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Sample records for sagittal coronal planes

  1. Sagittal plane biomechanics. American Diabetes Association.

    PubMed

    Dananberg, H J

    2000-01-01

    During walking, the center of body mass must pass from behind the weightbearing foot to in front of it. For this to take place, the foot must function as a sagittal plane pivot. Because the range required for this motion is approximately five times as great as both frontal and transverse plane motion, its evaluation should become an essential part of a podiatric biomechanical assessment. Lack of proper sagittal plane motion and its sequelae are described. PMID:10659532

  2. Intrinsic and Extrinsic Contributions to Seated Balance in the Sagittal and Coronal Planes: Implications for Trunk Control After Spinal Cord Injury

    PubMed Central

    Audu, Musa L.; Triolo, Ronald J.

    2016-01-01

    The contributions of intrinsic (passive) and extrinsic (active) properties of the human trunk, in terms of the simultaneous actions about the hip and spinal joints, to the control of sagittal and coronal seated balance were examined. Able-bodied (ABD) and spinal-cord-injured (SCI) volunteers sat on a moving platform which underwent small amplitude perturbations in the anterior-posterior (AP) and medial-lateral (ML) directions while changes to trunk orientation were measured. A linear parametric model that related platform movement to trunk angle was fit to the experimental data by identifying model parameters in the time domain. The results showed that spinal cord injury leads to a systematic reduction in the extrinsic characteristics, while most of the intrinsic characteristics were rarely affected. In both SCI and ABD individuals, passive characteristics alone were not enough to maintain seated balance. Passive stiffness in the ML direction was almost 3 times that in the AP direction, making more extrinsic mechanisms necessary for balance in the latter direction. Proportional and derivative terms of the extrinsic model made the largest contribution to the overall output from the active system, implying that a simple proportional plus derivative (PD) controller structure will suffice for restoring seated balance after spinal cord injury. PMID:25780873

  3. High-resolution sagittal and coronal reformatted CT images of the larynx

    SciTech Connect

    Silverman, P.M.; Johnson, G.A.; Korobkin, M.

    1983-04-01

    Computed tomography has become the major technique for evaluation of patients with laryngeal corcinoma and trauma to the larynx. The routine examination usually consists of 5 mm contiguous selection through the larynx in quiet respiration. Reformatted images obtained from these sections have not been of clinical value, in part because of the poor resolution of these images. In the past, thin-section scanning (1.5 mm collimation) has been impractical because of the significant time required to scan the entire larynx. By using the technique of rapid sequential scanning with automated table incrementation this logistic difficulty can be overcome, and the total thin-section examination may be performed in less than 9 min. Sophisticated computer software allows rapid reformatting of transaxial images in sagittal and coronal planes. This report illustates the normal and abnormal appearance of the larynx on coronal and sagittal reformatted images and compares reformatted images using the routine technique to those using the thin-section technique.

  4. Percutaneous sagittal plane closing wedge osteotomy of the first metatarsal.

    PubMed

    Lui, Tun Hing

    2014-02-01

    Osteotomy of the first metatarsal in the sagittal plane is useful in correction of numerous deformity of the foot. Plantarflexion osteotomy of the first metatarsal can be used to treat hallux rigidus, hallux limitus, forefoot varus in flatfoot deformity and iatrogenic metatarsus primus elevates. Dorsiflexion osteotomy of the first metatarsal is an important component in surgical correction of pes cavus. It is also indicated in recalcitrant diabetic neuropathic ulcers at the first metatarsal head. We described a minimally invasive technique of sagittal plane corrective osteotomy of the first metatarsal, which can be either a plantarflexion or dorsiflexion one. PMID:23412315

  5. Unilateral coronal synostosis: can we trust the sagittal suture as a landmark for the underlying superior sagittal sinus?

    PubMed

    Protzenko Cervante, Tatiana; Arnaud, Eric; Brunelle, Francis; Di Rocco, Federico

    2016-05-01

    OBJECTIVE The sagittal suture is usually considered an external anatomical landmark, indicating the location of the superior sagittal sinus (SSS) for surgical approaches. Children with unilateral coronal synostosis (UCS) often present with an important deviation of the sagittal suture. Because these patients usually undergo frontal reconstruction or even endoscope-assisted minimally invasive procedures, it is imperative to know the location of the SSS. The aim of this investigation was to study the anatomical relationship between the SSS and the sagittal suture in children with anterior plagiocephaly. METHODS The authors retrospectively studied the relationship between the sagittal sinus and the sagittal suture at 5 points: nasion, midpoint nasion-bregma, bregma, midpoint bregma-lambda, and lambda. The study analyzed CT scans of 50 children with UCS admitted to the craniofacial unit of Necker Enfants Malades Hospital between March 2006 and March 2013 and compared them with 50 control children with no evidence of craniosynostosis, bone disease, or genetic syndromes. The authors also analyzed the presence of extracerebral fluid collection and ventricular asymmetry in children with UCS. RESULTS Fifty-six percent of patients had anterior right UCS and 44% had left-sided UCS. Type I UCS was seen in 1 patient, Type IIA in 20 patients, Type IIB in 20 patients, and Type III in 9 patients. The authors found that the nasion is usually deviated to the ipsilateral side of the synostosis, the bregma contralaterally, and the lambda ipsilaterally. The gap distances between the reference point and the SSS were 0-7.3 mm (mean 1.4 mm) at the nasion; 0-16.7 mm (mean 3.8 mm) at the midpoint nasion-bregma; 0-12 mm (mean 5.8 mm) at the bregma; 0-9.5 mm (mean 3 mm) at the midpoint bregma-lambda; and 0-11.6 mm (mean 5.5 mm) at the lambda. Conversely, a discrepancy of more than 1 mm between the SSS and the position of the suture was found only in 7 control cases (14%). Of patients with UCS

  6. SAGITTAL PLANE KINEMATICS OF THE ADULT HYOID BONE

    PubMed Central

    Zheng, Liying; Jahn, Jessica; Vasavada, Anita N.

    2012-01-01

    The hyoid bone is a unique bone in the skeleton not articulated to any other bone. The hyoid muscles, which attach to the hyoid bone, may play a role in neck mechanics, but analysis of their function requires quantifying hyoid bone mechanics. The goal of this study was to obtain the detailed kinematics of the hyoid bone over a large range of flexion-extension motion using radiographs at 5 postures. The position of the hyoid bone in the sagittal plane was characterized with respect to head, jaw and vertebral movements. Sex differences in hyoid kinematics were also investigated. We hypothesized that (1) the position of the hyoid bone in the sagittal plane is linearly correlated with motion of the head, jaw and vertebrae, and (2) the hyoid position, size and kinematics are sex-specific. We found that the hyoid bone X, Y and angular position generally had strong linear correlations with the positions of the head, jaw and the cervical vertebrae C1–C4. Hyoid X and angular position was also correlated to C5. Sex differences were found in some regressions of the hyoid bone with respect to C1–C5. The angular and linear measurements of the hyoid bone showed sex differences in absolute values, which were not evident after normalization by posture or neck size. Incorporating these results to neck models would enable accurate modeling of the hyoid muscles. This may have implications for analyzing the mechanics of the cervical spine, including loads on neck structures and implants. PMID:22176712

  7. Human foot placement and balance in the sagittal plane.

    PubMed

    Millard, Matthew; Wight, Derek; McPhee, John; Kubica, Eric; Wang, David

    2009-12-01

    Foot placement has long been recognized as the primary mechanism that humans use to restore balance. Many biomechanists have examined where humans place their feet during gait, perturbations, and athletic events. Roboticists have also used foot placement as a means of control but with limited success. Recently, Wight et al. (2008, "Introduction of the Foot Placement Estimator: A Dynamic Measure of Balance for Bipedal Robotics," ASME J. Comput. Nonlinear Dyn., 3, p. 011009) introduced a planar foot placement estimator (FPE) algorithm that will restore balance to a simplified biped that is falling. This study tested the FPE as a candidate function for sagittal plane human-foot-placement (HFP) by recording the kinematics of 14 healthy subjects while they performed ten walking trials at three speeds. The FPE was highly correlated with HFP (rho>or=0.997) and its accuracy varied linearly from 2.6 cm to -8.3 cm as walking speed increased. A sensitivity analysis revealed that assumption violations of the FPE cannot account for the velocity-dependent changes in FPE-HFP error suggesting that this behavior is volitional. PMID:20524724

  8. THE RELATIONSHIP BETWEEN LOWER EXTREMITY CLOSED KINETIC CHAIN STRENGTH & SAGITTAL PLANE LANDING KINEMATICS IN FEMALE ATHLETES

    PubMed Central

    Kivlan, Ben; Scibek, Jason S.

    2011-01-01

    Background: Female athletes continue to injure their anterior cruciate ligaments at a greater rate than males in comparable sports. During landing activities, females exhibit several different kinematic and kinetic traits when compared to their male counterparts including decreased knee flexion angles as well as decreased lower extremity (LE) strength. While open kinetic chain strength measures have not been related to landing kinematics, given the closer replication of movement patterns that occur during closed kinetic chain (CKC) activity, it is possible that lower extremity strength if measured in this fashion will be related to landing kinematics. Purpose: To determine if unilateral isometric CKC lower extremity (LE) strength was related to sagittal plane tibiofemoral kinematics during a single leg landing task in competitive female athletes. We hypothesized females who demonstrated lesser CKC LE strength would exhibit decreased sagittal plane angles during landing. Methods: 20 competitive female athletes (age = 16.0 ± 1.8 yrs; height = 166.5 ± 8.3 cm; weight = 59.7 ± 10.2 kg) completed CKC LE strength testing followed by 5 unilateral drop landings on the dominant LE during one test session at an outpatient physical therapy clinic. Closed kinetic chain LE strength was measured on a computerized leg press with an integrated load cell while sagittal plane tibiofemoral kinematics were quantified with an electrogoniometer. Results: No significant relationships between absolute or normalized isometric CKC strength and sagittal plane landing kinematics were identified. Conclusions: Closed kinetic chain lower extremity isometric strength tested at 25 degrees of knee flexion is not related to sagittal plane landing kinematics in adolescent competitive female athletes. Levels of Evidence: Analytic, Observational PMID:21655453

  9. Automatic extraction of the mid-sagittal plane using an ICP variant

    NASA Astrophysics Data System (ADS)

    Fieten, Lorenz; Eschweiler, Jörg; de la Fuente, Matías; Gravius, Sascha; Radermacher, Klaus

    2008-03-01

    Precise knowledge of the mid-sagittal plane is important for the assessment and correction of several deformities. Furthermore, the mid-sagittal plane can be used for the definition of standardized coordinate systems such as pelvis or skull coordinate systems. A popular approach for mid-sagittal plane computation is based on the selection of anatomical landmarks located either directly on the plane or symmetrically to it. However, the manual selection of landmarks is a tedious, time-consuming and error-prone task, which requires great care. In order to overcome this drawback, previously it was suggested to use the iterative closest point (ICP) algorithm: After an initial mirroring of the data points on a default mirror plane, the mirrored data points should be registered iteratively to the model points using rigid transforms. Finally, a reflection transform approximating the cumulative transform could be extracted. In this work, we present an ICP variant for the iterative optimization of the reflection parameters. It is based on a closed-form solution to the least-squares problem of matching data points to model points using a reflection. In experiments on CT pelvis and skull datasets our method showed a better ability to match homologous areas.

  10. Assessment of methods to extract the mid-sagittal plane from brain MR images

    NASA Astrophysics Data System (ADS)

    Kuijf, Hugo J.; Leemans, Alexander; Viergever, Max A.; Vincken, Koen L.

    2013-03-01

    Automatic detection of the mid-sagittal plane, separating both hemispheres of the brain, is useful in various applications. Several methods have been developed in the past years, applying different techniques to estimate the position of the mid-sagittal plane. These methods can be classified into three distinct classes: feature-based, global symmetry based, and local symmetry based methods. Feature-based methods use the shape or intensity of the interhemispheric fissure to extract the mid-sagittal plane. Global symmetry based methods reflect the entire image with respect to the sagittal axes and perform a rigid registration. Local symmetry based methods try to optimize a symmetry-measure in a small band covering the interhemispheric fissure. From each class, one leading method has been implemented. The methods have been evaluated on the same datasets to allow a fair comparison. Manual delineations were made by two experienced human observers. The results show that the examined methods perform similar to human observers. No significant differences were found between errors (defined as the angle and volume between planes) made by the methods and the inter-observer differences. Feature-based and local symmetry based methods have a low computation time of 1.8 and 0.5 seconds, respectively. The global symmetry based method has a higher computation time of 33.6 seconds, caused by the full 3D rigid registration. The largest errors, both by the methods and observers, are made in participants with cerebral atrophy. These participants have a widened interhemispheric fissure, allowing many plane orientations and positions to result in a valid division of the hemispheres.

  11. Sagittal plane compensations for artificially induced limitation of the first metatarsophalangeal joint: a preliminary study.

    PubMed

    Hall, Christine; Nester, Christopher J

    2004-01-01

    This study was undertaken to establish whether reduced dorsiflexion at the first metatarsophalangeal joint affects sagittal plane kinematics at the ankle, knee, and hip. Twenty individuals with symptom-free metatarsophalangeal joints were studied as they walked with and without an insole designed to restrict first metatarsophalangeal joint dorsiflexion. Sagittal plane kinematics at the ankle, knee, and hip were compared in the two conditions. When walking with the insole, the ankle was more dorsiflexed during late midstance and less plantarflexed during propulsion, the knee was more flexed during midstance, and the hip was less extended during late midstance. This evidence of a link between the first metatarsophalangeal joint and the kinematics of the proximal joints demonstrates the potential for the clinical entities of hallux rigidus and hallux limitus to influence gait and justifies more detailed study of this relationship. PMID:15153589

  12. Ipsilateral wrist-ankle movements in the sagittal plane encoded in extrinsic reference frame.

    PubMed

    Muraoka, Tetsuro; Ishida, Yuki; Obu, Takashi; Crawshaw, Larry; Kanosue, Kazuyuki

    2013-04-01

    When performing oscillatory movements of two joints in the sagittal plane, there is a directional constraint for performing such movements. Previous studies could not distinguish whether the directional constraint reflected movement direction encoded in the extrinsic (outside the body) reference frame or in the intrinsic (the participants' torso/head) reference frame since participants performed coordinated movements in a sitting position where the torso/head was stationary relative to the external world. In order to discern the reference frame in the present study, participants performed paced oscillatory movements of the ipsilateral wrist and ankle in the sagittal plane in a standing position so that the torso/head moved relative to the external world. The coordinated movements were performed in one of two modes of coordination, moving the hand upward concomitant with either ankle plantarflexion or ankle dorsiflexion. The same directional mode relative to extrinsic space was more stable and accurate as compared with the opposite directional mode. When forearm position was changed from the pronated position to the supinated position, similar results were obtained, indicating that the results were independent of a particular coupling of muscles. These findings suggest that the directional constraint on ipsilateral joints movements in the sagittal plane reflects movement direction encoded in the extrinsic reference frame. PMID:23507257

  13. Biomechanical Comparison of Single- and Double-Leg Jump Landings in the Sagittal and Frontal Plane

    PubMed Central

    Taylor, Jeffrey B.; Ford, Kevin R.; Nguyen, Anh-Dung; Shultz, Sandra J.

    2016-01-01

    Background: Double-leg forward or drop-jump landing activities are typically used to screen for high-risk movement strategies and to determine the success of neuromuscular injury prevention programs. However, research suggests that these tasks that occur primarily in the sagittal plane may not adequately represent the lower extremity biomechanics that occur during unilateral foot contact or non–sagittal plane movements that are characteristic of many multidirectional sports. Purpose: To examine the extent to which lower extremity biomechanics measured during a jump landing on a double leg (DL) after a sagittal plane (SAG) movement is representative of biomechanics measured during single-leg (SL) or frontal plane (FRONT) jump landing tasks. Study Design: Controlled laboratory study. Methods: Lower extremity biomechanics were measured in 15 recreationally active females (mean age [±SD], 19.4 ± 2.1 years; mean height, 163.3 ± 5.9 cm; mean weight, 61.1 ± 7.1 kg) while performing SAGDL, SAGSL, FRONTDL, and FRONTSL jump landing tasks. Repeated-measures analyses of variance examined differences in lower extremity biomechanics between the 4 tasks, and linear regressions examined the extent to which an individual’s biomechanics during SAGDL were representative of their biomechanics during SAGSL, FRONTDL, and FRONTSL. Results: Lower extremity kinematics and kinetics differed by condition, with the SAGDL task generally eliciting greater hip and knee flexion angles and lower hip and knee forces than the other tasks (P < .05). Although biomechanics during the SAGDL task were strongly associated with those during the FRONTDL task (R 2, 0.41-0.82), weaker associations were observed between SAGDL and single-leg tasks for hip kinematics (R 2, 0.03-0.25) and kinetics (R 2, 0.05-0.20) and knee abduction moments (R 2, 0.06-0.18) (P < .05). Conclusion: Standard double-leg sagittal plane jump landing tasks used to screen for ACL injury risk and the effectiveness of ACL injury

  14. Modeling Localization of Amplitude-Panned Virtual Sources in Sagittal Planes

    PubMed Central

    BAUMGARTNER, ROBERT; MAJDAK, PIOTR

    2015-01-01

    Vector-base amplitude panning (VBAP) aims at creating virtual sound sources at arbitrary directions within multichannel sound reproduction systems. However, VBAP does not consistently produce listener-specific monaural spectral cues that are essential for localization of sound sources in sagittal planes, including the front-back and up-down dimensions. In order to better understand the limitations of VBAP, a functional model approximating human processing of spectro-spatial information was applied to assess accuracy in sagittal-plane localization of virtual sources created by means of VBAP. First, we evaluated VBAP applied on two loudspeakers in the median plane, and then we investigated the directional dependence of the localization accuracy in several three-dimensional loudspeaker arrangements designed in layers of constant elevation. The model predicted a strong dependence on listeners’ individual head-related transfer functions, on virtual source directions, and on loudspeaker arrangements. In general, the simulations showed a systematic degradation with increasing polar-angle span between neighboring loudspeakers. For the design of VBAP systems, predictions suggest that spans up to 40° polar angle yield a good trade-off between system complexity and localization accuracy. Special attention should be paid to the frontal region where listeners are most sensitive to deviating spectral cues. PMID:26441471

  15. Biomechanical Comparison of 3 Ankle Braces With and Without Free Rotation in the Sagittal Plane

    PubMed Central

    Alfuth, Martin; Klein, Dieter; Koch, Raphael; Rosenbaum, Dieter

    2014-01-01

    Context: Various designs of braces including hinged and nonhinged models are used to provide external support of the ankle. Hinged ankle braces supposedly allow almost free dorsiflexion and plantar flexion of the foot in the sagittal plane. It is unclear, however, whether this additional degree of freedom affects the stabilizing effect of the brace in the other planes of motion. Objective: To investigate the dynamic and passive stabilizing effects of 3 ankle braces, 2 hinged models that provide free plantar flexion–dorsiflexion in the sagittal plane and 1 ankle brace without a hinge. Design: Crossover study. Setting: University Movement Analysis Laboratory. Patients or Other Participants: Seventeen healthy volunteers (5 women, 12 men; age = 25.4 ± 4.8 years; height = 180.3 ± 6.5 cm; body mass = 75.5 ± 10.4 kg). Intervention(s): We dynamically induced foot inversion on a tilting platform and passively induced foot movements in 6 directions via a custom-built apparatus in 3 brace conditions and a control condition (no brace). Main Outcome Measure(s): Maximum inversion was determined dynamically using an in-shoe electrogoniometer. Passively induced maximal joint angles were measured using a torque and angle sensor. We analyzed differences among the 4 ankle-brace conditions (3 braces, 1 control) for each of the dependent variables with Friedman and post hoc tests (P < .05). Results: Each ankle brace restricted dynamic foot-inversion movements on the tilting platform as compared with the control condition, whereas only the 2 hinged ankle braces differed from each other, with greater movement restriction caused by the Ankle X model. Passive foot inversion was reduced with all ankle braces. Passive plantar flexion was greater in the hinged models as compared with the nonhinged brace. Conclusions: All ankle braces showed stabilizing effects against dynamic and passive foot inversion. Differences between the hinged braces and the nonhinged brace did not appear to be

  16. Influence of neck pain on cervical movement in the sagittal plane during smartphone use

    PubMed Central

    Kim, Man-Sig

    2015-01-01

    [Purpose] Smartphone use reportedly changes posture. However, how neck posture is altered in smartphone users with neck pain is unknown. This study examined changes in the posture of young adults with and without mild neck pain (MNP) when using a smartphone. [Subjects] Thirteen control subjects and 14 subjects with MNP who used smartphones were recruited. [Methods] The upper cervical (UC) and lower cervical (LC) angles in the sagittal plane were measured using an ultrasound-based motion analysis system while the seated subjects used a smartphone for 5 min. [Results] During smartphone use, the MNP group exhibited greater UC and LC flexion angles than the control group. [Conclusion] These findings suggest that young adults with MNP are more careful and more frequently utilize a neutral neck posture than young adults without MNP when using a smartphone while sitting. PMID:25642027

  17. A model of human knee ligaments in the sagittal plane. Part 2: Fibre recruitment under load.

    PubMed

    Zavatsky, A B; O'Connor, J J

    1992-01-01

    A mathematical model of the knee ligaments in the sagittal plane is used to study the forces in the cruciate and collateral ligaments produced by anterior/posterior tibial translation. The model is based on ligament fibre functional architecture. Geometric analysis of the deformed configurations of the model ligaments provides the additional compatibility conditions necessary for calculation of the statically indeterminate distributions of strain and stress within the ligaments and the sharing of load between ligaments. The investigation quantifies the process of ligament fibre recruitment, which occurs when fibres made slack by passive flexion/extension of the knee stretch and change their spatial positions in order to resist applied loads. The calculated ligament forces are in reasonable agreement with experimental results reported in the literature. The model explains some subtleties of ligament function not incorporated in models that represent the ligaments by a small number of lines. PMID:1482509

  18. Influence of neck pain on cervical movement in the sagittal plane during smartphone use.

    PubMed

    Kim, Man-Sig

    2015-01-01

    [Purpose] Smartphone use reportedly changes posture. However, how neck posture is altered in smartphone users with neck pain is unknown. This study examined changes in the posture of young adults with and without mild neck pain (MNP) when using a smartphone. [Subjects] Thirteen control subjects and 14 subjects with MNP who used smartphones were recruited. [Methods] The upper cervical (UC) and lower cervical (LC) angles in the sagittal plane were measured using an ultrasound-based motion analysis system while the seated subjects used a smartphone for 5 min. [Results] During smartphone use, the MNP group exhibited greater UC and LC flexion angles than the control group. [Conclusion] These findings suggest that young adults with MNP are more careful and more frequently utilize a neutral neck posture than young adults without MNP when using a smartphone while sitting. PMID:25642027

  19. A Dynamic Finite Element Analysis of Human Foot Complex in the Sagittal Plane during Level Walking

    PubMed Central

    Qian, Zhihui; Ren, Lei; Ding, Yun; Hutchinson, John R.; Ren, Luquan

    2013-01-01

    The objective of this study is to develop a computational framework for investigating the dynamic behavior and the internal loading conditions of the human foot complex during locomotion. A subject-specific dynamic finite element model in the sagittal plane was constructed based on anatomical structures segmented from medical CT scan images. Three-dimensional gait measurements were conducted to support and validate the model. Ankle joint forces and moment derived from gait measurements were used to drive the model. Explicit finite element simulations were conducted, covering the entire stance phase from heel-strike impact to toe-off. The predicted ground reaction forces, center of pressure, foot bone motions and plantar surface pressure showed reasonably good agreement with the gait measurement data over most of the stance phase. The prediction discrepancies can be explained by the assumptions and limitations of the model. Our analysis showed that a dynamic FE simulation can improve the prediction accuracy in the peak plantar pressures at some parts of the foot complex by 10%–33% compared to a quasi-static FE simulation. However, to simplify the costly explicit FE simulation, the proposed model is confined only to the sagittal plane and has a simplified representation of foot structure. The dynamic finite element foot model proposed in this study would provide a useful tool for future extension to a fully muscle-driven dynamic three-dimensional model with detailed representation of all major anatomical structures, in order to investigate the structural dynamics of the human foot musculoskeletal system during normal or even pathological functioning. PMID:24244500

  20. Comparison Between Interactive Closest Point and Procrustes Analysis for Determining the Median Sagittal Plane of Three-Dimensional Facial Data

    PubMed Central

    Xiong, Yuxue; Zhao, Yijiao; Yang, Huifang; Sun, Yucun; Wang, Yong

    2016-01-01

    Objective: To compare 2 digital methods to determine median sagittal plane of three-dimensional facial data—the interactive closest point algorithm and Procrustes analysis. Methods: The three-dimensional facial data of the 30 volunteers were got by the Face Scan 3D optical sensor (3D-Shape GmbH, Erlangen, Germany), and then were input to the reverse engineering software Imageware 13.0 (Siemens, Plano, TX) and Geomagic 2012 (Cary, NC). Their mirrored data were acquired and superimposed with the original data by the methods of interactive closest points and Procrustes analysis. The median sagittal planes of the 2 methods were extracted from the original and mirrored facial data respectively, 3 asymmetry indices were measured for comparison. Differences between the facial asymmetry indices of the 2 methods were evaluated using the paired sample t-test. Results: In terms of the 3 asymmetry indices, there were no significant differences between interactive closest points and Procrustes analysis for extracting median sagittal plane from three-dimensional facial data.(t = 0.0.060, P = 0.953 for asymmetry index (AI) 1, t = −0.926, P = 0.362 for AI 2, t = 1.1172, P = 0.0.251 for AI 3). Conclusions: In this evaluation of 30 subjects, the Procrustes analysis and the interactive closest point median-sagittal planes were similar in terms of the 3 asymmetry indices. Thus, Procrustes analysis and interactive closest point can both be used to abstract median sagittal plane from three-dimensional facial data. PMID:26825747

  1. Contributions of individual muscles to the sagittal- and frontal-plane angular accelerations of the trunk in walking.

    PubMed

    Klemetti, Rudolf; Steele, Katherine M; Moilanen, Petro; Avela, Janne; Timonen, Jussi

    2014-07-18

    This study was conducted to analyze the unimpaired control of the trunk during walking. Studying the unimpaired control of the trunk reveals characteristics of good control. These characteristics can be pursued in the rehabilitation of impaired control. Impaired control of the trunk during walking is associated with aging and many movement disorders. This is a concern as it is considered to increase fall risk. Muscles that contribute to the trunk control in normal walking may also contribute to it under perturbation circumstances, attempting to prevent an impending fall. Knowledge of such muscles can be used to rehabilitate impaired control of the trunk. Here, angular accelerations of the trunk induced by individual muscles, in the sagittal and frontal planes, were calculated using 3D muscle-driven simulations of seven young healthy subjects walking at free speed. Analysis of the simulations demonstrated that the abdominal and back muscles displayed large contributions throughout the gait cycle both in the sagittal and frontal planes. Proximal lower-limb muscles contributed more than distal muscles in the sagittal plane, while both proximal and distal muscles showed large contributions in the frontal plane. Along with the stance-limb muscles, the swing-limb muscles also exhibited considerable contribution. The gluteus medius was found to be an important individual frontal-plane control muscle; enhancing its function in pathologies could ameliorate gait by attenuating trunk sway. In addition, since gravity appreciably accelerated the trunk in the frontal plane, it may engender excessive trunk sway in pathologies. PMID:24873862

  2. Male and female runners demonstrate different sagittal plane mechanics as a function of static hamstring flexibility

    PubMed Central

    Williams III, D. S. Blaise; Welch, Lee M.

    2015-01-01

    ABSTRACT Background: Injuries to runners are common. However, there are many potential contributing factors to injury. While lack of flexibility alone is commonly related to injury, there are clear differences in hamstring flexibility between males and females. Objective: To compare the effect of static hamstring length on sagittal plane mechanics between male and female runners. Method: Forty subjects (30.0±6.4 years) participated and were placed in one of 4 groups: flexible males (n=10), inflexible males (n=10), flexible females (n=10), and inflexible females (n=10). All subjects were free of injury at the time of data collection. Three-dimensional kinematics and kinetics were collected while subjects ran over ground across 2 force platforms. Sagittal plane joint angles and moments were calculated at the knee and hip and compared with a 2-way (sex X flexibility) ANOVA (α=0.05). Results: Males exhibited greater peak knee extension moment than females (M=2.80±0.47, F=2.48±0.52 Nm/kg*m, p=0.05) and inflexible runners exhibited greater peak knee extension moment than flexible runners (In=2.83±0.56, Fl=2.44±0.51 Nm/kg*m, p=0.01). For hip flexion at initial contact, a significant interaction existed (p<0.05). Flexible females (36.7±7.4º) exhibited more hip flexion than inflexible females (27.9±4.6º, p<0.01) and flexible males (30.1±9.5º, p<0.05). No differences existed for knee angle at initial contact, peak knee angle, peak hip angle, or peak hip moment. Conclusion: Hamstring flexibility results in different mechanical profiles in males and females. Flexibility in the hamstrings may result in decreased moments via active or passive tension. These differences may have implications for performance and injury in flexible female runners. PMID:26537812

  3. Prediction of biomechanical parameters in the lumbar spine during static sagittal plane lifting.

    PubMed

    Kong, W Z; Goel, V K; Gilbertson, L G

    1998-04-01

    A combined approach involving optimization and the finite element technique was used to predict biomechanical parameters in the lumbar spine during static lifting in the sagittal plane. Forces in muscle fascicles of the lumbar region were first predicted using an optimization-based force model including the entire lumbar spine. These muscle forces as well as the distributed upper body weight and the lifted load were then applied to a three-dimensional finite element model of the thoracolumbar spine and rib cage to predict deformation, the intradiskal pressure, strains, stresses, and load transfer paths in the spine. The predicted intradiskal pressures in the L3-4 disk at the most deviated from the in vivo measurements by 8.2 percent for the four lifting cases analyzed. The lumbosacral joint flexed, while the other lumbar joints extended for all of the four lifting cases studied (rotation of a joint is the relative rotation between its two vertebral bodies). High stresses were predicted in the posterolateral regions of the endplates and at the junctions of the pedicles and vertebral bodies. High interlaminar shear stresses were found in the posterolateral regions of the lumbar disks. While the facet joints of the upper two lumbar segments did not transmit any load, the facet joints of the lower two lumbar segments experienced significant loads. The ligaments of all lumbar motion segments except the lumbosacral junction provided only marginal moments. The limitations of the current model and possible improvements are discussed. PMID:10412390

  4. A model of human knee ligaments in the sagittal plane. Part 1: Response to passive flexion.

    PubMed

    Zavatsky, A B; O'Connor, J J

    1992-01-01

    The development of a mathematical model of the knee ligaments in the sagittal plane is presented. Essential features of the model are (a) the representation of selected cruciate ligament fibres as isometric links in a kinematic mechanism that controls passive knee flexion and (b) the mapping of all other ligament fibres between attachments on the tibia and femur. Fibres slacken and tighten as the ligament attachment areas on the bones move relative to each other. The model is used to study the shape and fibre length changes of the cruciate and collateral ligaments in response to passive flexion/extension of the knee. The model ligament shape and fibre length changes compare well qualitatively with experimental results reported in the literature. The results suggest that when designing and implanting a ligament replacement with the aim of reproducing the natural fibre strain patterns, the surgeon must not only implant through the natural attachment areas but must also maintain the natural fibre mapping and render all fibres just tight at the appropriate flexion angle. PMID:1482508

  5. Deficits in Sagittal and Frontal Plane Mechanics during Drop Jump in Young Athletes with Recent Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Pace, James Lee; Brophy, Christopher; Mueske, Nicole; Katzel, Mia; Healy, Bitte S.; Wren, Tishya

    2016-01-01

    Objectives: While the vertical drop jump (VDJ) is an established predictor of ACL injury risk, most studies have focused on frontal and transverse plane assessment in young adult athletes. This study assessed sagittal as well as frontal plane biomechanics during VDJ in adolescent athletes following recent anterior cruciate ligament reconstruction (ACLR). Methods: 29 limbs with unilateral ACLR (69% female, mean age 15.8 ± 1.6 years, 5 to 12 months post-surgery), 29 contralateral non-operative limbs, and 19 control limbs (53% female, mean age of 15.5 ± 1.8 years) were evaluated during VDJ. Lower extremity three-dimensional kinematic and kinetic data from initial contact to peak knee flexion were compared among groups using analysis of variance with Bonferroni post-hoc tests. Results: The operative limbs had significantly lower peak ground reaction forces (GRF) than both control and contralateral limbs (ACLR: 1.7 body weights (BW), Contralateral: 2.1 BW, Control: 2.1 BW; p≤0.01) along with lower average external knee flexion moments (ACLR: 0.7Nm/kg, Contralateral: 0.9Nm/kg, Control: 1.1Nm/kg; p≤0.05) and reduced power absorption at the knee (ACLR: 0.9Nm/kg, Contralateral: 1.5Nm/kg, Control: 1.2Nm/kg; p≤0.01). Operative limbs had lower peak knee flexion (ACLR: 96.8°; Contralateral: 100.7°; p=0.001) and knee flexion excursion (ACLR: 75.0°, Contralateral: 82.5°; p=0.003) than contralateral limbs, but did not differ from controls in these measures. Both operative and non-operative limbs had greater peak hip flexion (ACLR: 98.9°, Contralateral: 99.8°, Control: 83.5°; p≤0.006), hip flexion excursion (ACLR: 60.8°, Contralateral: 65.6°, Control: 49.6°; p=), and power absorption at the hip (ACLR: 1.0Nm/kg, Contralateral: 1.2Nm/kg, Control: 0.7Nm/kg; p<0.03) compared with controls. In the coronal plane, both the operative and non-operative limbs demonstrated higher peak knee valgus moments compared to controls (ACLR: 0.5Nm/kg, Contralateral: 0.4Nm

  6. Sagittal plane rotation center of lower lumbar spine during a dynamic weight-lifting activity.

    PubMed

    Liu, Zhan; Tsai, Tsung-Yuan; Wang, Shaobai; Wu, Minfei; Zhong, Weiye; Li, Jing-Sheng; Cha, Thomas; Wood, Kirk; Li, Guoan

    2016-02-01

    This study investigated the center of rotation (COR) of the intervertebral segments of the lower lumbar spine (L4-L5 and L5-S1 segments) in sagittal plane during a weight-lifting (3.6 kg in each hand) extension activity performed with the pelvis constrained. Seven healthy subjects were studied using a dual fluoroscopic imaging technique. Using the non-weightbearing, supine position during MRI scan as a reference, the average intervertebral flexion angles of the L4-L5 and L5-S1 were 6.6° and 5.3° at flexion position of the body, respectively, and were -1.8° and -3.5° at extension position of the body, respectively. The CORs of the lower lumbar spine were found segment-dependent and changed with the body postures. The CORs of the L4-L5 segment were at the location about 75% posterior from the anterior edge of the disc at flexion positions of the body, and moved to about 92% of the posterior portion of the disc at extension positions of the body. The CORs of the L5-S1 segment were at 95% posterior portion of the disc at flexion positions of the body, and moved outside of the posterior edge of the disc by about 12% of the disc length at extension positions of the body. These results could help understand the physiological motion characters of the lower lumbar spine. The data could also provide important insights for future improvement of artificial disc designs and surgical implantation of the discs that are aimed to reproduce normal spinal functions. PMID:26805460

  7. A New Model to Produce Sagittal Plane Rotational Induced Diffuse Axonal Injuries

    PubMed Central

    Davidsson, Johan; Risling, Marten

    2011-01-01

    A new in vivo animal model that produces diffuse brain injuries in sagittal plane rearward rotational acceleration has been developed. In this model, the skull of an anesthetized adult rat is tightly secured to a rotating bar. During trauma, the bar is impacted by a striker that causes the bar and the animal head to rotate rearward; the acceleration phase last 0.4 ms and is followed by a rotation at constant speed and a gentle deceleration when the bar makes contact with a padded stop. The total head angle change is less than 30°. By adjusting the air pressure in the rifle used to accelerate the striker, resulting rotational acceleration between 0.3 and 2.1 Mrad/s2 can be produced. Numerous combinations of trauma levels, post-trauma survival times, brain and serum retrieval, and tissue preparation techniques were adopted to characterize this new model. The trauma caused subdural bleedings in animals exposed to severe trauma. Staining brain tissue with β-Amyloid Precursor Protein antibodies and FD Neurosilver that detect degenerating axons revealed wide spread axonal injuries (AI) in the corpus callosum, the border between the corpus callosum and cortex and in tracts in the brain stem. The observed AIs were apparent only when the rotational acceleration level was moderate and above. On the contrary, only limited signs of contusion injuries were observed following trauma. Macrophage invasions, glial fibrillary acidic protein redistribution or hypertrophy, and blood brain barrier (BBB) changes were unusual. S100 serum analyses indicate that blood vessel and glia cell injuries occur following moderate levels of trauma despite the absence of obvious BBB injuries. We conclude that this rotational trauma model is capable of producing graded axonal injury, is repeatable and produces limited other types of traumatic brain injuries and as such is useful in the study of injury biomechanics, diagnostics, and treatment strategies following diffuse axonal injury. PMID

  8. Exploration of the validity of the two-dimensional sagittal plane assumption in modeling the standing long jump.

    PubMed

    Hickox, Lauren J; Ashby, Blake M; Alderink, Gordon J

    2016-05-01

    Most previous standing long jump studies have been based on the assumption of two-dimensional sagittal plane motion with bilateral symmetry. The purpose of this study was to investigate the validity of this assumption. Standing long jump trials were collected using six adult male participants. Each participant stood with a foot on each of two force plates and performed eight standing long jumps for maximal distance. Inverse dynamics analyses were performed for two-dimensional (2D) and three-dimensional (3D) models, and joint moments, powers, and work values were compared. The differences between these models with respect to the validity of the common planar jumping assumption were analyzed. Good agreement was observed between 2D and 3D methods for the lower body, with minimal differences in sagittal plane moments, power, and work for the ankle, knee, and lower back. There were significant, but relatively small differences in the sagittal plane kinematics and kinetics at the hip. For the upper body, the results contradicted the sagittal plane assumption in that significant moments and power were generated about the abduction/adduction axis of the shoulder and a similar amount of work was performed about both abduction/adduction and flexion/extension axes of the shoulder. The elbow also showed significant differences in power and work. These results indicate that an assumption of planar motion should be sufficient for many studies of the standing long jump that only examine lower body movement. However, for studies that include upper body motion, diagnosing injury risk, or investigating gender differences, a 3D model may be more appropriate. PMID:26949101

  9. Reliability of a simple fluoroscopic method to study sagittal plane femorotibial contact changes in total knee arthroplasties during flexion.

    PubMed

    Lacoste, C; Granizo, J J; Gómez-Barrena, E

    2007-08-01

    Clinical interest in sagittal plane kinematic analysis of the knee undergoing total knee replacement fosters the development of simple, reliable methods to estimate femorotibial contact in a regular clinical setting. In this study, the sagittal femorotibial contact was analysed in lateral X-rays and lateral fluoroscopic views, from extension to knee flexion. Quantitative and categorical data were obtained from these views by two different observers, and compared with data from direct views of the components. Interobserver and intermethod errors for quantitative and categorical data were evaluated based on correlation, kappa coefficient, and Bland-Altman graphs. Interobserver reproducibility of quantitative measurement from fluoroscopic views was r=0.96 while categorical assignment exhibited a kappa coefficient of 0.95. Reproducibility from plain radiographs was not so high, with a kappa coefficient of 0.64. High concordance was also obtained when the method was compared with the direct view of the implant, supporting these measurement techniques. Bland-Altman graphs confirmed the absence of bias in the intermethod comparison. Therefore, with the obvious limitation of rotational assessment, lateral fluoroscopic evaluation enhanced by a simple fitting technique can be used as a valuable tool for clinical evaluation of knee kinematics in the sagittal plane. PMID:17553683

  10. Radiographic measurement of the sagittal plane deformity in patients with osteoporotic spinal fractures evaluation of intrinsic error

    PubMed Central

    Pekmezci, Murat; Karaeminogulları, Oguz; Acaroglu, Emre; Yazıcı, Muharrem; Cil, Akın; Pijnenburg, Bas; Genç, Yasemin; Oner, Fethullah C.

    2007-01-01

    Cobb method has been shown to be the most reliable technique with a reasonable measurement error to determine the kyphosis in fresh fractures of young patients. However, measurement errors may be higher for elderly patients as it may be difficult to determine the landmarks due to osteopenia and the degenerative changes. The aim of this study is to investigate the intrinsic error for different techniques used in evaluation of local sagittal plane deformity caused by OVCF. Lateral X-rays of OVCF patients were randomly selected. Patient group was composed of 28 females and 7 males and the mean age was 62.7 (55–75) years. The kyphosis angle and the vertebral body height were analyzed to reveal the severity of sagittal plane deformity. Kyphotic deformity was measured by using four different techniques; and the vertebral body heights (VBH) were measured at three different points. The mean intra-observer agreement interval for kyphosis angle measurement techniques ranged from ±7.1 to ±9.3° while it ranged from ±4.5 to ±6.5 mm for VBH measurement techniques. The mean interobserver agreement interval for kyphosis angle ranged from ±8.2 to ±11.1°, while it was between ±4.5 to ±6.5 mm for vertebral body height measurement techniques. This study revealed that although the intra and interobserver agreement were similar for all techniques, they are still higher than expected. These high intervals for measurement errors should be taken into account when interpreting the results of correction in local sagittal plane deformities of OVCF patients after surgical procedures such as vertebral augmentation techniques. PMID:17912558

  11. Effect of the hip motion on the body kinematics in the sagittal plane during human quiet standing.

    PubMed

    Sasagawa, Shun; Ushiyama, Junichi; Kouzaki, Motoki; Kanehisa, Hiroaki

    2009-01-23

    Human quiet stance is often modeled as a single-link inverted pendulum pivoting only around the ankle joints in the sagittal plane. However, several recent studies have shown that movement around the hip joint cannot be negligible, and the body behaves like a double-link inverted pendulum. The purpose of this study was to examine how the hip motion affects the body kinematics in the sagittal plane during quiet standing. Ten healthy subjects were requested to keep a quiet stance for 30s on a force platform. The angular displacements of the ankle and hip joints were measured using two highly sensitive CCD laser sensors. By taking the second derivative of the angular displacements, the angular accelerations of both joints were obtained. As for the angular displacements, there was no clear correlation between the ankle and hip joints. On the other hand, the angular accelerations of both joints were found to be modulated in a consistent anti-phase pattern. Then we estimated the anterior-posterior (A-P) acceleration of the center of mass (CoM) as a linear summation of the angular acceleration data. Simultaneously, we derived the actual CoM acceleration by dividing A-P share force by body mass. When we estimated CoM acceleration using only the angular acceleration of the ankle joint under the assumption that movement of the CoM is merely a scaled reflection of the motion of the ankle, it was largely overestimated as compared to the actual CoM acceleration. Whereas, when we take the angular acceleration of the hip joint into the calculation, it showed good coincidence with the actual CoM acceleration. These results indicate that the movement around the hip joint has a substantial effect on the body kinematics in the sagittal plane even during quiet standing. PMID:19027828

  12. THE INFLUENCE OF HEEL HEIGHT ON SAGITTAL PLANE KNEE KINEMATICS DURING LANDING TASKS IN RECREATIONALLY ACTIVE AND ATHLETIC COLLEGIATE FEMALES

    PubMed Central

    Carcia, Christopher R.; Phelps, Amy L.; Martin, RobRoy L.; Burrows, Anne M.

    2011-01-01

    Purpose: To determine if heel height alters sagittal plane knee kinematics when landing from a forward hop or drop landing. Background: Knee angles close to extension during landing are theorized to increase ACL injury risk in female athletes. Methods: Fifty collegiate females performed two single-limb landing tasks while wearing heel lifts of three different sizes (0, 12 & 24 mm) attached to the bottom of a sneaker. Using an electrogoniometer, sagittal plane kinematics (initial contact [KAIC], peak flexion [KAPeak], and rate of excursion [RE]) were examined. Repeated measures ANOVAs were used to determine the influence of heel height on the dependent measures. Results: Forward hop task- KAIC with 0 mm, 12 mm, and 24 mm lifts were 8.88±6.5, 9.38±5.8 and 11.28±7.0, respectively. Significant differences were noted between 0 and 24 mm lift (p<.001) and 12 and 24 mm lifts (p=.003), but not between the 0 and 12 mm conditions (p=.423). KAPeak with 0 mm, 12 mm, and 24 mm lifts were 47.08±10.9, 48.18±10.3 and 48.88±9.7, respectively. A significant difference was noted between 0 and 24 mm lift (p=.004), but not between the 0 and 12 mm or 12 and 24 mm conditions (p=.071 and p=.282, respectively). The RE decreased significantly from 2128/sec±52 with the 12 mm lift to 1958/sec±55 with the 24 mm lift (p=.004). RE did not differ from 0 to 12 or 0 to 24 mm lift conditions (p=.351 and p=.086, respectively). Jump-landing task- No significant differences were found in KAIC (p=.531), KAPeak (p=.741), or the RE (p=.190) between any of the heel lift conditions. Conclusions: The addition of a 24 mm heel lift to the bottom of a sneaker significantly alters sagittal plane knee kinematics upon landing from a unilateral forward hop but not from a drop jump. PMID:21904697

  13. [Study of the inclination angle between the edentulous upper and lower alveolar ridge in the sagittal plane].

    PubMed

    Esztári, I; Fejérdy, L; Kaán, M; Fejérdy, P

    2000-05-01

    Angle of inclination between the upper and lower edentulous alveolar ridge in the sagittal plane was examined on 72 patients (55 woman and 17 men) in centric occlusion. Photos were taken by a special camera (Polaroid MACRO 5 SLR) of the functional casts mounted in average value articulators, on a special squared-film, from the left and right side. The angle between the lines connecting mesially the midline of the alveolar ridge, distally the highest point of the tuber alveolar maxillae and the line drown through the stop-lines, respectively was measured on both sides with 1 degree precision. Distally open angle (max. 7 degrees) was found in 11% of the examine group. The alveolar ridge lines were parallel in only 3% of the cases. Mesially open angle (max. 20 degrees) was found at 86%. Statistical analysis has shown, that there is a significant difference between men and women as well as the left and right side. PMID:10846819

  14. Fast, Accurate and Precise Mid-Sagittal Plane Location in 3D MR Images of the Brain

    NASA Astrophysics Data System (ADS)

    Bergo, Felipe P. G.; Falcão, Alexandre X.; Yasuda, Clarissa L.; Ruppert, Guilherme C. S.

    Extraction of the mid-sagittal plane (MSP) is a key step for brain image registration and asymmetry analysis. We present a fast MSP extraction method for 3D MR images, based on automatic segmentation of the brain and on heuristic maximization of the cerebro-spinal fluid within the MSP. The method is robust to severe anatomical asymmetries between the hemispheres, caused by surgical procedures and lesions. The method is also accurate with respect to MSP delineations done by a specialist. The method was evaluated on 64 MR images (36 pathological, 20 healthy, 8 synthetic), and it found a precise and accurate approximation of the MSP in all of them with a mean time of 60.0 seconds per image, mean angular variation within a same image (precision) of 1.26o and mean angular difference from specialist delineations (accuracy) of 1.64o.

  15. Flexion test in the coronal plane deformities of knee

    PubMed Central

    Gautam, V.K.; Maini, Lalit; Gupta, Rajat; Sabharwal, Akash; Arora, Sumit

    2013-01-01

    Background/aims A little information is available in the orthopaedic literature on the clinical bedside assessment of the coronal plane deformities of the knee. We aim to explain the ‘knee flexion test’ to make it useful for the clinicians and the students learning the art of orthopaedics. Methods and results We describe the principle, pre-requisites, fallacy, and modification of the ‘knee flexion test’ along with the illustrative case description that had genu valgum deformity of the left knee of tibial origin. Conclusion The ‘knee flexion test’ should be a part of clinical bedside assessment of the coronal plane deformities of the knee. PMID:26403549

  16. Effect of Acute Alterations in Foot Strike Patterns during Running on Sagittal Plane Lower Limb Kinematics and Kinetics.

    PubMed

    Valenzuela, Kevin A; Lynn, Scott K; Mikelson, Lisa R; Noffal, Guillermo J; Judelson, Daniel A

    2015-03-01

    The purpose of this study was to determine the effect of foot strike patterns and converted foot strike patterns on lower limb kinematics and kinetics at the hip, knee, and ankle during a shod condition. Subjects were videotaped with a high speed camera while running a 5km at self-selected pace on a treadmill to determine natural foot strike pattern on day one. Preferred forefoot group (PFFG, n = 10) and preferred rear foot group (PRFG, n = 11) subjects were identified through slow motion video playback (n = 21, age = 22.8±2.2 years, mass = 73.1±14.5 kg, height 1.75 ± 0.10 m). On day two, subjects performed five overground run trials in both their natural and unnatural strike patterns while motion and force data were collected. Data were collected over two days so that foot strike videos could be analyzed for group placement purposes. Several 2 (Foot Strike Pattern -forefoot strike [FFS], rearfoot strike [RFS]) x 2 (Group - PFFG, PRFG) mixed model ANOVAs (p < 0.05) were run on speed, active peak vertical ground reaction force (VGRF), peak early stance and mid stance sagittal ankle moments, sagittal plane hip and knee moments, ankle dorsiflexion ROM, and sagittal plane hip and knee ROM. There were no significant interactions or between group differences for any of the measured variables. Within subject effects demonstrated that the RFS condition had significantly lower (VGRF) (RFS = 2.58 ± .21 BW, FFS = 2.71 ± 0.23 BW), dorsiflexion moment (RFS = -2.6 1± 0.61 Nm·kg(-1), FFS = -3.09 ± 0.32 Nm·kg(-1)), and dorsiflexion range of motion (RFS = 17.63 ± 3.76°, FFS = 22.10 ± 5.08°). There was also a significantly higher peak plantarflexion moment (RFS = 0.23 ± 0.11 Nm·kg(-1), FFS = 0.01 ± 0.01 Nm·kg(-1)), peak knee moment (RFS = 2.61 ± 0.54 Nm·kg(-1), FFS = 2.39 ± 0.61 Nm·kg(-1)), knee ROM (RFS = 31.72 ± 2.79°, FFS = 29.58 ± 2.97°), and hip ROM (RFS = 42.72 ± 4.03°, FFS = 41.38 ± 3.32°) as compared with the FFS condition. This research suggests

  17. Effect of Acute Alterations in Foot Strike Patterns during Running on Sagittal Plane Lower Limb Kinematics and Kinetics

    PubMed Central

    Valenzuela, Kevin A.; Lynn, Scott K.; Mikelson, Lisa R.; Noffal, Guillermo J.; Judelson, Daniel A.

    2015-01-01

    The purpose of this study was to determine the effect of foot strike patterns and converted foot strike patterns on lower limb kinematics and kinetics at the hip, knee, and ankle during a shod condition. Subjects were videotaped with a high speed camera while running a 5km at self-selected pace on a treadmill to determine natural foot strike pattern on day one. Preferred forefoot group (PFFG, n = 10) and preferred rear foot group (PRFG, n = 11) subjects were identified through slow motion video playback (n = 21, age = 22.8±2.2 years, mass = 73.1±14.5 kg, height 1.75 ± 0.10 m). On day two, subjects performed five overground run trials in both their natural and unnatural strike patterns while motion and force data were collected. Data were collected over two days so that foot strike videos could be analyzed for group placement purposes. Several 2 (Foot Strike Pattern –forefoot strike [FFS], rearfoot strike [RFS]) x 2 (Group – PFFG, PRFG) mixed model ANOVAs (p < 0.05) were run on speed, active peak vertical ground reaction force (VGRF), peak early stance and mid stance sagittal ankle moments, sagittal plane hip and knee moments, ankle dorsiflexion ROM, and sagittal plane hip and knee ROM. There were no significant interactions or between group differences for any of the measured variables. Within subject effects demonstrated that the RFS condition had significantly lower (VGRF) (RFS = 2.58 ± .21 BW, FFS = 2.71 ± 0.23 BW), dorsiflexion moment (RFS = -2.6 1± 0.61 Nm·kg-1, FFS = -3.09 ± 0.32 Nm·kg-1), and dorsiflexion range of motion (RFS = 17.63 ± 3.76°, FFS = 22.10 ± 5.08°). There was also a significantly higher peak plantarflexion moment (RFS = 0.23 ± 0.11 Nm·kg-1, FFS = 0.01 ± 0.01 Nm·kg-1), peak knee moment (RFS = 2.61 ± 0.54 Nm·kg-1, FFS = 2.39 ± 0.61 Nm·kg-1), knee ROM (RFS = 31.72 ± 2.79°, FFS = 29.58 ± 2.97°), and hip ROM (RFS = 42.72 ± 4.03°, FFS = 41.38 ± 3.32°) as compared with the FFS condition. This research suggests that

  18. Design of an automated device to measure sagittal plane stiffness of an articulated ankle-foot orthosis.

    PubMed

    Kobayashi, Toshiki; Leung, Aaron K L; Akazawa, Yasushi; Naito, Hisashi; Tanaka, Masao; Hutchins, Stephen W

    2010-12-01

    The purpose of this study was to design a new automated stiffness measurement device which could perform a simultaneous measurement of both dorsi- and plantarflexion angles and the corresponding resistive torque around the rotational centre of an articulated ankle-foot orthosis (AAFO). This was achieved by controlling angular velocities and range of motion in the sagittal plane. The device consisted of a hydraulic servo fatigue testing machine, a torque meter, a potentiometer, a rotary plate and an upright supporter to enable an AAFO to be attached to the device via a surrogate shank. The accuracy of the device in reproducing the range of motion and angular velocity was within 4% and 1% respectively in the range of motion of 30° (15° plantarflexion to 15° dorsiflexion) at the angular velocity of 10°/s, while that in the measurement of AAFO torque was within 8% at the 0° position. The device should prove useful to assist an orthotist or a manufacturer to quantify the stiffness of an AAFO and inform its clinical use. PMID:20681928

  19. Task-Level Strategies for Human Sagittal-Plane Running Maneuvers Are Consistent with Robotic Control Policies

    PubMed Central

    Qiao, Mu; Jindrich, Devin L.

    2012-01-01

    The strategies that humans use to control unsteady locomotion are not well understood. A “spring-mass” template comprised of a point mass bouncing on a sprung leg can approximate both center of mass movements and ground reaction forces during running in humans and other animals. Legged robots that operate as bouncing, “spring-mass” systems can maintain stable motion using relatively simple, distributed feedback rules. We tested whether the changes to sagittal-plane movements during five running tasks involving active changes to running height, speed, and orientation were consistent with the rules used by bouncing robots to maintain stability. Changes to running height were associated with changes to leg force but not stance duration. To change speed, humans primarily used a “pogo stick” strategy, where speed changes were associated with adjustments to fore-aft foot placement, and not a “unicycle” strategy involving systematic changes to stance leg hip moment. However, hip moments were related to changes to body orientation and angular speed. Hip moments could be described with first order proportional-derivative relationship to trunk pitch. Overall, the task-level strategies used for body control in humans were consistent with the strategies employed by bouncing robots. Identification of these behavioral strategies could lead to a better understanding of the sensorimotor mechanisms that allow for effective unsteady locomotion. PMID:23284804

  20. NOTE: Determination of isocentric machine parameters for inclined treatment volumes: a single solution for angled transverse or coronal treatment planes

    NASA Astrophysics Data System (ADS)

    Bradley, F. L.

    2001-01-01

    The derivation of the trigonometric equations necessary to calculate gantry, floor and collimator settings for a treatment plane at an angle φ to the transverse plane of the patient has been described previously. The derivation of a second set of equations to facilitate treatment in a plane at an angle φ to the coronal plane has also been described previously. This work reinterprets the geometry of inclined volumes and shows that essentially only one set of equations is required to determine the settings for treatment planes at an angle φ to either the transverse or coronal planes of the patient.

  1. The effect of centre of mass location on sagittal plane moments around the centre of mass in trotting horses.

    PubMed

    Hobbs, Sarah Jane; Richards, Jim; Clayton, Hilary M

    2014-04-11

    The diagonal limb support pattern at trot provides pitch and roll stability, but little is known about the control of moments about the centre of mass (COM) in horses. Correct COM location is critical in the calculation of pitching moments. The objectives were to determine the effect of COM location on pitching moments in trotting horses and explore how COM location could influence balance. Kinematic (120 Hz) and GRF (4 force plates, 960 Hz) data were collected at trot from three trials of eight horses. The position of the COM was determined from the weighted summation of the segmental COMs and this was then manipulated cranially and caudally to test the model. Sagittal-plane moments around the COM were calculated for each manipulation of the model and their relationship determined using reduced major axis regression. Over the stride, the moments must sum to zero to prevent accumulation of rotational motion. This was found when the weight on the forelimbs in standing was 58.7% ± 3% (mean ± 95% C.I.), which corresponded closely to the COP ratio in standing. Moments were typically nose-up at foot strike changing to nose-down prior to midstance, and then reversing to nose-up in late stance. Mean moments were larger in the hindlimbs and more sensitive to COM location changes. Divergence of the COM from the COP creating a vertical force moment arm prior to midstance may assist the hindlimb in relation to propulsive effort. A similar effect is seen in the forelimb during single limb support. PMID:24636530

  2. Effects of a functional foot orthosis on the knee angle in the sagittal plane of college students in their 20s with flatfoot

    PubMed Central

    Park, KwangYong; Seo, KyoChul

    2015-01-01

    [Purpose] The purpose of this study was to examine the effects of a functional foot orthosis on the knee angle in the sagittal plane of college students in their 20s who had flatfoot. [Subjects and Methods] The subjects of this study were 20 college students diagnosed as having flatfoot. The variations of their knee angle (Q-angle) in the sagittal plane during the stance phase were measured using the VICON Motion System (Vicon, Hansung, Korea) before and while wearing a foot orthosis. The experimental data were analyzed using SPSS 12.0 for Windows. [Results] The Q-angle in the test group during the stance phase showed statistically significant declines on the right and left sides while wearing the foot orthosis during the gait-phases of loading response and midstance. During initial contact, terminal stance, and preswing, the Q-angle also decreased on the right and left sides after wearing the foot orthosis, but the changes were not statistically significant. [Conclusion] The college students with flatfoot exhibited declines in the Q-angle in the sagittal plane while wearing a foot orthosis. In this regard, the application of active gait training using orthotic shoes for long hours is likely to help individuals with flatfoot to achieve normal gait. PMID:25995591

  3. The plane of polarization of the solar coronal emission on August 11, 1999

    NASA Astrophysics Data System (ADS)

    Park, Y.-D.; Kim, I. S.; Bugaenko, O. I.; Divlekeev, M. I.; Popov, V. V.; Dermenjiev, V. N.

    2001-09-01

    A two-dimensional polarization image of the inner regions of the solar corona (R≤1.5R ȩ) during the total solar eclipse of August 11, 1999 is presented. This image clearly exhibits both small-and large-scale structure in the distribution of deviations of the plane of polarization from its theoretical direction for coronal emission in the near infrared (570 800 nm). An accuracy for the deviation angles of ≤1° was achieved by reducing the instrumental scattered light in the telescope, installing a continuously rotating polaroid near the image plane of the entrance pupil (i.e., the Lyot stop plane), and developing a special algorithm for constructing the polarization images based on the IDL software, in which the properties of the light are described in terms of the Stokes parameters. This algorithm was used to process 24 digitized polarization images of the corona, corresponding to one complete rotation of the polaroid. Analysis of the polarization image for angles of 0° 5° indicates the existence of significant deviations in the inner corona. The polar and equatorial coronal regions are characterized by diffuse and almost uniform structure of the deviation angles, 0.5° ± 0.5°, corresponding to Thomson scattering of the photospheric radiation by free electrons. Four large-scale structures over the NE, SE, NW, and SW limbs covering about 60° in position angle have deviations of 1° 3°. Numerous small-scale structures with dimensions up to 30″ and deviation angles of 3° 5° tracing strongly curved coronal streamers were detected in active coronal regions, especially over the NE limb. Interpretation of these deviations in terms of flows of moving electrons implies tangential velocities of up to 2.5×104 km/s, i.e., electron energies of up to 2×103 eV.

  4. Shoulder motor performance assessment in the sagittal plane in children with hemiplegia during single joint pointing tasks

    PubMed Central

    2014-01-01

    Background Pointing is a motor task extensively used during daily life activities and it requires complex visuo-motor transformation to select the appropriate movement strategy. The study of invariant characteristics of human movements has led to several theories on how the brain solves the redundancy problem, but the application of these theories on children affected by hemiplegia is limited. This study aims at giving a quantitative assessment of the shoulder motor behaviour in children with hemiplegia during pointing tasks. Methods Eight children with hemiplegia were involved in the study and were asked to perform movements on the sagittal plane with both arms, at low and high speed. Subject movements were recorded using an optoelectronic system; a 4-DOF model of children arm has been developed to calculate kinematic and dynamic variables. A set of evaluation indexes has been extracted in order to quantitatively assess whether and how children modify their motor control strategies when perform movements with the more affected or less affected arm. Results In low speed movements, no differences can be seen in terms of movement duration and peak velocity between the More Affected arm (MA) and the Less Affected arm (LA), as well as in the main characteristics of movement kinematics and dynamics. As regards fast movements, remarkable differences in terms of strategies of motor control can be observed: while movements with LA did not show any significant difference in Dimensionless Jerk Index (JI) and Dimensionless Torque-change Cost index (TC) between the elevation and lowering phases, suggesting that motor control optimization is similar for movements performed with or against gravity, movements with MA showed a statistically significant increase of both JI and TC during lowering phase. Conclusions Results suggest the presence of a different control strategy for fast movements in particular during lowering phase. Results suggest that motor control is not able to

  5. Correlations between sagittal plane kinematics and landing impact force during single-leg lateral jump-landings

    PubMed Central

    Aizawa, Junya; Ohji, Shunsuke; Koga, Hideyuki; Masuda, Tadashi; Yagishita, Kazuyoshi

    2016-01-01

    [Purpose] The correlations of peak vertical ground reaction force and sagittal angles during single-leg lateral jump-landing with noncontact anterior cruciate ligament injury remain unknown. This study aimed to clarify the correlations between kinematics and impact force during lateral jump-landing. [Subjects and Methods] Twenty active males were included in the analysis. A sagittal-view movie camera and force plate were time synchronized. Trunk and lower extremity sagittal angles were measured 100 ms before initial contact and at peak vertical ground reaction force. Peak vertical ground reaction force, time between initial contact and peak vertical ground reaction force, and loading rate were calculated. [Results] The mean sagittal angle was 40.7° ± 7.7° for knee flexion during the flight phase and 16.4° ± 6.3° for pelvic anterior inclination during the landing phase. The mean peak vertical ground reaction force was four times the body weight. The median time to peak vertical ground reaction force was 63.8 ms. The knee flexion during the flight phase and pelvic anterior inclination angles during the landing phase were related to the peak vertical ground reaction force. [Conclusion] Increasing knee flexion and decreasing pelvic anterior inclination might reduce the impact during single-leg lateral jump-landing.

  6. Three-dimensional imaging of the uterus: The value of the coronal plane

    PubMed Central

    Wong, Lufee; White, Nikki; Ramkrishna, Jayshree; Júnior, Edward Araujo; Meagher, Simon; Costa, Fabricio Da Silva

    2015-01-01

    Advent in three-dimensional (3D) imaging technology has seen 3D ultrasound establish itself as a useful adjunct complementary to traditional two-dimensional imaging of the female pelvis. This advantage largely arises from its ability to reconstruct the coronal plane of the uterus, which allows further delineation of many gynecological disorders. 3D imaging of the uterus is now the preferred imaging modality for assessing congenital uterine anomalies and intrauterine device localization. Newer indications include the diagnosis of adenomyosis. It can also add invaluable information to delineate other endometrial and myometrial pathology such as fibroids and endometrial polyps. PMID:26753063

  7. Three-dimensional imaging of the uterus: The value of the coronal plane.

    PubMed

    Wong, Lufee; White, Nikki; Ramkrishna, Jayshree; Araujo Júnior, E; Meagher, Simon; Costa, Fabricio Da Silva

    2015-12-28

    Advent in three-dimensional (3D) imaging technology has seen 3D ultrasound establish itself as a useful adjunct complementary to traditional two-dimensional imaging of the female pelvis. This advantage largely arises from its ability to reconstruct the coronal plane of the uterus, which allows further delineation of many gynecological disorders. 3D imaging of the uterus is now the preferred imaging modality for assessing congenital uterine anomalies and intrauterine device localization. Newer indications include the diagnosis of adenomyosis. It can also add invaluable information to delineate other endometrial and myometrial pathology such as fibroids and endometrial polyps. PMID:26753063

  8. The Coronal Plane High Tibial Osteotomy. Part 1: A Clinical and Radiographic Analysis of Intermediate Term Outcomes

    PubMed Central

    Fealy, Stephen; Lyman, Stephen; Wickiewicz, Thomas L.

    2007-01-01

    The coronal plane high tibial osteotomy is a novel technique that is used to treat tibiofemoral malalignment. The authors hypothesize that the coronal plane high tibial osteotomy is (1) efficacious in treating both varus and valgus tibiofemoral malalignment; (2) does not alter the slope of the proximal tibia; and (3) does not alter the relationship between the patella and tibial tubercle. A retrospective review of 25 patients with tibiofemoral malalignment (19 varus/6 valgus) treated with a coronal plane osteotomy with a minimum of 2-year follow-up was performed. A Kaplan–Meyer survival curve was performed using knee arthroplasty and a Hospital for Special Surgery (HSS) knee score <70 as failure criteria. The Insall–Salvati ratio and the proximal tibial slope were measured. A p value of 0.05 was considered significant. At 60-month follow-up, knees with initial varus malalignment had an 84% survival rate using both knee arthroplasty and the HSS score as endpoints. Knees with initial valgus malalignment had an 84 and 60% survival rate using knee arthroplasty and the HSS score as endpoints, respectively. There was no statistically significant change in the Insall–Salvati ratio and proximal tibial slope after coronal plane osteotomy. The coronal plane osteotomy is efficacious in treating varus and valgus tibiofemoral malalignment and does not alter the patellar–tibial tubercle relationship or the posterior tibial slope [case series (level of evidence: IV)]. PMID:18751785

  9. Effects of follower load and rib cage on intervertebral disc pressure and sagittal plane curvature in static tests of cadaveric thoracic spines.

    PubMed

    Anderson, Dennis E; Mannen, Erin M; Sis, Hadley L; Wong, Benjamin M; Cadel, Eileen S; Friis, Elizabeth A; Bouxsein, Mary L

    2016-05-01

    The clinical relevance of mechanical testing studies of cadaveric human thoracic spines could be enhanced by using follower preload techniques, by including the intact rib cage, and by measuring thoracic intervertebral disc pressures, but studies to date have not incorporated all of these components simultaneously. Thus, this study aimed to implement a follower preload in the thoracic spine with intact rib cage, and examine the effects of follower load, rib cage stiffening and rib cage removal on intervertebral disc pressures and sagittal plane curvatures in unconstrained static conditions. Intervertebral disc pressures increased linearly with follower load magnitude. The effect of the rib cage on disc pressures in static conditions remains unclear because testing order likely confounded the results. Disc pressures compared well with previous reports in vitro, and comparison with in vivo values suggests the use of a follower load of about 400N to approximate loading in upright standing. Follower load had no effect on sagittal plane spine curvature overall, suggesting successful application of the technique, although increased flexion in the upper spine and reduced flexion in the lower spine suggest that the follower load path was not optimized. Rib cage stiffening and removal both increased overall spine flexion slightly, although with differing effects at specific spinal locations. Overall, the approaches demonstrated here will support the use of follower preloads, intact rib cage, and disc pressure measurements to enhance the clinical relevance of future studies of the thoracic spine. PMID:26944690

  10. A rare case of steering wheel injury causing coronal-plane pancreatic lacerations.

    PubMed

    Sato, Takako; Kashiwai, Aya; Ota, Chisato; Nomura, Masakatsu; Tsuboi, Kento; Kitagawa, Misa; Abe, Shuntaro; Tsuchihashi, Hitoshi; Suzuki, Koichi

    2016-07-01

    The incidence of pancreatic injury after blunt abdominal trauma is extremely low. A timely and accurate diagnosis is important, as a delay could be life-threatening. In this case, a 70-year-old driver crashed a car into a concrete wall at low speed. He was transported to the emergency hospital but died about 9.5h later with the cause of death unknown. An autopsy revealed that his pancreas was lacerated in the coronal plane and there was mesenteric contusion. Cause of death was determined to be blood loss resulting from pancreatic and mesenteric contusion. The mechanism of the injury was considered to be a very rare "degloving," caused by the impact from the steering wheel. It is therefore important to keep in mind possible pancreatic damage when examining blunt trauma to the abdomen, especially in traffic accident cases. PMID:27497337

  11. Age-related differences in sagittal-plane knee function at heel-strike of walking are increased in osteoarthritic patients

    PubMed Central

    Favre, Julien; Erhart-Hledik, Jennifer C.; Andriacchi, Thomas P.

    2014-01-01

    Objective. To compare age-related patterns of gait with patterns associated with knee osteoarthritis (OA), the following hypotheses were tested: H1) The sagittal-plane knee function during walking is different between younger and older asymptomatic subjects; H2) The age-related differences in H1 are increased in patients with knee OA. Design. Walking trials were collected for 110 participants (1.70 ± 0.09 m, 80 ± 14 kg). There were 29 younger asymptomatic subjects (29 ± 4 years) and 81 older participants (59 ± 9 years), that included 27 asymptomatic subjects and 28 and 26 patients with moderate and severe medial knee OA. Discrete variables characterizing sagittal-plane knee function were compared among the four groups using ANOVAs. Results. During the heel-strike portion of the gait the cycle at preferred walking speed, the knee was less extended and the shank less inclined in the three older groups compared to the younger asymptomatic group. There were similar differences between the severe OA group and the older asymptomatic and moderate OA groups. Both OA groups also had the femur less posterior relative to the tibia and smaller extension moment than the younger group. During terminal stance, the severe OA group had the knee less extended and smaller knee extension moment than the younger asymptomatic and older moderate OA groups. Conclusions. The differences in knee function, particularly those during heel-strike which were associated with both age and disease severity, could form a basis for looking at mechanical risk factors for initiation and progression of knee OA on a prospective basis. PMID:24445065

  12. Influence of the lateral ventricles and irregular skull base on brain kinematics due to sagittal plane head rotation.

    PubMed

    Ivarsson, J; Viano, D C; Lövsund, P

    2002-08-01

    Two-dimensional physical models of the human head were used to investigate how the lateral ventricles and irregular skull base influence kinematics in the medial brain during sagittal angular head dynamics. Silicone gel simulated the brain and was separatedfrom the surrounding skull vessel by paraffin that provided a slip interface between the gel and vessel. A humanlike skull base model (HSB) included a surrogate skull base mimicking the irregular geometry of the human. An HSBV model added an elliptical inclusion filled with liquid paraffin simulating the lateral ventricles to the HSB model. A simplified skull base model (SSBV) included ventricle substitute but approximated the anterior and middle cranial fossae by a flat and slightly angled surface. The models were exposed to 7600 rad/s2 peak angular acceleration with 6 ms pulse duration and 5 deg forced rotation. After 90 deg free rotation, the models were decelerated during 30 ms. Rigid body displacement, shear strain and principal strains were determined from high-speed video recorded trajectories of grid markers in the surrogate brains. Peak values of inferior brain surface displacement and strains were up to 10.9X (times) and 3.3X higher in SSBV than in HSBV. Peak strain was up to 2.7X higher in HSB than in HSBV. The results indicate that the irregular skull base protects nerves and vessels passing through the cranial floor by reducing brain displacement and that the intraventricular cerebrospinal fluid relieves strain in regions inferior and superior to the ventricles. The ventricles and irregular skull base are necessary in modeling head impact and understanding brain injury mechanisms. PMID:12188208

  13. Ankle torque control that shifts the center of pressure from heel to toe contributes non-zero sagittal plane angular momentum during human walking.

    PubMed

    Gruben, Kreg G; Boehm, Wendy L

    2014-04-11

    A principle objective of human walking is controlling angular motion of the body as a whole to remain upright. The force of the ground on each foot (F) reflects that control, and recent studies show that in the sagittal plane F exhibits a specific coordination between F direction and center-of-pressure (CP) that is conducive to remaining upright. Typical walking involves the CP shifting relative to the body due to two factors: posterior motion of the foot with respect to the hip (stepping) and motion of the CP relative to the foot (foot roll-over). Recent research has also shown how adjusting ankle torque alone to shift CP relative to the foot systematically alters the direction of F, and thus, could play a key role in upright posture and the F measured during walking. This study explores how the CP shifts due to stepping and foot roll-over contribute to the observed F and its role in maintaining upright posture. Experimental walking kinetics and kinematics were combined with a mechanical model of the human to show that variation in F that was not attributable to foot roll-over had systematic correlation between direction and CP that could be described by an intersection point located near the center-of-mass. The findings characterize a component of walking motor control, describe how typical foot roll-over contributes to postural control, and provide a rationale for the increased fall risk observed in individuals with atypical ankle muscle function. PMID:24524989

  14. Kinematic and kinetic gait analysis in the sagittal plane of trans-femoral amputees before and after special gait re-education.

    PubMed

    Sjödahl, C; Jarnlo, G B; Söderberg, B; Persson, B M

    2002-08-01

    A special gait-training programme, combining a psychological therapeutic approach with methods in physiotherapy and body awareness, was used to re-educate nine unilateral trans-femoral amputees. All were rehabilitated trauma or tumour amputees with an age of 16-60 years. They had worn prostheses for more than 18 months. The re-education aimed at integrating the prosthesis in normal movements and increasing body awareness. Gait was measured before and after treatment and at 6 months follow-up with a three-dimensional motion analysis system. Results showed almost normalised gait speed and increased symmetry in the hip joints with increased muscle work on the amputated side both immediately and at follow-up. At follow-up there were significant differences in almost all parameters between the two legs of the subjects and when compared to a reference group of 18 healthy volunteers of similar age. Thus, the intact leg compensates for loss of function in the amputated leg and thereby works differently compared to the reference group. For example, during shock absorption the extension moment in the intact knee increased from 0.6 Nm/kg before to 1.0 Nm/kg after treatment and at follow-up compared to 0.4 Nm/kg in the reference group. The eccentric power of quadriceps increased from 0.6 w/kg before to 1.8 w/kg after treatment and 1.7 w/kg at follow-up compared to 0.4 w/kg in the reference group. The limp of amputees is usually observed in the frontal plane, but the authors' special focus on the sagittal plane here illustrates gait propulsion influences. The positive training results remained after six months. PMID:12227444

  15. Redefining the Boundaries of Interplanetary Coronal Mass Ejections from Observations at the Ecliptic Plane

    NASA Astrophysics Data System (ADS)

    Cid, C.; Palacios, J.; Saiz, E.; Guerrero, A.

    2016-09-01

    On 2015 January 6–7, an interplanetary coronal mass ejection (ICME) was observed at L1. This event, which can be associated with a weak and slow coronal mass ejection, allows us to discuss the differences between the boundaries of the magnetic cloud and the compositional boundaries. A fast stream from a solar coronal hole surrounding this ICME offers a unique opportunity to check the boundaries’ process definition and to explain differences between them. Using Wind and ACE data, we perform a complementary analysis involving compositional, magnetic, and kinematic observations providing relevant information regarding the evolution of the ICME as travelling away from the Sun. We propose erosion, at least at the front boundary of the ICME, as the main reason for the difference between the boundaries, and compositional signatures as the most precise diagnostic tool for the boundaries of ICMEs.

  16. Accuracy and repeatability of quantitative fluoroscopy for the measurement of sagittal plane translation and finite centre of rotation in the lumbar spine.

    PubMed

    Breen, Alexander; Breen, Alan

    2016-07-01

    Quantitative fluoroscopy (QF) was developed to measure intervertebral mechanics in vivo and has been found to have high repeatability and accuracy for the measurement of intervertebral rotations. However, sagittal plane translation and finite centre of rotation (FCR) are potential measures of stability but have not yet been fully validated for current QF. This study investigated the repeatability and accuracy of QF for measuring these variables. Repeatability was assessed from L2-S1 in 20 human volunteers. Accuracy was investigated using 10 consecutive measurements from each of two pairs of linked and instrumented dry human vertebrae as reference; one which tilted without translation and one which translated without tilt. The results found intra- and inter-observer repeatability for translation to be 1.1mm or less (SEM) with fair to substantial reliability (ICC 0.533-0.998). Intra-observer repeatability of FCR location for inter-vertebral rotations of 5° and above ranged from 1.5mm to 1.8mm (SEM) with moderate to substantial reliability (ICC 0.626-0.988). Inter-observer repeatability for FCR ranged from 1.2mm to 5.7mm, also with moderate to substantial reliability (ICC 0.621-0.878). Reliability was substantial (ICC>0.81) for 10/16 measures for translation and 5/8 for FCR location. Accuracy for translation was 0.1mm (fixed centre) and 2.2mm (moveable centre), with an FCR error of 0.3mm(x) and 0.4mm(y) (fixed centre). This technology was found to have a high level of accuracy and with a few exceptions, moderate to substantial repeatability for the measurement of translation and FCR from fluoroscopic motion sequences. PMID:27129784

  17. Effects of mid-foot contact area ratio on lower body kinetics/kinematics in sagittal plane during stair descent in women.

    PubMed

    Lee, Jinkyu; Hong, Yoon No Gregory; Shin, Choongsoo S

    2016-07-01

    The mid-foot contact area relative to the total foot contact area can facilitate foot arch structure evaluation. A stair descent motion consistently provides initial fore-foot contact and utilizes the foot arch more actively for energy absorption. The purpose of this study was to compare ankle and knee joint angle, moment, and work in sagittal plane during stair descending between low and high Mid-Foot-Contact-Area (MFCA) ratio group. The twenty-two female subjects were tested and classified into two groups (high MFCA and low MFCA) using their static MFCA ratios. The ground reaction force (GRF) and kinematics of ankle and knee joints were measured while stair descending. During the period between initial contact and the first peak in vertical GRF (early absorption phase), ankle negative work for the low MFCA ratio group was 33% higher than that for the high MFCA ratio group (p<0.05). However, ankle negative work was not significantly different between the two groups during the period between initial contact and peak dorsiflexion angle (early absorption phase+late absorption phase). The peak ankle dorsiflexion angle was smaller in the low MFCA ratio group (p<0.05). Our results suggest that strategy of energy absorption at the ankle and foot differs depending upon foot arch types classified by MFCA. The low MFCA ratio group seemed to absorb more impact energy using strain in the planar fascia during early absorption phase, whereas the high MFCA ratio group absorbed more impact energy using increased dorsiflexion during late absorption phase. PMID:27477715

  18. Virtual preoperative measurement and surgical manipulation of sagittal spinal alignment using a novel research and educational software program.

    PubMed

    Pettigrew, David B; Morgan, Chad J; Anderson, R Brian; Wilsey, Philip A; Kuntz, Charles

    2010-03-01

    Understanding regional as well as global spinal alignment is increasingly recognized as important for the spine surgeon. A novel software program for virtual preoperative measurement and surgical manipulation of sagittal spinal alignment was developed to provide a research and educational tool for spine surgeons. This first-generation software program provides tools to measure sagittal spinal alignment from the occiput to the pelvis, and to allow for virtual surgical manipulation of sagittal spinal alignment. The software was developed in conjunction with Clifton Labs, Inc. Photographs and radiographs were imported into the software program, and a 2D virtual spine was constructed from the images. The software then measured regional and global sagittal spinal alignment from the virtual spine construct, showing the user how to perform the measurements. After measuring alignment, the program allowed for virtual surgical manipulation, simulating surgical procedures such as interbody fusion, facet osteotomy, pedicle subtraction osteotomy, and reduction of spondylolisthesis, as well as allowing for rotation of the pelvis on the hip axis. Following virtual manipulation, the program remeasured regional and global sagittal spinal alignment. Computer software can be used to measure and manipulate sagittal spinal alignment virtually, providing a new research and educational tool. In the future, more comprehensive programs may allow for measurement and interaction in the coronal, axial, and sagittal planes. PMID:20192663

  19. A portable system with sample rate of 250 Hz for characterization of knee and hip angles in the sagittal plane during gait

    PubMed Central

    2014-01-01

    Background Gait analysis and research have been developed to obtain characteristics of movement patterns of people while walking. However, traditional measuring systems present different drawbacks that reduce their use and application. Among those drawbacks one can find: high price, low sampling frequency and limiting number of steps to be analyzed. Traditional measuring gait systems carry out their measurement at frequencies oscillating between 60 to 100 Hz. It can be argued about the need of higher sampling rates for gait measurements. However small displacements of the knee or hip for example, cannot be seen with low frequencies required a more detailed sampling and higher frequency sampling. Bearing this in mind, in this paper is presented a 250 Hz system based on accelerometers for gait measurement, and the particularities of knee and hip angles during gait are highlighted. Methods The system was designed with a PCI data acquisition card instrumented with an FPGA to achieve a rate sample of 250 Hz. The accelerometers were placed in thighs and legs to calculate the joint angles of hip and knee in the sagittal plane. The angles were estimated using the acceleration polygon method without integrating the acceleration and without filters. Results The gait of thirty healthy people of Mexican phenotype was analyzed over a flat floor free of obstacles. The results showed the gait phases and particularities associated with the walking style and people's laterality; the movement patterns were similar in the thirty persons. Based on the results, the particularities as the maximum amplitude in the angles and the shape in the movement patterns were related to the anthropometry and people phenotype. Conclusions The sampling frequency was essential to record 340 samples in single gait cycle and so registering the gait cycle with its particularities. In this work were recorded an average of 8 to 10 gait cycles, and the results showed variation regarding works carried out

  20. Correction of coronal plane deformities around the knee using a tension band plate in children younger than 10 years

    PubMed Central

    Kulkarni, Ruta M; Ilyas Rushnaiwala, Faizaan M; Kulkarni, GS; Negandhi, Rajiv; Kulkarni, Milind G; Kulkarni, Sunil G

    2015-01-01

    Background: Guided growth through temporary hemiepiphysiodesis has gained acceptance as the preferred primary treatment in treating pediatric lower limb deformities as it is minimally invasive with a lesser morbidity than the traditional osteotomy. The tension band plate is the most recent development in implants used for temporary hemiepiphysiodesis. Our aim was to determine its safety and efficacy in correcting coronal plane deformities around the knee in children younger than 10 years. Materials and Methods: A total of 24 children under the age of 10 were operated for coronal plane deformities around the knee with a single extra periosteal tension band plate and two nonlocking screws. All the children had a pathological deformity for which a detailed preoperative work-up was carried out to ascertain the cause of the deformity and rule out physiological ones. The average age at hemiepiphysiodesis was 5 years 3 months (range: 2 years to 9 years 1 month). Results: The plates were inserted for an average of 15.625 months (range: 7 months to 29 months). All the patients showed improvement in the mechanical axis. Two patients showed partial correction. Two cases of screw loosening were observed. In the genu valgum group, the tibiofemoral angle improved from a preoperative mean of 19.89° valgus (range: 10° valgus to 40° valgus) to 5.72° valgus (range: 2° varus to 10° valgus). In patients with genu varum the tibiofemoral angle improved from a mean of 28.27° varus (range: 13° varus to 41° varus) to 1.59° valgus (range: 0-8° valgus). Conclusion: Temporary hemiepiphysiodesis through the application of the tension band plate is an effective method to correct coronal plane deformities around the knee with minimal complications. Its ease and accuracy of insertion has extended the indication of temporary hemiepiphysiodesis to patients younger than 10 years and across a wide variety of diagnosis including pathological physis, which were traditionally out of the

  1. Approximation of the functional kinematics of posterior stabilised total knee replacements using a two-dimensional sagittal plane patello-femoral model: comparing model approximation to in vivo measurement.

    PubMed

    Van Duren, Bernard; Pandit, Hemant; Murray, David; Gill, Harinderjit

    2015-08-01

    Previous in vivo studies have observed that current designs of posterior stabilised (PS) total knee replacements (TKRs) may be ineffective in restoring normal kinematics in Late flexion. Computer-based models can prove a useful tool in improving PS knee replacement designs. This study investigates the accuracy of a two-dimensional (2D) sagittal plane model capable of predicting the functional sagittal plane kinematics of PS TKR implanted knees against direct in vivo measurement. Implant constraints are often used as determinants of anterior-posterior tibio-femoral positioning. This allowed the use of a patello-femoral modelling approach to determine the effect of implant constraints. The model was executed using motion simulation software which uses the constraint force algorithm to achieve a solution. A group of 10 patients implanted with Scorpio PS implants were recruited and underwent fluoroscopic imaging of their knees. The fluoroscopic images were used to determine relative implant orientation using a three-dimensional reconstruction method. The determined relative tibio-femoral orientations were then input to the model. The model calculated the patella tendon angles (PTAs) which were then compared with those measured from the in vivo fluoroscopic images. There were no significant differences between the measured and calculated PTAs. The average root mean square error between measured and modelled ranged from 1.17° to 2.10° over the flexion range. A sagittal plane patello-femoral model could conceivably be used to predict the functional 2D kinematics of an implanted knee joint. This may prove particularly useful in optimising PS designs. PMID:24559039

  2. The effect of medial meniscectomy and coronal plane angulation on in vitro load transmission in the canine stifle joint.

    PubMed

    Newman, A P; Anderson, D R; Daniels, A U; Jee, K W

    1989-01-01

    The purpose of this study was to determine the in vitro load transmission characteristics of the canine stifle joint, paying particular attention to the positioning effect of the meniscus in the coronal plane. The intact joint was first loaded, and then tested under two different loading conditions after a complete medial meniscectomy. The first set of test conditions attempted to simulate those used by previous investigators, by ignoring the spacer effect of the meniscus and not repositioning the joint after its removal. The second set of tests was carried out after the joint was repositioned in the coronal plane to allow initial contact to occur in both tibiofemoral compartments. It is presumed that this occurs subsequent to a meniscectomy in vivo, following the application of any weight-bearing load. As with previous investigators, it was found that after meniscectomy the joints produced slightly larger displacements and lower stiffnesses than when intact (no significant differences from intact). However, repositioning the meniscectomized joint produced markedly smaller displacements (35-49%, p less than 0.01) and greater stiffnesses (47-123%, p less than 0.05) over the range of forces analyzed, compared with the intact joint. The ratio of dissipated to input energy was 42% for the intact joint, and rose following meniscectomy to 54% (p less than 0.05) with repositioning and 55% (p less than 0.05) without repositioning. Measured contact area decreased by 17% (p less than 0.05) following meniscectomy alone, and by 12% (p less than 0.05) following meniscectomy with repositioning. Since repositioning of the joint subsequent to meniscectomy (accounting for the loss of the meniscal spacer) resulted in an increase in structural stiffness, it was concluded that the medial meniscus decreases the structural stiffness of the intact stifle joint. In addition, the meniscus has a role in elastic energy storage and increasing contact area. This study is intended to serve as a

  3. Direct oblique sagittal CT of orbital wall fractures

    SciTech Connect

    Ball, J.B. Jr.

    1987-03-01

    Direct oblique sagittal CT was used to evaluate trauma to 77 orbits. Sixty-seven orbital wall fractures with intact orbital rims (36 floor, 22 medial wall, nine roof) were identified in 47 orbits. Since persistent diplopia and/or enophthalmos may warrant surgical repair of orbital floor fractures, optimal imaging should include an evaluation of extraocular muscle status, the nature and amount of displaced orbital contents, and an accurate definition of fracture margins. For orbital floor fractures, a combination of the direct oblique sagittal and direct coronal projections optimally displayed all fracture margins, the fracture's relationship to the inferior orbital rim and medial orbital wall, and the amount of displacement into the maxillary sinus. Inferior rectus muscle status with 36 floor fractures was best seen on the direct oblique sagittal projection in 30 fractures (83.3%) and was equally well seen on sagittal and coronal projections in two fractures (5.5%). Floor fractures were missed on 100% of axial, 5.5% of sagittal, and 0% of coronal projections. Since the direct oblique sagittal projection complements the direct coronal projection in evaluating orbital floor fractures, it should not be performed alone. A technical approach to the CT evaluation or orbital wall fractures is presented.

  4. The Immediate Post-Operative Radiograph is an Unreliable Measure of Coronal Plane Alignment in Total Knee Replacement

    PubMed Central

    Petterwood, Joshua; Dowsey, Michelle M.; Rodda, Daevyd; Choong, Peter F. M.

    2014-01-01

    Background: Restoration of a neutral mechanical axis is a primary goal of total knee replacement (TKR). A mechanical axis within 3° of neutral has been correlated with improved implant longevity, function, and patient satisfaction. We hypothesize that the immediate post-operative radiograph is an unreliable method of measuring alignment following TKR surgery. Methods: Seventy-five consecutive patients had supine X-rays performed on day two post-operatively followed by standing long-leg radiographs (LLRs) 6 weeks post-operatively. Correlation was sought between the mechanical axis measured on the LLR and surrogate markers of alignment on the post-operative X-ray including component alignment and an estimation of anatomical alignment using the available length of femoral and tibial shafts. Inter- and intra-observer reliabilities were assessed. Results: The mean mechanical axis on the LLR was 180.5 (SD 3.0, range 175.1–187.1). Mean offset between anatomical axis and mechanical axis was 6.4°. The mean anatomical axis measured on the short-leg X-ray was 174.9 (SD 2.4, range 169.5–181.3). Mechanical axis on the LLR was compared to the anatomical axis measured on the short-leg radiograph (SLR) + 6° with an interclass correlation coefficient of 0.588 (p < 0.001). The level of disagreement between the short- and long-leg X-rays was assessed using the Bland–Altman method and demonstrated clinically important discrepancies of 5 or more degrees in 9% of cases. Inter- and intra-observer agreements were high on all measures (p < 0.001). Conclusion: The long-leg weight bearing X-ray is an essential tool to accurately assess coronal plane alignment post TKR. While the immediate post-operative X-ray taken supine provides useful information to the surgeon on any immediate complications, our results indicate that it cannot be relied upon to determine correct restoration of the mechanical axis. PMID:25593959

  5. High oblique sagittal split osteotomy of the mandible: assessment of the positions of the mandibular condyles after orthognathic surgery based on cone-beam tomography.

    PubMed

    Kuehle, R; Berger, M; Saure, D; Hoffmann, J; Seeberger, R

    2016-07-01

    High oblique sagittal split osteotomy is an orthognathic technique to move the mandible. Our aim was to evaluate changes in the position of the condyle in the glenoid fossa and its angulation before and after high oblique sagittal split osteotomy (HSSO). Fifty patients (32 women and 18 men, mean age 26.3 (SD 7.4) years) had cone-beam computed tomographyic (CT) scans before operation, immediately postoperatively, and before removal of the osteosynthesis nine months postoperatively. The images were analysed to look for changes in the sagittal, coronal, and axial positions of the condyles. Twenty-four patients with class II malocclusion had a mean (SD) mandibular advancement of 6.51 (2.41) mm, and 26 patients with class III malocclusion had a mean (SD) mandibular setback of 4.16 (2.77) mm. The joint space increased significantly (p<0.05) relative to baseline immediately postoperatively, but there was no significant increase at the nine-month follow-up. The changes in position in the sagittal, coronal, and axial planes were comparable. Despite there being a short proximal joint-bearing segment, the results indicate that this technique allows free-hand condylar positioning into the fossa safely without any clinically relevant dislocations. PMID:27050098

  6. Radiographic Parameters in Adult Degenerative Scoliosis and Different Parameters Between Sagittal Balanced and Imbalanced ADS Patients

    PubMed Central

    Yang, Changwei; Yang, Mingyuan; Chen, Yuanyuan; Wei, Xianzhao; Ni, Haijian; Chen, Ziqiang; Li, Jingfeng; Bai, Yushu; Zhu, Xiaodong; Li, Ming

    2015-01-01

    Abstract A retrospective study. To summarize and describe the radiographic parameters of adult degenerative scoliosis (ADS) and explore the radiological parameters which are significantly different in sagittal balanced and imbalanced ADS patients. ADS is the most common type of adult spinal deformity. However, no comprehensive description of radiographic parameters in ADS patients has been made, and few studies have been performed to explore which radiological parameters are significantly different between sagittal balanced and imbalanced ADS patients. Medical records of ADS patients in our outpatient clinic from January 2012 to January 2014 were reviewed. Demographic data including age and sex, and radiographic data including the coronal Cobb angle, location of apical vertebra/disc, convexity of the curve, degree of apical vertebra rotation, curve segments, thoracic kyphosis (TK), lumbar lordosis (LL), thoracolumbar kyphosis (TL), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), sagittal vertical axis (SVA), and PI minus LL (PI − LL) were reviewed to make comprehensive description of radiographic parameters of ADS. Furthermore, patients were divided into 2 groups according to whether the patients’ sagittal plane was balanced: Group A (imbalanced, SVA > 5 cm) and Group B (balanced, SVA ≤ 5 cm). Demographic and radiological parameters were compared between these 2 groups. A total of 99 patients were included in this study (Group A = 33 and Group B = 66; female = 83 and male = 16; sex ratio = 5:1). The median of age were 67 years (range: 41–92 years). The median of coronal Cobb angle and length of curve was 23 (range: 10–75°) and 5 segments (range: 3–7), respectively. The most common location of apical vertebra was at L2 to L3 (81%) and the median of degree of apical vertebra rotation was 2° (range: 1–3). Our study also showed significant correlations between coronal Cobb angle and curve segments (r

  7. The relationships between the center of mass position and the trunk, hip, and knee kinematics in the sagittal plane: a pilot study on field-based video analysis for female soccer players.

    PubMed

    Sasaki, Shogo; Nagano, Yasuharu; Kaneko, Satoshi; Imamura, Shoichiro; Koabayshi, Takuma; Fukubayashi, Toru

    2015-03-29

    Athletes with non-contact anterior cruciate ligament tears have common features in the sagittal plane; namely, the body's center of mass (COM) is located posterior to the base of support, the trunk and knee joints are extended, and the hip angle is flexed. However, the relationships among these variables have not been assessed in field-based movements. This study sought to determine relationships between distances from the COM to the base of support and the trunk, hip, and knee positions in women while playing soccer. Sixty events (29 single-leg landing and 31 single-leg stopping events) were analyzed using two-dimensional video analysis. The relationships among the measurement variables were determined using the Pearson's product-moment correlation coefficient, and stepwise multiple linear regression models were used to explore the relationships between the COM position and the kinematic variables. The distance from the COM to the base of support displayed a moderate negative relationship with the trunk angle (r = -0.623, p < .0001, r(2) = 0.388) and a strong positive relationship with the limb angle (r = 0.869, p < .0001, r(2) = 0.755). The limb, knee, and trunk angles were selected in the best regression model (adjusted r(2) = 0.953, p < .0001, f(2) = 20.277). These findings suggest that an increased trunk angle and a decreased limb angle at initial contact are associated with a safer COM position. Neuromuscular training may be useful for controlling the trunk and lower limb positions during dynamic activities. PMID:25964811

  8. Examination of Inertial Sensor-Based Estimation Methods of Lower Limb Joint Moments and Ground Reaction Force: Results for Squat and Sit-to-Stand Movements in the Sagittal Plane.

    PubMed

    Kodama, Jun; Watanabe, Takashi

    2016-01-01

    Joint moment estimation by a camera-based motion measurement system and a force plate has a limitation of measurement environment and is costly. The purpose of this paper is to evaluate quantitatively inertial sensor-based joint moment estimation methods with five-link, four-link and three-link rigid body models using different trunk segmented models. Joint moments, ground reaction forces (GRF) and center of pressure (CoP) were estimated for squat and sit-to-stand movements in the sagittal plane measured with six healthy subjects. The five-link model and the four-link model that the trunk was divided at the highest point of the iliac crest (four-link-IC model) were appropriate for joint moment estimation with inertial sensors, which showed average RMS values of about 0.1 Nm/kg for all lower limb joints and average correlation coefficients of about 0.98 for hip and knee joints and about 0.80 for ankle joint. Average root mean square (RMS) errors of horizontal and vertical GRFs and CoP were about 10 N, 15 N and 2 cm, respectively. Inertial sensor-based method was suggested to be an option for estimating joint moments of the trunk segments. Inertial sensors were also shown to be useful for the bottom-up estimation method using measured GRFs, in which average RMS values and average correlation coefficients were about 0.06 Nm/kg and larger than about 0.98 for all joints. PMID:27490544

  9. The Relationships Between the Center of Mass Position and the Trunk, Hip, and Knee Kinematics in the Sagittal Plane: A Pilot Study on Field-Based Video Analysis for Female Soccer Players

    PubMed Central

    Sasaki, Shogo; Nagano, Yasuharu; Kaneko, Satoshi; Imamura, Shoichiro; Koabayshi, Takuma; Fukubayashi, Toru

    2015-01-01

    Athletes with non-contact anterior cruciate ligament tears have common features in the sagittal plane; namely, the body’s center of mass (COM) is located posterior to the base of support, the trunk and knee joints are extended, and the hip angle is flexed. However, the relationships among these variables have not been assessed in field-based movements. This study sought to determine relationships between distances from the COM to the base of support and the trunk, hip, and knee positions in women while playing soccer. Sixty events (29 single-leg landing and 31 single-leg stopping events) were analyzed using two-dimensional video analysis. The relationships among the measurement variables were determined using the Pearson’s product-moment correlation coefficient, and stepwise multiple linear regression models were used to explore the relationships between the COM position and the kinematic variables. The distance from the COM to the base of support displayed a moderate negative relationship with the trunk angle (r = −0.623, p < .0001, r2 = 0.388) and a strong positive relationship with the limb angle (r = 0.869, p < .0001, r2 = 0.755). The limb, knee, and trunk angles were selected in the best regression model (adjusted r2 = 0.953, p < .0001, f2 = 20.277). These findings suggest that an increased trunk angle and a decreased limb angle at initial contact are associated with a safer COM position. Neuromuscular training may be useful for controlling the trunk and lower limb positions during dynamic activities. PMID:25964811

  10. CORONAL CELLS

    SciTech Connect

    Sheeley, N. R. Jr.; Warren, H. P. E-mail: harry.warren@nrl.navy.mil

    2012-04-10

    We have recently noticed cellular features in Fe XII 193 A images of the 1.2 MK corona. They occur in regions bounded by a coronal hole and a filament channel, and are centered on flux elements of the photospheric magnetic network. Like their neighboring coronal holes, these regions have minority-polarity flux that is {approx}0.1-0.3 times their flux of majority polarity. Consequently, the minority-polarity flux is 'grabbed' by the majority-polarity flux to form low-lying loops, and the remainder of the network flux escapes to connect with its opposite-polarity counterpart in distant active regions of the Sun. As these regions are carried toward the limb by solar rotation, the cells disappear and are replaced by linear plumes projecting toward the limb. In simultaneous views from the Solar Terrestrial Relations Observatory and Solar Dynamics Observatory spacecraft, these plumes project in opposite directions, extending away from the coronal hole in one view and toward the hole in the other view, suggesting that they are sky-plane projections of the same radial structures. We conclude that these regions are composed of closely spaced radial plumes, extending upward like candles on a birthday cake and visible as cells when seen from above. We suppose that a coronal hole has this same discrete, cellular magnetic structure, but that it is not seen until the encroachment of opposite-polarity flux closes part or all of the hole.

  11. Bilateral Sagittal Split Osteotomy

    PubMed Central

    Monson, Laura A.

    2013-01-01

    The bilateral sagittal split osteotomy is an indispensable tool in the correction of dentofacial abnormalities. The technique has been in practice since the late 1800s, but did not reach widespread acceptance and use until several modifications were described in the 1960s and 1970s. Those modifications came from a desire to make the procedure safer, more reliable, and more predictable with less relapse. Those goals continue to stimulate innovation in the field today and have helped the procedure evolve to be a very dependable, consistent method of correction of many types of malocclusion. The operative surgeon should be well versed in the history, anatomy, technical aspects, and complications of the bilateral sagittal split osteotomy to fully understand the procedure and to counsel the patient. PMID:24872760

  12. MRI to delineate the gross tumor volume of nasopharyngeal cancers: which sequences and planes should be used?

    PubMed Central

    Popovtzer, Aron; Ibrahim, Mohannad; Tatro, Daniel; Feng, Felix Y.; Ten Haken, Randall K.; Eisbruch, Avraham

    2014-01-01

    Background Magnetic resonance imaging (MRI) has been found to be better than computed tomography for defining the extent of primary gross tumor volume (GTV) in advanced nasopharyngeal cancer. It is routinely applied for target delineation in planning radiotherapy. However, the specific MRI sequences/planes that should be used are unknown. Methods Twelve patients with nasopharyngeal cancer underwent primary GTV evaluation with gadolinium-enhanced axial T1 weighted image (T1) and T2 weighted image (T2), coronal T1, and sagittal T1 sequences. Each sequence was registered with the planning computed tomography scans. Planning target volumes (PTVs) were derived by uniform expansions of the GTVs. The volumes encompassed by the various sequences/planes, and the volumes common to all sequences/planes, were compared quantitatively and anatomically to the volume delineated by the commonly used axial T1-based dataset. Results Addition of the axial T2 sequence increased the axial T1-based GTV by 12% on average (p = 0.004), and composite evaluations that included the coronal T1 and sagittal T1 planes increased the axial T1-based GTVs by 30% on average (p = 0.003). The axial T1-based PTVs were increased by 20% by the additional sequences (p = 0.04). Each sequence/plane added unique volume extensions. The GTVs common to all the T1 planes accounted for 38% of the total volumes of all the T1 planes. Anatomically, addition of the coronal and sagittal-based GTVs extended the axial T1-based GTV caudally and cranially, notably to the base of the skull. Conclusions Adding MRI planes and sequences to the traditional axial T1 sequence yields significant quantitative and anatomically important extensions of the GTVs and PTVs. For accurate target delineation in nasopharyngeal cancer, we recommend that GTVs be outlined in all MRI sequences/planes and registered with the planning computed tomography scans. PMID:25177248

  13. [Short sagittal osteotomy].

    PubMed

    Paulus, Christian; Kater, Wolfgang

    2015-12-01

    Bilateral sagittal split osteotomy has become the standard mandibular surgery for the treatment of dento-facial deformities. Even patients with less important deformities may undergo surgery. The morbidity must be as low as possible. We describe a technique with reduced split surfaces. The osseous section follows an oblique line since the thorn of Spix below and outside towards the supra-angular region. This section is completed by an osteotomy of the posterior border of the mandible. This split never reaches the inferior alveolar nerf tunnel. The protection of the alveolar nerve is increased what decreases considerably the risk of nervous complications of this intervention. The majority of the mandibular movements are possible by this technique with the exception of the important advancements and the increase of the height of the ramus. PMID:26655415

  14. Ten-Year Results of Primary and Revision Condylar-Constrained Total Knee Arthroplasty in Patients with Severe Coronal Plane Instability

    PubMed Central

    Camera, Andrea; Biggi, Stefano; Cattaneo, Gabriele; Brusaferri, Giovanni

    2015-01-01

    Objective : To retrospectively review the results at minimum ten years after surgery of a consecutive series of total knee arthroplasties (TKAs) performed using a constrained condylar implant in patients with severe coronal plane instability. Materials and Methods : The series comprised of 44 patients (45 knees) who received primary (19 knees) or revision (26 knees) TKA with a constrained condylar implant between 2001 and 2003 at a single institution. Results : There were no revisions or any other surgery related complications at a mean implantation time of 11.0 years. In 38 patients (15 knees in the primary group and 24 knees in the revision group) who were available for clinico-radiographic follow-up at a minimum of ten years, there was no sign of radiographic loosening. Two patients showed cortical hypertrophy at the extension stem tip but none complained of pain around the stem tip. According to the TLKSS score grading, 73% of the patients in the primary group had results categorized as good or excellent, while 54% of the patients in the revision group had fair results. Four patients (one (7%) in the primary group and three (13%) in the revision group) had poor results. The median WOMAC Index was 80.2% (interquartile range: 74.0% - 81.2%) and 74.0% (interquartile range: 72.1% - 75.8%) in the primary and in the revision groups, respectively (p=0.010). Conclusion : This study showed satisfactory clinical outcomes with no re-operations at minimum ten years after implantation in patients who had undergone primary or revision TKA with a condylar constrained implant. PMID:26401160

  15. Superior Sagittal Sinus Thrombosis

    PubMed Central

    Nakase, Hiroyuki; Takeshima, Toshikazu; Sakaki, Toshisuke; Heimann, Axel; Kempski, Oliver

    1998-01-01

    Sinus-vein thrombosis is increasingly recognized as a much more frequent neurological disorder than was anticipated before. We examined the pathophysiology of superior sagittal sinus thrombosis (SSST) from 19 patients and a rat SSST model. We treated 19 cases with SSST who were diagnosed by angiography. The symptoms of nine patients, who suffered multiple intracerebral hemorrhage, were abrupt. In another ten patients who recovered satisfactorily, the condition progressed slowly and they were treated with heparin and urokinase. Multivariate analysis demonstrated that female, sudden onset (<24 hours) and posterior 1/3 occlusion are related to bad outcome. Experimentally, SSST was induced by ligation and slow injection of kaolin-cephalin suspension into SSS in rats. Regional cerebral blood flow (rCBF) and tissue hemoglobin oxygen saturation (Hb Sao2) using a “scanning” technique were measured at 48 locations, and fluorescence angiography was performed before and until 90 min after SSST induction. After 48 hours the animals were sacrificed for histological studies. Decrease of rCBF and tissue Hb SO2 and brain damage were seen in group B (n = 10) with an extension of thrombosis from SSS into cortical veins. Brain injury was not observed in group A (n = 8) with SSS thrombus alone and sham-operated animals (n = 5). In conclusion, a brain with acute extension of thrombus from SSS into cortical veins becomes critical for cerebral blood supply and metabolism. CBF, tissue HbSO2 and repeated angiography can be helpful monitors for the early detection of critical conditions after SSST. As to the therapy, restraint on the ongoing thrombus is essential to protect the brain with SSST, and we encourage the use of combination therapy of heparin and urokinase as early as possible in cases without intracerebral hemorrhage. ImagesFigure 1Figure 2 PMID:17171061

  16. ARTICULATOR-RELATED REGISTRATION AND ANALYSIS OF SAGITTAL CONDYLAR INCLINATION.

    PubMed

    Cimić, Samir; Simunković, Sonja Kraljević; Suncana Simonić Kocijan; Matijević, Jurica; Dulcić, Niksa; Catić, Amir

    2015-12-01

    The purpose of this investigation was to study sagittal condylar inclination values within a uniform sample (Angle class I occlusion) using 'articulator-related registration' and Camper's plane as a reference plane. The study was performed on a sample of 58 Angle class I subjects (mean age 25.1, SD 3.1). Measurements were performed with an ultrasonic jaw tracking device with six degrees of freedom. After a paraocclusal tray was fixed in the mouth, each subject had to make three protrusive movements and three right and left laterotrusive movements. From protrusive movements the software of the device automatically calculated the left and the right sagittal condylar inclination values used for setting of the articulator. The mean sagittal condylar inclinationvalue was 41.0° (SD 10.5) for the right joint and 40.7° (SD 9.8) for the left joint. The maximum value was 65.0° for the right and 68.6° for the left joint, and the minimum value was 13.7° for the right and 21.7° for the left joint. The results of this study suggested the average articulator setting for sagittal condylar inclination for fully dentate adult subjects to be 40° in relation to Camper's plane. This is especially important for the articulators that are set up in relation to Camper's plane. PMID:27017716

  17. Automatic Recognition of Fetal Facial Standard Plane in Ultrasound Image via Fisher Vector

    PubMed Central

    Lei, Baiying; Tan, Ee-Leng; Chen, Siping; Zhuo, Liu; Li, Shengli; Ni, Dong; Wang, Tianfu

    2015-01-01

    Acquisition of the standard plane is the prerequisite of biometric measurement and diagnosis during the ultrasound (US) examination. In this paper, a new algorithm is developed for the automatic recognition of the fetal facial standard planes (FFSPs) such as the axial, coronal, and sagittal planes. Specifically, densely sampled root scale invariant feature transform (RootSIFT) features are extracted and then encoded by Fisher vector (FV). The Fisher network with multi-layer design is also developed to extract spatial information to boost the classification performance. Finally, automatic recognition of the FFSPs is implemented by support vector machine (SVM) classifier based on the stochastic dual coordinate ascent (SDCA) algorithm. Experimental results using our dataset demonstrate that the proposed method achieves an accuracy of 93.27% and a mean average precision (mAP) of 99.19% in recognizing different FFSPs. Furthermore, the comparative analyses reveal the superiority of the proposed method based on FV over the traditional methods. PMID:25933215

  18. Automatic Recognition of Fetal Facial Standard Plane in Ultrasound Image via Fisher Vector.

    PubMed

    Lei, Baiying; Tan, Ee-Leng; Chen, Siping; Zhuo, Liu; Li, Shengli; Ni, Dong; Wang, Tianfu

    2015-01-01

    Acquisition of the standard plane is the prerequisite of biometric measurement and diagnosis during the ultrasound (US) examination. In this paper, a new algorithm is developed for the automatic recognition of the fetal facial standard planes (FFSPs) such as the axial, coronal, and sagittal planes. Specifically, densely sampled root scale invariant feature transform (RootSIFT) features are extracted and then encoded by Fisher vector (FV). The Fisher network with multi-layer design is also developed to extract spatial information to boost the classification performance. Finally, automatic recognition of the FFSPs is implemented by support vector machine (SVM) classifier based on the stochastic dual coordinate ascent (SDCA) algorithm. Experimental results using our dataset demonstrate that the proposed method achieves an accuracy of 93.27% and a mean average precision (mAP) of 99.19% in recognizing different FFSPs. Furthermore, the comparative analyses reveal the superiority of the proposed method based on FV over the traditional methods. PMID:25933215

  19. Modeling posture-dependent leg actuation in sagittal plane locomotion.

    PubMed

    Schmitt, J; Clark, J

    2009-12-01

    The spring loaded inverted pendulum template has been shown to accurately model the steady locomotion dynamics of a variety of running animals, and has served as the inspiration for an entire class of dynamic running robots. While the template models the leg dynamics by an energy-conserving spring, insects and animals have structures that dissipate, store and produce energy during a stance phase. Recent investigations into the spring-like properties of limbs, as well as animal response to drop-step perturbations, suggest that animals use their legs to manage energy storage and dissipation, and that this management is important for gait stability. In this paper, we extend our previous analysis of control of the spring loaded inverted pendulum template via changes in the leg touch-down angle to include energy variations during the stance phase. Energy variations are incorporated through leg actuation that varies the force-free leg length during the stance phase, yet maintains qualitatively correct force and velocity profiles. In contrast to the partially asymptotically stable gaits identified in previous analyses, incorporating energy and leg angle variations in this manner produces complete asymptotic stability. Drop-step perturbation simulations reveal that the control strategy is rather robust, with gaits recovering from drops of up to 30% of the nominal hip height. PMID:19946148

  20. Standardized way for imaging of the sagittal spinal balance.

    PubMed

    Morvan, Gérard; Mathieu, Philippe; Vuillemin, Valérie; Guerini, Henri; Bossard, Philippe; Zeitoun, Frédéric; Wybier, Marc

    2011-09-01

    Nowadays, conventional or digitalized teleradiography remains the most commonly used tool for the study of the sagittal balance, sometimes with secondary digitalization. The irradiation given by this technique is important and the photographic results are often poor. Some radiographic tables allow the realization of digitalized spinal radiographs by simultaneous translation of X-ray tube and receptor. EOS system is a new, very low dose system which gives good quality images, permits a simultaneous acquisition of upright frontal and sagittal views, is able to cover in the same time the spine and the lower limbs and study the axial plane on 3D envelope reconstructions. In the future, this low dose system should take a great place in the study of the pelvispinal balance. On the lateral view, several pelvic (incidence, pelvic tilt, sacral slope) and spinal (lumbar lordosis, thoracic kyphosis, Th9 sagittal offset, C7 plumb line) parameters are drawn to define the pelvispinal balance. All are interdependent. Pelvic incidence is an individual anatomic characteristic that corresponds to the "thickness" of the pelvis and governs the spinal balance. Pelvis and spine, in a harmonious whole, can be compared to an accordion, more or less compressed or stretched. PMID:21830081

  1. Properties and Radial Trends of Coronal Mass Ejecta and Their Associated Shocks Observed by Ulysses in the Ecliptic Plane. Appendix 2; Repr. from Journal of Geophysical Research, v. 105, 2000 p 12,617-12,626

    NASA Technical Reports Server (NTRS)

    Riley, Pete; Gosling, J. T.; McComas, D. J.; Forsyth, R. J.

    2001-01-01

    In this paper, magnetic and plasma measurements are used to analyze 17 interplanetary coronal mass ejections (CMEs) identified by Ulysses during its in-ecliptic passage to Jupiter. We focus on the expansion characteristics of these CMEs (as inferred from the time rate of change of the velocity profiles through the CMEs) and the properties of 14 forward shocks unambiguously associated with these CMEs. We highlight radial trends from 1 to 5.4 AU. Our results indicate that the CMEs are generally expanding at all heliocentric distances. With regard to the shocks preceding these ejecta, we note the following: (1) There is a clear tendency for the shock speed (in the upstream frame of reference) to decrease with increasing heliocentric distance as the CMEs transfer momentum to the ambient solar wind and slow down; (2) 86% of the shock fronts are oriented in the ecliptic plane such that their normals point westward (i.e., in the direction of planetary motion about the Sun), (3) 86% of the shocks are propagating toward the heliographic equator; and (4) no clear trend was found in the strength of the shocks versus heliocentric distance. These results are interpreted using simple dynamical arguments and are supported by fluid and magnetohydrodynamic (MHD) simulations.

  2. Superior sagittal sinus thrombosis. Still a killer.

    PubMed Central

    Schell, C L; Rathe, R J

    1988-01-01

    Following treating a case of superior sagittal sinus thrombosis, we did an extensive search of the literature, eliciting 795 cases of the disorder. An analysis showed that even after the introduction of antibiotics, the preponderance of these cases have been diagnosed at autopsy. Our findings raise questions about the current methods of diagnosis and management of superior sagittal sinus thrombosis: Can the correct diagnosis be made earlier? Does a distinction between partial and complete thrombosis call for a different management? Images PMID:3051676

  3. Coronal and Prominence Plasmas

    NASA Technical Reports Server (NTRS)

    Poland, Arthur I. (Editor)

    1986-01-01

    Various aspects of solar prominences and the solar corona are discussed. The formation of prominences, prominence diagnostics and structure, prominence dissappearance, large scale coronal structure, coronal diagnostics, small scale coronal structure, and non-equilibrium/coronal heating are among the topics covered.

  4. Geometry of solar coronal rays

    NASA Astrophysics Data System (ADS)

    Filippov, B. P.; Martsenyuk, O. V.; Platov, Yu. V.; Den, O. E.

    2016-02-01

    Coronal helmet streamers are the most prominent large-scale elements of the solar corona observed in white light during total solar eclipses. The base of the streamer is an arcade of loops located above a global polarity inversion line. At an altitude of 1-2 solar radii above the limb, the apices of the arches sharpen, forming cusp structures, above which narrow coronal rays are observed. Lyot coronagraphs, especially those on-board spacecrafts flying beyond the Earth's atmosphere, enable us to observe the corona continuously and at large distances. At distances of several solar radii, the streamers take the form of fairly narrow spokes that diverge radially from the Sun. This radial direction displays a continuous expansion of the corona into the surrounding space, and the formation of the solar wind. However, the solar magnetic field and solar rotation complicate the situation. The rotation curves radial streams into spiral ones, similar to water streams flowing from rotating tubes. The influence of the magnetic field is more complex and multifarious. A thorough study of coronal ray geometries shows that rays are frequently not radial and not straight. Coronal streamers frequently display a curvature whose direction in the meridional plane depends on the phase of the solar cycle. It is evident that this curvature is related to the geometry of the global solar magnetic field, which depends on the cycle phase. Equatorward deviations of coronal streamers at solar minima and poleward deviations at solar maxima can be interpreted as the effects of changes in the general topology of the global solar magnetic field. There are sporadic temporal changes in the coronal rays shape caused by remote coronal mass ejections (CMEs) propagating through the corona. This is also a manifestation of the influence of the magnetic field on plasma flows. The motion of a large-scale flux rope associated with a CME away from the Sun creates changes in the structure of surrounding field

  5. Wavefront reconstruction from tangential and sagittal curvature.

    PubMed

    Canales, Javier; Barbero, Sergio; Portilla, Javier; López-Alonso, José Manuel

    2014-12-10

    In a previous contribution [Appl. Opt.51, 8599 (2012)], a coauthor of this work presented a method for reconstructing the wavefront aberration from tangential refractive power data measured using dynamic skiascopy. Here we propose a new regularized least squares method where the wavefront is reconstructed not only using tangential but also sagittal curvature data. We prove that our new method provides improved quality reconstruction for typical and also for highly aberrated wavefronts, under a wide range of experimental error levels. Our method may be applied to any type of wavefront sensor (not only dynamic skiascopy) able to measure either just tangential or tangential plus sagittal curvature data. PMID:25608069

  6. Walking in simulated Martian gravity: Influence of added weight on sagittal dynamic stability

    NASA Astrophysics Data System (ADS)

    Scott-Pandorf, Melissa M.; O'Connor, Daniel P.; Layne, Charles S.; Josić, Krešimir; Kurz, Max J.

    2010-05-01

    With human exploration of the Moon and Mars on the horizon, research considerations for space suit redesign have surfaced. Review of Apollo mission videos revealed repeated instance of falling during extravehicular activities. A better understanding of how suit weight influences the sagittal dynamic stability of the gait pattern may provide insight for new suit design such that space missions may have more productive extravehicular activities and smaller risk of falls that may cause injuries and damage equipment. Participants walked for 4 min in simulated Martian gravity with additional loads of 0%, 15%, 30% and 45% of their body weight. Floquet and Lyapunov analysis techniques were used to quantify the dynamic stability of the sagittal plane gait pattern. Additionally, sagittal plane joint kinematics were evaluated to determine if any modification occurred. Results indicated that weight (i.e., added load) had little effect on the sagittal dynamic stability or joint kinematics while in simulated Martian gravity. Potentially, suit weight may not be a priority for space suit redesign.

  7. Sagittal evaluation of elemental geometrical dimensions of human vertebrae.

    PubMed Central

    Gilad, I; Nissan, M

    1985-01-01

    Geometrical configuration and dimensions of the human vertebra were investigated using radiographs of 157 normal healthy adult men. Measurements were based on five bony reference points, which can be defined in radiographs. The measurements permit the determination of nine dimensions that can be used for anthropometrical evaluation of the cervical and lumbar vertebrae. A simplified model of the vertebra in the sagittal plane is presented and serves as a basis for the geometrical measurements. In the cervical region, average width exceeded average height of vertebral bodies C3 to C7, while in C2 the average width was smaller than the average height; C7 was the longest and C3 the shortest cervical vertebra. In the lumbar region, average width exceeded average height of the vertebral bodies. Values for width and height did not differ significantly from L1 to L5; L3 was the longest and L5 the shortest lumbar vertebra. Images Fig. 1 PMID:3870717

  8. The Relationship between T1 Sagittal Angle and Sagittal Balance: A Retrospective Study of 119 Healthy Volunteers

    PubMed Central

    Li, Ming

    2016-01-01

    T1 sagittal angle has been reported to be used as a parameter for assessing sagittal balance and cervical lordosis. However, no study has been performed to explore the relationship between T1 sagittal angle and sagittal balance, and whether T1 sagittal angle could be used for osteotomy guidelines remains unknown. The aim of our study is to explore the relationship between T1 sagittal angle and sagittal balance, determine the predictors for T1 sagittal angle, and determine whether T1 sagittal angle could be used for osteotomy guidelines to restore sagittal balance. Medical records of healthy volunteers in our outpatient clinic from January 2014 to August 2015 were reviewed, and their standing full-spine lateral radiographs were evaluated. Demographic and radiological parameters were collected and analyzed, including age, gender, T1 sagittal angle, maxTK, maxLL, SS, PT, and PI. Correlation coefficients between T1 sagittal angle and other spinopelvic parameters were determined. In addition, multiple regression analysis was performed to establish predictive radiographic parameters for T1 sagittal angle as the primary contributors. A total of 119 healthy volunteers were recruited in our study with a mean age of 34.7 years. It was found that T1 sagittal angle was correlated with maxTK with very good significance (r = 0.697, P<0.001), maxLL with weak significance (r = 0.206, P = 0.024), SS with weak significance (r = 0.237, P = 0.009), PI with very weak significance (r = 0.189, P = 0.039), SVA with moderate significance (r = 0.445, P<0.001), TPA with weak significance (r = 0.207, P = 0.023), and T1SPI with weak significance (r = 0.309, P = 0.001). The result of multiple regression analysis showed that T1 sagittal angle could be predicted by using the following regression equation: T1 sagittal angle = 0.6 * maxTK—0.2 * maxLL + 8. In the healthy population, T1 sagittal angle could be considered as a useful parameter for sagittal balance; however, it could not be

  9. Coronal Fractures of the Scaphoid: A Review.

    PubMed

    Slutsky, David J; Herzberg, Guillaume; Shin, Alexander Y; Buijze, Geert A; Ring, David C; Mudgal, Chaitanya S; Leung, Yuen-Fai; Dumontier, Christian

    2016-08-01

    Coronal (or frontal plane) fractures of the scaphoid are distinctly uncommon. There are few published reports of coronal fractures of the scaphoid. This fracture is often missed on the initial X-ray films. A high index of suspicion should exist when there is a double contour of the proximal scaphoid pole on the anteroposterior X-ray view. A computed tomography scan is integral in making the diagnosis. Early recognition is key in salvaging the scaphoid fracture and in preventing articular damage. Level of Evidence IV. Retrospective case series. PMID:27574573

  10. A three-plane architectonic atlas of the rat hippocampal region.

    PubMed

    Boccara, Charlotte N; Kjonigsen, Lisa J; Hammer, Ingvild M; Bjaalie, Jan G; Leergaard, Trygve B; Witter, Menno P

    2015-07-01

    The hippocampal region, comprising the hippocampal formation and the parahippocampal region, has been one of the most intensively studied parts of the brain for decades. Better understanding of its functional diversity and complexity has led to an increased demand for specificity in experimental procedures and manipulations. In view of the complex 3D structure of the hippocampal region, precisely positioned experimental approaches require a fine-grained architectural description that is available and readable to experimentalists lacking detailed anatomical experience. In this paper, we provide the first cyto- and chemoarchitectural description of the hippocampal formation and parahippocampal region in the rat at high resolution and in the three standard sectional planes: coronal, horizontal and sagittal. The atlas uses a series of adjacent sections stained for neurons and for a number of chemical marker substances, particularly parvalbumin and calbindin. All the borders defined in one plane have been cross-checked against their counterparts in the other two planes. The entire dataset will be made available as a web-based interactive application through the Rodent Brain WorkBench (http://www.rbwb.org) which, together with this paper, provides a unique atlas resource. PMID:25533645

  11. Effect of growing rod on sagittal and spinopelvic parameters in early-onset scoliosis patients.

    PubMed

    Sariyilmaz, Kerim; Akgul, Turgut; Ozkunt, Okan; Dikici, Fatih; Korkmaz, Murat; Sar, Cuneyt; Domanic, Unsal

    2016-05-01

    Growing rod is a commonly used surgery for early-onset scoliosis (EOS). However, the effect of growing-rod lengthening on the spinopelvic alignment is unclear. In this study, 21 EOS patients treated by growing rod were evaluated retrospectively and thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI) , sacral slope (SS), pelvic tilt (PT), and sagittal vertical axis (SVA) were measured. Preoperatively, the mean TK, LL, PI, PT, SS, and SVA were 27.4°, 35.2°, 43.8°, 7.5°, 33.8°, and 47.7 mm respectively. After the last lengthening, TK, LL, PI, PT, SS, and SVA were 28.3°, 28.06°, 41.4°, 7°, 5.2°, and 42.6 mm, respectively. The sagittal plane parameters in our EOS patients were not significantly altered during the lengthening period. PMID:27007546

  12. Can coronal hole spicules reach coronal temperatures?

    NASA Astrophysics Data System (ADS)

    Madjarska, M. S.; Vanninathan, K.; Doyle, J. G.

    2011-08-01

    Aims: The present study aims to provide observational evidence of whether coronal hole spicules reach coronal temperatures. Methods: We combine multi-instrument co-observations obtained with the SUMER/SoHO and with the EIS/SOT/XRT/Hinode. Results: The analysed three large spicules were found to be comprised of numerous thin spicules that rise, rotate, and descend simultaneously forming a bush-like feature. Their rotation resembles the untwisting of a large flux rope. They show velocities ranging from 50 to 250 kms-1. We clearly associated the red- and blue-shifted emissions in transition region lines not only with rotating but also with rising and descending plasmas. Our main result is that these spicules although very large and dynamic, are not present in the spectral lines formed at temperatures above 300 000 K. Conclusions: In this paper we present the analysis of three Ca ii H large spicules that are composed of numerous dynamic thin spicules but appear as macrospicules in lower resolution EUV images. We found no coronal counterpart of these and smaller spicules. We believe that the identification of phenomena that have very different origins as macrospicules is due to the interpretation of the transition region emission, and especially the He ii emission, wherein both chromospheric large spicules and coronal X-ray jets are present. We suggest that the recent observation of spicules in the coronal AIA/SDO 171 Å and 211 Å channels probably comes from the existence of transition region emission there. Movie is available in electronic form at http://www.aanda.org

  13. Internal derangements of the temporomandibular joint: diagnosis by direct sagittal computed tomography

    SciTech Connect

    Manzione, J.V.; Katzberg, R.W.; Brodsky, G.L.; Seltzer, S.E.; Mellins, H.Z.

    1984-01-01

    The authors performed direct sagittal computed tomography (CT) on 4 cadaver temporomandibular joints (TMJ) and examined 51 TMJs in 47 patients clinically. The results were correlated with cadaver anatomical sections and clinical arthrographic findings. A fat plane between the bellies of the lateral pterygoid muscles, termed the ''lateral pterygoid fat pad,'' served as the anatomical basis for detection of internal derangements by CT. CT was 94% accurate in detecting meniscal derangements and 96% accurate in detecting degenerative arthritis. The authors suggest that CT rather than arthrography be employed as the primary TMJ imaging modality when internal derangement or arthritis is suspected.

  14. SPINNING MOTIONS IN CORONAL CAVITIES

    SciTech Connect

    Wang, Y.-M.; Stenborg, G. E-mail: guillermo.stenborg.ctr.ar@nrl.navy.mi

    2010-08-20

    In movies made from Fe XII 19.5 nm images, coronal cavities that graze or are detached from the solar limb appear as continually spinning structures, with sky-plane projected flow speeds in the range 5-10 km s{sup -1}. These whirling motions often persist in the same sense for up to several days and provide strong evidence that the cavities and the immediately surrounding streamer material have the form of helical flux ropes viewed along their axes. A pronounced bias toward spin in the equatorward direction is observed during 2008. We attribute this bias to the poleward concentration of the photospheric magnetic flux near sunspot minimum, which leads to asymmetric heating along large-scale coronal loops and tends to drive a flow from higher to lower latitudes; this flow is converted into an equatorward spinning motion when the loops pinch off to form a flux rope. As sunspot activity increases and the polar fields weaken, we expect the preferred direction of the spin to reverse.

  15. Gender differences in sagittal standing alignment before pubertal peak growth: the importance of subclassification and implications for spinopelvic loading

    PubMed Central

    Dolphens, Mieke; Cagnie, Barbara; Vleeming, Andry; Vanderstraeten, Guy; Danneels, Lieven

    2013-01-01

    The aim of this study was to analyze gender differences in sagittal standing alignment at pre-peak height velocity age thereby applying a scientifically sound and practically oriented classification scheme for overall standing balance. The study population consisted of healthy boys (n = 639) and girls (n = 557) before pubertal peak growth. During subjects' habitual standing, sagittal plane measures of the spine, pelvis and lower limbs were collected using a clinical screening protocol. With each subject classified as one of three postural types (neutral, sway-back, or leaning-forward), differences in sagittal plane alignment were analyzed between sexes. The results revealed clear differences between genders in each of the postural types. Within the neutral and sway-back postural subgroups, boys presented more forward inclination of the trunk, more thoracic kyphosis and more pelvis backtilt compared with girls. Within the leaning-forward category, girls displayed more forward trunk lean, less thoracic kyphosis and more pelvic anteversion. A state of lumbar segmental hyperextension appeared to exist in female leaning-forward subjects. Our results reveal for the first time that sagittal standing alignment is different between prepubescent boys and girls when subjects are appropriately subclassified, and conversely represent a ‘wash-out effect’ when pooled. When the classification system is applied, gender-specificity in gravity line position is suggested, implying gender-related differences in lever arms and thus load. Present findings may add to our understanding of gender-specific biomechanical challenges posed by habitual posture, and may shed new light on sagittal standing alignment as a possible contributory factor in developmental spinal-pelvic disorders. PMID:24107185

  16. Coronal holes, solar wind streams, and recurrent geomagnetic disturbances - 1973-1976

    NASA Technical Reports Server (NTRS)

    Sheeley, N. R., Jr.; Harvey, J. W.; Feldman, W. C.

    1976-01-01

    Observations of coronal holes, solar-wind streams, and geomagnetic disturbances during 1973-1976 are compared in a 27-day pictorial format which shows their long-term evolution. The results leave little doubt that coronal holes are related to the high-speed streams and their associated recurrent geomagnetic disturbances. In particular, these observations strongly support the hypothesis that coronal holes are the solar origin of the high-speed streams observed in the solar wind near the ecliptic plane.

  17. Sagittal otolith morphogenesis asymmetry in marine fishes.

    PubMed

    Mille, T; Mahe, K; Villanueva, M C; De Pontual, H; Ernande, B

    2015-09-01

    This study investigated and compared asymmetry in sagittal otolith shape and length between left and right inner ears in four roundfish and four flatfish species of commercial interest. For each species, the effects of ontogenetic changes (individual age and total body length), sexual dimorphism (individual sex) and the otolith's location on the right or left side of the head, on the shape and length of paired otoliths (between 143 and 702 pairs according to species) were evaluated. Ontogenetic changes in otolith shape and length were observed for all species. Sexual dimorphism, either in otolith shape and length or in their ontogenetic changes, was detected for half of the species, be they round or flat. Significant directional asymmetry in otolith shape and length was detected in one roundfish species each, but its inconsistency across species and its small average amplitude (6·17% for shape and 1·99% for length) suggested that it has barely any biological relevance. Significant directional asymmetry in otolith shape and length was found for all flatfish species except otolith length for one species. Its average amplitude varied between 2·06 and 17·50% for shape and between 0·00 and 11·83% for length and increased significantly throughout ontogeny for two species, one dextral and one sinistral. The longer (length) and rounder otolith (shape) appeared to be always on the blind side whatever the species. These results suggest differential biomineralization between the blind and ocular inner ears in flatfish species that could result from perturbations of the proximal-distal gradient of otolith precursors in the endolymph and the otolith position relative to the geometry of the saccular epithelium due to body morphology asymmetry and lateralized behaviour. The fact that asymmetry never exceeded 18% even at the individual level suggests an evolutionary canalization of otolith shape symmetry to avoid negative effects on fish hearing and balance. Technically

  18. Temporomandibular joint: true sagittal computed tomography with meniscus visualization

    SciTech Connect

    Sartorix, D.J.; Neumann, C.H.; Riley, R.W.

    1984-01-01

    Accessory patient support equipment was constructed that allows patient positioning for true sagittal projection of the temporomandibular joint using a GE 8800 CT/T scanner. Range of motion abnormalities, osseous alterations of the mandibular condyle and temporal bone, joint-space narrowing, and meniscal configuration may be demonstrated. The technique has potential advantages over other CT projections and sagittal reconstruction for evaluation of temporomandibular joint dysfunction.

  19. Episodic coronal heating

    NASA Technical Reports Server (NTRS)

    Sturrock, P. A.; Dixon, W. W.; Klimchuk, J. A.; Antiochos, S. K.

    1990-01-01

    A study is made of the observational consequences of the hypothesis that there is no steady coronal heating, the solar corona instead being heated episodically, such that each short burst of heating is followed by a long period of radiative cooling. The form of the resulting contribution to the differential emission measure (DEM), and to a convenient related function (the differential energy flux, DEF) is calculated. Observational data for the quiet solar atmosphere indicate that the upper branch of the DEM, corresponding to temperatures above 100,000 K, can be interpreted in terms of episodic energy injection at coronal temperatures.

  20. Episodic coronal heating

    NASA Astrophysics Data System (ADS)

    Sturrock, P. A.; Dixon, W. W.; Klimchuk, J. A.; Antiochos, S. K.

    1990-06-01

    A study is made of the observational consequences of the hypothesis that there is no steady coronal heating, the solar corona instead being heated episodically, such that each short burst of heating is followed by a long period of radiative cooling. The form of the resulting contribution to the differential emission measure (DEM), and to a convenient related function (the differential energy flux, DEF) is calculated. Observational data for the quiet solar atmosphere indicate that the upper branch of the DEM, corresponding to temperatures above 100,000 K, can be interpreted in terms of episodic energy injection at coronal temperatures.

  1. Geometrical Properties of Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Cremades, Hebe; Bothmer, Volker

    Based on the SOHO/LASCO dataset, a collection of "structured" coronal mass ejections (CMEs) has been compiled within the period 1996-2002, in order to analyze their three-dimensional configuration. These CME events exhibit white-light fine structures, likely indicative of their possible 3D topology. From a detailed investigation of the associated low coronal and photospheric source regions, a generic scheme has been deduced, which considers the white-light topology of a CME projected in the plane of the sky as being primarily dependent on the orientation and position of the source region's neutral line on the solar disk. The obtained results imply that structured CMEs are essentially organized along a symmetry axis, in a cylindrical manner. The measured dimensions of the cylinder's base and length yield a ratio of 1.6. These CMEs seem to be better approximated by elliptic cones, rather than by the classical ice cream cone, characterized by a circular cross section.

  2. Analysis of Global Sagittal Postural Patterns in Asymptomatic Chinese Adults

    PubMed Central

    Hu, Panpan; Yu, Miao; Sun, Zhuoran; Li, Weishi; Jiang, Liang; Wei, Feng; Chen, Zhongqiang; Liu, Zhongjun

    2016-01-01

    Study Design A prospective imaging study. Purpose To characterize the distribution of the global sagittal postural patterns in asymptomatic Chinese adults using Roussouly classification. Overview of Literature The norms of sagittal parameters in asymptomatic Chinese population have been previously described, but no report described their global sagittal postural patterns as characterized by Roussouly classification. Methods A cohort of 272 asymptomatic Chinese adults was recruited. Data was assimilated by reviewing the films for each subject. Sagittal parameters were measured and sagittal postural patterns were then determined according to Roussouly classification. The pattern distributions were compared across genders within the study cohort. We also compared the data across different ethnicities from our study and a previous study to further characterize Chinese sagittal postures. Results The cohort included 161 males and 111 females, with mean age of 23.2±4.4 years. The average descriptive results were as below: pelvic incidence (PI) 46.4°±9.6°, thoracic kyphosis (TK) 24.2°±9.0°, lumbar lordosis (LL) 50.6°±10.6°, sacral slope (SS) 37.2°±7.6°, pelvic tilt (PT) 9.4°±6.8°, spinosacral angle (SSA) 131.1°±7.5° and sagittal vertical axis (SVA) 17.24±32.36 mm. Despite a significant difference between two genders in LL, PI, SSA, and SVA, no difference was found in the distribution of Roussouly types among them. 47.8% of our cohort belonged to Roussouly type 3, while type 1, 2 and 4 comprised 23.2%, 14.0% and 15.1% of the subjects, respectively. Roussouly classification was capable of categorizing sagittal parameters except for the PT. This study also found that 4.4% of the recruited subjects belonged to the C7-anterior subgroup. Conclusions From a characterization of the sagittal postural patterns of asymptomatic Chinese adults using Roussouly classification, the distribution was similar between Chinese males and females; however, from a cross

  3. How is sagittal balance acquired during bipedal gait acquisition? Comparison of neonatal and adult pelves in three dimensions. Evolutionary implications.

    PubMed

    Tardieu, Christine; Bonneau, Noémie; Hecquet, Jérôme; Boulay, Christophe; Marty, Catherine; Legaye, Jean; Duval-Beaupère, Geneviève

    2013-08-01

    We compare adult and intact neonatal pelves, using a pelvic sagittal variable, the angle of sacral incidence, which presents significant correlations with vertebral curvature in adults and plays an important role in sagittal balance of the trunk on the lower limbs. Since the lumbar curvature develops in the child in association with gait acquisition, we expect a change in this angle during growth which could contribute to the acquisition of sagittal balance. To understand the mechanisms underlying the sagittal balance in the evolution of human bipedalism, we also measure the angle of incidence of hominid fossils. Fourty-seven landmarks were digitized on 50 adult and 19 intact neonatal pelves. We used a three-dimensional model of the pelvis (DE-VISU program) which calculates the angle of sacral incidence and related functional variables. Cross-sectional data from newborns and adults show that the angle of sacral incidence increases and becomes negatively correlated with the sacro-acetabular distance. During ontogeny the sacrum becomes curved, tends to sink down between the iliac blades as a wedge and moves backward in the sagittal plane relative to the acetabula, thus contributing to the backwards displacement of the center of gravity of the trunk. A chain of correlations links the degree of the sacral slope and of the angle of incidence, which is tightly linked with the lumbar lordosis. We sketch a model showing the coordinated changes occurring in the pelvis and vertebral column during the acquisition of bipedalism in infancy. In the australopithecine pelves, Sts 14 and AL 288-1, and in the Homo erectus Gona pelvis the angle of sacral incidence reaches the mean values of humans. Discussing the incomplete pelves of Ardipithecus ramidus, Australopithecus sediba and the Nariokotome Boy, we suggest how the functional linkage between pelvis and spine, observed in humans, could have emerged during hominid evolution. PMID:23838060

  4. Global Coronal Waves

    NASA Astrophysics Data System (ADS)

    Chen, P. F.

    2016-02-01

    After the Solar and Heliospheric Observatory (SOHO) was launched in 1996, the aboard Extreme Ultraviolet Imaging Telescope (EIT) observed a global coronal wave phenomenon, which was initially named ``EIT wave" after the telescope. The bright fronts are immediately followed by expanding dimmings. It has been shown that the brightenings and dimmings are mainly due to plasma density increase and depletion, respectively. Such a spectacular phenomenon sparked long-lasting interest and debates. The debates were concentrated on two topics, one is about the driving source, and the other is about the nature of this wavelike phenomenon. The controversies are most probably because there may exist two types of large-scale coronal waves that were not well resolved before the Solar Dynamics Observatory (SDO) was launched: one is a piston-driven shock wave straddling over the erupting coronal mass ejection (CME), and the other is an apparently propagating front, which may correspond to the CME frontal loop. Such a two-wave paradigm was proposed more than 13 years ago, and now is being recognized by more and more colleagues. In this paper, we review how various controversies can be resolved in the two-wave framework and how important it is to have two different names for the two types of coronal waves.

  5. Solar wind and coronal structure

    NASA Technical Reports Server (NTRS)

    Withbroe, G. L.

    1983-01-01

    Spectroscopic diagnostic techniques used to determine the coronal source region of the solar wind, and results of preliminary applications are examined. The topics reviewed are magnetic fields, coronal mass ejections, coronal holes, flow velocities, coronal temperatures, fine spatial structure, and future observational programs. The physical mechanisms responsible for plasma heating, solar-wind acceleration, the transport of mass momentum and energy, and the spatial differentiation of chemical abundances are also discussed. Among the data presented are Skylab's white-light coronagraph photograph of a coronal transient, X-ray photographs of the corona, and spectroheliograms showing bright points overlying polar plumes, and macrospicules.

  6. Coronal mass ejections and coronal structures

    NASA Technical Reports Server (NTRS)

    Hildner, E.; Bassi, J.; Bougeret, J. L.; Duncan, R. A.; Gary, D. E.; Gergely, T. E.; Harrison, R. A.; Howard, R. A.; Illing, R. M. E.; Jackson, B. V.

    1986-01-01

    Research on coronal mass ejections (CMF) took a variety of forms, both observational and theoretical. On the observational side there were: case studies of individual events, in which it was attempted to provide the most complete descriptions possible, using correlative observations in diverse wavelengths; statistical studies of the properties CMEs and their associated activity; observations which may tell us about the initiation of mass ejections; interplanetary observations of associated shocks and energetic particles even observations of CMEs traversing interplanetary space; and the beautiful synoptic charts which show to what degree mass ejections affect the background corona and how rapidly (if at all) the corona recovers its pre-disturbance form. These efforts are described in capsule form with an emphasis on presenting pictures, graphs, and tables so that the reader can form a personal appreciation of the work and its results.

  7. Diffraction crystal for sagittally focusing x-rays

    DOEpatents

    Ice, Gene E.; Sparks, Jr., Cullie J.

    1984-01-01

    The invention is a new type of diffraction crystal designed for sagittally focusing photons of various energies. The invention is based on the discovery that such focusing is not obtainable with conventional crystals because of distortion resulting from anticlastic curvature. The new crystal comprises a monocrystalline base having a front face contoured for sagittally focusing photons and a back face provided with rigid, upstanding, stiffening ribs restricting anticlastic curvature. When mounted in a suitable bending device, the reflecting face of the crystal can be adjusted to focus photons having any one of a range of energies.

  8. Diffraction crystals for sagittally focusing x-rays

    DOEpatents

    Ice, G.E.; Sparks, C.J. Jr.

    1982-06-07

    The invention is a new type of diffraction crystal designed for sagittally focusing photons of various energies. The invention is based on the discovery that such focusing is not obtainable with conventional crystals because of distortion resulting from anticlastic curvature. The new crystal comprises a monocrystalline base having a front face contoured for sagittally focusing photons and a back face provided with rigid, upstanding, stiffening ribs restricting anticlastic curvature. When mounted in a suitable bending device, the reflecting face of the crystal can be adjusted to focus photons having any one of a range of energies.

  9. Sagittal mandibular osteotomy for removal of intraosseous lesion.

    PubMed

    de Oliveira, Júlio César Silva; Garcia, Idelmo Rangel; de Melo, Willian Morais; de Matos Barbosa, Saulo; Rabêlo, Paulo Maria Santos; Bastos, Eider Guimarães

    2014-05-01

    The ramus sagittal split osteotomy or mandibular body is an established technique for correction of dentofacial deformities but can have an accurate indication in cases requiring surgical access to remove lesions or more teeth included in the region of the mandibular angle. The main advantages of this technique are the possibility of preservation of the inferior alveolar nerve bundle and significant reduction in postoperative morbidity. In this article, the authors show a case in which the sagittal osteotomy of the mandible was used to gain access for removal of a lesion (complex odontoma). PMID:24820725

  10. Coronal mass ejections

    SciTech Connect

    Steinolfson, R.S.

    1990-01-01

    Coronal mass ejections (CMEs) are now recognized as an important component of the large-scale evolution of the solar corona. Some representative observations of CMEs are reviewed with emphasis on more recent results. Recent observations and theory are examined as they relate to the following aspects of CMEs: (1) the role of waves in determining the white-light signature; and (2) the mechanism by which the CME is driven (or launched) into the corona.

  11. Chromospheres of Coronal Stars

    NASA Technical Reports Server (NTRS)

    Linsky, Jeffrey L.; Wood, Brian E.

    1996-01-01

    We summarize the main results obtained from the analysis of ultraviolet emission line profiles of coronal late-type stars observed with the Goddard High Resolution Spectrograph (GHRS) on the Hubble Space Telescope. The excellent GHRS spectra provide new information on magnetohydrodynamic phenomena in the chromospheres and transition regions of these stars. One exciting new result is the discovery of broad components in the transition region lines of active stars that we believe provide evidence for microflare heating in these stars.

  12. Radio Coronal Magnetography of a Large Active Region

    NASA Astrophysics Data System (ADS)

    Bastian, Timothy S.; Gary, Dale E.; White, Stephen; Fleishman, Gregory; Chen, Bin

    2015-04-01

    Quantitative knowledge of coronal magnetic fields is fundamental to understanding energetic phenomena such as solar flares. Flares occur in solar active regions where strong, non-potential magnetic fields provide free energy. While constraints on the coronal magnetic field topology are readily available through high resolution SXR and EUV imaging of solar active regions, useful quantitative measurements of coronal magnetic fields have thus far been elusive. Recent progress has been made at infrared (IR) wavelengths in exploiting both the Zeeman and Hanle effects to infer the line-of-sight magnetic field strength or the orientation of the magnetic field vector in the plane of the sky above the solar limb. However, no measurements of coronal magnetic fields against the solar disk are possible using IR observations. Radio observations of gyroresonance emission from active regions offer the means of measuring coronal magnetic fields above the limb and on the solar disk. In particular, for plasma plasma conditions in the solar corona, active regions typically become optically thick to emission over a range of radio frequencies through gyroresonance absorption at a low harmonic of the electron gyrofrequency. The specific range of resonant frequencies depends on the range of coronal magnetic field strengths present in the active region.The Karl G. Jansky Very Large Array was used in November 2014 to image NOAA/USAF active region AR12209 over a continuous frequency range of 1-8 GHz, corresponding to a wavelength range of 3.75-30 cm. This frequency range is sensitive to coronal magnetic field strengths ranging from ~120-1400G. The active region was observed on four different dates - November 18, 20, 22, and 24 - during which the active region longitude ranged from -15 to +70 degrees, providing a wide range of aspect angles. In this paper we provide a preliminary description of the coronal magnetic field measurements derived from the radio observations.

  13. Influence of metopic suture fusion associated with sagittal synostosis.

    PubMed

    Domeshek, Leahthan F; Das, Rajesh R; Van Aalst, John A; Mukundan, Srinivasan; Marcus, Jeffrey R

    2011-01-01

    Some patients with sagittal synostosis present with a fused metopic suture. We hypothesize that premature metopic suture fusion consistently and identifiably alters form associated with sagittal synostosis. We previously validated three-dimensional vector analysis as a tool for the study of cranial morphology and used it herein to distinguish between dysmorphologies of isolated sagittal synostosis (ISS) and combined sagittal-metopic synostosis (CSM). Preoperative computed tomographic scans for patients with ISS and CSM were compared with matched normative counterparts. Premature metopic suture fusion was defined by established radiographic criteria. Color-coded point clouds were created for each scan, with color gradient based on patient deviation from normal across the dysmorphic skull. Standard deviation data were evaluated in 7 cranial regions and compared between ISS and CSM. Mean ISS and CSM point clouds were evaluated. Using three-dimensional vector analysis, standard anthropometric data/indices were determined and compared between the 2 groups. Differences in ISS and CSM regional deviations and index measurements were not statistically significant. Mean ISS and CSM representations depicted similar overall morphology. Using accepted criteria for identification of metopic synostosis in CSM, only subtle differences appear between the 2 populations on average. Expected morphologic changes associated with metopic synostosis are present in only a small number of patients with CSM, arguing against our hypothesis, and calling into question the criteria used to identify premature metopic suture fusion. Normal metopic suture fusion occurs for a continuum of time. Our findings suggest that the normal continuum may begin earlier than the literature suggests. In the setting of sagittal synostosis, the influence of metopic suture fusion and treatment is best determined by individual morphologic analysis. PMID:21187774

  14. Sagittal plane ground reaction forces, centre of pressure and centre of mass in trotting horses.

    PubMed

    Hobbs, Sarah J; Clayton, Hilary M

    2013-12-01

    The aims of this study were to measure ground reaction forces (GRFs) of concurrently loaded limbs and to evaluate spatial relationships between the centre of pressure (COP) and centre of mass (COM) in trotting horses. Kinematic (120Hz) and GRF data were collected at trot from three trials of eight horses using four force plates (960 Hz). Forelimb and hind limb GRFs were measured, COP was calculated from the resultant vertical GRF vector and COM was calculated by summation of weighted segmental COMs. Peak total vertical force (19.3 ± 1.3N/kg at 45.1 ± 2.3% diagonal stance) coincided with zero total longitudinal force (45.1 ± 2.4% stance). Initially, COP position corresponded with the fore or hind hoof of the diagonal that contacted the ground earlier. During diagonal overlap, COP position reflected forelimb contribution to total vertical GRF; it maintained a fairly constant position relative to the base of support through the middle part of stance, then moved cranially in the last third of stance towards the fore hoof, which was always the last hoof to leave the ground. The COM moved forward continuously; its longitudinal velocity decreased with the net braking force in early stance and increased with the net propulsive force in late stance. The COM was caudal to the COP in early stance, coincident at 35.8 ± 4.4% stance and was maximally ahead of the COP at 67.6 ± 4.8% stance. Changes in the spatial relationship between COP and COM affect the moment arms of the forelimb and hind limb vertical GRFs and their effect in generating a pitching torque around the COM. PMID:24138935

  15. Markerless motion capture can provide reliable 3D gait kinematics in the sagittal and frontal plane.

    PubMed

    Sandau, Martin; Koblauch, Henrik; Moeslund, Thomas B; Aanæs, Henrik; Alkjær, Tine; Simonsen, Erik B

    2014-09-01

    Estimating 3D joint rotations in the lower extremities accurately and reliably remains unresolved in markerless motion capture, despite extensive studies in the past decades. The main problems have been ascribed to the limited accuracy of the 3D reconstructions. Accordingly, the purpose of the present study was to develop a new approach based on highly detailed 3D reconstructions in combination with a translational and rotational unconstrained articulated model. The highly detailed 3D reconstructions were synthesized from an eight camera setup using a stereo vision approach. The subject specific articulated model was generated with three rotational and three translational degrees of freedom for each limb segment and without any constraints to the range of motion. This approach was tested on 3D gait analysis and compared to a marker based method. The experiment included ten healthy subjects in whom hip, knee and ankle joint were analysed. Flexion/extension angles as well as hip abduction/adduction closely resembled those obtained from the marker based system. However, the internal/external rotations, knee abduction/adduction and ankle inversion/eversion were less reliable. PMID:25085672

  16. CORONAL RAIN AS A MARKER FOR CORONAL HEATING MECHANISMS

    SciTech Connect

    Antolin, P.; Vissers, G.; Shibata, K. E-mail: g.j.m.vissers@astro.uio.n

    2010-06-10

    Reported observations in H{alpha}, Ca II H, and K or other chromospheric lines of coronal rain trace back to the days of the Skylab mission. Corresponding to cool and dense plasma, coronal rain is often observed falling down along coronal loops in active regions. A physical explanation for this spectacular phenomenon has been put forward thanks to numerical simulations of loops with footpoint-concentrated heating, a heating scenario in which cool condensations naturally form in the corona. This effect has been termed 'catastrophic cooling' and is the predominant explanation for coronal rain. In this work, we further investigate the link between this phenomenon and the heating mechanisms acting in the corona. We start by analyzing observations of coronal rain at the limb in the Ca II H line performed by the Hinode satellite, and derive interesting statistical properties concerning the dynamics. We then compare the observations with 1.5-dimensional MHD simulations of loops being heated by small-scale discrete events concentrated toward the footpoints (that could come, for instance, from magnetic reconnection events), and by Alfven waves generated at the photospheric level. Both our observation and simulation results suggest that coronal rain is a far more common phenomenon than previously thought. Also, we show that the structure and dynamics of condensations are far more sensitive to the internal pressure changes in loops than to gravity. Furthermore, it is found that if a loop is predominantly heated from Alfven waves, coronal rain is inhibited due to the characteristic uniform heating they produce. Hence, coronal rain may not only point to the spatial distribution of the heating in coronal loops but also to the agent of the heating itself. We thus propose coronal rain as a marker for coronal heating mechanisms.

  17. Modeling Coronal Jets with FLUX

    NASA Astrophysics Data System (ADS)

    Rachmeler, L. A.; Pariat, E.; Antiochos, S. K.; Deforest, C. E.

    2008-05-01

    We report on a comparative study of coronal jet formation with and without reconnection using two different simulation strategies. Coronal jets are features on the solar surface that appear to have some properties in common with coronal mass ejections, but are less energetic, massive, and broad. Magnetic free energy is built up over time and then suddenly released, which accelerates plasma outward in the form of a coronal jet. We compare results from the ARMS adaptive mesh and FLUX reconnection-less codes to study the role of reconnection in this system. This is the first direct comparison between FLUX and a numerical model with a 3D spatial grid.

  18. Shock Formation of Slow Magnetosonic Waves in Coronal Plumes

    NASA Technical Reports Server (NTRS)

    Cuntz, Manfred; Suess, Steve; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    We investigate the height of shock formation in coronal plumes for slow magnetosonic waves. The models take into account plume geometric spreading, heat conduction, and radiative damping. The wave parameters as well as the spreading functions of the plumes and the base magnetic field strengths are given by empirical constraints mostly from Solar and Heliospheric Observatory (SOHO)/ Ultraviolet Coronograph Spectrometer (UVCS), Extreme Ultraviolet Imaging Telescope (EIT), Michelson Doppler Imager (MDI), and Large Angle Spectrometric Coronagraph (LASCO). Our models show that shock formation occurs at relatively low coronal heights, typically within 1.2 RsuN, depending on the model parameters. The shock formation is calculated using the well-established wave breaking criterion given by the intersection of C+ characteristics in the space-time plane. Our models show that shock heating by slow magnetosonic waves is expected to be relevant at most heights in solar coronal plumes, although such waves are probably not the main energy supply mechanism.

  19. Shock Formation of Slow Magnetosonic Waves in Coronal Plumes

    NASA Technical Reports Server (NTRS)

    Cuntz, Manfred; Suess, Steven T.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    We investigate the height of shock formation in coroner plumes for slow magnetosonic waves. The models take into account plume geometric spreading, heat conduction and radiative damping. The wave parameters as well as the spreading functions of the plumes and the base magnetic field strengths are given by empirical constraints mostly from Solar and Heliospheric Observatory/Ultraviolet Coronagraph Spectrometer (SOHO/UVCS). Our models show that shock formation occurs at low coronal heights, i.e., within 1.3 solar radius, depending on the model parameters. The shock formation is calculated using the well-established wave breaking condition given by the intersection of C+ characteristics in the space-time plane. Our models show that shock heating by slow magnetosonic waves is expected to be relevant at most heights in solar coronal plumes, although slow magnetosonic waves are most likely not a solely operating energy supply mechanism.

  20. Coronal and chromospheric physics

    NASA Technical Reports Server (NTRS)

    Jefferies, J. T.; Landman, D. A.; Orrall, F. Q.

    1983-01-01

    Achievements and completed results are discussed for investigations covering solar activity during the solar maximum mission and the solar maximum year; other studies of solar activity and variability; infrared and submillimeter photometry; solar-related atomic physics; coronal and transition region studies; prominence research; chromospheric research in quiet and active regions; solar dynamics; eclipse studies; and polarimetry and magnetic field measurements. Contributions were also made in defining the photometric filterograph instrument for the solar optical telescope, designing the combined filter spectrograph, and in expressing the scientific aims and implementation of the solar corona diagnostic mission.

  1. Ultraprecision machining of steep aspheric parts with large sagittal height

    NASA Astrophysics Data System (ADS)

    Mu, Lin; Zhao, Rui; Xin, Qiming

    2009-05-01

    Problems occurred during machining steep aspheric parts with large sagittal height on double-spindle diamond turning machine are presented and the main reasons of the problems are described. And methods of solving these problems are also suggested. When we machine steep aspheric parts with large sagittal height on a 2 axis diamond turning machine, we have such problems as difficult control of part edge accuracy, poor roughness and rapid wear of the cutting tool. The main reasons for these problems lie in: 1) Measurement. To make accurate measurements, the measurement range of the profilometer must fall within the sagittal heights of the aspheric parts, and the measurement angle must also meet the requirements, an insufficient measurement angle, for example, will have a big impact on the measurement and fabrication accuracy of such parts; and 2) Machine and tool, firstly, the diamond cutting tool will suffer a very big force when turning the edge section, resulting in bigger micro-vibration in the tool and tool post, thus affecting the part accuracy and surface roughness. Secondly, the machine itself has location errors in axes X and Z during the processing, leading to the severest destruction in the steep section of the aspheric part by their resultant force. Lastly, anisotropy of diamond cutting tool hardness. The indentation hardness of the diamond is maximum in the direction of <1.0.0> of face (100) and the front clearance has the best strength at tool point in the direction of <1.0.0>. When cutting a steep aspheric part with large sagittal height, a bigger included angle of the diamond tool point arc will be used, and there will be a more deviation from the <1.0.0> lattice direction. So the tool hardness is consistently decreased, resulting in a rapid wear of the cutting tool when turning the steep section of the aspheric part, thus the accuracy and roughness in machining an aspheric part become more difficult to control. The paper is concluded with the

  2. Active region coronal evolution

    NASA Technical Reports Server (NTRS)

    Golub, L.; Noci, G.; Poletto, G.; Vaiana, G. S.

    1982-01-01

    Scaling relations between coronal base pressure and longitudinal photospheric magnetic field strength are tested for the case of a single active region observed for five solar rotations from Skylab. The evolution of measureable quantities, such as coronal thermal energy content, total longitudinal photospheric magnetic flux, region scale size, and peak energy density, is traced throughout the five rotations observed. The theoretically derived scaling law of Golub et al. (1980) is found to provide an acceptable fit to the data throughout the entire evolutionary history of the region from an age of about 3 days to the fully evolved state in which the mature active region merges into the general large-scale structure of the quiet corona. An alternative scaling law obtained by including the results of Galeev et al. (1981), however, is found to provide a somewhat better fit to the data. The study is seen as providing additional justification for the belief that magnetic field-related heating is the operative mechanism in the solar corona.

  3. Coronal Magnetic Field Models

    NASA Astrophysics Data System (ADS)

    Wiegelmann, Thomas; Petrie, Gordon J. D.; Riley, Pete

    2015-07-01

    Coronal magnetic field models use photospheric field measurements as boundary condition to model the solar corona. We review in this paper the most common model assumptions, starting from MHD-models, magnetohydrostatics, force-free and finally potential field models. Each model in this list is somewhat less complex than the previous one and makes more restrictive assumptions by neglecting physical effects. The magnetohydrostatic approach neglects time-dependent phenomena and plasma flows, the force-free approach neglects additionally the gradient of the plasma pressure and the gravity force. This leads to the assumption of a vanishing Lorentz force and electric currents are parallel (or anti-parallel) to the magnetic field lines. Finally, the potential field approach neglects also these currents. We outline the main assumptions, benefits and limitations of these models both from a theoretical (how realistic are the models?) and a practical viewpoint (which computer resources to we need?). Finally we address the important problem of noisy and inconsistent photospheric boundary conditions and the possibility of using chromospheric and coronal observations to improve the models.

  4. Temporomandibular joint computed tomography: development of a direct sagittal technique

    SciTech Connect

    van der Kuijl, B.; Vencken, L.M.; de Bont, L.G.; Boering, G. )

    1990-12-01

    Radiology plays an important role in the diagnosis of temporomandibular disorders. Different techniques are used with computed tomography offering simultaneous imaging of bone and soft tissues. It is therefore suited for visualization of the articular disk and may be used in patients with suspected internal derangements and other disorders of the temporomandibular joint. Previous research suggests advantages to direct sagittal scanning, which requires special positioning of the patient and a sophisticated scanning technique. This study describes the development of a new technique of direct sagittal computed tomographic imaging of the temporomandibular joint using a specially designed patient table and internal light visor positioning. No structures other than the patient's head are involved in the imaging process, and misleading artifacts from the arm or the shoulder are eliminated. The use of the scanogram allows precise correction of the condylar axis and selection of exact slice level.

  5. Spinal pedicle subtraction osteotomy for fixed sagittal imbalance patients

    PubMed Central

    Hyun, Seung-Jae; Kim, Yongjung J; Rhim, Seung-Chul

    2013-01-01

    In addressing spinal sagittal imbalance through a posterior approach, the surgeon now may choose from among a variety of osteotomy techniques. Posterior column osteotomies such as the facetectomy or Ponte or Smith-Petersen osteotomy provide the least correction, but can be used at multiple levels with minimal blood loss and a lower operative risk. Pedicle subtraction osteotomies provide nearly 3 times the per-level correction of Ponte/Smith-Petersen osteotomies; however, they carry increased technical demands, longer operative time, and greater blood loss and associated significant morbidity, including neurological injury. The literature focusing on pedicle subtraction osteotomy for fixed sagittal imbalance patients is reviewed. The long-term overall outcomes, surgical tips to reduce the complications and suggestions for their proper application are also provided. PMID:24340276

  6. Congenital muscular torticollis concurrent with sagittal synostosis: a case report.

    PubMed

    Kim, Seung-Hyun; Ahn, Ah-Reum; Yim, Shin-Young

    2014-10-01

    Congenital muscular torticollis (CMT) and craniosynostosis are diseases that cause plagiocephaly and craniofacial asymmetry in children. In our literature review, we did not find any report of concurrent manifestation of CMT and craniosynostosis. A 41-month-old boy visited our hospital with left torticollis, right laterocollis, and craniofacial asymmetry as the main findings. During clinical examination, prominent right sternocleidomastoid muscle and limited range of motion of the neck were noted, and right CMT was confirmed by magnetic resonance imaging of the neck. Three-dimensional computed tomography of the skull, which was conducted due to the unusual appearance of the skull with a large head circumference, mild brachycephaly, as well as left plagiocephaly, revealed premature closure of the sagittal suture. Thus, we report the first case that showed concurrence of CMT and sagittal synostosis. We recommend that concurrently manifested craniosynostosis needs to be examined if the subject with CMT displays unusual craniofacial asymmetry to a greater extent than deformational plagiocephaly. PMID:25379504

  7. Force-Induced Craniosynostosis in the Murine Sagittal Suture

    PubMed Central

    Oppenheimer, Adam J.; Rhee, Samuel T.; Goldstein, Steven A.; Buchman, Steven R.

    2010-01-01

    BACKGROUND The etiology of non-syndromic craniosynostosis remains elusive. While compressive forces have been implicated in premature suture fusion, conclusive evidence of force-induced craniosynostosis is lacking. The purpose of this study was to determine if cyclical loading of the murine calvarium could induce suture fusion. METHODS Calvarial coupons from post-natal day 21, B6CBA wild-type mice (n = 18) were harvested and cultured. A custom appliance capable of delivering controlled, cyclical, compressive loads was applied perpendicular to the sagittal suture within the coupon in vitro. Nine coupons were subjected to 0.3g of force for 30 minutes each day for a total of 14 days. A control group of nine coupons was clamped in the appliance without loading. Analysis of suture phenotype was performed using alkaline phosphatase and H&E staining techniques, as well as in situ hybridization analysis using Bone Sialoprotein (BSP). RESULTS Control group sagittal sutures—which normally remain patent in mice—showed their customary histological appearance. In contradistinction, sagittal sutures subjected to cyclic loading showed histological evidence of premature fusion (craniosynostosis). In addition, alkaline phosphatase activity and BSP expression was observed to be increased in the experimental group when compared to matched controls. CONCLUSIONS An in vitro model of forced-induced craniosynostosis has been devised. Premature fusion of the murine sagittal suture was induced with the application of controlled, cyclical, compressive loads. These results implicate abnormal forces in the development of non-syndromic craniosynostosis, which supports our global hypothesis that epigenetic phenomena have a crucial role in the pathogenesis of craniosynostosis. PMID:19952640

  8. Traumatic Thumb Radial Sagittal Band Injury Mimicking EPL Rupture.

    PubMed

    Dissanayake, Ravi M; Moore, Peter; McCarten, Gregory M

    2016-06-01

    We present the case of a closed traumatic disruption of the thumb radial sagittal band (RSB) that sonographically mimicked rupture of the extensor pollicis longus (EPL) tendon. This injury was treated with primary repair of the RSB and lead to a good functional outcome for the patient. This case report highlights how early recognition and treatment can lead to a good functional outcome. PMID:27454647

  9. Out-of-ecliptic studies of coronal holes and their relation to the solar wind. [project planning for solar probes to study solar activity

    NASA Technical Reports Server (NTRS)

    Noyes, R. W.

    1976-01-01

    The advantages of observing coronal holes of the sun above the solar ecliptic plane by a solar probe are discussed. Also discussed are the size of coronal holes, their temperature, and magnetic fields associated with the holes. The role of coronal holes in contributing to the solar wind is examined. Data and observations on coronal holes from Skylab and OSO are treated. It is concluded that an out-of-the-ecliptic solar probe mission would greatly add to the understanding of coronal holes (at high latitudes) thus adding a new perspective to the observation of these phenomena. (Photographs of the sun taken by Skylab are shown).

  10. The Geometric Spreading of Coronal Plumes and Coronal Holes

    NASA Technical Reports Server (NTRS)

    Suess, S. T.; Poletto, G.; Wang, A. - H.; Wu, S. T.; Cuseri, I.

    1997-01-01

    The geometric spreading in plumes and in the interplume region in coronal holes is calculated, using analytic and numerical theoretical models, between 1.0 and 5.0 solar radius. We apply two scale approximation that permits the rapid local spreading at the base of plumes to be evaluated separately from the global spreading imposed by coronal hole geometry. We show that fl can be computed from a potential field model and fg can be computed from global magnetohydrodynamic simulations of coronal structure. The approximations are valid when the plasma beta is small with respect to unity and for a plume separation small with respect to a solar radius.

  11. The Coronal Solar Magnetism Observatory

    NASA Astrophysics Data System (ADS)

    Tomczyk, S.; Landi, E.; Zhang, J.; Lin, H.; DeLuca, E. E.

    2015-12-01

    Measurements of coronal and chromospheric magnetic fields are arguably the most important observables required for advances in our understanding of the processes responsible for coronal heating, coronal dynamics and the generation of space weather that affects communications, GPS systems, space flight, and power transmission. The Coronal Solar Magnetism Observatory (COSMO) is a proposed ground-based suite of instruments designed for routine study of coronal and chromospheric magnetic fields and their environment, and to understand the formation of coronal mass ejections (CME) and their relation to other forms of solar activity. This new facility will be operated by the High Altitude Observatory of the National Center for Atmospheric Research (HAO/NCAR) with partners at the University of Michigan, the University of Hawaii and George Mason University in support of the solar and heliospheric community. It will replace the current NCAR Mauna Loa Solar Observatory (http://mlso.hao.ucar.edu). COSMO will enhance the value of existing and new observatories on the ground and in space by providing unique and crucial observations of the global coronal and chromospheric magnetic field and its evolution. The design and current status of the COSMO will be reviewed.

  12. The coronal fricative problem

    PubMed Central

    Dinnsen, Daniel A.; Dow, Michael C.; Gierut, Judith A.; Morrisette, Michele L.; Green, Christopher R.

    2013-01-01

    This paper examines a range of predicted versus attested error patterns involving coronal fricatives (e.g. [s, z, θ, ð]) as targets and repairs in the early sound systems of monolingual English-acquiring children. Typological results are reported from a cross-sectional study of 234 children with phonological delays (ages 3 years; 0 months to 7;9). Our analyses revealed different instantiations of a putative developmental conspiracy within and across children. Supplemental longitudinal evidence is also presented that replicates the cross-sectional results, offering further insight into the life-cycle of the conspiracy. Several of the observed typological anomalies are argued to follow from a modified version of Optimality Theory with Candidate Chains (McCarthy, 2007). PMID:24790247

  13. The coronal fricative problem.

    PubMed

    Dinnsen, Daniel A; Dow, Michael C; Gierut, Judith A; Morrisette, Michele L; Green, Christopher R

    2013-07-01

    This paper examines a range of predicted versus attested error patterns involving coronal fricatives (e.g. [s, z, θ, ð]) as targets and repairs in the early sound systems of monolingual English-acquiring children. Typological results are reported from a cross-sectional study of 234 children with phonological delays (ages 3 years; 0 months to 7;9). Our analyses revealed different instantiations of a putative developmental conspiracy within and across children. Supplemental longitudinal evidence is also presented that replicates the cross-sectional results, offering further insight into the life-cycle of the conspiracy. Several of the observed typological anomalies are argued to follow from a modified version of Optimality Theory with Candidate Chains (McCarthy, 2007). PMID:24790247

  14. Coronal transient--eruptive prominence of 1980 August 5

    SciTech Connect

    Fisher, R.; Garcia, C.J.; Seagraves, P.

    1981-06-15

    A coronal transient was observed in association with an eruptive prominence event using the Mauna Loa experiment system. The transient, a rarefaction, formed before the acceleration of the eruptive prominence. Upward velocities of various features, as seen in the plane of the sky, show a marked difference as a function of time between the transient and the eruptive prominence. A region of enhanced electron density formed slowly in front of the rarefaction.

  15. Maxillomandibular Advancement in Obstructive Sleep Apnea Syndrome Patients: a Restrospective Study on the Sagittal Cephalometric Variables

    PubMed Central

    Ronchi, Paolo; Ambrosoli, Alessandro; Caprioglio, Alberto

    2013-01-01

    ABSTRACT Objectives The present retrospective study analyzes sagittal cephalometric changes in patients affected by obstructive sleep apnea syndrome submitted to maxillomandubular advancement. Material and Methods 15 adult sleep apnea syndrome (OSAS) patients diagnosed by polysomnography (PSG) and treated with maxillomandubular advancement (MMA) were included in this study. Pre- (T1) and postsurgical (T2) PSG studies assessing the apnea/hypopnea index (AHI) and the lowest oxygen saturation (LSAT) level were compared. Lateral cephalometric radiographs at T1 and T2 measuring sagittal cephalometric variables (SNA, SNB, and ANB) were analyzed, as were the amount of maxillary and mandibular advancement (Co-A and Co-Pog), the distance from the mandibular plane to the most anterior point of the hyoid bone (Mp-H), and the posterior airway space (PAS). Results Postoperatively, the overall mean AHI dropped from 58.7 ± 16 to 8.1 ± 7.8 events per hour (P < 0.001). The mean preoperative LSAT increased from 71% preoperatively to 90% after surgery (P < 0.001). All the patients in our study were successfully treated (AHI < 20 or reduced by 50%). Cephalometric analysis performed after surgery showed a statistically significant correlation between the mean SNA variation and the decrease in the AHI (P = 0.01). The overall mean SNA increase was 6°. Conclusions Our findings suggest that the improvement observed in the respiratory symptoms, namely the apnea/hypopnea episodes, is correlated with the SNA increase after surgery. This finding may help maxillofacial surgeons to establish selective criteria for the surgical approach to sleep apnea syndrome patients. PMID:24422033

  16. Three-dimensional Effect of the Single Plane Proximal Femur Osteotomy

    PubMed Central

    2015-01-01

    Purpose Three-dimensional (3D) effects of the single plane osteotomies of the proximal femur are compared and analyzed by the trigonometric method. Materials and Methods The shape of proximal femur was simplified as a bent line. The bent line is the continuation of the three points-the center of the femoral head, the center of femoral neck at the base, and the center of the femoral shaft. Then rotated the proximal femur at the junction of the neck and shaft with the each rotation axis of X, Y, Z, defined the frontal plane as a XY plane, sagittal plane as a YZ plane, and transverse plane as a XZ plane. Results The varus osteotomy of the proximal femur in the frontal plane with the rotation axis 'Z' that meant the increase of the X coordinate and the decrease of Y coordinate with constant Z coordinate (Δx>Δy, Δz=0) resulted in decreased anteversion in the transverse plane and increased flexion in the sagittal plane. The derotation osteotomy (Δx>Δz, Δy=0) resulted in varus in the frontal plane and extension in the sagittal plane. The flexion osteotomy (Δz>Δy, Δx=0) resulted in increased anteversion in the transverse plane and varus in the frontal plane. Conclusion Single plane osteotomy for the proximal femur results in the angular correction in all three planes and may have the similar 3D effect of the certain double or triple osteotomy. So single plane osteotomy could be enough to correct some complex deformities.

  17. Waves in Solar Coronal Loops

    NASA Astrophysics Data System (ADS)

    Wang, T. J.

    2016-02-01

    The corona is visible in the optical band only during a total solar eclipse or with a coronagraph. Coronal loops are believed to be plasma-filled closed magnetic flux anchored in the photosphere. Based on the temperature regime, they are generally classified into cool, warm, and hot loops. The magnetized coronal structures support propagation of various types of magnetohydrodynamics (MHD) waves. This chapter reviews the recent progress made in studies based on observations of four types of wave phenomena mainly occurring in coronal loops of active regions, including: flare-excited slow-mode waves; impulsively excited kink-mode waves; propagating slow magnetoacoustic waves; and ubiquitous propagating kink (Alfvénic) waves. This review not only comprehensively discusses these waves and coronal seismology but also topics that are newly emerging or hotly debated in order to provide the reader with useful guidance on further studies.

  18. A reflection on radiographic cephalometry: the evaluation of sagittal discrepancy.

    PubMed

    Duterloo, Herman S

    2014-09-01

    A critical review is presented of the basic properties and applications of cephalometry as a clinical tool with a focus on the evaluation of sagittal discrepancy. Diagnostic cephalometric assessments are subjective and not based on evidence. To assess individual skeletal and/or facial soft tissue form subjectively, selected norms are used. Norms have been developed for various ethnical groups to improve clinical applicability, but subjectivity remains. That subjectivity precludes application of a modern review system, making the present review a personal account. The cephalometric evaluation of sagittal discrepancy finds its historic origin in the Angle classification. Recent publications try to improve accuracy in classifying sagittal discrepancy. It remains unclear in what sense such efforts influence treatment decisions and/or treatment effect. Almost all selected landmarks are located on or dependent upon periosteal/endosteal bone image contours. Their homology is based on circumstantial reasoning and stability over time, which is implicitly assumed. However, implant growth studies and histological investigations show most landmarks to be unstable, as they are involved in displacement and bone remodelling. These landmarks are therefore heterologous when used for individual evaluation of change over time. Notwithstanding the above-indicated limitations, diagnostic cephalometric assessments are clinically useful and help to develop perceptions of balance and harmony and communication between colleagues and patients. There is no evidence-based method to prefer one particular diagnostic method. Landmark location accuracy and geometric issues do not play a decisive role. The subjective characteristic of diagnostic evaluations limits their power to size/shape comparisons. Structural superimposition is the valid biologically evidence-based method to provide advanced insight in individual growth and/or treatment changes and their variations. PMID:24521748

  19. Dynamical behaviour in coronal loops

    NASA Technical Reports Server (NTRS)

    Haisch, Bernhard M.

    1986-01-01

    Rapid variability has been found in two active region coronal loops observed by the X-ray Polychromator (XRP) and the Hard X-ray Imaging Spectrometer (HXIS) onboard the Solar Maximum Mission (SMM). There appear to be surprisingly few observations of the short-time scale behavior of hot loops, and the evidence presented herein lends support to the hypothesis that coronal heating may be impulsive and driven by flaring.

  20. Solar and stellar coronal plasmas

    NASA Technical Reports Server (NTRS)

    Golub, L.

    1985-01-01

    Progress made in describing and interpreting coronal plasma processes and the relationship between the solar corona and its stellar counterparts is reported. Topics covered include: stellar X-ray emission, HEAO 2 X-ray survey of the Pleiades, closed coronal structures, X-ray survey of main-sequence stars with shallow convection zones, implications of the 1400 MHz flare emission, and magnetic field stochasticity.

  1. Sagittal Spinal Morphology in Highly Trained Adolescent Tennis Players

    PubMed Central

    Muyor, José M.; Sánchez-Sánchez, Estefanía; Sanz-Rivas, David; López-Miñarro, Pedro A.

    2013-01-01

    Sports with a predominance of forward-bending and extension postures have been associated with alterations in the sagittal spinal curvatures and greater risk of spinal injury. Because, the tennis players adopt these postures, the aims of this study were: 1) to describe spinal curvatures and pelvic tilt in male and female highly trained adolescent tennis players during relaxed standing posture and with thoracic spine corrected (in prone lying on the floor); and 2) to determine the frequency of thoracic hyperkyphosis and lumbar hypo/hyper lordosis in these postures. Forty adolescent tennis players (24 male and 16 female) aged 13-18 years, participated voluntarily in this study. The Spinal Mouse system was used to measure sagittal spinal curvatures and pelvic tilt. The mean values in the relaxed standing posture were 43.83° ± 7.87° (thoracic kyphosis), - 27.58° ± 7.01° (lumbar lordosis), and 13.38° ± 5.57° (pelvic tilt) for male tennis players, respectively; and 36.13° ± 6.69° (thoracic kyphosis), - 32.69° ± 5.06° (lumbar lordosis), 20.94° ± 5.36° (pelvic tilt) for female tennis players (p < 0.05 between genders in all spinal parameters). The male and female tennis players showed a frequency of 62.5% and 93.8% (p = 0.032) for neutral thoracic kyphosis, and 83.3% and 93.8% (p = 0.062) in neutral lumbar lordosis, respectively. In conclusion, due to the high percentage of neutral spinal curvatures in both male and female tennis players, to practice tennis in these levels does not alter sagittal spinal morphology in the relaxed standing posture in adolescent highly trained tennis players. Key Points This study evaluated thoracic and lumbar spinal curvatures and pelvic tilt during several postures in young highly trained tennis players. Female tennis players showed statistically significant greater anterior pelvic tilt, lumbar lordosis and lower thoracic kyphosis than male tennis players. The high percentage of neutral thoracic kyphosis and lumbar

  2. Mandibular nerve schwannoma resection using sagittal split ramus osteotomy.

    PubMed

    Mahmood, Laith; Demian, Nagi; Weinstock, Yitzchak E; Weissferdt, Annikka

    2013-11-01

    A case is presented of a unique presentation and treatment of a mandibular nerve schwannoma. Its uniqueness stems from the fact that it consisted of 2 distinct tumors along the same nerve: one within the body of the mandible and the other within the ipsilateral pterygomandibular space. Rather than the standard approach of lip split and hemimandibulectomy, a unique approach of a sagittal split ramus osteotomy was used that allowed access to the 2 lesions and avoided the added morbidity of the former approach. The 2 portions of the lesion were successfully removed and the patient was satisfied with the result. Recurrence has not been detected after 6 months. PMID:23891013

  3. Bilambdoid and posterior sagittal synostosis: the Mercedes Benz syndrome.

    PubMed

    Moore, M H; Abbott, A H; Netherway, D J; Menard, R; Hanieh, A

    1998-09-01

    A consistent pattern of craniosynostosis in the sagittal and bilateral lambdoid sutures is described in three patients. The external cranial ridging associated with fusion of these sutures produces a characteristic triradiate, or "Mercedes Benz," appearance to the posterior skull. Locally marked growth restriction is evident in the posterior fossa with compensatory secondary expansion of the anterior fossa manifesting a degree of frontal bossing which mimics bicoronal synostosis. Although this appearance could lead to inadvertent surgery in the frontal region, attention to the occipital region with wide early suture excision and vault shaping is indicated. PMID:9780908

  4. Dynamic sagittal flexibility coefficients of the human cervical spine.

    PubMed

    Ivancic, Paul C; Ito, Shigeki; Panjabi, Manohar M

    2007-07-01

    The goal of the present study was to determine the dynamic sagittal flexibility coefficients, including coupling coefficients, throughout the human cervical spine using rear impacts. A biofidelic whole cervical spine model (n=6) with muscle force replication and surrogate head was rear impacted at 5 g peak horizontal accelerations of the T1 vertebra within a bench-top mini-sled. The dynamic main and coupling sagittal flexibility coefficients were calculated at each spinal level, head/C1 to C7/T1. The average flexibility coefficients were statistically compared (p<0.05) throughout the cervical spine. To validate the coefficients, the average computed displacement peaks, obtained using the average flexibility matrices and the measured load vectors, were statistically compared to the measured displacement peaks. The computed and measured displacement peaks showed good overall agreement, thus validating the computed flexibility coefficients. These peaks could not be statistically differentiated, with the exception of extension rotation at head/C1 and posterior shear translation at C7/T1. Head/C1 was significantly more flexible than all other spinal levels. The cervical spine was generally more flexible in posterior shear, as compared to axial compression. The coupling coefficients indicated that extension moment caused coupled posterior shear translation while posterior shear force caused coupled extension rotation. The present results may be used towards the designs of anthropometric test dummies and mathematical models that better simulate the cervical spine response during dynamic loading. PMID:17140545

  5. Coronal structure and the solar wind

    NASA Technical Reports Server (NTRS)

    Roelof, E. C.

    1974-01-01

    Aspects concerning the open coronal structure and geomagnetic disturbances are considered along with the general coronal emission characteristics and relations between the open coronal structure and the interplanetary field. The nonstatistical indicators of coronal structure are examined and questions are investigated regarding the accuracy obtained in the determination of the emission latitude and longitude in the high corona for plasma, fields, and particles. Attention is given to the problem of particle population organization by low-coronal neutral line structures in the absence of a high coronal polarity structure.

  6. Skeletal Stability after Large Mandibular Advancement (> 10 mm) with Bilateral Sagittal Split Osteotomy and Skeletal Elastic Intermaxillary Fixation

    PubMed Central

    Rodrigo-Domingo, Maria; Jensen, Thomas

    2016-01-01

    ABSTRACT Objectives The aim of the present study was to assess the skeletal stability after large mandibular advancement (> 10 mm) with bilateral sagittal split osteotomy and skeletal elastic intermaxillary fixation and to correlate the skeletal stability with the vertical facial type. Material and Methods A total of 33 consecutive patients underwent bimaxillary surgery to correct skeletal Class II malocclusion with a mandibular advancement (> 10 mm) measured at B-point and postoperative skeletal elastic intermaxillary fixation for 16 weeks. Skeletal stability was evaluated using lateral cephalometric radiographs obtained preoperative (T1), 8 weeks postoperatively (T2), and 18 month postoperatively (T3). B-point and pogonion (Pog) was used to measure the skeletal relapse and the mandibular plane angle (MP-angle) was used to determine the vertical facial type. Results The mean advancement from T1 to T2 were 11.6 mm and 13.5 mm at B-point and Pog, respectively. The mean skeletal relapse from T2 to T3 was -1.3 mm at B-point and -1.6 mm at Pog. The nineteen patients characterized as long facial types, showed the highest amount of skeletal relapse (-1.5 mm at B-point and -1.9 mm at Pog). Conclusions The present study showed a limited amount of skeletal relapse in large mandibular advancement (> 10 mm) with bilateral sagittal split osteotomy and skeletal elastic intermaxillary fixation. Bilateral sagittal split osteotomy in combination with skeletal intermaxillary fixation can therefore be an alternative to distraction osteogenesis in large mandibular advancements. PMID:27489609

  7. Coronal View Ultrasound Imaging of Movement in Different Segments of the Tongue during Paced Recital: Findings from Four Normal Speakers and a Speaker with Partial Glossectomy

    ERIC Educational Resources Information Center

    Bressmann, Tim; Flowers, Heather; Wong, Willy; Irish, Jonathan C.

    2010-01-01

    The goal of this study was to quantitatively describe aspects of coronal tongue movement in different anatomical regions of the tongue. Four normal speakers and a speaker with partial glossectomy read four repetitions of a metronome-paced poem. Their tongue movement was recorded in four coronal planes using two-dimensional B-mode ultrasound…

  8. The Geometric Spreading of Coronal Plumes and Coronal Holes

    NASA Technical Reports Server (NTRS)

    Suess, S. T.; Poletto, G.; Wang, A.-H.; Wu, S. T.; Cuseri, I.

    1998-01-01

    The geometric spreading in plumes and in the interplume region in coronal holes is calculated, using analytic and numerical theoretical models, between 1.0 and 5.0 solar radius. We apply a two-scale approximation that permits the rapid local spreading at the base of plumes (f(sub t)) to be evaluated separately from the global spreading (f(sub g)) imposed by coronal hole geometry. We show that f(sub t) can be computed from a potential-field model and f(sub g) can be computed from global magnetohydrodynamic simulations of coronal structure. The approximations are valid when the plasma beta is mail with respect to unity and for a plume separation small with respect to a solar radius.

  9. Key aspects of coronal heating

    PubMed Central

    Klimchuk, James A.

    2015-01-01

    We highlight 10 key aspects of coronal heating that must be understood before we can consider the problem to be solved. (1) All coronal heating is impulsive. (2) The details of coronal heating matter. (3) The corona is filled with elemental magnetic stands. (4) The corona is densely populated with current sheets. (5) The strands must reconnect to prevent an infinite build-up of stress. (6) Nanoflares repeat with different frequencies. (7) What is the characteristic magnitude of energy release? (8) What causes the collective behaviour responsible for loops? (9) What are the onset conditions for energy release? (10) Chromospheric nanoflares are not a primary source of coronal plasma. Significant progress in solving the coronal heating problem will require coordination of approaches: observational studies, field-aligned hydrodynamic simulations, large-scale and localized three-dimensional magnetohydrodynamic simulations, and possibly also kinetic simulations. There is a unique value to each of these approaches, and the community must strive to coordinate better. PMID:25897094

  10. Significance of Coronal Proset Magnetic Resonance Imaging to Detect Hidden Zone of the Mid-Zone Stenosis in the Lumbar Spine and Morphometric Analysis of the Mid-Zone Stenosis

    PubMed Central

    Ahn, Hyo-Sae; Son, Whee Sung; Shin, Ji-Hoon; Ahn, Myun-Whan

    2016-01-01

    Study Design Retrospective exploratory imaging study. Purpose To investigate the significance of the coronal magnetic resonance imaging (MRI) using Proset technique to detect the hidden zone in patients with mid-zone stenosis by comparing with conventional axial and sagittal MRI and to explore the morphologic characteristic patterns of the mid-zone stenosis. Overview of Literature Despite advancements in diagnostic modalities such as computed tomography and MRI, stenotic lesions under the pedicle and pars interarticularis, also called the mid-zone, are still difficult to definitely detect with the conventional axial and sagittal MRI due to its inherited anatomical peculiarity. Methods Of 180 patients scheduled to undergo selective nerve root block, 20 patients with mid-zone stenosis were analyzed using MRI. Characteristic group patterns were also explored morphologically by comparing MRI views of each group after verifying statistical differences between them. Hierarchical cluster analysis was performed to classify morphological characteristic groups based on three-dimensional radiologic grade for stenosis at all three zones. Results At the mid-zone, the stenosis of grade 2 or more was found in 14 cases in the coronal image,13 cases in the sagittal image, and 9 cases in the axial image (p<0.05). Especially, mid-zone stenosis was not detected in six of 20 cases at the axial images. At the entrance and exit-zone, coronal image was also associated with more accurate detection of hidden zone compared to other views such as axial and sagittal images. After repeated statistical verification, the morphological patterns of hidden zone were classified into 5 groups: 6 cases in group I; 1 case in group II; 4 cases in group III; 7 cases in group IV; and 2 cases in group V. Conclusions Coronal MRI using the Proset technique more accurately detected hidden zone of the mid-zone stenosis compared to conventional axial and sagittal images. PMID:27559443

  11. Sagittal synostosis: I. Preoperative morphology of the skull.

    PubMed

    Guimarães-Ferreira, José; Gewalli, Fredrik; David, Lisa; Darvann, Tron A; Hermann, Nuno V; Kreiborg, Sven; Friede, Hans; Lauritzen, Claes G K

    2006-01-01

    The aim of this study was to characterise the preoperative morphology of the skull in sagittal synostosis in an objective and quantified way. The shapes of the skulls of 105 patients with isolated premature synostosis of the sagittal suture (SS group) were studied and compared with those of a control group of 72 children with unilateral incomplete cleft lip (UICL). A standardised radiocephalometric technique was used to obtain the images. A modification of a method developed by Kreiborg was used to analyse the radiocephalograms, which included the digitisation of 88 landmarks in the calvaria, skull base, and orbit (42 in the lateral and 46 in the frontal projections), the production of plots of mean shape for each group, and the intergroup comparison of a series of 81 variables (linear distance between selected landmarks, and angles defined by groups of three landmarks). Data from a subgroup of 66 patients aged 5 to 8 months were further compared to age-matched normative data in terms of seven angular and linear calvarial, cranial base and orbital variables. In a comparative analysis of the mean lateral plots, the foreheads of the study group (SS) had a more pronounced anterior slope and were also more convex. The vertex area was located more anteriorly, and was less convex. The occipital curvature was more prominent. Analysis of the mean frontal plots revealed a lack in convexity and lateral projection of the upper parietal regions, as well as a lower location of the line of maximum skull width. Comparison of the mean values of an SS subgroup to age-matched normative data showed a longer (p<0.001) and narrower skull (p<0.001) and a greater interorbital distance (p<0.001). The cranial base angle, the sella to nasion, and sella to basion lengths did not differ significantly. Sagittal synostosis is characterised by an extensive deformity of the cranial vault, with an essentially normal cranial base. The widened interorbital distance is probably related to

  12. Comprehensive Analysis of Mandibular Residual Asymmetry after Bilateral Sagittal Split Ramus Osteotomy Correction of Menton Point Deviation

    PubMed Central

    Lin, Qiuping; Huang, Xiaoqiong; Xu, Yue; Yang, Xiaoping

    2016-01-01

    Purpose Facial asymmetry often persists even after mandibular deviation corrected by the bilateral sagittal split ramus osteotomy (BSSRO) operation, since the reference facial sagittal plane for the asymmetry analysis is usually set up before the mandibular menton (Me) point correction. Our aim is to develop a predictive and quantitative method to assess the true asymmetry of the mandible after a midline correction performed by a virtual BSSRO, and to verify its availability by evaluation of the post-surgical improvement. Patients and Methods A retrospective cohort study was conducted at the Hospital of Stomatology, Sun Yat-sen University (China) of patients with pure hemi-mandibular elongation (HE) from September 2010 through May 2014. Mandibular models were reconstructed from CBCT images of patients with pre-surgical orthodontic treatment. After mandibular de-rotation and midline alignment with virtual BSSRO, the elongation hemi-mandible was virtually mirrored along the facial sagittal plane. The residual asymmetry, defined as the superimposition and boolean operation of the mirrored elongation side on the normal side, was calculated, including the volumetric differences and the length of transversal and vertical asymmetry discrepancy. For more specific evaluation, both sides of the hemi-mandible were divided into the symphysis and parasymphysis (SP), mandibular body (MB), and mandibular angle (MA) regions. Other clinical variables include deviation of Me point, dental midline and molar relationship. The measurement of volumetric discrepancy between the two sides of post-surgical hemi-mandible were also calculated to verify the availability of virtual surgery. Paired t-tests were computed and the P value was set at .05. Results This study included 45 patients. The volume differences were 407.8±64.8 mm3, 2139.1±72.5 mm3, and 422.5±36.9 mm3; residual average transversal discrepancy, 1.9 mm, 1.0 mm, and 2.2 mm; average vertical discrepancy, 1.1 mm, 2.2 mm, and 2

  13. Lower Extremity Energy Absorption and Biomechanics During Landing, Part II: Frontal-Plane Energy Analyses and Interplanar Relationships

    PubMed Central

    Norcross, Marc F.; Lewek, Michael D.; Padua, Darin A.; Shultz, Sandra J.; Weinhold, Paul S.; Blackburn, J. Troy

    2013-01-01

    Context: Greater sagittal-plane energy absorption (EA) during the initial impact phase (INI) of landing is consistent with sagittal-plane biomechanics that likely increase anterior cruciate ligament (ACL) loading, but it does not appear to influence frontal-plane biomechanics. We do not know whether frontal-plane INI EA is related to high-risk frontal-plane biomechanics. Objective: To compare biomechanics among INI EA groups, determine if women are represented more in the high group, and evaluate interplanar INI EA relationships. Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: Participants included 82 (41 men, 41 women; age = 21.0 ± 2.4 years, height = 1.74 ± 0.10 m, mass = 70.3 ± 16.1 kg) healthy, physically active volunteers. Intervention(s): We assessed landing biomechanics with an electromagnetic motion-capture system and force plate. Main Outcome Measure(s): We calculated frontal- and sagittal-plane total, hip, knee, and ankle INI EA. Total frontal-plane INI EA was used to create high, moderate, and low tertiles. Frontal-plane knee and hip kinematics, peak vertical and posterior ground reaction forces, and peak internal knee-varus moment (pKVM) were identified and compared across groups using 1-way analyses of variance. We used a χ2 analysis to evaluate male and female allocation to INI EA groups. We used simple, bivariate Pearson product moment correlations to assess interplanar INI EA relationships. Results: The high–INI EA group exhibited greater knee valgus at ground contact, hip adduction at pKVM, and peak hip adduction than the low–INI EA group (P < .05) and greater peak knee valgus, pKVM, and knee valgus at pKVM than the moderate– (P < .05) and low– (P < .05) INI EA groups. Women were more likely than men to be in the high–INI EA group (χ2 = 4.909, P = .03). Sagittal-plane knee and frontal-plane hip INI EA (r = 0.301, P = .006) and sagittal-plane and frontal-plane ankle INI EA were

  14. Solar and stellar coronal plasmas

    NASA Technical Reports Server (NTRS)

    Golub, Leon

    1989-01-01

    Progress in observational, theoretical, and radio studies of coronal plasmas is summarized. Specifically work completed in the area of solar and stellar magnetic fields, related photospheric phenomena and the relationships between magnetism, rotation, coronal and chromospheric emission in solar-like stars is described. Also outlined are theoretical studies carried out in the following areas, among others: (1) neutral beams as the dominant energy transport mechanism in two ribbon-flares; (2) magneto hydrodynamic and circuit models for filament eruptions; and (3) studies of radio emission mechanisms in transient events. Finally, radio observations designed for coronal activity studies of the sun and of solar-type coronae are described. A bibliography of publications and talks is provided along with reprints of selected articles.

  15. Solar Coronal Structure Study

    NASA Technical Reports Server (NTRS)

    Nitta, Nariaki; Bruner, Marilyn E.; Saba, Julia; Strong, Keith; Harvey, Karen

    2000-01-01

    The subject of this investigation is to study the physics of the solar corona through the analysis of the EUV and UV data produced by two flights (12 May 1992 and 25 April 1994) of the Lockheed Solar Plasma Diagnostics Experiment (SPDE) sounding rocket payload, in combination with Yohkoh and ground-based data. Each rocket flight produced both spectral and imaging data. These joint datasets are useful for understanding the physical state of various features in the solar atmosphere at different heights ranging from the photosphere to the corona at the time of the, rocket flights, which took place during the declining phase of a solar cycle, 2-4 years before the minimum. The investigation is narrowly focused on comparing the physics of small- and medium-scale strong-field structures with that of large-scale, weak fields. As we close th is investigation, we have to recall that our present position in the understanding of basic solar physics problems (such as coronal heating) is much different from that in 1995 (when we proposed this investigation), due largely to the great success of SOHO and TRACE. In other words, several topics and techniques we proposed can now be better realized with data from these missions. For this reason, at some point of our work, we started concentrating on the 1992 data, which are more unique and have more supporting data. As a result, we discontinued the investigation on small-scale structures, i.e., bright points, since high-resolution TRACE images have addressed more important physics than SPDE EUV images could do. In the final year, we still spent long time calibrating the 1992 data. The work was complicated because of the old-fashioned film, which had problems not encountered with more modern CCD detectors. After our considerable effort on calibration, we were able to focus on several scientific topics, relying heavily on the SPDE UV images. They include the relation between filaments and filament channels, the identification of hot

  16. Unilateral sagittal split mandibular ramus osteotomy: indications and geometry.

    PubMed

    Beukes, Jacques; Reyneke, Johan P; Damstra, Janalt

    2016-02-01

    Small mandibular asymmetries may be corrected by unilateral sagittal split ramus osteotomy (USSO). This study had two objectives: first to define the geometric changes in the mandibular condyle and the lower incisor teeth that result from the rotation of the major segment (n=26), and secondly to examine in a clinical study the temporomandibular joints (TMJ) of 23 patients after correction of mandibular asymmetry by USSO to find out if there were any long-term adverse effects. Small mandibular asymmetries (<5mm) can be corrected by USSO. Secondary anteroposterior changes as a result of setback or advancement on the operated side should be taken into account during the planning of treatment. The small rotational changes of the condyle did not adversely affect the TMJ. PMID:26774360

  17. [Mandibular advancement: bilateral sagittal split versus -distraction osteogenesis].

    PubMed

    Akkerman, V; Ho, J P; Baas, E M; de Lange, J de

    2015-11-01

    In the 1990s intra-oral distraction osteogenesis (DO) became available as an alternative for bilateral sagittal splitosteotomy (BSSO) for advancement of the mandible. It was thought that DO would lead to more stability in the results and fewer neurosensory disturbances of the inferior alveolar nerve. However, there was no scientific evidence for this assumption. This article describes a number of recently published, prospective studies that demonstrate that BSSO is not inferior to DO with respect to stability and neurosensory disturbances of the inferior alveolar nerve. They also demonstrate that BSSO leads to less pain in patients and to lower total costs. It can be concluded that BSSO should be considered the standard therapy for mandibular advancement up to 10 mm in non-syndromal patients. PMID:26569001

  18. Nonclosure of rectourethral fistula during posterior sagittal anorectoplasty: Our experience

    PubMed Central

    Jadhav, Sudhakar; Raut, Amit; Mandke, Jui; Patil, Santosh; Vora, Ravindra; Kittur, Dinesh

    2013-01-01

    Aim: To study the effect of nonclosure of rectourethral (RU) fistula and to do a comparative analysis of the complications with and without nonclosure of RU fistula during posterior sagittal anorectoplasty (PSARP) in anorectal malformation cases (ARM). Materials and Methods: A total of 68 cases of ARM were included in the study group, of which 34 cases were those in whom RU fistula was not closed (group A) during PSARP. Another 34 successive cases were included in study group B in whom the RU fistula was closed as is conventionally done by using interrupted sutures. Results: Comparatively, group A had none or minimum urological complications as compared to Group B. Conclusion: RU fistula closure is not mandatory during PSARP and nonclosure avoids urological complications. It especially avoids urethral complications, which are 100% preventable. PMID:23599574

  19. Developing a Sagittally Focusing Double-Multilayer Monochromator

    NASA Astrophysics Data System (ADS)

    Wang, Yujie; Narayanan, Suresh; Liu, Jinyuan; Shu, Deming; Wang, Jin

    2007-01-01

    We report the development of a sagittally focusing double multilayer monochromator to produce a spatially extended, wide-bandpass x-ray beam from intense synchrotron bending-magnet source at the Advanced Photon Source for ultrafast x-radiography and -tomography applications. This monochromator consists of the two W/B4C multilayers with a 25-Å periodicity coated on Si single-crystal substrates. The second crystal is mounted on a saggitally focusing bender which can; dynamically change the bending radius of the crystal in order to focus the beam to various points along the beamline. With this new apparatus, it becomes possible to adjust the x-ray beam size to best match the area detector size and the object size to facilitate a more efficient data collection using ultrafast x-radiography and -tomography.

  20. Superior sagittal sinus thrombosis complicating typhoid Fever in a teenager.

    PubMed

    Okunola, P O; Ofovwe, G E; Abiodun, M T; Azunna, C P

    2012-01-01

    Cerebral venous sinus (sinovenous) thrombosis (CSVT) is a rare life-threatening disorder in childhood that is often misdiagnosed. CSVT encompasses cavernous sinus thrombosis, lateral sinus thrombosis, and superior sagittal sinus thrombosis (SSST). We present an adolescent girl who was well until two weeks earlier when she had a throbbing frontal headache and fever with chills; she later had dyspnoea, jaundice, melena stool, multiple seizures, nuchal rigidity, and monoparesis of the right lower limb a day before admission. Urine test for Salmonella typhi Vi antigen was positive, and Widal reaction was significant. Serial cranial computerized tomography scans revealed an expanding hypodense lesion in the parafalcine region consistent with SSST or a parasagittal abscess. Inadvertent left parietal limited craniectomy confirmed SSST. She recovered completely with subsequent conservative management. Beyond neuropsychiatric complications of Typhoid fever, CSVT should be highly considered when focal neurologic deficits are present. PMID:23227403

  1. Removal of Deeply Impacted Mandibular Molars by Sagittal Split Osteotomy

    PubMed Central

    Isler, Sabri Cemil

    2016-01-01

    Mandibular third molars are the most common impacted teeth. Mandibular first and second molars do not share the same frequency of occurrence. In rare cases the occlusal surfaces of impacted molars are united by the same follicular space and the roots pointing in opposite direction; these are called kissing molars. In some cases, a supernumerary fourth molar can be seen as unerupted and, in this case, such a supernumerary, deeply impacted fourth molar is seen neighboring kissing molars. The extraction of deeply impacted wisdom molars from the mandible may necessitate excessive bone removal and it causes complications such as damage to the inferior alveolar nerve and iatrogenic fractures of the mandible. This case report describes the use of the sagittal split osteotomy technique to avoid extensive bone removal and protect the inferior alveolar nerve during surgical extruction of multiple impacted teeth. PMID:27429810

  2. CORONAL FOURIER POWER SPECTRA: IMPLICATIONS FOR CORONAL SEISMOLOGY AND CORONAL HEATING

    SciTech Connect

    Ireland, J.; McAteer, R. T. J.; Inglis, A. R.

    2015-01-01

    The dynamics of regions of the solar corona are investigated using Atmospheric Imaging Assembly 171 Å and 193 Å data. The coronal emission from the quiet Sun, coronal loop footprints, coronal moss, and from above a sunspot is studied. It is shown that the mean Fourier power spectra in these regions can be described by a power law at lower frequencies that tails to a flat spectrum at higher frequencies, plus a Gaussian-shaped contribution that varies depending on the region studied. This Fourier spectral shape is in contrast to the commonly held assumption that coronal time series are well described by the sum of a long timescale background trend plus Gaussian-distributed noise, with some specific locations also showing an oscillatory signal. The implications of the observed spectral shape on the fields of coronal seismology and the automated detection of oscillations in the corona are discussed. The power-law contribution to the shape of the Fourier power spectrum is interpreted as being due to the summation of a distribution of exponentially decaying emission events along the line of sight. This is consistent with the idea that the solar atmosphere is heated everywhere by small energy deposition events.

  3. Head and brain response to blast using sagittal and transverse finite element models.

    PubMed

    Singh, Dilaver; Cronin, Duane S; Haladuick, Tyler N

    2014-04-01

    Mild traumatic brain injury caused by blast exposure from Improvised Explosive Devices has become increasingly prevalent in modern conflicts. To investigate head kinematics and brain tissue response in blast scenarios, two solid hexahedral blast-head models were developed in the sagittal and transverse planes. The models were coupled to an Arbitrary Lagrangian-Eulerian model of the surrounding air to model blast-head interaction, for three blast load cases (5 kg C4 at 3, 3.5 and 4 m). The models were validated using experimental kinematic data, where predicted accelerations were in good agreement with experimental tests, and intracranial pressure traces at four locations in the brain, where the models provided good predictions for frontal, temporal and parietal, but underpredicted pressures at the occipital location. Brain tissue response was investigated for the wide range of constitutive properties available. The models predicted relatively low peak principal brain tissue strains from 0.035 to 0.087; however, strain rates ranged from 225 to 571 s-1. Importantly, these models have allowed us to quantify expected strains and strain rates experienced in brain tissue, which can be used to guide future material characterization. These computationally efficient and predictive models can be used to evaluate protection and mitigation strategies in future analysis. PMID:24293124

  4. Heating Profiles of Coronal Loops

    NASA Astrophysics Data System (ADS)

    Plowman, Joseph; Kankelborg, Charles C.; Martens, Petrus C.

    2016-05-01

    We analyze the temperature and density profiles of coronal loops, as a function of their length, using data from SDO/AIA and Hinode/EIS. The analysis considers the location of the heating along the loop's length, and we conduct a more throrough investigation of our previous preliminary result that heating is concentrated near the loop footpoints. The work now features a larger selection of coronal loops, compared to our previous presentations, and examines their scale-height temperatures to ascertain the extent to which they are hydrostatic.

  5. Coronal Metallicities of Active Binaries

    NASA Astrophysics Data System (ADS)

    Kashyap, V.; Drake, J. J.; Pease, D. O.; Schmitt, J. H. M. M.

    1998-09-01

    We analyze EUV and X-ray data on a sample of X-ray active binary stars to determine coronal abundances. EUVE spectrometer data are used to obtain line fluxes, which are then used to determine Differential Emission Measures (DEMs). The continuum emission predicted for these DEMs (constrained at high temperatures by measurements in the X-ray regime where available) are then compared with EUVE/DS counts to derive coronal metallicities. These measurements indicate whether the coronae on these stars are metal deficient (the ``MAD Syndrome'') or subject to the FIP-effect (low First Ionization Potential elements have enhanced abundances relative to the photospheres).

  6. Solar wind flow upstream of the coronal slow shock

    NASA Technical Reports Server (NTRS)

    Whang, Y. C.

    1986-01-01

    Slow shocks have been predicted to exist embedded in large coronal holes at low altitude. Two or more curved slow shocks may link together to form a composite discontinuity surface around the sun which may be called the coronal slow shock (CSS). Here a solar-wind model is studied under the assumption that a standing CSS exists and cororates with the sun at a constant angular velocity. A steady, axisymmetrical one-fluid model is introduced to study the expansion of solar wind in the open-field region upstream of the CSS. The model requires that the conditions downstream of the CSS near the equatorial plane can produce a solar wind agreeable with the observations made near the earth's orbit. The paper presents an illustrative calculation in which the polar caps within 60 deg of the polar angle are assumed to be the source region of the solar wind.

  7. Modeling of transient disturbances in coronal-streamer configurations

    NASA Technical Reports Server (NTRS)

    Steinolfson, R. S.

    1983-01-01

    Numerical simulations of the formation and propagation of mass ejection, loop transients in coronal streamers are discussed. The simulations are accomplished with numerical solutions of the single fluid, ideal MHD equations of motion in the meridional plane. The streamer is produced by simulating the relaxation of an initially radial hydrodynamic flow coupled with a dipole magnetic field. The simulated transient then results from an energy release at the base of the streamer. The legs of the loop transient produced remain essentially stationary while the loop expands mainly in the radial direction with velocities of 400 to 750 km s-1. Once the leading edge of the transient has passed out of the lower corona, the initial streamer configuration is restored after 15 to 24 hours. A second energy release 2 hours later than, and with an energy release identical to, the first does not produce a significant coronal disturbance.

  8. Three-dimensional reconstruction of coronal mass ejections

    NASA Technical Reports Server (NTRS)

    Jackson, Bernard V.; Hick, Paul

    1994-01-01

    Computer assisted tomography (CAT) techniques are used to reconstruct the three dimensional shape of coronal mass ejections in the interplanetary medium. Both the Helios 2 spacecraft zodiacal-light photometers and the Solwind coronograph measure changes in Thomson scattering of sunlight from electrons. The technique from near-perpendicular Solwind and Helios views are applied to determine the density of a mass ejection which left the solar surface on 24 May 1979. The coronograph and the Helios perspective views are not simultaneous; the Solwind observations extend outward to sky plane distances of only 10 of the solar radius, whereas the Helios 16 photometer observes to as close as 17 of the solar radius from the sun. The solution is obtained by assuming outward radial expansion and that the coronal mass ejections (CME's) have the same speed everywhere at the same height. The analyses show that CME's are extensive three dimensional structures (the CME of 24 May appears approximately shell) like in three dimensions.

  9. The dependence of coronal hole size on large scale magnetic field strength. [using a mathematical model of the photosphere

    NASA Technical Reports Server (NTRS)

    Suess, S. T.; Steinolfson, R. S.

    1980-01-01

    The importance of mathematical models of the coronal structure for studies of coronal energetics, to simulate global flows of the solar wind, and to obtain reliable solar terrestrial predictions is discussed. Previous coronal models, including an example of a coronal MHD flow model, are reviewed. The development of a coronal model which is a logical extension of earlier models and which allows a closer relationship to the photospheric magnetic field as it is observed daily is described. The calculations are outlined. The assumptions of the model are: axisymmetric flow with no rotation, resulting in two dimensional flow in a meridional plane; zero viscosity and infinite electrical conductivity; polytropic, single fluid flow; and no momentum addition.

  10. CORONAL EMISSION LINES AS THERMOMETERS

    SciTech Connect

    Judge, Philip G.

    2010-01-10

    Coronal emission-line intensities are commonly used to measure electron temperatures using emission measure and/or line ratio methods. In the presence of systematic errors in atomic excitation calculations and data noise, the information on underlying temperature distributions is fundamentally limited. Increasing the number of emission lines used does not necessarily improve the ability to discriminate between different kinds of temperature distributions.

  11. An equatorial coronal hole at solar minimum

    NASA Technical Reports Server (NTRS)

    Bromage, B. J. I.; DelZanna, G.; DeForest, C.; Thompson, B.; Clegg, J. R.

    1997-01-01

    The large transequatorial coronal hole that was observed in the solar corona at the end of August 1996 is presented. It consists of a north polar coronal hole called the 'elephant's trunk or tusk'. The observations of this coronal hole were carried out with the coronal diagnostic spectrometer onboard the Solar and Heliospheric Observatory (SOHO). The magnetic field associated with the equatorial coronal hole is strongly connected to that of the active region at its base, resulting in the two features rotating at almost the same rate.

  12. Mid-callosal plane determination using preferred directions from diffusion tensor images

    NASA Astrophysics Data System (ADS)

    Costa, André L.; Rittner, Letícia; Lotufo, Roberto A.; Appenzeller, Simone

    2015-03-01

    The corpus callosum is the major brain structure responsible for inter{hemispheric communication between neurons. Many studies seek to relate corpus callosum attributes to patient characteristics, cerebral diseases and psychological disorders. Most of those studies rely on 2D analysis of the corpus callosum in the mid-sagittal plane. However, it is common to find conflicting results among studies, once many ignore methodological issues and define the mid-sagittal plane based on precary or invalid criteria with respect to the corpus callosum. In this work we propose a novel method to determine the mid-callosal plane using the corpus callosum internal preferred diffusion directions obtained from diffusion tensor images. This plane is analogous to the mid-sagittal plane, but intended to serve exclusively as the corpus callosum reference. Our method elucidates the great potential the directional information of the corpus callosum fibers have to indicate its own referential. Results from experiments with five image pairs from distinct subjects, obtained under the same conditions, demonstrate the method effectiveness to find the corpus callosum symmetric axis relative to the axial plane.

  13. Coronal Seismology: The Search for Propagating Waves in Coronal Loops

    NASA Astrophysics Data System (ADS)

    Schad, Thomas A.; Seeley, D.; Keil, S. L.; Tomczyk, S.

    2007-05-01

    We report on Doppler observations of the solar corona obtained in the Fe XeXIII 1074.7nm coronal emission line with the HAO Coronal Multi-Channel Polarimeter (CoMP) mounted on the NSO Coronal One Shot coronagraph located in the Hilltop Facility of NSO/Sacramento Peak. The COMP is a tunable filtergraph instrument that records the entire corona from the edge of the occulting disk at approximately 1.03 Rsun out to 1.4 Rsun with a spatial resolution of about 4” x 4”. COMP can be rapidly scanned through the spectral line while recording orthogonal states of linear and circular polarization. The two dimensional spatial resolution allows us to correlate temporal fluctuations observed in one part of the corona with those seen at other locations, in particular along coronal loops. Using cross spectral analysis we find that the observations reveal upward propagating waves that are characterized by Doppler shifts with rms velocities of 0.3 km/s, peak wave power in the 3-5 mHz frequency range, and phase speeds 1-3 Mm/s. The wave trajectories are consistent with the direction of the magnetic field inferred from the linear polarization measurements. We discuss the phase and coherence of these waves as a function of height in the corona and relate our findings to previous observations. The observed waves appear to be Alfvenic in character. "Thomas Schad was supported through the National Solar Observatory Research Experiences for Undergraduate (REU) site program, which is co-funded by the Department of Defense in partnership with the National Science Foundation REU Program." Daniel Seeley was supported through the National Solar Observatory Research Experience for Teachers (RET) site program, which is funded by the National Science Foundation RET program.

  14. New insights into the relationship between suture closure and craniofacial dysmorphology in sagittal nonsyndromic craniosynostosis

    PubMed Central

    Heuzé, Yann; Boyadjiev, Simeon A; Marsh, Jeffrey L; Kane, Alex A; Cherkez, Elijah; Boggan, James E; Richtsmeier, Joan T

    2010-01-01

    Premature closure of the sagittal suture occurs as an isolated (nonsyndromic) birth defect or as a syndromic anomaly in combination with other congenital dysmorphologies. The genetic causes of sagittal nonsyndromic craniosynostosis (NSC) remain unknown. Although variation of the dysmorphic (scaphocephaly) skull shape of sagittal NSC cases has been acknowledged, this variation has not been quantitatively studied three-dimensionally (3D). We have analyzed the computed tomography skull images of 43 infants (aged 0.9–9 months) with sagittal NSC using anatomical landmarks and semilandmarks to quantify and characterize the within-sample phenotypic variation. Suture closure patterns were defined by dividing the sagittal suture into three sections (anterior, central, posterior) and coding each section as ‘closed’ or ‘fused’. Principal components analysis of the Procrustes shape coordinates representing the skull shape of 43 cases of NSC did not separate individuals by sex, chronological age, or dental stages of the deciduous maxillary first molar. However, analysis of suture closure pattern allowed separation of these data. The central section of the sagittal suture appears to be the first to fuse. Then, at least two different developmental paths towards complete fusion of the sagittal suture exist; either the anterior section or the posterior section is the second to fuse. Results indicate that according to the sequence of sagittal suture closure patterns, different craniofacial complex shapes are observed. The relationship between craniofacial shape and suture closure indicates not only which suture fused prematurely (in our case the sagittal suture), but also the pattern of the suture closure. Whether these patterns indicate differences in etiology cannot be determined with our data and requires analysis of longitudinal data, most appropriately of animal models where prenatal conditions can be monitored. PMID:20572900

  15. Super-resolution reconstruction in frequency, image, and wavelet domains to reduce through-plane partial voluming in MRI

    SciTech Connect

    Gholipour, Ali Afacan, Onur; Scherrer, Benoit; Prabhu, Sanjay P.; Warfield, Simon K.; Aganj, Iman; Sahin, Mustafa

    2015-12-15

    Purpose: To compare and evaluate the use of super-resolution reconstruction (SRR), in frequency, image, and wavelet domains, to reduce through-plane partial voluming effects in magnetic resonance imaging. Methods: The reconstruction of an isotropic high-resolution image from multiple thick-slice scans has been investigated through techniques in frequency, image, and wavelet domains. Experiments were carried out with thick-slice T2-weighted fast spin echo sequence on the Academic College of Radiology MRI phantom, where the reconstructed images were compared to a reference high-resolution scan using peak signal-to-noise ratio (PSNR), structural similarity image metric (SSIM), mutual information (MI), and the mean absolute error (MAE) of image intensity profiles. The application of super-resolution reconstruction was then examined in retrospective processing of clinical neuroimages of ten pediatric patients with tuberous sclerosis complex (TSC) to reduce through-plane partial voluming for improved 3D delineation and visualization of thin radial bands of white matter abnormalities. Results: Quantitative evaluation results show improvements in all evaluation metrics through super-resolution reconstruction in the frequency, image, and wavelet domains, with the highest values obtained from SRR in the image domain. The metric values for image-domain SRR versus the original axial, coronal, and sagittal images were PSNR = 32.26 vs 32.22, 32.16, 30.65; SSIM = 0.931 vs 0.922, 0.924, 0.918; MI = 0.871 vs 0.842, 0.844, 0.831; and MAE = 5.38 vs 7.34, 7.06, 6.19. All similarity metrics showed high correlations with expert ranking of image resolution with MI showing the highest correlation at 0.943. Qualitative assessment of the neuroimages of ten TSC patients through in-plane and out-of-plane visualization of structures showed the extent of partial voluming effect in a real clinical scenario and its reduction using SRR. Blinded expert evaluation of image resolution in

  16. POST-CORONAL MASS EJECTION PLASMA OBSERVED BY HINODE

    SciTech Connect

    Landi, E.; Raymond, J. C.; Miralles, M. P.; Hara, H.

    2012-05-20

    In the present work we study the evolution of an active region after the eruption of a coronal mass ejection (CME) using observations from the EIS and XRT instruments on board Hinode. The field of view includes a post-eruption arcade, a current sheet, and a coronal dimming. The goal of this paper is to provide a comprehensive set of measurements for all these aspects of the CME phenomenon made on the same CME event. The main physical properties of the plasma along the line of sight-electron density, thermal structure, plasma composition, size, and, when possible, mass-are measured and monitored with time for the first three hours following the CME event of 2008 April 9. We find that the loop arcade observed by EIS and XRT may not be related to the post-eruption arcade. Post-CME plasma is hotter than the surrounding corona, but its temperature never exceeds 3 MK. Both the electron density and thermal structure do not show significant evolution with time, while we found that the size of the loop arcade in the Hinode plane of the sky decreased with time. The plasma composition is the same in the current sheet, in the loop arcade, and in the ambient plasma, so all these plasmas are likely of coronal origin. No significant plasma flows were detected.

  17. Identification of IGF-I in the calvarial suture of young rats: histochemical analysis of the cranial sagittal sutures in a hyperthyroid rat model.

    PubMed

    Akita, S; Hirano, A; Fujii, T

    1996-01-01

    staining of IGF-I was markedly increased in the suture margins of the T3-treated group. There were no significant differences observed either in the skull base measurements or in the histologic and histochemical findings of the skull base or the coronal suture between the groups. More significantly, excess administration of thyroid hormone enhanced the cranial sagittal suture closure; therefore, it was proposed that local IGF-I plays an important role in sagittal sutural bone formation. PMID:8532765

  18. HEATCVB: Coronal heating rate approximations

    NASA Astrophysics Data System (ADS)

    Cranmer, Steven R.

    2015-06-01

    HEATCVB is a stand-alone Fortran 77 subroutine that estimates the local volumetric coronal heating rate with four required inputs: the radial distance r, the wind speed u, the mass density ρ, and the magnetic field strength |B0|. The primary output is the heating rate Qturb at the location defined by the input parameters. HEATCVB also computes the local turbulent dissipation rate of the waves, γ = Qturb/(2UA).

  19. The Coronal Loop Inventory Project

    NASA Astrophysics Data System (ADS)

    Schmelz, J. T.; Pathak, S.; Christian, G. M.; Dhaliwal, R. S. S.; Paul, K. S.

    2015-11-01

    Most coronal physicists now seem to agree that loops are composed of tangled magnetic strands and have both isothermal and multithermal cross-field temperature distributions. As yet, however, there is no information on the relative importance of each of these categories, and we do not know how common one is with respect to the other. In this paper, we investigate these temperature properties for all loop segments visible in the 171-Å image of AR 11294, which was observed by the Atmospheric Imaging Assembly (AIA) on 2011 September 15. Our analysis revealed 19 loop segments, but only 2 of these were clearly isothermal. Six additional segments were effectively isothermal, that is, the plasma emission to which AIA is sensitive could not be distinguished from isothermal emission, within measurement uncertainties. One loop had both isothermal transition region and multithermal coronal solutions. Another five loop segments require multithermal plasma to reproduce the AIA observations. The five remaining loop segments could not be separated reliably from the background in the crucial non-171-Å AIA images required for temperature analysis. We hope that the direction of coronal heating models and the efforts modelers spend on various heating scenarios will be influenced by these results.

  20. Impulsively generated fast coronal pulsations

    NASA Technical Reports Server (NTRS)

    Edwin, P. M.; Roberts, B.

    1986-01-01

    Rapid oscillations in the corona are discussed from a theoretical standpoint, developing some previous work on ducted, fast magnetoacoustic waves in an inhomogeneous medium. In the theory, impulsively (e.g., flare) generated mhd (magnetohydrodynamic) waves are ducted by regions of low Alfven speed (high density) such as coronal loops. Wave propagation in such ducts is strongly dispersive and closely akin to the behavior of Love waves in seismology, Pekeris waves in oceanography and guided waves in fiber optics. Such flare-generated magnetoacoustic waves possess distinctive temporal signatures consisting of periodic, quasi-periodic and decay phases. The quasi-periodic phase possesses the strongest amplitudes and the shortest time scales. Time scales are typically of the order of a second for inhomogeneities (coronal loop width) of 1000 km and Alfven speeds of 1000/kms, and pulse duration times are of tens of seconds. Quasi-periodic signatures have been observed in radio wavelengths for over a decade and more recently by SMM. It is hoped that the theoretical ideas outlined may be successfully related to these observations and thus aid the interpretation of oscillatory signatures recorded by SMM. Such signatures may also provide a diagnostic of coronal conditions. New aspects of the ducted mhd waves, for example their behavior in smoothly varying as opposed to tube-like inhomogeneities, are currently under investigation. The theory is not restricted to loops but applied equally to open field regions.

  1. The Structure of Coronal Loops

    NASA Technical Reports Server (NTRS)

    Antiochos, Spiro K.

    2009-01-01

    It is widely believed that the simple coronal loops observed by XUV imagers, such as EIT, TRACE, or XRT, actually have a complex internal structure consisting of many (perhaps hundreds) of unresolved, interwoven "strands". According to the nanoflare model, photospheric motions tangle the strands, causing them to reconnect and release the energy required to produce the observed loop plasma. Although the strands, themselves, are unresolved by present-generation imagers, there is compelling evidence for their existence and for the nanoflare model from analysis of loop intensities and temporal evolution. A problem with this scenario is that, although reconnection can eliminate some of the strand tangles, it cannot destroy helicity, which should eventually build up to observable scales. we consider, therefore, the injection and evolution of helicity by the nanoflare process and its implications for the observed structure of loops and the large-scale corona. we argue that helicity does survive and build up to observable levels, but on spatial and temporal scales larger than those of coronal loops. we discuss the implications of these results for coronal loops and the corona, in general .

  2. On the nature of transverse coronal waves revealed by wavefront dislocations

    NASA Astrophysics Data System (ADS)

    López Ariste, A.; Luna, M.; Arregui, I.; Khomenko, E.; Collados, M.

    2015-07-01

    Context. Coronal waves are an important aspect of the dynamics of the plasma in the corona. Wavefront dislocations are topological features of most waves in nature and also of magnetohydrodynamic waves. Are there dislocations in coronal waves? Aims: The finding and explanation of dislocations may shed light on the nature and characteristics of the propagating waves, their interaction in the corona, and in general on the plasma dynamics. Methods: We positively identify dislocations in coronal waves observed by the Coronal Multi-channel Polarimeter (CoMP) as singularities in the Doppler shifts of emission coronal lines. We study the possible singularities that can be expected in coronal waves and try to reproduce the observed dislocations in terms of localization and frequency of appearance. Results: The observed dislocations can only be explained by the interference of a kink and sausage wave modes propagating with different frequencies along the coronal magnetic field. In the plane transverse to the propagation, the cross-section of the oscillating plasma must be smaller than the spatial resolution, and the two waves result in net longitudinal and transverse velocity components that are mixed through projection onto the line of sight. Alfvén waves can be responsible for the kink mode, but a magnetoacoustic sausage mode is necessary in all cases. Higher (flute) modes are excluded. The kink mode has a pressure amplitude that is less than the pressure amplitude of the sausage mode, though its observed velocity is higher. This concentrates dislocations on the top of the loop. Conclusions: To explain dislocations, any model of coronal waves must include the simultaneous propagation and interference of kink and sausage wave modes of comparable but different frequencies with a sausage wave amplitude much smaller than the kink one. Appendix A is available in electronic form at http://www.aanda.org

  3. An unusual, possibly "new" MA/MR syndrome with sagittal craniosynostosis.

    PubMed

    Pfeiffer, R A; Tietze, U; Welte, W

    1987-01-01

    This report is on a mentally retarded, male child with multiple anomalies: sagittal craniostenosis, bilateral coloboma of the iris, craniofacial dysmorphy, asymmetrical split hand malformation, bilateral syndactyly of 2nd-4th toes and perineoscrotal hypospadias. PMID:3034618

  4. Skeletal Stability after Bilateral Sagittal Split Advancement and Setback Osteotomy of the Mandible with Miniplate Fixation

    PubMed Central

    Rao, Srinivasan Hanumantha; Selvaraj, Loganathan; Lankupalli, Arathy S.

    2013-01-01

    The purpose of this study was to evaluate intraorally placed mini plates and monocortical screws in terms of postoperative skeletal stability after bilateral sagittal split advancement and setback osteotomy of the mandible. Ten patients were included in this study with five requiring advancement (group I) and five requiring setback of the mandible (group II). Bell and Epker modified surgical technique was followed for all the patients. All the patients underwent pre- and postsurgical orthodontics. Cephalometric radiographs were taken preoperatively, immediate, 3, 6, and 12 months postoperatively. Cephalometric tracings were performed by one individual examiner using a modified burstone analysis. Statistical analysis was performed using the student paired t-test. In advancement patients, SNB (sella, Nasion, B point) angle showed relapse at 12th month postoperative period which was statistically significant (2.4 degrees). No changes were observed in anterior facial height, posterior facial height, Frankfort-mandibular incisor angle (FmiA), and overjet during the follow-up period. In setback patients, posterior facial height (p < 0.05), angles between the lower incisors and mandibular plane and pogonion had a statistically significant change position of 1.4 mm (paired t-test, p = 0.03). The SNB angle, anterior facial height, interincisal angle, and FmiA remained constant (0.8–1.2 degrees) during the follow-up period. In advancement cases, the relapse was seen from the third month postoperative period but in setback cases, the relapse was noted from the sixth month onward and the skeletal relapse in these cases were noticed cephalometrically. PMID:24624252

  5. Errors in measuring sagittal arch kinematics of the human foot with digital fluoroscopy.

    PubMed

    Wearing, Scott C; Smeathers, James E; Yates, Bede; Sullivan, Patrick M; Urry, Stephen R; Dubois, Philip

    2005-04-01

    Although fluoroscopy has been used to evaluate motion of the foot during gait, the accuracy and precision of fluoroscopic measures of osseous structures of the foot has not been reported in the literature. This study reports on a series of experiments that quantify the magnitude and sources of error involved in digital fluoroscopic measurements of the medial longitudinal arch. The findings indicate that with a global distortion correction procedure, errors arising from image distortion can be reduced threefold to 0.2 degrees for angular measurements and to 0.1 mm for linear measures. The limits of agreement for repeated angular measures of the calcaneus and first metatarsal were +/-0.5 degrees and +/-0.6 degrees , indicating that measurement error was primarily associated with the manual process of digitisation. While the magnitude of the residual error constitutes about +/-2.5% of the expected 20 degrees of movement of the calcaneus and first metatarsal, out-of-plane rotation may potentially contribute the greatest source of error in fluoroscopic measures of the foot. However, even at the extremes of angular displacement (15 degrees ) reported for the calcaneum during running gait, the root mean square (RMS) error was only about 1 degrees . Thus, errors associated with fluoroscopic imaging of the foot appear to be negligible when compared to those arising from skin movement artefact, which typically range between 1.5 and 4 mm (equating to errors of 2 degrees to 17 degrees for angular measures). Fluoroscopy, therefore, may be a useful technique for analysing the sagittal movement of the medial longitudinal arch during the contact phase of walking. PMID:15760749

  6. Coronal abundances determined from energetic particles

    NASA Technical Reports Server (NTRS)

    Reames, D. V.

    1995-01-01

    Solar energetic particles (SEPs) provide a measurement of coronal element abundances that is highly independent of the ionization states and temperature of the ions in the source plasma. The most complete measurements come from large 'gradual' events where ambient coronal plasma is swept up by the expanding shock wave from a coronal mass ejection. Particles from 'impulsive' flares have a pattern of acceleration-induced enhancements superimposed on the coronal abundances. Particles accelerated from high-speed solar wind streams at corotating shocks show a different abundance pattern corresponding to material from coronal holes. Large variations in He/O in coronal material are seen for both gradual and impulsive-flare events but other abundance ratios, such as Mg/Ne, are remarkably constant. SEP measurements now include hundreds of events spanning 15 years of high-quality measurement.

  7. EUV Coronal Dimming and its Relationship to Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Mason, James

    2016-05-01

    As a coronal mass ejection (CME) departs from the inner solar atmosphere, it leaves behind a void. This region of depleted plasma results in a corresponding decrease in coronal emissions that can be observed by instruments tuned to measure the extreme ultraviolet (EUV) part of the electromagnetic spectrum. These coronal dimmings can be observed with EUV imagers and EUV spectral irradiance instruments. Onboard the Solar Dynamics Observatory (SDO), the EUV Variability Experiment (EVE) and Atmospheric Imaging Assembly (AIA) provide complementary observations; together they can be used to obtain high spatial and spectral resolution. AIA provides information about the location, extent, and spatial evolution of the dimming while EVE data are important to understand plasma temperature evolution. Concurrent processes with similar timescales to mass-loss dimming also impact the observations, which makes a deconvolution method necessary for the irradiance time series in order to have a “clean” mass-loss dimming light curve that can be parameterized and compared with CME kinematics. This presentation will first provide background on these various physical processes and the deconvolution method developed. Two case studies will then be presented, followed by a semi-statistical study (~30 events) to establish a correlation between dimming and CME parameters. In particular, the slope of the deconvolved irradiance dimming light curve is representative of the CME speed, and the irradiance dimming depth can serve as a proxy for CME mass. Finally, plans and early results from a more complete statistical study of all dimmings in the SDO era, based on an automated detection routine using EVE data, will be described and compared with independently derived dimmings automatically detected with AIA data.

  8. The relationship between coronal streamers and CMEs.

    NASA Astrophysics Data System (ADS)

    Du, Jinsheng; Tong, Yi; Yang, Jing; Eselevich, V. G.

    1999-06-01

    The variation of the polarization brightness of coronal streamer in Carrington Rotations 1591 - 1592 is investigated. The distribution of the polarization brightness along streamer belts is inhomogeneous; the degree of the inhomogeneity is 10% - 50%. In the absence of coronal mass ejection (CME) influence, the distribution of coronal streamers along the streamer belts can persist stable during nearly two Carrington Rotations. The rise velocity of the top of the cusp region in a coronal streamer may be more than 2 km/s, if the longitude angular size is more than 27° associated with a CME occurrence.

  9. On Recurrent/Homologous Coronal Jets Emission: Coronal Geyser Structures

    NASA Astrophysics Data System (ADS)

    Razvan Paraschiv, Alin; Donea, Alina

    2016-05-01

    Active region 11302 has shown a vast display of solar jets during its lifetime. We examine the emission mechanism responsible for multiple coronal jet events occurring at the center-east side of the active region. Identified jet events were detected in extreme-ultraviolet (EUV), hard X-ray (HXR) and radio emissions, observed by dedicated instruments such as SDO's AIA and HMI, STEREO's EUVI and WAVES, and RHESSI, respectively. We report the detection of a base-arch structure in the lower atmosphere. The site was labelled "Coronal Geyser". The structure had emitted jets quasi-periodically for the entire time the AR was visible in SDO'S field of view. The jets expand into the corona with an apparent line of sight velocity of ~200-300$ km/s. To our knowledge the long time-scale behaviour of jet recurrence and base geyser structure was not previously discussed and data analysis of this phenomena will provide new information for theoretical modelling and data interpretation of jets.

  10. THE RELATIONSHIP BETWEEN CORONAL DIMMING AND CORONAL MASS EJECTION PROPERTIES

    SciTech Connect

    Reinard, A. A.

    2009-11-01

    Coronal dimmings are closely related to the footpoints of coronal mass ejections (CMEs) and, as such, offer information about CME origins and evolution. In this paper, we investigate the relationship between CME and dimming properties. In particular, we compare CME quantities for events with and without associated dimmings. We find that dimming-associated CMEs, on average, have much higher speeds than non-dimming-associated events. In fact, CMEs without an associated dimming do not appear to travel faster than 800 km s{sup -1}, i.e., the fast solar wind speed. Dimming-associated events are also more likely to be associated with flares, and those flares tend to have the highest magnitudes. We propose that each of these phenomena is affected by the energy available in the source region. Highly energetic source regions produce fast CMEs that are accompanied by larger flares and visible dimmings, while less energetic source regions produce slow CMEs that are accompanied by smaller flares and may or may not have dimmings. The production of dimmings in the latter case may depend on a number of factors including initiation height of the CME, source region magnetic configuration, and observational effects. These results have important implications for understanding and predicting CME initiations.

  11. Photospheric and coronal magnetic fields

    SciTech Connect

    Sheeley, N.R., Jr. )

    1991-01-01

    Research on small-scale and large-scale photospheric and coronal magnetic fields during 1987-1990 is reviewed, focusing on observational studies. Particular attention is given to the new techniques, which include the correlation tracking of granules, the use of highly Zeeman-sensitive infrared spectral lines and multiple lines to deduce small-scale field strength, the application of long integration times coupled with good seeing conditions to study weak fields, and the use of high-resolution CCD detectors together with computer image-processing techniques to obtain images with unsurpassed spatial resolution. Synoptic observations of large-scale fields during the sunspot cycle are also discussed. 101 refs.

  12. Fishing in the Coronal Graveyard

    NASA Astrophysics Data System (ADS)

    Ayres, T. R.; Brown, A.; Harper, G. M.; Bennett, P. D.; Linsky, J. L.; Carpenter, K. G.; Robinson, R. D.

    1996-12-01

    Hot coronae (T ~ 10(6) K) are thought to be rare among single giant stars to the right of the ``Linsky--Haisch dividing line'' near K0 in the H--R diagram. K and M giants are such slow rotators that absence of dynamo generated magnetic activity would be natural. Nevertheless, gamma Dra (K5 III) unexpectedly was detected in FUV coronal proxies---hot lines Si IV lambda 1393 and C IV lambda 1548---by HST /GHRS during Science Verification, and subsequently was discovered as a faint X-ray source in a deep ROSAT /PSPC pointing. Is gamma Dra anomalous, or is the lack of coronal detections among the K giants simply a matter of insufficient sensitivity? We have used the GHRS low resolution mode to search for additional examples of hot lines among inactive single red giants. Si IV provides a clean diagnostic of subcoronal material because it falls near the peak sensitivity of the G140L mode and does not suffer from abundance depletions that can affect C IV in red giants. X-ray/Si IV ratios are such that HST can reach to much fainter limiting ``coronal'' magnitudes than even very deep ROSAT pointings. In every target so far examined, we find weak---but statistically significant---Si IV emission. These include: the ancient red giant Arcturus (alpha Boo: K1 III), recorded at the end of Cycle 5; and epsilon Crv (K2.5 III) and epsilon Sco (K2 III) observed in Cycle 6. X-ray/Si IV ratios of red giants (for which measurements, or upper limits, of both diagnostics are available) fall on a uniform track, extending downward from active K0 ``Clump'' giants like beta Ceti all the way to Arcturus itself, in the depths of the ``coronal graveyard.'' The systematic behavior argues that magnetic dynamo action continues even when long term angular momentum loss has slowed the stellar spin to a crawl. This work was supported by grant GO-06066.01-94A from STScI.

  13. Correlations of Cervical Sagittal Alignment before and after Occipitocervical Fusion.

    PubMed

    Matsubayashi, Yoshitaka; Shimizu, Takachika; Chikuda, Hirotaka; Takeshita, Katsushi; Oshima, Yasushi; Tanaka, Sakae

    2016-06-01

    Study Design Retrospective radiographic study. Objective To investigate changes and correlations of cervical sagittal alignment including T1 slope before and after occipitocervical corrective surgery. We also investigated the relevance for preoperative planning. Methods We conducted a retrospective radiographic analysis of 27 patients who underwent surgery for occipitocervical deformity. There were 7 men and 20 women with a mean age of 56.0 years. Mean follow-up was 68.0 months (range 24 to 120). The radiographic parameters measured before surgery and at final follow-up included McGregor slope, T1 slope, occipito (O)-C2 angle, O-C7 angle, and C2-C7 angle. Pearson correlation coefficient was used to examine the correlation between the radiographic parameters. Results There was a stronger positive correlation between the T1 slope and the O-C7 angle both preoperatively and postoperatively (r = 0.72 and r = 0.83, respectively) than between the T1 slope and the C2-C7 angle (r = 0.60 and r = 0.76, respectively). The O-C2 angle and C2-C7 angle had inverse correlations to each other both pre- and postoperatively (r =  - 0.50 and -0.45). McGregor slope and T1 slope did not significantly change postoperatively at final follow-up. Increase in O-C2 angle after surgery (mean change, 10.7 degrees) inversely correlated with decrease in postoperative C2-C7 angle (mean change, 12.2 degrees). As result of these complementary changes, O-C7 angle did not statistically change. Conclusions Our results suggest that the O-C7 angle is regulated by T1 slope and the corresponding O-C7 angle is divided into the O-C2 and C2-C7 angles, which have inverse correlation to each other and then maintain McGregor slope (horizontal gaze). PMID:27190739

  14. Normalization of brain morphology after surgery in sagittal craniosynostosis.

    PubMed

    Brooks, Eric D; Yang, Jenny; Beckett, Joel S; Lacadie, Cheryl; Scheinost, Dustin; Persing, Sarah; Zellner, Elizabeth G; Oosting, Devon; Keifer, Cara; Friedman, Hannah E; Wyk, Brent Vander; Jou, Roger J; Sun, Haosi; Gary, Cyril; Duncan, Charles C; Constable, R Todd; Pelphrey, Kevin A; Persing, John A

    2016-04-01

    OBJECT Nonsyndromic craniosynostosis (NSC) is associated with significant learning disability later in life. Surgical reconstruction is typically performed before 1 year of age to correct the cranial vault morphology and to allow for normalized brain growth with the goal of improving cognitive function. Yet, no studies have assessed to what extent normalized brain growth is actually achieved. Recent advances in MRI have allowed for automated methods of objectively assessing subtle and pronounced brain morphological differences. The authors used one such technique, deformation-based morphometry (DBM) Jacobian mapping, to determine how previously treated adolescents with sagittal NSC (sNSC) significantly differ in brain anatomy compared with healthy matched controls up to 11.5 years after surgery. METHODS Eight adolescent patients with sNSC, previously treated via whole-vault cranioplasty at a mean age of 7 months, and 8 age- and IQ-matched control subjects without craniosynostosis (mean age for both groups = 12.3 years), underwent functional 3-T MRI. Statistically significant group tissue-volume differences were assessed using DBM, a whole-brain technique that estimates morphological differences between 2 groups at each voxel (p < 0.01). Group-wise Jacobian volume maps were generated using a spacing of 1.5 mm and a resolution of 1.05 × 1.05 × 1.05 mm(3). RESULTS There were no significant areas of volume reduction or expansion in any brain areas in adolescents with sNSC compared with controls at a significance level of p < 0.01. At the more liberal threshold of p < 0.05, two areas of brain expansion extending anteroposteriorly in the right temporooccipital and left frontoparietal regions appeared in patients with sNSC compared with controls. CONCLUSIONS Compared with previous reports on untreated infants with sNSC, adolescents with sNSC in this cohort had few areas of brain dysmorphology many years after surgery. This result suggests that comprehensive cranioplasty

  15. Anomalous transmission of a coronal "EIT wave" through a nearby coronal hole

    NASA Astrophysics Data System (ADS)

    Long, David; Perez-Suarez, David; Valori, Gherardo

    2016-05-01

    Observations of reflection at coronal hole boundaries and transmission through the coronal hole suggest that "EIT waves" may be interpreted as freely--propagating wave--pulses initially driven by the rapid expansion of a coronal mass ejection (CME) in the low corona. An "EIT wave" observed on 2012 July 07 is seen to impact an adjacent coronal hole. However, rather than reappearing at the far edge of the coronal hole as with previous observations, the "EIT wave" was subsequently observed to reappear ~360 Mm away in the quiet Sun. The non-typical evolution of the "EIT wave" is examined using a combination of observations of the eruption from SDO/AIA and STEREO-A/EUVI as well as extrapolations of the global magnetic field. The observed "jump" in position of the "EIT wave" is shown to be due to the wave pulse traveling along hot coronal loops connecting the edge of the coronal hole with the quiet Sun.

  16. Meterwave observations of a coronal hole

    NASA Technical Reports Server (NTRS)

    Wang, Z.; Schmahl, E. J.; Kundu, M. R.

    1987-01-01

    Meter-wave maps are presented showing a coronal hole at 30.9, 50.0, and 73.8 MHz using the Clark Lake Radioheliograph in October 1984. The coronal hole seen against the disk at all three frequencies shows interesting similarities to, and significant differences from its optical signatures in HeI lambda10830 spectroheliograms. The 73.8 MHz coronal hole, when seen near disk center, appears to coincide with the HeI footprint of the hole. At the lower frequencies, the emission comes from higher levels of the corona, and the hole appears to be displaced, probably due to the non-radial structure of the coronal hole. The contrast of the hole relative to the quiet Sun is much greater than reported previously for a coronal hole observed at 80 MHz. The higher contrast is certainly real, due to the superior dynamic range, sensitivity, and calibration of the Clark Lake instrument. Using a coronal hole model, the electron density is derived from radio observations of the brightness temperature. A very large discrepancy is found between the derived density and that determined from Skylab EUV observations of coronal holes. This discrepancy suggests that much of the physics of coronal holes has yet to be elucidated.

  17. The effects of age and gender on the lumbopelvic rhythm in the sagittal plane in 309 subjects.

    PubMed

    Pries, Esther; Dreischarf, Marcel; Bashkuev, Maxim; Putzier, Michael; Schmidt, Hendrik

    2015-09-18

    Frequent upper body bending is associated with low back pain (LBP). The complex flexion movement, combining lumbar and pelvic motion, is known as "lumbopelvic rhythm" and can be quantified by dividing the change in the lumbar spine curvature by the change in pelvic orientation during flexion movement (L/P ratio). This parameter is clinically essential for LBP prevention, for diagnostic procedures and therapy; however, the effects of age and gender, in detail, are unknown. The Epionics SPINE system, utilizing strain-gauge technology and acceleration sensors, was used to assess lumbar lordosis and sacrum orientation during standing and lumbar angle and sacrum orientation during maximal upper body flexion in 309 asymptomatic subjects (age: 20-75 yrs; ♂: 134; ♀: 175). The effects of age and gender on these characteristics as well as on the resultant range of flexion (RoF) and lumbopelvic rhythm were investigated. Aging significantly reduced lumbar lordosis by 8.2° and sacrum orientation by 6.6° during standing in all subjects. With aging, the lumbar RoF decreased by 7.7°, whereas the pelvic RoF compensated for this effect and increased by 7.0°. The L/P ratio decreased from 0.80 to 0.65 with age; however, this decrease was only significant in men. Gender affected sacrum orientation in standing and in flexion as well as the L/P ratio. This study demonstrated the effects of age and gender on lordosis, sacrum orientation and lumbopelvic rhythm. These findings are of importance for the individual prevention of LBP, and provide a baseline for differentiating symptomatic from asymptomatic age- and gender-matched subjects. PMID:26294355

  18. Sagittal plane blockage of the foot, ankle and hallux and foot alignment-prevalence and association with low back pain

    PubMed Central

    Brantingham, James W.; Lee Gilbert, Joanne; Shaik, Junaid; Globe, Gary

    2006-01-01

    Abstract Introduction Some practitioners believe mechanical low back pain may be caused or aggravated by a stiff ankle, stiff great toe or flat feet. This study investigates subjects with and without mechanical low back pain and measures ankle and great toe range of motion and flattening of the medial longitudinal arch in both groups. Methods The study was a blinded, 2-arm, non- randomized clinical study involving 100 subjects with chronic or recurrent mechanical low back pain (intervention group) and 104 subjects without chronic mechanical low back pain (control group) between the ages of 18 and 45. A blind assessor performed weight-bearing goniometry of the ankle and big toe and the navicular drop test on all subjects in both groups. Results An independent t-test (inter-group) revealed a statistically significant decrease (p ≤ 0.05) in ankle dorsiflexion range of motion in individuals with chronic mechanical low back pain. The independent t-test suggested individuals with chronic mechanical low back pain have a significantly smaller navicular drop and higher arches (p < 0.05). Conclusion This study supports previous reports suggesting decreased ankle dorsiflexion may be a factor in chronic mechanical low-back pain. Further research and replication of this study is necessary before firm conclusions or recommendations can be made. PMID:19674683

  19. Rehabilitation after ACL Injury: A Fluoroscopic Study on the Effects of Type of Exercise on the Knee Sagittal Plane Arthrokinematics

    PubMed Central

    Norouzi, Sadegh; Esfandiarpour, Fateme; Shakourirad, Ali; Salehi, Reza; Akbar, Mohammad; Farahmand, Farzam

    2013-01-01

    A safe rehabilitation exercise for anterior cruciate ligament (ACL) injuries needs to be compatible with the normal knee arthrokinematics to avoid abnormal loading on the joint structures. The objective of this study was to measure the amount of the anterior tibial translation (ATT) of the ACL-deficient knees during selective open and closed kinetic chain exercises. The intact and injured knees of fourteen male subjects with unilateral ACL injury were imaged using uniplanar fluoroscopy, while the subjects performed forward lunge and unloaded/loaded open kinetic knee extension exercises. The ATTs were measured from fluoroscopic images, as the distance between the tibial and femoral reference points, at seven knee flexion angles, from 0° to 90°. No significant differences were found between the ATTs of the ACL-deficient and intact knees at all flexion angles during forward lunge and unloaded open kinetic knee extension (P < 0.05). During loaded open kinetic knee extension, however, the ATTs of the ACL deficient knees were significantly larger than those of the intact knees at 0° (P = 0.002) and 15° (P = 0.012). It was suggested that the forward lunge, as a weight-bearing closed kinetic chain exercise, provides a safer approach for developing muscle strength and functional stability in rehabilitation program of ACL-deficient knees, in comparison with open kinetic knee extension exercise. PMID:24066288

  20. Gender Differences among Sagittal Plane Knee Kinematic and Ground Reaction Force Characteristics during a Rapid Sprint and Cut Maneuver

    ERIC Educational Resources Information Center

    James, C. Roger; Sizer, Phillip S.; Starch, David W.; Lockhart, Thurmon E.; Slauterbeck, James

    2004-01-01

    Women are more prone to anterior cruciate ligament (ACL) injury during cutting sports than men. The purpose of this study was to examine knee kinematic and ground reaction forces (GRF) differences between genders during cutting. Male and female athletes performed cutting trials while force platform and video data were recorded (180 Hz).…

  1. Neuromuscular Fatigue Alters Postural Control and Sagittal Plane Hip Biomechanics in Active Females With Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Frank, Barnett S.; Gilsdorf, Christine M.; Goerger, Benjamin M.; Prentice, William E.; Padua, Darin A.

    2014-01-01

    Background: Females with history of anterior cruciate ligament (ACL) injury and subsequent ligament reconstruction are at high risk for future ACL injury. Fatigue may influence the increased risk of future injury in females by altering lower extremity biomechanics and postural control. Hypothesis: Fatigue will promote lower extremity biomechanics and postural control deficits associated with ACL injury. Study Design: Descriptive laboratory study. Methods: Fourteen physically active females with ACL reconstruction (mean age, 19.64 ± 1.5 years; mean height, 163.52 ± 6.18 cm; mean mass, 62.6 ± 13.97 kg) volunteered for this study. Postural control and lower extremity biomechanics were assessed in the surgical limb during single-leg balance and jump-landing tasks before and after a fatigue protocol. Main outcome measures were 3-dimensional hip and knee joint angles at initial contact, peak angles, joint angular displacements and peak net joint moments, anterior tibial shear force, and vertical ground reaction force during the first 50% of the loading phase of the jump-landing task. During the single-leg stance task, the main outcome measure was center of pressure sway speed. Results: Initial contact hip flexion angle decreased (t = −2.82, P = 0.01; prefatigue, 40.98° ± 9.79°; postfatigue, 36.75° ± 8.61°) from pre- to postfatigue. Hip flexion displacement (t = 2.23, P = 0.04; prefatigue, 45.19° ± 14.1°; postfatigue, 47.48° ± 14.21°) and center of pressure sway speed (t = 3.95, P < 0.05; prefatigue, 5.18 ± 0.96 cm/s; postfatigue, 6.20 ± 1.72 cm/s) increased from pre- to postfatigue. There was a trending increase in hip flexion moment (t = 2.14, P = 0.05; prefatigue, 1.66 ± 0.68 Nm/kg/m; postfatigue, 1.91 ± 0.62 Nm/kg/m) from pre- to postfatigue. Conclusion: Fatigue may induce lower extremity biomechanics and postural control deficits that may be associated with ACL injury in physically active females with ACL reconstruction. Clinical Relevance: Rehabilitation and maintenance programs should incorporate activities that aim to improve muscular endurance and improve the neuromuscular system’s tolerance to fatiguing exercise in efforts to maintain stability and safe landing technique during subsequent physical activity. PMID:24982701

  2. Spine Shape in Sagittal and Frontal Planes in Short- and Tall-Statured Children Aged 13 Years

    ERIC Educational Resources Information Center

    Lichota, Malgorzata

    2008-01-01

    Study aim: To assess spine curvatures, postural categories and scolioses in short and tall children aged 13 years. Material and methods: Short-statured (below Percentile 10) and tall-statured (above Percentile 90) boys (n = 13 and 18, respectively) and girls (n = 10 and 11, respectively) aged 13 years were studied. The following angles of spine…

  3. The identification of coordination constraints across planes of motion.

    PubMed

    Serrien, D J; Bogaerts, H; Suy, E; Swinnen, S P

    1999-09-01

    Two dominant coordination constraints have been identified during isofrequency conditions in previous work: the egocentric constraint, i.e., simultaneous activation of homologous muscle groups, and the allocentric constraint, i.e., moving the segments in the same direction in extrinsic space. To verify their generalization, bimanual drawing movements were performed in different planes of motion (transverse, frontal, sagittal, frontal-transverse) according to the in-phase and anti-phase mode along the X- and Y-axes. Convergent findings were obtained across the transverse, frontal, and frontal-transverse planes. The in-phase mode along both axes was performed most accurately/consistently, whereas the anti-phase mode resulted in a deterioration of the coordination pattern and this effect was most pronounced when the latter mode was introduced with respect to both dimensions. For sagittal plane motions, the in-phase mode was again superior but the second most optimal configuration was the anti-phase mode along both axes. This finding was hypothesized to result from the familiarity with the pattern since it resembles cycling behavior. It illustrates how cognitive mapping is superimposed onto the dynamics of interlimb coordination. Overall, these results support the presence of both the egocentric and allocentric constraint during bimanual movement production. PMID:10473768

  4. Coronal manifestations of preflare activity

    NASA Technical Reports Server (NTRS)

    Schmahl, E. J.; Webb, D. F.; Woodgate, B.; Waggett, P.; Bentley, R.; Hurford, G.; Schadee, A.; Schrijver, J.; Harrison, R.; Martens, P.

    1986-01-01

    A variety of coronal manifestations of precursors or preheating for flares are discussed. Researchers found that almost everyone with a telescope sees something before flares. Whether an all-encompassing scenario will ever be developed is not at all clear at present. The clearest example of preflare activity appears to be activated filaments and their manifestations, which presumably are signatures of a changing magnetic field. But researchers have seen two similar eruptions, one without any evidence of emerging flux (Kundu et al., 1985) and the other with colliding poles (Simon et al., 1984). While the reconnection of flux is generally agreed to be required to energize a flare, the emergence of flux from below (at least on short timescales and in compact regions) does not appear to be a necessary condition. In some cases the cancelling of magnetic flux (Martin, 1984) by horizontal motions instead may provide the trigger (Priest, 1985) Researchers found similarities and some differences between these and previous observations. The similarities, besides the frequent involvement of filaments, include compact, multiple precursors which can occur both at and near (not at) the flare site, and the association between coronal sources and activity lower in the atmosphere (i.e., transition zone and chromosphere).

  5. Initiation of Coronal Mass Ejections

    NASA Technical Reports Server (NTRS)

    Moore, Ronald L.; Sterling, Alphonse C.

    2005-01-01

    This paper is a synopsis of the initiation of the strong-field magnetic explosions that produce large, fast coronal mass ejections. Cartoons based on observations are used to describe the inferred basic physical processes and sequences that trigger and drive the explosion. The magnetic field that explodes is a sheared-core bipole that may or may not be embedded in surrounding strong magnetic field, and may or may not contain a flux rope before it starts to explode. We describe three different mechanisms that singly or in combination trigger the explosion: (1) runaway internal tether-cutting reconnection, (2) runaway external tether-cutting reconnection, and (3) ideal MHD instability or loss or equilibrium. For most eruptions, high-resolution, high-cadence magnetograms and chromospheric and coronal movies (such as from TRACE and/or Solar-B) of the pre-eruption region and of the onset of the eruption and flare are needed to tell which one or which combination of these mechanisms is the trigger. Whatever the trigger, it leads to the production of an erupting flux rope. Using a simple model flux rope, we demonstrate that the explosion can be driven by the magnetic pressure of the expanding flux rope, provided the shape of the expansion is "fat" enough.

  6. Coronal seismology using transverse loop oscillations

    NASA Astrophysics Data System (ADS)

    Verwichte, E.; Foullon, C.; Van Doorsselaere, T.; Smith, H. M.; Nakariakov, V. M.

    2009-12-01

    Coronal seismology exploits the properties of magnetohydrodynamics in the corona of the Sun to diagnose the local plasma. Therefore, seismology complements direct diagnostic techniques, which suffer from line-of-sight integration or may not give access to all physical quantities. In particular, the seismological exploitation of fast magnetoacoustic oscillations in coronal loops provides information about the global magnetic and density structuring of those loops acting as wave guides. From the oscillation period and damping time it is shown how to obtain information about the local coronal magnetic field as well as the longitudinal and transverse structuring. Furthermore, such studies motivate the development of coronal wave theories, which are also relevant to the coronal heating problem.

  7. Structure, chemical composition and mechanical properties of coronal cementum in human deciduous molars

    PubMed Central

    Ho, Sunita P.; Senkyrikova, Pavla; Marshall, Grayson W.; Yun, Wenbing; Wang, Yong; Karan, Kunal; Li, Cheng; Marshall, Sally J.

    2009-01-01

    Objectives It was hypothesized that the coronal cementum containing collagen forms a weak junction with enamel unlike the well integrated DEJ and CDJ. Methods The hypothesis was investigated in two parts: 1) Evaluate the structure, chemical composition and mechanical properties of coronal cementum and its junction with enamel using scanning electron microscopy, micro-X-ray computed tomography, and atomic force microscopy. The chemical composition and mechanical properties were determined by evaluating the spatial variations of inorganic (PO43− ν1 mode at 960 cm−1) and organic (C-H deformation at 1452 cm−1; C-H stretch at 2940 cm−1) contents using Raman microspectroscopy and elastic modulus and hardness values using nanoindentation. 2). Estimate the strength and evaluate the microstructure of coronal cementum interface with enamel using SEM and MicroXCT™. Results & Conclusions Coronal cementum is heterogeneous because it is a combination of laminar acellular afibrillar cementum and acellular extrinsic fiber cementum with relatively higher organic content. It integrates micromechanically via a scallop-like weak interface with enamel unlike the biomechanically efficient DEJ and CDJ and is continuous with primary root cementum. A single tooth could exhibit all three types of cementum enamel junctions; an overlap, butt and a gap depending on the sectioning plane. The elastic modulus of coronal cementum (11.0 ± 5.8 GPa) is significantly lower (p < 0.05; Student’s t-test with 95% confidence interval) than primary cementum (15.8 ± 5.3 GPa). PMID:19464049

  8. Probing Coronal Mass Ejections with Faraday Rotation

    NASA Astrophysics Data System (ADS)

    Spangler, Steven R.; Fischer, P. D.; Kooi, J. E.; Buffo, J. J.

    2013-07-01

    Coronal Mass Ejections (CMEs) are one of the most important solar phenomena in affecting conditions on Earth. There is not a consensus as to the physical mechanisms responsible for ejecting CME material from the solar atmosphere. Measurements that specify basic physical properties close to the Sun, when the CME is still evolving, should be useful in determining the correct theoretical model. One of the best observational techniques is that of Faraday rotation, a rotation in the plane of polarization of radio waves when propagating through a magnetized medium like the corona. The importance of Faraday rotation in determining the structure and evolutionary history of CMEs was discussed in Liu et al (ApJ 665, 1439, 2007). In this paper, we report Faraday rotation observations of ``constellations'' of background extragalactic radio sources near the Sun on three days in August, 2012, with the intention of observing a source occulted by a CME. Observations were made with the Jansky Very Large Array (VLA) of the National Radio Astronomy Observatory. We made polarization measurements at 6 frequencies between 1.31 and 1.94 GHz. On August 2, 2012, a CME clearly visible on the LASCO C3 coronagraph occulted a radio source from our sample, 0843+1547. Preliminary data analysis shows a Faraday rotation transient for 0843+1547 which appears to be associated with the CME. The Faraday rotation measure changes from nearly 0 before CME passage, to a value of about -12 radians/square-meter before declining after CME passage. We will discuss the interpretation of these data in terms of models for CME structure, as well as the status of our observations of other sources on August 2, and on other days. This work was supported at the University of Iowa by grant ATM09-56901.

  9. Network Coronal Bright Points: Coronal Heating Concentrations Found in the Solar Magnetic Network

    NASA Technical Reports Server (NTRS)

    Falconer, D. A.; Moore, R. L.; Porter, J. G.; Hathaway, D.

    1997-01-01

    We examine the magnetic origins of coronal heating in quiet regions by combining SOHO/EIT Fe XII coronal images and Kitt Peak magnetograms. Spatial filtering of the coronal images shows a network of enhanced structures on the scale of the magnetic network in quiet regions. Superposition of the filtered coronal images on maps of the magnetic network extracted from the magnetograms shows that the coronal network does indeed trace and stem from the magnetic network. Network coronal bright points, the brightest features in the network lanes, are found to have a highly significant (8 sigma above random chance) coincidence with polarity dividing lines (neutral lines) in the network, and are often at the feet of enhanced coronal structures that stem from the network and reach out over the cell interiors. These results indicate that, similar to the close linkage of neutral-line core fields with coronal heating in active regions, low-lying core fields encasing neutral lines in the magnetic network often drive noticeable coronal heating both within themselves (the network coronal bright points) and on more extended fields lines rooted around them. This behavior favors the possibility that active core fields in the network are the main drivers of the heating of the bulk of the quiet corona, on scales much larger than the network lanes and cells.

  10. Network Coronal Bright Points: Coronal Heating Concentrations Found in the Solar Magnetic Network

    NASA Technical Reports Server (NTRS)

    Falconer, D. A.; Moore, R. L.; Porter, J. G.; Hathaway, D. H.

    1998-01-01

    We examine the magnetic origins of coronal heating in quiet regions by combining SOHO/EIT Fe xii coronal images and Kitt Peak magnetograms. Spatial filtering of the coronal images shows a network of enhanced structures on the scale of the magnetic network in quiet regions. Superposition of the filtered coronal images on maps of the magnetic network extracted from the magnetograms shows that the coronal network does indeed trace and stem from the magnetic network. Network coronal bright points, the brightest features in the network lanes, are found to have a highly significant coincidence with polarity dividing lines (neutral lines) in the network and are often at the feet of enhanced coronal structures that stem from the network and reach out over the cell interiors. These results indicate that, similar to the close linkage of neutral-line core fields with coronal heating in active regions (shown in previous work), low-lying core fields encasing neutral lines in the magnetic network often drive noticeable coronal heating both within themselves (the network coronal bright points) and on more extended field lines rooted around them. This behavior favors the possibility that active core fields in the network are the main drivers of the heating of the bulk of the quiet corona, on scales much larger than the network lanes and cells.

  11. Fast magnetoacoustic wave trains in coronal holes

    NASA Astrophysics Data System (ADS)

    Pascoe, D. J.; Nakariakov, V. M.; Kupriyanova, E. G.

    2014-08-01

    Context. Rapidly propagating coronal EUV disturbances recently discovered in the solar corona are interpreted in terms of guided fast magnetoacoustic waves. Fast magnetoacoustic waves experience geometric dispersion in waveguides, which causes localised, impulsive perturbations to develop into quasi-periodic wave trains. Aims: We consider the formation of fast wave trains in a super-radially expanding coronal hole modelled by a magnetic funnel with a field-aligned density profile that is rarefied in comparison to the surrounding plasma. This kind of structure is typical of coronal holes, and it forms a fast magnetoacoustic anti-waveguide as a local maximum in the Alfvén speed. Methods: We performed 2D MHD numerical simulations for impulsively generated perturbations to the system. Both sausage and kink perturbations are considered and the role of the density contrast ratio investigated. Results: The anti-waveguide funnel geometry refracts wave energy away from the structure. However, in this geometry the quasi-periodic fast wave trains are found to appear, too, and so can be associated with the observed rapidly propagating coronal EUV disturbances. The wave trains propagate along the external edge of the coronal hole. The fast wave trains generated in coronal holes exhibit less dispersive evolution than in the case of a dense waveguide. Conclusions: We conclude that an impulsive energy release localised in a coronal plasma inhomogeneity develops into a fast wave train for both kink and sausage disturbances and for both waveguide and anti-waveguide transverse plasma profiles.

  12. FORWARD: A toolset for multiwavelength coronal magnetometry

    NASA Astrophysics Data System (ADS)

    Gibson, Sarah; Kucera, Therese; White, Stephen; Dove, James; Fan, Yuhong; Forland, Blake; Rachmeler, Laurel; Downs, Cooper; Reeves, Katharine

    2016-03-01

    Determining the 3D coronal magnetic field is a critical, but extremely difficult problem to solve. Since different types of multiwavelength coronal data probe different aspects of the coronal magnetic field, ideally these data should be used together to validate and constrain specifications of that field. Such a task requires the ability to create observable quantities at a range of wavelengths from a distribution of magnetic field and associated plasma -- i.e., to perform forward calculations. In this paper we describe the capabilities of the FORWARD SolarSoft IDL package, a uniquely comprehensive toolset for coronal magnetometry. FORWARD is a community resource that may be used both to synthesize a broad range of coronal observables, and to access and compare synthetic observables to existing data. It enables forward fitting of specific observations, and helps to build intuition into how the physical properties of coronal magnetic structures translate to observable properties. FORWARD can also be used to generate synthetic test beds from MHD simulations in order to facilitate the development of coronal magnetometric inversion methods, and to prepare for the analysis of future large solar telescope data.

  13. Stability Study of Coronal Cavities and Prominences

    NASA Astrophysics Data System (ADS)

    de Toma, Giuliana; Gibson, Sarah

    2016-05-01

    Cavity/prominence systems are large-scale coronal structures that can live for many weeks and even months and often end their life in the form of large coronal eruptions. To determine the role of the surrounding ambient coronal field in stabilizing thesesystems against eruption, we examined the extent to which the decline with height of the external coronal magnetic field influences their evolution and likelihood to erupt. We selected coronal cavities observed with SDO/AIA during the rising phase of cycle 24 and divided them in two groups, eruptive and non-eruptive. The height of the cavity, both at the cavity center and top, was directly measured from the SDO/AIA images. The ambient coronal field was derived from a PFSS extrapolation of SDO/HMI magnetograms. We find that the decay index of the potential field above the coronal cavity varies significantly in value for both eruptive and non-eruptive cases but stable cavity systems have, on average, a lower decay index and less complex topology than the eruptive ones.

  14. FORWARD: A Toolset for Multiwavelength Coronal Magnetometry

    NASA Technical Reports Server (NTRS)

    Gibson, Sarah E.; Kucera, Therese A.; White, Stephen M.; Dove, James B.; Fan, Yuhong; Forland, Blake C.; Rachmeler, Laurel A.; Downs, Cooper; Reeves, Katharine K.

    2016-01-01

    Determining the 3D coronal magnetic field is a critical, but extremely difficult problem to solve. Since different types of multiwavelength coronal data probe different aspects of the coronal magnetic field, ideally these data should be used together to validate and constrain specifications of that field. Such a task requires the ability to create observable quantities at a range of wavelengths from a distribution of magnetic field and associated plasma i.e., to perform forward calculations. In this paper we describe the capabilities of the FORWARD SolarSoft IDL package, a uniquely comprehensive toolset for coronal magnetometry. FORWARD is a community resource that may be used both to synthesize a broad range of coronal observables, and to access and compare synthetic observables to existing data. It enables forward fitting of specific observations, and helps to build intuition into how the physical properties of coronal magnetic structures translate to observable properties. FORWARD can also be used to generate synthetic test beds from MHD simulations in order to facilitate the development of coronal magnetometric inversion methods, and to prepare for the analysis of future large solar telescope data.

  15. Coronal Structure: Legacy of EUVE

    NASA Technical Reports Server (NTRS)

    Dupree, Andrea K,

    1999-01-01

    During this past school year, the Smithsonian Predoctoral student, Jorge Sanz-Forcada, began work on this Ph.D. thesis research which will focus on the coronal structure of active cool binary stars. He developed a semi-automatic algorithm to derive the emission measure distribution from EUVE spectra using the latest atomic parameters. To date, he has modeled our long EUVE pointing on lambda And that occurred in the fall of 1998, and has reduced and modeled spectra from EUVE pointings on AR Lac and UX Ari. Some of these observations were made simultaneous with the Advanced Satellite for Cosmology and Physics (ASCA) satellite, and the results reported at the HEAD meeting in Spring 1999.

  16. Coronal Diagnostics from Cometary Emission

    NASA Astrophysics Data System (ADS)

    Bryans, Paul; Pesnell, William D; Seaton, Daniel B; West, Matthew J

    2014-06-01

    The extreme ultraviolet (EUV) emission observed from sungrazing comets as they pass through the solar atmosphere can be used to infer the properties of the corona. In this paper we will discuss several of these properties that can be estimated from the EUV observations of Comet Lovejoy from AIA/SDO and SWAP/PROBA2. The longevity of the emission allows us to constrain the coronal electron density through which the comet passes. We will also discuss how dispersion of the emitting cometary material we can be used to estimate the local Alfven speed in the corona. Finally, measuring the deformation of the magnetic field as it is impacted by the comet can be used to estimate the magnetic field strength in this location. In the absence of the comet, none of these parameters are directly measurable in the corona. Sungrazing comets are thus unique probes of the solar atmosphere.

  17. Recent advances in coronal heating.

    PubMed

    De Moortel, Ineke; Browning, Philippa

    2015-05-28

    The solar corona, the tenuous outer atmosphere of the Sun, is orders of magnitude hotter than the solar surface. This 'coronal heating problem' requires the identification of a heat source to balance losses due to thermal conduction, radiation and (in some locations) convection. The review papers in this Theo Murphy meeting issue present an overview of recent observational findings, large- and small-scale numerical modelling of physical processes occurring in the solar atmosphere and other aspects which may affect our understanding of the proposed heating mechanisms. At the same time, they also set out the directions and challenges which must be tackled by future research. In this brief introduction, we summarize some of the issues and themes which reoccur throughout this issue. PMID:25897095

  18. The coronal-sounding experiment

    NASA Technical Reports Server (NTRS)

    Bird, M. K.; Asmar, S. W.; Brenkle, J. P.; Edenhofer, P.; Paetzold, M.; Volland, H.

    1992-01-01

    The main science objective of the Ulysses Solar Corona Experiment is to derive the plasma parameters of the solar atmosphere using established coronal-sounding techniques. Applying appropriate model assumptions, the 3D electron density distribution will be determined from dual-frequency ranging and Doppler measurements recorded at the NASA Deep Space Network during the solar conjunctions. Multi-station observations will be used to derive the plasma bulk velocity at solar distances where the solar wind is expected to undergo its greatest acceleration. As a secondary objective profiting from the favorable geometry during Jupiter encounter, radio-sounding measurements will yield a unique cross-scan of the electron density in the Io Plasma Torus.

  19. Recent advances in coronal heating

    PubMed Central

    De Moortel, Ineke; Browning, Philippa

    2015-01-01

    The solar corona, the tenuous outer atmosphere of the Sun, is orders of magnitude hotter than the solar surface. This ‘coronal heating problem’ requires the identification of a heat source to balance losses due to thermal conduction, radiation and (in some locations) convection. The review papers in this Theo Murphy meeting issue present an overview of recent observational findings, large- and small-scale numerical modelling of physical processes occurring in the solar atmosphere and other aspects which may affect our understanding of the proposed heating mechanisms. At the same time, they also set out the directions and challenges which must be tackled by future research. In this brief introduction, we summarize some of the issues and themes which reoccur throughout this issue. PMID:25897095

  20. Design and testing of a new, simple continuous bent sagittally focusing monochromator

    SciTech Connect

    Kycia, S.; Inoue, K.; Shen, Q.

    1996-09-01

    A continuous bent sagittally focusing monochromator has been designed and built. The monochromator is compatible with the present single-point bender apparatus designed for polygonal (ribbed) triangular sagittally focusing monochromators. This monochromator implements a new design concept taking advantage of a tapered rectangular wafer to allow for sagittal bending while simultaneously minimizing anticlastic bending. The monochromator was optimized to operate at x-ray energies in the range of 5 to 25 keV. The design was derived from finite element analysis using ANSYS. The monochromator performance was tested by means of an apparatus implementing an x-ray tube source and a double-crystal configuration. This method yields precise contour maps of the entire monochromator surface. Details of the monochromator design, test apparatus, and corresponding results will be presented. {copyright} {ital 1996 American Institute of Physics.}

  1. Comparing viewer and array mental rotations in different planes

    NASA Technical Reports Server (NTRS)

    Carpenter, M.; Proffitt, D. R.; Kaiser, M. K. (Principal Investigator)

    2001-01-01

    Participants imagined rotating either themselves or an array of objects that surrounded them. Their task was to report on the egocentric position of an item in the array following the imagined rotation. The dependent measures were response latency and number of errors committed. Past research has shown that self-rotation is easier than array rotation. However, we found that imagined egocentric rotations were as difficult to imagine as rotations of the environment when people performed imagined rotations in the midsagittal or coronal plane. The advantages of imagined self-rotations are specific to mental rotations performed in the transverse plane.

  2. Fishing in the Coronal Graveyard

    NASA Astrophysics Data System (ADS)

    Ayres, Thomas

    1996-07-01

    We propose a far-UV spectroscopic survey of K2-K4 giants. Hotcoronae (T> 10^6 K) are rare or absent in single giant starsto the right of a boundary in the H-R diagram near K0(``Linsky-Haisch dividing line''). The early-K giants aresuch slow rotators that the absence of Dynamo-generatedmagnetic activity is natural. Nevertheless, Gamma Draconis(K5 III) unexpectedly was detected in the coronal proxy C IVby HST/GHRS, and subsequently was discovered as a faintX-ray source in a deep ROSAT pointing. The basis for thecoronal emission is unknown, given the presumed lack of Dynamoaction. However, the X-ray/C IV ratio of Gamma Dra falls on acontinuum of values; extending from the active K0 ``Clump''giants like Beta Ceti, down to the old red giant Alpha Boo (K1III) in the depths of the ``coronal graveyard.'' GHRS/G140Lreconnaissance of high-excitation FUV emissions (Si IV, C IV,and N V) can be conducted at sensitivity levels orders ofmagnitude better than possible prior to HST. Such a surveyof single red giants would provide a unique perspective on thebreadth of activity to the right of the L-H boundary. Italso would record the fluoresced 4th-positive system of CO,a key tracer of thermal inhomogeneities in late-typeatmospheres. Seven candidates fall in the magnitude rangeV < 3. Three--Beta UMi, Epsilon Sco, and Epsilon Crv--willbe observed, consistent with the TAC allocation.

  3. Initiation of a coronal transient

    SciTech Connect

    Low, B.C.; Munro, R.H.; Fisher, R.R.

    1982-03-01

    This paper analyzes the coronal transient/eruptive prominence event of 1980 August 5 observed by the Mauna Loa experiment system. This event yielded data on the early development of the transient in the low corona between 1.2 R/sub sun/ and 2.2 R/sub sun/, information which was not available when earlier attempts were made to explain transient phenomena. The transient's initial appearance in the form of a rising density-depleted structure, prior to the eruption of the associated prominence, can be explained as an effect of magnetic buoyancy. The data indicate that this transient has a density depletion of 17% to 33% relative to an undisturbed corona which is approximately isothermal with a temperature of 1.5 x 10/sup 6/ K and a coronal density of 1.0 x 10/sup 9/ cm/sup -3/ at the base of the corona. The height versus base length relationship of the evolving transient resembles, remarkably well, the theoretical predictions obtained from a quasi-static model of a margnetically buoyant loop system. By matching this relationship with the theoretical model, we estimate the magnetic field at the base of the transient to be between 2 and 3 gauss. It is also shown that the initial, nearly constant speed of the top of the transient, 80 +- 20 km s/sup -1/, is consistent with a theoretical estimate calculated from the quasi-static model. These results suggest that some transients are not initiated impulsively, the initial stage of the development being driven by a quasi-static response to a slow change in magnetic field conditions at the base of the corona.

  4. Solar Cycle Variations of Coronal Hole Properties

    NASA Astrophysics Data System (ADS)

    Miralles, M. P.; Cranmer, S. R.; Kohl, J. L.

    2005-05-01

    As of early 2005, we have measured with the SOHO Ultraviolet Coronagraph Spectrometer (UVCS) the physical properties of at least 136 large coronal holes that produced a variety of high-speed solar wind conditions at 1 AU. UVCS has been used to observe O VI (103.2 and 103.7 nm) and H I Lyman alpha (121.6 nm) emission lines as a function of heliocentric distance in coronal holes since 1996. The analysis of their spectroscopic parameters allows us to identify similarities and differences among coronal holes at different phases of the solar cycle. From such measurements we can derive plasma parameters (densities, temperatures, velocity distribution anisotropies, and outflow speeds) for O5+ and protons as a function of heliocentric distance in the coronal holes. These properties, combined with other observed quantities such as white-light polarization brightness and the more-or-less unipolar magnetic fluxes measured on-disk, let us map out the "allowed parameter space" of coronal hole plasma properties more fully than ever before. We will present the solar cycle dependence of the above plasma parameters from the last solar minimum in 1996 to present and compare them, where possible, with the in situ solar wind properties. We will also present an update on the pattern that is beginning to emerge, i.e., coronal holes with lower densities at a given heliocentric distance tend to exhibit faster ion outflow and higher ion temperatures. This information will thus be used to set firm empirical constraints on coronal heating and solar wind acceleration in coronal holes. In 2005, the polar coronal holes have not yet evolved to the fully quiescent minimum state seen in 1996-1997, though the next solar minimum is expected to occur in about 1.5 to 2 years. This work is supported by NASA under Grant NNG04GE84G to the Smithsonian Astrophysical Observatory, by the Italian Space Agency, and by PRODEX (Swiss contribution).

  5. Slipping magnetic reconnection in coronal loops.

    PubMed

    Aulanier, Guillaume; Golub, Leon; Deluca, Edward E; Cirtain, Jonathan W; Kano, Ryouhei; Lundquist, Loraine L; Narukage, Noriyuki; Sakao, Taro; Weber, Mark A

    2007-12-01

    Magnetic reconnection of solar coronal loops is the main process that causes solar flares and possibly coronal heating. In the standard model, magnetic field lines break and reconnect instantaneously at places where the field mapping is discontinuous. However, another mode may operate where the magnetic field mapping is continuous but shows steep gradients: The field lines may slip across each other. Soft x-ray observations of fast bidirectional motions of coronal loops, observed by the Hinode spacecraft, support the existence of this slipping magnetic reconnection regime in the Sun's corona. This basic process should be considered when interpreting reconnection, both on the Sun and in laboratory-based plasma experiments. PMID:18063789

  6. A new instrumentation project for the Lomnicky stit coronal station

    NASA Astrophysics Data System (ADS)

    Rybak, J.

    1993-07-01

    A proposal of a new telescope/auxiliary instrumentation system for the solar coronal station at Lomnicky Stit (2632 m asl) is described in both the general concept and some particular technical details. The main aim of the system is to observe the near-limb photospheric and chromospheric layers of the solar atmosphere by the white-light and narrow-band imaging, as well as to perform the visible and near-infrared spectroscopy and spectropolarimetry of the parts of solar disk already mentioned. These sorts of data, measured simultaneously with the coronal emission line profiles which are regularly obtained at this time by coronagraph, could give us a great amount of physical information about the solar activity events (such as the height distribution of energy, mass, magnetic fields and their time evolution). The initial ideas and motivation of the project are explained. The parameters of the system components - refractors, narrow band filters, focal plane detectors and fibre optics positioners, telescope-spectrograph coupling via fiber optics, spectrographs, detectors and computers for the control of observations and the data acquisition - are discussed. TV CCD detectors connected with the advanced frame grabbers and the IBM PC computers are especially taken into account for the data acquisition. We also briefly mention advantages and disadvantages of the system as a whole. Finally, the future prospects of the project proposal are briefly described.

  7. LOW-LATITUDE CORONAL HOLES, DECAYING ACTIVE REGIONS, AND GLOBAL CORONAL MAGNETIC STRUCTURE

    SciTech Connect

    Petrie, G. J. D.; Haislmaier, K. J.

    2013-10-01

    We study the relationship between decaying active-region magnetic fields, coronal holes, and the global coronal magnetic structure using Global Oscillations Network Group synoptic magnetograms, Solar TErrestrial RElations Observatory extreme-ultraviolet synoptic maps, and coronal potential-field source-surface models. We analyze 14 decaying regions and associated coronal holes occurring between early 2007 and late 2010, 4 from cycle 23 and 10 from cycle 24. We investigate the relationship between asymmetries in active regions' positive and negative magnetic intensities, asymmetric magnetic decay rates, flux imbalances, global field structure, and coronal hole formation. Whereas new emerging active regions caused changes in the large-scale coronal field, the coronal fields of the 14 decaying active regions only opened under the condition that the global coronal structure remained almost unchanged. This was because the dominant slowly varying, low-order multipoles prevented opposing-polarity fields from opening and the remnant active-region flux preserved the regions' low-order multipole moments long after the regions had decayed. Thus, the polarity of each coronal hole necessarily matched the polar field on the side of the streamer belt where the corresponding active region decayed. For magnetically isolated active regions initially located within the streamer belt, the more intense polarity generally survived to form the hole. For non-isolated regions, flux imbalance and topological asymmetry prompted the opposite to occur in some cases.

  8. Relating magnetic reconnection to coronal heating

    PubMed Central

    Longcope, D. W.; Tarr, L. A.

    2015-01-01

    It is clear that the solar corona is being heated and that coronal magnetic fields undergo reconnection all the time. Here we attempt to show that these two facts are related—i.e. coronal reconnection generates heat. This attempt must address the fact that topological change of field lines does not automatically generate heat. We present one case of flux emergence where we have measured the rate of coronal magnetic reconnection and the rate of energy dissipation in the corona. The ratio of these two, , is a current comparable to the amount of current expected to flow along the boundary separating the emerged flux from the pre-existing flux overlying it. We can generalize this relation to the overall corona in quiet Sun or in active regions. Doing so yields estimates for the contribution to coronal heating from magnetic reconnection. These estimated rates are comparable to the amount required to maintain the corona at its observed temperature. PMID:25897089

  9. Solar cycle variations of coronal structures

    NASA Astrophysics Data System (ADS)

    Loucif, M. L.; Koutchmy, S.

    1989-01-01

    Using eclipse pictures of the solar corona, properly scaled drawings have been prepared to constitute a short atlas of coronal structures. These drawings have been used to extract 2 parameters which are further considered with respect to the sunspot number and the sunspot cycle: the extension of polar regions free of coronal streamers and the average radial deviation of large streamers. The flattening index deduced from the photometric analysis of a larger number of eclipse pictures is also considered. The out-of-phase behavior of several coronal parameters is confirmed. The results are discussed in the light of the analysis of the green-line activity as observed during 30 years at the Pic du Midi Observatory. The N-S asymmetric behavior of the activity in different solar hemispheres and the occurrence of a powerful secondary maximum of coronal activity are discussed.

  10. Aug. 31, 2012 Coronal Mass Ejection

    NASA Video Gallery

    This two part movie shows an Aug. 31 coronal mass ejection (CME) from the sun , the same event that caused depletion and refilling of the radiation belts just after the Relativistic Electron-Proton...

  11. Coronal Magnetism and Forward Solarsoft Idl Package

    NASA Astrophysics Data System (ADS)

    Gibson, S. E.

    2014-12-01

    The FORWARD suite of Solar Soft IDL codes is a community resource for model-data comparison, with a particular emphasis on analyzing coronal magnetic fields. FORWARD may be used both to synthesize a broad range of coronal observables, and to access and compare to existing data. FORWARD works with numerical model datacubes, interfaces with the web-served Predictive Science Inc MAS simulation datacubes and the Solar Soft IDL Potential Field Source Surface (PFSS) package, and also includes several analytic models (more can be added). It connects to the Virtual Solar Observatory and other web-served observations to download data in a format directly comparable to model predictions. It utilizes the CHIANTI database in modeling UV/EUV lines, and links to the CLE polarimetry synthesis code for forbidden coronal lines. FORWARD enables "forward-fitting" of specific observations, and helps to build intuition into how the physical properties of coronal magnetic structures translate to observable properties.

  12. Sept. 28, 2012 Coronal Mass Ejection

    NASA Video Gallery

    This Sept. 28 coronal mass ejection (CME) from the sun, captured by NASA’s Solar Dynamics Observatory (SDO), is the event which caused the near total annihilation of the new radiation belt and sl...

  13. Solar Coronal Cells as Seen by STEREO

    NASA Video Gallery

    The changes of a coronal cell region as solar rotation carries it across the solar disk as seen with NASA's STEREO-B spacecraft. The camera is fixed on the region (panning with it) and shows the pl...

  14. Observational Consequences of Coronal Heating Mechanisms

    NASA Technical Reports Server (NTRS)

    Winebarger, Amy R.; Cirtain, Jonathan C.; Golub, Leon; Kobayashi, Ken

    2014-01-01

    The coronal heating problem remains unsolved today, 80 years after its discovery, despite 50 years of suborbital and orbital coronal observatories. Tens of theoretical coronal heating mechanisms have been suggested, but only a few have been able to be ruled out. In this talk, we will explore the reasons for the slow progress and discuss the measurements that will be needed for potential breakthrough, including imaging the solar corona at small spatial scales, measuring the chromospheric magnetic fields, and detecting the presence of high temperature, low emission measure plasma. We will discuss three sounding rocket instruments developed to make these measurements: the High resolution Resolution Coronal Imager (Hi-C), the Chromospheric Lyman-Alpha Spectropolarimeter (CLASP), and the Marshall Grazing Incidence X-ray Spectrometer (MaGIXS).

  15. Coronal magnetic fields and the solar wind

    NASA Technical Reports Server (NTRS)

    Newkirk, G., Jr.

    1972-01-01

    Current information is presented on coronal magnetic fields as they bear on problems of the solar wind. Both steady state fields and coronal transient events are considered. A brief critique is given of the methods of calculating coronal magnetic fields including the potential (current free) models, exact solutions for the solar wind and field interaction, and source surface models. These solutions are compared with the meager quantitative observations which are available at this time. Qualitative comparisons between the shapes of calculated magnetic field lines and the forms visible in the solar corona at several recent eclipses are displayed. These suggest that: (1) coronal streamers develop above extended magnetic arcades which connect unipolar regions of opposite polarity; and (2) loops, arches, and rays in the corona correspond to preferentially filled magnetic tubes in the approximately potential field.

  16. Results of coronal hole research: An overview

    NASA Technical Reports Server (NTRS)

    Wilson, R. M.

    1976-01-01

    An overview of the last 10 years of coronal hole research, in particular since 1970, is presented. The findings of the early investigations and the more recent results obtained with Skylab/Apollo Telescope Mount instrumentation are discussed.

  17. Interpretive Tools for Analysis of Coronal Images

    NASA Technical Reports Server (NTRS)

    Ofman, Leon

    2004-01-01

    Contents include list of publications resulting from grant: Magneto-Hydrodynamic Model of the Solar Corona and Interplanetary Medium. Coronal magnetic field topology and source of fast solar wind. Geophysical Importance of Global Magnetic Field Geometry and Density Distribution in Solar Wind Modeling. Empirical Model of the Corona-Solar Wind with Multiple Current Sheets. Model of the Solar Wind and its Comparison with ULYSSES. Physical properties of a coronal hole from a coronal diagnostic spectrometer, Mauna Loa Coronagraph, and LASCO observations during the Whole Sun Month. Semi-Empirical 2-D MHD Model of the Solar corona and Solar Wind: Energy Flow in the Corona. Source Region of High and Low Speed Wind during the Spartan. Three-dimensional coronal density structure. Cone Model for Halo CME's: Application to Space Weather Forecasting.

  18. Skeletal stability after bilateral sagittal split osteotomy or distraction osteogenesis of the mandible: a randomized clinical trial.

    PubMed

    Baas, E M; Bierenbroodspot, F; de Lange, J

    2015-05-01

    A randomized clinical trial was carried out to evaluate postoperative stability after mandibular advancements in non-syndromal class II patients with a bilateral sagittal split osteotomy (BSSO) or distraction osteogenesis (DO). In total 32 patients could be included in the BSSO group and 34 patients in the DO group. The BSSO was converted to a unilateral procedure for one patient, and two patients in the BSSO group were lost during follow-up. A total 63 patients could be evaluated, 29 in the BSSO group and 34 in the DO group. Advancement was comparable in the two groups (mean 7.2mm). The mean follow-up period was 23.8 months (range 11-50 months). Lateral cephalograms were hand-traced. Horizontal relapse was measured in Y-B (mm) and SNB (°). For DO this was -0.324 mm and -0.250°, and for BSSO this was -0.448 mm and -0.259°, respectively (both not significant; NS). Vertical relapse measured in X-B was -0.074 mm for DO and -0.034 mm for BSSO (NS). The magnitude of advancement, a high mandibular plane angle, age and gender were not identified as independent risk factors for relapse. In conclusion, a BSSO and DO gave both similar stable results in advancements of the mandible up to 10mm. PMID:25595452

  19. Energy conversion in the coronal plasma

    NASA Technical Reports Server (NTRS)

    Martens, P. C. H.

    1986-01-01

    Solar and stellar X-ray emission are the observed waste products of the interplay between magnetic fields and the motion of stellar plasma. Theoretical understanding of the process of coronal heating is of utmost importance, since the high temperature is what defines the corona in the first place. Most of the research described deals with the aspects of the several rivalling theories for coronal heating. The rest of the papers deal with processes of energy conversion related to flares.

  20. Changes in Habitual and Active Sagittal Posture in Children and Adolescents with and without Visual Input – Implications for Diagnostic Analysis of Posture

    PubMed Central

    Mazet, Carola; Mazet, Dirk; Hammes, Annette; Schmitt, Eduard

    2016-01-01

    Introduction Poor posture in children and adolescents has a prevalence of 22-65% and is suggested to be responsible for back pain. To assess posture, photometric imaging of sagittal posture is widely used, but usually only habitual posture positions (resting position with minimal muscle activity) are analysed. Aim The objective of this study was 1) to investigate possible changes in posture-describing parameters in the sagittal plane, when the subjects changed from a habitual passive posture to an actively corrected posture, and 2) to investigate the changes in posture parameters when an actively corrected posture was to be maintained with closed eyes. Materials and Methods In a group of 216 male children and adolescents (average 12.4 ± 2.5 years, range 7.0 – 17.6 years), six sagittal posture parameters (body tilt BT, trunk incline TI, posture index PI, horizontal distances between ear, shoulder and hip and the perpendicular to the ankle joint) were determined by means of photometric imaging in an habitual passive posture position, in an actively erect posture with eyes open, and in active stance with eyes closed. The change in these parameters during the transition between the posture positions was analysed statistically (dependent t-Test or Wilcoxon-Test) after Bonferroni correction (p<0.004). Results When moving from a habitual passive to an active posture BT, TI, PI, dEar, dShoulder, and dHip decreased significantly(p< 0.004). When the eyes were closed, only the perpendicular distances (dEar, dShoulder, and dHip) increased significantly. The parameters that describe the alignment of the trunk sections in relation to each other (BT, TI, PI), remained unchanged in both actively regulated posture positions. Conclusion Changes in sagittal posture parameters that occur when a habitual passive posture switches into an active posture or when an active posture is to be maintained while the eyes are closed can be used for diagnostic purposes regarding poor posture

  1. Dynamic simulation of coronal mass ejections

    NASA Technical Reports Server (NTRS)

    Steinolfson, R. S.; Wu, S. T.

    1980-01-01

    A model is developed for the formation and propagation through the lower corona of the loop-like coronal transients in which mass is ejected from near the solar surface to the outer corona. It is assumed that the initial state for the transient is a coronal streamer. The initial state for the streamer is a polytropic, hydrodynamic solution to the steady-state radial equation of motion coupled with a force-free dipole magnetic field. The numerical solution of the complete time-dependent equations then gradually approaches a stationary coronal streamer configuration. The streamer configuration becomes the initial state for the coronal transient. The streamer and transient simulations are performed completely independent of each other. The transient is created by a sudden increase in the pressure at the base of the closed-field region in the streamer configuration. Both coronal streamers and coronal transients are calculated for values of the plasma beta (the ratio of thermal to magnetic pressure) varying from 0.1 to 100.

  2. MULTIDIMENSIONAL MODELING OF CORONAL RAIN DYNAMICS

    SciTech Connect

    Fang, X.; Xia, C.; Keppens, R.

    2013-07-10

    We present the first multidimensional, magnetohydrodynamic simulations that capture the initial formation and long-term sustainment of the enigmatic coronal rain phenomenon. We demonstrate how thermal instability can induce a spectacular display of in situ forming blob-like condensations which then start their intimate ballet on top of initially linear force-free arcades. Our magnetic arcades host a chromospheric, transition region, and coronal plasma. Following coronal rain dynamics for over 80 minutes of physical time, we collect enough statistics to quantify blob widths, lengths, velocity distributions, and other characteristics which directly match modern observational knowledge. Our virtual coronal rain displays the deformation of blobs into V-shaped features, interactions of blobs due to mostly pressure-mediated levitations, and gives the first views of blobs that evaporate in situ or are siphoned over the apex of the background arcade. Our simulations pave the way for systematic surveys of coronal rain showers in true multidimensional settings to connect parameterized heating prescriptions with rain statistics, ultimately allowing us to quantify the coronal heating input.

  3. Multidimensional Modeling of Coronal Rain Dynamics

    NASA Astrophysics Data System (ADS)

    Fang, X.; Xia, C.; Keppens, R.

    2013-07-01

    We present the first multidimensional, magnetohydrodynamic simulations that capture the initial formation and long-term sustainment of the enigmatic coronal rain phenomenon. We demonstrate how thermal instability can induce a spectacular display of in situ forming blob-like condensations which then start their intimate ballet on top of initially linear force-free arcades. Our magnetic arcades host a chromospheric, transition region, and coronal plasma. Following coronal rain dynamics for over 80 minutes of physical time, we collect enough statistics to quantify blob widths, lengths, velocity distributions, and other characteristics which directly match modern observational knowledge. Our virtual coronal rain displays the deformation of blobs into V-shaped features, interactions of blobs due to mostly pressure-mediated levitations, and gives the first views of blobs that evaporate in situ or are siphoned over the apex of the background arcade. Our simulations pave the way for systematic surveys of coronal rain showers in true multidimensional settings to connect parameterized heating prescriptions with rain statistics, ultimately allowing us to quantify the coronal heating input.

  4. [Progressive Intracranial Hypertension due to Superior Sagittal Sinus Thrombosis Following Mild Head Trauma: A Case Report].

    PubMed

    Suto, Yuta; Maruya, Jun; Watanabe, Jun; Nishimaki, Keiichi

    2015-07-01

    Cerebral venous sinus thrombosis after mild head trauma without skull fracture or intracranial hematoma is exceptionally rare. We describe an unusual case of progressive intracranial hypertension due to superior sagittal sinus thrombosis following mild head trauma. A 17-year-old boy presented with nape pain a day after a head blow during a gymnastics competition (backward double somersault). On admission, he showed no neurological deficit. CT scans revealed no skull fractures, and there were no abnormalities in the brain parenchyma. However, his headache worsened day-by-day and he had begun to vomit. Lumbar puncture was performed on Day 6, and the opening pressure was 40 cm of water. After tapping 20 mL, he felt better and the headache diminished for a few hours. MR venography performed on Day 8 revealed severe flow disturbance in the posterior third of the superior sagittal sinus with multiple venous collaterals. Because of the beneficial effects of lumbar puncture, we decided to manage his symptoms of intracranial hypertension conservatively with repeated lumbar puncture and administration of glycerol. After 7 days of conservative treatment, his symptoms resolved completely, and he was discharged from the hospital. Follow-up MR venography performed on Day 55 showed complete recanalization of the superior sagittal sinus. The exact mechanism of sinus thrombosis in this case is not clear, but we speculate that endothelial damage caused by shearing stress because of strong rotational acceleration or direct impact to the superior sagittal sinus wall may have initiated thrombus formation. PMID:26136327

  5. Sagittal alignment of the spine-pelvis-lower extremity axis in patients with severe knee osteoarthritis

    PubMed Central

    Wang, W. J.; Liu, F.; Zhu, Y.W.; Sun, M.H.; Qiu, Y.

    2016-01-01

    Objectives Normal sagittal spine-pelvis-lower extremity alignment is crucial in humans for maintaining an ergonomic upright standing posture, and pathogenesis in any segment leads to poor balance. The present study aimed to investigate how this sagittal alignment can be affected by severe knee osteoarthritis (KOA), and whether associated changes corresponded with symptoms of lower back pain (LBP) in this patient population. Methods Lateral radiograph films in an upright standing position were obtained from 59 patients with severe KOA and 58 asymptomatic controls free from KOA. Sagittal alignment of the spine, pelvis, hip and proximal femur was quantified by measuring several radiographic parameters. Global balance was accessed according to the relative position of the C7 plumb line to the sacrum and femoral heads. The presence of chronic LBP was documented. Comparisons between the two groups were carried by independent samples t-tests or chi-squared test. Results Patients with severe KOA showed significant backward femoral inclination (FI), hip flexion, forward spinal inclination, and higher prevalence of global imbalance (27.1% versus 3.4%, p < 0.001) compared with controls. In addition, patients with FI of 10° (n = 23) showed reduced lumbar lordosis and significant forward spinal inclination compared with controls, whereas those with FI > 10° (n = 36) presented with significant pelvic anteversion and hip flexion. A total of 39 patients with KOA (66.1%) suffered from LBP. There was no significant difference in sagittal alignment between KOA patients with and without LBP. Conclusions The sagittal alignment of spine-pelvis-lower extremity axis was significantly influenced by severe KOA. The lumbar spine served as the primary source of compensation, while hip flexion and pelvic anteversion increased for further compensation. Changes in sagittal alignment may not be involved in the pathogenesis of LBP in this patient population. Cite this article: W. J. Wang, F. Liu

  6. Characteristics of Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Talukder, F.; Marchese, A. K.; Tulsee, T.

    2014-12-01

    A coronal mass ejection (CME) is a release of charged particles resulting from solar activity. These charged particles can affect electronics on spacecraft, airplanes, global positioning systems, and communication satellites. The purpose of this research was to study CME data from satellites and correlate these to other properties. Solar wind data collected by STEREO A/B and ACE satellites were analyzed. The data consisted of solar wind flux for various elements (helium through iron), as well as the components of the interplanetary magnetic field. CME events are known to cause a surge in the helium flux, as well as other particles. It is hypothesized that a CME event will cause an increase in the number of lighter elements relative to heavier particles. This is because for a given input of energy, lighter elements are expected to be accelerated to a greater extent than heavier elements. A significant increase was observed in the ratio between helium to oxygen (He/O) prior to intense CMEs. A CME event on November 4, 2003 caused an eleven-fold increase in the He/O ratio, while for another event on April 2, 2001 the He/O ratio increased from 80 to 700. A significant increase in He/O ratio is not observed during weaker CMEs. Furthermore, it was also observed that not all increases in the ratio were accompanied by CMEs. The increase in He/O ratio prior to the CME arrival might be used as a way to predict future events.

  7. Composition of Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Zurbuchen, T. H.; Weberg, M.; von Steiger, R.; Mewaldt, R. A.; Lepri, S. T.; Antiochos, S. K.

    2016-07-01

    We analyze the physical origin of plasmas that are ejected from the solar corona. To address this issue, we perform a comprehensive analysis of the elemental composition of interplanetary coronal mass ejections (ICMEs) using recently released elemental composition data for Fe, Mg, Si, S, C, N, Ne, and He as compared to O and H. We find that ICMEs exhibit a systematic abundance increase of elements with first ionization potential (FIP) < 10 eV, as well as a significant increase of Ne as compared to quasi-stationary solar wind. ICME plasmas have a stronger FIP effect than slow wind, which indicates either that an FIP process is active during the ICME ejection or that a different type of solar plasma is injected into ICMEs. The observed FIP fractionation is largest during times when the Fe ionic charge states are elevated above Q Fe > 12.0. For ICMEs with elevated charge states, the FIP effect is enhanced by 70% over that of the slow wind. We argue that the compositionally hot parts of ICMEs are active region loops that do not normally have access to the heliosphere through the processes that give rise to solar wind. We also discuss the implications of this result for solar energetic particles accelerated during solar eruptions and for the origin of the slow wind itself.

  8. The Global Coronal Structure Investigation

    NASA Astrophysics Data System (ADS)

    Golub, Leon

    1998-02-01

    During the past year we have completed the changeover from the NIXT program to the new TXI sounding rocket program. The NIXT effort, aimed at evaluating the viability of the remaining portions of the NIXT hardware and design, has been finished and the portions of the NIXT which are viable and flightworthy, such as filters, mirror mounting hardware, electronics and telemetry interface systems, are now part of the new rocket payload. The backup NIXT multilayer-coated x-ray telescope and its mounting hardware have been completely fabricated and are being stored for possible future use in the TXI rocket. The H-alpha camera design is being utilized in the TXI program for real-time pointing verification and control via telemetry. A new H-alpha camera has been built, with a high-resolution RS170 CCD camera output. Two papers, summarizing scientific results from the NIXT rocket program, have been written and published this year: 1. "The Solar X-ray Corona," by L. Golub, Astrophysics and Space Science, 237, 33 (1996). 2. "Difficulties in Observing Coronal Structure," Keynote Paper, Proceedings STEPWG1 Workshop on Measurements and Analyses of the Solar 3D Magnetic Field, Solar Physics, 174, 99 (1997).

  9. The Global Coronal Structure Investigation

    NASA Technical Reports Server (NTRS)

    Golub, Leon

    1998-01-01

    During the past year we have completed the changeover from the NIXT program to the new TXI sounding rocket program. The NIXT effort, aimed at evaluating the viability of the remaining portions of the NIXT hardware and design, has been finished and the portions of the NIXT which are viable and flightworthy, such as filters, mirror mounting hardware, electronics and telemetry interface systems, are now part of the new rocket payload. The backup NIXT multilayer-coated x-ray telescope and its mounting hardware have been completely fabricated and are being stored for possible future use in the TXI rocket. The H-alpha camera design is being utilized in the TXI program for real-time pointing verification and control via telemetry. A new H-alpha camera has been built, with a high-resolution RS170 CCD camera output. Two papers, summarizing scientific results from the NIXT rocket program, have been written and published this year: 1. "The Solar X-ray Corona," by L. Golub, Astrophysics and Space Science, 237, 33 (1996). 2. "Difficulties in Observing Coronal Structure," Keynote Paper, Proceedings STEPWG1 Workshop on Measurements and Analyses of the Solar 3D Magnetic Field, Solar Physics, 174, 99 (1997).

  10. Coronal Structures in Cool Stars

    NASA Technical Reports Server (NTRS)

    Oliversen, Ronald (Technical Monitor); Dupree, Andrea K.

    2004-01-01

    Many papers have been published that further elucidate the structure of coronas in cool stars as determined from EUVE, HST, FUSE, Chandra, and XMM-Newton observations. In addition we are exploring the effects of coronas on the He I 1083081 transition that is observed in the infrared. Highlights of these are summarized below including publications during this reporting period and presentations. Ground-based magnetic Doppler imaging of cool stars suggests that active stars have active regions located at high latitudes on their surface. We have performed similar imaging in X-ray to locate the sites of enhanced activity using Chandra spectra. Chandra HETG observations of the bright eclipsing contact binary 44i Boo and Chandra LETG observations for the eclipsing binary VW Cep show X-ray line profiles that are Doppler-shifted by orbital motion. After careful analysis of the spectrum of each binary, a composite line-profile is constructed by adding the individual spectral lines. This high signal-to-noise ratio composite line-profile yields orbital velocities for these binaries that are accurate to 30 km/sec and allows their orbital motion to be studied at higher time resolutions. In conjunction with X-ray lightcurves, the phase-binned composite line-profiles constrain coronal structures to be small and located at high latitudes. These observations and techniques show the power of the Doppler Imaging Technique applied to X-ray line emission.