simulator evaluation of display concepts for pilot monitoring and control of space shuttle approach and landing. Phase 2: Manual flight control

NASA Technical Reports Server (NTRS)

Gartner, W. B.; Baldwin, K. M.

1973-01-01

A study of the display requirements for final approach management of the space shuttle orbiter vehicle is presented. An experimental display concept, providing a more direct, pictorial representation of the vehicle's movement relative to the selected approach path and aiming points, was developed and assessed as an aid to manual flight path control. Both head-up, windshield projections and head-down, panel mounted presentations of the experimental display were evaluated in a series of simulated orbiter approach sequence. Data obtained indicate that the experimental display would enable orbiter pilots to exercise greater flexibility in implementing alternative final approach control strategies. Touchdown position and airspeed dispersion criteria were satisfied on 91 percent of the approach sequences, representing various profile and wind effect conditions. Flight path control and airspeed management satisfied operationally-relevant criteria for the two-segment, power-off orbiter approach and were consistently more accurate and less variable when the full set of experimental display elements was available to the pilot. Approach control tended to be more precise when the head-up display was used; however, the data also indicate that the head-down display would provide adequate support for the manual control task.

Head-Down Suspension Alters Stress-Responsiveness and Feedback Efficacy of 9a-Fludrocortisone in Rats

NASA Technical Reports Server (NTRS)

Horsley, C. J.; Evans, J.; Scribner, K. A.; Keil, L. C.; Dallman, M. F.

1994-01-01

9a-Fludrocortisone (9aFF) has been used to decrease orthostatic hypotension in astronauts whorl they return to earth after space flight. An earth-based model for weightlessness in space is head-down posture in man and rats. In these studies male rats were suspended head-down or not for 7 days and treated 14 and 2 hours prior to ether stress in the AM with 9aFF (20 micrograms i.u.) at -14 and -2 h or at -2 h with steroid and at -14 h with oil; controls were treated 2x with oil. Rats were decapitated 10 min after ether and ACTH and corticosterone (B) were measured. Both ACTH and B responses were greater in suspended than control rats under all three steroid conditions, and the percentage inhibition of ACTH by 9aFF was similar. Basal activity in the HPA over the 7 d suspension period was probably not elevated since adrenal and thymus weights did not differ in the ambulatory and head down groups. We conclude that headdown suspension facilitates acute stress-induced activity in the HPA axis, but that HPA axis sensitivity to corticosteroid feedback does not change.

Multiplex gas chromatography for use in space craft

NASA Technical Reports Server (NTRS)

Valentin, J. R.

1985-01-01

Gas chromatography is a powerful technique for the analysis of gaseous mixtures. Some limitations in this technique still exist which can be alleviated with multiplex gas chromatography (MGC). In MGC, rapid multiple sample injections are made into the column without having to wait for one determination to be finished before taking a new sample. The resulting data must then be reduced using computational methods such as cross correlation. In order to efficiently perform multiplexgas chromatography, experiments in the laboratory and on board future space craft, skills, equipment, and computer software were developed. Three new techniques for modulating, i.e., changing, sample concentrations were demonstrated by using desorption, decomposition, and catalytic modulators. In all of them, the need for a separate gas stream as the carrier was avoided by placing the modulator at the head of the column to directly modulate a sample stream. Finally, the analysis of an environmental sample by multiplex chromatography was accomplished by employing silver oxide to catalytically modulate methane in ambient air.

Vestibulospinal control of reflex and voluntary head movement

NASA Technical Reports Server (NTRS)

Boyle, R.; Peterson, B. W. (Principal Investigator)

2001-01-01

Secondary canal-related vestibulospinal neurons respond to an externally applied movement of the head in the form of a firing rate modulation that encodes the angular velocity of the movement, and reflects in large part the input "head velocity in space" signal carried by the semicircular canal afferents. In addition to the head velocity signal, the vestibulospinal neurons can carry a more processed signal that includes eye position or eye velocity, or both (see Boyle on ref. list). To understand the control signals used by the central vestibular pathways in the generation of reflex head stabilization, such as the vestibulocollic reflex (VCR), and the maintenance of head posture, it is essential to record directly from identified vestibulospinal neurons projecting to the cervical spinal segments in the alert animal. The present report discusses two key features of the primate vestibulospinal system. First, the termination morphology of vestibulospinal axons in the cervical segments of the spinal cord is described to lay the structural basis of vestibulospinal control of head/neck posture and movement. And second, the head movement signal content carried by the same class of secondary vestibulospinal neurons during the actual execution of the VCR and during self-generated, or active, rapid head movements is presented.

Retinal Evaluation Using Optical Coherence Tomography (OCT) During Deep Space Gateway Missions

NASA Astrophysics Data System (ADS)

Stenger, M. B.; Laurie, S. S.; Macias, B. R.; Barr, Y. R.

2018-02-01

Optical Coherence Tomography (OCT) imaging will be conducted before, during, and after Deep Space Gateway missions to evaluate changes in the retina and, in particular, the optic nerve head and surrounding structures. Additional parameters will be collected before and after flight.

Gaze Pursuit Responses in Nucleus Reticularis Tegmenti Pontis of Head-Unrestrained Macaques

PubMed Central

Suzuki, David A.; Betelak, Kathleen F.; Yee, Robert D.

2009-01-01

Eye-head gaze pursuit–related activity was recorded in rostral portions of the nucleus reticularis tegmenti pontis (rNRTP) in alert macaques. The head was unrestrained in the horizontal plane, and macaques were trained to pursue a moving target either with their head, with the eyes stationary in the orbits, or with their eyes, with their head voluntarily held stationary in space. Head-pursuit–related modulations in rNRTP activity were observed with some cells exhibiting increases in firing rate with increases in head-pursuit frequency. For many units, this head-pursuit response appeared to saturate at higher frequencies (>0.6 Hz). The response phase re:peak head-pursuit velocity formed a continuum, containing cells that could encode head-pursuit velocity and those encoding head-pursuit acceleration. The latter cells did not exhibit head position–related activity. Sensitivities were calculated with respect to peak head-pursuit velocity and averaged 1.8 spikes/s/deg/s. Of the cells that were tested for both head- and eye-pursuit–related activity, 86% exhibited responses to both head- and eye-pursuit and therefore carried a putative gaze-pursuit signal. For these gaze-pursuit units, the ratio of head to eye response sensitivities averaged ∼1.4. Pursuit eccentricity seemed to affect head-pursuit response amplitude even in the absence of a head position response per se. The results indicated that rNRTP is a strong candidate for the source of an active head-pursuit signal that projects to the cerebellum, specifically to the target-velocity and gaze-velocity Purkinje cells that have been observed in vermal lobules VI and VII. PMID:18987125

Subarachnoid, subdural and interdural spaces at the clival region: an anatomical study.

PubMed

Ayberk, Giyas; Ozveren, Mehmet Faik; Aslan, Sevil; Yaman, Mesut Emre; Yaman, Onur; Kayaci, Selim; Tekdemir, Ibrahim

2011-01-01

We aimed to show the significance of the anterior pontine membrane as a determining structure between the subdural and subarachnoid space in the clival region. Five adult cadaver heads and five cerebral hemispheres were used. The skull vault and hemipheres were removed by sectioning through the pontomesencephalic junction. Five other heads hemispheres were removed but the arachnoid membrane was protected and the cerebral side of the clival dura mater was dissected. In another specimen, the dural porus of the abducens nerve was sectioned for histological evaluation. Three cases of hematoma at the clivus were presented to support our findings. The anterior pontine membrane is the arachnoid membrane forming the anterior wall of the prepontine cistern with its lateral extension at the skull base. This membrane forms the subdural and subarachnoid spaces by forming a barrier between the clival dura mater and neurovascular structures of the brainstem. There were rigid fibrous trabeculations between both cerebral and periosteal dural layers forming the basilar plexus as the interdural space in the clivus. The anterior pontine membrane separates the subdural and subarachnoid spaces at the clival region. The hematomas of the clival region require to be evaluated with consideration given to the existance of the subdural space.

KENNEDY SPACE CENTER, FLA. - Standing in front of the Space Memorial Mirror at the KSC Visitor Complex, KSC Deputy Director Woodrow Whitlow Jr., Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott bow their heads in prayer during a memorial service remembering and honoring the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Scott is a former astronaut who flew on Columbia in 1997. The public was also invited to the memorial service.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - Standing in front of the Space Memorial Mirror at the KSC Visitor Complex, KSC Deputy Director Woodrow Whitlow Jr., Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott bow their heads in prayer during a memorial service remembering and honoring the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Scott is a former astronaut who flew on Columbia in 1997. The public was also invited to the memorial service.

Re-Entry Aeroheating Analysis of Tile-Repair Augers for the Shuttle Orbiter

NASA Technical Reports Server (NTRS)

Mazaheri, Ali R.; Wood, William A.

2007-01-01

Computational re-entry aerothermodynamic analysis of the Space Shuttle Orbiter s tile overlay repair (TOR) sub-assembly is presented. Entry aeroheating analyses are conducted to characterize the aerothermodynamic environment of the TOR and to provide necessary inputs for future TOR thermal and structural analyses. The TOR sub-assembly consists of a thin plate and several augers and spacers that serve as the TOR fasteners. For the computational analysis, the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) is used. A 5-species non-equilibrium chemistry model with a finite rate catalytic recombination model and a radiation equilibrium wall condition are used. It is assumed that wall properties are the same as reaction cured glass (RCG) properties with a surface emissivity of epsilon = 0.89. Surface heat transfer rates for the TOR and tile repair augers (TRA) are computed at a STS-107 trajectory point corresponding to Mach 18 free stream conditions. Computational results show that the average heating bump factor (BF), which is a ratio of local heat transfer rate to a design reference point located at the damage site, for the auger head alone is about 1.9. It is also shown that the average BF for the combined auger and washer heads is about 2.0.

Conical seat shut off valve

NASA Technical Reports Server (NTRS)

Farner, Bruce R. (Inventor)

2012-01-01

A valve includes a housing defining a bore having an inlet and extending along a longitudinal axis. A head is attached to the housing and defines a head passage having an outlet. A piston is disposed within the bore and includes a piston passage extending through the piston along the longitudinal axis. The piston is moveable between a closed position in which a sealing end of the piston abuts a seat of the head to close fluid communication through the piston passage and an open position in which the sealing end of the piston is axially spaced along the longitudinal axis from the seat of the head to permit fluid communication through the piston passage between the inlet and the outlet. The housing defines an equalizing chamber in fluid communication with the head passage for damping movement of the piston.

Channel heads in mountain catchments subject to human impact - The Skrzyczne range in Southern Poland

NASA Astrophysics Data System (ADS)

Wrońska-Wałach, Dominika; Żelazny, Mirosław; Małek, Stanisław; Krakowian, Katarzyna; Dąbek, Natalia

2018-05-01

Channel heads in mountain catchments are increasingly influenced by human activity. The disturbance of mountain headwater areas in moderate latitudes by the clearing of trees and the associated logging, road building and hydrotechnical constructions contribute to changes in the water cycle and consequently may induce a change in channel head development. Here we examine channel heads in the Beskid Śląski Mts., one of the areas most affected by ecological disaster in the Polish Flysch Carpathians. An ecological disaster associated with the decline of spruce trees in the 1980s and 1990s caused a substantial decrease (of about 50%) in the land area occupied by spruce forest in the Beskid Śląski Mts. As a result, headwater areas were subject to multidirectional changes in the environment. The purpose of this paper is to determine the detailed characteristics of channel heads currently developing in the analyzed headwater areas, as well as to identify independent factors that affect the evolution of channel heads. Geomorphological mapping was conducted in 2012 in the vicinity of springs in the study area. One-way ANOVA was used to determine the significance of differences between mean values calculated for groups identified based on: i) geomorphologic processes (hollows with rock veneer - h, spring niches - sn, gullies - g), ii) location vs. transformation of channel heads (forested areas vs., deforested areas with road constructions). Principal component analysis (PCA) was used to determine the structure and general patterns associated with relationships between the parameters of a channel head and its contribution area, as well as to identify and interpret new (orthogonal) spaces defined using distinct factors. As far as we know, this kind of approach has been never applied before. A total of 80 channel heads surrounding 104 springs were surveyed close to the main ridge in the study area. A total of 14 morphometric parameters were taken into account in this study. The analyzed landforms substantially differ from one another in relation to groups identified based on morphogenetic processes and with respect to time. Multidimensional PCA analysis made it possible to identify three independent, main factors that together explain 81.9% of total variance. It was concluded that the major factor today is human impact, which alters natural geomorphic processes. The second factor is connected with the type of water circulation. The third factor, which explains only 12.7% of variance, is a geologic factor defined in terms of structural integrity. Although our results are region-specific, at least some general conclusions may be drawn. The main general conclusion is that multidimensional human impact may lead to an increase in the fragmentation of mountain headwater areas over the long term.

Mechanism of Headward Fluid Shift During Exposure To Microgravity

NASA Technical Reports Server (NTRS)

Hargens, Alan R.; Parazynski, Scott E.; Watenpaugh, Donald E.; Aratow, Michael; Murthy, Gita; Kawai, Yasuaki

1994-01-01

A prominent feature of early cardiovascular adaptation to the microgravity of space flight is a shift of blood and tissue fluid from the lower body to the upper body. Symptoms of this fluid shift include facial edema, nasal congestion, and headache. Normally on Earth, the human body is exposed to hydrostatic (gravitational) blood pressure gradients during upright posture. In this posture, mean arterial pressures at head, heart, and foot levels are approximately 70, 100, and 200 mm Hg, respectively. Theoretically, all hydrostatic pressures within arteries and veins are lost during exposure to microgravity so that mean arterial pressure in all regions of the body is uniform and approximately equal to that at heart level (100 mm Hg). Acute studies of 60 head-down tilt (simulated microgravity on Earth) indicate that facial edema is caused by: 1) elevation of capillary blood pressure from 28 to 34 mm Hg, 2) reduction of blood colloid osmotic pressure 22 to 18 mm Hg, and 3) 50% increase of blood perfusion in tissues of the head. Furthermore, as compared to microvasculature in the feet, microvessels of the head have a low capacity to constrict and diminish local perfusion. Elevation of blood and tissue fluid pressures/flow in the head may also explain the higher headward bone density associated with long-term head-down tilt. These mechanistic studies of head-down tilt, along with a better understanding of the relative stresses involved with upright posture and lower body negative pressure, have facilitated development of physiologic countermeasures to maintain astronaut health during microgravity. Presently no exercise hardware is available to provide a blood pressure gradient from head to feet in space. However, recent studies in our laboratory suggest that treadmill exercise within lower body negative pressure provides equivalent or greater physiologic stress as compared to similar upright exercise on Earth.

Multiple sparse volumetric priors for distributed EEG source reconstruction.

PubMed

Strobbe, Gregor; van Mierlo, Pieter; De Vos, Maarten; Mijović, Bogdan; Hallez, Hans; Van Huffel, Sabine; López, José David; Vandenberghe, Stefaan

2014-10-15

We revisit the multiple sparse priors (MSP) algorithm implemented in the statistical parametric mapping software (SPM) for distributed EEG source reconstruction (Friston et al., 2008). In the present implementation, multiple cortical patches are introduced as source priors based on a dipole source space restricted to a cortical surface mesh. In this note, we present a technique to construct volumetric cortical regions to introduce as source priors by restricting the dipole source space to a segmented gray matter layer and using a region growing approach. This extension allows to reconstruct brain structures besides the cortical surface and facilitates the use of more realistic volumetric head models including more layers, such as cerebrospinal fluid (CSF), compared to the standard 3-layered scalp-skull-brain head models. We illustrated the technique with ERP data and anatomical MR images in 12 subjects. Based on the segmented gray matter for each of the subjects, cortical regions were created and introduced as source priors for MSP-inversion assuming two types of head models. The standard 3-layered scalp-skull-brain head models and extended 4-layered head models including CSF. We compared these models with the current implementation by assessing the free energy corresponding with each of the reconstructions using Bayesian model selection for group studies. Strong evidence was found in favor of the volumetric MSP approach compared to the MSP approach based on cortical patches for both types of head models. Overall, the strongest evidence was found in favor of the volumetric MSP reconstructions based on the extended head models including CSF. These results were verified by comparing the reconstructed activity. The use of volumetric cortical regions as source priors is a useful complement to the present implementation as it allows to introduce more complex head models and volumetric source priors in future studies. Copyright © 2014 Elsevier Inc. All rights reserved.

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

Yeo, Reuben J.; Dwivedi, Neeraj; Bhatia, Charanjit S., E-mail: elebcs@nus.edu.sg

Pole tip recession (PTR) is one of the major issues faced in magnetic tape storage technology, which causes an increase in the magnetic spacing and hence signal loss during data readback. Despite efforts to reduce the magnetic spacing, PTR, and surface wear on the heads by using protective overcoats, most of them either employ complex fabrication processes and approaches do not provide adequate protection to the head or are too thick (∼10–20 nm), especially for future high density tape storage. In this work, we discuss an approach to reduce the PTR and surface wear at the head by developing an ultrathinmore » ∼7 nm bilayer overcoat of silicon/silicon nitride (Si/SiN{sub x}) and carbon (C), which is totally fabricated by a cost-effective and industrial-friendly magnetron sputtering process. When compared with a monolithic C overcoat of similar thickness, the electrically insulating Si/SiN{sub x}/C bilayer overcoat was found to provide better wear protection for commercial tape heads, as demonstrated by Auger electron spectroscopic analyses after wear tests with commercial tape media. Although the microstructures of carbon in the monolithic and bilayer overcoats were similar, the improved wear durability of the bilayer overcoat was attributed to the creation of extensive interfacial bonding of Si and N with the C overcoat and the alumina-titanium carbide composite head substrate, as predicted by time-of-flight secondary ion mass spectrometry and confirmed by in-depth X-ray photoelectron spectroscopy analyses. This study highlights the pivotal role of enhanced interfaces and interfacial bonding in developing ultrathin yet wear-durable overcoats for tape heads.« less

KSC-00pp0056

NASA Image and Video Library

2000-01-14

During the First Florida Space Summit, held at the Kennedy Space Center Visitor Complex, NASA Administrator Dan Goldin and Florida Gov. Jeb Bush pose for a photo. The event, featuring a discussion on the future of space as it relates to the State of Florida and moderated by Center Director Roy Bridges, included other participants such as Senator Bob Graham, Rep. Dave Weldon, 45th Space Wing Commander Brig. Gen. Donald Pettit and heads of aerospace companies

KSC00pp0056

NASA Image and Video Library

2000-01-14

During the First Florida Space Summit, held at the Kennedy Space Center Visitor Complex, NASA Administrator Dan Goldin and Florida Gov. Jeb Bush pose for a photo. The event, featuring a discussion on the future of space as it relates to the State of Florida and moderated by Center Director Roy Bridges, included other participants such as Senator Bob Graham, Rep. Dave Weldon, 45th Space Wing Commander Brig. Gen. Donald Pettit and heads of aerospace companies

KSC-2009-6505

NASA Image and Video Library

2009-11-20

CAPE CANAVERAL, Fla. – In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, Kennedy Director Bob Cabana addresses the invited guests at a ceremony transferring the ownership of node 3 for the International Space Station, looming in the background, from the European Space Agency, or ESA, to NASA. Seated, from left, are William Dowdell, deputy for Operations, International Space Station and Spacecraft Processing, Kennedy; Bernardo Patti, head of International Space Station, Program Department, ESA; and Secondino Brondolo, head of the Space Infrastructure, Thales Alenia Space Italy. Node 3 is named "Tranquility" after the Sea of Tranquility, the lunar landing site of Apollo 11. The payload for the STS-130 mission, Tranquility is a pressurized module that will provide room for many of the International Space Station's life support systems. The module was built for ESA by Thales Alenia Space in Turin, Italy. Attached to one end of Tranquility is a cupola, a unique work station with six windows on its sides and one on top. The cupola resembles a circular bay window and will provide a vastly improved view of the station's exterior. Just under 10 feet in diameter, the module will accommodate two crew members and portable workstations that can control station and robotic activities. The multi-directional view will allow the crew to monitor spacewalks and docking operations, as well as provide a spectacular view of Earth and other celestial objects. Space shuttle Endeavour's STS-130 mission is targeted to launch Feb. 4, 2010. Photo credit: NASA/Kim Shiflett

KSC-2009-6509

NASA Image and Video Library

2009-11-20

CAPE CANAVERAL, Fla. – In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, Bernardo Patti, head of International Space Station, Program Department, ESA, addresses the invited guests at a ceremony transferring the ownership of node 3 for the International Space Station, looming in the background, from the European Space Agency, or ESA, to NASA. Seated, from left, are Bob Cabana, Kennedy Space Center director, and Secondino Brondolo, head of the Space Infrastructure, Thales Alenia Space Italy. Node 3 is named "Tranquility" after the Sea of Tranquility, the lunar landing site of Apollo 11. The payload for the STS-130 mission, Tranquility is a pressurized module that will provide room for many of the International Space Station's life support systems. The module was built for ESA by Thales Alenia Space in Turin, Italy. Attached to one end of Tranquility is a cupola, a unique work station with six windows on its sides and one on top. The cupola resembles a circular bay window and will provide a vastly improved view of the station's exterior. Just under 10 feet in diameter, the module will accommodate two crew members and portable workstations that can control station and robotic activities. The multi-directional view will allow the crew to monitor spacewalks and docking operations, as well as provide a spectacular view of Earth and other celestial objects. Space shuttle Endeavour's STS-130 mission is targeted to launch Feb. 4, 2010. Photo credit: NASA/Kim Shiflett

STS-66 landing at Edwards Air Force Base

NASA Technical Reports Server (NTRS)

1994-01-01

The drag chute is fully deployed as the Space Shuttle Atlantis heads toward a stop at Edwards Air Force Base in southern California, ending a successful 10 day, 22 hour and 34 minute space mission. Landing occured at 7:34 a.m. (PST), November 14, 1994.

Space for Mankind's Benefit.

ERIC Educational Resources Information Center

von Puttkamer, Jesco, Ed.; McCullough, Thomas J., Ed.

Presented are the proceedings of the first international Congress on "Space for Mankind's Benefit" organized by the Huntsville Association of Technical Societies and held November 15-19, 1971, at Huntsville, Alabama. Following introductory statements, a total of 45 articles read in 10 sessions are incorporated. The session headings are: Man in…

KSC-08pd3723

NASA Image and Video Library

2008-11-14

CAPE CANAVERAL, Fla. – Atop twin towers of flame, space shuttle Endeavour races past the lightning mast on Launch Pad 39A at NASA's Kennedy Space Center in Florida, heading into space on the STS-126 mission. Liftoff was on time at 7:55 p.m. EST. STS-126 is the 124th space shuttle flight and the 27th flight to the International Space Station. The mission will feature four spacewalks and work that will prepare the space station to house six crew members for long-duration missions. Photo courtesy of Scott Andrews

Predictors of rapid spontaneous resolution of acute subdural hematoma.

PubMed

Fujimoto, Kenji; Otsuka, Tadahiro; Yoshizato, Kimio; Kuratsu, Jun-ichi

2014-03-01

Acute subdural hematoma (ASDH) usually requires emergency surgical decompression, but rare cases exhibit rapid spontaneous resolution. The aim of this retrospective study was to identify factors predictive of spontaneous ASDH resolution. A total of 366 consecutive patients with ASDH treated between January 2006 and September 2012 were identified in our hospital database. Patients with ASDH clot thickness >10mm in the frontoparietotemporal region and showing a midline shift >10mm on the initial computed tomography (CT) scan were divided into two groups according to subsequent spontaneous resolution. Univariate and multivariate logistic regression analyses were used to identify factors predictive of rapid spontaneous ASDH resolution. Fifty-six ASDH patients met study criteria and 18 demonstrated rapid spontaneous resolution (32%). Majority of these patients were not operated because of poor prognosis/condition and in accordance to family wishes. Univariate analysis revealed significant differences in use of antiplatelet agents before head injury and in the incidence of a low-density band between the hematoma and inner wall of the skull bone on the initial CT. Use of antiplatelet agents before head injury (OR 19.6, 95% CI 1.5-260.1, p=0.02) and the low-density band on CT images (OR 40.3, 95% CI 3.1-520.2, p=0.005) were identified as independent predictive factors by multivariate analysis. Our analysis suggested that use of antiplatelet agents before head injury and a low-density band between the hematoma and inner skull bone on CT images (indicative of cerebrospinal fluid infusion into the subdural space) increase the probability of rapid spontaneous resolution. Copyright © 2013 Elsevier B.V. All rights reserved.

Reduced order modeling of head related transfer functions for virtual acoustic displays

NASA Astrophysics Data System (ADS)

Willhite, Joel A.; Frampton, Kenneth D.; Grantham, D. Wesley

2003-04-01

The purpose of this work is to improve the computational efficiency in acoustic virtual applications by creating and testing reduced order models of the head related transfer functions used in localizing sound sources. State space models of varying order were generated from zero-elevation Head Related Impulse Responses (HRIRs) using Kungs Single Value Decomposition (SVD) technique. The inputs to the models are the desired azimuths of the virtual sound sources (from minus 90 deg to plus 90 deg, in 10 deg increments) and the outputs are the left and right ear impulse responses. Trials were conducted in an anechoic chamber in which subjects were exposed to real sounds that were emitted by individual speakers across a numbered speaker array, phantom sources generated from the original HRIRs, and phantom sound sources generated with the different reduced order state space models. The error in the perceived direction of the phantom sources generated from the reduced order models was compared to errors in localization using the original HRIRs.

Multi-modality imaging findings of huge intrachoroidal cavitation and myopic peripapillary sinkhole.

PubMed

Chen, Yutong; Ma, Xiaoli; Hua, Rui

2018-02-02

Peripapillary intrachoroidal cavitation was described as the presence of an asymptomatic, well-circumscribed, yellow-orange, peripapillary lesion at the inferior border of the myopic conus in eyes with high myopia. A 66-year-old myopic Chinese man was enrolled and his multi-color imaging examination showed a well-circumscribed, caesious, peripapillary lesion coalesced with the optic nerve head vertically rotated and obliquely tilted, together with an inferotemporal sinkhole in the myopic conus. The optical coherence tomography images showed an intrachoroidal hyporeflective space, schisis, an intracavitary septum located below the retinal pigment epithelium and inserted beneath the optic nerve head, as well as a sinkhole between the peripapillary intrachoroidal cavitation and the vitreous space. Both myopic colobomas and sinkhole in myopic conus may contribute the coalescence of intrachoroidal cavitation with optic nerve head. These qualitative and quantitative new findings will be beneficial for understanding its pathomorphological mechanism, and the impact on optic nerve tissue of myopic patients.

Comparison of different patient positioning strategies to minimize shoulder girdle artifacts in head and neck CT.

PubMed

Wirth, Stefan; Meindl, Thomas; Treitl, Marcus; Pfeifer, Klaus-Jürgen; Reiser, Maximilian

2006-08-01

The purpose of this study was to analyze different patient positioning strategies for minimizing artifacts of the shoulder girdle in head and neck CT. Standardized CT examinations of three positioning groups were compared (P: patients pushed their shoulders downwards; D: similar optimization by a pulling device; N: no particular positioning optimization). Parameters analyzed were the length of the cervical spine not being superimposed by the shoulder girdle as well as noise in the supraclavicular space. In groups P and D, the portion of the cervical spine not superimposed was significantly larger than in group N (P: 10.4 cm; D: 10.6 cm; N: 8.5 cm). At the supraclavicular space, noise decreased significantly (P: 12.5 HU; D: 12.1 HU; N: 17.7 HU). No significant differences between the two position-optimized groups (P and D) were detected. Optimized shoulder positioning by the patient increases image quality in CT head and neck imaging. The use of a pulling device offers no additional advantages.

Subchondral cysts (geodes) in arthritic disorders: pathologic and radiographic appearance of the hip joint.

PubMed

Resnick, D; Niwayama, G; Coutts, R D

1977-05-01

A comprehensive study of femoral heads of patients and cadavers with osteoarthritis, rheumatoid arthritis, osteonecrosis, and calcium pyrophosphate dihydrate deposition disease allows insight into the radiographic and pathologic appearance of subchondral radiolucencies in these disorders. The term geode, rather than cyst or pseudocyst, may be a more appropriate decription of these lesions. In osteoarthritis, goedes occur on the pressure segment of the femoral head in association with loss of articular space; in rheumatoid arthritis, they are initially noted at the chondro-osseous junction and subsequently involve the entire femoral head. In osteonecrosis, geodes appear in the necrotic segment of the femoral head. In calcium pyrophosphate deposition disease, geodes resemble those in osteoarthritis but are larger, more numerous, and more widespread.

Computerized system for translating a torch head

NASA Technical Reports Server (NTRS)

Wall, W. A., Jr.; Ives, R. E.; Bruce, M. M., Jr.; Pryor, P. P., Jr.; Gard, L. H. (Inventor)

1978-01-01

The system provides a constant travel speed along a contoured workpiece. It has a driven skate characterized by an elongated bed, with a pair of independently pivoted trucks connected to the bed for support. The trucks are mounted on a contoured track of arbitrary configuration in a mutually spaced relation. An axially extensible torch head manipulator arm is mounted on the bed of the carriage and projects perpendicular from the midportion. The torch head is mounted at its distal end. A real-time computerized control drive subsystem is used to advance the skate along the track of a variable rate for maintaining a constant speed for the torch head tip, and to position the torch axis relative to a preset angle to the workpiece.

Structural Analyses of Stirling Power Convertor Heater Head for Long-Term Reliability, Durability, and Performance

NASA Technical Reports Server (NTRS)

Halford, Gary R.; Shah, Ashwin; Arya, Vinod K.; Krause, David L.; Bartolotta, Paul A.

2002-01-01

Deep-space missions require onboard electric power systems with reliable design lifetimes of up to 10 yr and beyond. A high-efficiency Stirling radioisotope power system is a likely candidate for future deep-space missions and Mars rover applications. To ensure ample durability, the structurally critical heater head of the Stirling power convertor has undergone extensive computational analyses of operating temperatures (up to 650 C), stresses, and creep resistance of the thin-walled Inconel 718 bill of material. Durability predictions are presented in terms of the probability of survival. A benchmark structural testing program has commenced to support the analyses. This report presents the current status of durability assessments.

KSC-99pc0114

NASA Image and Video Library

1999-01-25

KENNEDY SPACE CENTER, FLA. -- These wood storks stand in grassy patches near the waters of the Merritt Island National Wildlife Refuge at Kennedy Space Center. Known as "flint heads" and "gourd heads" because of their naked crowns, the wood stork is found throughout Florida and occasionally South Carolina and Texas, breeding in cypress and mangrove swamps. The refuge is a year-round home for wood storks, plus great blue herons, great egrets, cormorants, brown pelicans and other species of marsh and shore birds, as well as a wintering area for 23 species of migratory waterfowl. The 92,000-acre refuge is also habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles

Coal planer. [13 claims

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

Bahre, K.; Nowak, H.D.

1977-05-24

A coal planer for use in an underground mine gallery comprises a central unit, a pair of loading heads arranged spaced from and to opposite sides of the central unit and a pair of intermediate units, respectively, located between the central unit and the loading heads and linked to the latter and the central unit. Each of the intermediate units is provided with a plurality of planning knives arranged vertically spaced from each other for cutting coal from the mine face during reciprocation of the coal planer in a direction parallel to the mine face, and with a bottom knifemore » adapted to cut into the sole of the mine gallery. 13 claims, 5 figures.« less

KSC-2009-6510

NASA Image and Video Library

2009-11-20

CAPE CANAVERAL, Fla. – In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, Secondino Brondolo, head of the Space Infrastructure, Thales Alenia Space Italy, addresses the invited guests at a ceremony transferring the ownership of node 3 for the International Space Station from the European Space Agency, or ESA, to NASA. Seated, from left, are Bob Cabana, Kennedy Space Center director; Michael Suffredini, program manager, International Space Station, NASA; William Dowdell, deputy for Operations, International Space Station and Spacecraft Processing, Kennedy; and Bernardo Patti, head of International Space Station, Program Department, ESA. Node 3 is named "Tranquility" after the Sea of Tranquility, the lunar landing site of Apollo 11. The payload for the STS-130 mission, Tranquility is a pressurized module that will provide room for many of the International Space Station's life support systems. The module was built for ESA by Thales Alenia Space in Turin, Italy. Attached to one end of Tranquility is a cupola, a unique work station with six windows on its sides and one on top. The cupola resembles a circular bay window and will provide a vastly improved view of the station's exterior. Just under 10 feet in diameter, the module will accommodate two crew members and portable workstations that can control station and robotic activities. The multi-directional view will allow the crew to monitor spacewalks and docking operations, as well as provide a spectacular view of Earth and other celestial objects. Space shuttle Endeavour's STS-130 mission is targeted to launch Feb. 4, 2010. Photo credit: NASA/Kim Shiflett

System, Apparatus and Method Employing a Dual Head Laser

NASA Technical Reports Server (NTRS)

Coyle, Donald B. (Inventor); Stysley, Paul R. (Inventor); Poulios, Demetrios (Inventor)

2015-01-01

A system, apparatus and method employing a laser with a split-head, V-assembly gain material configuration. Additionally, the present invention is directed to techniques to better dissipate or remove unwanted energies in laser operations. The present invention is also directed to techniques for better collimated laser beams, with single spatial mode quality (TEM00), with improved efficiency, in extreme environments, such as in outer space.

Contrast-enhanced 3-dimensional SPACE versus MP-RAGE for the detection of brain metastases: considerations with a 32-channel head coil.

PubMed

Reichert, Miriam; Morelli, John N; Runge, Val M; Tao, Ai; von Ritschl, Ruediger; von Ritschl, Andreas; Padua, Abraham; Dix, James E; Marra, Michael J; Schoenberg, Stefan O; Attenberger, Ulrike I

2013-01-01

The aim of this study was to compare the detection of brain metastases at 3 T using a 32-channel head coil with 2 different 3-dimensional (3D) contrast-enhanced sequences, a T1-weighted fast spin-echo-based (SPACE; sampling perfection with application-optimized contrasts using different flip angle evolutions) sequence and a conventional magnetization-prepared rapid gradient-echo (MP-RAGE) sequence. Seventeen patients with 161 brain metastases were examined prospectively using both SPACE and MP-RAGE sequences on a 3-T magnetic resonance system. Eight healthy volunteers were similarly examined for determination of signal-to-noise ratio (SNR) values. Parameters were adjusted to equalize acquisition times between the sequences (3 minutes and 30 seconds). The order in which sequences were performed was randomized. Two blinded board-certified neuroradiologists evaluated the number of detectable metastatic lesions with each sequence relative to a criterion standard reading conducted at the Gamma Knife facility by a neuroradiologist with access to all clinical and imaging data. In the volunteer assessment with SPACE and MP-RAGE, SNR (10.3 ± 0.8 vs 7.7 ± 0.7) and contrast-to-noise ratio (0.8 ± 0.2 vs 0.5 ± 0.1) were statistically significantly greater with the SPACE sequence (P < 0.05). Overall, lesion detection was markedly improved with the SPACE sequence (99.1% of lesions for reader 1 and 96.3% of lesions for reader 2) compared with the MP-RAGE sequence (73.6% of lesions for reader 1 and 68.5% of lesions for reader 2; P < 0.01). A 3D T1-weighted fast spin echo sequence (SPACE) improves detection of metastatic lesions relative to 3D T1-weighted gradient-echo-based scan (MP-RAGE) imaging when implemented with a 32-channel head coil at identical scan acquisition times (3 minutes and 30 seconds).

Sensory processing in the vestibular nuclei during active head movements

NASA Technical Reports Server (NTRS)

Gdowski, G. T.; Boyle, R.; McCrea, R. A.; Peterson, B. W. (Principal Investigator)

2000-01-01

Many secondary vestibular neurons are sensitive to head on trunk rotation during reflex-induced and voluntary head movements. During passive whole body rotation the interaction of head on trunk signals related to the vestibulo-collic reflex with vestibular signals increases the rotational gain of many secondary vestibular neurons, including many that project to the spinal cord. In some units, the sensitivity to head on trunk and vestibular input is matched and the resulting interaction produces an output that is related to the trunk velocity in space. In other units the head on trunk inputs are stronger and the resulting interaction produces an output that is larger during the reflex. During voluntary head movements, inputs related to head on trunk movement combine destructively with vestibular signals, and often cancel the sensory reafferent consequences of self-generated movements. Cancellation of sensory vestibular signals was observed in all of the antidromically identified secondary vestibulospinal units, even though many of these units were not significantly affected by reflexive head on trunk movements. The results imply that the inputs to vestibular neurons related to head on trunk rotation during reflexive and voluntary movements arise from different sources. We suggest that the relative strength of reflexive head on trunk input to different vestibular neurons might reflect the different functional roles they have in controlling the posture of the neck and body.

Ground-Based Studies of Headward Fluid Shifts Related to Space Flight

NASA Technical Reports Server (NTRS)

Petersen, L. G.; Watkins, W.; Hargens, A. R.; Macias, B. R.

2017-01-01

Long-term space flight decreases visual acuity in more than 50% of astronauts with some reports of post-flight lumbar opening pressures up to 21 mmHg1. Loss of hydrostatic (gravitational) pressures in microgravity shifts blood, spinal fluid and tissue fluids towards the head, probably causing venous congestion and leading to symptoms compatible with chronically increased intracranial pressure (ICP). This is characterized as the Visual Impairment and Intracranial Pressure (VIIP) syndrome. Simulation of gravitational stress by application of Lower Body Negative Pressure (LBNP) is proposed as a means to reduce ICP and reestablish cerebral health in astronauts during long mission stay in space. We hypothesize that 50 mmHg of lower body negative pressure (LBNP) during supine and simulated intracranial hypertension by 15 deg head-down tilt (HDT) counteracts elevations in ICP and internal jugular vein crosssectional area (IJV CSA).

Angle-Dependent Distortions in the Perceptual Topology of Acoustic Space

PubMed Central

2018-01-01

By moving sounds around the head and asking listeners to report which ones moved more, it was found that sound sources at the side of a listener must move at least twice as much as ones in front to be judged as moving the same amount. A relative expansion of space in the front and compression at the side has consequences for spatial perception of moving sounds by both static and moving listeners. An accompanying prediction that the apparent location of static sound sources ought to also be distorted agrees with previous work and suggests that this is a general perceptual phenomenon that is not limited to moving signals. A mathematical model that mimics the measured expansion of space can be used to successfully capture several previous findings in spatial auditory perception. The inverse of this function could be used alongside individualized head-related transfer functions and motion tracking to produce hyperstable virtual acoustic environments. PMID:29764312

Supplement to the December 1974 Space Investigation Documentation System (SIDS) report

NASA Technical Reports Server (NTRS)

1975-01-01

A listing and brief description of spacecraft and experiments designed to update the December 1974 Space Investigations Documentation System (SIDS) report to March 31, 1975 was presented. The information is given in two sections. In the first, spacecraft and experiment descriptions are sorted by spacecraft common name. Within each spacecraft lising, experiments are sorted by the principal investigator's or team leader's last name. Each spacecraft entry heading contains the spacecraft common name, alternate names, NSSDC ID code, last reported state of the spacecraft, actual or planned launch date, weight, launch site and vehicle, sponsor, orbit parameters, personnel. Each experiment entry heading contains the experiment name, NSSDC ID code, last reported status, the Office of Space Science (OSS) division, the relevant SIDS disciplines, personnel. In the second, all spacecraft and experiment names described in the previous section and in the December 1974 report are sorted out.

Understanding the Effects of Spaceflight on Head-trunk Coordination During Walking and Obstacle Avoidance

NASA Technical Reports Server (NTRS)

Madansingh, S.; Bloomberg, J. J.

2014-01-01

Prolonged exposure to spaceflight conditions results in a battery of physiological changes, some of which contribute to sensorimotor and neurovestibular deficits. Upon return to Earth, functional performance changes are tested using the Functional Task Test (FTT), which includes an obstacle course to observe post-flight balance and postural stability, specifically during turning. The goal of this study was to quantify changes in movement strategies during turning events by observing the latency between head-and-trunk coordinated movements. It was hypothesized that subjects experiencing neurovestibular adaptations would exhibit head-to-trunk locking ('en bloc' movement) during turning, exhibited by a decrease in latency between head and trunk movement. FTT data samples were collected from 13 ISS astronauts and 26 male 70-day head down tilt bed rest subjects, including bed rest controls (10 BRC) and bed rest exercisers (16 BRE). Samples were analyzed three times pre-exposure, immediately post-exposure (0 or 1 day post) and 2-to-3 times during recovery from the unloading environment. Two 3D inertial measurements units (XSens MTx) were attached to subjects, one on the head and one on the upper back. This study focused primarily on the yaw movements about the subject's center of rotation. Time differences (latency) between head and trunk movement were averaged across a slalom obstacle portion, consisting of three turns (approximately three 60° turns). All participants were grouped as 'decreaser' or 'increaser,' relating to their change in head-to-trunk movement latency between pre- and post- environmental adaptation measures. Space flight unloading (ISS) showed a bimodal response between the 'increaser' and 'decreaser' group, while both bed rest control (BRC) and bed rest exercise (BRE) populations showed increased preference towards a 'decreaser' categorization, displaying greater head-trunk locking. It is clear that changes in movement strategies are adopted during exposure to an unloading environment. These results further the understanding of vestibular-somatosensory convergence and support the use of bed rest as an exclusionary model to better understand sensorimotor changes in space flight.

Spider-web amphiphiles as artificial lipid clusters: design, synthesis, and accommodation of lipid components at the air-water interface.

PubMed

Ariga, Katsuhiko; Urakawa, Toshihiro; Michiue, Atsuo; Kikuchi, Jun-ichi

2004-08-03

As a novel category of two-dimensional lipid clusters, dendrimers having an amphiphilic structure in every unit were synthesized and labeled "spider-web amphiphiles". Amphiphilic units based on a Lys-Lys-Glu tripeptide with hydrophobic tails at the C-terminal and a polar head at the N-terminal are dendrically connected through stepwise peptide coupling. This structural design allowed us to separately introduce the polar head and hydrophobic tails. Accordingly, we demonstrated the synthesis of the spider-web amphiphile series in three combinations: acetyl head/C16 chain, acetyl head/C18 chain, and ammonium head/C16 chain. All the spider-web amphiphiles were synthesized in satisfactory yields, and characterized by 1H NMR, MALDI-TOFMS, GPC, and elemental analyses. Surface pressure (pi)-molecular area (A) isotherms showed the formation of expanded monolayers except for the C18-chain amphiphile at 10 degrees C, for which the molecular area in the condensed phase is consistent with the cross-sectional area assigned for all the alkyl chains. In all the spider-web amphiphiles, the molecular areas at a given pressure in the expanded phase increased in proportion to the number of units, indicating that alkyl chains freely fill the inner space of the dendritic core. The mixing of octadecanoic acid with the spider-web amphiphiles at the air-water interface induced condensation of the molecular area. From the molecular area analysis, the inclusion of the octadecanoic acid bears a stoichiometric characteristic; i.e., the number of captured octadecanoic acids in the spider-web amphiphile roughly agrees with the number of branching points in the spider-web amphiphile.

Parallel processing of embossing dies with ultrafast lasers

NASA Astrophysics Data System (ADS)

Jarczynski, Manfred; Mitra, Thomas; Brüning, Stephan; Du, Keming; Jenke, Gerald

2018-02-01

Functionalization of surfaces equips products and components with new features like hydrophilic behavior, adjustable gloss level, light management properties, etc. Small feature sizes demand diffraction-limited spots and adapted fluence for different materials. Through the availability of high power fast repeating ultrashort pulsed lasers and efficient optical processing heads delivering diffraction-limited small spot size of around 10μm it is feasible to achieve fluences higher than an adequate patterning requires. Hence, parallel processing is becoming of interest to increase the throughput and allow mass production of micro machined surfaces. The first step on the roadmap of parallel processing for cylinder embossing dies was realized with an eight- spot processing head based on ns-fiber laser with passive optical beam splitting, individual spot switching by acousto optical modulation and an advanced imaging. Patterning of cylindrical embossing dies shows a high efficiency of nearby 80%, diffraction-limited and equally spaced spots with pitches down to 25μm achieved by a compression using cascaded prism arrays. Due to the nanoseconds laser pulses the ablation shows the typical surrounding material deposition of a hot process. In the next step the processing head was adapted to a picosecond-laser source and the 500W fiber laser was replaced by an ultrashort pulsed laser with 300W, 12ps and a repetition frequency of up to 6MHz. This paper presents details about the processing head design and the analysis of ablation rates and patterns on steel, copper and brass dies. Furthermore, it gives an outlook on scaling the parallel processing head from eight to 16 individually switched beamlets to increase processing throughput and optimized utilization of the available ultrashort pulsed laser energy.

Sensory Interactions for Head and Trunk Control in Space in Young and Older Adults During Normal and Narrow-Base Walking.

PubMed

Zhang, Fang; Deshpande, Nandini

2016-01-01

Fifteen young (20-30 years old) and 15 older (>65 years old) healthy participants were recruited to investigate age-related differences in head and trunk control under suboptimal vestibular conditions (galvanic vestibular stimulation, or GVS) and vision conditions during normal and narrow-based walking. Head-roll velocity decreased in the blurred-vision condition and marginally increased with GVS in older but not in young participants. Head pitch increased, whereas head-roll velocity decreased in narrow-base walking. Trunk pitch, trunk-pitch velocity, and gait speed increased with GVS, whereas trunk-pitch velocity and gait speed decreased in narrow-base walking. Marginally increased head-roll velocity in the older participants possibly suggests decreased integrative ability of the central nervous system in elderly people. The changes in head control during narrow-base walking may be an attempt to simplify the interpretation of the vestibular signal and increase otolith sensitivity. The complexity of controlling the trunk in the mediolateral direction was suggested by different strategies used for trunk control in different conditions.

Echocardiograms during six hours of bedrest at head-down and head-up tilt and during space flight

NASA Technical Reports Server (NTRS)

Lathers, C. M.; Riddle, J. M.; Mulvagh, S. L.; Mukai, C.; Diamandis, P. H.; Dussack, L. G.; Bungo, M. W.; Charles, J. B.

1993-01-01

Left ventricular end-diastolic volume increased after 4 1/2 to 6 hours of space flight, but was significantly decreased after 5 to 6 days of space flight. To determine the role of acute gravitational effects in this phenomenon, responses to a 6-hour bedrest model of 0 gravity (G; 5 degrees head-down tilt) were compared with those of fractional gravity loads of 1/6 G, 1/3 G, and 2/3 G by using head-up tilts of 10 degrees, 20 degrees, and 42 degrees, respectively. On 4 different days, six healthy male subjects were tilted at one of the four angles for 6 hours. Cardiac dimensions and volumes were determined from two-dimensional and M-mode echocardiograms in the left lateral decubitus position at control (0), 2, 4, and 6 hours. Stroke volume decreased with time (P < .05) for all tilt angles when compared with control. Ejection fraction (EF) at -5 degrees was greater than at +20 degrees and +42 degrees (not significant); EF at +10 degrees was greater than at +42 degrees (not significant). For the tilt angles of -5 degrees, +10 degrees, and +20 degrees, mean heart rate decreased during the first 2 hours, and returned to control or was slightly elevated above control (+20 degrees) by 6 hours (not significant). At the +42 degrees angle of tilt, heart rate was increased above control at hours 2, 4, and 6. There were no significant differences in cardiac output at any time point for any tilt angle.(ABSTRACT TRUNCATED AT 250 WORDS).

Endoscopic fringe projection for in-situ inspection of a sheet-bulk metal forming process

NASA Astrophysics Data System (ADS)

Matthias, Steffen; Kästner, Markus; Reithmeier, Eduard

2015-05-01

Sheet-bulk metal forming is a new production process capable of performing deep-drawing and massive forming steps in a single operation. However, due to the high forming forces of the forming process, continuous process control is required in order to detect wear on the forming tool before production quality is impacted. To be able to measure the geometry of the forming tool in the limited space of forming presses, a new inspection system is being developed within the SFB/TR 73 collaborative research center. In addition to the limited space, the process restricts the amount of time available for inspection. Existing areal optical measurement systems suffer from shadowing when measuring the tool's inner elements, as they cannot be placed in the limited space next to the tool, while tactile measurement systems cannot meet the time restrictions for measuring the areal geometries. The new inspection system uses the fringe projection optical measurement principle to capture areal geometry data from relevant parts of the forming tool in short time. Highresolution image fibers are used to connect the system's compact sensor head to a base unit containing both camera and projector of the fringe projection system, which can be positioned outside of the moving parts of the press. To enable short measurement times, a high intensity laser source is used in the projector in combination with a digital micro-mirror device. Gradient index lenses are featured in the sensor head to allow for a very compact design that can be used in the narrow space above the forming tool inside the press. The sensor head is attached to an extended arm, which also guides the image fibers to the base unit. A rotation stage offers the possibility to capture measurements of different functional elements on the circular forming tool by changing the orientation of the sensor head next to the forming tool. During operation of the press, the arm can be travelled out of the moving parts of the forming press. To further reduce the measurement times of the fringe projection system, the inverse fringe projection principle has been adapted to the system to detect geometry deviations in a single camera image. Challenges arise from vibrations of both the forming machine and the positioning stages, which are transferred via the extended arm to the sensor head. Vibrations interfere with the analysis algorithms of both encoded and inverse fringe projection and thus impair measurement accuracy. To evaluate the impact of vibrations on the endoscopic system, results of measurements of simple geometries under the influence of vibrations are discussed. The effect of vibrations is imitated by displacing the measurement specimen during the measurement with a linear positioning stage. The concept of the new inspection system is presented within the scope of the TR 73 demonstrational sheet-bulk metal forming process. Finally, the capabilities of the endoscopic fringe projection system are shown by measurements of gearing structures on a forming tool compared to a CAD-reference.

Expedition 26 Docking

NASA Image and Video Library

2010-12-18

Vitaly Davyidov, second from right, Deputy Head of the Russian Federal Space Agency, answers reporter’s questions during a Soyuz post-docking press conference at the Russian Mission Control Center in Korolev, Russia on Saturday, Dec. 18, 2010. The Soyuz TMA-20 docked to the International Space Station carrying Expedition 26 Soyuz Commander Dmitry Kondratyev, Flight Engineer Catherine Coleman and European Space Agency Flight Engineer Paolo Nespoli. Photo Credit: (NASA/Carla Cioffi)

STS-41D Mission Insignia

NASA Technical Reports Server (NTRS)

1984-01-01

The official mission insignia for the 41-D Space Shuttle flight features the Discovery - NASA's third orbital vehicle - as it makes its maiden voyage. The ghost ship represents the orbiter's namesakes which have figured prominently in the history of exploration. The Space Shuttle Discovery heads for new horizons to extend that proud tradition. Surnames for the crewmembers of NASA's eleventh Space Shuttle mission encircle the red, white, and blue scene.

41 CFR 102-74.75 - May Federal agencies sell tobacco products in vending machines in Government-owned and leased space?

Code of Federal Regulations, 2011 CFR

2011-01-01

... sell tobacco products in vending machines in Government-owned and leased space? 102-74.75 Section 102... Services § 102-74.75 May Federal agencies sell tobacco products in vending machines in Government-owned and... machines in Government-owned and leased space. The Administrator of GSA or the head of an Agency may...

Dreamchaser and VIP's

NASA Image and Video Library

2014-01-23

NASA and aerospace industry representatives tour facilities along Florida’s Space Coast prior to announcements made by Sierra Nevada Corporation, or SNC, Space Systems, to prepare for a November 2016 orbital flight of its Dream Chaser spacecraft. Walking along the 3.5-mile-long runway at Kennedy Space Center’s Shuttle Landing Facility are, from left, Frank DiBello, president and CEO of Space Florida Steve Lindsey, Dream Chaser program manager for SNC Space Systems Bob Cabana, director of NASA’s Kennedy Space Center Mark Sirangelo, corporate vice president and head of SNC Space Systems and Charlie Bolden, administrator of NASA.

Publications of the NASA space biology program for 1980 - 1984. [bibliographies

NASA Technical Reports Server (NTRS)

Pleasant, L. G. (Compiler); Solberg, J. L. (Compiler)

1984-01-01

A listing of 562 publications supported by the NASA Space Biology Program for the years 1980 to 1984 is presented. References are arranged under the headings which are plant gravitational research, animal gravitational research, and general. Keyword title indexes and a principal investigator listing are also included.

Are the Elderly Overhoused? Definitions of Space Utilization and Policy Implications.

ERIC Educational Resources Information Center

Lane, Terry Saunders; Feins, Judith D.

1985-01-01

Examined whether elderly-headed households live in dwellings too large for their needs. Demonstrates that most elderly households do not underutilize housing space. When homes of the elderly are on the market, new occupants include a wide range of household types, not just younger, larger families. (NRB)

Launch of the STS 51-F Challenger

NASA Image and Video Library

1985-07-29

51F-S-068 (29 July 1985) --- The Space Shuttle Challenger heads toward Earth-orbit with the Spacelab-2 experiment pallet and a team of astronauts and scientists onboard. This photograph was taken by Otis Imboden of the National Geographic Society for NASA from the press site at Kennedy Space Center (KSC).

Bipolarity in planarians is not induced by space travel.

PubMed

Sluys, Ronald; Stocchino, Giacinta A

2017-08-01

Available evidence strongly suggests that alternative, Earth-bound explanations should be sought first for the occurrence of a single bipolar planarian flatworm returning from space travel. Double-headed worms have been amply documented as arising under experimental conditions as well as spontaneously in stock cultures of planarians.

Human Factors Research Under Ground-Based and Space Conditions. Part 1

NASA Technical Reports Server (NTRS)

1997-01-01

Session TP2 includes short reports concerning: (1) Human Factors Engineering of the International space Station Human Research Facility; (2) Structured Methods for Identifying and Correcting Potential Human Errors in Space operation; (3) An Improved Procedure for Selecting Astronauts for Extended Space Missions; (4) The NASA Performance Assessment Workstation: Cognitive Performance During Head-Down Bedrest; (5) Cognitive Performance Aboard the Life and Microgravity Spacelab; and (6) Psychophysiological Reactivity Under MIR-Simulation and Real Micro-G.

Q&A: The space poet

NASA Astrophysics Data System (ADS)

Hoffman, Jascha

2011-11-01

Tracy K. Smith has her head in the stars. Thanks to her late father's job as an engineer on the Hubble Space Telescope, the US poet gathers inspiration from astrophysics and cosmology. Published this year, her third collection, Life on Mars, explores the future of human life, the great beyond and her father's death. As she prepares for a poetry reading at the Space Telescope Science Institute in Baltimore, Maryland, Smith talks about the limits of space and time.

Brush head composition, wear profile, and cleaning efficacy: an assessment of three electric brush heads using in vitro methods.

PubMed

Kaiser, Eva; Meyners, Michael; Markgraf, Dirk; Stoerkel, Ulrich; von Koppenfels, Roxana; Adam, Ralf; Soukup, Martin; Wehrbein, Heinrich; Erbe, Christina

2014-01-01

The objective of this research was to evaluate a current store brand (SB) brush head for composition/physical characteristics, Wear Index (WI), and cleaning efficacy versus the previous SB brush head refill design (SB control) and the Oral-B Precision Clean brush head (positive control, PC). This research consisted of three parts: 1) Analytical analysis using Fourier Transform Infrared (FT-IR) spectrometry to evaluate the chemical composition of the current SB brush head bristles relative to the SB control. In addition, physical parameters such as bristle count and diameter were determined. 2) Wear Index (WI) investigation to determine the Wear Index scores of in vitro-aged brush heads at four weeks (one month) and 13 weeks (three months) by a trained investigator. To "age" the brush heads, a robot system was used as a new alternative in vitro method to simulate aging by consumer use. 3) Robot testing to determine the cleaning performance of in vitro-aged brush heads, comparing one month-aged current SB brush heads with the SB control (one and three months-aged) and the PC brush heads (three months-aged) in a standardized fashion. 1) FT-IR analysis revealed that the chemical composition of the current and control SB refill brush heads is identical. In terms of physical parameters, the current SB brush head has 12% more bristles and a slightly oval brush head compared to the round brush head of the SB control. 2) Wear Index analysis showed there was no difference in the one month-aged current SB brush head versus the one month-aged SB control (1.67 vs. 1.50, p = 0.65) or versus the three months-aged PC brush head (1.67 vs. 1.50, p = 0.65). The one month-aged current SB brush head demonstrated statistically significantly less wear than the three months-aged SB control (1.67 vs. 2.67, p = 0.01). 3) Analysis of cleaning efficacy shows that the one month-aged current SB brush head had improved cleaning performance over the one month-aged SB control brush head (p < 0.05), despite no statistically significant difference in wear. Both the one month-aged current and control SB brush heads showed statistically significantly lower cleaning performance compared to the three months-aged PC brush heads (p < 0.01). While the current SB brush head showed improved cleaning over the SB control, it demonstrated significantly lower durability and cleaning in comparison to the PC brush head. Dental professionals should be aware of these differences, both in durability and in cleaning performance, when recommending brush heads to their patients.

Influence of gravity on the spatial orientation of eye nystagmus induced by unilateral lesion of horizontal semicircular canal.

PubMed

Pettorossi, V E; Ermanno, M; Pierangelo, E; Silvarosa, G

2000-03-01

The influence of gravity in the orientation and slow phase eye velocity of the ocular nystagmus following unilateral damage of the cupula in the ampulla of the horizontal semicircular canal (UHCD) was investigated. The nystagmus was analysed at different sagittal head positions using the x-y infrared eye monitor technique. The nystagmus was almost horizontal at 0 degrees head pitch angle and remained partially fixed in space when the head was pitched upward or downward. The reorientation gain of the slow and quick phases was high (about 0.75) within +/- 45 degrees of head pitch angle, but beyond this range, it decreased greatly. The gain value depended on the lesion extension to otolithic receptors. The absolute value of the slow phase eye velocity of UHCD nystagmus was also modified systematically by the head pitch, showing a reduction in the upward and an increase in the downward.

Directional Bias and Pheromone for Discovery and Coverage on Networks

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

Fink, Glenn A.; Berenhaut, Kenneth S.; Oehmen, Christopher S.

2012-09-11

Natural multi-agent systems often rely on “correlated random walks” (random walks that are biased toward a current heading) to distribute their agents over a space (e.g., for foraging, search, etc.). Our contribution involves creation of a new movement and pheromone model that applies the concept of heading bias in random walks to a multi-agent, digital-ants system designed for cyber-security monitoring. We examine the relative performance effects of both pheromone and heading bias on speed of discovery of a target and search-area coverage in a two-dimensional network layout. We found that heading bias was unexpectedly helpful in reducing search time andmore » that it was more influential than pheromone for improving coverage. We conclude that while pheromone is very important for rapid discovery, heading bias can also greatly improve both performance metrics.« less

Analysis of Retinal Vascular Branching in Human Subjects Undergoing 70-Day Head-Down Tilt by NASAs VESGEN Software

NASA Technical Reports Server (NTRS)

Parsons-Wingerter, Patricia; Vyas, Ruchi J.; Raghunandan, Sneha; Vu, Amanda C.; Zanello, Susana B.; Ploutz-Snyder, Rob; Taibbi, Giovanni; Vizzeri, Gianmarco

2016-01-01

Significant risks for visual impairment were discovered recently in astronauts following spaceflight, especially after long-duration missions. We hypothesize that microgravity-induced fluid shifts result in pathological changes within the retinal vasculature that precede visual and other ocular impairments. We therefore are analyzing retinal vessels in healthy subjects before and after head-down tilt (HDT), a ground-based microgravity analog with NASA's VESsel GENeration Analysis (VESGEN) software. Methods. Spectralis® infrared (IR) fundus images were collected from both eyes of 6 subjects before and after 70 days of bed rest at 6 degree HDT (NASA Campaign 11). For our retrospective study, branching patterns in arterial and venous trees are mapped by VESGEN into vessel branching generations (Gx) that are quantified by parameters such as densities of vessel length (Lv), area (Av), number (Nv) and fractal dimension (Df) as described previously for diabetic retinopathy (IOVS 51(1):498). Results are further assigned by VESGEN into groups of large (G1-3), medium (G4-6) and small (G=7) vessels. Results. All subjects remained asymptomatic throughout duration of HDT. To date, we have analyzed one IR image from each of the 12 eyes. Interestingly, two groups of the masked study population identified by VESGEN are distinguished by the presence or absence of small veins (G=7). For example, L=7 and Av=7 are 2.7+/-1.3 E-4 px/px2 and 7.2+/-3.6 E-4 px2/px2 in 6 retinas, but 0 in the other 6 retinas. Nonetheless, the space-filling properties of the entire venous trees were remarkably uniform by all parameters, such as Df = 1.56+/-0.02 for 6 retinas with G=7 and 1.55+/-0.02 for retinas without G=7. No small arteries (G=7) were detected. Conclusions. For our preliminary masked analysis, two groups of venous trees with and without small veins (G=7) were clearly revealed by VESGEN. Upon completing all images and unmasking the subject status of before and after HDT, we will determine whether differences in the presence or absence of small veins are important correlates, and perhaps reliable predictors, of other ocular and physiological adaptations to prolonged head-down tilt and microgravity. Clinical methods for examining adaptive microvascular remodeling in the retina to microgravity space flight are not currently established.

Recharge signal identification based on groundwater level observations.

PubMed

Yu, Hwa-Lung; Chu, Hone-Jay

2012-10-01

This study applied a method of the rotated empirical orthogonal functions to directly decompose the space-time groundwater level variations and determine the potential recharge zones by investigating the correlation between the identified groundwater signals and the observed local rainfall records. The approach is used to analyze the spatiotemporal process of piezometric heads estimated by Bayesian maximum entropy method from monthly observations of 45 wells in 1999-2007 located in the Pingtung Plain of Taiwan. From the results, the primary potential recharge area is located at the proximal fan areas where the recharge process accounts for 88% of the spatiotemporal variations of piezometric heads in the study area. The decomposition of groundwater levels associated with rainfall can provide information on the recharge process since rainfall is an important contributor to groundwater recharge in semi-arid regions. Correlation analysis shows that the identified recharge closely associates with the temporal variation of the local precipitation with a delay of 1-2 months in the study area.

Development of a flexible γ-ray detector using a liquid scintillation light guide (LSLG).

PubMed

Nomura, Kiyoshi; Yunoki, Akira; Hara, Masayuki; Morito, Yuko; Fujishima, Akira

2018-04-10

A flexible γ detector using a liquid scintillation light guide (LSLG) was developed. The analyzed pulse height (PHA) spectrum depended on the diameter, length and scintillator concentration of the LSLG, and the distance of a γ ray irradiation point from the head of photomultiplier tube (PMT). From the analysis of PHA spectrum, it was found that the count ratio of two divided channel regions linearly decreases as the distance from the PMT head increases. It was further found that the radiation dose rate can be estimated by setting the flexible LSLG tube to a circular shape since the count rate is proportional to the dose rate measured by a conventional NaI (Tl) scintillation detector. Therefore, a flexible and long LSLG detector using a single PMT is useful for determination of the dose rate and has a potential to detect local contaminations in a certain narrow space. Copyright © 2018. Published by Elsevier Ltd.

Trajectory Planning by Preserving Flexibility: Metrics and Analysis

NASA Technical Reports Server (NTRS)

Idris, Husni R.; El-Wakil, Tarek; Wing, David J.

2008-01-01

In order to support traffic management functions, such as mitigating traffic complexity, ground and airborne systems may benefit from preserving or optimizing trajectory flexibility. To help support this hypothesis trajectory flexibility metrics have been defined in previous work to represent the trajectory robustness and adaptability to the risk of violating safety and traffic management constraints. In this paper these metrics are instantiated in the case of planning a trajectory with the heading degree of freedom. A metric estimation method is presented based on simplifying assumptions, namely discrete time and heading maneuvers. A case is analyzed to demonstrate the estimation method and its use in trajectory planning in a situation involving meeting a time constraint and avoiding loss of separation with nearby traffic. The case involves comparing path-stretch trajectories, in terms of adaptability and robustness along each, deduced from a map of estimated flexibility metrics over the solution space. The case demonstrated anecdotally that preserving flexibility may result in enhancing certain factors that contribute to traffic complexity, namely reducing proximity and confrontation.

Scientific guidelines for preservation of samples collected from Mars

NASA Technical Reports Server (NTRS)

Gooding, James L. (Editor)

1990-01-01

The maximum scientific value of Martian geologic and atmospheric samples is retained when the samples are preserved in the conditions that applied prior to their collection. Any sample degradation equates to loss of information. Based on detailed review of pertinent scientific literature, and advice from experts in planetary sample analysis, number values are recommended for key parameters in the environmental control of collected samples with respect to material contamination, temperature, head-space gas pressure, ionizing radiation, magnetic fields, and acceleration/shock. Parametric values recommended for the most sensitive geologic samples should also be adequate to preserve any biogenic compounds or exobiological relics.

Ranging in Human Sonar: Effects of Additional Early Reflections and Exploratory Head Movements

PubMed Central

Wallmeier, Ludwig; Wiegrebe, Lutz

2014-01-01

Many blind people rely on echoes from self-produced sounds to assess their environment. It has been shown that human subjects can use echolocation for directional localization and orientation in a room, but echo-acoustic distance perception - e.g. to determine one's position in a room - has received little scientific attention, and systematic studies on the influence of additional early reflections and exploratory head movements are lacking. This study investigates echo-acoustic distance discrimination in virtual echo-acoustic space, using the impulse responses of a real corridor. Six blindfolded sighted subjects and a blind echolocation expert had to discriminate between two positions in the virtual corridor, which differed by their distance to the front wall, but not to the lateral walls. To solve this task, participants evaluated echoes that were generated in real time from self-produced vocalizations. Across experimental conditions, we systematically varied the restrictions for head rotations, the subjects' orientation in virtual space and the reference position. Three key results were observed. First, all participants successfully solved the task with discrimination thresholds below 1 m for all reference distances (0.75–4 m). Performance was best for the smallest reference distance of 0.75 m, with thresholds around 20 cm. Second, distance discrimination performance was relatively robust against additional early reflections, compared to other echolocation tasks like directional localization. Third, free head rotations during echolocation can improve distance discrimination performance in complex environmental settings. However, head movements do not necessarily provide a benefit over static echolocation from an optimal single orientation. These results show that accurate distance discrimination through echolocation is possible over a wide range of reference distances and environmental conditions. This is an important functional benefit of human echolocation, which may also play a major role in the calibration of auditory space representations. PMID:25551226

Roles of gravitational cues and efference copy signals in the rotational updating of memory saccades.

PubMed

Klier, Eliana M; Angelaki, Dora E; Hess, Bernhard J M

2005-07-01

Primates are able to localize a briefly flashed target despite intervening movements of the eyes, head, or body. This ability, often referred to as updating, requires extraretinal signals related to the intervening movement. With active roll rotations of the head from an upright position it has been shown that the updating mechanism is 3-dimensional, robust, and geometrically sophisticated. Here we examine whether such a rotational updating mechanism operates during passive motion both with and without inertial cues about head/body position in space. Subjects were rotated from either an upright or supine position, about a nasal-occipital axis, briefly shown a world-fixed target, rotated back to their original position, and then asked to saccade to the remembered target location. Using this paradigm, we tested subjects' abilities to update from various tilt angles (0, +/-30, +/-45, +/-90 degrees), to 8 target directions and 2 target eccentricities. In the upright condition, subjects accurately updated the remembered locations from all tilt angles independent of target direction or eccentricity. Slopes of directional errors versus tilt angle ranged from -0.011 to 0.15, and were significantly different from a slope of 1 (no compensation for head-in-space roll) and a slope of 0.9 (no compensation for eye-in-space roll). Because the eyes, head, and body were fixed throughout these passive movements, subjects could not use efference copies or neck proprioceptive cues to assess the amount of tilt, suggesting that vestibular signals and/or body proprioceptive cues suffice for updating. In the supine condition, where gravitational signals could not contribute, slopes ranged from 0.60 to 0.82, indicating poor updating performance. Thus information specifying the body's orientation relative to gravity is critical for maintaining spatial constancy and for distinguishing body-fixed versus world-fixed reference frames.

Marshall Space Flight Center head development program

NASA Technical Reports Server (NTRS)

Harrer, Jim

1994-01-01

This report summarizes the results of the candidate head evaluation for the new long-life magnetic head per the SOW of Contract No. NAS8-39407, MSFC Head Development Program. The original program plans were to test a candidate head, fabricate a new head, then qualify the new head. These activities were scheduled to be carried out between March 1993 and March 1994. The program was halted after the evaluation of the candidate head by NAS8-39407 Amendment No. 4. MSFC has provided and authorized the use the MARS-2000 SRB QUAL Recorder PN 10400-0677-801 - Serial Number 200004 (Datatape PN 591000 - Serial Number 1004), Reproduce Amplifier Module (RAM) Datatape PN 533040 - Serial Number 2006, associated cables, and magnetic tape on special SRB/DFI tapered reels to Datatape for this program. All the testing that has been done for the candidate head evaluation was done at Datatape's facility in Pasadena,CA. The testing was performed in a Class 100,000 particle counts clean room at ambient temperature, except for the thermal testing which was conducted in a different area at Datatape. The Performance Verification Test Procedure PVT-11004-4 (PVT) and Acceptance Test Procedure ATP-11004-09 (ATP) procedures were used when tests were conducted on the recorder.

MRI Sequences in Head & Neck Radiology - State of the Art.

PubMed

Widmann, Gerlig; Henninger, Benjamin; Kremser, Christian; Jaschke, Werner

2017-05-01

Background  Magnetic resonance imaging (MRI) has become an essential imaging modality for the evaluation of head & neck pathologies. However, the diagnostic power of MRI is strongly related to the appropriate selection and interpretation of imaging protocols and sequences. The aim of this article is to review state-of-the-art sequences for the clinical routine in head & neck MRI and to describe the evidence for which medical question these sequences and techniques are useful. Method  Literature review of state-of-the-art sequences in head & neck MRI. Results and Conclusion  Basic sequences (T1w, T2w, T1wC+) and fat suppression techniques (TIRM/STIR, Dixon, Spectral Fat sat) are important tools in the diagnostic workup of inflammation, congenital lesions and tumors including staging. Additional sequences (SSFP (CISS, FIESTA), SPACE, VISTA, 3D-FLAIR) are used for pathologies of the cranial nerves, labyrinth and evaluation of endolymphatic hydrops in Menière's disease. Vessel and perfusion sequences (3D-TOF, TWIST/TRICKS angiography, DCE) are used in vascular contact syndromes, vascular malformations and analysis of microvascular parameters of tissue perfusion. Diffusion-weighted imaging (EPI-DWI, non-EPI-DWI, RESOLVE) is helpful in cholesteatoma imaging, estimation of malignancy, and evaluation of treatment response and posttreatment recurrence in head & neck cancer. Understanding of MRI sequences and close collaboration with referring physicians improves the diagnostic confidence of MRI in the daily routine and drives further research in this fascinating image modality. Key Points:   · Understanding of MRI sequences is essential for the correct and reliable interpretation of MRI findings.. · MRI protocols have to be carefully selected based on relevant clinical information.. · Close collaboration with referring physicians improves the output obtained from the diagnostic possibilities of MRI.. Citation Format · Widmann G, Henninger B, Kremser C et al. MRI Sequences in Head & Neck Radiology - State of the Art. Fortschr Röntgenstr 2017; 189: 413 - 422. © Georg Thieme Verlag KG Stuttgart · New York.

Restoration of MRI Data for Field Nonuniformities using High Order Neighborhood Statistics

PubMed Central

Hadjidemetriou, Stathis; Studholme, Colin; Mueller, Susanne; Weiner, Michael; Schuff, Norbert

2007-01-01

MRI at high magnetic fields (> 3.0 T ) is complicated by strong inhomogeneous radio-frequency fields, sometimes termed the “bias field”. These lead to nonuniformity of image intensity, greatly complicating further analysis such as registration and segmentation. Existing methods for bias field correction are effective for 1.5 T or 3.0 T MRI, but are not completely satisfactory for higher field data. This paper develops an effective bias field correction for high field MRI based on the assumption that the nonuniformity is smoothly varying in space. Also, nonuniformity is quantified and unmixed using high order neighborhood statistics of intensity cooccurrences. They are computed within spherical windows of limited size over the entire image. The restoration is iterative and makes use of a novel stable stopping criterion that depends on the scaled entropy of the cooccurrence statistics, which is a non monotonic function of the iterations; the Shannon entropy of the cooccurrence statistics normalized to the effective dynamic range of the image. The algorithm restores whole head data, is robust to intense nonuniformities present in high field acquisitions, and is robust to variations in anatomy. This algorithm significantly improves bias field correction in comparison to N3 on phantom 1.5 T head data and high field 4 T human head data. PMID:18193095

Computed tomography angiography reveals the crime instrument – case report

PubMed Central

Banaszek, Anna; Guziński, Maciej; Sąsiadek, Marek

2010-01-01

Summary Background: The development of multislice CT technology enabled imaging of post-traumatic brain lesions with isotropic resolution, which led to unexpected results in the presented case Case Report: An unconscious, 49-year-old male with a suspected trauma underwent a routine CT examination of the head, which revealed an unusual intracerebral bleeding and therefore was followed by CT angiography (CTA). The thorough analysis of CTA source scans led to the detection of the bleeding cause. Conclusions: The presented case showed that a careful analysis of a CT scan allows not only to define the extent of pathological lesions in the intracranial space but it also helps to detect the crime instrument, which is of medico-legal significance. PMID:22802784

Are patient specific meshes required for EIT head imaging?

PubMed

Jehl, Markus; Aristovich, Kirill; Faulkner, Mayo; Holder, David

2016-06-01

Head imaging with electrical impedance tomography (EIT) is usually done with time-differential measurements, to reduce time-invariant modelling errors. Previous research suggested that more accurate head models improved image quality, but no thorough analysis has been done on the required accuracy. We propose a novel pipeline for creation of precise head meshes from magnetic resonance imaging and computed tomography scans, which was applied to four different heads. Voltages were simulated on all four heads for perturbations of different magnitude, haemorrhage and ischaemia, in five different positions and for three levels of instrumentation noise. Statistical analysis showed that reconstructions on the correct mesh were on average 25% better than on the other meshes. However, the stroke detection rates were not improved. We conclude that a generic head mesh is sufficient for monitoring patients for secondary strokes following head trauma.

Habitat mosaics and path analysis can improve biological conservation of aquatic biodiversity in ecosystems with low-head dams

USGS Publications Warehouse

Hitchman, Sean M.; Mather, Martha E.; Smith, Joseph M.; Fencl, Jane S.

2018-01-01

Conserving native biodiversity depends on restoring functional habitats in the face of human-induced disturbances. Low-head dams are a ubiquitous human impact that degrades aquatic ecosystems worldwide. To improve our understanding of how low-head dams impact habitat and associated biodiversity, our research examined complex interactions among three spheres of the total environment. i.e., how low-head dams (anthroposphere) affect aquatic habitat (hydrosphere), and native biodiversity (biosphere) in streams and rivers. Creation of lake-like habitats upstream of low-head dams is a well-documented major impact of dams. Alterations downstream of low head dams also have important consequences, but these downstream dam effects are more challenging to detect. In a multidisciplinary field study at five dammed and five undammed sites within the Neosho River basin, KS, we tested hypotheses about two types of habitat sampling (transect and mosaic) and two types of statistical analyses (analysis of covariance and path analysis). We used fish as our example of biodiversity alteration. Our research provided three insights that can aid environmental professionals who seek to conserve and restore fish biodiversity in aquatic ecosystems threatened by human modifications. First, a mosaic approach identified habitat alterations below low-head dams (e.g. increased proportion of riffles) that were not detected using the more commonly-used transect sampling approach. Second, the habitat mosaic approach illustrated how low-head dams reduced natural variation in stream habitat. Third, path analysis, a statistical approach that tests indirect effects, showed how dams, habitat, and fish biodiversity interact. Specifically, path analysis revealed that low-head dams increased the proportion of riffle habitat below dams, and, as a result, indirectly increased fish species richness. Furthermore, the pool habitat that was created above low-head dams dramatically decreased fish species richness. As we show here, mosaic habitat sampling and path analysis can help conservation practitioners improve science-based management plans for disturbed aquatic systems worldwide.

Habitat mosaics and path analysis can improve biological conservation of aquatic biodiversity in ecosystems with low-head dams.

PubMed

Hitchman, Sean M; Mather, Martha E; Smith, Joseph M; Fencl, Jane S

2018-04-01

Conserving native biodiversity depends on restoring functional habitats in the face of human-induced disturbances. Low-head dams are a ubiquitous human impact that degrades aquatic ecosystems worldwide. To improve our understanding of how low-head dams impact habitat and associated biodiversity, our research examined complex interactions among three spheres of the total environment. i.e., how low-head dams (anthroposphere) affect aquatic habitat (hydrosphere), and native biodiversity (biosphere) in streams and rivers. Creation of lake-like habitats upstream of low-head dams is a well-documented major impact of dams. Alterations downstream of low head dams also have important consequences, but these downstream dam effects are more challenging to detect. In a multidisciplinary field study at five dammed and five undammed sites within the Neosho River basin, KS, we tested hypotheses about two types of habitat sampling (transect and mosaic) and two types of statistical analyses (analysis of covariance and path analysis). We used fish as our example of biodiversity alteration. Our research provided three insights that can aid environmental professionals who seek to conserve and restore fish biodiversity in aquatic ecosystems threatened by human modifications. First, a mosaic approach identified habitat alterations below low-head dams (e.g. increased proportion of riffles) that were not detected using the more commonly-used transect sampling approach. Second, the habitat mosaic approach illustrated how low-head dams reduced natural variation in stream habitat. Third, path analysis, a statistical approach that tests indirect effects, showed how dams, habitat, and fish biodiversity interact. Specifically, path analysis revealed that low-head dams increased the proportion of riffle habitat below dams, and, as a result, indirectly increased fish species richness. Furthermore, the pool habitat that was created above low-head dams dramatically decreased fish species richness. As we show here, mosaic habitat sampling and path analysis can help conservation practitioners improve science-based management plans for disturbed aquatic systems worldwide. Copyright © 2017 Elsevier B.V. All rights reserved.

SpaceX CRS-14 What's On Board Science Briefing

NASA Image and Video Library

2018-04-01

During the SpaceX CRS-14 "What's On Board?" Science Briefing inside the Kennedy Space Center Press Site Auditorium, members of the media learned about the research headed to the International Space Station aboard the Dragon spacecraft. The briefing focused on several science projects including the Metabolic Tracking experiment; Atmosphere-Space Interactions Monitor (ASIM); Multi-purpose Variable-g Platform (MVP), and Veggie PONDS Validation. The Dragon spacecraft is scheduled to be launched from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida atop a SpaceX Falcon 9 rocket on the company's 14th Commercial Resupply Services mission to the space station.

Lessons Learned from the Space Shuttle Engine Hydrogen Flow Control Valve Poppet Breakage

NASA Technical Reports Server (NTRS)

Martinez, Hugo E.; Damico, Stephen; Brewer, John

2011-01-01

The Main Propulsion System (MPS) uses three Flow Control Valves (FCV) to modulate the flow of pressurant hydrogen gas from the Space Shuttle Main Engines (SSME) to the hydrogen External Tank (ET). This maintains pressure in the ullage volume as the liquid level drops, preserving ET structural integrity and assuring the engines receive a sufficient amount of head pressure. On Space Transportation System (STS)-126 (2009), with only a handful of International Space Station (ISS) assembly flights from the end of the Shuttle program, a portion of a single FCV?s poppet head broke off at about a minute and a half after liftoff. The risk of the poppet head failure is that the increased flow area through the FCV could result in excessive gaseous hydrogen flow back to the external tank, which could result in overboard venting of hydrogen ullage pressure. If the hydrogen venting were to occur in first stage (i.e., lower atmosphere), a flammability hazard exists that could lead to catastrophic loss of crew and vehicle. Other failure risks included particle impact damage to MPS downstream hardware. Although the FCV design had been plagued by contamination-related sluggish valve response problems prior to a redesign at STS-80 (1996), contamination was ruled out as the cause of the STS-126 failure. Employing a combination of enhanced hardware inspection and a better understanding of the consequences of a poppet failure, safe flight rationale for subsequent flights (STS-119 and later) was achieved. This paper deals with the technical lessons learned during the investigation and mitigation of this problem at a time when assembly flights were each in the critical path to Space Station success.

Gravity of Living Systems: May the Force Be With You

NASA Technical Reports Server (NTRS)

Hargens, Alan R.; Holton, Emily M. (Technical Monitor)

1998-01-01

Gravity, the force which shapes the architecture of organisms from single cells to dinosaurs, has been the most constant environmental factor during the evolution of species on Earth. With long-duration space flight, an understanding of how gravity affects living systems gains greater urgency in order to maintain the health and performance of crews who will explore the solar system. For example, the cardiovascular and musculoskeletal systems are normally exposed to gravitational gradients of blood pressure and weight on Earth. Such gradients increase blood pressure and tissue weight in dependent tissues of the body. Thus, from a physiologic standpoint, these systems are greatly affected by altered gravity. Exposure to actual and simulated microgravity causes blood and tissue fluid to shift from the legs to the head. Studies of humans in space have documented facial edema, space adaptation syndrome, decreased plasma volume, muscle atrophy, and loss of bone strength. Return of astronauts to Earth is accompanied by orthostatic intolerance, decreased neuromuscular coordination, and reduced exercise capacity. These factors decrease performance during descent from orbit and increase risk during emergency egress from the space craft. Models of simulated microgravity include 60 head-down tilt, immersion, and prolonged horizontal bedrest. Head-down tilt and dry immersion are the most accepted models and studies using these models of up to one year have been performed in Russia. Sensitive animal models which offer clear insights into the role of gravity on structure and function include the developing giraffe and snakes from various habitats. Finally, possible countermeasures to speed readaptation of astronauts to gravity after prolonged space flight include exercise, lower body negative pressure, and centrifugation.

Severity mapping of the proximal femur: a new method for assessing hip osteoarthritis with computed tomography.

PubMed

Turmezei, T D; Lomas, D J; Hopper, M A; Poole, K E S

2014-10-01

Plain radiography has been the mainstay of imaging assessment in osteoarthritis for over 50 years, but it does have limitations. Here we present the methodology and results of a new technique for identifying, grading, and mapping the severity and spatial distribution of osteoarthritic disease features at the hip in 3D with clinical computed tomography (CT). CT imaging of 456 hips from 230 adult female volunteers (mean age 66 ± 17 years) was reviewed using 3D multiplanar reformatting to identify bone-related radiological features of osteoarthritis, namely osteophytes, subchondral cysts and joint space narrowing. Scoresheets dividing up the femoral head, head-neck region and the joint space were used to register the location and severity of each feature (scored from 0 to 3). Novel 3D cumulative feature severity maps were then created to display where the most severe disease features from each individual were anatomically located across the cohort. Feature severity maps showed a propensity for osteophytes at the inferoposterior and superolateral femoral head-neck junction. Subchondral cysts were a less common and less localised phenomenon. Joint space narrowing <1.5 mm was recorded in at least one sector of 83% of hips, but most frequently in the posterolateral joint space. This is the first description of hip osteoarthritis using unenhanced clinical CT in which we describe the co-localisation of posterior osteophytes and joint space narrowing for the first time. We believe this technique can perform several important roles in future osteoarthritis research, including phenotyping and sensitive disease assessment in 3D. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Unshrouded Centrifugal Turbopump Impeller Design Methodology

NASA Technical Reports Server (NTRS)

Prueger, George H.; Williams, Morgan; Chen, Wei-Chung; Paris, John; Williams, Robert; Stewart, Eric

2001-01-01

Turbopump weight continues to be a dominant parameter in the trade space for reduction of engine weight. Space Shuttle Main Engine weight distribution indicates that the turbomachinery make up approximately 30% of the total engine weight. Weight reduction can be achieved through the reduction of envelope of the turbopump. Reduction in envelope relates to an increase in turbopump speed and an increase in impeller head coefficient. Speed can be increased until suction performance limits are achieved on the pump or due to alternate constraints the turbine or bearings limit speed. Once the speed of the turbopump is set the impeller tip speed sets the minimum head coefficient of the machine. To reduce impeller diameter the head coefficient must be increased. A significant limitation with increasing head coefficient is that the slope of the head-flow characteristic is affected and this can limit engine throttling range. Unshrouded impellers offer a design option for increased turbopump speed without increasing the impeller head coefficient. However, there are several issues with regard to using an unshrouded impeller: there is a pump performance penalty due to the front open face recirculation flow, there is a potential pump axial thrust problem from the unbalanced front open face and the back shroud face, and since test data is very limited for this configuration, there is uncertainty in the magnitude and phase of the rotordynamic forces due to the front impeller passage. The purpose of the paper is to discuss the design of an unshrouded impeller and to examine the hydrodynamic performance, axial thrust, and rotordynamic performance. The design methodology will also be discussed. This work will help provide some guidelines for unshrouded impeller design.

Sex Comparisons in Muscle Sympathetic Nerve Activity and Arterial Pressure Oscillations During Progressive Central Hypovolemia

DTIC Science & Technology

2015-01-01

Kenney, and P. Kenny. 1988. Cardiovascular responses to head -up tilt after an endurance exercise program. Aviat. Space Environ. Med. 59:107–112...the failure of compensatory mechanisms to maintain blood pressure, subsequently leading to cardiovascular decompensation and syncope. Several...the distribution of blood away from the upper body ( head and heart) to the abdomen and lower extremities, eliciting controlled, experimentally induced

Environmental Loss Characterization of an Advanced Stirling Convertor (ASC-E2) Insulation Package Using a Mock Heater Head

NASA Technical Reports Server (NTRS)

Schifer, Nicholas A.; Briggs, Maxwell H.

2012-01-01

The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. This generator would use two highefficiency Advanced Stirling Convertors (ASCs), developed by Sunpower Inc. and NASA Glenn Research Center (GRC). As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a specified electrical power output for a given net heat input. While electrical power output can be precisely quantified, thermal power input to the Stirling cycle cannot be directly measured. In an effort to improve net heat input predictions, the Mock Heater Head was developed with the same relative thermal paths as a convertor using a conducting rod to represent the Stirling cycle and tested to provide a direct comparison to numerical and empirical models used to predict convertor net heat input. The Mock Heater Head also served as the pathfinder for a higher fidelity version of validation test hardware, known as the Thermal Standard. This paper describes how the Mock Heater Head was tested and utilized to validate a process for the Thermal Standard.

E55_Inflight_JAXA_Gifu_Prefecture__2018_0529_1112_659069

NASA Image and Video Library

2018-05-30

SPACE STATION CREW MEMBER DISCUSSES LIFE IN SPACE WITH JAPANESE STUDENTS--- Aboard the International Space Station, Expedition 55 Flight Engineer Norishige Kanai of the Japan Aerospace Exploration Agency (JAXA) discussed life and space on the orbital outpost during an in-flight educational event May 29 with students gathered at the Gifu Prefecture Air and Space Museum in Japan. Kanai is in the final week of his six month mission on the complex, headed for a landing in a Russian Soyuz spacecraft June 3 on the south central steppe of Kazakhstan.

Wernher von Braun

NASA Image and Video Library

1968-07-31

Ground breaking ceremony for the Alabama Space Science Center, later renamed the U.S. Space and Rocket Center. Shown in this picture, left to right, are Edward O. Buckbee, Space Center Director; Jack Giles, Alabama State Senator of Huntsville; Dr. Wernher on Braun, Marshall Space Flight Center (MSFC) Director; Martin Darity, head of the Alabama Publicity Bureau (representing Governor Albert Brewer); James Allen, former Lieutenant governor, chairman of the Alabama Space Science Exhibit Commission; Major General Charles Eifler, commanding general of the Army Ordnance Missile Command; and Huntsville Mayor Glenrn Hearn. (Courtesy of Huntsville/Madison County Public Library)

Acoustic analysis of changes in articulation proficiency in patients with advanced head and neck cancer treated with chemoradiotherapy.

PubMed

Jacobi, Irene; van Rossum, Maya A; van der Molen, Lisette; Hilgers, Frans J M; van den Brekel, Michiel W M

2013-12-01

Our aim was to characterize articulation proficiency and differences between tumor sites before and after chemoradiotherapy for advanced head and neck cancer with the help of acoustic measures. Our further goal was to improve objective speech measures and gain insight into muscle functioning before and after treatment. In 34 patients with laryngeal or hypopharyngeal, nasal or nasopharyngeal, or oral or oropharyngeal cancer, we acoustically analyzed nasality, vowel space, precision, and strength of articulation in 12 speech sounds (/a/, /i/, /u/, /p/, /s/, /z/, /1/, /t/, /tj/, /k/, /x/, /r/) before treatment and 10 weeks and 1 year after treatment. Outcomes were compared between assessment points and between tumor sites. Nasality in nonlaryngeal sites was significantly reduced by treatment. Most affected in articulation were the oral or oropharyngeal cancer sites, followed by the nasal or nasopharyngeal sites. One year after treatment, vowel space had not recovered and consonant articulation had weakened. Laryngeal sites were less affected in articulation by tumor or treatment. Analyses of articulatory-acoustic features are a useful instrument for assessing articulation and speech quality objectively. Assessment of a number of sounds representing various articulation manners, places, and tongue shapes revealed patterns of speech deterioration after chemoradiotherapy. The results suggest that patients' speech could benefit from articulation exercises to address changes in muscle coordination and/or sensitivity and to counteract side effects and "underexercise" atrophy.

Chosen postures during specific sitting activities.

PubMed

Kamp, Irene; Kilincsoy, Umit; Vink, Peter

2011-11-01

This research study analysed the interaction between people's postures and activities while in semi-public/leisure situations and during transportation (journey by train). In addition, the use of small electronic devices received particular emphasis. Video recordings in German trains and photographs in Dutch semi-public spaces were analysed using a variation of Branton and Grayson's (An evaluation of train seats by observation of sitting behaviour. Ergonomics, 10 (1), (1967), 35-51) postural targeting forms and photos. The analysis suggests a significant relationship between most activities and the position of the head, trunk and arms during transportation situations. The relationship during public situations is less straightforward. Watching, talking/discussing and reading were the most observed activities for the transportation and leisure situations combined. Surprisingly, differences in head, trunk, arm and leg postures were not significant when using small electronic devices. Important issues not considered in this study include the duration of the activities, the gender and age of observed subjects and the influence of the time of day. These are interesting issues to consider and include for future research. STATEMENT OF RELEVANCE: This study shows what activities people choose to carry out and their related postures when not forced to a specific task (e.g. driving). The results of this study can be used for designing comfortable seating in the transportation industry (car passenger, train, bus and aircraft seats) and semi-public/leisure spaces.

A kinematic model for 3-D head-free gaze-shifts

PubMed Central

Daemi, Mehdi; Crawford, J. Douglas

2015-01-01

Rotations of the line of sight are mainly implemented by coordinated motion of the eyes and head. Here, we propose a model for the kinematics of three-dimensional (3-D) head-unrestrained gaze-shifts. The model was designed to account for major principles in the known behavior, such as gaze accuracy, spatiotemporal coordination of saccades with vestibulo-ocular reflex (VOR), relative eye and head contributions, the non-commutativity of rotations, and Listing's and Fick constraints for the eyes and head, respectively. The internal design of the model was inspired by known and hypothesized elements of gaze control physiology. Inputs included retinocentric location of the visual target and internal representations of initial 3-D eye and head orientation, whereas outputs were 3-D displacements of eye relative to the head and head relative to shoulder. Internal transformations decomposed the 2-D gaze command into 3-D eye and head commands with the use of three coordinated circuits: (1) a saccade generator, (2) a head rotation generator, (3) a VOR predictor. Simulations illustrate that the model can implement: (1) the correct 3-D reference frame transformations to generate accurate gaze shifts (despite variability in other parameters), (2) the experimentally verified constraints on static eye and head orientations during fixation, and (3) the experimentally observed 3-D trajectories of eye and head motion during gaze-shifts. We then use this model to simulate how 2-D eye-head coordination strategies interact with 3-D constraints to influence 3-D orientations of the eye-in-space, and the implications of this for spatial vision. PMID:26113816

KSC-07pd0347

NASA Image and Video Library

2007-02-12

KENNEDY SPACE CENTER, FLA. -- The payload canister on its transporter passes the Vehicle Assembly Building at NASA's Kennedy Space Center, heading for Launch Pad 39A. The canister contains the S3/S4 integrated truss for mission STS-117 to the International Space Station aboard Space Shuttle Atlantis. The Atlantis crew will install the new truss segment, retract a set of solar arrays and unfold a new set on the starboard side of the station. Launch is targeted for March 15. Photo credit: NASA/Kim Shiflett

KSC-07pd0346

NASA Image and Video Library

2007-02-12

KENNEDY SPACE CENTER, FLA. -- The payload canister on its transporter leaves the Canister Rotation Facility at NASA's Kennedy Space Center, heading for Launch Pad 39A. The canister contains the S3/S4 integrated truss for mission STS-117 to the International Space Station aboard Space Shuttle Atlantis. The Atlantis crew will install the new truss segment, retract a set of solar arrays and unfold a new set on the starboard side of the station. Launch is targeted for March 15. Photo credit: NASA/Kim Shiflett

KSC-00pp0060

NASA Image and Video Library

2000-01-14

Participants in the First Florida Space Summit take part in a discussion on the future of space as it relates to the State of Florida. The discussion, held at the Kennedy Space Center Visitor Complex, was moderated by Center Director Roy Bridges. Seated (left to right) are Representative Jim Davis, Secretary of Transportation Tom Barry and Rick Stephens, who represented The Boeing Company. The event also included Senator Bob Graham, Senator Connie Mack, Representative Dave Weldon, 45th Space Wing Commander Brig. Gen. Donald Pettit and heads of aerospace companies

KSC00pp0060

NASA Image and Video Library

2000-01-14

Participants in the First Florida Space Summit take part in a discussion on the future of space as it relates to the State of Florida. The discussion, held at the Kennedy Space Center Visitor Complex, was moderated by Center Director Roy Bridges. Seated (left to right) are Representative Jim Davis, Secretary of Transportation Tom Barry and Rick Stephens, who represented The Boeing Company. The event also included Senator Bob Graham, Senator Connie Mack, Representative Dave Weldon, 45th Space Wing Commander Brig. Gen. Donald Pettit and heads of aerospace companies

KSC00pp0055

NASA Image and Video Library

2000-01-14

During the First Florida Space Summit, held at the Kennedy Space Center Visitor Complex, Florida Gov. Jeb Bush, Senator Bob Graham and F.J. Antonio Vittamil, with the governor's office, take a break. The event, featuring a discussion on the future of space as it relates to the State of Florida and moderated by Center Director Roy Bridges, included other participants such as Rep. Dave Weldon, NASA Administrator Dan Goldin, 45th Space Wing Commander Brig. Gen. Donald Pettit and heads of aerospace companies

KSC-00pp0055

NASA Image and Video Library

2000-01-14

During the First Florida Space Summit, held at the Kennedy Space Center Visitor Complex, Florida Gov. Jeb Bush, Senator Bob Graham and F.J. Antonio Vittamil, with the governor's office, take a break. The event, featuring a discussion on the future of space as it relates to the State of Florida and moderated by Center Director Roy Bridges, included other participants such as Rep. Dave Weldon, NASA Administrator Dan Goldin, 45th Space Wing Commander Brig. Gen. Donald Pettit and heads of aerospace companies

KSC00pp0054

NASA Image and Video Library

2000-01-14

Senator Connie Mack and Senator George Kirkpatrick talk before the Florida Space Summit being held today at the Kennedy Space Center Visitor Complex. The event, featuring a discussion on the future of space as it relates to the State of Florida and moderated by Center Director Roy Bridges, included participants such as Senator Bob Graham, Rep. Dave Weldon, members of Florida's State government including Gov. Jeb Bush, NASA Administrator Dan Goldin, 45th Space Wing Commander Brig. Gen. Donald Pettit and heads of aerospace companies

KSC-00pp0054

NASA Image and Video Library

2000-01-14

Senator Connie Mack and Senator George Kirkpatrick talk before the Florida Space Summit being held today at the Kennedy Space Center Visitor Complex. The event, featuring a discussion on the future of space as it relates to the State of Florida and moderated by Center Director Roy Bridges, included participants such as Senator Bob Graham, Rep. Dave Weldon, members of Florida's State government including Gov. Jeb Bush, NASA Administrator Dan Goldin, 45th Space Wing Commander Brig. Gen. Donald Pettit and heads of aerospace companies

Volumetric analysis of cerebrospinal fluid and brain parenchyma in a patient with hydranencephaly and macrocephaly--case report.

PubMed

Radoš, Milan; Klarica, Marijan; Mučić-Pucić, Branka; Nikić, Ines; Raguž, Marina; Galkowski, Valentina; Mandić, Dora; Orešković, Darko

2014-08-28

The aim of this study was to perform for the first time the intracranial volumetric analysis of cerebrospinal fluid (CSF) and brain parenchyma in the supratentorial and infratentorial space in a 30-year-old female patient with hydranencephaly and macrocephaly. A head scan performed using a 3T magnetic resonance was followed by manual segmentation of the brain parenchyma and CSF on T2 coronal brain sections. The volume of CSF and brain parenchyma was measured separately for the supratentorial and infratentorial space. The total volume of the intracranial space was 3645.5 cm3. In the supratentorial space, the volume of CSF was 3375.2 cm3 and the volume of brain parenchyma was 80.3 cm3. In the infratentorial space, the volume of CSF was 101.3 cm3 and the volume of the brain parenchyma was 88.7 cm3. In the supratentorial space, there was severe malacia of almost all brain parenchyma with no visible remnants of the choroid plexuses. Infratentorial structures of the brainstem and cerebellum were hypoplastic but completely developed. Since our patient had no choroid plexuses in the supratentorial space and no obstruction between dural sinuses and CSF, development of hydrocephalus and macrocephaly cannot be explained by the classic hypothesis of CSF physiology with secretion, unidirectional circulation, and absorption as its basic postulates. However, the origin and turnover of the enormous amount of intracranial CSF volume, at least 10-fold larger than normal, and the mechanisms of macroencephaly development could be elucidated by the new hypothesis of CSF physiology recently published by our research team.

Results from the Joint US/Russian Sensory-Motor Investigations

NASA Technical Reports Server (NTRS)

1997-01-01

In this session, Session FA3, the discussion focuses on the following topics: The Effect of Long Duration Space Flight on the Acquisition of Predictable Targets in Three Dimensional Space; Effects of Microgravity on Spinal Reflex Mechanisms; Three Dimensional Head Movement Control During Locomotion After Long-Duration Space Flight; Human Body Shock Wave Transmission Properties After Long Duration Space Flight; Adaptation of Neuromuscular Activation Patterns During Locomotion After Long Duration Space Flight; Balance Control Deficits Following Long-Duration Space Flight; Influence of Weightlessness on Postural Muscular Activity Coordination; and The Use of Inflight Foot Pressure as a Countermeasure to Neuromuscular Degradation.

Access to credit: beginning a new phase.

PubMed

1995-01-01

This article briefly describes an INSTRAW study of an income generation program in the Dominican Republic. The women in development program is operated by the Association for the Development of Micro-Enterprises in the Dominican Republic. The evaluation aims to quantify the results for men and women borrowers in terms of income, family health and nutrition, business reinvestment, job creation, and other measures. The aim is to compare findings between female household heads and non-heads. Findings support other empirical results showing increased sales and income after development. Women invested some of their additional income in their families' health, nutrition, and education. Women also hired other women and tended to employ more unpaid family members. 12% of employees were aged 7-14 years. The use of local community members, who were recent college graduates, as field officers was found to be an effective management tool. The young loan officers were successful in identifying potential clients and in creating accessible opportunities for advice and service. Loan officers increased the number of borrowers, and the program had low rates of nonpayment of loans. Comparisons between female heads and non-heads indicated different reasons for involvement in the program. Non-heads with other income providers reported personal reasons such as self realization and more money. Heads desired financial stability for the family and sometimes satisfaction of survival needs. Female heads tended to reinvest and expand their income-generating capacities. Women tended to increase their working space. This usually meant home space, since many women conducted their business at home. One obstacle was identified which limited income enhancement. For 30% of interviewed women a limit was set on available credit. Credit could only yield income equal to the minimum wage. This pilot study was limited to 400 persons from Santo Domingo. A further impact study is planned which would identify program strengths and weaknesses. Future plans for financial institutions and lending practices would be based on research findings.

14 CFR 1230.123 - Early termination of research support: Evaluation of applications and proposals.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false Early termination of research support... AERONAUTICS AND SPACE ADMINISTRATION PROTECTION OF HUMAN SUBJECTS § 1230.123 Early termination of research... applicable program requirements, when the department or agency head finds an institution has materially...

New Resupply Mission Launches to Space Station on This Week @NASA – June 29, 2018

NASA Image and Video Library

2018-06-29

Almost three tons of supplies and science experiments are headed to the International Space Station, and – Webb Telescope is now targeting March of 2021 as a new launch date … a few of the stories to tell you about – This Week at NASA!

49 CFR 179.400-3 - Type.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.400-3 Type. (a) A tank... (IBR, see § 171.7 of this subchapter); (2) Have the annular space evacuated after filling the annular space with an approved insulating material; (3) Have the inner tank heads designed concave to pressure...

Oculomotor function during space flight and susceptibility to space motion sickness

NASA Technical Reports Server (NTRS)

Thornton, William E.; Uri, John J.

1991-01-01

Horizontal vestibulo-ocular reflex (VOR) and saccadic eye movements (SEM) were studied in 18 subjects before and during five Space Shuttle missions to evaluate the effects of weightlessness and correlations between results and susceptibility to and actual presence of space motion sickness (SMS). Active sinusoidal head oscillation was the stimulus for VOR tests with vision (VVOR), with eyes shaded (VOR-ES), and VOR suppression (VOR-S). Eye movements were recorded by electrooculography and head position by a potentiometer. No pathological nystagmus or other abnormal eye movements were seen. No significant in-flight changes were seen in the gain, phase shift or waveform of VVOR, VOR-ES or VOR-S. Statistically significant increases in saccadic latency and decreases in saccadic velocity were seen, with no change in saccadic accuracy. Preflight differences between SMS susceptible and nonsusceptible subjects were noted only in VOR-S, with less complete suppression in susceptible subjects, a finding also seen in flight. During flight, VVOR gain was significantly increased in three nonaffected subjects. Saccades of SMS-affected subjects showed increased latency and velocity and decreased accuracy compared to saccades of unaffected subjects.

Physiological and behavioral effects of tilt-induced body fluid shifts

NASA Technical Reports Server (NTRS)

Parker, D. E.; Tjernstrom, O.; Ivarsson, A.; Gulledge, W. L.; Poston, R. L.

1983-01-01

This paper addresses the 'fluid shift theory' of space motion sickness. The primary purpose of the research was the development of procedures to assess individual differences in response to rostral body fluid shifts on earth. Experiment I examined inner ear fluid pressure changes during head-down tilt in intact human beings. Tilt produced reliable changes. Differences among subjects and between ears within the same subject were observed. Experiment II examined auditory threshold changes during tilt. Tilt elicited increased auditory thresholds, suggesting that sensory depression may result from increased inner ear fluid pressure. Additional observations on rotation magnitude estimation during head-down tilt, which indicate that rostral fluid shifts may depress semicircular canal activity, are briefly described. The results of this research suggest that the inner ear pressure and auditory threshold shift procedures could be used to assess individual differences among astronauts prior to space flight. Results from the terrestrial observations could be related to reported incidence/severity of motion sickness in space and used to evaluate the fluid shift theory of space motion sickness.

Laser tracker orientation in confined space using on-board targets

NASA Astrophysics Data System (ADS)

Gao, Yang; Kyle, Stephen; Lin, Jiarui; Yang, Linghui; Ren, Yu; Zhu, Jigui

2016-08-01

This paper presents a novel orientation method for two laser trackers using on-board targets attached to the tracker head and rotating with it. The technique extends an existing method developed for theodolite intersection systems which are now rarely used. This method requires only a very narrow space along the baseline between the instrument heads, in order to establish the orientation relationship. This has potential application in environments where space is restricted. The orientation parameters can be calculated by means of two-face reciprocal measurements to the on-board targets, and measurements to a common point close to the baseline. An accurate model is then applied which can be solved through nonlinear optimization. Experimental comparison has been made with the conventional orientation method, which is based on measurements to common intersection points located off the baseline. This requires more space and the comparison has demonstrated the feasibility of the more compact technique presented here. Physical setup and testing suggest that the method is practical. Uncertainties estimated by simulation indicate good performance in terms of measurement quality.

Effect of 1% Inspired CO2 During Head-Down Tilt on Ocular Structures, Cerebral Blood Flow, and Visual Acuity in Healthy Human Subjects

NASA Technical Reports Server (NTRS)

Laurie, S. S.; Hu, X.; Lee, S. M. C.; Martin, D. S.; Phillips, T. R.; Ploutz-Snyder, R.; Smith, S. M.; Stenger, M. B.; Taibbi, G.; Zwart, S. R.;

SpaceX CRS-13 What's on Board Science Briefing

NASA Image and Video Library

2017-12-11

During the SpaceX CRS-13 "What's On Board?" Science Briefing inside the Kennedy Space Center Press Site Auditorium, members of social media learned about the science headed to the International Space Station aboard the Dragon spacecraft. The briefing focused on several research projects including Biorasis Glucose Biosensor; Launchpad Medical; Space Debris Sensor; Total & Spectral solar Irradiance Sensor (TSIS); Fiber Optic Payload (Made in Space); Rodent Research 6; and Plant Gravity Perception. The Dragon spacecraft is scheduled to be launched from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida atop a SpaceX Falcon 9 rocket on the company's 13th Commercial Resupply Services mission to the space station.

Determination of space use by laying hens using kinematic analysis.

PubMed

Mench, Joy A; Blatchford, Richard A

2014-04-01

Two states in the United States now have legislation requiring that laying hens be provided with sufficient space to perform particular behaviors. To provide a framework for translating these performance standards into a space requirement, kinematic analysis was used to measure the amount of space needed for White Leghorn hens to stand, turn around 180°, lie down, and wing flap. Hyline W-36 hens (n = 9) were marked on the tops of their heads and the tips of both wings and 3 toes with black livestock marker. Each hen was then placed in a floor pen (91.4 × 91.4 cm) and filmed using 2 high-speed cameras. The resulting images were processed using a software program that generated 3-dimensional space use for each behavior. Because none of the hens lay down in the test pen, the 2-dimensional space required for lying was determined by superimposing a grid over videos of the hens lying down in their home cages. On average, hens required a mean area of 563 (± 8) cm(2) to stand, 1,316 (± 23) cm(2) to turn around, 318 (± 6) cm(2) to lie down, and 1,693 (± 136) cm(2) to wing flap. The mean heights used were 34.8 (± 1.3) cm for standing, 38.6 (± 2.3) cm for turning, and 49.5 (± 1.8) cm for wing flapping. However, space requirements for hens housed in multiple-hen groups in cage or noncage systems cannot be based simply on information about the space required for local movement by a single hen. It must also incorporate consideration of the tendency of hens in a flock to synchronize their behaviors. In addition, it must include not just local movement space but also the space that hens may need to use for longer-distance movements to access resources such as food, water, perches, and nest boxes.

Miniature Pulse Tube Cooler

NASA Astrophysics Data System (ADS)

Tward, E.; Nguyen, T.; Godden, J.; Toma, G.

2004-06-01

A high capacity miniature pulse tube cooler for space that is scaled from the High Efficiency Cryocooler (HEC) is being developed. The low mass (1.5 kg) integral pulse tube cryocooler can provide large cooling power over a wide temperature range (e.g., 5 W at 95 K). The cooler is designed to be compatible with the existing HEC flight electronics. A small back-to-back flexure compressor drives a pulse tube cold head which is integrated with the compressor. The cooler has been tested with both linear and coaxial cold heads. A description of the cooler and its performance in both linear and coaxial cold head versions is presented.

Behavioral and Psychological Issues in Long Duration Head-down Bed Rest

NASA Technical Reports Server (NTRS)

Seaton, Kimberly A.; Bowie, Kendra; Sipes, Walter A.

2008-01-01

Behavioral health services, similar to those offered to the U.S. astronauts who complete six-month missions on board the International Space Station, were provided to 13 long-duration head-down bed rest participants. Issues in psychological screening, selection, and support are discussed as they relate to other isolated and confined environments. Psychological services offered to participants are described, and challenges in subject selection and retention are discussed. Psychological support and training provided to both subjects and study personnel have successfully improved the well-being of study participants. Behavioral health services are indispensable to long-duration head-down tilt bed rest studies.

Dynamic modulation of ocular orientation during visually guided saccades and smooth-pursuit eye movements

NASA Technical Reports Server (NTRS)

Hess, Bernhard J M.; Angelaki, Dora E.

2003-01-01

Rotational disturbances of the head about an off-vertical yaw axis induce a complex vestibuloocular reflex pattern that reflects the brain's estimate of head angular velocity as well as its estimate of instantaneous head orientation (at a reduced scale) in space coordinates. We show that semicircular canal and otolith inputs modulate torsional and, to a certain extent, also vertical ocular orientation of visually guided saccades and smooth-pursuit eye movements in a similar manner as during off-vertical axis rotations in complete darkness. It is suggested that this graviceptive control of eye orientation facilitates rapid visual spatial orientation during motion.

Influence of vision on head stabilization strategies in older adults during walking.

PubMed

Cromwell, Ronita L; Newton, Roberta A; Forrest, Gail

2002-07-01

Maintaining balance during dynamic activities is essential for preventing falls in older adults. Head stabilization contributes to dynamic balance, especially during the functional task of walking. Head stability and the role of vision in this process have not been studied during walking in older adults. Seventeen older adults (76.2 +/- 6.9 years) and 20 young adults (26.0 +/- 3.4 years) walked with their eyes open (EO), with their eyes closed (EC), and with fixed gaze (FG). Participants performed three trials of each condition. Sagittal plane head and trunk angular velocities in space were obtained using an infrared camera system with passive reflective markers. Frequency analyses of head-on-trunk with respect to trunk gains and phases were examined for head-trunk movement strategies used for head stability. Average walking velocity, cadence, and peak head velocity were calculated for each condition. Differences between age groups demonstrated that older adults decreased walking velocity in EO (p =.022). FG (p = .021), and EC (p = .022). and decreased cadence during EC (p = .007). Peak head velocity also decreased across conditions (p < .0001) for older adults. Movement patterns demonstrated increased head stability during EO. diminished head stability with EC, and improved head stability with FG as older adult patterns resembled those of young adults. Increased stability of the lower extremity outcome measures for older adults was indicated by reductions in walking velocity and cadence. Concomitant increases in head stability were related to visual tasks. Increased stability may serve as a protective mechanism to prevent falls. Further, vision facilitates the head stabilization process for older adults to compensate for age-related decrements in other sensory systems subserving dynamic balance.

Face-infringement space: the frame of reference of the ventral intraparietal area.

PubMed

McCollum, Gin; Klam, François; Graf, Werner

2012-07-01

Experimental studies have shown that responses of ventral intraparietal area (VIP) neurons specialize in head movements and the environment near the head. VIP neurons respond to visual, auditory, and tactile stimuli, smooth pursuit eye movements, and passive and active movements of the head. This study demonstrates mathematical structure on a higher organizational level created within VIP by the integration of a complete set of variables covering face-infringement. Rather than positing dynamics in an a priori defined coordinate system such as those of physical space, we assemble neuronal receptive fields to find out what space of variables VIP neurons together cover. Section 1 presents a view of neurons as multidimensional mathematical objects. Each VIP neuron occupies or is responsive to a region in a sensorimotor phase space, thus unifying variables relevant to the disparate sensory modalities and movements. Convergence on one neuron joins variables functionally, as space and time are joined in relativistic physics to form a unified spacetime. The space of position and motion together forms a neuronal phase space, bridging neurophysiology and the physics of face-infringement. After a brief review of the experimental literature, the neuronal phase space natural to VIP is sequentially characterized, based on experimental data. Responses of neurons indicate variables that may serve as axes of neural reference frames, and neuronal responses have been so used in this study. The space of sensory and movement variables covered by VIP receptive fields joins visual and auditory space to body-bound sensory modalities: somatosensation and the inertial senses. This joining of allocentric and egocentric modalities is in keeping with the known relationship of the parietal lobe to the sense of self in space and to hemineglect, in both humans and monkeys. Following this inductive step, variables are formalized in terms of the mathematics of graph theory to deduce which combinations are complete as a multidimensional neural structure that provides the organism with a complete set of options regarding objects impacting the face, such as acceptance, pursuit, and avoidance. We consider four basic variable types: position and motion of the face and of an external object. Formalizing the four types of variables allows us to generalize to any sensory system and to determine the necessary and sufficient conditions for a neural center (for example, a cortical region) to provide a face-infringement space. We demonstrate that VIP includes at least one such face-infringement space.

Heat transfer head for a Stirling cycle machine

NASA Technical Reports Server (NTRS)

Emigh, Stuart G. (Inventor); Noble, Jack E. (Inventor); Lehmann, Gregory A. (Inventor)

1991-01-01

A common heat acceptor is provided between opposed displacers in a Stirling cycle machine. It includes two sets of open channels in separate fluid communications with the expansion spaces of the receptive cyclinders. The channels confine movement of working fluid in separate paths that extend between the expansion space of one cylinder and the compression space of the other. The method for operating the machine involves alternatively directing working fluid from the expansion space of each cylinder in a fluid path leading to the compression space of the other cylinder and from the compression space of each cylinder in a fluid path leading to the expansion space of the other cylinder.

Conservation of water for washing beef heads at harvest.

PubMed

DeOtte, R E; Spivey, K S; Galloway, H O; Lawrence, T E

2010-03-01

The objective of this research was to develop methods to conserve water necessary to cleanse beef heads prior to USDA-FSIS inspection. This was to be accomplished by establishing a baseline for the minimum amount of water necessary to adequately wash a head and application of image analysis to provide an objective measure of head cleaning. Twenty-one beef heads were manually washed during the harvest process. An average 18.75 L (2.49 SD) and a maximum of 23.88 L were required to cleanse the heads to USDA-FSIS standards. Digital images were captured before and after manual washing then evaluated for percentage red saturation using commercially available image analysis software. A decaying exponential curve extracted from these data indicated that as wash water increased beyond 20 L the impact on red saturation decreased. At 4 sigma from the mean of 18.75 L, red saturation is 16.0 percent, at which logistic regression analysis indicates 99.994 percent of heads would be accepted for inspection, or less than 1 head in 15,000 would be rejected. Reducing to 3 sigma would increase red saturation to 27.6 percent, for which 99.730 percent of heads likely would be accepted (less than 1 in 370 would be rejected). Copyright 2009 Elsevier Ltd. All rights reserved.

Advanced Stirling Convertor Heater Head Durability and Reliability Quantification

NASA Technical Reports Server (NTRS)

Krause, David L.; Shah, Ashwin R.; Korovaichuk, Igor; Kalluri, Sreeramesh

2008-01-01

The National Aeronautics and Space Administration (NASA) has identified the high efficiency Advanced Stirling Radioisotope Generator (ASRG) as a candidate power source for long duration Science missions, such as lunar applications, Mars rovers, and deep space missions, that require reliable design lifetimes of up to 17 years. Resistance to creep deformation of the MarM-247 heater head (HH), a structurally critical component of the ASRG Advanced Stirling Convertor (ASC), under high temperatures (up to 850 C) is a key design driver for durability. Inherent uncertainties in the creep behavior of the thin-walled HH and the variations in the wall thickness, control temperature, and working gas pressure need to be accounted for in the life and reliability prediction. Due to the availability of very limited test data, assuring life and reliability of the HH is a challenging task. The NASA Glenn Research Center (GRC) has adopted an integrated approach combining available uniaxial MarM-247 material behavior testing, HH benchmark testing and advanced analysis in order to demonstrate the integrity, life and reliability of the HH under expected mission conditions. The proposed paper describes analytical aspects of the deterministic and probabilistic approaches and results. The deterministic approach involves development of the creep constitutive model for the MarM-247 (akin to the Oak Ridge National Laboratory master curve model used previously for Inconel 718 (Special Metals Corporation)) and nonlinear finite element analysis to predict the mean life. The probabilistic approach includes evaluation of the effect of design variable uncertainties in material creep behavior, geometry and operating conditions on life and reliability for the expected life. The sensitivity of the uncertainties in the design variables on the HH reliability is also quantified, and guidelines to improve reliability are discussed.

Detecting large-scale networks in the human brain using high-density electroencephalography.

PubMed

Liu, Quanying; Farahibozorg, Seyedehrezvan; Porcaro, Camillo; Wenderoth, Nicole; Mantini, Dante

2017-09-01

High-density electroencephalography (hdEEG) is an emerging brain imaging technique that can be used to investigate fast dynamics of electrical activity in the healthy and the diseased human brain. Its applications are however currently limited by a number of methodological issues, among which the difficulty in obtaining accurate source localizations. In particular, these issues have so far prevented EEG studies from reporting brain networks similar to those previously detected by functional magnetic resonance imaging (fMRI). Here, we report for the first time a robust detection of brain networks from resting state (256-channel) hdEEG recordings. Specifically, we obtained 14 networks previously described in fMRI studies by means of realistic 12-layer head models and exact low-resolution brain electromagnetic tomography (eLORETA) source localization, together with independent component analysis (ICA) for functional connectivity analysis. Our analyses revealed three important methodological aspects. First, brain network reconstruction can be improved by performing source localization using the gray matter as source space, instead of the whole brain. Second, conducting EEG connectivity analyses in individual space rather than on concatenated datasets may be preferable, as it permits to incorporate realistic information on head modeling and electrode positioning. Third, the use of a wide frequency band leads to an unbiased and generally accurate reconstruction of several network maps, whereas filtering data in a narrow frequency band may enhance the detection of specific networks and penalize that of others. We hope that our methodological work will contribute to rise of hdEEG as a powerful tool for brain research. Hum Brain Mapp 38:4631-4643, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Synchronization Tomography: Modeling and Exploring Complex Brain Dynamics

NASA Astrophysics Data System (ADS)

Fieseler, Thomas

2002-03-01

Phase synchronization (PS) plays an important role both under physiological and pathological conditions. With standard averaging techniques of MEG data, it is difficult to reliably detect cortico-cortical and cortico-muscular PS processes that are not time-locked to an external stimulus. For this reason, novel synchronization analysis techniques were developed and directly applied to MEG signals. Of course, due to the lack of an inverse modeling (i.e. source localization), the spatial resolution of this approach was limited. To detect and localize cerebral PS, we here present the synchronization tomography (ST): For this, we first estimate the cerebral current source density by means of the magnetic field tomography (MFT). We then apply the single-run PS analysis to the current source density in each voxel of the reconstruction space. In this way we study simulated PS, voxel by voxel in order to determine the spatio-temporal resolution of the ST. To this end different generators of ongoing rhythmic cerebral activity are simulated by current dipoles at different locations and directions, which are modeled by slightly detuned chaotic oscillators. MEG signals for these generators are simulated for a spherical head model and a whole-head MEG system. MFT current density solutions are calculated from these simulated signals within a hemispherical source space. We compare the spatial resolution of the ST with that of the MFT. Our results show that adjacent sources which are indistinguishable for the MFT, can nevertheless be separated with the ST, provided they are not strongly phase synchronized. This clearly demonstrates the potential of combining spatial information (i.e. source localization) with temporal information for the anatomical localization of phase synchronization in the human brain.

Reconstruction of human brain spontaneous activity based on frequency-pattern analysis of magnetoencephalography data

PubMed Central

Llinás, Rodolfo R.; Ustinin, Mikhail N.; Rykunov, Stanislav D.; Boyko, Anna I.; Sychev, Vyacheslav V.; Walton, Kerry D.; Rabello, Guilherme M.; Garcia, John

2015-01-01

A new method for the analysis and localization of brain activity has been developed, based on multichannel magnetic field recordings, over minutes, superimposed on the MRI of the individual. Here, a high resolution Fourier Transform is obtained over the entire recording period, leading to a detailed multi-frequency spectrum. Further analysis implements a total decomposition of the frequency components into functionally invariant entities, each having an invariant field pattern localizable in recording space. The method, addressed as functional tomography, makes it possible to find the distribution of magnetic field sources in space. Here, the method is applied to the analysis of simulated data, to oscillating signals activating a physical current dipoles phantom, and to recordings of spontaneous brain activity in 10 healthy adults. In the analysis of simulated data, 61 dipoles are localized with 0.7 mm precision. Concerning the physical phantom the method is able to localize three simultaneously activated current dipoles with 1 mm precision. Spatial resolution 3 mm was attained when localizing spontaneous alpha rhythm activity in 10 healthy adults, where the alpha peak was specified for each subject individually. Co-registration of the functional tomograms with each subject's head MRI localized alpha range activity to the occipital and/or posterior parietal brain region. This is the first application of this new functional tomography to human brain activity. The method successfully provides an overall view of brain electrical activity, a detailed spectral description and, combined with MRI, the localization of sources in anatomical brain space. PMID:26528119

The Direction of Fluid Dynamics for Liquid Propulsion at NASA Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Griffin, Lisa W.

2012-01-01

Marshall Space Flight Center (MSFC) is the National Aeronautics and Space Administration (NASA)-designated center for the development of space launch systems. MSFC is particularly known for propulsion system development. Many engineering skills and technical disciplines are needed to accomplish this mission. This presentation will focus on the work of the Fluid Dynamics Branch (ER42). ER42 resides in the Propulsion Systems Department at MSFC. The branch is responsible for all aspects of the discipline of fluid dynamics applied to propulsion or propulsion-induced loads and environments. This work begins with design trades and parametric studies, and continues through development, risk assessment, anomaly investigation and resolution, and failure investigations. Applications include the propellant delivery system including the main propulsion system (MPS) and turbomachinery; combustion devices for liquid engines and solid rocket motors; coupled systems; and launch environments. An advantage of the branch is that it is neither analysis nor test centric, but discipline centric. Fluid dynamics assessments are made by analysis, from lumped parameter modeling through unsteady computational fluid dynamics (CFD); testing, which can be cold flow or hot fire; or a combination of analysis and testing. Integration of all discipline methods into one branch enables efficient and accurate support to the projects. To accomplish this work, the branch currently employs approximately fifty engineers divided into four teams -- Propellant Delivery CFD, Combustion Driven Flows CFD, Unsteady and Experimental Flows, and Acoustics and Stability. This discussion will highlight some of the work performed in the branch and the direction in which the branch is headed.

The moving minimum audible angle is smaller during self motion than during source motion

PubMed Central

Brimijoin, W. Owen; Akeroyd, Michael A.

2014-01-01

We are rarely perfectly still: our heads rotate in three axes and move in three dimensions, constantly varying the spectral and binaural cues at the ear drums. In spite of this motion, static sound sources in the world are typically perceived as stable objects. This argues that the auditory system—in a manner not unlike the vestibulo-ocular reflex—works to compensate for self motion and stabilize our sensory representation of the world. We tested a prediction arising from this postulate: that self motion should be processed more accurately than source motion. We used an infrared motion tracking system to measure head angle, and real-time interpolation of head related impulse responses to create “head-stabilized” signals that appeared to remain fixed in space as the head turned. After being presented with pairs of simultaneous signals consisting of a man and a woman speaking a snippet of speech, normal and hearing impaired listeners were asked to report whether the female voice was to the left or the right of the male voice. In this way we measured the moving minimum audible angle (MMAA). This measurement was made while listeners were asked to turn their heads back and forth between ± 15° and the signals were stabilized in space. After this “self-motion” condition we measured MMAA in a second “source-motion” condition when listeners remained still and the virtual locations of the signals were moved using the trajectories from the first condition. For both normal and hearing impaired listeners, we found that the MMAA for signals moving relative to the head was ~1–2° smaller when the movement was the result of self motion than when it was the result of source motion, even though the motion with respect to the head was identical. These results as well as the results of past experiments suggest that spatial processing involves an ongoing and highly accurate comparison of spatial acoustic cues with self-motion cues. PMID:25228856

Principle Study of Head Meridian Acupoint Massage to Stress Release via Grey Data Model Analysis.

PubMed

Lee, Ya-Ting

2016-01-01

This paper presents the scientific study of the effectiveness and action principle of head meridian acupoint massage by applying the grey data model analysis approach. First, the head massage procedure for massaging the important head meridian acupuncture points including Taiyang, Fengfu, Tianzhu, Fengqi, and Jianjing is formulated in a standard manner. Second, the status of the autonomic nervous system of each subject is evaluated by using the heart rate variability analyzer before and after the head massage following four weeks. Afterward, the physiological factors of autonomic nerves are quantitatively analyzed by using the grey data modeling theory. The grey data analysis can point out that the status of autonomic nervous system is greatly improved after the massage. The order change of the grey relationship weighting of physiological factors shows the action principle of the sympathetic and parasympathetic nerves when performing head massage. In other words, the grey data model is able to distinguish the detailed interaction of the autonomic nervous system and the head meridian acupoint massage. Thus, the stress relaxing effect of massaging head meridian acupoints is proved, which is lacked in literature. The results can be a reference principle for massage health care in practice.

Principle Study of Head Meridian Acupoint Massage to Stress Release via Grey Data Model Analysis

PubMed Central

Lee, Ya-Ting

2016-01-01

This paper presents the scientific study of the effectiveness and action principle of head meridian acupoint massage by applying the grey data model analysis approach. First, the head massage procedure for massaging the important head meridian acupuncture points including Taiyang, Fengfu, Tianzhu, Fengqi, and Jianjing is formulated in a standard manner. Second, the status of the autonomic nervous system of each subject is evaluated by using the heart rate variability analyzer before and after the head massage following four weeks. Afterward, the physiological factors of autonomic nerves are quantitatively analyzed by using the grey data modeling theory. The grey data analysis can point out that the status of autonomic nervous system is greatly improved after the massage. The order change of the grey relationship weighting of physiological factors shows the action principle of the sympathetic and parasympathetic nerves when performing head massage. In other words, the grey data model is able to distinguish the detailed interaction of the autonomic nervous system and the head meridian acupoint massage. Thus, the stress relaxing effect of massaging head meridian acupoints is proved, which is lacked in literature. The results can be a reference principle for massage health care in practice. PMID:26904144

Portable cutting apparatus

DOEpatents

Gilmore, Richard F.

1986-01-01

A remotely operable, portable cutting apparatus detachably secured to the workpiece by laterally spaced clamp assemblies engageable with the workpiece on opposite sides of the intended line of cut. A reciprocal cutter head is mounted between the clamp assemblies and is provided with a traveling abrasive cutting wire adapted to sever the workpiece normal to the longitudinal axis thereof. Dust and debris are withdrawn from the cutting area by a vacuum force through a nozzle mounted on the cutting head.

Portable cutting apparatus

DOEpatents

Gilmore, R.F.

1984-07-17

A remotely operable, portable cutting apparatus detachably secured to the workpiece by laterally spaced clamp assemblies engagable with the workpiece on opposite sides of the intended line of cut. A reciprocal cutter head is mounted between the clamp assemblies and is provided with a traveling abrasive cutting wire adapted to sever the workpiece normal to the longitudinal axis thereof. Dust and debris are withdrawn from the cutting area by a vacuum force through a nozzle mounted on the cutting head.

Portable cutting apparatus

DOEpatents

Gilmore, Richard F.

1986-04-01

A remotely operable, portable cutting apparatus detachably secured to the workpiece by laterally spaced clamp assemblies engageable with the workpiece on opposite sides of the intended line of cut. A reciprocal cutter head is mounted between the clamp assemblies and is provided with a traveling abrasive cutting wire adapted to sever the workpiece normal to the longitudinal axis thereof. Dust and debris are withdrawn from the cutting area by a vacuum force through a nozzle mounted on the cutting head.

Importance of partitioning membranes of the brain and the influence of the neck in head injury modelling.

PubMed

Kumaresan, S; Radhakrishnan, S

1996-01-01

A head injury model consisting of the skull, the CSF, the brain and its partitioning membranes and the neck region is simulated by considering its near actual geometry. Three-dimensional finite-element analysis is carried out to investigate the influence of the partitioning membranes of the brain and the neck in head injury analysis through free-vibration analysis and transient analysis. In free-vibration analysis, the first five modal frequencies are calculated, and in transient analysis intracranial pressure and maximum shear stress in the brain are determined for a given occipital impact load.

Positional Asphyxia: Death Due to Unusual Head-Down Position in a Narrow Space.

PubMed

Chaudhari, Vinod Ashok; Ghodake, Dattatray G; Kharat, Rajesh D

2016-06-01

Death due to a head-down position with hyperflexion of the neck is a rare event. A person accidentally falling into a narrow space and remaining in an upside-down position with no timely recovery may experience positional or postural asphyxia. It is a critical condition arising out of particular body positions, leading to mechanical obstruction of respiration. The precipitating factors are intoxication due to alcohol, drugs, obesity, psychiatric illnesses, and injuries. A 30-year-old unmarried woman, weighing 82 kg and with a body mass index of 31.24, was found in a narrow space between the bed and the wall in a naked state and in a head-down position with hyperflexion of the neck. The distribution of lividity was consistent with the position of the body at the scene. Blood was oozing from the mouth and nostrils, and signs of asphyxia were present. The toxicological analyses of viscera, blood, and urine were negative for alcohol, drugs, and poisons. Glucose levels in the blood (86 mg/dL) as well as urine and vitreous humor levels (68 mg/dL) were within normal limits. On microscopic examination, there were no findings of coronary atherosclerosis, whereas the brain and lung were edematous. After meticulous examination, we ruled out sexual assault, autoerotic asphyxia, epilepsy, psychiatric illness, diabetes, toxicity, and coronary artery disease. Death was attributed to the accidental fall of the obese individual being stuck in a narrow space, resulting in positional asphyxia. It is imperative to recognize the precipitating or risk factors before labeling positional asphyxia as a cause of death.

Measurement of Pressure Responses in a Physical Model of a Human Head with High Shape Fidelity Based on Ct/mri Data

NASA Astrophysics Data System (ADS)

Miyazaki, Yusuke; Tachiya, Hiroshi; Anata, Kenji; Hojo, Akihiro

This study discusses a head injury mechanism in case of a human head subjected to impact, from results of impact experiments by using a physical model of a human head with high-shape fidelity. The physical model was constructed by using rapid prototyping technology from the three-dimensional CAD data, which obtained from CT/MRI images of a subject's head. As results of the experiments, positive pressure responses occurred at the impacted site, whereas negative pressure responses occurred at opposite the impacted site. Moreover, the absolute maximum value of pressure occurring at the frontal region of the intracranial space of the head model resulted in same or higher than that at the occipital site in each case that the impact force was imposed on frontal or occipital region. This result has not been showed in other study using simple shape physical models. And, the result corresponds with clinical evidences that brain contusion mainly occurs at the frontal part in each impact direction. Thus, physical model with accurate skull shape is needed to clarify the mechanism of brain contusion.

Midwives experiences of removal of a newborn baby in New South Wales, Australia: Being in the 'head' and 'heart' space.

PubMed

Everitt, Louise; Fenwick, Jennifer; Homer, Caroline S E

2015-06-01

A newborn baby is removed from his/her mother into formal care when he/she is considered at risk of serious harm and it is not in the best interests to go home with their parent(s) or carer(s). In New South Wales (NSW), this removal is known as an "assumption of care". This process is challenging for all involved especially when it occurs soon after birth. There is very limited research to inform midwives in this area of practice. To explore the experiences of midwives who had been involved in the assumption of care of a baby soon after birth or in the early postnatal period. A qualitative descriptive approach was used. Ten midwives involved with the assumption of care of a baby were interviewed. A thematic analysis was undertaken. There were two overarching themes. "Being in the head space" represented the activities, tasks and/or processes midwives engaged in when involved in an assumption of care. "Being in the heart space" described the emotional impact on midwives, as well as their perceptions on how women were affected. Midwives described feeling unprepared and unsupported, in both the processes and the impact of assumption of care. They were confronted by this profound emotional work and described experiencing professional grief, similar to that felt when caring for a woman experiencing a stillbirth. In the future, midwives need to be provided with support to ensure that they can effectively care for these women and also manage the emotional impact themselves. Copyright © 2015 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

Leadership in nursing: analysis of the process of choosing the heads.

PubMed

de Moura, Gisela Maria Schebella Souto; de Magalhaes, Ana Maria Müller; Dall'agnol, Clarice Maria; Juchem, Beatriz Cavalcanti; Marona, Daniela dos Santos

2010-01-01

The process of choosing heads can be strategic to achieve desired results in nursing care. This study presents an exploratory and descriptive research that aims to analyze the process of choosing heads for the ward, in the nursing area of a teaching hospital in Porto Alegre. Data was collected from registered nurses, technicians and nursing auxiliaries through a semi-structured interview technique and free choice of words. Three theme categories emerged from content analysis: process of choosing heads, managerial competences of the head-to-be and team articulation. Leadership was the word most frequently associated with the process of choosing heads. The consultation process for the choice of the leader also contributes to the success of the manager, as it makes the team members feel co-responsible for the results achieved and legitimizes the head-to-be in their group.

Mechanisms of head injuries in elite football

PubMed Central

Andersen, T; Arnason, A; Engebretsen, L; Bahr, R

2004-01-01

Objectives: The aim of this study was to describe, using video analysis, the mechanisms of head injuries and of incidents with a high risk of head injury in elite football. Methods: Videotapes and injury information were collected prospectively for 313 of the 409 matches played in the Norwegian (2000 season) and Icelandic (1999 and 2000 season) professional leagues. Video recordings of incidents where a player appeared to be hit in the head and the match was consequently interrupted by the referee were analysed and cross referenced with reports of acute time loss injuries from the team medical staff. Results: The video analysis revealed 192 incidents (18.8 per 1000 player hours). Of the 297 acute injuries reported, 17 (6%) were head injuries, which corresponds to an incidence of 1.7 per 1000 player hours (concussion incidence 0.5 per 1000 player hours). The most common playing action was a heading duel with 112 cases (58%). The body part that hit the injured player's head was the elbow/arm/hand in 79 cases (41%), the head in 62 cases (32%), and the foot in 25 cases (13%). In 67 of the elbow/arm/hand impacts, the upper arm of the player causing the incident was at or above shoulder level, and the arm use was considered to be active in 61 incidents (77%) and intentional in 16 incidents (20%). Conclusions: This study suggests that video analysis provides detailed information about the mechanisms for head injuries in football. The most frequent injury mechanism was elbow to head contact, followed by head to head contact in heading duels. In the majority of the elbow to head incidents, the elbow was used actively at or above shoulder level, and stricter rule enforcement or even changes in the laws of the game concerning elbow use should perhaps be considered, in order to reduce the risk of head injury. PMID:15562161

Free-space-coupled superconducting nanowire single-photon detectors for infrared optical communications.

PubMed

Bellei, Francesco; Cartwright, Alyssa P; McCaughan, Adam N; Dane, Andrew E; Najafi, Faraz; Zhao, Qingyuan; Berggren, Karl K

2016-02-22

This paper describes the construction of a cryostat and an optical system with a free-space coupling efficiency of 56.5% ± 3.4% to a superconducting nanowire single-photon detector (SNSPD) for infrared quantum communication and spectrum analysis. A 1K pot decreases the base temperature to T = 1.7 K from the 2.9 K reached by the cold head cooled by a pulse-tube cryocooler. The minimum spot size coupled to the detector chip was 6.6 ± 0.11 µm starting from a fiber source at wavelength, λ = 1.55 µm. We demonstrated photon counting on a detector with an 8 × 7.3 µm2 area. We measured a dark count rate of 95 ± 3.35 kcps and a system detection efficiency of 1.64% ± 0.13%. We explain the key steps that are required to improve further the coupling efficiency.

Recent Advances in Laplace Transform Analytic Element Method (LT-AEM) Theory and Application to Transient Groundwater Flow

NASA Astrophysics Data System (ADS)

Kuhlman, K. L.; Neuman, S. P.

2006-12-01

Furman and Neuman (2003) proposed a Laplace Transform Analytic Element Method (LT-AEM) for transient groundwater flow. LT-AEM applies the traditionally steady-state AEM to the Laplace transformed groundwater flow equation, and back-transforms the resulting solution to the time domain using a Fourier Series numerical inverse Laplace transform method (de Hoog, et.al., 1982). We have extended the method so it can compute hydraulic head and flow velocity distributions due to any two-dimensional combination and arrangement of point, line, circular and elliptical area sinks and sources, nested circular or elliptical regions having different hydraulic properties, and areas of specified head, flux or initial condition. The strengths of all sinks and sources, and the specified head and flux values, can all vary in both space and time in an independent and arbitrary fashion. Initial conditions may vary from one area element to another. A solution is obtained by matching heads and normal fluxes along the boundary of each element. The effect which each element has on the total flow is expressed in terms of generalized Fourier series which converge rapidly (<20 terms) in most cases. As there are more matching points than unknown Fourier terms, the matching is accomplished in Laplace space using least-squares. The method is illustrated by calculating the resulting transient head and flow velocities due to an arrangement of elements in both finite and infinite domains. The 2D LT-AEM elements already developed and implemented are currently being extended to solve the 3D groundwater flow equation.

Postural control and head stability during natural gaze behaviour in 6- to 12-year-old children.

PubMed

Schärli, A M; van de Langenberg, R; Murer, K; Müller, R M

2013-06-01

We investigated how the influence of natural exploratory gaze behaviour on postural control develops from childhood into adulthood. In a cross-sectional design, we compared four age groups: 6-, 9-, 12-year-olds and young adults. Two experimental trials were performed: quiet stance with a fixed gaze (fixed) and quiet stance with natural exploratory gaze behaviour (exploratory). The latter was elicited by having participants watch an animated short film on a large screen in front of them. 3D head rotations in space and centre of pressure (COP) excursions on the ground plane were measured. Across conditions, both head rotation and COP displacement decreased with increasing age. Head movement was greater in the exploratory condition in all age groups. In all children-but not in adults-COP displacement was markedly greater in the exploratory condition. Bivariate correlations across groups showed highly significant positive correlations between COP displacement in ML direction and head rotation in yaw, roll, and pitch in both conditions. The regularity of COP displacements did not show a clear developmental trend, which indicates that COP dynamics were qualitatively similar across age groups. Together, the results suggest that the contribution of head movement to eye-head saccades decreases with age and that head instability-in part resulting from such gaze-related head movements-is an important limiting factor in children's postural control. The lack of head stabilisation might particularly affect children in everyday activities in which both postural control and visual exploration are required.

STS-66 landing at Edwards Air Force Base

NASA Technical Reports Server (NTRS)

1994-01-01

The main landing gear is on the ground and the nose gear is about to touch down as the Space Shuttle Atlantis heads toward a stop at Edwards Air Force Base in southern California, ending a successful 10 day, 22 hour and 34 minute space mission. Landing occured at 7:34 a.m. (PST), November 14, 1994.

Resource configuration and abundance affect space use of a cooperatively breeding resident bird

Treesearch

Richard A. Stanton; Dylan C. Kesler; Frank R. Thompson III

2014-01-01

Movement and space use of birds is driven by activities associated with acquiring and maintaining access to critical resources. Thus, the spatial configuration of resources within home ranges should influence bird movements, and resource values should be relative to their locations. We radio-tracked 22 Brown-headed Nuthatches (Sitta pusilla) and...

Dissapearance of arachnoid cyst after rupturing into subdural space.

PubMed

Yilmaz, C; Cetinalp, E; Caner, H; Altinors, N

2007-01-01

Arachnoid cysts are developmental anomalies usually diagnosed in childhood. The most important complications of arachnoid cysts are subdural haematomas and hygromas and intracystic haemorrhage. In our case we present a 7-year-old boy whose arachnoid cyst ruptured into the subdural space following a mild head injury and disappeared after draining the subdural haematoma by burr-holes.

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

Rajauria, Sukumar, E-mail: sukumar.rajauria@hgst.com; Canchi, Sripathi V., E-mail: sripathi.canchi@hgst.com; Schreck, Erhard

The kinetic friction and wear at high sliding speeds is investigated using the head-disk interface of hard disk drives, wherein the head and the disk are less than 10 nm apart and move at sliding speeds of 5–10 m/s relative to each other. While the spacing between the sliding surfaces is of the same order of magnitude as various AFM based fundamental studies on friction, the sliding speed is nearly six orders of magnitude larger, allowing a unique set-up for a systematic study of nanoscale wear at high sliding speeds. In a hard disk drive, the physical contact between the head andmore » the disk leads to friction, wear, and degradation of the head overcoat material (typically diamond like carbon). In this work, strain gauge based friction measurements are performed; the friction coefficient as well as the adhering shear strength at the head-disk interface is extracted; and an experimental set-up for studying friction between high speed sliding surfaces is exemplified.« less

Nanoscale wear and kinetic friction between atomically smooth surfaces sliding at high speeds

NASA Astrophysics Data System (ADS)

Rajauria, Sukumar; Canchi, Sripathi V.; Schreck, Erhard; Marchon, Bruno

2015-02-01

The kinetic friction and wear at high sliding speeds is investigated using the head-disk interface of hard disk drives, wherein the head and the disk are less than 10 nm apart and move at sliding speeds of 5-10 m/s relative to each other. While the spacing between the sliding surfaces is of the same order of magnitude as various AFM based fundamental studies on friction, the sliding speed is nearly six orders of magnitude larger, allowing a unique set-up for a systematic study of nanoscale wear at high sliding speeds. In a hard disk drive, the physical contact between the head and the disk leads to friction, wear, and degradation of the head overcoat material (typically diamond like carbon). In this work, strain gauge based friction measurements are performed; the friction coefficient as well as the adhering shear strength at the head-disk interface is extracted; and an experimental set-up for studying friction between high speed sliding surfaces is exemplified.

Spatial cue reliability drives frequency tuning in the barn Owl's midbrain

PubMed Central

Cazettes, Fanny; Fischer, Brian J; Pena, Jose L

2014-01-01

The robust representation of the environment from unreliable sensory cues is vital for the efficient function of the brain. However, how the neural processing captures the most reliable cues is unknown. The interaural time difference (ITD) is the primary cue to localize sound in horizontal space. ITD is encoded in the firing rate of neurons that detect interaural phase difference (IPD). Due to the filtering effect of the head, IPD for a given location varies depending on the environmental context. We found that, in barn owls, at each location there is a frequency range where the head filtering yields the most reliable IPDs across contexts. Remarkably, the frequency tuning of space-specific neurons in the owl's midbrain varies with their preferred sound location, matching the range that carries the most reliable IPD. Thus, frequency tuning in the owl's space-specific neurons reflects a higher-order feature of the code that captures cue reliability. DOI: http://dx.doi.org/10.7554/eLife.04854.001 PMID:25531067

Minimally invasive endoscope-assisted trans-oral excision of huge parapharyngeal space tumors.

PubMed

Li, Shang-Yi; Hsu, Ching-Hui; Chen, Mu-Kuan

2015-04-01

Parapharyngeal space tumors are rare head and neck neoplasms, and most are benign lesions. Complete excision of these tumors is difficult because of the complexity of the surrounding anatomic structures. The algorithm for excision of these tumors is typically based on the tumor's characteristics; excision is performed via approaches such as the trans-oral route, the trans-cervical route, and even a combination of the trans-parotid route and mandibulotomy. However, each of these approaches is associated with some complications. Endoscope-assisted minimally invasive surgery is being increasingly employed for surgeries in the head and neck regions. It has the advantage of leaving no facial scars, and ensures better patient comfort after the operation. Here, we report the use of endoscope-assisted trans-oral surgery for excision of parapharyngeal space tumors. The technique yields an excellent outcome and should be a feasible, safe, and economic method for these patients. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Perforator based rectus free tissue transfer for head and neck reconstruction: New reconstructive advantages from an old friend.

PubMed

Kang, Stephen Y; Spector, Matthew E; Chepeha, Douglas B

2017-11-01

To demonstrate three reconstructive advantages of the perforator based rectus free tissue transfer: long pedicle, customizable adipose tissue, and volume reconstruction without muscle atrophy within a contained space. Thirty patients with defects of the head and neck were reconstructed with the perforator based rectus free tissue transfer. Transplant success was 93%. Mean pedicle length was 13.4cm. Eleven patients (37%) had vessel-poor necks and the long pedicle provided by this transplant avoided the need for vein grafts in these patients. Adipose tissue was molded in 17 patients (57%). Twenty-five patients (83%) had defects within a contained space, such as the orbit, where it was critical to have a transplant that avoided muscle atrophy. The perforator based rectus free tissue transfer provides a long pedicle, moldable fat for flap customization, and is useful in reconstruction of defects within a contained space where volume loss due to muscle atrophy is prevented. Copyright © 2017 Elsevier Ltd. All rights reserved.

David Brock addresses the "How to Launch Your Business with NASA" forum.

NASA Image and Video Library

2017-10-18

The Morgan County Economic Development Association and the City of Decatur, in Partnership with the NASA/Marshall Space Flight Center (MSFC), hosted a business forum on, How to Launch Your Business with NASA, Wednesday, October 18, 2017, at the Alabama Center for the Arts in downtown Decatur, AL. The event was open to all businesses allowed them to connect with Senior NASA representatives and their prime contractors. The program guided businesses through the process of working with NASA as a supplier, subcontractor, and/or a service provider. The Marshall Space Flight Center’s projected procurement budget in FY 2018 is approximately $2.2 billion and numerous procurement opportunities are available for small business participation each fiscal year. The program included Todd May, Director of Marshall Space Flight Center; Johnny Stephenson, Director of Marshall Space Flight Center’s Office of Strategic Analysis and Communication; David Brock, Small Business Specialist with Marshall Space Flight Center; and Lynn Garrison, Small Business Specialist Technical Advisor with Marshall Space Flight Center. Additionally, there was a prime contractor panel consisting of representatives from five NASA prime contractors. The event included a dedicated networking session with those prime contractors. The “Launch Your Business With NASA” event provides those in attendance the opportunity to network with key Marshall Space Flight Center procurement and technical personnel, and representatives of several major Marshall Space Flight Center prime contractors.Arts.. David Brock, head of Marshall's Small Business Office talks about doing business with Marshall.

Human Behaviour in Long-Term Missions

NASA Technical Reports Server (NTRS)

1997-01-01

In this session, Session WP1, the discussion focuses on the following topics: Psychological Support for International Space Station Mission; Psycho-social Training for Man in Space; Study of the Physiological Adaptation of the Crew During A 135-Day Space Simulation; Interpersonal Relationships in Space Simulation, The Long-Term Bed Rest in Head-Down Tilt Position; Psychological Adaptation in Groups of Varying Sizes and Environments; Deviance Among Expeditioners, Defining the Off-Nominal Act in Space and Polar Field Analogs; Getting Effective Sleep in the Space-Station Environment; Human Sleep and Circadian Rhythms are Altered During Spaceflight; and Methodological Approach to Study of Cosmonauts Errors and Its Instrumental Support.

Dependence of auditory spatial updating on vestibular, proprioceptive, and efference copy signals

PubMed Central

Genzel, Daria; Firzlaff, Uwe; Wiegrebe, Lutz

2016-01-01

Humans localize sounds by comparing inputs across the two ears, resulting in a head-centered representation of sound-source position. When the head moves, information about head movement must be combined with the head-centered estimate to correctly update the world-centered sound-source position. Spatial updating has been extensively studied in the visual system, but less is known about how head movement signals interact with binaural information during auditory spatial updating. In the current experiments, listeners compared the world-centered azimuthal position of two sound sources presented before and after a head rotation that depended on condition. In the active condition, subjects rotated their head by ∼35° to the left or right, following a pretrained trajectory. In the passive condition, subjects were rotated along the same trajectory in a rotating chair. In the cancellation condition, subjects rotated their head as in the active condition, but the chair was counter-rotated on the basis of head-tracking data such that the head effectively remained fixed in space while the body rotated beneath it. Subjects updated most accurately in the passive condition but erred in the active and cancellation conditions. Performance is interpreted as reflecting the accuracy of perceived head rotation across conditions, which is modeled as a linear combination of proprioceptive/efference copy signals and vestibular signals. Resulting weights suggest that auditory updating is dominated by vestibular signals but with significant contributions from proprioception/efference copy. Overall, results shed light on the interplay of sensory and motor signals that determine the accuracy of auditory spatial updating. PMID:27169504

Dependence of auditory spatial updating on vestibular, proprioceptive, and efference copy signals.

PubMed

Genzel, Daria; Firzlaff, Uwe; Wiegrebe, Lutz; MacNeilage, Paul R

2016-08-01

Humans localize sounds by comparing inputs across the two ears, resulting in a head-centered representation of sound-source position. When the head moves, information about head movement must be combined with the head-centered estimate to correctly update the world-centered sound-source position. Spatial updating has been extensively studied in the visual system, but less is known about how head movement signals interact with binaural information during auditory spatial updating. In the current experiments, listeners compared the world-centered azimuthal position of two sound sources presented before and after a head rotation that depended on condition. In the active condition, subjects rotated their head by ∼35° to the left or right, following a pretrained trajectory. In the passive condition, subjects were rotated along the same trajectory in a rotating chair. In the cancellation condition, subjects rotated their head as in the active condition, but the chair was counter-rotated on the basis of head-tracking data such that the head effectively remained fixed in space while the body rotated beneath it. Subjects updated most accurately in the passive condition but erred in the active and cancellation conditions. Performance is interpreted as reflecting the accuracy of perceived head rotation across conditions, which is modeled as a linear combination of proprioceptive/efference copy signals and vestibular signals. Resulting weights suggest that auditory updating is dominated by vestibular signals but with significant contributions from proprioception/efference copy. Overall, results shed light on the interplay of sensory and motor signals that determine the accuracy of auditory spatial updating. Copyright © 2016 the American Physiological Society.

Concurrent 3-D sonifications enable the head-up monitoring of two interrelated aircraft navigation instruments.

PubMed

Towers, John; Burgess-Limerick, Robin; Riek, Stephan

2014-12-01

The aim of this study was to enable the head-up monitoring of two interrelated aircraft navigation instruments by developing a 3-D auditory display that encodes this navigation information within two spatially discrete sonifications. Head-up monitoring of aircraft navigation information utilizing 3-D audio displays, particularly involving concurrently presented sonifications, requires additional research. A flight simulator's head-down waypoint bearing and course deviation instrument readouts were conveyed to participants via a 3-D auditory display. Both readouts were separately represented by a colocated pair of continuous sounds, one fixed and the other varying in pitch, which together encoded the instrument value's deviation from the norm. Each sound pair's position in the listening space indicated the left/right parameter of its instrument's readout. Participants' accuracy in navigating a predetermined flight plan was evaluated while performing a head-up task involving the detection of visual flares in the out-of-cockpit scene. The auditory display significantly improved aircraft heading and course deviation accuracy, head-up time, and flare detections. Head tracking did not improve performance by providing participants with the ability to orient potentially conflicting sounds, suggesting that the use of integrated localizing cues was successful. Conclusion: A supplementary 3-D auditory display enabled effective head-up monitoring of interrelated navigation information normally attended to through a head-down display. Pilots operating aircraft, such as helicopters and unmanned aerial vehicles, may benefit from a supplementary auditory display because they navigate in two dimensions while performing head-up, out-of-aircraft, visual tasks.

Lessons from a tarantula: new insights into muscle thick filament and myosin interacting-heads motif structure and function.

PubMed

Alamo, Lorenzo; Koubassova, Natalia; Pinto, Antonio; Gillilan, Richard; Tsaturyan, Andrey; Padrón, Raúl

2017-10-01

The tarantula skeletal muscle X-ray diffraction pattern suggested that the myosin heads were helically arranged on the thick filaments. Electron microscopy (EM) of negatively stained relaxed tarantula thick filaments revealed four helices of heads allowing a helical 3D reconstruction. Due to its low resolution (5.0 nm), the unambiguous interpretation of densities of both heads was not possible. A resolution increase up to 2.5 nm, achieved by cryo-EM of frozen-hydrated relaxed thick filaments and an iterative helical real space reconstruction, allowed the resolving of both heads. The two heads, "free" and "blocked", formed an asymmetric structure named the "interacting-heads motif" (IHM) which explained relaxation by self-inhibition of both heads ATPases. This finding made tarantula an exemplar system for thick filament structure and function studies. Heads were shown to be released and disordered by Ca 2+ -activation through myosin regulatory light chain phosphorylation, leading to EM, small angle X-ray diffraction and scattering, and spectroscopic and biochemical studies of the IHM structure and function. The results from these studies have consequent implications for understanding and explaining myosin super-relaxed state and thick filament activation and regulation. A cooperative phosphorylation mechanism for activation in tarantula skeletal muscle, involving swaying constitutively Ser35 mono-phosphorylated free heads, explains super-relaxation, force potentiation and post-tetanic potentiation through Ser45 mono-phosphorylated blocked heads. Based on this mechanism, we propose a swaying-swinging, tilting crossbridge-sliding filament for tarantula muscle contraction.

Participants in the First Florida Summit at the KSC Visitor Complex.

NASA Technical Reports Server (NTRS)

2000-01-01

Participants in the First Florida Space Summit take part in a discussion on the future of space as it relates to the State of Florida. The discussion, held at the Kennedy Space Center Visitor Complex, was moderated by Center Director Roy Bridges. Seated (left to right) are Representative Jim Davis, Secretary of Transportation Tom Barry and Rick Stephens, who represented The Boeing Company. The event also included Senator Bob Graham, Senator Connie Mack, Representative Dave Weldon, 45th Space Wing Commander Brig. Gen. Donald Pettit and heads of aerospace companies.

KSC-08pd0677

NASA Image and Video Library

2008-03-10

KENNEDY SPACE CENTER, FLA. -- STS-123 Mission Specialist Takao Doi of the Japan Aerospace Exploration Agency dons his launch and entry suit before heading to Launch Pad 39A for liftoff on space shuttle Endeavour. The crew will make a record-breaking 16-day mission to the International Space Station. On STS-123, Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Launch is scheduled for 2:28 a.m. EDT March 11. Photo credit: NASA/Kim Shiflett

Information requirements and methodology for development of an EVA crewmember's heads up display

NASA Astrophysics Data System (ADS)

Petrek, J. S.

This paper presents a systematic approach for developing a Heads Up Display (HUD) to be used within the helmet of the Extra Vehicular Activity (EVA) crewmember. The information displayed on the EVA HUD will be analogous to EVA Flight Data File (FDF) information, which is an integral part of NASA's current Space Transportation System. Another objective is to determine information requirements and media techniques ultimately leading to the helmet-mounted HUD presentation technique.

Induction Heating Systems

NASA Technical Reports Server (NTRS)

1991-01-01

Induction heating technology, a magnetic non-deforming process, was developed by Langley researchers to join plastic and composite components in space. Under NASA license, Inductron Corporation uses the process to produce induction heating systems and equipment for numerous applications. The Torobonder, a portable system, comes with a number of interchangeable heads for aircraft repair. Other developments are the E Heating Head, the Toroid Joining Gun, and the Torobrazer. These products perform bonding applications more quickly, safely and efficiently than previous methods.

Saturn Apollo Program

NASA Image and Video Library

1964-09-01

This photograph shows the components for the Saturn V S-IC stage fuel tank assembly in the Manufacturing Engineering Laboratory, building 4707, at the Marshall Space Flight Center (MSFC). Left to right are upper head, lower head, and forward skirt assembly. Thirty-three feet in diameter, they will hold a total of 4,400,000 pounds of fuel. Although this tankage was assembled at MSFC, the elements were made by the Boeing Company at Wichita and the Michould Operations at New Orleans.

Concept and Technology Exploration for Transparent Hearing

DTIC Science & Technology

2003-05-01

be seen by considering the situation in which the space is anechoic and the listener is modeled by a spherical head with ears at the ends of a ...relatively subtle changes in HRTF’s that cause only minor effects on spatial behavior , such as when a listener puts on a hat, changes their head posture...insufficient, and localization behavior can break down nearly completely [63]. However, with sufficient exposure (e.g. continuous over a period of weeks

A versatile system for biological and soil chemical tests on a planetary landing craft. II - Hardware development

NASA Technical Reports Server (NTRS)

Martin, J. P.; Kok, B.; Radmer, R.

1976-01-01

A system has been under development which is designed to seek remotely for clues to life in planetary soil samples. The basic approach is a set of experiments, all having a common sensor, a gas analysis mass spectrometer which monitors gas composition in the head spaces above sealed, temperature controlled soil samples. Versatility is obtained with up to three preloaded, sealed fluid injector capsules for each of eleven soil test cells. Tests results with an engineering model has demonstrated performance capability of subsystem components such as soil distribution, gas sampling valves, injector mechanisms, temperature control, and test cell seal.

Human Centered Hardware Modeling and Collaboration

NASA Technical Reports Server (NTRS)

Stambolian Damon; Lawrence, Brad; Stelges, Katrine; Henderson, Gena

2013-01-01

In order to collaborate engineering designs among NASA Centers and customers, to in clude hardware and human activities from multiple remote locations, live human-centered modeling and collaboration across several sites has been successfully facilitated by Kennedy Space Center. The focus of this paper includes innovative a pproaches to engineering design analyses and training, along with research being conducted to apply new technologies for tracking, immersing, and evaluating humans as well as rocket, vehic le, component, or faci lity hardware utilizing high resolution cameras, motion tracking, ergonomic analysis, biomedical monitoring, wor k instruction integration, head-mounted displays, and other innovative human-system integration modeling, simulation, and collaboration applications.

Terrain Portrayal for Synthetic Vision Systems Head-Down Displays Evaluation Results

NASA Technical Reports Server (NTRS)

Hughes, Monica F.; Glaab, Louis J.

2007-01-01

A critical component of SVS displays is the appropriate presentation of terrain to the pilot. At the time of this study, the relationship between the complexity of the terrain presentation and resulting enhancements of pilot SA and pilot performance had been largely undefined. The terrain portrayal for SVS head-down displays (TP-HDD) simulation examined the effects of two primary elements of terrain portrayal on the primary flight display (PFD): variations of digital elevation model (DEM) resolution and terrain texturing. Variations in DEM resolution ranged from sparsely spaced (30 arc-sec) to very closely spaced data (1 arc-sec). Variations in texture involved three primary methods: constant color, elevation-based generic, and photo-realistic, along with a secondary depth cue enhancer in the form of a fishnet grid overlay.

STS-55 Columbia, OV-102, mated to ET and SRBs, heads to KSC LC during rollout

NASA Technical Reports Server (NTRS)

1993-01-01

German payload processing team members watch as STS-55 Columbia, Orbiter Vehicle (OV) 102, mated to the external tank (ET) and solid rocket boosters (SRBs), heads to Kennedy Space Center (KSC) Launch Complex (LC) Pad 39A. OV-102, the ET, and SRBs ride atop the mobile launch platform and the crawler transporter. A spectator in the foreground is wearing an STS-55 t-shirt. The German-managed Spacelab Deutsche 2 (SL-D2) and the Unique Support Structure (USS) are already integrated in OV-102's payload bay as it makes its way to LC Pad 39A. OV-102 is targeted for liftoff on Space Shuttle Mission STS-55 in late February. View provided by KSC with alternate KSC number KSC-93PC-283.

Testbed for remote telepresence research

NASA Astrophysics Data System (ADS)

Adnan, Sarmad; Cheatham, John B., Jr.

1992-11-01

Teleoperated robots offer solutions to problems associated with operations in remote and unknown environments, such as space. Teleoperated robots can perform tasks related to inspection, maintenance, and retrieval. A video camera can be used to provide some assistance in teleoperations, but for fine manipulation and control, a telepresence system that gives the operator a sense of actually being at the remote location is more desirable. A telepresence system comprised of a head-tracking stereo camera system, a kinematically redundant arm, and an omnidirectional mobile robot has been developed at the mechanical engineering department at Rice University. This paper describes the design and implementation of this system, its control hardware, and software. The mobile omnidirectional robot has three independent degrees of freedom that permit independent control of translation and rotation, thereby simulating a free flying robot in a plane. The kinematically redundant robot arm has eight degrees of freedom that assist in obstacle and singularity avoidance. The on-board control computers permit control of the robot from the dual hand controllers via a radio modem system. A head-mounted display system provides the user with a stereo view from a pair of cameras attached to the mobile robotics system. The head tracking camera system moves stereo cameras mounted on a three degree of freedom platform to coordinate with the operator's head movements. This telepresence system provides a framework for research in remote telepresence, and teleoperations for space.

Crystallographic and theoretical studies of an inclusion complex of β-cyclodextrin with fentanyl.

PubMed

Ogawa, Noriko; Nagase, Hiromasa; Loftsson, Thorsteinn; Endo, Tomohiro; Takahashi, Chisato; Kawashima, Yoshiaki; Ueda, Haruhisa; Yamamoto, Hiromitsu

2017-10-15

The crystal structure of an inclusion complex of β-cyclodextrin (β-CD) with fentanyl was determined by single crystal X-ray diffraction analysis. The crystal belongs to the triclinic space group P1 and the complex comprises one fentanyl, two β-CD, and several water molecules. β-CD and fentanyl form a host-guest inclusion complex at a ratio of 2:1 and the asymmetric unit of the complex contains two host molecules (β-CDs) in a head-to-head arrangement that form dimers through hydrogen bonds between the secondary hydroxyl groups of β-CD and one guest molecule. Fentanyl is totally contained within the β-CD cavity and the structure of the phenylethyl part of fentanyl inside the dimeric cavity of the complex is disordered. Furthermore, theoretical molecular conformational calculations were conducted to clarify the mobility of the guest molecule in the β-CD cavity using CONFLEX software. Crystal optimization and crystal energy calculations were also conducted. The results of the theoretical calculations confirmed that the conformation of disorder part 1, which was high in occupancy by crystal structure analysis, was more stable. The phenylethyl part of fentanyl existed in several stable conformations. Copyright © 2017 Elsevier B.V. All rights reserved.

Numerical Simulation and Validation of a High Head Model Francis Turbine at Part Load Operating Condition

NASA Astrophysics Data System (ADS)

Goyal, Rahul; Trivedi, Chirag; Kumar Gandhi, Bhupendra; Cervantes, Michel J.

2017-07-01

Hydraulic turbines are operated over an extended operating range to meet the real time electricity demand. Turbines operated at part load have flow parameters not matching the designed ones. This results in unstable flow conditions in the runner and draft tube developing low frequency and high amplitude pressure pulsations. The unsteady pressure pulsations affect the dynamic stability of the turbine and cause additional fatigue. The work presented in this paper discusses the flow field investigation of a high head model Francis turbine at part load: 50% of the rated load. Numerical simulation of the complete turbine has been performed. Unsteady pressure pulsations in the vaneless space, runner, and draft tube are investigated and validated with available experimental data. Detailed analysis of the rotor stator interaction and draft tube flow field are performed and discussed. The analysis shows the presence of a rotating vortex rope in the draft tube at the frequency of 0.3 times of the runner rotational frequency. The frequency of the vortex rope precession, which causes severe fluctuations and vibrations in the draft tube, is predicted within 3.9% of the experimental measured value. The vortex rope results pressure pulsations propagating in the system whose frequency is also perceive in the runner and upstream the runner.

Inspection In Overhead Spaces Containing Asbestos

NASA Technical Reports Server (NTRS)

Bell, Jacque; Hartwick, George; Hutcherson, Jerry

1989-01-01

Procedure for inspection in spaces above dropped ceilings that contain asbestos saves time and effort without sacrificing safety. With new method, only items of safety equipment needed are glove bag, storage bag, and roll of adhesive tape. Inspector tapes glove bag tightly to support grid around ceiling tile to be removed. With hands in gloves inspector lifts tile gently and places it aside. Extending head and shoulders into bag, inspector examines space above ceiling with help of flashlight.

Comparison of Video Head Impulse Test (vHIT) Gains Between Two Commercially Available Devices and by Different Gain Analytical Methods.

PubMed

Lee, Sang Hun; Yoo, Myung Hoon; Park, Jun Woo; Kang, Byung Chul; Yang, Chan Joo; Kang, Woo Suk; Ahn, Joong Ho; Chung, Jong Woo; Park, Hong Ju

2018-06-01

To evaluate whether video head impulse test (vHIT) gains are dependent on the measuring device and method of analysis. Prospective study. vHIT was performed in 25 healthy subjects using two devices simultaneously. vHIT gains were compared between these instruments and using five different methods of comparing position and velocity gains during head movement intervals. The two devices produced different vHIT gain results with the same method of analysis. There were also significant differences in the vHIT gains measured using different analytical methods. The gain analytic method that compares the areas under the velocity curve (AUC) of the head and eye movements during head movements showed lower vHIT gains than a method that compared the peak velocities of the head and eye movements. The former method produced the vHIT gain with the smallest standard deviation among the five procedures tested in this study. vHIT gains differ in normal subjects depending on the device and method of analysis used, suggesting that it is advisable for each device to have its own normal values. Gain calculations that compare the AUC of the head and eye movements during the head movements show the smallest variance.

Compact and mobile high resolution PET brain imager

DOEpatents

Majewski, Stanislaw [Yorktown, VA; Proffitt, James [Newport News, VA

2011-02-08

A brain imager includes a compact ring-like static PET imager mounted in a helmet-like structure. When attached to a patient's head, the helmet-like brain imager maintains the relative head-to-imager geometry fixed through the whole imaging procedure. The brain imaging helmet contains radiation sensors and minimal front-end electronics. A flexible mechanical suspension/harness system supports the weight of the helmet thereby allowing for patient to have limited movements of the head during imaging scans. The compact ring-like PET imager enables very high resolution imaging of neurological brain functions, cancer, and effects of trauma using a rather simple mobile scanner with limited space needs for use and storage.

The Impact of Head Start on Children, Families and Communities. Final Report of the Head Start Evaluation, Synthesis and Utilization Project.

ERIC Educational Resources Information Center

McKey, Ruth Hubbell; And Others

Including all Head Start research (both published and unpublished) and using, when possible, the statistical technique of meta-analysis, this final report of the Head Start Evaluation, Synthesis, and Utilization Project presents findings on the impact of Head Start on children's cognitive and socioemotional development, on child health and health…

The Two Faces of Secondary Headship: Women Deputy Head Teachers' Perceptions of the Secondary Head Teacher Role

ERIC Educational Resources Information Center

Guihen, Laura

2017-01-01

Men continue to outnumber women at the secondary head teacher level. This article reports on some of the preliminary findings of a larger study exploring the ways in which women deputy head teachers, as potential aspirants to headship, perceive the secondary head teacher role. Using an Interpretative Phenomenological Analysis methodology,…

Two-Year versus One-Year Head Start Program Impact: Addressing Selection Bias by Comparing Regression Modeling with Propensity Score Analysis

ERIC Educational Resources Information Center

Leow, Christine; Wen, Xiaoli; Korfmacher, Jon

2015-01-01

This article compares regression modeling and propensity score analysis as different types of statistical techniques used in addressing selection bias when estimating the impact of two-year versus one-year Head Start on children's school readiness. The analyses were based on the national Head Start secondary dataset. After controlling for…

Recognition of anaerobic bacterial isolates in vitro using electronic nose technology.

PubMed

Pavlou, A; Turner, A P F; Magan, N

2002-01-01

Use of an electronic nose (e.nose) system to differentiation between anaerobic bacteria grown in vitro on agar media. Cultures of Clostridium spp. (14 strains) and Bacteroides fragilis (12 strains) were grown on blood agar plates and incubated in sampling bags for 30 min before head space analysis of the volatiles. Qualitative analyses of the volatile production patterns was carried out using an e.nose system with 14 conducting polymer sensors. Using data analysis techniques such as principal components analysis (PCA), genetic algorithms and neural networks it was possible to differentiate between agar blanks and individual species which accounted for all the data. A total of eight unknowns were correctly discriminated into the bacterial groups. This is the first report of in vitro complex volatile pattern recognition and differentiation of anaerobic pathogens. These results suggest the potential for application of e.nose technology in early diagnosis of microbial pathogens of medical importance.

Integrated approach for stress analysis of high performance diesel engine cylinder head

NASA Astrophysics Data System (ADS)

Chainov, N. D.; Myagkov, L. L.; Malastowski, N. S.; Blinov, A. S.

2018-03-01

Growing thermal and mechanical loads due to development of engines with high level of a mean effective pressure determine requirements to cylinder head durability. In this paper, computational schemes for thermal and mechanical stress analysis of a high performance diesel engine cylinder head were described. The most important aspects in this approach are the account of temperature fields of conjugated details (valves and saddles), heat transfer modeling in a cooling jacket of a cylinder head and topology optimization of the detail force scheme. Simulation results are shown and analyzed.

[Measurement and analysis of human head-face dimensions].

PubMed

DU, Li-Li; Wang, Li-Min; Zhuang, Ziqing

2008-05-01

To probe into the physical changes on the head and face of Chinese adults, find the representative indexes and provide references for head-face products design especially in the field of labor protection. The ISO7250-1996 and GB/T5703-99 Basic Human Body Measurements for Technological Design was used. Twenty items of head-face referential parameters and 4 items of body indexes (height, weight, waist circumference and buttock circumference) were measured by using sliding caliper, spreading caliper and pupillometer. The populations were sampled by age, gender and region and their influences on the head and face dimensions were statistically analyzed. By studying the relationship between these parameters with correlation and cluster analysis, the representative indexes of head and face dimensions were concluded. 3000 objectives (2026 men and 974 women) were involved in this survey. The results enunciated that the values of the items in male were larger than those in female. For example, the mean values of face length, face width, jaw width, lip length and nose protrusion were 117.0, 147.6, 118.5, 51.7, 18.7 mm for male and 109.7, 140.1, 114.5, 49.3, 17.7 mm for female. The regional disparity and obesity were significant factors. The sizes of head and face of north-eastern population were significantly bigger than those of south-western population except of maximum length of head, the length of lip and face configuration length. The sizes of head and face of obesity population were significantly bigger than those of non-obesity population (P < 0.01). By the cluster analysis, five representative indexes (face length, face width, jaw width, lip length and nose protrusion) were obtained. Further correction analysis suggested that these indexes could well represent the head-face dimensions. The influence of gender, region and obesity on the head-face dimensions is significant. The age is not a significant influential factor. Five representative indexes (face length, face width, jaw width, lip length and nose protrusion) are obtained to provide foundation in the standard design of head-face products.

Effects of Head Rotation on Space- and Word-Based Reading Errors in Spatial Neglect

ERIC Educational Resources Information Center

Reinhart, Stefan; Keller, Ingo; Kerkhoff, Georg

2010-01-01

Patients with right hemisphere lesions often omit or misread words on the left side of a text or the beginning letters of single words which is termed neglect dyslexia (ND). Two types of reading errors are typically observed in ND: omissions and word-based reading errors. The prior are considered as space-based omission errors on the…

KSC-02pd0434

NASA Image and Video Library

2002-03-29

KENNEDY SPACE CENTER, FLA. - Water droplets fall from the broad bill of a Roseate Spoonbill after lifting its head from the water. The site is near Kennedy Space Center. Spoonbills obtain food by sweeping their broad bills from side to side. They inhabit mangroves, ranging from the coasts of southern Florida and Texas (sometimes Louisiana), the West Indies, Mexico and Central and South America.

Development of head injury assessment reference values based on NASA injury modeling.

PubMed

Somers, Jeffrey T; Granderson, Bradley; Melvin, John W; Tabiei, Ala; Lawrence, Charles; Feiveson, Alan; Gernhardt, Michael; Ploutz-Snyder, Robert; Patalak, John

2011-11-01

NASA is developing a new crewed vehicle and desires a lower risk of injury compared to automotive or commercial aviation. Through an agreement with the National Association of Stock Car Auto Racing, Inc. (NASCAR®), an analysis of NASCAR impacts was performed to develop new injury assessment reference values (IARV) that may be more relevant to NASA's context of vehicle landing operations. Head IARVs associated with race car impacts were investigated by analyzing all NASCAR recorded impact data for the 2002-2008 race seasons. From the 4015 impact files, 274 impacts were selected for numerical simulation using a custom NASCAR restraint system and Hybrid III 50th percentile male Finite Element Model (FEM) in LS-DYNA. Head injury occurred in 27 of the 274 selected impacts, and all of the head injuries were mild concussions with or without brief loss of consciousness. The 247 noninjury impacts selected were representative of the range of crash dynamics present in the total set of impacts. The probability of head injury was estimated for each metric using an ordered probit regression analysis. Four metrics had good correlation with the head injury data: head resultant acceleration, head change in velocity, HIC 15, and HIC 36. For a 5% risk of AIS≥1/AIS≥2 head injuries, the following IARVs were found: 121.3/133.2 G (head resultant acceleration), 20.3/22.0 m/s (head change in velocity), 1,156/1,347 (HIC 15), and 1,152/1,342 (HIC 36) respectively. Based on the results of this study, further analysis of additional datasets is recommended before applying these results to future NASA vehicles.

Multiple regression analysis of anthropometric measurements influencing the cephalic index of male Japanese university students.

PubMed

Hossain, Md Golam; Saw, Aik; Alam, Rashidul; Ohtsuki, Fumio; Kamarul, Tunku

2013-09-01

Cephalic index (CI), the ratio of head breadth to head length, is widely used to categorise human populations. The aim of this study was to access the impact of anthropometric measurements on the CI of male Japanese university students. This study included 1,215 male university students from Tokyo and Kyoto, selected using convenient sampling. Multiple regression analysis was used to determine the effect of anthropometric measurements on CI. The variance inflation factor (VIF) showed no evidence of a multicollinearity problem among independent variables. The coefficients of the regression line demonstrated a significant positive relationship between CI and minimum frontal breadth (p < 0.01), bizygomatic breadth (p < 0.01) and head height (p < 0.05), and a negative relationship between CI and morphological facial height (p < 0.01) and head circumference (p < 0.01). Moreover, the coefficient and odds ratio of logistic regression analysis showed a greater likelihood for minimum frontal breadth (p < 0.01) and bizygomatic breadth (p < 0.01) to predict round-headedness, and morphological facial height (p < 0.05) and head circumference (p < 0.01) to predict long-headedness. Stepwise regression analysis revealed bizygomatic breadth, head circumference, minimum frontal breadth, head height and morphological facial height to be the best predictor craniofacial measurements with respect to CI. The results suggest that most of the variables considered in this study appear to influence the CI of adult male Japanese students.

Demonstration of the ExoMars sample preparation and distribution system jointly with an optical instrument head

NASA Astrophysics Data System (ADS)

Schulte, Wolfgang; Thiele, Hans; Hofmann, Peter; Baglioni, Pietro

The ExoMars program will search for past and present life on Mars. ExoMars will address important scientific goals and demonstrate key in-situ enabling technologies. Among such technologies are the acquisition, preparation, distribution and analysis of samples from Mars surface rocks and from the subsurface. The 2018 mission will land an ESA rover on Mars which carries a sample preparation and distribution system (SPDS) and a suite of analytical instruments, the Pasteur Payload with its Analytical Laboratory Drawer (ALD). Kayser-Threde GmbH (Germany) will be responsible for the SPDS as a subcontractor under the mission prime Thales Alenia Space. The SPDS comprises a number of complex mechanisms and mechanical devices designed to transport drill core samples within the rover analytical laboratory, to crush them to powder with a fine grain size, to portion discrete amounts of powdered sample material, to distribute and fill the material into sample containers and to prepare flat sample surfaces for scientific analysis. Breadboards of the crushing mechanism, the dosing mechanism and a distribution carousel with sample containers and a powder sample surface flattening mechanism were built and tested. Kayser-Threde, as a member of the Spanish led ExoMars Raman Instrument team, is also responsible for development of the Raman optical head, which will be mounted inside ALD and will inspect the crushed samples, when they are presented to the instrument by the distribution carousel. Within this activity, which is performed under contract with the Institute of Physical Chemistry of the University of Jena (Germany) and funded by the German DLR, Kayser-Threde can demonstrate Raman measurements with the optical head and a COTS laser and spectrometer and thus simulate the full Raman instrument optical path. An autofocus system with actuator and feedback optics is also part of this activity, which allows focusing the 50 m Raman spot on the surface of the powdered sample. Availability of both, the SPDS mechanisms and the Raman Spectrometer optical head at Kayser-Threde facilities allowed to demonstrate for the first time a sample preparation chain with a joint operation of the optical head. Mineral samples were crushed, dosed into sample containers on the carousel, flattened and then inspected by the Raman optical head. The samples were provided by the University of Jena, a member of the ExoMars Raman science team. This paper will give an overview of the breadboards developed so far for the ExoMars SPDS and the Raman optical head and illustrate the joint demonstration test setup of the SPDS with the instrument. The different behavior of different sample materials will be highlighted and first conclusions will be drawn on what could be learned from test setups combining the ExoMars SPDS and analytical instruments.

Size And Shape of Detergent Micelles Determined By Small-Angle X-Ray Scattering

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

Lipfert, Jan; Columbus, Linda; Chu, Vincent B.

2009-04-29

We present a systematic analysis of the aggregation number and shape of micelles formed by nine detergents commonly used in the study of membrane proteins. Small-angle X-ray scattering measurements are reported for glucosides with 8 and 9 alkyl carbons (OG/NG), maltosides and phosphocholines with 10 and 12 alkyl carbons (DM/DDM and FC-10/FC-12), 1,2-dihexanoyl-sn-glycero-phosphocholine (DHPC), 1-palmitoyl-2-hydroxy-sn-glycero-3-[phospho-rac-(1-glycerol)] (LPPG), and 3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonate (CHAPS). The SAXS intensities are well described by two-component ellipsoid models, with a dense outer shell corresponding to the detergent head groups and a less electron dense hydrophobic core. These models provide an intermediate resolution view of micelle size and shape.more » In addition, we show that Guinier analysis of the forward scattering intensity can be used to obtain an independent and model-free measurement of the micelle aggregation number and radius of gyration. This approach has the advantage of being easily generalizable to protein-detergent complexes, where simple geometric models are inapplicable. Furthermore, we have discovered that the position of the second maximum in the scattering intensity provides a direct measurement of the characteristic head group-head group spacing across the micelle core. Our results for the micellar aggregation numbers and dimensions agree favorably with literature values as far as they are available. We de novo determine the shape of FC-10, FC-12, DM, LPPG, and CHAPS micelles and the aggregation numbers of FC-10 and OG to be ca. 50 and 250, respectively. Combined, these data provide a comprehensive view of the determinants of micelle formation and serve as a starting point to correlate detergent properties with detergent-protein interactions.« less

Proteomic analysis of honeybee (Apis mellifera L.) pupae head development.

PubMed

Zheng, Aijuan; Li, Jianke; Begna, Desalegn; Fang, Yu; Feng, Mao; Song, Feifei

2011-01-01

The honeybee pupae development influences its future adult condition as well as honey and royal jelly productions. However, the molecular mechanism that regulates honeybee pupae head metamorphosis is still poorly understood. To further our understand of the associated molecular mechanism, we investigated the protein change of the honeybee pupae head at 5 time-points using 2-D electrophoresis, mass spectrometry, bioinformatics, quantitative real-time polymerase chain reaction and Western blot analysis. Accordingly, 58 protein spots altered their expression across the 5 time points (13-20 days), of which 36 proteins involved in the head organogenesis were upregulated during early stages (13-17 days). However, 22 proteins involved in regulating the pupae head neuron and gland development were upregulated at later developmental stages (19-20 days). Also, the functional enrichment analysis further suggests that proteins related to carbohydrate metabolism and energy production, development, cytoskeleton and protein folding were highly involved in the generation of organs and development of honeybee pupal head. Furthermore, the constructed protein interaction network predicted 33 proteins acting as key nodes of honeybee pupae head growth of which 9 and 4 proteins were validated at gene and protein levels, respectively. In this study, we uncovered potential protein species involved in the formation of honeybee pupae head development along with their specific temporal requirements. This first proteomic result allows deeper understanding of the proteome profile changes during honeybee pupae head development and provides important potential candidate proteins for future reverse genetic research on honeybee pupae head development to improve the performance of related organs.

The relationship between temporomandibular dysfunction and head and cervical posture.

PubMed

Matheus, Ricardo Alves; Ramos-Perez, Flávia Maria de Moraes; Menezes, Alynne Vieira; Ambrosano, Gláucia Maria Bovi; Haiter-Neto, Francisco; Bóscolo, Frab Norberto; de Almeida, Solange Maria

2009-01-01

This study aimed to evaluate the possibility of any correlation between disc displacement and parameters used for evaluation of skull positioning in relation to the cervical spine: craniocervical angle, suboccipital space between C0-C1, cervical curvature and position of the hyoid bone in individuals with and without symptoms of temporomandibular dysfunction. The patients were evaluated following the guidelines set forth by RDC/TMD. Evaluation was performed by magnetic resonance imaging for establishment of disc positioning in the temporomandibular joints (TMJs) of 30 volunteer patients without temporomandibular dysfunction symptoms and 30 patients with symptoms. Evaluation of skull positioning in relation to the cervical spine was performed on lateral cephalograms achieved with the individual in natural head position. Data were submitted to statistical analysis by Fisher's exact test at 5% significance level. To measure the degree of reproducibility/agreements between surveys, the kappa (K) statistics was used. Significant differences were observed between C0-C1 measurement for both symptomatic (p=0.04) and asymptomatic (p=0.02). No statistical differences were observed regarding craniocervical angle, C1-C2 and hyoid bone position in relation to the TMJs with and without disc displacement. Although statistically significant difference was found in the C0-C1 space, no association between these and internal temporomandibular joint disorder can be considered. Based on the results observed in this study, no direct relationship could be determined between the presence of disc displacement and the variables assessed.

THE RELATIONSHIP BETWEEN TEMPOROMANDIBULAR DYSFUNCTION AND HEAD AND CERVICAL POSTURE

PubMed Central

Matheus, Ricardo Alves; Ramos-Perez, Flávia Maria de Moraes; Menezes, Alynne Vieira; Ambrosano, Gláucia Maria Bovi; Haiter, Francisco; Bóscolo, Frab Norberto; de Almeida, Solange Maria

2009-01-01

Objective: This study aimed to evaluate the possibility of any correlation between disc displacement and parameters used for evaluation of skull positioning in relation to the cervical spine: craniocervical angle, suboccipital space between C0-C1, cervical curvature and position of the hyoid bone in individuals with and without symptoms of temporomandibular dysfunction. Material and Methods: The patients were evaluated following the guidelines set forth by RDC/TMD. Evaluation was performed by magnetic resonance imaging for establishment of disc positioning in the temporomandibular joints (TMJs) of 30 volunteer patients without temporomandibular dysfunction symptoms and 30 patients with symptoms. Evaluation of skull positioning in relation to the cervical spine was performed on lateral cephalograms achieved with the individual in natural head position. Data were submitted to statistical analysis by Fisher's exact test at 5% significance level. To measure the degree of reproducibility/agreements between surveys, the kappa (K) statistics was used. Results: Significant differences were observed between C0-C1 measurement for both symptomatic (p=0.04) and asymptomatic (p=0.02). No statistical differences were observed regarding craniocervical angle, C1-C2 and hyoid bone position in relation to the TMJs with and without disc displacement. Although statistically significant difference was found in the C0-C1 space, no association between these and internal temporomandibular joint disorder can be considered. Conclusion: Based on the results observed in this study, no direct relationship could be determined between the presence of disc displacement and the variables assessed. PMID:19466252

Analysis of the variation in OCT measurements of a structural bottle neck for eye-brain transfer of visual information from 3D-volumes of the optic nerve head, PIMD-Average [02π

NASA Astrophysics Data System (ADS)

Söderberg, Per G.; Malmberg, Filip; Sandberg-Melin, Camilla

2016-03-01

The present study aimed to analyze the clinical usefulness of the thinnest cross section of the nerve fibers in the optic nerve head averaged over the circumference of the optic nerve head. 3D volumes of the optic nerve head of the same eye was captured at two different visits spaced in time by 1-4 weeks, in 13 subjects diagnosed with early to moderate glaucoma. At each visit 3 volumes containing the optic nerve head were captured independently with a Topcon OCT- 2000 system. In each volume, the average shortest distance between the inner surface of the retina and the central limit of the pigment epithelium around the optic nerve head circumference, PIMD-Average [02π], was determined semiautomatically. The measurements were analyzed with an analysis of variance for estimation of the variance components for subjects, visits, volumes and semi-automatic measurements of PIMD-Average [0;2π]. It was found that the variance for subjects was on the order of five times the variance for visits, and the variance for visits was on the order of 5 times higher than the variance for volumes. The variance for semi-automatic measurements of PIMD-Average [02π] was 3 orders of magnitude lower than the variance for volumes. A 95 % confidence interval for mean PIMD-Average [02π] was estimated to 1.00 +/-0.13 mm (D.f. = 12). The variance estimates indicate that PIMD-Average [02π] is not suitable for comparison between a onetime estimate in a subject and a population reference interval. Cross-sectional independent group comparisons of PIMD-Average [02π] averaged over subjects will require inconveniently large sample sizes. However, cross-sectional independent group comparison of averages of within subject difference between baseline and follow-up can be made with reasonable sample sizes. Assuming a loss rate of 0.1 PIMD-Average [02π] per year and 4 visits per year it was found that approximately 18 months follow up is required before a significant change of PIMDAverage [02π] can be observed with a power of 0.8. This is shorter than what has been observed both for HRT measurements and automated perimetry measurements with a similar observation rate. It is concluded that PIMDAverage [02π] has the potential to detect deterioration of glaucoma quicker than currently available primary diagnostic instruments. To increase the efficiency of PIMD-Average [02π] further, the variation among visits within subject has to be reduced.

Spatio-temporal Evolution of Velocity Structure, Concentration and Grain-size Stratification within Experimental Particulate Gravity Flows: Potential Input Parameters for Numerical Models

NASA Astrophysics Data System (ADS)

McCaffrey, W.; Choux, C.; Baas, J.; Haughton, P.

2001-12-01

Little is known about the combined spatio-temporal evolution of velocity structure, concentration and grain size stratification within particulate gravity currents. Yet these data are of primary importance for numerical model validation, prior to application to natural flows, such as pyroclastic density currents and turbidity currents. A comprehensive study was carried out on a series of experimental particulate gravity flows of 5% by volume initial concentration. The sediment analogue was polydisperse silica flour (mean grain size ~8 microns). A uniform 30 liter suspension was prepared in an overhead reservoir, then allowed to drain (in about one minute) into an flume 10 m long and 0.3 m wide, water-filled to a depth of 0.3 m. Each flow was siphoned continuously for 52 s at 5 different heights (spaced evenly from 0.6 to 4.6 cm) with samples collected at a frequency of 0.25Hz, generating 325 samples for grain-size and concentration analysis. Simultaneously, six 4-MHz UDVP (Ultrasonic Doppler Velocity Profiling) probes recorded the horizontal component of flow velocity. All but the highest probe were positioned at the same height as the siphons. The sampling location was shifted 1.32m down-current for each of five nominally identical flows, yielding sample locations at 1.32, 2.64, 3.96, 5.28 and 6.60m from the inlet point. These data can be combined to give both the temporal and spatial evolution of a single idealised flow. The concentration data can be used to defined the structure of the flow. The flow first propagated as a jet, then became stratified. The length of the head increased with increasing distance from the reservoir (although the head propagation velocity was uniform). The maximum concentration was located at the base of the flow towards the rear of the head. Grain-size analysis showed that the head was enriched in coarse particles even at the most distal sampling location. Distinct flow stratification developed at a distance between 1.3 m and 2.6 m from the reservoir. In the body of the current, the suspended sediment was normally graded, whereas the tail exhibited inverse grading. This inverse grading may be linked to coarse particles in the head being swept upwards and backwards, then falling back into the body of the current. Alternatively, body turbulence may inhibit the settling of coarse particles. Turbulence may also explain the presence of coarse particles in the flow's head, with turbulence intensity apparently correlated with the flow competence.

Effect of component design in retrieved bipolar hip hemiarthroplasty systems.

PubMed

Hess, Matthew D; Baker, Erin A; Salisbury, Meagan R; Kaplan, Lige M; Greene, Ryan T; Greene, Perry W

2013-09-01

Primary articulation of bipolar hemiarthroplasty systems is at the femoral head-liner interface. The purpose of this study was to compare observed damage modes on 36 retrieved bipolar systems with implant, demographic, intraoperative, and radiographic data to elucidate the effects of component design, specifically locking mechanism, on clinical performance. Retrieved bipolar hip hemiarthroplasty systems of 3 different design types were obtained, disassembled, and evaluated macro- and microscopically for varying modes of wear, including abrasion, burnishing, embedding, scratching, and pitting. Clinical record review and radiographic analysis were performed by a senior orthopedic surgery resident. Average bipolar hip hemiarthroplasty system term of service was 46 months (range, 0.27-187 months). All devices contained wear debris captured within the articulating space between the femoral head and liner. In 31% of patients without infection, lucency was observed on immediate prerevision radiographs. The system with a leaf locking mechanism showed significantly increased radiographically observed osteolysis (P=.03) compared with a system with a stopper ring locking mechanism. In addition, implant design and observed damage modes, including pitting and third-body particle embedding, were significantly associated with radiographically observed osteolysis. Copyright 2013, SLACK Incorporated.

Comets: Role and importance to exobiology

NASA Technical Reports Server (NTRS)

Delsemme, Armand H.

1992-01-01

The transfer of organic compounds from interstellar space to the outskirts of a protoplanetary disk, their accretion into cometary objects, and the transport of the latter into the inner solar system by orbital diffusion throw a new light on the central problem of exobiology. It suggests the existence of a cosmic mechanism, working everywhere, that can supply prebiotic compounds to ubiquitous rocky planets, in search of the proper environment to start life in many places in the Universe. Under the heading of chemistry of the cometary nucleus, the following topics are covered: radial homogeneity of the nucleus; the dust-to-ice ratio; nature of the dust grains; origin of the dust in comets; nature of the volatile fraction; the CO distribution in comet Halley; dust contribution to the volatile fraction; elemental balance sheet of comet Halley; quantitative molecular analysis of the volatile fraction; and isotopic ratios. Under the heading of exogenous origin of carbon on terrestrial planets the following topics are covered: evidence for a high-temperature phase; from planetesimals to planets; a veneer of volatile and organic material; and cometary contribution.

CFD Analysis of Tile-Repair Augers for the Shuttle Orbiter Re-Entry Aeroheating

NASA Technical Reports Server (NTRS)

Mazaheri, Ali R.

2007-01-01

A three-dimensional aerothermodynamic model of the shuttle orbiter's tile overlay repair (TOR) sub-assembly is presented. This sub-assembly, which is an overlay that covers the damaged tiles, is modeled as a protuberance with a constant thickness. The washers and augers that serve as the overlay fasteners are modeled as cylindrical protuberances with constant thicknesses. Entry aerothermodynamic cases are studied to provide necessary inputs for future thermal analyses and to support the space-shuttle return-to-flight effort. The NASA Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) is used to calculate heat transfer rate on the surfaces of the tile overlay repair and augers. Gas flow is modeled as non-equilibrium, five species air in thermal equilibrium. Heat transfer rate and surface temperatures are analyzed and studied for a shuttle orbiter trajectory point at Mach 17.85. Computational results show that the average heat transfer rate normalized with respect to its value at body point 1800 is about BF=1.9 for the auger head. It is also shown that the average BF for the auger and washer heads is about BF=2.0.

Stabilization of gaze during circular locomotion in darkness. II. Contribution of velocity storage to compensatory eye and head nystagmus in the running monkey

NASA Technical Reports Server (NTRS)

Solomon, D.; Cohen, B.

1992-01-01

1. Yaw eye in head (Eh) and head on body velocities (Hb) were measured in two monkeys that ran around the perimeter of a circular platform in darkness. The platform was stationary or could be counterrotated to reduce body velocity in space (Bs) while increasing gait velocity on the platform (Bp). The animals were also rotated while seated in a primate chair at eccentric locations to provide linear and angular accelerations similar to those experienced while running. 2. Both animals had head and eye nystagmus while running in darkness during which slow phase gaze velocity on the body (Gb) partially compensated for body velocity in space (Bs). The eyes, driven by the vestibuloocular reflex (VOR), supplied high-frequency characteristics, bringing Gb up to compensatory levels at the beginning and end of the slow phases. The head provided substantial gaze compensation during the slow phases, probably through the vestibulocollic reflex (VCR). Synchronous eye and head quick phases moved gaze in the direction of running. Head movements occurred consistently only when animals were running. This indicates that active body and limb motion may be essential for inducing the head-eye gaze synergy. 3. Gaze compensation was good when running in both directions in one animal and in one direction in the other animal. The animals had long VOR time constants in these directions. The VOR time constant was short to one side in one animal, and it had poor gaze compensation in this direction. Postlocomotory nystagmus was weaker after running in directions with a long VOR time constant than when the animals were passively rotated in darkness. We infer that velocity storage in the vestibular system had been activated to produce continuous Eh and Hb during running and to counteract postrotatory afterresponses. 4. Continuous compensatory gaze nystagmus was not produced by passive eccentric rotation with the head stabilized or free. This indicates that an aspect of active locomotion, most likely somatosensory feedback, was responsible for activating velocity storage. 5. Nystagmus was compared when an animal ran in darkness and in light. the beat frequency of eye and head nystagmus was lower, and the quick phases were larger in darkness. The duration of head and eye quick phases covaried. Eye quick phases were larger when animals ran in darkness than when they were passively rotated. The maximum velocity and duration of eye quick phases were the same in both conditions. 6. The platform was counterrotated under one monkey in darkness while it ran in the direction of its long vestibular time constant.(ABSTRACT TRUNCATED AT 400 WORDS).

Hydrogen Maser Clocks in Space for Solid-Earth Research and Time-Transfer Applications: Experiment Overview and Evaluation of Russian Miniature Sapphire Loaded Cavity,

DTIC Science & Technology

cavity, a technique pioneered at VNIIFTRI . Various contacts between West-European parties, headed by ESA, and the Russian parties, headed by RSA, Led...provided by ON and the other by VNIIFTRI . T/F transfer and precise positioning will be performed by both a microwave link, using PRARE equipment, and...sapphire loaded microwave cavity, on Loan from VNIIFTRI , was evaluated in a full-size EFOS hydrogen maser built by ON. The experimental evaluation

Xenon as a Neuroprotectant in Traumatic Brain Injury

DTIC Science & Technology

2012-03-01

the animal is moving freely about a space), presence or absence of Head Tilt , and Baton (level of coordination used to grasp a stick with all four... Head Tilt (is it present?), and Baton (level of coordination used to grasp a stick with all four feet). Each category is scored on a scale of 0 to 5...the cortical surface, but no impact ensues. Blinding and allocation strategy : Experimental conditions (e.g., impact depth, gas etc) for any given day

Enhanced/synthetic vision and head-worn display technologies for terminal maneuvering area NextGen operations

NASA Astrophysics Data System (ADS)

Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Williams, Steven P.; Bailey, Randall E.; Shelton, Kevin J.; Norman, R. Mike

2011-06-01

NASA is researching innovative technologies for the Next Generation Air Transportation System (NextGen) to provide a "Better-Than-Visual" (BTV) capability as adjunct to "Equivalent Visual Operations" (EVO); that is, airport throughputs equivalent to that normally achieved during Visual Flight Rules (VFR) operations rates with equivalent and better safety in all weather and visibility conditions including Instrument Meteorological Conditions (IMC). These new technologies build on proven flight deck systems and leverage synthetic and enhanced vision systems. Two piloted simulation studies were conducted to access the use of a Head-Worn Display (HWD) with head tracking for synthetic and enhanced vision systems concepts. The first experiment evaluated the use a HWD for equivalent visual operations to San Francisco International Airport (airport identifier: KSFO) compared to a visual concept and a head-down display concept. A second experiment evaluated symbology variations under different visibility conditions using a HWD during taxi operations at Chicago O'Hare airport (airport identifier: KORD). Two experiments were conducted, one in a simulated San Francisco airport (KSFO) approach operation and the other, in simulated Chicago O'Hare surface operations, evaluating enhanced/synthetic vision and head-worn display technologies for NextGen operations. While flying a closely-spaced parallel approach to KSFO, pilots rated the HWD, under low-visibility conditions, equivalent to the out-the-window condition, under unlimited visibility, in terms of situational awareness (SA) and mental workload compared to a head-down enhanced vision system. There were no differences between the 3 display concepts in terms of traffic spacing and distance and the pilot decision-making to land or go-around. For the KORD experiment, the visibility condition was not a factor in pilot's rating of clutter effects from symbology. Several concepts for enhanced implementations of an unlimited field-of-regard BTV concept for low-visibility surface operations were determined to be equivalent in pilot ratings of efficacy and usability.

Enhanced/Synthetic Vision and Head-Worn Display Technologies for Terminal Maneuvering Area NextGen Operations

NASA Technical Reports Server (NTRS)

Arthur, Jarvis J., III; Prinzell, Lawrence J.; Williams, Steven P.; Bailey, Randall E.; Shelton, Kevin J.; Norman, R. Mike

2011-01-01

NASA is researching innovative technologies for the Next Generation Air Transportation System (NextGen) to provide a "Better-Than-Visual" (BTV) capability as adjunct to "Equivalent Visual Operations" (EVO); that is, airport throughputs equivalent to that normally achieved during Visual Flight Rules (VFR) operations rates with equivalent and better safety in all weather and visibility conditions including Instrument Meteorological Conditions (IMC). These new technologies build on proven flight deck systems and leverage synthetic and enhanced vision systems. Two piloted simulation studies were conducted to access the use of a Head-Worn Display (HWD) with head tracking for synthetic and enhanced vision systems concepts. The first experiment evaluated the use a HWD for equivalent visual operations to San Francisco International Airport (airport identifier: KSFO) compared to a visual concept and a head-down display concept. A second experiment evaluated symbology variations under different visibility conditions using a HWD during taxi operations at Chicago O'Hare airport (airport identifier: KORD). Two experiments were conducted, one in a simulated San Francisco airport (KSFO) approach operation and the other, in simulated Chicago O'Hare surface operations, evaluating enhanced/synthetic vision and head-worn display technologies for NextGen operations. While flying a closely-spaced parallel approach to KSFO, pilots rated the HWD, under low-visibility conditions, equivalent to the out-the-window condition, under unlimited visibility, in terms of situational awareness (SA) and mental workload compared to a head-down enhanced vision system. There were no differences between the 3 display concepts in terms of traffic spacing and distance and the pilot decision-making to land or go-around. For the KORD experiment, the visibility condition was not a factor in pilot's rating of clutter effects from symbology. Several concepts for enhanced implementations of an unlimited field-of-regard BTV concept for low-visibility surface operations were determined to be equivalent in pilot ratings of efficacy and usability.

NASA Columbus Future Forum

NASA Image and Video Library

2012-02-20

Eric Fingerhut, head of Education at Battelle, former chancellor of Ohio's Higher Education System, talks during the during the NASA Future Forum Inspiration and Education Panel at The Ohio State University on Monday, Feb. 20, 2012, in Columbus, Ohio. The NASA Future Forum features panel discussions on the importance of education to our nation's future in space, the benefit of commercialized space technology to our economy and lives here on Earth, and the shifting roles for the public, commercial and international communities in space. Photo Credit: (NASA/Bill Ingalls)

NASA Columbus Future Forum

NASA Image and Video Library

2012-02-20

Founding head of MC2 STEM High School Jeffrey McClellan talks during the NASA Future Forum Inspiration and Education Panel at The Ohio State University on Monday, Feb. 20, 2012, in Columbus, Ohio. The NASA Future Forum features panel discussions on the importance of education to our nation's future in space, the benefit of commercialized space technology to our economy and lives here on Earth, and the shifting roles for the public, commercial and international communities in space. Photo Credit: (NASA/Bill Ingalls)

Lindsey and Boe on forward flight deck

NASA Image and Video Library

2011-02-26

S133-E-006081 (25 Feb. 2011) --- On space shuttle Discovery’s forward flight deck, astronauts Steve Lindsey (right), STS-133 commander, and Eric Boe, pilot, switch seats for a brief procedure as the crew heads toward a weekend docking with the International Space Station. Earlier the crew conducted thorough inspections of the shuttle’s thermal tile system using the Remote Manipulator System/Orbiter Boom Sensor System (RMS/OBSS) and special cameras. Photo credit: NASA or National Aeronautics and Space Administration

Space Station Workshop Commercial Missions and User Requirements: Issues and Recommendations

NASA Technical Reports Server (NTRS)

1988-01-01

The issues and recommendations of a conference on the Space Station are presented. The subjects are organized under three headings of: materials and processing in space, earth and ocean observations, and industrial services. One hundred and two issues and recommendations which resulted from the workskop are categorized for each discipline subpanel. Responses to these issues and recommendations are based on more than twenty interviews with highly qualified NASA personnel and represent the best answers available at this time.

KSC-06pd0242

NASA Image and Video Library

2006-02-08

KENNEDY SPACE CENTER, FLA. - At NASA Kennedy Space Center’s Shuttle Landing Facility, Steve Fossett, seated in the Virgin Atlantic GlobalFlyer cockpit, checks visibility and head space. Fossett will pilot the GlobalFlyer on a record-breaking attempt by flying solo, non-stop without refueling, to surpass the current record for the longest flight of any aircraft. This is the second attempt in two days after a fuel leak was detected Feb. 7. The expected time of takeoff is 7 a.m. Photo credit: NASA/Kim Shiflett

Flight display dynamics and compensatory head movements in pilots.

PubMed

Beer, Jeremy; Freeman, David

2007-06-01

Experiments measured the optokinetic cervical reflex (OKCR), wherein the banking pilot aligns the head with the horizon. In a synthetic cockpit, the flight display was manipulated to test whether changing the visual reference frame would alter OKCR. Eight subjects (five rated pilots) flew a route in simulated visual meteorological conditions that required them to bank the aircraft frequently. Pilots' head tilt was characterized using both the conventional method of regressing against simultaneous aircraft bank, and also an event-based analysis, which identified head movements before, during, and after each turn. Three display configurations were compared to determine whether pilots' orientation would ever migrate from the horizon to the aircraft symbol. The first was a conventional "Inside-Out" condition. A "Frequency-Separated" condition combined Inside-Out horizon geometry with Outside-In dynamics for the aircraft symbol, which depicted joystick bank inputs. In the "Outside-In" condition, the aircraft symbol rolled against a static horizon. Regressions identified an interaction (p < 0.001) between display condition and aircraft bank: head tilt followed horizon tilt in Inside-Out and Frequency-Separated conditions, while remaining mostly level in the Outside-In condition. The event-based analysis identified anticipatory head movements in Inside-Out and Frequency-Separated conditions: 95% CI indicated that before each turn, head tilt favored the direction of the imminent bank. While the conventional analysis confirmed that the horizon comprises a primary spatial reference, the finer-grained event-based analysis indicated that pilots' reference can migrate at least temporarily to the vehicle, and that OKCR can be preceded by anticipatory head movements in the opposite direction.

A Geometric Capacity–Demand Analysis of Maternal Levator Muscle Stretch Required for Vaginal Delivery

PubMed Central

Tracy, Paige V.; DeLancey, John O.; Ashton-Miller, James A.

2016-01-01

Because levator ani (LA) muscle injuries occur in approximately 13% of all vaginal births, insights are needed to better prevent them. In Part I of this paper, we conducted an analysis of the bony and soft tissue factors contributing to the geometric “capacity” of the maternal pelvis and pelvic floor to deliver a fetal head without incurring stretch injury of the maternal soft tissue. In Part II, we quantified the range in demand, represented by the variation in fetal head size and shape, placed on the maternal pelvic floor. In Part III, we analyzed the capacity-to-demand geometric ratio, g, in order to determine whether a mother can deliver a head of given size without stretch injury. The results of a Part I sensitivity analysis showed that initial soft tissue loop length (SL) had the greatest effect on maternal capacity, followed by the length of the soft tissue loop above the inferior pubic rami at ultimate crowning, then subpubic arch angle (SPAA) and head size, and finally the levator origin separation distance. We found the more caudal origin of the puborectal portion of the levator muscle helps to protect it from the stretch injuries commonly observed in the pubovisceral portion. Part II fetal head molding index (MI) and fetal head size revealed fetal head circumference values ranging from 253 to 351 mm, which would increase up to 11 mm upon face presentation. The Part III capacity-demand analysis of g revealed that, based on geometry alone, the 10th percentile maternal capacity predicted injury for all head sizes, the 25th percentile maternal capacity could deliver half of all head sizes, while the 50th percentile maternal capacity could deliver a head of any size without injury. If ultrasound imaging could be operationalized to make measurements of ratio g, it might be used to usefully inform women on their level of risk for levator injury during vaginal birth. PMID:26746116

A Geometric Capacity-Demand Analysis of Maternal Levator Muscle Stretch Required for Vaginal Delivery.

PubMed

Tracy, Paige V; DeLancey, John O; Ashton-Miller, James A

2016-02-01

Because levator ani (LA) muscle injuries occur in approximately 13% of all vaginal births, insights are needed to better prevent them. In Part I of this paper, we conducted an analysis of the bony and soft tissue factors contributing to the geometric "capacity" of the maternal pelvis and pelvic floor to deliver a fetal head without incurring stretch injury of the maternal soft tissue. In Part II, we quantified the range in demand, represented by the variation in fetal head size and shape, placed on the maternal pelvic floor. In Part III, we analyzed the capacity-to-demand geometric ratio, g, in order to determine whether a mother can deliver a head of given size without stretch injury. The results of a Part I sensitivity analysis showed that initial soft tissue loop length (SL) had the greatest effect on maternal capacity, followed by the length of the soft tissue loop above the inferior pubic rami at ultimate crowning, then subpubic arch angle (SPAA) and head size, and finally the levator origin separation distance. We found the more caudal origin of the puborectal portion of the levator muscle helps to protect it from the stretch injuries commonly observed in the pubovisceral portion. Part II fetal head molding index (MI) and fetal head size revealed fetal head circumference values ranging from 253 to 351 mm, which would increase up to 11 mm upon face presentation. The Part III capacity-demand analysis of g revealed that, based on geometry alone, the 10th percentile maternal capacity predicted injury for all head sizes, the 25th percentile maternal capacity could deliver half of all head sizes, while the 50th percentile maternal capacity could deliver a head of any size without injury. If ultrasound imaging could be operationalized to make measurements of ratio g, it might be used to usefully inform women on their level of risk for levator injury during vaginal birth.

Rib forming tool for tubing

DOEpatents

Rowley, James P.; Lewandowski, Edward F.; Groh, Edward F.

1976-01-01

Three cylindrical rollers are rotatably mounted equidistant from the center of a hollow tool head on radii spaced 120.degree. apart. Each roller has a thin flange; the three flanges lie in a single plane to form an internal circumferential rib in a rotating tubular workpiece. The tool head has two complementary parts with two rollers in one part of the head and one roller in the other part; the two parts are joined by a hinge. A second hinge, located so the rollers are between the two hinges, connects one of the parts to a tool bar mounted in a lathe tool holder. The axes of rotation of both hinges and all three rollers are parallel. A hole exposing equal portions of the three roller flanges is located in the center of the tool head. The two hinges permit the tool head to be opened and rotated slightly downward, taking the roller flanges out of the path of the workpiece which is supported on both ends and rotated by the lathe. The parts of the tool head are then closed on the workpiece so that the flanges are applied to the workpiece and form the rib. The tool is then relocated for forming of the next rib.

Semi-automatic 10/20 Identification Method for MRI-Free Probe Placement in Transcranial Brain Mapping Techniques.

PubMed

Xiao, Xiang; Zhu, Hao; Liu, Wei-Jie; Yu, Xiao-Ting; Duan, Lian; Li, Zheng; Zhu, Chao-Zhe

2017-01-01

The International 10/20 system is an important head-surface-based positioning system for transcranial brain mapping techniques, e.g., fNIRS and TMS. As guidance for probe placement, the 10/20 system permits both proper ROI coverage and spatial consistency among multiple subjects and experiments in a MRI-free context. However, the traditional manual approach to the identification of 10/20 landmarks faces problems in reliability and time cost. In this study, we propose a semi-automatic method to address these problems. First, a novel head surface reconstruction algorithm reconstructs head geometry from a set of points uniformly and sparsely sampled on the subject's head. Second, virtual 10/20 landmarks are determined on the reconstructed head surface in computational space. Finally, a visually-guided real-time navigation system guides the experimenter to each of the identified 10/20 landmarks on the physical head of the subject. Compared with the traditional manual approach, our proposed method provides a significant improvement both in reliability and time cost and thus could contribute to improving both the effectiveness and efficiency of 10/20-guided MRI-free probe placement.

Studies of the horizontal vestibulo-ocular reflex on STS 7 and 8

NASA Technical Reports Server (NTRS)

Thornton, William E.; Uri, John J.; Moore, Thomas P.; Pool, Sam L.

1988-01-01

Unpaced voluntary horizontal head oscillation was used to study the Vestibulo-Ocular Reflex (VOR) on Shuttle flights STS 7 and 8. Ten subjects performed head oscillations at 0.33 Hz + or - 30 deg amplitude under the followng conditions: VVOR (visual VOR), eyes open and fixed on a stationary target; VOR-EC, with eyes closed and fixed on the same target in imagination; and VOR-S (VOR suppression), with eyes open and fixed on a head-synchronized target. Effects of weightlessness, flight phase, and Space Motion Sickness (SMS) on head oscillation characteristics were examined. A significant increase in head oscillation frequency was noted inflight in subjects free from SMS. In subjects susceptible to SMS, frequency was reduced during their Symptomatic period. The data also suggest that the amplitude and peak velocity of head oscillation were reduced early inflight. No significant changes were noted in reflex gain or phase in any of the test conditions; however, there was a suggestion of an increase in VVOR and VOR-ES gain early inflight in asymptomatic subjects. A significant difference in VOR-S was found between SMS susceptible and non-susceptible subjects. There is no evidence that any changes in VOR characteristics contributed to SMS.

Effect of visuospatial neglect on spatial navigation and heading after stroke.

PubMed

Aravind, Gayatri; Lamontagne, Anouk

2017-06-09

Visuospatial neglect (VSN) impairs the control of locomotor heading in post-stroke individuals, which may affect their ability to safely avoid moving objects while walking. We aimed to compare VSN+ and VSN- stroke individuals in terms of changes in heading and head orientation in space while avoiding obstacles approaching from different directions and reorienting toward the final target. Stroke participants with VSN (VSN+) and without VSN (VSN-) walked in a virtual environment avoiding obstacles that approached contralesionally, head-on or ipsilesionally. Measures of obstacle avoidance (onset-of-heading change, maximum mediolateral deviation) and target alignment (heading and head-rotation errors with respect to target) were compared across groups and obstacle directions. In total, 26 participants with right-hemisphere stroke participated (13 VSN+ and 13 VSN-; 24 males; mean age 60.3 years, range 48 to 72 years). A larger proportion of VSN+ (75%) than VSN- (38%) participants collided with contralesional and head-on obstacles. For VSN- participants, deviating to the same side as the obstacle was a safe strategy to avoid diagonal obstacles and deviating to the opposite-side led to occasional collisions. VSN+ participants deviated ipsilesionally, displaying same-side and opposite-side strategies for ipsilesional and contralesional obstacles, respectively. Overall, VSN+ participants showed greater distances at onset-of-heading change, smaller maximum mediolateral deviation and larger errors in target alignment as compared with VSN- participants. The ipsilesional bias arising from VSN influences the modulation of heading in response to obstacles and, along with the adoption of the "riskier" strategies, contribute to the higher number colliders and poor goal-directed walking abilities in stroke survivors with VSN. Future research should focus on developing assessment and training tools for complex locomotor tasks such as obstacle avoidance in this population. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Space Shuttle Endeavour Move

NASA Image and Video Library

2012-10-12

The driver of the Over Land Transporter is seen as he maneuvers the space shuttle Endeavour on the streets of Los Angeles as it heads to its new home at the California Science Center, Friday, Oct. 12, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the CSC’s Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers. Photo Credit: (NASA/Bill Ingalls)

Space Shuttle Endeavour Move

NASA Image and Video Library

2012-10-12

The driver of the Over Land Transporter (OLT) is seen as he maneuvers the space shuttle Endeavour on the streets of Los Angeles as it heads to its new home at the California Science Center, Friday, Oct. 12, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the CSC's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers. Photo Credit: (NASA/Carla Cioffi)

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

NASA Technical Reports Server (NTRS)

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

2010-01-01

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

CUSUM analysis of learning curves for the head-mounted microscope in phonomicrosurgery.

PubMed

Chen, Ting; Vamos, Andrew C; Dailey, Seth H; Jiang, Jack J

2016-10-01

To observe the learning curve of the head-mounted microscope in a phonomicrosurgery simulator using cumulative summation (CUSUM) analysis, which incorporates a magnetic phonomicrosurgery instrument tracking system (MPTS). Retrospective case series. Eight subjects (6 medical students and 2 surgeons inexperienced in phonomicrosurgery) operated on phonomicrosurgical simulation cutting tasks while using the head-mounted microscope for 400 minutes total. Two 20-minute sessions occurred each day for 10 total days, with operation quality (Qs ) and completion time (T) being recorded after each session. Cumulative summation analysis of Qs and T was performed by using subjects' performance data from trials completed using a traditional standing microscope as success criteria. The motion parameters from the head-mounted microscope were significantly better than the standing microscope (P < 0.01), but T was longer than that from the standing microscope (P < 0.01). No subject successfully adapted to the head-mounted microscope, as assessed by CUSUM analysis. Cumulative summation analysis can objectively monitor the learning process associated with a phonomicrosurgical simulator system, ultimately providing a tool to assess learning status. Also, motion parameters determined by our MPTS showed that, although the head-mounted microscope provides better motion control, worse Qs and longer T resulted. This decrease in Qs is likely a result of the relatively unstable visual environment that it provides. Overall, the inexperienced surgeons participating in this study failed to adapt to the head-mounted microscope in our simulated phonomicrosurgery environment. 4 Laryngoscope, 126:2295-2300, 2016. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

Evaluation of head orientation and neck muscle EMG signals as three-dimensional command sources.

PubMed

Williams, Matthew R; Kirsch, Robert F

2015-03-05

High cervical spinal cord injuries result in significant functional impairments and affect both the injured individual as well as their family and care givers. To help restore function to these individuals, multiple user interfaces are available to enable command and control of external devices. However, little work has been performed to assess the 3D performance of these interfaces. We investigated the performance of eight human subjects in using three user interfaces (head orientation, EMG from muscles of the head and neck, and a three-axis joystick) to command the endpoint position of a multi-axis robotic arm within a 3D workspace to perform a novel out-to-center 3D Fitts' Law style task. Two of these interfaces (head orientation, EMG from muscles of the head and neck) could realistically be used by individuals with high tetraplegia, while the joystick was evaluated as a standard of high performance. Performance metrics were developed to assess the aspects of command source performance. Data were analyzed using a mixed model design ANOVA. Fixed effects were investigated between sources as well as for interactions between index of difficulty, command source, and the five performance measures used. A 5% threshold for statistical significance was used in the analysis. The performances of the three command interfaces were rather similar, though significant differences between command sources were observed. The apparent similarity is due in large part to the sequential command strategy (i.e., one dimension of movement at a time) typically adopted by the subjects. EMG-based commands were particularly pulsatile in nature. The use of sequential commands had a significant impact on each command source's performance for movements in two or three dimensions. While the sequential nature of the commands produced by the user did not fit with Fitts' Law, the other performance measures used were able to illustrate the properties of each command source. Though pulsatile, given the overall similarity between head orientation and the EMG interface, (which also could be readily included in a future implanted neuroprosthesis) the use of EMG as a command source for controlling an arm in 3D space is an attractive choice.

76 FR 42712 - Advisory Committee on Head Start Research and Evaluation

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-19

... Research and Evaluation will provide feedback on the published final report for the Head Start Impact Study... recommendations on follow-up research, including additional analysis of the Head Start Impact Study data. The... research agenda, including--but not limited to--how the Head Start Impact Study fits within this agenda...

Ceramic Heads Decrease Metal Release Caused by Head-taper Fretting and Corrosion.

PubMed

Kocagoz, Sevi B; Underwood, Richard J; MacDonald, Daniel W; Gilbert, Jeremy L; Kurtz, Steven M

2016-04-01

Metal release resulting from taper fretting and corrosion is a clinical concern, because wear and corrosion products may stimulate adverse local tissue reactions. Unimodular hip arthroplasties have a conical taper between the femoral head (head bore taper) and the femoral stem (stem cone taper). The use of ceramic heads has been suggested as a way of reducing the generation of wear and corrosion products from the head bore/stem cone taper junction. A previous semiquantitative study found that ceramic heads had less visual evidence of fretting-corrosion damage compared with CoCr heads; but, to our knowledge, no studies have quantified the volumetric material loss from the head bore and stem cone tapers of a matched cohort of ceramic and metal heads. We asked: (1) Do ceramic heads result in less volume of material loss at the head-stem junction compared with CoCr heads; (2) do stem cone tapers have less volumetric material loss compared with CoCr head bore tapers; (3) do visual fretting-corrosion scores correlate with volumetric material loss; and (4) are device, patient, or intraoperative factors associated with volumetric material loss? A quantitative method was developed to estimate volumetric material loss from the head and stem taper in previously matched cohorts of 50 ceramic and 50 CoCr head-stem pairs retrieved during revision surgery for causes not related to adverse reactions to metal particles. The cohorts were matched according to (1) implantation time, (2) stem flexural rigidity, and (3) lateral offset. Fretting corrosion was assessed visually using a previously published four-point, semiquantitative scoring system. The volumetric loss was measured using a precision roundness machine. Using 24 equally spaced axial traces, the volumetric loss was estimated using a linear least squares fit to interpolate the as-manufactured surfaces. The results of this analysis were considered in the context of device (taper angle clearance, head size, head offset, lateral offset, stem material, and stem surface finish) and patient factors that were obtained from the patients' operative records (implantation time, age at insertion, activity level, and BMI). The cumulative volumetric material losses estimated for the ceramic cohort had a median of 0.0 mm(3) per year (range, 0.0-0.4 mm(3)). The cumulative volumetric material losses estimated for the CoCr cohort had a median of 0.1 mm(3) per year (range, 0.0-8.8 mm(3)). An order of magnitude reduction in volumetric material loss was found when a ceramic head was used instead of a CoCr head (p < 0.0001). In the CoCr cohort, the femoral head bore tapers had a median material loss of 0.02 mm(3) (range, 0.0-8.7 mm(3)) and the stem cone tapers had a median material loss of 0.0 mm(3) (range, 0.0-0.32 mm(3)/year). There was greater material loss from femoral head bore tapers compared with stem cone tapers in the CoCr cohort (p < 0.001). There was a positive correlation between visual scoring and volumetric material loss (Spearman's ρ = 0.67, p < 0.01). Although visual scoring was effective for preliminary screening to separate tapers with no or mild damage from tapers with moderate to severe damage, it was not capable of discriminating in the large range of material loss observed at the taper surfaces with moderate to severe fretting-corrosion damage, indicated with a score of 3 or 4. We observed no correlations between volumetric material loss and device and patient factors. The majority of estimated material loss from the head bore-stem cone junctions resulting from taper fretting and corrosion was from the CoCr head bore tapers as opposed to the stem cone tapers. Additionally, the total material loss from the ceramic cohort showed a reduction in the amount of metal released by an order of magnitude compared with the CoCr cohort. We found that ceramic femoral heads may be an effective means by which to reduce metal release caused by taper fretting and corrosion at the head bore-stem cone modular interface in THAs.

Video analysis of blows to the head and face at the 1999 World Taekwondo Championships.

PubMed

Koh, J O; Watkinson, E J

2002-09-01

Limited research has been done on head blows that may result in mild traumatic brain injury in Taekwondo. The purpose of this study was to investigate the fighting conditions under which blows to the head commonly take place, with a view to determining the typical conditions under which injury may occur. videotape analysis (retrospective). the semi-final and final matches (a total of 48 matches) at the 14th World Taekwondo Championships in 1999. 64 athletes (32 females and 32 males) who won elimination-round matches (out of 563 competitors), aged 15 to 38 years. frequency, mechanism of head blows, characteristics of situations leading up to and following head blows, frequency of multiple impacts. A total of 35 incidents of head blow occurred (365 blows per 1,000 athlete exposures). All of these head blows were associated with a direct head or face contact and frequently involved: a closed sparring stance, shorter athletes, axe or roundhouse type kicks, attacker's offensive kick, and head-blow-receiver's offensive action with absence of a blocking skill. To prevent possible brain injury resulting from direct head blows, updated safety education, a complete understanding of concussion for athletes, coaches, and referees, and a rule change in competition Taekwondo are recommended.

Head Position Comparison between Students with Normal Hearing and Students with Sensorineural Hearing Loss.

PubMed

Melo, Renato de Souza; Amorim da Silva, Polyanna Waleska; Souza, Robson Arruda; Raposo, Maria Cristina Falcão; Ferraz, Karla Mônica

2013-10-01

Introduction Head sense position is coordinated by sensory activity of the vestibular system, located in the inner ear. Children with sensorineural hearing loss may show changes in the vestibular system as a result of injury to the inner ear, which can alter the sense of head position in this population. Aim Analyze the head alignment in students with normal hearing and students with sensorineural hearing loss and compare the data between groups. Methods This prospective cross-sectional study examined the head alignment of 96 students, 48 with normal hearing and 48 with sensorineural hearing loss, aged between 7 and 18 years. The analysis of head alignment occurred through postural assessment performed according to the criteria proposed by Kendall et al. For data analysis we used the chi-square test or Fisher exact test. Results The students with hearing loss had a higher occurrence of changes in the alignment of the head than normally hearing students (p < 0.001). Forward head posture was the type of postural change observed most, occurring in greater proportion in children with hearing loss (p < 0.001), followed by the side slope head posture (p < 0.001). Conclusion Children with sensorineural hearing loss showed more changes in the head posture compared with children with normal hearing.

Head Position Comparison between Students with Normal Hearing and Students with Sensorineural Hearing Loss

PubMed Central

Melo, Renato de Souza; Amorim da Silva, Polyanna Waleska; Souza, Robson Arruda; Raposo, Maria Cristina Falcão; Ferraz, Karla Mônica

2013-01-01

Introduction Head sense position is coordinated by sensory activity of the vestibular system, located in the inner ear. Children with sensorineural hearing loss may show changes in the vestibular system as a result of injury to the inner ear, which can alter the sense of head position in this population. Aim Analyze the head alignment in students with normal hearing and students with sensorineural hearing loss and compare the data between groups. Methods This prospective cross-sectional study examined the head alignment of 96 students, 48 with normal hearing and 48 with sensorineural hearing loss, aged between 7 and 18 years. The analysis of head alignment occurred through postural assessment performed according to the criteria proposed by Kendall et al. For data analysis we used the chi-square test or Fisher exact test. Results The students with hearing loss had a higher occurrence of changes in the alignment of the head than normally hearing students (p < 0.001). Forward head posture was the type of postural change observed most, occurring in greater proportion in children with hearing loss (p < 0.001), followed by the side slope head posture (p < 0.001). Conclusion Children with sensorineural hearing loss showed more changes in the head posture compared with children with normal hearing. PMID:25992037

46 CFR 72.01-25 - Additional structural requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... inner skins shall be tested with water to-a-head corresponding to the requirements of paragraph (a)(1) of this section upon completion of construction. (6) The watertight space enclosing the stern tube...

46 CFR 72.01-25 - Additional structural requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... inner skins shall be tested with water to-a-head corresponding to the requirements of paragraph (a)(1) of this section upon completion of construction. (6) The watertight space enclosing the stern tube...

46 CFR 72.01-25 - Additional structural requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... inner skins shall be tested with water to-a-head corresponding to the requirements of paragraph (a)(1) of this section upon completion of construction. (6) The watertight space enclosing the stern tube...

46 CFR 72.01-25 - Additional structural requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... inner skins shall be tested with water to-a-head corresponding to the requirements of paragraph (a)(1) of this section upon completion of construction. (6) The watertight space enclosing the stern tube...

Exercise Within LBNP to Produce Artificial Gravity

NASA Technical Reports Server (NTRS)

Hargens, Alan R.

1996-01-01

Integrated physiologic countermeasures are needed to maintain orthostatic tolerance after spaceflight or bed rest. We hypothesized that supine exercise during LBNP would prevent bed rest-induced loss of orthostatic tolerance by preventing hemoconcentration. In a study conducted jointly with NASA Johnson Space Center and the University of Texas Medical Branch, Galveston, TX, fifteen male subjects underwent 5 days of 6 deg head-down bed rest: 5 control subjects did not exercise, and 10 performed 30 min/day of supine interval treadmill exercise at intensities up to 90% VO(sub 2peak). We will undertake two 14 day bed-rest studies (6 deg head-down tilt bed rest, HDT) to investigate the mechanism of action and efficacy of our partial vacuum exerciser concept. These 14 day bed rest studies were chosen to simulate current microgravity exposures for Space Shuttle crew members.

A comprehensive Guyton model analysis of physiologic responses to preadapting the blood volume as a countermeasure to fluid shifts

NASA Technical Reports Server (NTRS)

Simanonok, K. E.; Srinivasan, R. S.; Myrick, E. E.; Blomkalns, A. L.; Charles, J. B.

1994-01-01

The Guyton model of fluid, electrolyte, and circulatory regulation is an extensive mathematical model capable of simulating a variety of experimental conditions. It has been modified for use at NASA to simulate head-down tilt, a frequently used analog of weightlessness. Weightlessness causes a headward shift of body fluids that is believed to expand central blood volume, triggering a series of physiologic responses resulting in large losses of body fluids. We used the modified Guyton model to test the hypothesis that preadaptation of the blood volume before weightless exposure could counteract the central volume expansion caused by fluid shifts, and thereby attenuate the circulatory and renal responses that result in body fluid losses. Simulation results show that circulatory preadaptation, by a procedure resembling blood donation immediately before head-down bedrest, is effective in damping the physiologic responses to fluid shifts and reducing body fluid losses. After 10 hours of head-down tilt, preadaptation also produces higher blood volume, extracellular volume, and total body water for 20 to 30 days of bedrest, compared with non-preadapted control. These results indicate that circulatory preadaptation before current Space Shuttle missions may be beneficial for the maintenance of reentry and postflight orthostatic tolerance in astronauts. This paper presents a comprehensive examination of the simulation results pertaining to changes in relevant physiologic variables produced by blood volume reduction before a prolonged head-down tilt. The objectives were to study and develop the countermeasure theoretically, to aid in planning experimental studies of the countermeasure, and to identify potentially disadvantageous physiologic responses that may be caused by the countermeasure.

The Effect of Rivet Heads on the Characteristics of a 6 by 36 Foot Clark Y Metal Airfoil

NASA Technical Reports Server (NTRS)

Dearborn, Clinton H

1933-01-01

An investigation was conducted in the N.A.C.A. full-scale wind tunnel to determine the effects of exposed rivet heads on the aerodynamic characteristics of a metal-covered 6 by 36 foot Clasky airfoil. Lead punching simulating 1/8inch rivet heads were attached in full-span rows at a pitch of 1 inch at various chord positions. Tests were made at velocities varying from 40 to 120 miles per hour to investigate the scale effect. Rivets at the 5 percent chord position the upper surface of the airfoil produced the greatest increase in drag for a single row. Nine rows of rivets on both surfaces, simulating rivet spacing of multispan construction, increased the drag coefficients by a constant amount at velocities between 100 and 120 miles per hour. Accordingly, if rivets spaced the same as those on the test airfoil were used on a Clark Y wing of 300 square feet area and operated at 200 miles per hour, the drag would be increased over that for the smooth wing by 55 pounds and the power required would be increased by 29 horsepower.

'Witch Head' Brews Baby Stars

NASA Image and Video Library

2017-12-08

A witch appears to be screaming out into space in this new image from NASA's Wide-Field Infrared Survey Explorer, or WISE. The infrared portrait shows the Witch Head nebula, named after its resemblance to the profile of a wicked witch. Astronomers say the billowy clouds of the nebula, where baby stars are brewing, are being lit up by massive stars. Dust in the cloud is being hit with starlight, causing it to glow with infrared light, which was picked up by WISE's detectors. The Witch Head nebula is estimated to be hundreds of light-years away in the Orion constellation, just off the famous hunter's knee. WISE was recently "awakened" to hunt for asteroids in a program called NEOWISE. The reactivation came after the spacecraft was put into hibernation in 2011, when it completed two full scans of the sky, as planned. Image credit: NASA/JPL-Caltech NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Simulation of interaction between ground water in an alluvial aquifer and surface water in a large braided river

USGS Publications Warehouse

Leake, S.A.; Lilly, M.R.

1995-01-01

The Fairbanks, Alaska, area has many contaminated sites in a shallow alluvial aquifer. A ground-water flow model is being developed using the MODFLOW finite-difference ground-water flow model program with the River Package. The modeled area is discretized in the horizontal dimensions into 118 rows and 158 columns of approximately 150-meter square cells. The fine grid spacing has the advantage of providing needed detail at the contaminated sites and surface-water features that bound the aquifer. However, the fine spacing of cells adds difficulty to simulating interaction between the aquifer and the large, braided Tanana River. In particular, the assignment of a river head is difficult if cells are much smaller than the river width. This was solved by developing a procedure for interpolating and extrapolating river head using a river distance function. Another problem is that future transient simulations would require excessive numbers of input records using the current version of the River Package. The proposed solution to this problem is to modify the River Package to linearly interpolate river head for time steps within each stress period, thereby reducing the number of stress periods required.

Improvement of absolute positioning of precision stage based on cooperation the zero position pulse signal and incremental displacement signal

NASA Astrophysics Data System (ADS)

Wang, H. H.; Shi, Y. P.; Li, X. H.; Ni, K.; Zhou, Q.; Wang, X. H.

2018-03-01

In this paper, a scheme to measure the position of precision stages, with a high precision, is presented. The encoder is composed of a scale grating and a compact two-probe reading head, to read the zero position pulse signal and continuous incremental displacement signal. The scale grating contains different codes, multiple reference codes with different spacing superimposed onto the incremental grooves with an equal spacing structure. The codes of reference mask in the reading head is the same with the reference codes on the scale grating, and generate pulse signal to locate the reference position primarily when the reading head moves along the scale grating. After locating the reference position in a section by means of the pulse signal, the reference position can be located precisely with the amplitude of the incremental displacement signal. A kind of reference codes and scale grating were designed, and experimental results show that the primary precision of the design achieved is 1 μ m. The period of the incremental signal is 1μ m, and 1000/N nm precision can be achieved by subdivide the incremental signal in N times.

KSC-06pd1415

NASA Image and Video Library

2006-07-04

KENNEDY SPACE CENTER, FLA. - In Firing Room 4 of the Launch Control Center, Kennedy Space Center Director Jim Kennedy watches one of the computer screens as the countdown heads for launch of Space Shuttle Discovery on mission STS-121. Liftoff was on-time at 2:38 p.m. EDT. During the 12-day mission, the STS-121 crew of seven will test new equipment and procedures to improve shuttle safety, as well as deliver supplies and make repairs to the International Space Station. Landing is scheduled for July 16 or 17 at Kennedy's Shuttle Landing Facility. Photo credit: NASA/Kim Shiflett

Head movement compensation in real-time magnetoencephalographic recordings.

PubMed

Little, Graham; Boe, Shaun; Bardouille, Timothy

2014-01-01

Neurofeedback- and brain-computer interface (BCI)-based interventions can be implemented using real-time analysis of magnetoencephalographic (MEG) recordings. Head movement during MEG recordings, however, can lead to inaccurate estimates of brain activity, reducing the efficacy of the intervention. Most real-time applications in MEG have utilized analyses that do not correct for head movement. Effective means of correcting for head movement are needed to optimize the use of MEG in such applications. Here we provide preliminary validation of a novel analysis technique, real-time source estimation (rtSE), that measures head movement and generates corrected current source time course estimates in real-time. rtSE was applied while recording a calibrated phantom to determine phantom position localization accuracy and source amplitude estimation accuracy under stationary and moving conditions. Results were compared to off-line analysis methods to assess validity of the rtSE technique. The rtSE method allowed for accurate estimation of current source activity at the source-level in real-time, and accounted for movement of the source due to changes in phantom position. The rtSE technique requires modifications and specialized analysis of the following MEG work flow steps.•Data acquisition•Head position estimation•Source localization•Real-time source estimation This work explains the technical details and validates each of these steps.

Chromaticity effects on head-tail instabilities for broadband impedance using two particle model, Vlasov analysis, and simulations

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

Chin, Yong Ho; Chao, Alexander Wu; Blaskiewicz, Michael M.

Effects of the chromaticity on head-tail instabilities for broadband impedances are comprehensively studied, using the two particle model, the Vlasov analysis and computer simulations. We show both in the two particle model and the Vlasov analysis with the trapezoidal (semiconstant) wake model that we can derive universal contour plots for the growth factor as a function of the two dimensionless parameters: the wakefield strength, Υ, and the difference of the betatron phase advances between the head and the tail, χ. They reveal how the chromaticity affects strong head-tail instabilities and excites head-tail instabilities. We also apply the LEP (Large Electron-Positronmore » Collider) broadband resonator model to the Vlasov approach and find that the results are in very good agreement with those of the trapezoidal wake model. The theoretical findings are also reinforced by the simulation results. In conclusion, the trapezoidal wake model turns out to be a very useful tool since it significantly simplifies the time domain analysis and provides well-behaved impedance at the same time.« less

Chromaticity effects on head-tail instabilities for broadband impedance using two particle model, Vlasov analysis, and simulations

DOE PAGES

Chin, Yong Ho; Chao, Alexander Wu; Blaskiewicz, Michael M.; ...

2017-07-28

Effects of the chromaticity on head-tail instabilities for broadband impedances are comprehensively studied, using the two particle model, the Vlasov analysis and computer simulations. We show both in the two particle model and the Vlasov analysis with the trapezoidal (semiconstant) wake model that we can derive universal contour plots for the growth factor as a function of the two dimensionless parameters: the wakefield strength, Υ, and the difference of the betatron phase advances between the head and the tail, χ. They reveal how the chromaticity affects strong head-tail instabilities and excites head-tail instabilities. We also apply the LEP (Large Electron-Positronmore » Collider) broadband resonator model to the Vlasov approach and find that the results are in very good agreement with those of the trapezoidal wake model. The theoretical findings are also reinforced by the simulation results. In conclusion, the trapezoidal wake model turns out to be a very useful tool since it significantly simplifies the time domain analysis and provides well-behaved impedance at the same time.« less

COIS, Favier works with experiment assisted by Helms during LMS-1 mission

NASA Image and Video Library

1996-07-09

STS078-398-032 (20 June - 7 July 1996) --- Astronaut Susan J. Helms, payload commander, measures the distance between Jean-Jacques Favier’s head and the luminous torque, used for the Canal and Otolith Interaction Study (COIS) on the Life and Microgravity Spacelab (LMS-1) mission. Favier, representing the French Space Agency (CNES), is one of two international payload specialists on the almost-17-day flight. This view shows the Voluntary Head Movement (VHM) segment of the experiment. The VHM is meant to characterize how the coordination of head and eye movement changes as a result of spaceflight. Since most vestibular functions are influenced by gravity, the COIS experiment is meant to measure response differences in microgravity.

Liftoff of STS-62 Space Shuttle Columbia

NASA Image and Video Library

1994-03-04

STS062-S-053 (4 March 1994) --- Carrying a crew of five veteran NASA astronauts and the United States Microgravity Payload (USMP), the Space Shuttle Columbia heads toward its sixteenth mission in Earth-orbit. Launch occurred at 8:53 a.m. (EST), March 4, 1994. Onboard were astronauts John H. Casper, Andrew M. Allen, Marsha S. Ivins, Charles D. (Sam) Gemar and Pierre J. Thuot.