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patterns of head motion

Ziying Yin, Yi Sui, Joshua D Trzasko, Phillip J Rossman, Armando Manduca, Richard L Ehman, John Huston
PURPOSE: To introduce newly developed MR elastography (MRE)-based dual-saturation imaging and dual-sensitivity motion encoding schemes to directly measure in vivo skull-brain motion, and to study the skull-brain coupling in volunteers with these approaches. METHODS: Six volunteers were scanned with a high-performance compact 3T-MRI scanner. The skull-brain MRE images were obtained with a dual-saturation imaging where the skull and brain motion were acquired with fat- and water-suppression scans, respectively...
May 17, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Kevin W Rio, Gregory C Dachner, William H Warren
It is commonly believed that global patterns of motion in flocks, schools and crowds emerge from local interactions between individuals, through a process of self-organization. The key to explaining such collective behaviour thus lies in deciphering these local interactions. We take an experiment-driven approach to modelling collective motion in human crowds. Previously, we observed that a pedestrian aligns their velocity vector (speed and heading direction) with that of a neighbour. Here we investigate the neighbourhood of interaction in a crowd: which neighbours influence a pedestrian's behaviour, how this depends on neighbour position, and how the influences of multiple neighbours are combined...
May 16, 2018: Proceedings. Biological Sciences
Felix Dyrna, Neil S Kumar, Elifho Obopilwe, Bastian Scheiderer, Brendan Comer, Michael Nowak, Anthony A Romeo, Augustus D Mazzocca, Knut Beitzel
BACKGROUND: Previous biomechanical studies regarding deltoid function during glenohumeral abduction have primarily used static testing protocols. HYPOTHESES: (1) Deltoid forces required for scapular plane abduction increase as simulated rotator cuff tears become larger, and (2) maximal abduction decreases despite increased deltoid forces. STUDY DESIGN: Controlled laboratory study. METHODS: Twelve fresh-frozen cadaveric shoulders with a mean age of 67 years (range, 64-74 years) were used...
May 1, 2018: American Journal of Sports Medicine
Christian Balkovec, Jim Veldhuis, John W Baird, G Wayne Brodland, Stuart M McGill
BACKGROUND: Disc height loss and osteophytes change the local mechanical environment in the spine; while previous research has examined kinematic dysfunction under degenerative change, none has looked at the influence of disc height loss and osteophytes throughout movement. METHODS: Twenty patients with pain related to the head, neck or shoulders were imaged via videofluoroscopy as they underwent sagittal-plane flexion and extension. A clinician graded disc height loss and osteophytes as "severe/moderate", "mild", or "none"...
April 26, 2018: Clinical Biomechanics
Y H Chiang, S L Tsai, S R Tee, O L Nair, I Y Loh, M H Liu, Z S Wang
Nanowalkers take either inchworm (IW) or hand-over-hand (HOH) gait. The IW nanowalkers are advantageous over HOH ones in force generation, processivity and high-density integration, though both gaits occur in intracellular nanowalkers from biology. Artificial IW nanowalkers have been realized or proposed, but all rely on different 'head' and 'tail' to gain an adventitious direction. Here we report an inherently unidirectional IW nanowalker that is a biped with two identical legs (i.e., indistinguishable 'head' and 'tail')...
May 4, 2018: Nanoscale
Rocco Marchitelli, Marco Aiello, Arnaud Cachia, Mario Quarantelli, Carlo Cavaliere, Alfredo Postiglione, Gioacchino Tedeschi, Patrizia Montella, Graziella Milan, Marco Salvatore, Elena Salvatore, Jean Claude Baron, Sabina Pappatà
Simultaneously evaluating resting-state brain glucose metabolism and intrinsic functional activity has potential to impact the clinical neurosciences of Alzheimer Disease (AD). Indeed, integrating such combined information obtained in the same physiological setting may clarify how impairments in neuroenergetic and neuronal function interact and contribute to the mechanisms underlying AD. The present study used this multimodality approach to investigate, by means of a hybrid PET/MR scanner, the coupling between glucose consumption and intrinsic functional activity in 23 patients with AD-related cognitive impairment ranging from amnestic mild cognitive impairment (MCI) to mild-moderate AD (aMCI/AD), in comparison with a group of 23 healthy elderly controls...
April 27, 2018: NeuroImage
Michael Psarakis, David Greene, Michael H Cole, Stephen R Lord, Phu Hoang, Matthew A D Brodie
People with Multiple Sclerosis (PwMS) often experience a decline in gait performance, which can compromise their independence and increase falls. Ankle joint contractures in PwMS are common and often result in compensatory gait patterns to accommodate reduced ankle range of motion (ROM). Using advances in wearable technology, the aim of this study was to quantify head and pelvis movement patterns that occur in PwMS with disability and determine how these secondary gait compensations impact on gait stability...
April 27, 2018: Physiological Measurement
M Rhodin, E Persson-Sjodin, A Egenvall, F M Serra Bragança, T Pfau, L Roepstorff, M A Weishaupt, M H Thomsen, P R van Weeren, E Hernlund
BACKGROUND: The main criteria for lameness assessment in horses are head movement for forelimb lameness and pelvic movement for hindlimb lameness. However, compensatory head nod in horses with primary hindlimb lameness is a well-known phenomenon. This compensatory head nod movement can be easily misinterpreted as a sign of primary ipsilateral forelimb lameness. Therefore, discriminating compensatory asymmetries from primary directly pain-related movement asymmetries is a prerequisite for successful lameness assessment...
April 15, 2018: Equine Veterinary Journal
Franciszek Hennel, Rui Tian, Maria Engel, Klaas P Pruessmann
PURPOSE: Acquisition of high-resolution imaging data using multiple excitations without the sensitivity to fluctuations of the transverse magnetization phase, which is a major problem of multi-shot MRI. THEORY AND METHODS: The concept of superresolution MRI based on microscopic tagging is analyzed using an analogy with the optical method of structured illumination. Sinusoidal tagging is shown to provide subpixel resolution by mixing of neighboring spatial frequency (k-space) bands...
April 15, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Rishi Kumar Gupta, Dilip Kumar Swain, Vijay Singh, Mukul Anand, Soumen Choudhury, Sarvajeet Yadav, Atul Saxena, Satish Kumar Garg
Present study was undertaken to characterize the voltage gated potassium channel (Kv 1.1) in bull spermatozoa using sixty four ejaculates collected from four Hariana bulls. Functional characterization was undertaken using a selective blocker of Kv channel, 4-Aminopyridine (4-AP) while molecular presence of Kv on bull spermatozoa by immunoblotting and indirect immunofluorescence. Three sets of 100 μL diluted sperm samples namely-negative control (100 μL of sperm dilution medium (SDM) containing 10 × 106  cells), vehicle control (99 μL of SDM containing 10 × 106  cells, and DMSO- 1  μL) and 4-AP treatment group (99 μL of SDM containing 10 × 106  cells, and drug 1 μL 4-AP) were used in the study...
March 26, 2018: Theriogenology
Sergii Boryshpolets, Vitaliy Kholodnyy, Jacky Cosson, Borys Dzyuba
Motility analysis of spermatozoa relies on the investigation of either head trajectories or flagellum characteristics. Those two sets of parameters are far from being independent, the flagellum playing the role of motor, whereas the head plays a passive role of cargo. Therefore, quantitative descriptions of head trajectories represent a simplification of the complex pattern of whole sperm cell motion, resulting from the waves developed by the flagellum. The flagellum itself responds to a large variety of signals that precisely control its axoneme to allow activation, acceleration, slowing down or reorientation of the whole spermatozoon...
April 13, 2018: Reproduction, Fertility, and Development
Eric R Castillo, Daniel E Lieberman
During locomotion, each step generates a shock wave that travels through the body toward the head. Without mechanisms for attenuation, repeated shocks can lead to pathology. Shock attenuation (SA) in the lower limb has been well studied, but little is known about how posture affects SA in the spine. To test the hypothesis that lumbar lordosis (LL) contributes to SA, 27 adults (14 male, 13 female) walked and ran on a treadmill. Two lightweight, tri-axial accelerometers were affixed to the skin overlying T12/L1 and L5/S1...
April 5, 2018: Journal of Experimental Biology
Steffi Dreha-Kulaczewski, Mareen Konopka, Arun A Joseph, Jost Kollmeier, Klaus-Dietmar Merboldt, Hans-Christoph Ludwig, Jutta Gärtner, Jens Frahm
The dynamics of human CSF in brain and upper spinal canal are regulated by inspiration and connected to the venous system through associated pressure changes. Upward CSF flow into the head during inspiration counterbalances venous flow out of the brain. Here, we investigated CSF motion along the spinal canal by real-time phase-contrast flow MRI at high spatial and temporal resolution. Results reveal a watershed of spinal CSF dynamics which divides flow behavior at about the level of the heart. While forced inspiration prompts upward surge of CSF flow volumes in the entire spinal canal, ensuing expiration leads to pronounced downward CSF flow, but only in the lower canal...
April 4, 2018: Scientific Reports
John A Perrone
Motion along curved paths (curvilinear self-motion) introduces a rotation component to the radial expanding patterns of visual motion generated in the eyes of moving animals with forward-facing eyes. The resultant image motion (vector flow field) is no longer purely radial, and it is difficult to infer the heading direction from such combined translation-plus-rotation flow fields. The eye need not rotate relative to the head or body during curvilinear self-motion, and so there is an absence of efference signals directing and indicating the rotation...
April 1, 2018: Journal of Vision
Samantha Sze-Yee Lee, Alex A Black, Joanne M Wood
PURPOSE: To assess the link between visual scanning behaviour and closed-road driving performance in older drivers with glaucomatous visual impairment. METHODS: Participants included 13 older drivers with glaucoma (mean age=72.0±6.7▒y; average better-eye mean deviation [MD])=-2.9±2.1▒dB, average worse-eye MD=-12.5±7.1▒dB) and ten visually-normal controls (mean age=70.6±7.4▒y). Visual acuity, contrast sensitivity, visual fields, useful field-of-view (UFoV), and motion sensitivity were assessed...
April 2, 2018: Journal of Glaucoma
Hee Young Lee, Hyun Youk, Jeong Ii Lee, Chan Young Kang, Joon Seok Kong, Sil Sung, In Hye Kang, Jung Hun Lee, Oh Hyun Kim, Woo Jin Jung, Kang Hyun Lee, Young Han Youn, Jong Chan Park
OBJECTIVES: In cases of car-to-person pedestrian traffic crashes (PTCs), the principal issue is determining at what point the car collided with the pedestrian. Accordingly, the objective of the present study was to use the medical records of patients injured in PTCs to investigate the characteristics of crash types and the areas and injury severity and to determine whether there are differences in injuries due to the angle, motion, and position at the point of impact. METHODS: The present study examined 231 PTC patients admitted to the emergency room (ER) between January and December 2014...
February 28, 2018: Traffic Injury Prevention
Christian David Weber, Jana Kristina Schmitz, Christina Garving, Klemens Horst, Hans-Christoph Pape, Frank Hildebrand, Philipp Kobbe
INTRODUCTION: The purpose of this study was to investigate the effects of alcohol intoxication in trauma patients in regard to its impact on application of computed tomography (CT) and associated radiation exposure. METHODS: We conducted a retrospective study from a continuous patient cohort. INCLUSION CRITERIA: admission to the emergency room of an urban Level 1 trauma center with trauma team activation during a 12-month period (Jan 1st-Dec 31st 2012)...
March 22, 2018: European Journal of Trauma and Emergency Surgery: Official Publication of the European Trauma Society
Tsubasa Enosaki, Hideharu Miura, Shintarou Tsuda, Atsushi Kawakubo, Masahiro Hayata, Shuichi Ozawa, Kiyoshi Yamada, Yasushi Nagata
It is important for high-precision radiation therapy that tracking accuracy in dynamic tumor tracking (DTT) using the gimbal X-ray head. We evaluated the tracking accuracy under various respiratory patterns differ from a correlation model [four-dimensional model (4D-model)] in real-time using a digital camera. A sheet of paper with luminous line was placed on the programmable respiratory motion table (CIRS Inc.) and operated with the laser projector. The luminous line was defined as a target and the laser was defined as a gimbal...
2018: Nihon Hoshasen Gijutsu Gakkai Zasshi
Marcie Harris-Hayes, Karen Steger-May, Linda R van Dillen, Mario Schootman, Gretchen B Salsich, Sylvia Czuppon, John C Clohisy, Paul K Commean, Travis J Hillen, Shirley A Sahrmann, Michael J Mueller
Study Design Ancillary analysis, time-controlled randomized clinical trial. Background Movement-pattern training (MPT) has been shown to improve function among patients with chronic hip joint pain (CHJP). Objective To determine the association among treatment outcomes and mechanical factors associated with CHJP. Methods Twenty-eight patients with CHJP, 18 to 40 years of age, participated in MPT, either immediately after assessment or after a wait-list period. Movement-pattern training included task-specific training to reduce hip adduction motion during functional tasks and hip muscle strengthening...
April 2018: Journal of Orthopaedic and Sports Physical Therapy
Rubens Spin-Neto, Louise H Matzen, Lars W Schropp, Thomas S Sørensen, Ann Wenzel
OBJECTIVES: To assess the impact of head motion artefacts and an automated artefact-correction system on cone beam CT (CBCT) image quality and interpretability for simulated diagnostic tasks. METHODS: A partially dentate human skull was mounted on a robot simulating four types of head movement (anteroposterior translation, nodding, lateral rotation, and tremor), at three distances (0.75, 1.5, and 3 mm) based on two movement patterns (skull returning/not returning to the initial position)...
March 22, 2018: Dento Maxillo Facial Radiology
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