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Unnikrishnan G, Ilzhöfer P, Scholz A, Hölzl C, Götzelmann A, Gupta RK, Zhao J, Krauter J, Weber S, Makki N, Büchler HP, Pfau T, Meinert F. Coherent Control of the Fine-Structure Qubit in a Single Alkaline-Earth Atom. Phys Rev Lett 2024; 132:150606. [PMID: 38682979 DOI: 10.1103/physrevlett.132.150606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 03/11/2024] [Indexed: 05/01/2024]
Abstract
We report on the first realization of a novel neutral atom qubit encoded in the spin-orbit coupled metastable states ^{3}P_{0} and ^{3}P_{2} of a single ^{88}Sr atom trapped in an optical tweezer. Raman coupling of the qubit states promises rapid single-qubit rotations on par with the fast Rydberg-mediated two-body gates. We demonstrate preparation, readout, and coherent control of the qubit. In addition to driving Rabi oscillations bridging an energy gap of more than 17 THz using a pair of phase-locked clock lasers, we also carry out Ramsey spectroscopy to extract the transverse qubit coherence time T_{2}. When the tweezer is tuned into magic trapping conditions, which is achieved in our setup by tuning the tensor polarizability of the ^{3}P_{2} state via an external control magnetic field, we measure T_{2}=1.2 ms. A microscopic quantum mechanical model is used to simulate our experiments including dominant noise sources. We identify the main constraints limiting the observed coherence time and project improvements to our system in the immediate future. Our Letter opens the door for a so-far-unexplored qubit encoding concept for neutral atom-based quantum computing.
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Affiliation(s)
- G Unnikrishnan
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - P Ilzhöfer
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - A Scholz
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - C Hölzl
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - A Götzelmann
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - R K Gupta
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - J Zhao
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - J Krauter
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - S Weber
- Institute for Theoretical Physics III and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - N Makki
- Institute for Theoretical Physics III and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - H P Büchler
- Institute for Theoretical Physics III and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Meinert
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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2
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Hertkorn J, Schmidt JN, Guo M, Böttcher F, Ng KSH, Graham SD, Uerlings P, Büchler HP, Langen T, Zwierlein M, Pfau T. Supersolidity in Two-Dimensional Trapped Dipolar Droplet Arrays. Phys Rev Lett 2021; 127:155301. [PMID: 34678009 DOI: 10.1103/physrevlett.127.155301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
We theoretically investigate the ground states and the spectrum of elementary excitations across the superfluid to droplet crystallization transition of an oblate dipolar Bose-Einstein condensate. We systematically identify regimes where spontaneous rotational symmetry breaking leads to the emergence of a supersolid phase with characteristic collective excitations, such as the Higgs amplitude mode. Furthermore, we study the dynamics across the transition and show how these supersolids can be realized with standard protocols in state-of-the-art experiments.
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Affiliation(s)
- J Hertkorn
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - J-N Schmidt
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M Guo
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Böttcher
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - K S H Ng
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - S D Graham
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - P Uerlings
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - H P Büchler
- Institute for Theoretical Physics III and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Langen
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M Zwierlein
- MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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3
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Schmidt JN, Hertkorn J, Guo M, Böttcher F, Schmidt M, Ng KSH, Graham SD, Langen T, Zwierlein M, Pfau T. Roton Excitations in an Oblate Dipolar Quantum Gas. Phys Rev Lett 2021; 126:193002. [PMID: 34047619 DOI: 10.1103/physrevlett.126.193002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 04/02/2021] [Indexed: 06/12/2023]
Abstract
We observe signatures of radial and angular roton excitations around a droplet crystallization transition in dipolar Bose-Einstein condensates. In situ measurements are used to characterize the density fluctuations near this transition. The static structure factor is extracted and used to identify the radial and angular roton excitations by their characteristic symmetries. These fluctuations peak as a function of the interaction strength indicating the crystallization transition of the system. We compare our observations to a theoretically calculated excitation spectrum allowing us to connect the crystallization mechanism with the softening of the angular roton modes.
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Affiliation(s)
- J-N Schmidt
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - J Hertkorn
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M Guo
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Böttcher
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M Schmidt
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - K S H Ng
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - S D Graham
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Langen
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M Zwierlein
- MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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Dieterle T, Berngruber M, Hölzl C, Löw R, Jachymski K, Pfau T, Meinert F. Transport of a Single Cold Ion Immersed in a Bose-Einstein Condensate. Phys Rev Lett 2021; 126:033401. [PMID: 33543963 DOI: 10.1103/physrevlett.126.033401] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 11/12/2020] [Indexed: 06/12/2023]
Abstract
We investigate transport dynamics of a single low-energy ionic impurity in a Bose-Einstein condensate. The impurity is implanted into the condensate starting from a single Rydberg excitation, which is ionized by a sequence of fast electric field pulses aiming to minimize the ion's initial kinetic energy. Using a small electric bias field, we study the subsequent collisional dynamics of the impurity subject to an external force. The fast ion-atom collision rate, stemming from the dense degenerate host gas and the large ion-atom scattering cross section, allow us to study a regime of frequent collisions of the impurity within only tens of microseconds. Comparison of our measurements with stochastic trajectory simulations based on sequential Langevin collisions indicate diffusive transport properties of the impurity and allows us to measure its mobility. Our results open a novel path to study dynamics of charged quantum impurities in ultracold matter.
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Affiliation(s)
- T Dieterle
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M Berngruber
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - C Hölzl
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - R Löw
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - K Jachymski
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Meinert
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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5
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Hertkorn J, Böttcher F, Guo M, Schmidt JN, Langen T, Büchler HP, Pfau T. Fate of the Amplitude Mode in a Trapped Dipolar Supersolid. Phys Rev Lett 2019; 123:193002. [PMID: 31765213 DOI: 10.1103/physrevlett.123.193002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 09/13/2019] [Indexed: 06/10/2023]
Abstract
We theoretically investigate the spectrum of elementary excitations of a trapped dipolar quantum gas across the BEC-supersolid phase transition. Our calculations reveal the existence of distinct Higgs amplitude and Nambu-Goldstone modes that emerge from the softening roton modes of the dipolar BEC at the phase transition point. On the supersolid side of the transition, the energy of the Higgs amplitude mode increases rapidly, leading to a strong coupling to higher-lying modes. Our Letter highlights how the symmetry-breaking nature of the supersolid state translates to finite-size systems.
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Affiliation(s)
- J Hertkorn
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universitt Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Böttcher
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universitt Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M Guo
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universitt Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - J N Schmidt
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universitt Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Langen
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universitt Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - H P Büchler
- Institute for Theoretical Physics III and Center for Integrated Quantum Science and Technology, Universitt Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universitt Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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Engel F, Dieterle T, Hummel F, Fey C, Schmelcher P, Löw R, Pfau T, Meinert F. Precision Spectroscopy of Negative-Ion Resonances in Ultralong-Range Rydberg Molecules. Phys Rev Lett 2019; 123:073003. [PMID: 31491092 DOI: 10.1103/physrevlett.123.073003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Indexed: 06/10/2023]
Abstract
The level structure of negative ions near the electron detachment limit dictates the low-energy scattering of an electron with the parent neutral atom. We demonstrate that a single ultracold atom bound inside a Rydberg orbit forming an ultralong-range Rydberg molecule provides an atomic-scale system that is highly sensitive to electron-neutral scattering and thus allows for detailed insights into the underlying near-threshold anion states. Our measurements reveal the so-far unobserved fine structure of the ^{3}P_{J} triplet of Rb^{-} and allows us to extract parameters of the associated p-wave scattering resonances that deviate from previous theoretical estimates. Moreover, we observe a novel alignment mechanism for Rydberg molecules mediated by spin-orbit coupling in the negative ion.
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Affiliation(s)
- F Engel
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Dieterle
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Hummel
- Zentrum für optische Quantentechnologien, Fachbereich Physik, Universität Hamburg, 22761 Hamburg, Germany
| | - C Fey
- Zentrum für optische Quantentechnologien, Fachbereich Physik, Universität Hamburg, 22761 Hamburg, Germany
| | - P Schmelcher
- Zentrum für optische Quantentechnologien, Fachbereich Physik, Universität Hamburg, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, 22761 Hamburg, Germany
| | - R Löw
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Meinert
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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Maisonpierre IN, Sutton MA, Harris P, Menzies-Gow N, Weller R, Pfau T. Accelerometer activity tracking in horses and the effect of pasture management on time budget. Equine Vet J 2019; 51:840-845. [PMID: 31009100 DOI: 10.1111/evj.13130] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 04/11/2019] [Indexed: 11/27/2022]
Abstract
BACKGROUND Accelerometry is an accepted means of quantifying human physical activity. Quantitative physical activity tracking could be beneficial for studies into equine health and disease prevention, for example in relation to obesity management. OBJECTIVES Validate accelerometer use in grazing horses, determine between-day repeatability, and assess the effects of pasture size on time budget (i.e. duration in each activity category). STUDY DESIGN Proof of concept. METHODS Accelerometers (ActiGraph) were positioned at the poll. Horses underwent 5 min of observed activity in three categories: standing, grazing and ambulating. Receiver-operating characteristic curve analysis, used on ten second data epochs, calculated cut points between the activities. A 20-day study was then undertaken on 6 horses at pasture. Time in each category (per day) was deduced; a Mann Whitney U test was performed to compare standard vs. small paddock and day vs. night turn out. RESULTS Cut-off values with the optimum sensitivity (94.7-97.7%) and specificity (94.7-96.8%) were found to be <127.6 counts for standing, 127.6-702.7 counts for grazing and >702.7 counts for ambulating. Repeatability was analysed descriptively: Median (IQR) of the between-day difference in minutes standing, grazing and ambulating were 46.9 (21.3-87.9), 77.3 (40.2-124.5) and 15.6 (6.8-40.2) respectively. Median times standing and ambulating were significantly different between standard and small paddocks: standing: 8.7 vs. 10.3 h (P<0.001); ambulating: 55.7 vs. 39.6 min (P = 0.002). There was no significant difference in the median time spent grazing. There were significant differences between day and night: standing: 32.95% vs. 50.97% (P = 0.001), grazing: 60.81% vs. 46.77% (P<0.001) and ambulating: 4.57% vs. 2.40% (P<0.001). MAIN LIMITATIONS Small sample size and lack of cross-validation of cut-off points on independent, 'unseen' data. CONCLUSIONS Accelerometry can differentiate standing, grazing and ambulating in horses. Our proof-of-concept study demonstrates modifying pasture size influences activity budgets; opening avenues into studying obesity management.
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Affiliation(s)
- I N Maisonpierre
- Department of Clinical Science and Services, The Royal Veterinary College, Hatfield, UK
| | - M A Sutton
- Department of Clinical Science and Services, The Royal Veterinary College, Hatfield, UK
| | - P Harris
- Mars Horsecare UK Ltd, Equine Studies Group, Waltham Centre for Pet Nutrition, Bury St Edmunds, UK
| | - N Menzies-Gow
- Department of Clinical Science and Services, The Royal Veterinary College, Hatfield, UK
| | - R Weller
- Department of Clinical Science and Services, The Royal Veterinary College, Hatfield, UK
| | - T Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, Hatfield, UK
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Engel F, Dieterle T, Schmid T, Tomschitz C, Veit C, Zuber N, Löw R, Pfau T, Meinert F. Observation of Rydberg Blockade Induced by a Single Ion. Phys Rev Lett 2018; 121:193401. [PMID: 30468597 DOI: 10.1103/physrevlett.121.193401] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Indexed: 06/09/2023]
Abstract
We study the long-range interaction of a single ion with a highly excited ultracold Rydberg atom and report on the direct observation of an ion-induced Rydberg excitation blockade mediated over tens of micrometer distances. Our hybrid ion-atom system is directly produced from an ultracold atomic ensemble via near-threshold photoionization of a single Rydberg excitation, employing a two-photon scheme that is specifically suited for generating a very low-energy ion. The ion's motion is precisely controlled by small electric fields, which allows us to analyze the blockade mechanism for a range of principal quantum numbers. Finally, we explore the capability of the ion as a high-sensitivity, single-atom-based electric field sensor. The observed ion-Rydberg-atom interaction is of current interest for entanglement generation or studies of ultracold chemistry in hybrid ion-atom systems.
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Affiliation(s)
- F Engel
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Dieterle
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Schmid
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - C Tomschitz
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - C Veit
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - N Zuber
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - R Löw
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Meinert
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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9
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Greve L, Pfau T, Dyson S. Alterations in body lean angle in lame horses before and after diagnostic analgesia in straight lines in hand and on the lunge. Vet J 2018; 239:1-6. [PMID: 30197103 DOI: 10.1016/j.tvjl.2018.07.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 05/27/2018] [Accepted: 07/15/2018] [Indexed: 12/18/2022]
Abstract
Altered body lean has been subjectively observed during lungeing in lame horses. The objectives were to quantify the influence of lameness on body lean in trot on the lunge and to investigate the influence of improvement in lameness on the differences in body lean between reins. Thirteen lame horses were trotted in straight lines and lunged on a 10m-diameter circle on both reins before and after lameness was subjectively substantially improved by diagnostic analgesia. A global position system-aided inertial measurement unit attached to the tubera sacrale quantified body lean. Differences between reins in body lean before and after diagnostic analgesia were calculated and means were determined. Five and eight horses had unilateral and bilateral hindlimb lameness, respectively. Two of five horses with unilateral and three of eight horses with bilateral lameness leaned more on the rein with the lame or lamer hindlimb on the inside of the circle (difference between reins 5-8°). Two of five horses with unilateral and two of eight horses with bilateral lameness leaned more on the rein with the lame or lamer hindlimb on the outside of the circle (4-10°). Four horses, one with unilateral and three with bilateral lameness, had only 1° difference in body lean angle between left and right reins. When lameness was improved by diagnostic analgesia, the body lean changed significantly towards similar leaning on left and right reins (mean angle changed from 8.8° to 10.0° (P=0.03) on one rein and 13.4° to 10.8° (P=0.002) on the other rein). It was concluded that body lean becomes more symmetrical between reins after improvement in lameness using diagnostic analgesia.
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Affiliation(s)
- L Greve
- Centre for Equine Studies, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK; Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK.
| | - T Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK
| | - S Dyson
- Centre for Equine Studies, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK
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10
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Affiliation(s)
- R Weller
- Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - A Barstow
- Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - H Price
- Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - T Pfau
- Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield, Hertfordshire, UK
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11
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van Weeren PR, Pfau T, Rhodin M, Roepstorff L, Serra Bragança F, Weishaupt MA. What is lameness and what (or who) is the gold standard to detect it? Equine Vet J 2018; 50:549-551. [PMID: 29953639 DOI: 10.1111/evj.12970] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- P R van Weeren
- Department of Equine Sciences, Utrecht University, Utrecht, the Netherlands
| | - T Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hatfield, UK
| | - M Rhodin
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - L Roepstorff
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - F Serra Bragança
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hatfield, UK
| | - M A Weishaupt
- Equine Department, University of Zurich, Zurich, Switzerland
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12
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Rhodin M, Persson-Sjodin E, Egenvall A, Serra Bragança FM, Pfau T, Roepstorff L, Weishaupt MA, Thomsen MH, van Weeren PR, Hernlund E. Vertical movement symmetry of the withers in horses with induced forelimb and hindlimb lameness at trot. Equine Vet J 2018; 50:818-824. [PMID: 29658147 PMCID: PMC6175082 DOI: 10.1111/evj.12844] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Accepted: 03/30/2018] [Indexed: 12/01/2022]
Abstract
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. Objectives To investigate the association between head, withers and pelvis movement asymmetry in horses with induced forelimb and hindlimb lameness. Study design Experimental study. Methods In 10 clinically sound Warmblood riding horses, forelimb and hindlimb lameness were induced using a sole pressure model. The horses were then trotted on a treadmill. Three‐dimensional optical motion capture was used to collect kinematic data from reflective markers attached to the poll, withers and tubera sacrale. The magnitude and side (left or right) of the following symmetry parameters, vertical difference in minimum position, maximum position and range‐up were calculated for head, withers, and pelvis. Mixed models were used to analyse data from induced forelimb and hindlimb lameness. Results For each mm increase in pelvic asymmetry in response to hindlimb lameness induction, withers movement asymmetry increased by 0.35–0.55 mm, but towards the contralateral side. In induced forelimb lameness, for each mm increase in head movement asymmetry, withers movement asymmetry increased by 0.05–0.10 mm, in agreement with the head movement asymmetry direction, both indicating lameness in the induced forelimb. Main limitations Results must be confirmed in clinically lame horses trotting overground. Conclusions The vertical asymmetry pattern of the withers discriminated a head nod associated with true forelimb lameness from the compensatory head movement asymmetry caused by primary hindlimb lameness. Measuring movement symmetry of the withers may, thus, aid in determining primary lameness location.
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Affiliation(s)
- M Rhodin
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - E Persson-Sjodin
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - A Egenvall
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - F M Serra Bragança
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - T Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, North Mymms, Hatfield, Hertfordshire, UK
| | - L Roepstorff
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - M A Weishaupt
- Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - M H Thomsen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark
| | - P R van Weeren
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - E Hernlund
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
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13
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Barstow A, Bailey J, Campbell J, Harris C, Weller R, Pfau T. Does 'hacking' surface type affect equine forelimb foot placement, movement symmetry or hoof impact deceleration during ridden walk and trot exercise? Equine Vet J 2018; 51:108-114. [PMID: 29665054 DOI: 10.1111/evj.12952] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 03/31/2018] [Indexed: 11/30/2022]
Abstract
BACKGROUND Both pleasure and competition horses regularly exercise on surfaces such as tarmac, gravel and turf during 'hacking'. Despite this, there is limited evidence relating to the effect of these surfaces upon foot-surface interaction. OBJECTIVES To investigate forelimb foot placement, hoof vibration and movement symmetry in pleasure horses on three commonly encountered hacking surfaces. STUDY DESIGN Quantitative gait study in a convenience sample. METHODS Six horses regularly partaking in hacking exercise were ridden in walk and trot on all surfaces. Horses were equipped with one hoof-mounted, accelerometer and four body-mounted inertial measurement units (IMUs) to measure foot impact and movement symmetry. High-speed (400 FPS) video footage of foot-placement was acquired (dorsal, palmar, lateral views). Foot-impact and movement symmetry were analysed with a mixed effects model and Bowker symmetry tests for foot-placement analysis. RESULTS Vibration power and frequency parameters increase as perceived surface firmness increases from grass, to gravel, to tarmac (P≤0.001). Vibration power parameters were consistently greater at trot compared with walk (P≤0.001), but the same was not true for vibration frequency (P≥0.2). Greatest movement asymmetry was recorded during grass surface trotting. No significant difference in foot-placement was detected between the three surfaces. MAIN LIMITATIONS This was a field study using three commonly encountered hacking surfaces. Surface properties change easily with water content and temperature fluctuations so care must be taken when considering other similar surfaces, especially at different times of the year. Six leisure horses were used so the results may not be representative of horses of all types. CONCLUSIONS Vibration parameters generally increase as perceived surface firmness increases. Increasing speed alters vibration power but not frequency. Further investigations are required to determine the role that this may play in the development of musculoskeletal disease in horses.
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Affiliation(s)
- A Barstow
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, UK.,Structure and Motion Laboratory, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - J Bailey
- Structure and Motion Laboratory, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - J Campbell
- Structure and Motion Laboratory, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - C Harris
- Structure and Motion Laboratory, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - R Weller
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, UK.,Structure and Motion Laboratory, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - T Pfau
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, UK.,Structure and Motion Laboratory, Royal Veterinary College, Hatfield, Hertfordshire, UK
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Kleinbach KS, Engel F, Dieterle T, Löw R, Pfau T, Meinert F. Ionic Impurity in a Bose-Einstein Condensate at Submicrokelvin Temperatures. Phys Rev Lett 2018; 120:193401. [PMID: 29799221 DOI: 10.1103/physrevlett.120.193401] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Indexed: 06/08/2023]
Abstract
Rydberg atoms immersed in a Bose-Einstein condensate interact with the quantum gas via electron-atom and ion-atom interaction. To suppress the typically dominant electron-neutral interaction, Rydberg states with a principal quantum number up to n=190 are excited from a dense and tightly trapped micron-sized condensate. This allows us to explore a regime where the Rydberg orbit exceeds the size of the atomic sample by far. In this case, a detailed line shape analysis of the Rydberg excitation spectrum provides clear evidence for ion-atom interaction at temperatures well below a microkelvin. Our results may open up ways to enter the quantum regime of ion-atom scattering for the exploration of charged quantum impurities and associated polaron physics.
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Affiliation(s)
- K S Kleinbach
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Engel
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Dieterle
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - R Löw
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Meinert
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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15
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Serra Bragança FM, Rhodin M, Wiestner T, Hernlund E, Pfau T, van Weeren P, Weishaupt MA. Quantification of the effect of instrumentation error in objective gait assessment in the horse on hindlimb symmetry parameters. Equine Vet J 2018; 50:370-376. [PMID: 29032614 PMCID: PMC5900976 DOI: 10.1111/evj.12766] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 10/10/2017] [Indexed: 11/27/2022]
Abstract
BACKGROUND Objective gait analysis is becoming more popular as a tool assisting veterinarians during the clinical lameness exam. At present, there is only limited information on the effect of misplacement of markers/motion-sensors. OBJECTIVES To investigate and describe the effect of marker misplacement on commonly calculated pelvic symmetry parameters. STUDY DESIGN Experimental study. METHODS Each horse was equipped with custom-made devices consisting of several reflective markers arranged in a predefined manner with a reference marker correctly positioned regarding the anatomical landmark and several misplaced markers along the sagittal and transverse planes. Linear regression analysis was used to estimate the effect of marker misplacement. RESULTS For the tubera sacrale, each cm of left/right misplacement led to a difference in minimum position of the pelvis (PDmin) of ±1.67 mm (95% CI 1.54-1.8 mm) (P<0.001); maximum position of the pelvis (PDmax) was affected by ±0.2 mm (95% CI 0.071-0.33 mm) (P = 0.003). With respect to cranial/caudal misplacement, each cm of misplacement resulted in a PDmin difference of ±0.04 mm (95% CI -0.09 to 0.16 mm) (P = 0.56) and a PDmax difference of ±0.008 mm (95% CI -0.13 to 0.12 mm) (P = 0.9). For the tubera coxae, each cm of vertical misplacement led to a difference in the displacement amplitude between left and right tubera coxae (Hip-Hike_Diff) of ±1.56 mm (95% CI 1.35-1.77 mm) (P<0.001); for the cranial/caudal misplacement, this was ±0.82 mm (95% CI 0.66-0.97 mm) (P<0.001). MAIN LIMITATIONS Only three horses were used in this experiment and the study design did not permit to determine the influence of marker misplacement on the evaluation of different degrees of lameness. CONCLUSIONS Marker misplacement significantly affects calculated symmetry parameters of the pelvis. The observed errors are overall small but significant. In cases of mildly asymmetrical horses, this error might influence the decision-making process whereas in more severe asymmetries, the influence of the error effect may become less significant.
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Affiliation(s)
- F. M. Serra Bragança
- Department of Equine SciencesFaculty of Veterinary MedicineUtrecht UniversityUtrechtThe Netherlands
| | - M. Rhodin
- Department of Clinical SciencesSwedish University of Agricultural SciencesUppsalaSweden
| | - T. Wiestner
- Equine DepartmentVetsuisse Faculty University of ZurichZurichSwitzerland
| | - E. Hernlund
- Department of Clinical SciencesSwedish University of Agricultural SciencesUppsalaSweden
| | - T. Pfau
- Department of Clinical Science and ServicesThe Royal Veterinary CollegeHatfieldHertfordshireUK
| | - P.R. van Weeren
- Department of Equine SciencesFaculty of Veterinary MedicineUtrecht UniversityUtrechtThe Netherlands
| | - M. A. Weishaupt
- Equine DepartmentVetsuisse Faculty University of ZurichZurichSwitzerland
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16
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Schmid T, Veit C, Zuber N, Löw R, Pfau T, Tarana M, Tomza M. Rydberg Molecules for Ion-Atom Scattering in the Ultracold Regime. Phys Rev Lett 2018; 120:153401. [PMID: 29756888 DOI: 10.1103/physrevlett.120.153401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Indexed: 06/08/2023]
Abstract
We propose a novel experimental method to extend the investigation of ion-atom collisions from the so far studied cold, essentially classical regime to the ultracold, quantum regime. The key aspect of this method is the use of Rydberg molecules to initialize the ultracold ion-atom scattering event. We exemplify the proposed method with the lithium ion-atom system, for which we present simulations of how the initial Rydberg molecule wave function, freed by photoionization, evolves in the presence of the ion-atom scattering potential. We predict bounds for the ion-atom scattering length from ab initio calculations of the interaction potential. We demonstrate that, in the predicted bounds, the scattering length can be experimentally determined from the velocity of the scattered wave packet in the case of ^{6}Li^{+}-^{6}Li and from the molecular ion fraction in the case of ^{7}Li^{+}-^{7}Li. The proposed method to utilize Rydberg molecules for ultracold ion-atom scattering, here particularized for the lithium ion-atom system, is readily applicable to other ion-atom systems as well.
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Affiliation(s)
- T Schmid
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - C Veit
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - N Zuber
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - R Löw
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M Tarana
- J. Heyrovský Institute of Physical Chemistry of the ASCR, v.v.i., Dolejškova 2155/3, 182 23 Prague 8, Czech Republic
| | - M Tomza
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
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Pfau T, Sepulveda Caviedes MF, McCarthy R, Cheetham L, Forbes B, Rhodin M. Comparison of visual lameness scores to gait asymmetry in racing Thoroughbreds during trot in‐hand. EQUINE VET EDUC 2018. [DOI: 10.1111/eve.12914] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- T. Pfau
- Department of Clinical Science and Services The Royal Veterinary CollegeHatfield Hertfordshire UK
- Structure and Motion Lab The Royal Veterinary College Hatfield Hertfordshire UK
| | - M. F. Sepulveda Caviedes
- Department of Clinical Science and Services The Royal Veterinary CollegeHatfield Hertfordshire UK
- Structure and Motion Lab The Royal Veterinary College Hatfield Hertfordshire UK
| | - R. McCarthy
- Department of Clinical Science and Services The Royal Veterinary CollegeHatfield Hertfordshire UK
| | - L. Cheetham
- Department of Clinical Science and Services The Royal Veterinary CollegeHatfield Hertfordshire UK
| | - B. Forbes
- Singapore Turf Club SingaporeSingapore
| | - M. Rhodin
- Department of Anatomy, Physiology and Biochemistry Swedish University of Agricultural Sciences Uppsala Sweden
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18
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Zhang H, Zhu B, Park S, Doerr C, Aydinlik M, Geyer J, Pfau T, Pendock G, Aroca R, Liu F, Rasmussen C, Mikkelsen B, Borel PI, Geisler T, Jensen R, Peckham DW, Lingle R, Vaidya D, Yan MF, Wisk PW, DiGiovanni DJ. Real-time transmission of 16 Tb/s over 1020km using 200Gb/s CFP2-DCO. Opt Express 2018; 26:6943-6948. [PMID: 29609380 DOI: 10.1364/oe.26.006943] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 03/01/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate real-time transmission of 16 Tb/s (80x200Gb/s) over 1020km TeraWave ULL fiber with 170km span length using the world's first 200Gb/s CFP2-DCO module with a record low power consumption less than 0.1W/Gbps.
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19
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Sepulveda Caviedes MF, Forbes BS, Pfau T. Repeatability of gait analysis measurements in Thoroughbreds in training. Equine Vet J 2018; 50:513-518. [PMID: 29284186 DOI: 10.1111/evj.12802] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 12/19/2017] [Indexed: 11/29/2022]
Abstract
BACKGROUND With the view of implementing gait symmetry measurements in Thoroughbreds in training for early detection of injuries, repeatability of inertial measurement unit (IMU) gait parameters needs to be established. OBJECTIVES To assess the variation of head and pelvis movement symmetry in Thoroughbreds in training. STUDY DESIGN Repeated observations in horses in race training. METHODS Daily and weekly repeat gait assessments were conducted in 14 Thoroughbreds equipped with IMUs on poll, sacrum and right (RTC) and left (LTC) tuber coxae. Gait was assessed in trot, in-hand, on a level concrete surface. Difference between vertical displacement minima and maxima and range of motion (ROM) were obtained. Ranges containing 50% (median), 75, 90 and 95% of absolute daily and weekly differences were calculated and intraclass correlation coefficients (ICC) calculated for daily and weekly repeats. RESULTS Median absolute daily differences ranged from 4 to 7 mm and median weekly differences from 4 to 8 mm. 90% of daily differences were between 9 and 16 mm and 90% of weekly differences between 11 and 19 mm. ICC values were found on average across sensors and gait parameters as 0.73 (ranging from 0.40 to 0.92 across parameters) for daily repeats and as 0.65 (0.27 to 0.91) for weekly repeats. MAIN LIMITATIONS Horses were of varying training and movement asymmetry levels, and no veterinary lameness examination was conducted. CONCLUSIONS Daily and weekly repeat gait assessments in this group of Thoroughbreds in training show lower ICC values than previously reported from within-day repeats in horses during lameness examinations. We recommend conducting repeatability studies for specific groups of horses when planning long-term studies aiming at identifying horses at risk of injury.
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Affiliation(s)
- M F Sepulveda Caviedes
- Department of Clinical Science and Services and Structure and Motion Lab, The Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - B S Forbes
- Singapore Turf Club, Singapore, Singapore
| | - T Pfau
- Department of Clinical Science and Services and Structure and Motion Lab, The Royal Veterinary College, Hatfield, Hertfordshire, UK
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20
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Pfau T, Noordwijk K, Sepulveda Caviedes MF, Persson‐Sjodin E, Barstow A, Forbes B, Rhodin M. Head, withers and pelvic movement asymmetry and their relative timing in trot in racing Thoroughbreds in training. Equine Vet J 2018; 50:117-124. [PMID: 28548349 PMCID: PMC5724686 DOI: 10.1111/evj.12705] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 05/16/2017] [Indexed: 11/27/2022]
Abstract
BACKGROUND Horses show compensatory head movement in hindlimb lameness and compensatory pelvis movement in forelimb lameness but little is known about the relationship of withers movement symmetry with head and pelvic asymmetry in horses with naturally occurring gait asymmetries. OBJECTIVES To document head, withers and pelvic movement asymmetry and timing differences in horses with naturally occurring gait asymmetries. STUDY DESIGN Retrospective analysis of gait data. METHODS Head, withers and pelvic movement asymmetry and timing of displacement minima and maxima were quantified from inertial sensors in 163 Thoroughbreds during trot-ups on hard ground. Horses were divided into 4 subgroups using the direction of head and withers movement asymmetry. Scatter plots of head vs. pelvic movement asymmetry illustrated how the head-withers relationship distinguishes between contralateral and ipsilateral head-pelvic movement asymmetry. Independent t test or Mann-Whitney U test (P<0.05) compared pelvic movement asymmetry and timing differences between groups. RESULTS The relationship between head and withers asymmetry (i.e. same sided or opposite sided asymmetry) predicts the relationship between head and pelvic asymmetry in 69-77% of horses. Pelvic movement symmetry was significantly different between horses with same sign vs. opposite sign of head-withers asymmetry (P<0.0001). Timing of the maximum head height reached after contralateral ('sound') stance was delayed compared to withers (P = 0.02) and pelvis (P = 0.04) in horses with contralateral head-withers asymmetry. MAIN LIMITATIONS The clinical lameness status of the horses was not investigated. CONCLUSION In the Thoroughbreds with natural gait asymmetries investigated here, the direction of head vs. withers movement asymmetry identifies the majority of horses with ipsilateral and contralateral head and pelvic movement asymmetries. Withers movement should be further investigated for differentiating between forelimb and hindlimb lame horses. Horses with opposite sided head and withers asymmetry significantly delay the upward movement of the head after 'sound' forelimb stance.
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Affiliation(s)
- T. Pfau
- Department of Clinical Science and ServicesRoyal Veterinary CollegeLondonUK
- Structure and Motion LaboratoryRoyal Veterinary CollegeLondonUK
| | - K. Noordwijk
- Structure and Motion LaboratoryRoyal Veterinary CollegeLondonUK
| | - M. F. Sepulveda Caviedes
- Department of Clinical Science and ServicesRoyal Veterinary CollegeLondonUK
- Structure and Motion LaboratoryRoyal Veterinary CollegeLondonUK
| | - E. Persson‐Sjodin
- Department of Clinical SciencesSwedish University of Agricultural SciencesUppsalaSweden
| | - A. Barstow
- Department of Clinical Science and ServicesRoyal Veterinary CollegeLondonUK
- Structure and Motion LaboratoryRoyal Veterinary CollegeLondonUK
| | - B. Forbes
- Singapore Turf ClubSingaporeSingapore
| | - M. Rhodin
- Department of Clinical SciencesSwedish University of Agricultural SciencesUppsalaSweden
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21
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Olsen E, FouchÉ N, Jordan H, Pfau T, Piercy RJ. Kinematic discrimination of ataxia in horses is facilitated by blindfolding. Equine Vet J 2017; 50:166-171. [DOI: 10.1111/evj.12737] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 08/05/2017] [Indexed: 11/27/2022]
Affiliation(s)
- E. Olsen
- Structure and Motion Laboratory The Royal Veterinary College London UK
- Cornell University College of Veterinary Medicine Ithaca New York USA
| | - N. FouchÉ
- Swiss Institute of Equine Medicine (ISME) Vetsuisse‐Faculty University of Bern and Agroscope Berne Switzerland
| | - H. Jordan
- Structure and Motion Laboratory The Royal Veterinary College London UK
| | - T. Pfau
- Structure and Motion Laboratory The Royal Veterinary College London UK
| | - R. J. Piercy
- Department of Clinical Sciences and Services The Royal Veterinary College London UK
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22
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Weeren PR, Pfau T, Rhodin M, Roepstorff L, Serra Bragança F, Weishaupt MA. Do we have to redefine lameness in the era of quantitative gait analysis? Equine Vet J 2017; 49:567-569. [DOI: 10.1111/evj.12715] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- P. R. Weeren
- Department of Equine Sciences Utrecht University Utrecht the Netherlands
| | - T. Pfau
- Department of Clinical Science and Services The Royal Veterinary College University of London Hatfield UK
| | - M. Rhodin
- Department of Clinical Sciences Swedish University of Agricultural Sciences Uppsala Sweden
| | - L. Roepstorff
- Department of Clinical Sciences Swedish University of Agricultural Sciences Uppsala Sweden
| | - F. Serra Bragança
- Department of Equine Sciences Utrecht University Utrecht the Netherlands
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23
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Pfau T, Simons V, Rombach N, Stubbs N, Weller R. Effect of a 4-week elastic resistance band training regimen on back kinematics in horses trotting in-hand and on the lunge. Equine Vet J 2017; 49:829-835. [DOI: 10.1111/evj.12690] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 04/16/2017] [Indexed: 11/30/2022]
Affiliation(s)
- T. Pfau
- Department of Clinical Science and Services; Royal Veterinary College; London UK
- Structure and Motion Lab; Royal Veterinary College; London UK
| | - V. Simons
- Department of Clinical Science and Services; Royal Veterinary College; London UK
| | | | - N. Stubbs
- Department of Equine Sports Medicine; Tierklinik Lüsche; Germany and Samorin, Napoli Slovak Equestrian Club Ślovak
| | - R. Weller
- Department of Clinical Science and Services; Royal Veterinary College; London UK
- Structure and Motion Lab; Royal Veterinary College; London UK
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Greve L, Dyson S, Pfau T. Alterations in thoracolumbosacral movement when pain causing lameness has been improved by diagnostic analgesia. Vet J 2017; 224:55-63. [PMID: 28697877 DOI: 10.1016/j.tvjl.2017.03.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Revised: 03/21/2017] [Accepted: 03/30/2017] [Indexed: 10/19/2022]
Abstract
Lameness, thoracolumbosacral pain and reduced range of motion (ROM) often coexist; better understanding of their relationship is needed. The objectives were to determine if thoracolumbosacral movement of horses changes when pain causing lameness is improved by diagnostic analgesia. We hypothesised that reduction of lameness will increase ROM of the thoracolumbosacral region. Thirteen horses with different types of hind limb lameness were trotted in straight lines and lunged on a 10m diameter circle on left and right reins before and after lameness was subjectively substantially improved by diagnostic analgesia. Inertial sensor data were collected from the withers, thirteenth (T13) and eighteenth thoracic (T18) vertebrae, third lumbar (L3) vertebra, tubera sacrale (TS), left and right tubera coxae. ROM of flexion-extension, axial rotation, lateral bending, dorsoventral, lateral-lateral motion and vertical movement symmetry were quantified at each thoracolumbar site. Hiphike difference (HHD), maximum difference (MaxDiff) and minimum difference (MinDiff) for the pelvic sensors were measured. Percentage changes for before and after diagnostic analgesia were calculated; mean±standard deviation (SD) or median [interquartile range] were determined. Associations between the change in pelvic versus thoracolumbar movement symmetry after each local analgesic technique were tested. After resolution of lameness, HHD decreased by 7% [68%] (P=0.006). The MinDiff decreased significantly by 33% [61%] (P=0.01), 45±13% (P=0.005) and 52±23% (P=0.04), for TS, L3 and T18, respectively. There was significantly increased ROM in flexion-extension at T13, in axial rotation at T13, T18, L3 and in lateral-lateral ROM at L3. Thoracolumbosacral asymmetry and reduced ROM associated with lameness were both altered immediately by improvement in lameness using diagnostic analgesia.
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Affiliation(s)
- L Greve
- Centre for Equine Studies, Animal Health Trust,Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK; Department of Clinical Science and Services, The Royal Veterinary College, University of London,Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK.
| | - S Dyson
- Centre for Equine Studies, Animal Health Trust,Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK
| | - T Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, University of London,Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK
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Greve L, Pfau T, Dyson S. Thoracolumbar movement in sound horses trotting in straight lines in hand and on the lunge and the relationship with hind limb symmetry or asymmetry. Vet J 2017; 220:95-104. [PMID: 28190505 DOI: 10.1016/j.tvjl.2017.01.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 01/02/2017] [Accepted: 01/03/2017] [Indexed: 10/20/2022]
Abstract
Equine movement symmetry is changed when turning, which may induce alterations in thoracolumbosacral kinematics; however, this has not previously been investigated. Our objectives were to document thoracolumbar movement in subjectively sound horses comparing straight lines with circles on both reins and to relate these observations to the objectively determined symmetry/asymmetry of hindlimb gait. Fourteen non-lame horses were assessed prospectively in a non-random, cross-sectional survey. The horses were trotted in straight lines and lunged on both reins and inertial sensor data collected at landmarks: withers, T13 and T18, L3, tubera sacrale, and left and right tubera coxae. Data were processed using published methods; angular motion range of motion (ROM; flexion-extension, axial rotation, lateral bending) and translational ROM (dorsoventral and lateral) and symmetry within each stride were assessed. The dorsoventral movement of the back exhibited a sinusoidal pattern with two oscillations per stride. Circles induced greater asymmetry in dorsoventral movement within each stride (mean ± standard deviation, up to 9 ± 6%) compared with straight lines (up to 6 ± 6%). The greatest amplitude of dorsoventral movement (119 ± 14 mm in straight lines vs. 126 ± 20 mm in circles) occurred at T13. Circles induced greater flexion-extension ROM (>1.3°; P = 0.002), lateral bending (>16°; P <0.001), and lateral motion (>16 mm; P = 0.002) compared with straight lines. Circles induced a movement pattern similar to an inside hindlimb lameness, which was significantly associated with the circle-induced greater asymmetry of dorsoventral movement of the thoracolumbar region (P = 0.03). Moving in a circle induces measurable changes in thoracolumbar movement compared with moving in straight lines, associated with alterations in the hindlimb gait.
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Affiliation(s)
- L Greve
- Centre for Equine Studies, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK; Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK.
| | - T Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK
| | - S Dyson
- Centre for Equine Studies, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK
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Walker AM, Martin A, Pfau T, Sparkes EL, Wilson AM, Witte TH. How realistic is a racehorse simulator? J Biomech 2016; 49:3570-3575. [PMID: 27594678 DOI: 10.1016/j.jbiomech.2016.08.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 07/28/2016] [Accepted: 08/23/2016] [Indexed: 10/21/2022]
Abstract
Race jockey training is demanding and technical. Increased horse care costs and demands on time have led to greater availability and use of racehorse simulators during training. Little is known about the accuracy of the simulated movement and therefore how effective they are for developing the desired technique. We quantified and compared sacral rotation and displacement vectors for a racehorse simulator and a real galloping horse. A single inertial measurement unit was placed on the sacrum of six horses (horse) during a training gallop along an all-weather seven furlong gallop and on the highest speed setting 'four' on the simulator. Displacements were calculated in all three axes before being cut into cycles and analysed along with roll and pitch. Displacement and rotation amplitudes were extracted and compared for the horse and simulator. Horse sacral movement parameters were more varied than those recorded on the simulator. The real horse exhibited greater dorso-ventral, medio-lateral and roll amplitude but smaller cranio-caudal displacement amplitude and no difference in pitch amplitude. Displacement trajectory of the simulator when viewed laterally from the left side, was anticlockwise, the opposite direction to that of the real horse leaving the regular use of a simulator during jockey training under question. Use of the racehorse simulator is beneficial to develop specific fitness and to enable physical manipulation into the optimal position. Care must be taken to avoid any detrimental effects of training with the opposite movement trajectory to that experienced during a race. The programming of the simulators may benefit from adaptations to maximise their benefits.
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Affiliation(s)
- A M Walker
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, United Kingdom.
| | - A Martin
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, United Kingdom
| | - T Pfau
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, United Kingdom
| | - E L Sparkes
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, United Kingdom
| | - A M Wilson
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, United Kingdom
| | - T H Witte
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, United Kingdom
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Walker AM, Applegate C, Pfau T, Sparkes EL, Wilson AM, Witte TH. The kinematics and kinetics of riding a racehorse: A quantitative comparison of a training simulator and real horses. J Biomech 2016; 49:3368-3374. [PMID: 27622974 DOI: 10.1016/j.jbiomech.2016.08.031] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 07/28/2016] [Accepted: 08/23/2016] [Indexed: 10/21/2022]
Abstract
Movement of a racehorse simulator differs to that of a real horse, but the effects of these differences on jockey technique have not been evaluated. We quantified and compared the kinematics and kinetics of jockeys during gallop riding on a simulator and real horses. Inertial measurement units were attached mid-shaft to the long bones of six jockeys and the sacrum of the horse or simulator. Instrumented stirrups were used to measure force. Data were collected during galloping on a synthetic gallop or while riding a racehorse simulator. Jockey kinematics varied more on a real horse compared to the simulator. Greater than double the peak stirrup force was recorded during gallop on real horses compared to the simulator. On the simulator stirrup forces were symmetrical, whereas on a real horse peak forces were higher on the opposite side to the lead limb. Asymmetric forces and lateral movement of the horse and jockey occurs away from the side of the lead leg, likely a result of horse trunk roll. Jockeys maintained a more upright trunk position on a real horse compared to simulator, with no change in pitch. The feet move in phase with the horse and simulator exhibiting similar magnitude displacements in all directions. In contrast the pelvis was in phase with the horse and simulator in the dorso-ventral and medio-lateral axes while a phase shift of 180° was seen in the cranio-caudal direction indicating an inverted pendulum action of the jockey.
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Affiliation(s)
- A M Walker
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, United Kingdom.
| | - C Applegate
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, United Kingdom
| | - T Pfau
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, United Kingdom
| | - E L Sparkes
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, United Kingdom
| | - A M Wilson
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, United Kingdom
| | - T H Witte
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, United Kingdom
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Pfau T, Daly K, Davison J, Bould A, Housby N, Weller R. Changes in movement symmetry over the stages of the shoeing process in military working horses. Vet Rec 2016; 179:195. [DOI: 10.1136/vr.103516] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/27/2016] [Indexed: 11/04/2022]
Affiliation(s)
- T. Pfau
- Department of Clinical Science and Services; The Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Herts AL9 7TA UK
| | - K. Daly
- Department of Clinical Science and Services; The Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Herts AL9 7TA UK
| | - J. Davison
- Department of Clinical Science and Services; The Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Herts AL9 7TA UK
| | - A. Bould
- The King's Troop, Royal Horse Artillery; Woolwich London UK
| | - N. Housby
- The King's Troop, Royal Horse Artillery; Woolwich London UK
| | - R. Weller
- Department of Clinical Science and Services; The Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Herts AL9 7TA UK
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Pfau T, Weller R. Comparison of a standalone consumer grade smartphone with a specialist inertial measurement unit for quantification of movement symmetry in the trotting horse. Equine Vet J 2015; 49:124-129. [PMID: 26518143 DOI: 10.1111/evj.12529] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 10/17/2015] [Indexed: 11/30/2022]
Abstract
REASONS FOR PERFORMING STUDY Equine inertial measurement unit (IMU) gait analysis has gained in popularity for use in horses. Similar transducers are now found in consumer grade smartphones. However, to date there are no scientific data evaluating their use for assessment of movement (a)symmetry in the horse. OBJECTIVES To establish limits of agreement (LoA, mean difference ±2 s.d.) between a validated specialist IMU system and IMU data collected with a consumer grade smartphone for quantification of movement symmetry and range of motion (ROM) of pelvic movement in the trotting horse. STUDY DESIGN Method comparison study based on quantitative gait data. METHODS Twenty horses were equipped with a specialist IMU (MTw, Xsens) and a consumer grade smartphone (Apple iPhone6), both securely attached immediately in front of one another in the midline over the sacrum. Horses were trotted in-hand and lunged on both reins on a soft arena surface. Median values for movement symmetry and ROM were determined over a series of strides for each exercise condition. Data collection was repeated in 6 horses to determine the effect of mediolateral sensor positioning on outcome parameters. RESULTS Valid data from 17 horses resulted in LoA values of -3.7 ± 9.2 mm for MinDiff (difference between left and right hind mid stance), -0.6 ± 6.0 mm for MaxDiff (difference between left and right hind propulsion) and -0.8 ± 7.4 mm for ROM across horses and exercises. LoAs were narrower for straight line exercise and the negative bias was considerably reduced when moving the smartphone to the right of the midline. CONCLUSIONS The consumer grade smartphone provided meaningful gait data in horses: LoAs in particular for in-hand exercise and when adjusting the mediolateral positioning are similar to published asymmetry thresholds. Owing to the sensitivity to mediolateral positioning, particular care should be taken when placing an IMU over the midline of the horse.
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Affiliation(s)
- T Pfau
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, UK
| | - R Weller
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, UK
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Maier T, Kadau H, Schmitt M, Wenzel M, Ferrier-Barbut I, Pfau T, Frisch A, Baier S, Aikawa K, Chomaz L, Mark MJ, Ferlaino F, Makrides C, Tiesinga E, Petrov A, Kotochigova S. Emergence of Chaotic Scattering in Ultracold Er and Dy. Phys Rev X 2015; 5:041029. [PMID: 29876143 PMCID: PMC5986194 DOI: 10.1103/physrevx.5.041029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We show that for ultracold magnetic lanthanide atoms chaotic scattering emerges due to a combination of anisotropic interaction potentials and Zeeman coupling under an external magnetic field. This scattering is studied in a collaborative experimental and theoretical effort for both dysprosium and erbium. We present extensive atom-loss measurements of their dense magnetic Feshbach-resonance spectra, analyze their statistical properties, and compare to predictions from a random-matrix-theory-inspired model. Furthermore, theoretical coupled-channels simulations of the anisotropic molecular Hamiltonian at zero magnetic field show that weakly bound, near threshold diatomic levels form overlapping, uncoupled chaotic series that when combined are randomly distributed. The Zeeman interaction shifts and couples these levels, leading to a Feshbach spectrum of zero-energy bound states with nearest-neighbor spacings that changes from randomly to chaotically distributed for increasing magnetic field. Finally, we show that the extreme temperature sensitivity of a small, but sizable fraction of the resonances in the Dy and Er atom-loss spectra is due to resonant nonzero partial-wave collisions. Our threshold analysis for these resonances indicates a large collision-energy dependence of the three-body recombination rate.
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Affiliation(s)
- T. Maier
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - H. Kadau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M. Schmitt
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M. Wenzel
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - I. Ferrier-Barbut
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T. Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - A. Frisch
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - S. Baier
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - K. Aikawa
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - L. Chomaz
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - M. J. Mark
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - F. Ferlaino
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - C. Makrides
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - E. Tiesinga
- Joint Quantum Institute and Center for Quantum Information and Computer Science, National Institute of Standards and Technology and the University of Maryland, 100 Bureau Drive, Stop 8423, Gaithersburg, Maryland 20899, USA
| | - A. Petrov
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - S. Kotochigova
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
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Simons V, Weller R, Stubbs NC, Rombach N, Pfau T. Clinical Research Abstracts of the British Equine Veterinary Association Congress 2015. Equine Vet J 2015; 47 Suppl 48:11. [PMID: 26375722 DOI: 10.1111/evj.12486_23] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
REASONS FOR PERFORMING STUDY Training and rehabilitation techniques which improve core muscle strength are beneficial for improvement of dynamic stability of the equine vertebral column. The Equiband™ system, consisting of resistance bands attached to a customised saddle pad, is suggested to provide constant proprioceptive feedback during motion to encourage recruitment of abdominal and hindquarter musculature. OBJECTIVES To quantify the effect of the Equiband™ system on back kinematics and movement symmetry. STUDY DESIGN Longitudinal intervention study. METHODS Quantitative analysis of back movement and gait symmetry before/after a 4-week exercise programme. Inertial sensor data was collected from 7 horses at Weeks 0 and 4 of a fixed exercise protocol. Analysis with and without the Equiband™ system was completed at trot in hand on a hard surface, and for both reins on the lunge on a soft surface. Six back kinematic and 3 movement symmetry parameters were calculated according to published methods. Movement symmetry values were side-corrected to allow comparison between reins on the lunge. A mixed model (P<0.05) evaluated the effects of the Equiband™ system over time, and trotting direction on back kinematic and movement symmetry parameters. RESULTS The Equiband™ system significantly reduced (all P<0.02) roll, pitch and mediolateral displacement in the cranial-mid thoracic region. Across all horses, back displacement and range of motion values were significantly greater (P<0.01) on the lunge than in a straight line, movement symmetry was consistent with having corrected all horses to be left-sided. CONCLUSION Preliminary results suggest the Equiband™ system may aid dynamic stabilisation of the vertebral column. Ethical animal research: This study was authorised by the Ethics and Welfare Committee of the Royal Veterinary College, London (URN Approval Number 1238). Written consent was obtained from the owner/keeper of each animal. SOURCE OF FUNDING Royal Veterinary College. Competing interests: N.C. Stubbs and N. Rombach developed the Equiband™ system. The remaining authors have no competing interests.
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Affiliation(s)
- V Simons
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, North Mymms, Hatfield, AL9 7TA, UK
| | - R Weller
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, North Mymms, Hatfield, AL9 7TA, UK
| | | | | | - T Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, North Mymms, Hatfield, AL9 7TA, UK
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Rhodin M, Egenvall A, Andersen P, Pfau T. Head and Pelvic Movement Asymmetries at Trot in Riding Horses Perceived as Sound by Their Owner. Equine Vet J 2015. [DOI: 10.1111/evj.12486_22] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. Rhodin
- Department of Clinical Sciences; Swedish University of Agricultural Sciences; SE-750 07 Uppsala Sweden
| | - A. Egenvall
- Department of Clinical Sciences; Swedish University of Agricultural Sciences; SE-750 07 Uppsala Sweden
| | - P.H. Andersen
- Department of Clinical Sciences; Swedish University of Agricultural Sciences; SE-750 07 Uppsala Sweden
| | - T. Pfau
- Department of Clinical Science and Services; The Royal Veterinary College; University of London; Hawkshead Lane, North Mymms Hatfield AL9 7TA UK
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Affiliation(s)
- L. Greve
- Centre for Equine Studies; Animal Health Trust; Lanwades Park, Kentford Newmarket Suffolk CB8 7UU UK
| | - S. Dyson
- Centre for Equine Studies; Animal Health Trust; Lanwades Park, Kentford Newmarket Suffolk CB8 7UU UK
| | - T. Pfau
- The Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
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Satchell G, McGrath M, Dixon J, Pfau T, Weller R. Effects of Time of Day, Ambient Temperature and Relative Humidity on the Repeatability of Infrared Thermographic Imaging in Horses. Equine Vet J 2015; 47 Suppl 48:13-4. [DOI: 10.1111/evj.12486_30] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- G. Satchell
- Department of Clinical Science and Services; The Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
| | - M. McGrath
- Department of Clinical Science and Services; The Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
| | - J. Dixon
- Department of Clinical Science and Services; The Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
| | - T. Pfau
- Department of Clinical Science and Services; The Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
| | - R. Weller
- Department of Clinical Science and Services; The Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
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35
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Ault B, Starling G, Parkes R, Pfau T, Pardoe C, Day P, Bettison C, Weller R. The Effect of Three Different Shoeing Conditions on Tendon Strain in the Thoroughbred Forelimb. Equine Vet J 2015. [DOI: 10.1111/evj.12486_39] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- B. Ault
- Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
| | - G. Starling
- Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
| | - R. Parkes
- Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
| | - T. Pfau
- Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
| | - C. Pardoe
- Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
| | - P. Day
- Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
| | - C. Bettison
- Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
| | - R. Weller
- Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
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Parkes R, Witte T, Pfau T, Weller R. An In VitroInvestigation of the Effect of Curve Running on Equine Distal Limb Tendon Strain. Equine Vet J 2015. [DOI: 10.1111/evj.12486_25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R.S.V. Parkes
- Structure and Motion Laboratory; Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
| | - T.H. Witte
- Structure and Motion Laboratory; Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
| | - T. Pfau
- Structure and Motion Laboratory; Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
| | - R. Weller
- Structure and Motion Laboratory; Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
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Pfau T, Parkes RS, Burden ER, Bell N, Fairhurst H, Witte TH. Movement asymmetry in working polo horses. Equine Vet J 2015; 48:517-22. [PMID: 26037947 DOI: 10.1111/evj.12467] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 05/26/2015] [Indexed: 11/29/2022]
Abstract
REASONS FOR PERFORMING STUDY The high, repetitive demands imposed on polo horses in training and competition may predispose them to musculoskeletal injuries and lameness. OBJECTIVES To quantify movement symmetry and lameness in a population of polo horses, and to investigate the existence of a relationship with age. STUDY DESIGN Convenience sampled cross-sectional study. METHODS Sixty polo horses were equipped with inertial measurement units (IMUs) attached to the poll, and between the tubera sacrale. Six movement symmetry measures were calculated for vertical head and pelvic displacement during in-hand trot and compared with values for perfect symmetry, compared between left and right limb lame horses, and compared with published thresholds for lameness. Regression lines were calculated as a function of age of horse. RESULTS Based on 2 different sets of published asymmetry thresholds 52-53% of the horses were quantified with head movement asymmetry and 27-50% with pelvic movement asymmetry resulting in 60-67% of horses being classified with movement asymmetry outside published guideline values for either the forelimbs, hindlimbs or both. Neither forelimb nor hindlimb asymmetries were preferentially left or right sided, with directional asymmetry values across all horses not different from perfect symmetry and absolute values not different between left and right lame horses (P values >0.6 for all forelimb symmetry measures and >0.2 for all hindlimb symmetry measures). None of the symmetry parameters increased or decreased significantly with age. CONCLUSIONS A large proportion of polo horses show gait asymmetries consistent with previously defined thresholds for lameness. These do not appear to be lateralised or associated with age.
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Affiliation(s)
- T Pfau
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hertfordshire, UK
| | - R S Parkes
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hertfordshire, UK
| | - E R Burden
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hertfordshire, UK
| | - N Bell
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hertfordshire, UK
| | - H Fairhurst
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hertfordshire, UK
| | - T H Witte
- Structure and Motion Lab and Clinical Science and Services, Royal Veterinary College, Hertfordshire, UK
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Pfau T, Fiske-Jackson A, Rhodin M. Quantitative assessment of gait parameters in horses: Useful for aiding clinical decision making? EQUINE VET EDUC 2015. [DOI: 10.1111/eve.12372] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- T. Pfau
- Department of Clinical Science and Services; The Royal Veterinary College; Hatfield UK
| | - A. Fiske-Jackson
- Department of Clinical Science and Services; The Royal Veterinary College; Hatfield UK
| | - M. Rhodin
- Department of Clinical Sciences; Swedish University of Agricultural Sciences; Uppsala Sweden
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Heim C, Pfau T, Gerber V, Schweizer C, Doherr M, Schüpbach-Regula G, Witte S. Determination of vertebral range of motion using inertial measurement units in 27 Franches-Montagnes stallions and comparison between conditions and with a mixed population. Equine Vet J 2015; 48:509-16. [DOI: 10.1111/evj.12455] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 04/19/2015] [Indexed: 11/28/2022]
Affiliation(s)
- C. Heim
- Swiss Institute of Equine Medicine; Vetsuisse Faculty; University of Berne and ALP-Haras; Berne Switzerland
| | - T. Pfau
- Department of Clinical Science and Services; The Royal Veterinary College; University of London; London UK
| | - V. Gerber
- Swiss Institute of Equine Medicine; Vetsuisse Faculty; University of Berne and ALP-Haras; Berne Switzerland
| | - C. Schweizer
- Swiss Institute of Equine Medicine; Vetsuisse Faculty; University of Berne and ALP-Haras; Berne Switzerland
| | - M. Doherr
- Veterinary Public Health Institute; Vetsuisse Faculty; University of Berne; Berne Switzerland
| | - G. Schüpbach-Regula
- Veterinary Public Health Institute; Vetsuisse Faculty; University of Berne; Berne Switzerland
| | - S. Witte
- Swiss Institute of Equine Medicine; Vetsuisse Faculty; University of Berne and ALP-Haras; Berne Switzerland
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Starke SD, May SA, Pfau T. Understanding hind limb lameness signs in horses using simple rigid body mechanics. J Biomech 2015; 48:3323-31. [PMID: 26163753 DOI: 10.1016/j.jbiomech.2015.06.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 02/17/2015] [Accepted: 06/15/2015] [Indexed: 11/18/2022]
Abstract
Hind limb lameness detection in horses relies on the identification of movement asymmetry which can be based on multiple pelvic landmarks. This study explains the poorly understood relationship between hind limb lameness pointers, related to the tubera coxae and sacrum, based on experimental data in context of a simple rigid body model. Vertical displacement of tubera coxae and sacrum was quantified experimentally in 107 horses with varying lameness degrees. A geometrical rigid-body model of pelvis movement during lameness was created in Matlab. Several asymmetry measures were calculated and contrasted. Results showed that model predictions for tubera coxae asymmetry during lameness matched experimental observations closely. Asymmetry for sacrum and comparative tubera coxae movement showed a strong association both empirically (R(2)≥ 0.92) and theoretically. We did not find empirical or theoretical evidence for a systematic, pronounced adaptation in the pelvic rotation pattern with increasing lameness. The model showed that the overall range of movement between tubera coxae does not allow the appreciation of asymmetry changes beyond mild lameness. When evaluating movement relative to the stride cycle we did find empirical evidence for asymmetry being slightly more visible when comparing tubera coxae amplitudes rather than sacrum amplitudes, although variation exists for mild lameness. In conclusion, the rigidity of the equine pelvis results in tightly linked movement trajectories of different pelvic landmarks. The model allows the explanation of empirical observations in the context of the underlying mechanics, helping the identification of potentially limited assessment choices when evaluating gait.
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Affiliation(s)
- S D Starke
- The Royal Veterinary College, Department of Clinical Science and Services, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, United Kingdom; Structure and Motion Lab, The Royal Veterinary College, United Kingdom.
| | - S A May
- The Royal Veterinary College, Department of Clinical Science and Services, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, United Kingdom
| | - T Pfau
- The Royal Veterinary College, Department of Clinical Science and Services, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, United Kingdom; Structure and Motion Lab, The Royal Veterinary College, United Kingdom
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41
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Pfau T, Boultbee H, Davis H, Walker A, Rhodin M. Agreement between two inertial sensor gait analysis systems for lameness examinations in horses. EQUINE VET EDUC 2015. [DOI: 10.1111/eve.12400] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- T. Pfau
- Department of Clinical Science and Services; The Royal Veterinary College; University of London; UK
| | - H. Boultbee
- Department of Clinical Science and Services; The Royal Veterinary College; University of London; UK
| | - H. Davis
- Department of Clinical Science and Services; The Royal Veterinary College; University of London; UK
| | - A. Walker
- Department of Clinical Science and Services; The Royal Veterinary College; University of London; UK
| | - M. Rhodin
- Department of Clinical Sciences; Swedish University of Agricultural Sciences; Uppsala Sweden
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Rhodin M, Roepstorff L, French A, Keegan KG, Pfau T, Egenvall A. Head and pelvic movement asymmetry during lungeing in horses with symmetrical movement on the straight. Equine Vet J 2015; 48:315-20. [PMID: 25808700 PMCID: PMC5032979 DOI: 10.1111/evj.12446] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 03/14/2015] [Indexed: 12/03/2022]
Abstract
Reasons for performing study Lungeing is commonly used as part of standard lameness examinations in horses. Knowledge of how lungeing influences motion symmetry in sound horses is needed. Objectives The aim of this study was to objectively evaluate the symmetry of vertical head and pelvic motion during lungeing in a large number of horses with symmetric motion during straight line evaluation. Study design Cross‐sectional prospective study. Methods A pool of 201 riding horses, all functioning well and considered sound by their owners, were evaluated in trot on a straight line and during lungeing to the left and right. From this pool, horses with symmetric vertical head and pelvic movement during the straight line trot (n = 94) were retained for analysis. Vertical head and pelvic movements were measured with body mounted uniaxial accelerometers. Differences between vertical maximum and minimum head (HDmax, HDmin) and pelvic (PDmax, PDmin) heights between left and right forelimb and hindlimb stances were compared between straight line trot and lungeing in either direction. Results Vertical head and pelvic movements during lungeing were more asymmetric than during trot on a straight line. Common asymmetric patterns seen in the head were more upward movement during push‐off of the outside forelimb and less downward movement during impact of the inside limb. Common asymmetric patterns seen in the pelvis were less upward movement during push‐off of the outside hindlimb and less downward movement of the pelvis during impact of the inside hindlimb. Asymmetric patterns in one lunge direction were frequently not the same as in the opposite direction. Conclusions Lungeing induces systematic asymmetries in vertical head and pelvic motion patterns in horses that may not be the same in both directions. These asymmetries may mask or mimic fore‐ or hindlimb lameness.
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Affiliation(s)
- M Rhodin
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - L Roepstorff
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - A French
- College of Veterinary Medicine, University of Missouri, Columbia, USA
| | - K G Keegan
- College of Veterinary Medicine, University of Missouri, Columbia, USA
| | - T Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, North Mymms, Hatfield, UK
| | - A Egenvall
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Urvoy A, Ripka F, Lesanovsky I, Booth D, Shaffer JP, Pfau T, Löw R. Strongly Correlated Growth of Rydberg Aggregates in a Vapor Cell. Phys Rev Lett 2015; 114:203002. [PMID: 26047226 DOI: 10.1103/physrevlett.114.203002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Indexed: 06/04/2023]
Abstract
The observation of strongly interacting many-body phenomena in atomic gases typically requires ultracold samples. Here we show that the strong interaction potentials between Rydberg atoms enable the observation of many-body effects in an atomic vapor, even at room temperature. We excite Rydberg atoms in cesium vapor and observe in real time an out-of-equilibrium excitation dynamics that is consistent with an aggregation mechanism. The experimental observations show qualitative and quantitative agreement with a microscopic theoretical model. Numerical simulations reveal that the strongly correlated growth of the emerging aggregates is reminiscent of soft-matter type systems.
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Affiliation(s)
- A Urvoy
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - F Ripka
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - I Lesanovsky
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - D Booth
- Homer L. Dodge Department of Physics and Astronomy, The University of Oklahoma, 440 West Brooks Street, Norman, Oklahoma 73019, USA
| | - J P Shaffer
- Homer L. Dodge Department of Physics and Astronomy, The University of Oklahoma, 440 West Brooks Street, Norman, Oklahoma 73019, USA
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - R Löw
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
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Hammarberg M, Egenvall A, Pfau T, Rhodin M. Rater agreement of visual lameness assessment in horses during lungeing. Equine Vet J 2015; 48:78-82. [PMID: 25399722 PMCID: PMC4964936 DOI: 10.1111/evj.12385] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 11/09/2014] [Indexed: 11/30/2022]
Abstract
REASONS FOR PERFORMING STUDY Lungeing is an important part of lameness examinations as the circular path may accentuate low-grade lameness. Movement asymmetries related to the circular path, to compensatory movements and to pain make the lameness evaluation complex. Scientific studies have shown high inter-rater variation when assessing lameness during straight line movement. OBJECTIVES The aim was to estimate inter- and intra-rater agreement of equine veterinarians evaluating lameness from videos of sound and lame horses during lungeing and to investigate the influence of veterinarians' experience and the objective degree of movement asymmetry on rater agreement. STUDY DESIGN Cross-sectional observational study. METHODS Video recordings and quantitative gait analysis with inertial sensors were performed in 23 riding horses of various breeds. The horses were examined at trot on a straight line and during lungeing on soft or hard surfaces in both directions. One video sequence was recorded per condition and the horses were classified as forelimb lame, hindlimb lame or sound from objective straight line symmetry measurements. Equine veterinarians (n = 86), including 43 with >5 years of orthopaedic experience, participated in a web-based survey and were asked to identify the lamest limb on 60 videos, including 10 repeats. The agreements between (inter-rater) and within (intra-rater) veterinarians were analysed with κ statistics (Fleiss, Cohen). RESULTS Inter-rater agreement κ was 0.31 (0.38/0.25 for experienced/less experienced) and higher for forelimb (0.33) than for hindlimb lameness (0.11) or soundness (0.08) evaluation. Median intra-rater agreement κ was 0.57. CONCLUSIONS Inter-rater agreement was poor for less experienced raters, and for all raters when evaluating hindlimb lameness. Since identification of the lame limb/limbs is a prerequisite for successful diagnosis, treatment and recovery, the high inter-rater variation when evaluating lameness on the lunge is likely to influence the accuracy and repeatability of lameness examinations and, indirectly, the efficacy of treatment.
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Affiliation(s)
- M Hammarberg
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - A Egenvall
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - T Pfau
- Department of Veterinary Clinical Sciences, The Royal Veterinary College, University of London, Hatfield, UK
| | - M Rhodin
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Wilson A, Agass R, Vaux S, Sherlock E, Day P, Pfau T, Weller R. Foot placement of the equine forelimb: Relationship between foot conformation, foot placement and movement asymmetry. Equine Vet J 2014; 48:90-6. [PMID: 25523459 DOI: 10.1111/evj.12378] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 09/30/2014] [Indexed: 11/30/2022]
Abstract
REASONS FOR PERFORMING STUDY Hoof conformation, foot placement and movement asymmetry are routinely assessed as part of the lameness examination. However, to date, few studies have described these parameters, or the interplay between them, in the general horse population. OBJECTIVES To assess foot conformation and foot placement in the forelimbs of a group of general purpose horses and investigate the relationships between foot placement, foot conformation and movement asymmetry. STUDY DESIGN Observational cross-sectional study. METHODS Forty-three horses were included in the study. Measurements were taken from photographs of each forelimb to assess foot conformation. Video footage was recorded simultaneously from perpendicular cameras at both walk and trot and used to categorise foot placement. Inertial sensor data were used to assess head movement asymmetry in trot. RESULTS There was a high degree of variation in foot placement between and within horses, but a 'lateral heel' placement was most common in walk and a 'lateral' placement most common in trot. Foot placement was associated with dorsal and palmar hoof angles but there was no relationship between foot placement and the other conformation parameters, nor with movement asymmetry. Moderate negative correlations were found between several of the conformation parameters and movement asymmetry. CONCLUSIONS A relationship exists between foot conformation and movement asymmetry with decreasing hoof width and hoof length related to increasing amount of movement asymmetry. In the population of horses studied here--deemed to be 'well functioning' by their owners/riders--foot placement was found to be independent of movement asymmetry and, to a large extent, independent of foot conformation.
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Affiliation(s)
- A Wilson
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - R Agass
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - S Vaux
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - E Sherlock
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - P Day
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - T Pfau
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - R Weller
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, UK
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Pfau T, Jennings C, Mitchell H, Olsen E, Walker A, Egenvall A, Tröster S, Weller R, Rhodin M. Lungeing on hard and soft surfaces: Movement symmetry of trotting horses considered sound by their owners. Equine Vet J 2014; 48:83-9. [PMID: 25297461 DOI: 10.1111/evj.12374] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 09/30/2014] [Indexed: 11/30/2022]
Abstract
REASONS FOR PERFORMING STUDY Lungeing is often part of the clinical lameness examination. The difference in movement symmetry, which is a commonly employed lameness measure, has not been quantified between surfaces. OBJECTIVES To compare head and pelvic movement symmetry between surfaces and reins during lungeing. STUDY DESIGN Quantitative gait analysis in 23 horses considered sound by their owners. METHODS Twenty-three horses were assessed in-hand and on the lunge on both reins on hard and soft surfaces with inertial sensors. Seven movement symmetry parameters were quantified and used to establish 2 groups, namely symmetrical (n = 9) and forelimb-lame horses (n = 14), based on values from straight-line assessment. Movement symmetry values for left rein measurements were side corrected to allow comparison of the amount of movement symmetry between reins. A mixed model (P<0.05) was used to study effects on movement symmetry of surface (hard/soft) and rein (inside/outside with respect to movement symmetry on the straight). RESULTS In forelimb-lame horses, surface and rein were identified as significantly affecting all head movement symmetry measures (rein, all P<0.0001; surface, all P<0.042). In the symmetrical group, no significant influence of surface or rein was identified for head movement symmetry (rein, all P>0.245; surface, all P>0.073). No significant influence of surface or rein was identified for any of the pelvic movement symmetry measures in either group. CONCLUSIONS While more symmetrical horses showed a consistent amount of movement symmetry across surfaces/reins, horses objectively quantified as lame on the straight showed decreased movement symmetry during lungeing, in particular with the lame limb on the inside of a hard circle. The variation within group questions straight-line movement symmetry as a sole measure of lameness without quantification of movement symmetry on the lunge, ideally on hard and soft surfaces to evaluate differences between reins and surfaces. In future, thresholds for lungeing need to be determined using simultaneous visual and objective assessment.
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Affiliation(s)
- T Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hatfield, UK
| | - C Jennings
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hatfield, UK
| | - H Mitchell
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hatfield, UK
| | - E Olsen
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hatfield, UK.,Department of Large Animal Sciences, Faculty of Health and Medical Science, University of Copenhagen, Taastrup, Denmark
| | - A Walker
- Equine Studies, Moulton College, Moulton, UK
| | - A Egenvall
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - S Tröster
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hatfield, UK
| | - R Weller
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hatfield, UK
| | - M Rhodin
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Roach J, Pfau T, Bryars J, Unt V, Channon S, Weller R. Sagittal distal limb kinematics inside the hoof capsule captured using high-speed fluoroscopy in walking and trotting horses. Vet J 2014; 202:94-8. [DOI: 10.1016/j.tvjl.2014.06.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 06/10/2014] [Accepted: 06/11/2014] [Indexed: 11/16/2022]
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Starke S, Pfau T, May S. How do Students Approach Lameness? A Case Study. Equine Vet J 2014. [DOI: 10.1111/evj.12323_41] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S.D. Starke
- The Royal Veterinary College; Department of Clinical Science and Services; Hatfield Hertfordshire AL9 7TA UK
| | - T. Pfau
- The Royal Veterinary College; Department of Clinical Science and Services; Hatfield Hertfordshire AL9 7TA UK
| | - S.A. May
- The Royal Veterinary College; Department of Clinical Science and Services; Hatfield Hertfordshire AL9 7TA UK
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Starke S, May S, Pfau T. Fifty Ways to Do Your Lameness: The Relationship Between Various Pelvis-Based Visual Lameness Pointers During Hindlimb Lameness. Equine Vet J 2014. [DOI: 10.1111/evj.12323_40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- S.D. Starke
- The Royal Veterinary College; Department of Clinical Science and Services; Hatfield Hertfordshire AL9 7TA UK
| | - S.A. May
- The Royal Veterinary College; Department of Clinical Science and Services; Hatfield Hertfordshire AL9 7TA UK
| | - T. Pfau
- The Royal Veterinary College; Department of Clinical Science and Services; Hatfield Hertfordshire AL9 7TA UK
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Sharp H, Pfau T, Hopkins S. The Effect of Hindlimb Studs on Movement Symmetry in Horses During Lungeing. Equine Vet J 2014. [DOI: 10.1111/evj.12323_45] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- H. Sharp
- The Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire UK
| | - T. Pfau
- The Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire UK
| | - S. Hopkins
- The Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire UK
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