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Sample records for intact flagellar motor

  1. Exchange of rotor components in functioning bacterial flagellar motor

    International Nuclear Information System (INIS)

    Fukuoka, Hajime; Inoue, Yuichi; Terasawa, Shun; Takahashi, Hiroto; Ishijima, Akihiko

    2010-01-01

    The bacterial flagellar motor is a rotary motor driven by the electrochemical potential of a coupling ion. The interaction between a rotor and stator units is thought to generate torque. The overall structure of flagellar motor has been thought to be static, however, it was recently proved that stators are exchanged in a rotating motor. Understanding the dynamics of rotor components in functioning motor is important for the clarifying of working mechanism of bacterial flagellar motor. In this study, we focused on the dynamics and the turnover of rotor components in a functioning flagellar motor. Expression systems for GFP-FliN, FliM-GFP, and GFP-FliG were constructed, and each GFP-fusion was functionally incorporated into the flagellar motor. To investigate whether the rotor components are exchanged in a rotating motor, we performed fluorescence recovery after photobleaching experiments using total internal reflection fluorescence microscopy. After photobleaching, in a tethered cell producing GFP-FliN or FliM-GFP, the recovery of fluorescence at the rotational center was observed. However, in a cell producing GFP-FliG, no recovery of fluorescence was observed. The transition phase of fluorescence intensity after full or partially photobleaching allowed the turnover of FliN subunits to be calculated as 0.0007 s -1 , meaning that FliN would be exchanged in tens of minutes. These novel findings indicate that a bacterial flagellar motor is not a static structure even in functioning state. This is the first report for the exchange of rotor components in a functioning bacterial flagellar motor.

  2. Applying torque to the Escherichia coli flagellar motor using magnetic tweezers

    NARCIS (Netherlands)

    van Oene, M.M.; Dickinson, L.E.; Cross, B.; Pedaci, F.; Lipfert, J.; Dekker, N.H.

    2017-01-01

    The bacterial flagellar motor of Escherichia coli is a nanoscale rotary engine essential for bacterial propulsion. Studies on the power output of single motors rely on the measurement of motor torque and rotation under external load. Here, we investigate the use of magnetic tweezers, which in

  3. An Element of Determinism in a Stochastic Flagellar Motor Switch.

    Science.gov (United States)

    Xie, Li; Altindal, Tuba; Wu, Xiao-Lun

    2015-01-01

    Marine bacterium Vibrio alginolyticus uses a single polar flagellum to navigate in an aqueous environment. Similar to Escherichia coli cells, the polar flagellar motor has two states; when the motor is counter-clockwise, the cell swims forward and when the motor is clockwise, the cell swims backward. V. alginolyticus also incorporates a direction randomization step at the start of the forward swimming interval by flicking its flagellum. To gain an understanding on how the polar flagellar motor switch is regulated, distributions of the forward Δf and backward Δb intervals are investigated herein. We found that the steady-state probability density functions, P(Δf) and P(Δb), of freely swimming bacteria are strongly peaked at a finite time, suggesting that the motor switch is not Poissonian. The short-time inhibition is sufficiently strong and long lasting, i.e., several hundred milliseconds for both intervals, which is readily observed and characterized. Treating motor reversal dynamics as a first-passage problem, which results from conformation fluctuations of the motor switch, we calculated P(Δf) and P(Δb) and found good agreement with the measurements.

  4. Applying torque to the Escherichia coli flagellar motor using magnetic tweezers

    Science.gov (United States)

    van Oene, Maarten M.; Dickinson, Laura E.; Cross, Bronwen; Pedaci, Francesco; Lipfert, Jan; Dekker, Nynke H.

    2017-01-01

    The bacterial flagellar motor of Escherichia coli is a nanoscale rotary engine essential for bacterial propulsion. Studies on the power output of single motors rely on the measurement of motor torque and rotation under external load. Here, we investigate the use of magnetic tweezers, which in principle allow the application and active control of a calibrated load torque, to study single flagellar motors in Escherichia coli. We manipulate the external load on the motor by adjusting the magnetic field experienced by a magnetic bead linked to the motor, and we probe the motor’s response. A simple model describes the average motor speed over the entire range of applied fields. We extract the motor torque at stall and find it to be similar to the motor torque at drag-limited speed. In addition, use of the magnetic tweezers allows us to force motor rotation in both forward and backward directions. We monitor the motor’s performance before and after periods of forced rotation and observe no destructive effects on the motor. Our experiments show how magnetic tweezers can provide active and fast control of the external load while also exposing remaining challenges in calibration. Through their non-invasive character and straightforward parallelization, magnetic tweezers provide an attractive platform to study nanoscale rotary motors at the single-motor level. PMID:28266562

  5. Mechanics of torque generation in the bacterial flagellar motor.

    Science.gov (United States)

    Mandadapu, Kranthi K; Nirody, Jasmine A; Berry, Richard M; Oster, George

    2015-08-11

    The bacterial flagellar motor (BFM) is responsible for driving bacterial locomotion and chemotaxis, fundamental processes in pathogenesis and biofilm formation. In the BFM, torque is generated at the interface between transmembrane proteins (stators) and a rotor. It is well established that the passage of ions down a transmembrane gradient through the stator complex provides the energy for torque generation. However, the physics involved in this energy conversion remain poorly understood. Here we propose a mechanically specific model for torque generation in the BFM. In particular, we identify roles for two fundamental forces involved in torque generation: electrostatic and steric. We propose that electrostatic forces serve to position the stator, whereas steric forces comprise the actual "power stroke." Specifically, we propose that ion-induced conformational changes about a proline "hinge" residue in a stator α-helix are directly responsible for generating the power stroke. Our model predictions fit well with recent experiments on a single-stator motor. The proposed model provides a mechanical explanation for several fundamental properties of the flagellar motor, including torque-speed and speed-ion motive force relationships, backstepping, variation in step sizes, and the effects of key mutations in the stator.

  6. Bio-hybrid micro/nanodevices powered by flagellar motor: challenges and strategies

    Directory of Open Access Journals (Sweden)

    Jin-Woo eKim

    2015-07-01

    Full Text Available Molecular motors, which are precision-engineered by nature, offer exciting possibilities for bio-hybrid engineered systems. They could enable real applications ranging from micro/nano fluidics, to biosensing, to medical diagnoses. This review describes the fundamental biological insights and fascinating potentials of these remarkable sensing and actuation machines, in particular bacterial flagellar motors, as well as their engineering perspectives with regard to applications in bio-engineered hybrid systems and nanobiotechnology.

  7. Model Studies of the Dynamics of Bacterial Flagellar Motors

    Science.gov (United States)

    Bai, Fan; Lo, Chien-Jung; Berry, Richard M.; Xing, Jianhua

    2009-01-01

    Abstract The bacterial flagellar motor is a rotary molecular machine that rotates the helical filaments that propel swimming bacteria. Extensive experimental and theoretical studies exist on the structure, assembly, energy input, power generation, and switching mechanism of the motor. In a previous article, we explained the general physics underneath the observed torque-speed curves with a simple two-state Fokker-Planck model. Here, we further analyze that model, showing that 1), the model predicts that the two components of the ion motive force can affect the motor dynamics differently, in agreement with latest experiments; 2), with explicit consideration of the stator spring, the model also explains the lack of dependence of the zero-load speed on stator number in the proton motor, as recently observed; and 3), the model reproduces the stepping behavior of the motor even with the existence of the stator springs and predicts the dwell-time distribution. The predicted stepping behavior of motors with two stators is discussed, and we suggest future experimental procedures for verification. PMID:19383460

  8. Model Studies of the Dynamics of Bacterial Flagellar Motors

    Energy Technology Data Exchange (ETDEWEB)

    Bai, F; Lo, C; Berry, R; Xing, J

    2009-03-19

    The Bacterial Flagellar Motor is a rotary molecular machine that rotates the helical filaments which propel swimming bacteria. Extensive experimental and theoretical studies exist on the structure, assembly, energy input, power generation and switching mechanism of the motor. In our previous paper, we explained the general physics underneath the observed torque-speed curves with a simple two-state Fokker-Planck model. Here we further analyze this model. In this paper we show (1) the model predicts that the two components of the ion motive force can affect the motor dynamics differently, in agreement with the latest experiment by Lo et al.; (2) with explicit consideration of the stator spring, the model also explains the lack of dependence of the zero-load speed on stator number in the proton motor, recently observed by Yuan and Berg; (3) the model reproduces the stepping behavior of the motor even with the existence of the stator springs and predicts the dwelling time distribution. Predicted stepping behavior of motors with two stators is discussed, and we suggest future experimental verification.

  9. Impact of fluorescent protein fusions on the bacterial flagellar motor.

    Science.gov (United States)

    Heo, M; Nord, A L; Chamousset, D; van Rijn, E; Beaumont, H J E; Pedaci, F

    2017-10-03

    Fluorescent fusion proteins open a direct and unique window onto protein function. However, they also introduce the risk of perturbation of the function of the native protein. Successful applications of fluorescent fusions therefore rely on a careful assessment and minimization of the side effects, but such insight is still lacking for many applications. This is particularly relevant in the study of the internal dynamics of motor proteins, where both the chemical and mechanical reaction coordinates can be affected. Fluorescent proteins fused to the stator of the Bacterial Flagellar Motor (BFM) have previously been used to unveil the motor subunit dynamics. Here we report the effects on single motors of three fluorescent proteins fused to the stators, all of which altered BFM behavior. The torque generated by individual stators was reduced while their stoichiometry remained unaffected. MotB fusions decreased the switching frequency and induced a novel bias-dependent asymmetry in the speed in the two directions. These effects could be mitigated by inserting a linker at the fusion point. These findings provide a quantitative account of the effects of fluorescent fusions to the stator on BFM dynamics and their alleviation- new insights that advance the use of fluorescent fusions to probe the dynamics of protein complexes.

  10. Second-chance signal transduction explains cooperative flagellar switching.

    Science.gov (United States)

    Zot, Henry G; Hasbun, Javier E; Minh, Nguyen Van

    2012-01-01

    The reversal of flagellar motion (switching) results from the interaction between a switch complex of the flagellar rotor and a torque-generating stationary unit, or stator (motor unit). To explain the steeply cooperative ligand-induced switching, present models propose allosteric interactions between subunits of the rotor, but do not address the possibility of a reaction that stimulates a bidirectional motor unit to reverse direction of torque. During flagellar motion, the binding of a ligand-bound switch complex at the dwell site could excite a motor unit. The probability that another switch complex of the rotor, moving according to steady-state rotation, will reach the same dwell site before that motor unit returns to ground state will be determined by the independent decay rate of the excited-state motor unit. Here, we derive an analytical expression for the energy coupling between a switch complex and a motor unit of the stator complex of a flagellum, and demonstrate that this model accounts for the cooperative switching response without the need for allosteric interactions. The analytical result can be reproduced by simulation when (1) the motion of the rotor delivers a subsequent ligand-bound switch to the excited motor unit, thereby providing the excited motor unit with a second chance to remain excited, and (2) the outputs from multiple independent motor units are constrained to a single all-or-none event. In this proposed model, a motor unit and switch complex represent the components of a mathematically defined signal transduction mechanism in which energy coupling is driven by steady-state and is regulated by stochastic ligand binding. Mathematical derivation of the model shows the analytical function to be a general form of the Hill equation (Hill AV (1910) The possible effects of the aggregation of the molecules of haemoglobin on its dissociation curves. J Physiol 40: iv-vii).

  11. H(+) and Na(+) are involved in flagellar rotation of the spirochete Leptospira.

    Science.gov (United States)

    Islam, Md Shafiqul; Morimoto, Yusuke V; Kudo, Seishi; Nakamura, Shuichi

    2015-10-16

    Leptospira is a spirochete possessing intracellular flagella. Each Leptospira flagellar filament is linked with a flagellar motor composed of a rotor and a dozen stators. For many bacterial species, it is known that the stator functions as an ion channel and that the ion flux through the stator is coupled with flagellar rotation. The coupling ion varies depending on the species; for example, H(+) is used in Escherichia coli, and Na(+) is used in Vibrio spp. to drive a polar flagellum. Although genetic and structural studies illustrated that the Leptospira flagellar motor also contains a stator, the coupling ion for flagellar rotation remains unknown. In the present study, we analyzed the motility of Leptospira under various pH values and salt concentrations. Leptospira cells displayed motility in acidic to alkaline pH. In the presence of a protonophore, the cells completely lost motility in acidic to neutral pH but displayed extremely slow movement under alkaline conditions. This result suggests that H(+) is a major coupling ion for flagellar rotation over a wide pH range; however, we also observed that the motility of Leptospira was significantly enhanced by the addition of Na(+), though it vigorously moved even under Na(+)-free conditions. These results suggest that H(+) is preferentially used and that Na(+) is secondarily involved in flagellar rotation in Leptospira. The flexible ion selectivity in the flagellar system could be advantageous for Leptospira to survive in a wide range of environment. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. H+ and Na+ are involved in flagellar rotation of the spirochete Leptospira

    International Nuclear Information System (INIS)

    Islam, Md. Shafiqul; Morimoto, Yusuke V.; Kudo, Seishi; Nakamura, Shuichi

    2015-01-01

    Leptospira is a spirochete possessing intracellular flagella. Each Leptospira flagellar filament is linked with a flagellar motor composed of a rotor and a dozen stators. For many bacterial species, it is known that the stator functions as an ion channel and that the ion flux through the stator is coupled with flagellar rotation. The coupling ion varies depending on the species; for example, H + is used in Escherichia coli, and Na + is used in Vibrio spp. to drive a polar flagellum. Although genetic and structural studies illustrated that the Leptospira flagellar motor also contains a stator, the coupling ion for flagellar rotation remains unknown. In the present study, we analyzed the motility of Leptospira under various pH values and salt concentrations. Leptospira cells displayed motility in acidic to alkaline pH. In the presence of a protonophore, the cells completely lost motility in acidic to neutral pH but displayed extremely slow movement under alkaline conditions. This result suggests that H + is a major coupling ion for flagellar rotation over a wide pH range; however, we also observed that the motility of Leptospira was significantly enhanced by the addition of Na + , though it vigorously moved even under Na + -free conditions. These results suggest that H + is preferentially used and that Na + is secondarily involved in flagellar rotation in Leptospira. The flexible ion selectivity in the flagellar system could be advantageous for Leptospira to survive in a wide range of environment. - Highlights: • This is a study on input energy for motility in the spirochete Leptospira. • Leptospira biflexa exhibited active motility in acidic to alkaline pH. • Both H + and Na + are involved in flagellar rotation in Leptospira. • H + is a primary energy source, but Na + can secondarily enhance motility.

  13. Proteomic Analysis of Intact Flagella of Procyclic Trypanosoma brucei Cells Identifies Novel Flagellar Proteins with Unique Sub-localization and Dynamics*

    Science.gov (United States)

    Subota, Ines; Julkowska, Daria; Vincensini, Laetitia; Reeg, Nele; Buisson, Johanna; Blisnick, Thierry; Huet, Diego; Perrot, Sylvie; Santi-Rocca, Julien; Duchateau, Magalie; Hourdel, Véronique; Rousselle, Jean-Claude; Cayet, Nadège; Namane, Abdelkader; Chamot-Rooke, Julia; Bastin, Philippe

    2014-01-01

    Cilia and flagella are complex organelles made of hundreds of proteins of highly variable structures and functions. Here we report the purification of intact flagella from the procyclic stage of Trypanosoma brucei using mechanical shearing. Structural preservation was confirmed by transmission electron microscopy that showed that flagella still contained typical elements such as the membrane, the axoneme, the paraflagellar rod, and the intraflagellar transport particles. It also revealed that flagella severed below the basal body, and were not contaminated by other cytoskeletal structures such as the flagellar pocket collar or the adhesion zone filament. Mass spectrometry analysis identified a total of 751 proteins with high confidence, including 88% of known flagellar components. Comparison with the cell debris fraction revealed that more than half of the flagellum markers were enriched in flagella and this enrichment criterion was taken into account to identify 212 proteins not previously reported to be associated to flagella. Nine of these were experimentally validated including a 14-3-3 protein not yet reported to be associated to flagella and eight novel proteins termed FLAM (FLAgellar Member). Remarkably, they localized to five different subdomains of the flagellum. For example, FLAM6 is restricted to the proximal half of the axoneme, no matter its length. In contrast, FLAM8 is progressively accumulating at the distal tip of growing flagella and half of it still needs to be added after cell division. A combination of RNA interference and Fluorescence Recovery After Photobleaching approaches demonstrated very different dynamics from one protein to the other, but also according to the stage of construction and the age of the flagellum. Structural proteins are added to the distal tip of the elongating flagellum and exhibit slow turnover whereas membrane proteins such as the arginine kinase show rapid turnover without a detectible polarity. PMID:24741115

  14. Proteomic analysis of intact flagella of procyclic Trypanosoma brucei cells identifies novel flagellar proteins with unique sub-localization and dynamics.

    Science.gov (United States)

    Subota, Ines; Julkowska, Daria; Vincensini, Laetitia; Reeg, Nele; Buisson, Johanna; Blisnick, Thierry; Huet, Diego; Perrot, Sylvie; Santi-Rocca, Julien; Duchateau, Magalie; Hourdel, Véronique; Rousselle, Jean-Claude; Cayet, Nadège; Namane, Abdelkader; Chamot-Rooke, Julia; Bastin, Philippe

    2014-07-01

    Cilia and flagella are complex organelles made of hundreds of proteins of highly variable structures and functions. Here we report the purification of intact flagella from the procyclic stage of Trypanosoma brucei using mechanical shearing. Structural preservation was confirmed by transmission electron microscopy that showed that flagella still contained typical elements such as the membrane, the axoneme, the paraflagellar rod, and the intraflagellar transport particles. It also revealed that flagella severed below the basal body, and were not contaminated by other cytoskeletal structures such as the flagellar pocket collar or the adhesion zone filament. Mass spectrometry analysis identified a total of 751 proteins with high confidence, including 88% of known flagellar components. Comparison with the cell debris fraction revealed that more than half of the flagellum markers were enriched in flagella and this enrichment criterion was taken into account to identify 212 proteins not previously reported to be associated to flagella. Nine of these were experimentally validated including a 14-3-3 protein not yet reported to be associated to flagella and eight novel proteins termed FLAM (FLAgellar Member). Remarkably, they localized to five different subdomains of the flagellum. For example, FLAM6 is restricted to the proximal half of the axoneme, no matter its length. In contrast, FLAM8 is progressively accumulating at the distal tip of growing flagella and half of it still needs to be added after cell division. A combination of RNA interference and Fluorescence Recovery After Photobleaching approaches demonstrated very different dynamics from one protein to the other, but also according to the stage of construction and the age of the flagellum. Structural proteins are added to the distal tip of the elongating flagellum and exhibit slow turnover whereas membrane proteins such as the arginine kinase show rapid turnover without a detectible polarity. © 2014 by The

  15. Temperature Dependences of Torque Generation and Membrane Voltage in the Bacterial Flagellar Motor

    Science.gov (United States)

    Inoue, Yuichi; Baker, Matthew A.B.; Fukuoka, Hajime; Takahashi, Hiroto; Berry, Richard M.; Ishijima, Akihiko

    2013-01-01

    In their natural habitats bacteria are frequently exposed to sudden changes in temperature that have been shown to affect their swimming. With our believed to be new methods of rapid temperature control for single-molecule microscopy, we measured here the thermal response of the Na+-driven chimeric motor expressed in Escherichia coli cells. Motor torque at low load (0.35 μm bead) increased linearly with temperature, twofold between 15°C and 40°C, and torque at high load (1.0 μm bead) was independent of temperature, as reported for the H+-driven motor. Single cell membrane voltages were measured by fluorescence imaging and these were almost constant (∼120 mV) over the same temperature range. When the motor was heated above 40°C for 1–2 min the torque at high load dropped reversibly, recovering upon cooling below 40°C. This response was repeatable over as many as 10 heating cycles. Both increases and decreases in torque showed stepwise torque changes with unitary size ∼150 pN nm, close to the torque of a single stator at room temperature (∼180 pN nm), indicating that dynamic stator dissociation occurs at high temperature, with rebinding upon cooling. Our results suggest that the temperature-dependent assembly of stators is a general feature of flagellar motors. PMID:24359752

  16. Speed of the bacterial flagellar motor near zero load depends on the number of stator units.

    Science.gov (United States)

    Nord, Ashley L; Sowa, Yoshiyuki; Steel, Bradley C; Lo, Chien-Jung; Berry, Richard M

    2017-10-31

    The bacterial flagellar motor (BFM) rotates hundreds of times per second to propel bacteria driven by an electrochemical ion gradient. The motor consists of a rotor 50 nm in diameter surrounded by up to 11 ion-conducting stator units, which exchange between motors and a membrane-bound pool. Measurements of the torque-speed relationship guide the development of models of the motor mechanism. In contrast to previous reports that speed near zero torque is independent of the number of stator units, we observe multiple speeds that we attribute to different numbers of units near zero torque in both Na + - and H + -driven motors. We measure the full torque-speed relationship of one and two H + units in Escherichia coli by selecting the number of H + units and controlling the number of Na + units in hybrid motors. These experiments confirm that speed near zero torque in H + -driven motors increases with the stator number. We also measured 75 torque-speed curves for Na + -driven chimeric motors at different ion-motive force and stator number. Torque and speed were proportional to ion-motive force and number of stator units at all loads, allowing all 77 measured torque-speed curves to be collapsed onto a single curve by simple rescaling. Published under the PNAS license.

  17. H{sup +} and Na{sup +} are involved in flagellar rotation of the spirochete Leptospira

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Md. Shafiqul [Department of Applied Physics, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Morimoto, Yusuke V. [Quantitative Biology Center, RIKEN, 6-2-3 Furuedai, Suita, Osaka 565-0874 (Japan); Graduate School of Frontier BioSciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kudo, Seishi [Department of Applied Physics, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Nakamura, Shuichi, E-mail: naka@bp.apph.tohoku.ac.jp [Department of Applied Physics, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Graduate School of Frontier BioSciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2015-10-16

    Leptospira is a spirochete possessing intracellular flagella. Each Leptospira flagellar filament is linked with a flagellar motor composed of a rotor and a dozen stators. For many bacterial species, it is known that the stator functions as an ion channel and that the ion flux through the stator is coupled with flagellar rotation. The coupling ion varies depending on the species; for example, H{sup +} is used in Escherichia coli, and Na{sup +} is used in Vibrio spp. to drive a polar flagellum. Although genetic and structural studies illustrated that the Leptospira flagellar motor also contains a stator, the coupling ion for flagellar rotation remains unknown. In the present study, we analyzed the motility of Leptospira under various pH values and salt concentrations. Leptospira cells displayed motility in acidic to alkaline pH. In the presence of a protonophore, the cells completely lost motility in acidic to neutral pH but displayed extremely slow movement under alkaline conditions. This result suggests that H{sup +} is a major coupling ion for flagellar rotation over a wide pH range; however, we also observed that the motility of Leptospira was significantly enhanced by the addition of Na{sup +}, though it vigorously moved even under Na{sup +}-free conditions. These results suggest that H{sup +} is preferentially used and that Na{sup +} is secondarily involved in flagellar rotation in Leptospira. The flexible ion selectivity in the flagellar system could be advantageous for Leptospira to survive in a wide range of environment. - Highlights: • This is a study on input energy for motility in the spirochete Leptospira. • Leptospira biflexa exhibited active motility in acidic to alkaline pH. • Both H{sup +} and Na{sup +} are involved in flagellar rotation in Leptospira. • H{sup +} is a primary energy source, but Na{sup +} can secondarily enhance motility.

  18. Flagellar Synchronization Is a Simple Alternative to Cell Cycle Synchronization for Ciliary and Flagellar Studies.

    Science.gov (United States)

    Dutta, Soumita; Avasthi, Prachee

    2017-01-01

    The unicellular green alga Chlamydomonas reinhardtii is an ideal model organism for studies of ciliary function and assembly. In assays for biological and biochemical effects of various factors on flagellar structure and function, synchronous culture is advantageous for minimizing variability. Here, we have characterized a method in which 100% synchronization is achieved with respect to flagellar length but not with respect to the cell cycle. The method requires inducing flagellar regeneration by amputation of the entire cell population and limiting regeneration time. This results in a maximally homogeneous distribution of flagellar lengths at 3 h postamputation. We found that time-limiting new protein synthesis during flagellar synchronization limits variability in the unassembled pool of limiting flagellar protein and variability in flagellar length without affecting the range of cell volumes. We also found that long- and short-flagella mutants that regenerate normally require longer and shorter synchronization times, respectively. By minimizing flagellar length variability using a simple method requiring only hours and no changes in media, flagellar synchronization facilitates the detection of small changes in flagellar length resulting from both chemical and genetic perturbations in Chlamydomonas . This method increases our ability to probe the basic biology of ciliary size regulation and related disease etiologies. IMPORTANCE Cilia and flagella are highly conserved antenna-like organelles that found in nearly all mammalian cell types. They perform sensory and motile functions contributing to numerous physiological and developmental processes. Defects in their assembly and function are implicated in a wide range of human diseases ranging from retinal degeneration to cancer. Chlamydomonas reinhardtii is an algal model system for studying mammalian cilium formation and function. Here, we report a simple synchronization method that allows detection of small

  19. Kinematics of flagellar swimming in Euglena gracilis: Helical trajectories and flagellar shapes.

    Science.gov (United States)

    Rossi, Massimiliano; Cicconofri, Giancarlo; Beran, Alfred; Noselli, Giovanni; DeSimone, Antonio

    2017-12-12

    The flagellar swimming of euglenids, which are propelled by a single anterior flagellum, is characterized by a generalized helical motion. The 3D nature of this swimming motion, which lacks some of the symmetries enjoyed by more common model systems, and the complex flagellar beating shapes that power it make its quantitative description challenging. In this work, we provide a quantitative, 3D, highly resolved reconstruction of the swimming trajectories and flagellar shapes of specimens of Euglena gracilis We achieved this task by using high-speed 2D image recordings taken with a conventional inverted microscope combined with a precise characterization of the helical motion of the cell body to lift the 2D data to 3D trajectories. The propulsion mechanism is discussed. Our results constitute a basis for future biophysical research on a relatively unexplored type of eukaryotic flagellar movement. Copyright © 2017 the Author(s). Published by PNAS.

  20. Flagellar glycosylation in Clostridium botulinum.

    Science.gov (United States)

    Twine, Susan M; Paul, Catherine J; Vinogradov, Evgeny; McNally, David J; Brisson, Jean-Robert; Mullen, James A; McMullin, David R; Jarrell, Harold C; Austin, John W; Kelly, John F; Logan, Susan M

    2008-09-01

    Flagellins from Clostridium botulinum were shown to be post-translationally modified with novel glycan moieties by top-down MS analysis of purified flagellin protein from strains of various toxin serotypes. Detailed analyses of flagellin from two strains of C. botulinum demonstrated that the protein is modified by a novel glycan moiety of mass 417 Da in O-linkage. Bioinformatic analysis of available C. botulinum genomes identified a flagellar glycosylation island containing homologs of genes recently identified in Campylobacter coli that have been shown to be responsible for the biosynthesis of legionaminic acid derivatives. Structural characterization of the carbohydrate moiety was completed utilizing both MS and NMR spectroscopy, and it was shown to be a novel legionaminic acid derivative, 7-acetamido-5-(N-methyl-glutam-4-yl)-amino-3,5,7,9-tetradeoxy-D-glycero-alpha-D-galacto-nonulosonic acid, (alphaLeg5GluNMe7Ac). Electron transfer dissociation MS with and without collision-activated dissociation was utilized to map seven sites of O-linked glycosylation, eliminating the need for chemical derivatization of tryptic peptides prior to analysis. Marker ions for novel glycans, as well as a unique C-terminal flagellin peptide marker ion, were identified in a top-down analysis of the intact protein. These ions have the potential for use in for rapid detection and discrimination of C. botulinum cells, indicating botulinum neurotoxin contamination. This is the first report of glycosylation of Gram-positive flagellar proteins by the 'sialic acid-like' nonulosonate sugar, legionaminic acid.

  1. Bacteria exploit a polymorphic instability of the flagellar filament to escape from traps.

    Science.gov (United States)

    Kühn, Marco J; Schmidt, Felix K; Eckhardt, Bruno; Thormann, Kai M

    2017-06-13

    Many bacterial species swim by rotating single polar helical flagella. Depending on the direction of rotation, they can swim forward or backward and change directions to move along chemical gradients but also to navigate their obstructed natural environment in soils, sediments, or mucus. When they get stuck, they naturally try to back out, but they can also resort to a radically different flagellar mode, which we discovered here. Using high-speed microscopy, we monitored the swimming behavior of the monopolarly flagellated species Shewanella putrefaciens with fluorescently labeled flagellar filaments at an agarose-glass interface. We show that, when a cell gets stuck, the polar flagellar filament executes a polymorphic change into a spiral-like form that wraps around the cell body in a spiral-like fashion and enables the cell to escape by a screw-like backward motion. Microscopy and modeling suggest that this propagation mode is triggered by an instability of the flagellum under reversal of the rotation and the applied torque. The switch is reversible and bacteria that have escaped the trap can return to their normal swimming mode by another reversal of motor direction. The screw-type flagellar arrangement enables a unique mode of propagation and, given the large number of polarly flagellated bacteria, we expect it to be a common and widespread escape or motility mode in complex and structured environments.

  2. The Flagellar Regulon of Legionella—A Review

    Science.gov (United States)

    Appelt, Sandra; Heuner, Klaus

    2017-01-01

    The Legionella genus comprises more than 60 species. In particular, Legionella pneumophila is known to cause severe illnesses in humans. Legionellaceae are ubiquitous inhabitants of aquatic environments. Some Legionellaceae are motile and their motility is important to move around in habitats. Motility can be considered as a potential virulence factor as already shown for various human pathogens. The genes of the flagellar system, regulator and structural genes, are structured in hierarchical levels described as the flagellar regulon. Their expression is modulated by various environmental factors. For L. pneumophila it was shown that the expression of genes of the flagellar regulon is modulated by the actual growth phase and temperature. Especially, flagellated Legionella are known to express genes during the transmissive phase of growth that are involved in the expression of virulence traits. It has been demonstrated that the alternative sigma-28 factor is part of the link between virulence expression and motility. In the following review, the structure of the flagellar regulon of L. pneumophila is discussed and compared to other flagellar systems of different Legionella species. Recently, it has been described that Legionella micdadei and Legionella fallonii contain a second putative partial flagellar system. Hence, the report will focus on flagellated and non-flagellated Legionella strains, phylogenetic relationships, the role and function of the alternative sigma factor (FliA) and its anti-sigma-28 factor (FlgM). PMID:29104863

  3. Coevolved Mutations Reveal Distinct Architectures for Two Core Proteins in the Bacterial Flagellar Motor.

    Directory of Open Access Journals (Sweden)

    Alessandro Pandini

    Full Text Available Switching of bacterial flagellar rotation is caused by large domain movements of the FliG protein triggered by binding of the signal protein CheY to FliM. FliG and FliM form adjacent multi-subunit arrays within the basal body C-ring. The movements alter the interaction of the FliG C-terminal (FliGC "torque" helix with the stator complexes. Atomic models based on the Salmonella entrovar C-ring electron microscopy reconstruction have implications for switching, but lack consensus on the relative locations of the FliG armadillo (ARM domains (amino-terminal (FliGN, middle (FliGM and FliGC as well as changes during chemotaxis. The generality of the Salmonella model is challenged by the variation in motor morphology and response between species. We studied coevolved residue mutations to determine the unifying elements of switch architecture. Residue interactions, measured by their coevolution, were formalized as a network, guided by structural data. Our measurements reveal a common design with dedicated switch and motor modules. The FliM middle domain (FliMM has extensive connectivity most simply explained by conserved intra and inter-subunit contacts. In contrast, FliG has patchy, complex architecture. Conserved structural motifs form interacting nodes in the coevolution network that wire FliMM to the FliGC C-terminal, four-helix motor module (C3-6. FliG C3-6 coevolution is organized around the torque helix, differently from other ARM domains. The nodes form separated, surface-proximal patches that are targeted by deleterious mutations as in other allosteric systems. The dominant node is formed by the EHPQ motif at the FliMMFliGM contact interface and adjacent helix residues at a central location within FliGM. The node interacts with nodes in the N-terminal FliGc α-helix triad (ARM-C and FliGN. ARM-C, separated from C3-6 by the MFVF motif, has poor intra-network connectivity consistent with its variable orientation revealed by structural data. ARM

  4. Inactivation of ferric uptake regulator (Fur) attenuates Helicobacter pylori J99 motility by disturbing the flagellar motor switch and autoinducer-2 production.

    Science.gov (United States)

    Lee, Ai-Yun; Kao, Cheng-Yen; Wang, Yao-Kuan; Lin, Ssu-Yuan; Lai, Tze-Ying; Sheu, Bor-Shyang; Lo, Chien-Jung; Wu, Jiunn-Jong

    2017-08-01

    Flagellar motility of Helicobacter pylori has been shown to be important for the bacteria to establish initial colonization. The ferric uptake regulator (Fur) is a global regulator that has been identified in H. pylori which is involved in the processes of iron uptake and establishing colonization. However, the role of Fur in H. pylori motility is still unclear. Motility of the wild-type, fur mutant, and fur revertant J99 were determined by a soft-agar motility assay and direct video observation. The bacterial shape and flagellar structure were evaluated by transmission electron microscopy. Single bacterial motility and flagellar switching were observed by phase-contrast microscopy. Autoinducer-2 (AI-2) production in bacterial culture supernatant was analyzed by a bioluminescence assay. The fur mutant showed impaired motility in the soft-agar assay compared with the wild-type J99 and fur revertant. The numbers and lengths of flagellar filaments on the fur mutant cells were similar to those of the wild-type and revertant cells. Phenotypic characterization showed similar swimming speed but reduction in switching rate in the fur mutant. The AI-2 production of the fur mutant was dramatically reduced compared with wild-type J99 in log-phase culture medium. These results indicate that Fur positively modulates H. pylori J99 motility through interfering with bacterial flagellar switching. © 2017 John Wiley & Sons Ltd.

  5. Emergence of flagellar beating from the collective behavior of individual ATP-powered dyneins

    OpenAIRE

    Namdeo, S.; Onck, P. R.

    2016-01-01

    Flagella are hair-like projections from the surface of eukaryotic cells, and they play an important role in many cellular functions, such as cell-motility. The beating of flagella is enabled by their internal architecture, the axoneme, and is powered by a dense distribution of motor proteins, dyneins. The dyneins deliver the required mechanical work through the hydrolysis of ATP. Although the dynein-ATP cycle, the axoneme microstructure, and the flagellar-beating kinematics are well studied, ...

  6. Crystallization and preliminary X-ray analysis of the flagellar motor `brake' molecule YcgR with c-di-GMP from Escherichia coli.

    Science.gov (United States)

    Hou, Yanjie; Li, De Feng; Wang, Da Cheng

    2013-06-01

    In Escherichia coli and Salmonella enterica, bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP), a ubiquitous bacterial second-messenger molecule that participates in many cellular processes, can regulate flagellar motor speed and reduce cell swimming velocity by binding to the PilZ-containing protein YcgR. Here, the crystallization and preliminary X-ray crystallographic analysis of YcgR with c-di-GMP are reported. The crystals diffracted to 2.3 Å resolution and belonged to space group R3:H, with unit-cell parameters a = b = 93.96, c = 109.61 Å. The asymmetric unit appeared to contain one subunit with a Matthews coefficient of 3.21 Å(3) Da(-1). The results reported here provide a sound basis for solving the crystal structure of YcgR with c-di-GMP and revealing its structure-function relationship based on the three-dimensional structure.

  7. Nonlinear amplitude dynamics in flagellar beating.

    Science.gov (United States)

    Oriola, David; Gadêlha, Hermes; Casademunt, Jaume

    2017-03-01

    The physical basis of flagellar and ciliary beating is a major problem in biology which is still far from completely understood. The fundamental cytoskeleton structure of cilia and flagella is the axoneme, a cylindrical array of microtubule doublets connected by passive cross-linkers and dynein motor proteins. The complex interplay of these elements leads to the generation of self-organized bending waves. Although many mathematical models have been proposed to understand this process, few attempts have been made to assess the role of dyneins on the nonlinear nature of the axoneme. Here, we investigate the nonlinear dynamics of flagella by considering an axonemal sliding control mechanism for dynein activity. This approach unveils the nonlinear selection of the oscillation amplitudes, which are typically either missed or prescribed in mathematical models. The explicit set of nonlinear equations are derived and solved numerically. Our analysis reveals the spatio-temporal dynamics of dynein populations and flagellum shape for different regimes of motor activity, medium viscosity and flagellum elasticity. Unstable modes saturate via the coupling of dynein kinetics and flagellum shape without the need of invoking a nonlinear axonemal response. Hence, our work reveals a novel mechanism for the saturation of unstable modes in axonemal beating.

  8. Flagellar Motility of Trypanosoma cruzi Epimastigotes

    Directory of Open Access Journals (Sweden)

    G. Ballesteros-Rodea

    2012-01-01

    Full Text Available The hemoflagellate Trypanosoma cruzi is the causative agent of American trypanosomiasis. Despite the importance of motility in the parasite life cycle, little is known about T. cruzi motility, and there is no quantitative description of its flagellar beating. Using video microscopy and quantitative vectorial analysis of epimastigote trajectories, we find a forward parasite motility defined by tip-to-base symmetrical flagellar beats. This motion is occasionally interrupted by base-to-tip highly asymmetric beats, which represent the ciliary beat of trypanosomatid flagella. The switch between flagellar and ciliary beating facilitates the parasite's reorientation, which produces a large variability of movement and trajectories that results in different distance ranges traveled by the cells. An analysis of the distance, speed, and rotational angle indicates that epimastigote movement is not completely random, and the phenomenon is highly dependent on the parasite behavior and is characterized by directed and tumbling parasite motion as well as their combination, resulting in the alternation of rectilinear and intricate motility paths.

  9. Emergence of flagellar beating from the collective behavior of individual ATP-powered dyneins

    Science.gov (United States)

    Namdeo, S.; Onck, P. R.

    2016-10-01

    Flagella are hair-like projections from the surface of eukaryotic cells, and they play an important role in many cellular functions, such as cell-motility. The beating of flagella is enabled by their internal architecture, the axoneme, and is powered by a dense distribution of motor proteins, dyneins. The dyneins deliver the required mechanical work through the hydrolysis of ATP. Although the dynein-ATP cycle, the axoneme microstructure, and the flagellar-beating kinematics are well studied, their integration into a coherent picture of ATP-powered flagellar beating is still lacking. Here we show that a time-delayed negative-work-based switching mechanism is able to convert the individual sliding action of hundreds of dyneins into a regular overall beating pattern leading to propulsion. We developed a computational model based on a minimal representation of the axoneme consisting of two representative doublet microtubules connected by nexin links. The relative sliding of the microtubules is incorporated by modeling two groups of ATP-powered dyneins, each responsible for sliding in opposite directions. A time-delayed switching mechanism is postulated, which is key in converting the local individual sliding action of multiple dyneins into global beating. Our results demonstrate that an overall nonreciprocal beating pattern can emerge with time due to the spatial and temporal coordination of the individual dyneins. These findings provide insights in the fundamental working mechanism of axonemal dyneins and could possibly open new research directions in the field of flagellar motility.

  10. An intrinsically disordered linker controlling the formation and the stability of the bacterial flagellar hook

    OpenAIRE

    Barker, Clive S.; Meshcheryakova, Irina V.; Kostyukova, Alla S.; Freddolino, Peter L.; Samatey, Fadel A.

    2017-01-01

    Background In a macro-molecular complex, any minor change may prove detrimental. For a supra-molecular nano-machine like the bacterial flagellum, which consists of several distinct parts with specific characteristics, stability is important. During the rotation of the bacterial flagellar motor, which is located in the membrane, the flagella rotate at speeds between 200 and 2000 rpm, depending on the bacterial species. The hook substructure of the bacterial flagellum acts as a universal joint ...

  11. Clinically Relevant Levels of 4-Aminopyridine Strengthen Physiological Responses in Intact Motor Circuits in Rats, Especially After Pyramidal Tract Injury.

    Science.gov (United States)

    Sindhurakar, Anil; Mishra, Asht M; Gupta, Disha; Iaci, Jennifer F; Parry, Tom J; Carmel, Jason B

    2017-04-01

    4-Aminopyridine (4-AP) is a Food and Drug Administration-approved drug to improve motor function in people with multiple sclerosis. Preliminary results suggest the drug may act on intact neural circuits and not just on demyelinated ones. To determine if 4-AP at clinically relevant levels alters the excitability of intact motor circuits. In anesthetized rats, electrodes were placed over motor cortex and the dorsal cervical spinal cord for electrical stimulation, and electromyogram electrodes were inserted into biceps muscle to measure responses. The motor responses to brain and spinal cord stimulation were measured before and for 5 hours after 4-AP administration both in uninjured rats and rats with a cut lesion of the pyramidal tract. Blood was collected at the same time as electrophysiology to determine drug plasma concentration with a goal of 20 to 100 ng/mL. We first determined that a bolus infusion of 0.32 mg/kg 4-AP was optimal: it produced on average 61.5 ± 1.8 ng/mL over the 5 hours after infusion. This dose of 4-AP increased responses to spinal cord stimulation by 1.3-fold in uninjured rats and 3-fold in rats with pyramidal tract lesion. Responses to cortical stimulation also increased by 2-fold in uninjured rats and up to 4-fold in the injured. Clinically relevant levels of 4-AP strongly augment physiological responses in intact circuits, an effect that was more robust after partial injury, demonstrating its broad potential in treating central nervous system injuries.

  12. Reactions of chicken sera to recombinant Campylobacter jejuni flagellar proteins.

    Science.gov (United States)

    Yeh, Hung-Yueh; Hiett, Kelli L; Line, John E

    2015-03-01

    Campylobacter jejuni is a Gram-negative spiral rod bacterium and is the leading but underreported bacterial food-borne pathogen that causes human campylobacteriosis worldwide. Raw or undercooked poultry products are regarded as a major source for human infection. C. jejuni flagella have been implicated in colonization and adhesion to the mucosal surface of chicken gastrointestinal tracts. Therefore, flagellar proteins would be the excellent targets for further investigation. In this report, we used the recombinant technology to generate a battery of C. jejuni flagellar proteins, which were purified by His tag affinity chromatography and determined antigenic profiles of these recombinant flagellar proteins using sera from chickens older than 6 weeks of age. The immunoblot results demonstrate that each chicken serum reacted to various numbers of recombinant flagellar proteins. Among these recombinant proteins, chicken sera reacted predominantly to the FlgE1, FlgK, FlhF, FliG and FliY proteins. These antibody screening results provide a rationale for further evaluation of these recombinant flagellar proteins as potential vaccines for chickens to improve food safety as well as investigation of host immune response to C. jejuni.

  13. Cloning, overexpression, purification, crystallization and preliminary X-ray analysis of CheY3, a response regulator that directly interacts with the flagellar ‘switch complex’ in Vibrio cholerae

    International Nuclear Information System (INIS)

    Khamrui, Susmita; Biswas, Maitree; Sen, Udayaditya; Dasgupta, Jhimli

    2010-01-01

    A chemotaxis response regulator CheY3 from V. cholerae has been cloned, overexpressed, purified and crystallized. The crystals of CheY3 diffracted to 1.86 Å resolution. Vibrio cholerae is the aetiological agent of the severe diarrhoeal disease cholera. This highly motile organism uses the processes of motility and chemotaxis to travel and colonize the intestinal epithelium. Chemotaxis in V. cholerae is far more complex than that in Escherichia coli or Salmonella typhimurium, with multiple paralogues of various chemotaxis genes. In contrast to the single copy of the chemotaxis response-regulator protein CheY in E. coli, V. cholerae contains four CheYs (CheY1–CheY4), of which CheY3 is primarily responsible for interacting with the flagellar motor protein FliM, which is one of the major constituents of the ‘switch complex’ in the flagellar motor. This interaction is the key step that controls flagellar rotation in response to environmental stimuli. CheY3 has been cloned, overexpressed and purified by Ni–NTA affinity chromatography followed by gel filtration. Crystals of CheY3 were grown in space group R3, with a calculated Matthews coefficient of 2.33 Å 3 Da −1 (47% solvent content) assuming the presence of one molecule per asymmetric unit

  14. Hierarchical protein export mechanism of the bacterial flagellar type III protein export apparatus.

    Science.gov (United States)

    Minamino, Tohru

    2018-06-01

    The bacterial flagellum is supramolecular motility machinery consisting of the basal body, the hook and the filament. Flagellar proteins are translocated across the cytoplasmic membrane via a type III protein export apparatus, diffuse down the central channel of the growing structure and assemble at the distal end. Flagellar assembly begins with the basal body, followed by the hook and finally the filament. The completion of hook assembly is the most important morphological checkpoint of the sequential flagellar assembly process. When the hook reaches its mature length of about 55 nm in Salmonella enterica, the type III protein export apparatus switches export specificity from proteins required for the structure and assembly of the hook to those responsible for filament assembly, thereby terminating hook assembly and initiating filament assembly. Three flagellar proteins, namely FliK, FlhB and FlhA, are responsible for this substrate specificity switching. Upon completion of the switching event, interactions among FlhA, the cytoplasmic ATPase complex and flagellar type III export chaperones establish the assembly order of the filament at the hook tip. Here, we describe our current understanding of a hierarchical protein export mechanism used in flagellar type III protein export.

  15. Flagellar region 3b supports strong expression of integrated DNA and the highest chromosomal integration efficiency of the Escherichia coli flagellar regions.

    Science.gov (United States)

    Juhas, Mario; Ajioka, James W

    2015-07-01

    The Gram-negative bacterium Escherichia coli is routinely used as the chassis for a variety of biotechnology and synthetic biology applications. Identification and analysis of reliable chromosomal integration and expression target loci is crucial for E. coli engineering. Chromosomal loci differ significantly in their ability to support integration and expression of the integrated genetic circuits. In this study, we investigate E. coli K12 MG1655 flagellar regions 2 and 3b. Integration of the genetic circuit into seven and nine highly conserved genes of the flagellar regions 2 (motA, motB, flhD, flhE, cheW, cheY and cheZ) and 3b (fliE, F, G, J, K, L, M, P, R), respectively, showed significant variation in their ability to support chromosomal integration and expression of the integrated genetic circuit. While not reducing the growth of the engineered strains, the integrations into all 16 target sites led to the loss of motility. In addition to high expression, the flagellar region 3b supports the highest efficiency of integration of all E. coli K12 MG1655 flagellar regions and is therefore potentially the most suitable for the integration of synthetic genetic circuits. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  16. Nanobody-Displaying Flagellar Nanotubes.

    Science.gov (United States)

    Klein, Ágnes; Kovács, Mátyás; Muskotál, Adél; Jankovics, Hajnalka; Tóth, Balázs; Pósfai, Mihály; Vonderviszt, Ferenc

    2018-02-26

    In this work we addressed the problem how to fabricate self-assembling tubular nanostructures displaying target recognition functionalities. Bacterial flagellar filaments, composed of thousands of flagellin subunits, were used as scaffolds to display single-domain antibodies (nanobodies) on their surface. As a representative example, an anti-GFP nanobody was successfully inserted into the middle part of flagellin replacing the hypervariable surface-exposed D3 domain. A novel procedure was developed to select appropriate linkers required for functional internal insertion. Linkers of various lengths and conformational properties were chosen from a linker database and they were randomly attached to both ends of an anti-GFP nanobody to facilitate insertion. Functional fusion constructs capable of forming filaments on the surface of flagellin-deficient host cells were selected by magnetic microparticles covered by target GFP molecules and appropriate linkers were identified. TEM studies revealed that short filaments of 2-900 nm were formed on the cell surface. ITC and fluorescent measurements demonstrated that the fusion protein exhibited high binding affinity towards GFP. Our approach allows the development of functionalized flagellar nanotubes against a variety of important target molecules offering potential applications in biosensorics and bio-nanotechnology.

  17. Identification and characterization of a stage specific membrane protein involved in flagellar attachment in Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Katherine Woods

    Full Text Available Flagellar attachment is a visibly striking morphological feature of African trypanosomes but little is known about the requirements for attachment at a molecular level. This study characterizes a previously undescribed membrane protein, FLA3, which plays an essential role in flagellar attachment in Trypanosoma brucei. FLA3 is heavily N-glycosylated, locates to the flagellar attachment zone and appears to be a bloodstream stage specific protein. Ablation of the FLA3 mRNA rapidly led to flagellar detachment and a concomitant failure of cytokinesis in the long slender bloodstream form but had no effect on the procyclic form. Flagellar detachment was obvious shortly after induction of the dsRNA and the newly synthesized flagellum was often completely detached after it emerged from the flagellar pocket. Within 12 h most cells possessed detached flagella alongside the existing attached flagellum. These results suggest that proteins involved in attachment are not shared between the new and old attachment zones. In other respects the detached flagella appear normal, they beat rapidly although directional motion was lost, and they possess an apparently normal axoneme and paraflagellar rod structure. The flagellar attachment zone appeared to be disrupted when FLA3 was depleted. Thus, while flagellar attachment is a constitutive feature of the life cycle of trypanosomes, attachment requires stage specific elements at the protein level.

  18. Self-Sustained Oscillatory Sliding Movement of Doublet Microtubules and Flagellar Bend Formation.

    Directory of Open Access Journals (Sweden)

    Sumio Ishijima

    Full Text Available It is well established that the basis for flagellar and ciliary movements is ATP-dependent sliding between adjacent doublet microtubules. However, the mechanism for converting microtubule sliding into flagellar and ciliary movements has long remained unresolved. The author has developed new sperm models that use bull spermatozoa divested of their plasma membrane and midpiece mitochondrial sheath by Triton X-100 and dithiothreitol. These models enable the observation of both the oscillatory sliding movement of activated doublet microtubules and flagellar bend formation in the presence of ATP. A long fiber of doublet microtubules extruded by synchronous sliding of the sperm flagella and a short fiber of doublet microtubules extruded by metachronal sliding exhibited spontaneous oscillatory movements and constructed a one beat cycle of flagellar bending by alternately actuating. The small sliding displacement generated by metachronal sliding formed helical bends, whereas the large displacement by synchronous sliding formed planar bends. Therefore, the resultant waveform is a half-funnel shape, which is similar to ciliary movements.

  19. Slipping slender bodies and enhanced flagellar locomotion

    Science.gov (United States)

    Man, Yi; Lauga, Eric

    2017-11-01

    In the biological world, many cells exploit slender appendages to swim, include numerous species of bacteria, algae and spermatozoa. A classical method to describe the flow field around such appendages is slender-body theory (SBT), which is often used to study flagellar motility in Newtonian fluids. However, biology environments are often rheologically complex due to the presence of polymers. These polymers generically phase-separate near rigid boundaries where low-viscosity fluid layers lead to effective slip on the surface. In this talk, we present an analytical derivation of SBT in the case where the no-slip boundary condition on the appendage is replaced by a Navier slip boundary condition. Our results demonstrate in particular a systematic reduction of the resistance coefficient of the slender filaments in their tangential direction, which leads to enhanced flagellar locomotion.

  20. In situ ellipsometric study of surface immobilization of flagellar filaments

    Energy Technology Data Exchange (ETDEWEB)

    Kurunczi, S., E-mail: kurunczi@mfa.kfki.hu [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Nemeth, A.; Huelber, T. [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Kozma, P. [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Department of Nanotechnology, Research Institute of Chemical and Process Engineering, Faculty of Information Technology, University of Pannonia, Egyetem u. 10, Veszprem, H-8200 (Hungary); Petrik, P. [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Jankovics, H. [Department of Nanotechnology, Research Institute of Chemical and Process Engineering, Faculty of Information Technology, University of Pannonia, Egyetem u. 10, Veszprem, H-8200 (Hungary); Sebestyen, A. [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Department of Nanotechnology, Research Institute of Chemical and Process Engineering, Faculty of Information Technology, University of Pannonia, Egyetem u. 10, Veszprem, H-8200 (Hungary); Vonderviszt, F. [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Department of Nanotechnology, Research Institute of Chemical and Process Engineering, Faculty of Information Technology, University of Pannonia, Egyetem u. 10, Veszprem, H-8200 (Hungary); Institute of Enzymology, Karolina ut 29-33, Budapest, H-1113 (Hungary); and others

    2010-10-15

    Protein filaments composed of thousands of subunits are promising candidates as sensing elements in biosensors. In this work in situ spectroscopic ellipsometry is applied to monitor the surface immobilization of flagellar filaments. This study is the first step towards the development of layers of filamentous receptors for sensor applications. Surface activation is performed using silanization and a subsequent glutaraldehyde crosslinking. Structure of the flagellar filament layers immobilized on activated and non-activated Si wafer substrates is determined using a two-layer effective medium model that accounted for the vertical density distribution of flagellar filaments with lengths of 300-1500 nm bound to the surface. The formation of the first interface layer can be explained by the multipoint covalent attachment of the filaments, while the second layer is mainly composed of tail pinned filaments floating upwards with the free parts. As confirmed by atomic force microscopy, covalent immobilization resulted in an increased surface density compared to absorption.

  1. Intraflagellar transport particle size scales inversely with flagellar length: revisiting the balance-point length control model.

    Science.gov (United States)

    Engel, Benjamin D; Ludington, William B; Marshall, Wallace F

    2009-10-05

    The assembly and maintenance of eukaryotic flagella are regulated by intraflagellar transport (IFT), the bidirectional traffic of IFT particles (recently renamed IFT trains) within the flagellum. We previously proposed the balance-point length control model, which predicted that the frequency of train transport should decrease as a function of flagellar length, thus modulating the length-dependent flagellar assembly rate. However, this model was challenged by the differential interference contrast microscopy observation that IFT frequency is length independent. Using total internal reflection fluorescence microscopy to quantify protein traffic during the regeneration of Chlamydomonas reinhardtii flagella, we determined that anterograde IFT trains in short flagella are composed of more kinesin-associated protein and IFT27 proteins than trains in long flagella. This length-dependent remodeling of train size is consistent with the kinetics of flagellar regeneration and supports a revised balance-point model of flagellar length control in which the size of anterograde IFT trains tunes the rate of flagellar assembly.

  2. In Vitro Reconstitution of Functional Type III Protein Export and Insights into Flagellar Assembly.

    Science.gov (United States)

    Terashima, Hiroyuki; Kawamoto, Akihiro; Tatsumi, Chinatsu; Namba, Keiichi; Minamino, Tohru; Imada, Katsumi

    2018-06-26

    The type III secretion system (T3SS) forms the functional core of injectisomes, protein transporters that allow bacteria to deliver virulence factors into their hosts for infection, and flagella, which are critical for many pathogens to reach the site of infection. In spite of intensive genetic and biochemical studies, the T3SS protein export mechanism remains unclear due to the difficulty of accurate measurement of protein export in vivo Here, we developed an in vitro flagellar T3S protein transport assay system using an inverted cytoplasmic membrane vesicle (IMV) for accurate and controlled measurements of flagellar protein export. We show that the flagellar T3SS in the IMV fully retains export activity. The flagellar hook was constructed inside the lumen of the IMV by adding purified component proteins externally to the IMV solution. We reproduced the hook length control and export specificity switch in the IMV consistent with that seen in the native cell. Previous in vivo analyses showed that flagellar protein export is driven by proton motive force (PMF) and facilitated by ATP hydrolysis by FliI, a T3SS-specific ATPase. Our in vitro assay recapitulated these previous in vivo observations but furthermore clearly demonstrated that even ATP hydrolysis by FliI alone can drive flagellar protein export. Moreover, this assay showed that addition of the FliH 2 /FliI complex to the assay solution at a concentration similar to that in the cell dramatically enhanced protein export, confirming that the FliH 2 /FliI complex in the cytoplasm is important for effective protein transport. IMPORTANCE The type III secretion system (T3SS) is the functional core of the injectisome, a bacterial protein transporter used to deliver virulence proteins into host cells, and bacterial flagella, critical for many pathogens. The molecular mechanism of protein transport is still unclear due to difficulties in accurate measurements of protein transport under well-controlled conditions in

  3. 3D structure of eukaryotic flagella in a quiescent state revealed by cryo-electron tomography

    Science.gov (United States)

    Nicastro, Daniela; McIntosh, J. Richard; Baumeister, Wolfgang

    2005-01-01

    We have used cryo-electron tomography to investigate the 3D structure and macromolecular organization of intact, frozen-hydrated sea urchin sperm flagella in a quiescent state. The tomographic reconstructions provide information at a resolution better than 6 nm about the in situ arrangements of macromolecules that are key for flagellar motility. We have visualized the heptameric rings of the motor domains in the outer dynein arm complex and determined that they lie parallel to the plane that contains the axes of neighboring flagellar microtubules. Both the material associated with the central pair of microtubules and the radial spokes display a plane of symmetry that helps to explain the planar beat pattern of these flagella. Cryo-electron tomography has proven to be a powerful technique for helping us understand the relationships between flagellar structure and function and the design of macromolecular machines in situ. PMID:16246999

  4. Minimum Information Loss Based Multi-kernel Learning for Flagellar Protein Recognition in Trypanosoma Brucei

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-12-01

    Trypanosma brucei (T. Brucei) is an important pathogen agent of African trypanosomiasis. The flagellum is an essential and multifunctional organelle of T. Brucei, thus it is very important to recognize the flagellar proteins from T. Brucei proteins for the purposes of both biological research and drug design. In this paper, we investigate computationally recognizing flagellar proteins in T. Brucei by pattern recognition methods. It is argued that an optimal decision function can be obtained as the difference of probability functions of flagella protein and the non-flagellar protein for the purpose of flagella protein recognition. We propose to learn a multi-kernel classification function to approximate this optimal decision function, by minimizing the information loss of such approximation which is measured by the Kull back-Leibler (KL) divergence. An iterative multi-kernel classifier learning algorithm is developed to minimize the KL divergence for the problem of T. Brucei flagella protein recognition, experiments show its advantage over other T. Brucei flagellar protein recognition and multi-kernel learning methods. © 2014 IEEE.

  5. Role of calmodulin and calcineurin in regulating flagellar motility and wave polarity in Leishmania.

    Science.gov (United States)

    Mukhopadhyay, Aakash Gautam; Dey, Chinmoy Sankar

    2017-11-01

    We have previously reported the involvement of cyclic AMP in regulating flagellar waveforms in Leishmania. Here, we investigated the roles of calcium, calmodulin, and calcineurin in flagellar motility regulation in L. donovani. Using high-speed videomicroscopy, we show that calcium-independent calmodulin and calcineurin activity is necessary for motility in Leishmania. Inhibition of calmodulin and calcineurin induced ciliary beats interrupting flagellar beating in both live (in vivo) and ATP-reactivated (in vitro) parasites. Our results indicate that signaling mediated by calmodulin and calcineurin operates antagonistically to cAMP signaling in regulating the waveforms of Leishmania flagellum. These two pathways are possibly involved in maintaining the balance between the two waveforms, essential for responding to environmental cues, survival, and infectivity.

  6. The flagellar master operon flhDC is a pleiotropic regulator involved in motility and virulence of the fish pathogen Yersinia ruckeri.

    Science.gov (United States)

    Jozwick, A K S; Graf, J; Welch, T J

    2017-03-01

    To investigate the function of the master flagellar operon flhDC in the fish pathogen Yersinia ruckeri and compare the effect of a constructed flhD mutation to a naturally occurring fliR mutation causing loss-of-motility in emergent biotype 2 (BT2) strains. Yersinia ruckeri flhD and fliR mutants were constructed in a motile strain. Both mutations caused loss-of-motility, ablation of flagellin synthesis and phospholipase secretion, similar to naturally occurring BT2 strains. Transcriptome analysis confirmed flhDC regulation of flagellar, chemotaxis and phospholipase loci as well as other genes of diverse function. The flhD mutation confers a competitive advantage within the fish host when compared with its parent strain, while this advantage was not seen with the naturally occurring fliR mutation. An intact flhD is necessary for expression of the flagellar secretion system as well as other diverse loci, consistent with a role for flhD as a pleiotropic regulator. The maintenance of the flhD locus in Y. ruckeri strains suggests its importance for aspects of Y. ruckeri biology other than virulence, since the flhD mutation conferred a competitive advantage during experimental challenge of rainbow trout. Yersinia ruckeri is the causative agent of enteric red mouth disease, an invasive septicaemia that affects farmed salmonid fish species. Disease outbreaks can cause severe economic losses in aquaculture. BT2 variants, which have independently emerged worldwide, are an increasing threat to farmed fish production. Knowledge of mechanisms involved in virulence, conserved functions and gene regulation among strains may be exploited for the development of novel disease control strategies to prevent pathogen growth or virulence phenotypes within aquaculture. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  7. Chlamydomonas IFT25 is dispensable for flagellar assembly but required to export the BBSome from flagella

    Directory of Open Access Journals (Sweden)

    Bin Dong

    2017-11-01

    Full Text Available Intraflagellar transport (IFT particles are composed of polyprotein complexes IFT-A and IFT-B as well as cargo adaptors such as the BBSome. Two IFT-B subunits, IFT25 and IFT27 were found to form a heterodimer, which is essential in exporting the BBSome out of the cilium but not involved in flagellar assembly and cytokinesis in vertebrates. Controversial results were, however, recorded to show that defects in IFT, flagellar assembly and even cytokinesis were caused by IFT27 knockdown in Chlamydomonas reinhardtii. Using C. reinhardtii as a model organism, we report that depletion of IFT25 has no effect on flagellar assembly and does not affect the entry of the BBSome into the flagellum, but IFT25 depletion did impair BBSome movement out of the flagellum, clarifying the evolutionally conserved role of IFT25 in regulating the exit of the BBSome from the flagellum cross species. Interestingly, depletion of IFT25 causes dramatic reduction of IFT27 as expected, which does not cause defects in flagellar assembly and cytokinesis in C. reinhardtii. Our data thus support that Chlamydomonas IFT27, like its vertebrate homologues, is not involved in flagellar assembly and cytokinesis.

  8. Changes in the flagellar bundling time account for variations in swimming behavior of flagellated bacteria in viscous media

    Science.gov (United States)

    Qu, Zijie; Temel, Fatma; Henderikx, Rene; Breuer, Kenneth

    2017-11-01

    The motility of bacteria E.coli in viscous fluids has been widely studied, although conflicting results on the effect of viscosity on swimming speed abound. The swimming mode of wild-type E.coli is idealized as a run-and-tumble sequence in which periods of straight swimming at a constant speed are randomly interrupted by a tumble, defined as a sudden change of direction with a very low speed. Using a tracking microscope, we follow cells for extended time and find that the swimming behavior of a single cell can exhibit a variety of behaviors including run-and-tumble and ``slow-random-walk'' in which the cells move at relatively low speed without the characteristic run. Although the characteristic swimming speed varies between individuals and in different polymer solutions, we find that the skewness of the speed distribution is solely a function of viscosity, and uniquely determines the ratio of the average speed to the characteristic run speed. Using Resistive Force Theory and the cell-specific measured characteristic run speed, we show that differences in the swimming behavior observed in solutions of different viscosity are due to changes in the flagellar bundling time, which increases as the viscosity rises, due to lower rotation rate of the flagellar motor. National Science Foundation.

  9. The Bacterial Flagellar Type III Export Gate Complex Is a Dual Fuel Engine That Can Use Both H+ and Na+ for Flagellar Protein Export.

    Directory of Open Access Journals (Sweden)

    Tohru Minamino

    2016-03-01

    Full Text Available The bacterial flagellar type III export apparatus utilizes ATP and proton motive force (PMF to transport flagellar proteins to the distal end of the growing flagellar structure for self-assembly. The transmembrane export gate complex is a H+-protein antiporter, of which activity is greatly augmented by an associated cytoplasmic ATPase complex. Here, we report that the export gate complex can use sodium motive force (SMF in addition to PMF across the cytoplasmic membrane to drive protein export. Protein export was considerably reduced in the absence of the ATPase complex and a pH gradient across the membrane, but Na+ increased it dramatically. Phenamil, a blocker of Na+ translocation, inhibited protein export. Overexpression of FlhA increased the intracellular Na+ concentration in the presence of 100 mM NaCl but not in its absence, suggesting that FlhA acts as a Na+ channel. In wild-type cells, however, neither Na+ nor phenamil affected protein export, indicating that the Na+ channel activity of FlhA is suppressed by the ATPase complex. We propose that the export gate by itself is a dual fuel engine that uses both PMF and SMF for protein export and that the ATPase complex switches this dual fuel engine into a PMF-driven export machinery to become much more robust against environmental changes in external pH and Na+ concentration.

  10. The Bacterial Flagellar Type III Export Gate Complex Is a Dual Fuel Engine That Can Use Both H+ and Na+ for Flagellar Protein Export.

    Science.gov (United States)

    Minamino, Tohru; Morimoto, Yusuke V; Hara, Noritaka; Aldridge, Phillip D; Namba, Keiichi

    2016-03-01

    The bacterial flagellar type III export apparatus utilizes ATP and proton motive force (PMF) to transport flagellar proteins to the distal end of the growing flagellar structure for self-assembly. The transmembrane export gate complex is a H+-protein antiporter, of which activity is greatly augmented by an associated cytoplasmic ATPase complex. Here, we report that the export gate complex can use sodium motive force (SMF) in addition to PMF across the cytoplasmic membrane to drive protein export. Protein export was considerably reduced in the absence of the ATPase complex and a pH gradient across the membrane, but Na+ increased it dramatically. Phenamil, a blocker of Na+ translocation, inhibited protein export. Overexpression of FlhA increased the intracellular Na+ concentration in the presence of 100 mM NaCl but not in its absence, suggesting that FlhA acts as a Na+ channel. In wild-type cells, however, neither Na+ nor phenamil affected protein export, indicating that the Na+ channel activity of FlhA is suppressed by the ATPase complex. We propose that the export gate by itself is a dual fuel engine that uses both PMF and SMF for protein export and that the ATPase complex switches this dual fuel engine into a PMF-driven export machinery to become much more robust against environmental changes in external pH and Na+ concentration.

  11. Architecture of the flagellar apparatus and related structures in the type species of Peridinium, P. cinctum (Dinophyceae)

    DEFF Research Database (Denmark)

    Calado, A.C.; Hansen, Gert; Moestrup, Øjvind

    1999-01-01

    The ultrastructure of Peridinium cinctum, was examined by serial sectioning with particular emphasis on the detailed construction of the flagellar apparatus. The pusular system of P. cinctum included two sac pusules in open connection with the flagellar canals; disorganized material was found ins...

  12. Porters versus rowers: a unified stochastic model of motor proteins.

    Science.gov (United States)

    Leibler, S; Huse, D A

    1993-06-01

    We present a general phenomenological theory for chemical to mechanical energy transduction by motor enzymes which is based on the classical "tight-coupling" mechanism. The associated minimal stochastic model takes explicitly into account both ATP hydrolysis and thermal noise effects. It provides expressions for the hydrolysis rate and the sliding velocity, as functions of the ATP concentration and the number of motor enzymes. It explains in a unified way many results of recent in vitro motility assays. More importantly, the theory provides a natural classification scheme for the motors: it correlates the biochemical and mechanical differences between "porters" such as cellular kinesins or dyneins, and "rowers" such as muscular myosins or flagellar dyneins.

  13. Flagellar apparatus and nuclear chambers of the green dinoflagellate Gymnodinium chlorophorum

    DEFF Research Database (Denmark)

    Hansen, Gert; Moestrup, Øjvind

    2005-01-01

    The green dinoflagellate Gymnodinium chlorophorum (BAH ME 100, the type culture) was reexamined with emphasis on the structure of the flagellar apparatus and nuclear envelope. Like other Gymnodinium species, G. chlorophorum possessed a nuclear fibrous connective linking the flagellar apparatus...... present in G. chlorophorum similar to those reported in Gymnodinium aureolum and Gymnodinium nolleri. In contrast to the type species of Gymnodinium, Gymnodinium fuscum, only one nuclear pore was present per chamber. The presence of a feeding tube (peduncle) suggests that G. chlorophorum is mixotrophic....... Although the fine structure of G. chlorophorum revealed its affiliation to the Gymnodinium group the above discrepancies set it apart, indicating that it might belong in a different genus....

  14. Bacterial flagellar capping proteins adopt diverse oligomeric states

    Energy Technology Data Exchange (ETDEWEB)

    Postel, Sandra; Deredge, Daniel; Bonsor, Daniel A.; Yu, Xiong; Diederichs, Kay; Helmsing, Saskia; Vromen, Aviv; Friedler, Assaf; Hust, Michael; Egelman, Edward H.; Beckett, Dorothy; Wintrode, Patrick L.; Sundberg, Eric J. (UV); (Braunschweig); (Maryland-MED); (Konstanz); (Maryland); (Hebrew)

    2016-09-24

    Flagella are crucial for bacterial motility and pathogenesis. The flagellar capping protein (FliD) regulates filament assembly by chaperoning and sorting flagellin (FliC) proteins after they traverse the hollow filament and exit the growing flagellum tip. In the absence of FliD, flagella are not formed, resulting in impaired motility and infectivity. Here, we report the 2.2 Å resolution X-ray crystal structure of FliD fromPseudomonas aeruginosa, the first high-resolution structure of any FliD protein from any bacterium. Using this evidence in combination with a multitude of biophysical and functional analyses, we find thatPseudomonasFliD exhibits unexpected structural similarity to other flagellar proteins at the domain level, adopts a unique hexameric oligomeric state, and depends on flexible determinants for oligomerization. Considering that the flagellin filaments on which FliD oligomers are affixed vary in protofilament number between bacteria, our results suggest that FliD oligomer stoichiometries vary across bacteria to complement their filament assemblies.

  15. Crystallographic and molecular dynamics analysis of loop motions unmasking the peptidoglycan-binding site in stator protein MotB of flagellar motor.

    Directory of Open Access Journals (Sweden)

    Cyril F Reboul

    Full Text Available BACKGROUND: The C-terminal domain of MotB (MotB-C shows high sequence similarity to outer membrane protein A and related peptidoglycan (PG-binding proteins. It is believed to anchor the power-generating MotA/MotB stator unit of the bacterial flagellar motor to the peptidoglycan layer of the cell wall. We previously reported the first crystal structure of this domain and made a puzzling observation that all conserved residues that are thought to be essential for PG recognition are buried and inaccessible in the crystal structure. In this study, we tested a hypothesis that peptidoglycan binding is preceded by, or accompanied by, some structural reorganization that exposes the key conserved residues. METHODOLOGY/PRINCIPAL FINDINGS: We determined the structure of a new crystalline form (Form B of Helicobacter pylori MotB-C. Comparisons with the existing Form A revealed conformational variations in the petal-like loops around the carbohydrate binding site near one end of the β-sheet. These variations are thought to reflect natural flexibility at this site required for insertion into the peptidoglycan mesh. In order to understand the nature of this flexibility we have performed molecular dynamics simulations of the MotB-C dimer. The results are consistent with the crystallographic data and provide evidence that the three loops move in a concerted fashion, exposing conserved MotB residues that have previously been implicated in binding of the peptide moiety of peptidoglycan. CONCLUSION/SIGNIFICANCE: Our structural analysis provides a new insight into the mechanism by which MotB inserts into the peptidoglycan mesh, thus anchoring the power-generating complex to the cell wall.

  16. Human sperm steer with second harmonics of the flagellar beat.

    Science.gov (United States)

    Saggiorato, Guglielmo; Alvarez, Luis; Jikeli, Jan F; Kaupp, U Benjamin; Gompper, Gerhard; Elgeti, Jens

    2017-11-10

    Sperm are propelled by bending waves traveling along their flagellum. For steering in gradients of sensory cues, sperm adjust the flagellar waveform. Symmetric and asymmetric waveforms result in straight and curved swimming paths, respectively. Two mechanisms causing spatially asymmetric waveforms have been proposed: an average flagellar curvature and buckling. We image flagella of human sperm tethered with the head to a surface. The waveform is characterized by a fundamental beat frequency and its second harmonic. The superposition of harmonics breaks the beat symmetry temporally rather than spatially. As a result, sperm rotate around the tethering point. The rotation velocity is determined by the second-harmonic amplitude and phase. Stimulation with the female sex hormone progesterone enhances the second-harmonic contribution and, thereby, modulates sperm rotation. Higher beat frequency components exist in other flagellated cells; therefore, this steering mechanism might be widespread and could inspire the design of synthetic microswimmers.

  17. Nonlinear instability in flagellar dynamics: a novel modulation mechanism in sperm migration?

    KAUST Repository

    Gadelha, H.; Gaffney, E. A.; Smith, D. J.; Kirkman-Brown, J. C.

    2010-01-01

    . We study the effect of geometrical nonlinearity, focusing on the spermatozoon flagellum. For a wide range of physiologically relevant parameters, the nonlinear model predicts that flagellar compression by the internal forces initiates an effective

  18. Identification of flagellar motility genes in Yersinia ruckeri by transposon mutagenesis

    DEFF Research Database (Denmark)

    Evenhuis, Jason P:; LaPatra, Scott E.; Verner-Jeffreys, David W.

    2009-01-01

    Here we demonstrate that flagellar secretion is required for production of secreted lipase activity in the fish pathogen Yersinia ruckeri and that neither of these activities is necessary for virulence in rainbow trout. Our results suggest a possible mechanism for the emergence of nonmotile biotype...

  19. Genetical and functional investigation of fliC genes encoding flagellar serotype H4 in wildtype strains of Escherichia coli and in a laboratory E. coli K-12 strain expressing flagellar antigen type H48

    Directory of Open Access Journals (Sweden)

    Schaudinn Christoph

    2005-01-01

    Full Text Available Abstract Background Serotyping of O-(lipopolysaccharide and H-(flagellar antigens is a wideley used method for identification of pathogenic strains and clones of Escherichia coli. At present, 176 O- and 53 H-antigens are described for E. coli which occur in different combinations in the strains. The flagellar antigen H4 is widely present in E. coli strains of different O-serotypes and pathotypes and we have investigated the genetic relationship between H4 encoding fliC genes by PCR, nucleotide sequencing and expression studies. Results The complete nucleotide sequence of fliC genes present in E. coli reference strains U9-41 (O2:K1:H4 and P12b (O15:H17 was determined and both were found 99.3% (1043 of 1050 nucleotides identical in their coding sequence. A PCR/RFLP protocol was developed for typing of fliC-H4 strains and 88 E. coli strains reacting with H4 antiserum were investigated. Nucleotide sequencing of complete fliC genes of six E. coli strains which were selected based on serum agglutination titers, fliC-PCR genotyping and reference data revealed 96.6 to 100% identity on the amino acid level. The functional expression of flagellin encoded by fliC-H4 from strain U9-41 and from our strain P12b which is an H4 expressing variant type was investigated in the E. coli K-12 strain JM109 which encodes flagellar type H48. The fliC recombinant plasmid carrying JM109 strains reacted with both H4 and H48 specific antisera whereas JM109 reacted only with the H48 antiserum. By immunoelectron microscopy, we could show that the flagella made by the fliC-H4 recombinant plasmid carrying strain are constituted of H48 and H4 flagellins which are co-assembled into functional flagella. Conclusion The flagellar serotype H4 is encoded by closely related fliC genes present in serologically different types of E. coli strainswhich were isolated at different time periods and geographical locations. Our expression studies show for the first time, that flagellins of

  20. Ultrastructure of the harmful unarmored dinoflagellate Cochlodinium polykrikoides (Dinophyceae) with reference to the apical groove and Flagellar apparatus.

    Science.gov (United States)

    Iwataki, Mitsunori; Hansen, Gert; Moestrup, Øjvind; Matsuoka, Kazumi

    2010-01-01

    The external and internal ultrastructure of the harmful unarmored dinoflagellate Cochlodinium polykrikoides Margalef has been examined with special reference to the apical groove and three-dimensional structure of the flagellar apparatus. The apical groove is U-shaped and connected to the anterior sulcal extension on the dorsal side of the epicone. The eyespot is located dorsally and composed of two layers of globules situated within the chloroplast. A narrow invagination of the plasma membrane is associated with the eyespot. The nuclear envelope has normal nuclear pores similar to other eukaryotes but different from the Gymnodinium group with diagnostic nuclear chambers. The longitudinal and transverse basal bodies are separated by approximately 0.5-1.0 microm and interconnected directly by a striated basal body connective and indirectly by microtubular and fibrous structures. Characteristic features of the flagellar apparatus are as follows: (1) a nuclear extension projects to the R1 (longitudinal microtubular root) and is connected to the root by thin fibrous material; (2) fibrillar structures are associated with the longitudinal and transverse flagellar canal; and (3) a striated ventral connective extends toward the posterior end of the cell along the longitudinal flagellar canal. We conclude, based on both morphological and molecular evidence, that Cochlodinium is only distantly related to Gymnodinium.

  1. Induction of phospholipase- and flagellar synthesis in Serratia liquefaciens is controlled by expression of the flagellar master operon flhD

    DEFF Research Database (Denmark)

    Givskov, M; Eberl, L; Christiansen, Gunna

    1995-01-01

    When a liquid culture of Serratia spp. reaches the last part of the logarithmic phase of growth it induces the synthesis of several extracellular hydrolytic enzymes. In this communication we show that synthesis and secretion of the extracellular phospholipase is coupled to expression of flagella....... Expression of flagella is demonstrated to follow a growth-phase-dependent pattern. Cloning, complementation studies and DNA-sequencing analysis has identified a genetic region in Serratia liquefaciens which exhibits extensive homology to the Escherichia coli flhD flagellar master operon. Interruption...

  2. Induction of phospholipase- and flagellar synthesis in Serratia liquefaciens is controlled by expression of the flagellar master operon flhD

    DEFF Research Database (Denmark)

    Givskov, M; Eberl, L; Christiansen, Gunna

    1995-01-01

    . Expression of flagella is demonstrated to follow a growth-phase-dependent pattern. Cloning, complementation studies and DNA-sequencing analysis has identified a genetic region in Serratia liquefaciens which exhibits extensive homology to the Escherichia coli flhD flagellar master operon. Interruption...... of the chromosomal flhD operon in S. liquefaciens results in non-flagellated and phospholipase-negative cells, but the synthesis of other exoenzymes is not affected. By placing the flhD operon under the control of a foreign inducible promoter we have shown that increased transcription through the flhD operon leads...

  3. Tetrameric structure of the flagellar cap protein FliD from Serratia marcescens.

    Science.gov (United States)

    Cho, So Yeon; Song, Wan Seok; Hong, Ho Jeong; Lee, Geun-Shik; Kang, Seung Goo; Ko, Hyun-Jeong; Kim, Pyeung-Hyeun; Yoon, Sung-Il

    2017-07-15

    Bacterial motility is provided by the flagellum. FliD is located at the distal end of the flagellum and plays a key role in the insertion of each flagellin protein at the growing tip of the flagellar filament. Because FliD functions as an oligomer, the determination of the oligomeric state of FliD is critical to understanding the molecular mechanism of FliD-mediated flagellar growth. FliD has been shown to adopt a pentameric or a hexameric structure depending on the bacterial species. Here, we report another distinct oligomeric form of FliD based on structural and biochemical studies. The crystal structures of the D2 and D3 domains of Serratia marcescens FliD (smFliD) were determined in two crystal forms and together revealed that smFliD assembles into a tetrameric architecture that resembles a four-pointed star plate. smFliD tetramerization was also confirmed in solution by cross-linking experiments. Although smFliD oligomerizes in a head-to-tail orientation using a common primary binding interface between the D2 and D3' domains (the prime denotes the second subunit in the oligomer) similarly to other FliD orthologs, the smFliD tetramer diverges to present a unique secondary D2-D2' binding interface. Our structure-based comparative analysis of FliD suggests that bacteria have developed diverse species-specific oligomeric forms of FliD that range from tetramers to hexamers for flagellar growth. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Flagellar-phase variation: isolation of the rh1 gene

    International Nuclear Information System (INIS)

    Silverman, M.; Zieg, J.; Simon, M.

    1979-01-01

    In Salmonella, expression of flagellar antigen alternates between two serotypes (phases) encoded by two genes, H1 and H2. The mechanism which controls the alternative expression of the H1 and H2 genes was examined by cloning these genes and the genetic elements which control their activity on hybrid vehicles in Escherichia coli. H2 gene activity was shown to be controlled by a recombinational switch located adjacent to the H2 gene. Activity of the H1 gene is thought to be repressed, when the H2 gene is expressed, by the product of another gene, rhl (repressor of H1), which is controlled coordinately with the H2 gene. In this report, we describe the construction of hybrid lambda vehicles which contain, in addition to the H2 gene, a genetic activity corresponding to rhl. Variation of flagellar antigens analogous to that observed in Salmonella was observed when E. coli strains were transduced with the hybrid lambda. By using the lambda H2rhl hybrid to program protein syntheis in uv-irradiated cells, the synthesis of a polypeptide was correlated with rhl gene product activity. We conclude that the H2 region consists of two cotranscribed genes, H2 and rhl. The expression of both gene products is regulated by the same recombinational event

  5. Flagellar filament bio-templated inorganic oxide materials - towards an efficient lithium battery anode.

    Science.gov (United States)

    Beznosov, Sergei N; Veluri, Pavan S; Pyatibratov, Mikhail G; Chatterjee, Abhijit; MacFarlane, Douglas R; Fedorov, Oleg V; Mitra, Sagar

    2015-01-13

    Designing a new generation of energy-intensive and sustainable electrode materials for batteries to power a variety of applications is an imperative task. The use of biomaterials as a nanosized structural template for these materials has the potential to produce hitherto unachievable structures. In this report, we have used genetically modified flagellar filaments of the extremely halophilic archaea species Halobacterium salinarum to synthesize nanostructured iron oxide composites for use as a lithium-ion battery anode. The electrode demonstrated a superior electrochemical performance compared to existing literature results, with good capacity retention of 1032 mAh g(-1) after 50 cycles and with high rate capability, delivering 770 mAh g(-1) at 5 A g(-1) (~5 C) discharge rate. This unique flagellar filament based template has the potential to provide access to other highly structured advanced energy materials in the future.

  6. Variation in motor output and motor performance in a centrally generated motor pattern

    Science.gov (United States)

    Norris, Brian J.; Doloc-Mihu, Anca; Calabrese, Ronald L.

    2014-01-01

    Central pattern generators (CPGs) produce motor patterns that ultimately drive motor outputs. We studied how functional motor performance is achieved, specifically, whether the variation seen in motor patterns is reflected in motor performance and whether fictive motor patterns differ from those in vivo. We used the leech heartbeat system in which a bilaterally symmetrical CPG coordinates segmental heart motor neurons and two segmented heart tubes into two mutually exclusive coordination modes: rear-to-front peristaltic on one side and nearly synchronous on the other, with regular side-to-side switches. We assessed individual variability of the motor pattern and the beat pattern in vivo. To quantify the beat pattern we imaged intact adults. To quantify the phase relations between motor neurons and heart constrictions we recorded extracellularly from two heart motor neurons and movement from the corresponding heart segments in minimally dissected leeches. Variation in the motor pattern was reflected in motor performance only in the peristaltic mode, where larger intersegmental phase differences in the motor neurons resulted in larger phase differences between heart constrictions. Fictive motor patterns differed from those in vivo only in the synchronous mode, where intersegmental phase differences in vivo had a larger front-to-rear bias and were more constrained. Additionally, load-influenced constriction timing might explain the amplification of the phase differences between heart segments in the peristaltic mode and the higher variability in motor output due to body shape assumed in this soft-bodied animal. The motor pattern determines the beat pattern, peristaltic or synchronous, but heart mechanics influence the phase relations achieved. PMID:24717348

  7. The phylogeny of swimming kinematics: The environment controls flagellar waveforms in sperm motility

    Science.gov (United States)

    Guasto, Jeffrey; Burton, Lisa; Zimmer, Richard; Hosoi, Anette; Stocker, Roman

    2013-11-01

    In recent years, phylogenetic and molecular analyses have dominated the study of ecology and evolution. However, physical interactions between organisms and their environment, a fundamental determinant of organism ecology and evolution, are mediated by organism form and function, highlighting the need to understand the mechanics of basic survival strategies, including locomotion. Focusing on spermatozoa, we combined high-speed video microscopy and singular value decomposition analysis to quantitatively compare the flagellar waveforms of eight species, ranging from marine invertebrates to humans. We found striking similarities in sperm swimming kinematics between genetically dissimilar organisms, which could not be uncovered by phylogenetic analysis. The emergence of dominant waveform patterns across species are suggestive of biological optimization for flagellar locomotion and point toward environmental cues as drivers of this convergence. These results reinforce the power of quantitative kinematic analysis to understand the physical drivers of evolution and as an approach to uncover new solutions for engineering applications, such as micro-robotics.

  8. Deduction of upstream sequences of Xanthomonas campestris flagellar genes responding to transcription activation by FleQ

    International Nuclear Information System (INIS)

    Hu, R.-M.; Yang, T.-C.; Yang, S.-H.; Tseng, Y.-H.

    2005-01-01

    Xanthomonas campestris pv. campestris (Xcc), a close relative to Pseudomonas aeruginosa, is the pathogen causing black rot in cruciferous plants. In P. aeruginosa, FleQ serves as a cognate activator of σ 54 in transcription from several σ 54 -dependent promoters of flagellar genes. These P. aeruginosa promoters have been analyzed for FleQ-binding sequences; however, no consensus was deduced. Xcc, although lacks fleSR, has a fleQ homologue residing among over 40 contiguously clustered flagellar genes. A fleQ mutant, Xc17fleQ, constructed by insertional mutation is deficient in FleQ protein, non-flagellated, and immobile. Transcriptional fusion assays on six putative σ 54 -dependent promoters of the flagellar genes, fliE, fliQ, fliL, flgG, flgB, and flhF, indicated that each of them is also FleQ dependent. Each of these promoters has a sequence with weak consensus to 5'-gaaacCCgccgCcgctTt-3', immediately upstream of the predicted σ 54 -binding site, with an imperfect inverted repeat containing a GC-rich center flanked by several A and T at 5'- and 3'-ends, respectively. Replacing this region in fliE promoter with a HindIII recognition sequence abolished the transcription, indicating that this region responds to transcription activation by FleQ

  9. Minimum Information Loss Based Multi-kernel Learning for Flagellar Protein Recognition in Trypanosoma Brucei

    KAUST Repository

    Wang, Jim Jing-Yan; Gao, Xin

    2014-01-01

    for the purposes of both biological research and drug design. In this paper, we investigate computationally recognizing flagellar proteins in T. Brucei by pattern recognition methods. It is argued that an optimal decision function can be obtained as the difference

  10. Flagellar filament bio-templated inorganic oxide materials – towards an efficient lithium battery anode

    Science.gov (United States)

    Beznosov, Sergei N.; Veluri, Pavan S.; Pyatibratov, Mikhail G.; Chatterjee, Abhijit; MacFarlane, Douglas R.; Fedorov, Oleg V.; Mitra, Sagar

    2015-01-01

    Designing a new generation of energy-intensive and sustainable electrode materials for batteries to power a variety of applications is an imperative task. The use of biomaterials as a nanosized structural template for these materials has the potential to produce hitherto unachievable structures. In this report, we have used genetically modified flagellar filaments of the extremely halophilic archaea species Halobacterium salinarum to synthesize nanostructured iron oxide composites for use as a lithium-ion battery anode. The electrode demonstrated a superior electrochemical performance compared to existing literature results, with good capacity retention of 1032 mAh g−1 after 50 cycles and with high rate capability, delivering 770 mAh g−1 at 5 A g−1 (~5 C) discharge rate. This unique flagellar filament based template has the potential to provide access to other highly structured advanced energy materials in the future. PMID:25583370

  11. CRIS-a novel cAMP-binding protein controlling spermiogenesis and the development of flagellar bending.

    Directory of Open Access Journals (Sweden)

    Anke Miriam Krähling

    Full Text Available The second messengers cAMP and cGMP activate their target proteins by binding to a conserved cyclic nucleotide-binding domain (CNBD. Here, we identify and characterize an entirely novel CNBD-containing protein called CRIS (cyclic nucleotide receptor involved in sperm function that is unrelated to any of the other members of this protein family. CRIS is exclusively expressed in sperm precursor cells. Cris-deficient male mice are either infertile due to a lack of sperm resulting from spermatogenic arrest, or subfertile due to impaired sperm motility. The motility defect is caused by altered Ca(2+ regulation of flagellar beat asymmetry, leading to a beating pattern that is reminiscent of sperm hyperactivation. Our results suggest that CRIS interacts during spermiogenesis with Ca(2+-regulated proteins that--in mature sperm--are involved in flagellar bending.

  12. Association of Lis1 with outer arm dynein is modulated in response to alterations in flagellar motility

    Science.gov (United States)

    Rompolas, Panteleimon; Patel-King, Ramila S.; King, Stephen M.

    2012-01-01

    The cytoplasmic dynein regulatory factor Lis1, which induces a persistent tight binding to microtubules and allows for transport of cargoes under high-load conditions, is also present in motile cilia/flagella. We observed that Lis1 levels in flagella of Chlamydomonas strains that exhibit defective motility due to mutation of various axonemal substructures were greatly enhanced compared with wild type; this increase was absolutely dependent on the presence within the flagellum of the outer arm dynein α heavy chain/light chain 5 thioredoxin unit. To assess whether cells might interpret defective motility as a “high-load environment,” we reduced the flagellar beat frequency of wild-type cells through enhanced viscous load and by reductive stress; both treatments resulted in increased levels of flagellar Lis1, which altered the intrinsic beat frequency of the trans flagellum. Differential extraction of Lis1 from wild-type and mutant axonemes suggests that the affinity of outer arm dynein for Lis1 is directly modulated. In cytoplasm, Lis1 localized to two punctate structures, one of which was located near the base of the flagella. These data reveal that the cell actively monitors motility and dynamically modulates flagellar levels of the dynein regulatory factor Lis1 in response to imposed alterations in beat parameters. PMID:22855525

  13. Nonlinear instability in flagellar dynamics: a novel modulation mechanism in sperm migration?

    KAUST Repository

    Gadelha, H.

    2010-05-12

    Throughout biology, cells and organisms use flagella and cilia to propel fluid and achieve motility. The beating of these organelles, and the corresponding ability to sense, respond to and modulate this beat is central to many processes in health and disease. While the mechanics of flagellum-fluid interaction has been the subject of extensive mathematical studies, these models have been restricted to being geometrically linear or weakly nonlinear, despite the high curvatures observed physiologically. We study the effect of geometrical nonlinearity, focusing on the spermatozoon flagellum. For a wide range of physiologically relevant parameters, the nonlinear model predicts that flagellar compression by the internal forces initiates an effective buckling behaviour, leading to a symmetry-breaking bifurcation that causes profound and complicated changes in the waveform and swimming trajectory, as well as the breakdown of the linear theory. The emergent waveform also induces curved swimming in an otherwise symmetric system, with the swimming trajectory being sensitive to head shape-no signalling or asymmetric forces are required. We conclude that nonlinear models are essential in understanding the flagellar waveform in migratory human sperm; these models will also be invaluable in understanding motile flagella and cilia in other systems.

  14. Flagellar motility confers epiphytic fitness advantages upon Pseudomonas syringae

    International Nuclear Information System (INIS)

    Haefele, D.M.; Lindow, S.E.

    1987-01-01

    The role of flagellar motility in determining the epiphytic fitness of an ice-nucleation-active strain of Pseudomonas syringae was examined. The loss of flagellar motility reduced the epiphytic fitness of a normally motile P. syringae strain as measured by its growth, survival, and competitive ability on bean leaf surfaces. Equal population sizes of motile parental or nonmotile mutant P. syringae strains were maintained on bean plants for at least 5 days following the inoculation of fully expanded primary leaves. However, when bean seedlings were inoculated before the primary leaves had expanded and bacterial populations on these leaves were quantified at full expansion, the population size of the nonmotile derivative strain reached only 0.9% that of either the motile parental or revertant strain. When fully expanded bean primary leaves were coinoculated with equal numbers of motile and nonmotile cells, the population size of a nonmotile derivative strain was one-third of that of the motile parental or revertant strain after 8 days. Motile and nonmotile cells were exposed in vitro and on plants to UV radiation and desiccating conditions. The motile and nonmotile strains exhibited equal resistance to both stresses in vitro. However, the population size of a nonmotile strain on leaves was less than 20% that of a motile revertant strain when sampled immediately after UV irradiation. Epiphytic populations of both motile and nonmotile P. syringae declined under desiccating conditions on plants, and after 8 days, the population size of a nonmotile strain was less than one-third that of the motile parental or revertant strain

  15. Testing the time-of-flight model for flagellar length sensing.

    Science.gov (United States)

    Ishikawa, Hiroaki; Marshall, Wallace F

    2017-11-07

    Cilia and flagella are microtubule-based organelles that protrude from the surface of most cells, are important to the sensing of extracellular signals, and make a driving force for fluid flow. Maintenance of flagellar length requires an active transport process known as intraflagellar transport (IFT). Recent studies reveal that the amount of IFT injection negatively correlates with the length of flagella. These observations suggest that a length-dependent feedback regulates IFT. However, it is unknown how cells recognize the length of flagella and control IFT. Several theoretical models try to explain this feedback system. We focused on one of the models, the "time-of-flight" model, which measures the length of flagella on the basis of the travel time of IFT protein in the flagellar compartment. We tested the time-of-flight model using Chlamydomonas dynein mutant cells, which show slower retrograde transport speed. The amount of IFT injection in dynein mutant cells was higher than that in control cells. This observation does not support the prediction of the time-of-flight model and suggests that Chlamydomonas uses another length-control feedback system rather than that described by the time-of-flight model. © 2017 Ishikawa and Marshall. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  16. Trypanin, a component of the flagellar Dynein regulatory complex, is essential in bloodstream form African trypanosomes.

    Directory of Open Access Journals (Sweden)

    Katherine S Ralston

    2006-09-01

    Full Text Available The Trypanosoma brucei flagellum is a multifunctional organelle with critical roles in motility, cellular morphogenesis, and cell division. Although motility is thought to be important throughout the trypanosome lifecycle, most studies of flagellum structure and function have been restricted to the procyclic lifecycle stage, and our knowledge of the bloodstream form flagellum is limited. We have previously shown that trypanin functions as part of a flagellar dynein regulatory system that transmits regulatory signals from the central pair apparatus and radial spokes to axonemal dyneins. Here we investigate the requirement for this dynein regulatory system in bloodstream form trypanosomes. We demonstrate that trypanin is localized to the flagellum of bloodstream form trypanosomes, in a pattern identical to that seen in procyclic cells. Surprisingly, trypanin RNA interference is lethal in the bloodstream form. These knockdown mutants fail to initiate cytokinesis, but undergo multiple rounds of organelle replication, accumulating multiple flagella, nuclei, kinetoplasts, mitochondria, and flagellum attachment zone structures. These findings suggest that normal flagellar beat is essential in bloodstream form trypanosomes and underscore the emerging concept that there is a dichotomy between trypanosome lifecycle stages with respect to factors that contribute to cell division and cell morphogenesis. This is the first time that a defined dynein regulatory complex has been shown to be essential in any organism and implicates the dynein regulatory complex and other enzymatic regulators of flagellar motility as candidate drug targets for the treatment of African sleeping sickness.

  17. The MogR Transcriptional Repressor Regulates Nonhierarchal Expression of Flagellar Motility Genes and Virulence in Listeria monocytogenes.

    Directory of Open Access Journals (Sweden)

    2006-04-01

    Full Text Available Flagella are surface structures critical for motility and virulence of many bacterial species. In Listeria monocytogenes, MogR tightly represses expression of flagellin (FlaA during extracellular growth at 37 degrees C and during intracellular infection. MogR is also required for full virulence in a murine model of infection. Using in vitro and in vivo infection models, we determined that the severe virulence defect of MogR-negative bacteria is due to overexpression of FlaA. Specifically, overproduction of FlaA in MogR-negative bacteria caused pleiotropic defects in bacterial division (chaining phenotype, intracellular spread, and virulence in mice. DNA binding and microarray analyses revealed that MogR represses transcription of all known flagellar motility genes by binding directly to a minimum of two TTTT-N(5-AAAA recognition sites positioned within promoter regions such that RNA polymerase binding is occluded. Analysis of MogR protein levels demonstrated that modulation of MogR repression activity confers the temperature-specificity to flagellar motility gene expression. Epistasis analysis revealed that MogR repression of transcription is antagonized in a temperature-dependent manner by the DegU response regulator and that DegU further regulates FlaA levels through a posttranscriptional mechanism. These studies provide the first known example to our knowledge of a transcriptional repressor functioning as a master regulator controlling nonhierarchal expression of flagellar motility genes.

  18. Rab23 is a flagellar protein in Trypanosoma brucei

    Directory of Open Access Journals (Sweden)

    Field Mark C

    2011-06-01

    Full Text Available Abstract Background Rab small GTPases are important mediators of membrane transport, and orthologues frequently retain similar locations and functions, even between highly divergent taxa. In metazoan organisms Rab23 is an important negative regulator of Sonic hedgehog signaling and is crucial for correct development and differentiation of cellular lineages by virtue of an involvement in ciliary recycling. Previously, we reported that Trypanosoma brucei Rab23 localized to the nuclear envelope 1, which is clearly inconsistent with the mammalian location and function. As T. brucei is unicellular the potential that Rab23 has no role in cell signaling was possible. Here we sought to further investigate the role(s of Rab23 in T. brucei to determine if Rab23 was an example of a Rab protein with divergent function in distinct taxa. Methods/major findings The taxonomic distribution of Rab23 was examined and compared with the presence of flagella/cilia in representative taxa. Despite evidence for considerable secondary loss, we found a clear correlation between a conventional flagellar structure and the presence of a Rab23 orthologue in the genome. By epitope-tagging, Rab23 was localized and found to be present at the flagellum throughout the cell cycle. However, RNAi knockdown did not result in a flagellar defect, suggesting that Rab23 is not required for construction or maintenance of the flagellum. Conclusions The location of Rab23 at the flagellum is conserved between mammals and trypanosomes and the Rab23 gene is restricted to flagellated organisms. These data may suggest the presence of a Rab23-mediated signaling mechanism in trypanosomes.

  19. Autonomously responsive pumping by a bacterial flagellar forest: A mean-field approach

    Science.gov (United States)

    Martindale, James D.; Fu, Henry C.

    2017-09-01

    This study is motivated by a microfluidic device that imparts a magnetic torque on an array of bacterial flagella. Bacterial flagella can transform their helical geometry autonomously in response to properties of the background fluid, which provides an intriguing mechanism allowing their use as an engineered element for the regulation or transport of chemicals in microscale applications. The synchronization of flagellar phase has been widely studied in biological contexts, but here we examine the synchronization of flagellar tilt, which is necessary for effective pumping. We first examine the effects of helical geometry and tilt on the pumping flows generated by a single rotating flagellum. Next, we explore a mean-field model for an array of helical flagella to understand how collective tilt arises and influences pumping. The mean-field methodology allows us to take into account possible phase differences through a time-averaging procedure and to model an infinite array of flagella. We find array separation distances, magnetic field strengths, and rotation frequencies that produce nontrivial self-consistent pumping solutions. For individual flagella, pumping is reversed when helicity or rotation is reversed; in contrast, when collective effects are included, self-consistent tilted pumping solutions become untilted nonpumping solutions when helicity or rotation is reversed.

  20. Protein export through the bacterial flagellar type III export pathway.

    Science.gov (United States)

    Minamino, Tohru

    2014-08-01

    For construction of the bacterial flagellum, which is responsible for bacterial motility, the flagellar type III export apparatus utilizes both ATP and proton motive force across the cytoplasmic membrane and exports flagellar proteins from the cytoplasm to the distal end of the nascent structure. The export apparatus consists of a membrane-embedded export gate made of FlhA, FlhB, FliO, FliP, FliQ, and FliR and a water-soluble ATPase ring complex consisting of FliH, FliI, and FliJ. FlgN, FliS, and FliT act as substrate-specific chaperones that do not only protect their cognate substrates from degradation and aggregation in the cytoplasm but also efficiently transfer the substrates to the export apparatus. The ATPase ring complex facilitates the initial entry of the substrates into the narrow pore of the export gate. The export gate by itself is a proton-protein antiporter that uses the two components of proton motive force, the electric potential difference and the proton concentration difference, for different steps of the export process. A specific interaction of FlhA with FliJ located in the center of the ATPase ring complex allows the export gate to efficiently use proton motive force to drive protein export. The ATPase ring complex couples ATP binding and hydrolysis to its assembly-disassembly cycle for rapid and efficient protein export cycle. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey. © 2013 Elsevier B.V. All rights reserved.

  1. Electrical Stimulation of Motor Cortex in the Uninjured Hemisphere after Chronic Unilateral Injury Promotes Recovery of Skilled Locomotion through Ipsilateral Control

    OpenAIRE

    Carmel, Jason B.; Kimura, Hiroki; Martin, John H.

    2014-01-01

    Partial injury to the corticospinal tract (CST) causes sprouting of intact axons at their targets, and this sprouting correlates with functional improvement. Electrical stimulation of motor cortex augments sprouting of intact CST axons and promotes functional recovery when applied soon after injury. We hypothesized that electrical stimulation of motor cortex in the intact hemisphere after chronic lesion of the CST in the other hemisphere would restore function through ipsilateral control. To ...

  2. Transmitter-controlled properties of α-motoneurones causing long-lasting motor discharge to brief excitatory inputs

    DEFF Research Database (Denmark)

    Hounsgaard, J.; Hultborn, H.; Kiehn, O.

    1986-01-01

    Brief sensory inputs to intact conscious subjects commonly trigger complex long-lasting motor responses, in which higher cerebral mechanisms, or even voluntary action, may be integrative parts. However, long-lasting motor discharge following brief afferent stimulation is also observed in reduced ...... flipflops, which are set at one of two levels by short excitatory or inhibitory inputs. However, when the whole motoneuronal pool is considered, many different levels can be maintained by recruitment of new units.......Brief sensory inputs to intact conscious subjects commonly trigger complex long-lasting motor responses, in which higher cerebral mechanisms, or even voluntary action, may be integrative parts. However, long-lasting motor discharge following brief afferent stimulation is also observed in reduced...

  3. Curcumin Reduces the Motility of Salmonella enterica Serovar Typhimurium by Binding to the Flagella, Thereby Leading to Flagellar Fragility and Shedding

    Science.gov (United States)

    Balakrishnan, Arjun; Negi, Vidya Devi; Sakorey, Deepika; Chandra, Nagasuma

    2016-01-01

    ABSTRACT One of the important virulence properties of the pathogen is its ability to travel to a favorable environment, cross the viscous mucus barrier (intestinal barrier for enteric pathogens), and reach the epithelia to initiate pathogenesis with the help of an appendage, like flagella. Nonetheless, flagella can act as an “Achilles heel,” revealing the pathogen's presence to the host through the stimulation of innate and adaptive immune responses. We assessed whether curcumin, a dietary polyphenol, could alter the motility of Salmonella, a foodborne pathogen. It reduced the motility of Salmonella enterica serovar Typhimurium by shortening the length of the flagellar filament (from ∼8 μm to ∼5 μm) and decreasing its density (4 or 5 flagella/bacterium instead of 8 or 9 flagella/bacterium). Upon curcumin treatment, the percentage of flagellated bacteria declined from ∼84% to 59%. However, no change was detected in the expression of the flagellin gene and protein. A fluorescence binding assay demonstrated binding of curcumin to the flagellar filament. This might make the filament fragile, breaking it into smaller fragments. Computational analysis predicted the binding of curcumin, its analogues, and its degraded products to a flagellin molecule at an interface between domains D1 and D2. Site-directed mutagenesis and a fluorescence binding assay confirmed the binding of curcumin to flagellin at residues ASN120, ASP123, ASN163, SER164, ASN173, and GLN175. IMPORTANCE This work, to our knowledge the first report of its kind, examines how curcumin targets flagellar density and affects the pathogenesis of bacteria. We found that curcumin does not affect any of the flagellar synthesis genes. Instead, it binds to the flagellum and makes it fragile. It increases the torsional stress on the flagellar filament that then breaks, leaving fewer flagella around the bacteria. Flagella, which are crucial ligands for Toll-like receptor 5, are some of the most important

  4. Microscopic Analysis of Bacterial Motility at High Pressure

    Science.gov (United States)

    Nishiyama, Masayoshi; Sowa, Yoshiyuki

    2012-01-01

    The bacterial flagellar motor is a molecular machine that converts an ion flux to the rotation of a helical flagellar filament. Counterclockwise rotation of the filaments allows them to join in a bundle and propel the cell forward. Loss of motility can be caused by environmental factors such as temperature, pH, and solvation. Hydrostatic pressure is also a physical inhibitor of bacterial motility, but the detailed mechanism of this inhibition is still unknown. Here, we developed a high-pressure microscope that enables us to acquire high-resolution microscopic images, regardless of applied pressures. We also characterized the pressure dependence of the motility of swimming Escherichia coli cells and the rotation of single flagellar motors. The fraction and speed of swimming cells decreased with increased pressure. At 80 MPa, all cells stopped swimming and simply diffused in solution. After the release of pressure, most cells immediately recovered their initial motility. Direct observation of the motility of single flagellar motors revealed that at 80 MPa, the motors generate torque that should be sufficient to join rotating filaments in a bundle. The discrepancy in the behavior of free swimming cells and individual motors could be due to the applied pressure inhibiting the formation of rotating filament bundles that can propel the cell body in an aqueous environment. PMID:22768943

  5. Neural activation differences in amputees during imitation of intact versus amputee movements

    Directory of Open Access Journals (Sweden)

    William F Cusack

    2012-06-01

    Full Text Available The mirror neuron system has been attributed with increased activation in motor-related cortical areas upon viewing of another’s actions. Recent work suggests that limb movements that are similar and dissimilar in appearance to that of the viewer equivalently activate the mirror neuron system. It is unclear if this result can be observed in the action encoding areas in amputees who use prosthetic devices. Intact subjects and upper extremity amputee prosthesis users were recruited to view video demonstrations of tools being used by an intact actor and a prosthetic device user. All subjects were asked to pantomime the movements seen in the video while recording electroencephalography. Intact subjects showed equivalent left parietofrontal activity during imitation after watching the intact or prosthetic arm. Likewise, when prosthesis users imitated prosthesis demonstrations, typical left parietofrontal activation was observed during planning. When prosthesis users imitated intact actors, a new pattern was revealed which showed greater bilateral parietal and occipital activity during movement planning (p<0.001. This change may be required for prosthesis users to imitate movements in which the limb states between the observed and the observer do not match. The finding that prosthesis users imitating other prosthesis users showed typical left parietofrontal activation suggests that these subjects engage normal planning related activity when they are able to imitate a limb matching their own. This result has significant implications on rehabilitation, as standard therapy involves training with an intact occupational therapist, which could necessitate atypical planning mechanisms in amputees when learning to use their prosthesis.

  6. Auditory-Motor Interactions in Pediatric Motor Speech Disorders: Neurocomputational Modeling of Disordered Development

    Science.gov (United States)

    Terband, H.; Maassen, B.; Guenther, F.H.; Brumberg, J.

    2014-01-01

    Background/Purpose Differentiating the symptom complex due to phonological-level disorders, speech delay and pediatric motor speech disorders is a controversial issue in the field of pediatric speech and language pathology. The present study investigated the developmental interaction between neurological deficits in auditory and motor processes using computational modeling with the DIVA model. Method In a series of computer simulations, we investigated the effect of a motor processing deficit alone (MPD), and the effect of a motor processing deficit in combination with an auditory processing deficit (MPD+APD) on the trajectory and endpoint of speech motor development in the DIVA model. Results Simulation results showed that a motor programming deficit predominantly leads to deterioration on the phonological level (phonemic mappings) when auditory self-monitoring is intact, and on the systemic level (systemic mapping) if auditory self-monitoring is impaired. Conclusions These findings suggest a close relation between quality of auditory self-monitoring and the involvement of phonological vs. motor processes in children with pediatric motor speech disorders. It is suggested that MPD+APD might be involved in typically apraxic speech output disorders and MPD in pediatric motor speech disorders that also have a phonological component. Possibilities to verify these hypotheses using empirical data collected from human subjects are discussed. PMID:24491630

  7. Electrical stimulation of motor cortex in the uninjured hemisphere after chronic unilateral injury promotes recovery of skilled locomotion through ipsilateral control.

    Science.gov (United States)

    Carmel, Jason B; Kimura, Hiroki; Martin, John H

    2014-01-08

    Partial injury to the corticospinal tract (CST) causes sprouting of intact axons at their targets, and this sprouting correlates with functional improvement. Electrical stimulation of motor cortex augments sprouting of intact CST axons and promotes functional recovery when applied soon after injury. We hypothesized that electrical stimulation of motor cortex in the intact hemisphere after chronic lesion of the CST in the other hemisphere would restore function through ipsilateral control. To test motor skill, rats were trained and tested to walk on a horizontal ladder with irregularly spaced rungs. Eight weeks after injury, produced by pyramidal tract transection, half of the rats received forelimb motor cortex stimulation of the intact hemisphere. Rats with injury and stimulation had significantly improved forelimb control compared with rats with injury alone and achieved a level of proficiency similar to uninjured rats. To test whether recovery of forelimb function was attributable to ipsilateral control, we selectively inactivated the stimulated motor cortex using the GABA agonist muscimol. The dose of muscimol we used produces strong contralateral but no ipsilateral impairments in naive rats. In rats with injury and stimulation, but not those with injury alone, inactivation caused worsening of forelimb function; the initial deficit was reinstated. These results demonstrate that electrical stimulation can promote recovery of motor function when applied late after injury and that motor control can be exerted from the ipsilateral motor cortex. These results suggest that the uninjured motor cortex could be targeted for brain stimulation in people with large unilateral CST lesions.

  8. Recruitment of rat diaphragm motor units across motor behaviors with different levels of diaphragm activation.

    Science.gov (United States)

    Seven, Yasin B; Mantilla, Carlos B; Sieck, Gary C

    2014-12-01

    Phrenic motor neurons are recruited across a range of motor behaviors to generate varying levels of diaphragm muscle (DIAm) force. We hypothesized that DIAm motor units are recruited in a fixed order across a range of motor behaviors of varying force levels, consistent with the Henneman Size Principle. Single motor unit action potentials and compound DIAm EMG activities were recorded in anesthetized, neurally intact rats across different motor behaviors, i.e., eupnea, hypoxia-hypercapnia (10% O2 and 5% CO2), deep breaths, sustained airway occlusion, and sneezing. Central drive [estimated by root-mean-squared (RMS) EMG value 75 ms after the onset of EMG activity (RMS75)], recruitment delay, and onset discharge frequencies were similar during eupnea and hypoxia-hypercapnia. Compared with eupnea, central drive increased (∼25%) during deep breaths, and motor units were recruited ∼12 ms earlier (P motor units were recruited ∼30 ms earlier (P motor unit onset discharge frequencies were significantly higher (P Recruitment order of motor unit pairs observed during eupnea was maintained for 98%, 87%, and 84% of the same pairs recorded during hypoxia-hypercapnia, deep breaths, and airway occlusion, respectively. Reversals in motor unit recruitment order were observed primarily if motor unit pairs were recruited motor unit recruitment order being determined primarily by the intrinsic size-dependent electrophysiological properties of phrenic motor neurons. Copyright © 2014 the American Physiological Society.

  9. Assembly and stoichiometry of the core structure of the bacterial flagellar type III export gate complex.

    Science.gov (United States)

    Fukumura, Takuma; Makino, Fumiaki; Dietsche, Tobias; Kinoshita, Miki; Kato, Takayuki; Wagner, Samuel; Namba, Keiichi; Imada, Katsumi; Minamino, Tohru

    2017-08-01

    The bacterial flagellar type III export apparatus, which is required for flagellar assembly beyond the cell membranes, consists of a transmembrane export gate complex and a cytoplasmic ATPase complex. FlhA, FlhB, FliP, FliQ, and FliR form the gate complex inside the basal body MS ring, although FliO is required for efficient export gate formation in Salmonella enterica. However, it remains unknown how they form the gate complex. Here we report that FliP forms a homohexameric ring with a diameter of 10 nm. Alanine substitutions of conserved Phe-137, Phe-150, and Glu-178 residues in the periplasmic domain of FliP (FliPP) inhibited FliP6 ring formation, suppressing flagellar protein export. FliO formed a 5-nm ring structure with 3 clamp-like structures that bind to the FliP6 ring. The crystal structure of FliPP derived from Thermotoga maritia, and structure-based photo-crosslinking experiments revealed that Phe-150 and Ser-156 of FliPP are involved in the FliP-FliP interactions and that Phe-150, Arg-152, Ser-156, and Pro-158 are responsible for the FliP-FliO interactions. Overexpression of FliP restored motility of a ∆fliO mutant to the wild-type level, suggesting that the FliP6 ring is a functional unit in the export gate complex and that FliO is not part of the final gate structure. Copurification assays revealed that FlhA, FlhB, FliQ, and FliR are associated with the FliO/FliP complex. We propose that the assembly of the export gate complex begins with FliP6 ring formation with the help of the FliO scaffold, followed by FliQ, FliR, and FlhB and finally FlhA during MS ring formation.

  10. Mechanism of gastrointestinal abnormal motor activity induced by cisplatin in conscious dogs.

    Science.gov (United States)

    Ando, Hiroyuki; Mochiki, Erito; Ohno, Tetsuro; Yanai, Mitsuhiro; Toyomasu, Yoshitaka; Ogata, Kyoichi; Tabe, Yuichi; Aihara, Ryuusuke; Nakabayashi, Toshihiro; Asao, Takayuki; Kuwano, Hiroyuki

    2014-11-14

    To investigate whether 5-hydroxytryptamine (serotonin; 5-HT) is involved in mediating abnormal motor activity in dogs after cisplatin administration. After the dogs had been given a 2-wk recovery period, all of them were administered cisplatin, and the motor activity was recorded using strain gauge force transducers. Blood and intestinal fluid samples were collected to measure 5-HT for 24 h. To determine whether 5-HT in plasma or that in intestinal fluids is more closely related to abnormal motor activity we injected 5-HT into the bloodstream and the intestinal tract of the dogs. Cisplatin given intravenously produced abnormal motor activity that lasted up to 5 h. From 3 to 4 h after cisplatin administration, normal intact dogs exhibited retropropagation of motor activity accompanied by emesis. The concentration of 5-HT in plasma reached the peak at 4 h, and that in intestinal fluids reached the peak at 3 h. In normal intact dogs with resection of the vagus nerve that were administered kytril, cisplatin given intravenously did not produce abnormal motor activity. Intestinal serotonin administration did not produce abnormal motor activity, but intravenous serotonin administration did. After the intravenous administration of cisplatin, abnormal motor activity was produced in the involved vagus nerve and in the involved serotonergic neurons via another pathway. This study was the first to determine the relationship between 5-HT and emesis-induced motor activity.

  11. Nicotinic acetylcholine receptor density in cognitively intact subjects at an early stage of Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Ioannis Ugo eIsaias

    2014-08-01

    Full Text Available We investigated in vivo brain nicotinic acetylcholine receptor (nAChR distribution in cognitively intact subjects with Parkinson's disease (PD at an early stage of the disease. Fourteen patients and 13 healthy subjects were imaged with single photon emission computed tomography (SPECT and the radiotracer 5-[123I]iodo-3-[2(S-2-azetidinylmethoxy]pyridine ([123I]5IA. Patients were selected according to several criteria, including short duration of motor signs (<7 years and normal scores at an extensive neuropsychological evaluation. In PD patients, nAChR density was significantly higher in the putamen, the insular cortex and the supplementary motor area and lower in the caudate nucleus, the orbitofrontal cortex and the middle temporal gyrus. Disease duration positively correlated with nAChR density in the putamen ipsilateral (ρ=0.56, p<0.05 but not contralateral (ρ=0.49, p=0.07 to the clinically most affected hemibody.We observed, for the first time in vivo, higher nAChR density in brain regions of the motor and limbic basal ganglia circuits of subjects with PD. Our findings support the notion of an up-regulated cholinergic activity at the striatal and possibly cortical level in cognitively intact PD patients at an early stage of disease.

  12. Polymorphic transformation of helical flagella of bacteria

    Science.gov (United States)

    Lim, Sookkyung; Howard Berg Collaboration; William Ko Collaboration; Yongsam Kim Collaboration; Wanho Lee Collaboration; Charles Peskin Collaboration

    2016-11-01

    Bacteria such as E. coli swim in an aqueous environment by utilizing the rotation of flagellar motors and alternate two modes of motility, runs and tumbles. Runs are steady forward swimming driven by bundles of flagellar filaments whose motors are turning CCW; tumbles involve a reorientation of the direction of swimming triggered by motor reversals. During tumbling, the helical flagellum undergoes polymorphic transformations, which is a local change in helical pitch, helical radius, and handedness. In this work, we investigate the underlying mechanism of structural conformation and how this polymorphic transition plays a role in bacterial swimming. National Science Foundation.

  13. Motor skills of children with autistic spectrum disorder

    Directory of Open Access Journals (Sweden)

    Zikl Pavel

    2016-01-01

    Full Text Available The contribution contains results of a research of motor skills of children with autistic spectrum disorder. The group of children represents besides major triad of symptoms, also described difficulties in the field of motor skills. Our aim to find out what motor skills of these children are in comparison with intact population and what differences are found in individual motor items, i.e. in fine motor skills, gross motor skills and in balance. The data was gained with the use of standardized Movement Assessment Battery test for Children 2 (MABC-2. Objective testing of this group of children is relatively difficult. There were successfully tested 36 children with ASD during this phase of research. The research demonstrated evident motor disorder at 86% of children in the observed sample. Statistically significant were worse results in the field of fine motor skills compared to the results in gross motor skills and balance.

  14. Are there intracellular Ca2+ oscillations correlated with flagellar beating in human sperm? A three vs. two-dimensional analysis.

    Science.gov (United States)

    Corkidi, G; Montoya, F; Hernández-Herrera, P; Ríos-Herrera, W A; Müller, M F; Treviño, C L; Darszon, A

    2017-09-01

    Are there intracellular Ca2+ ([Ca2+]i) oscillations correlated with flagellar beating in human sperm? The results reveal statistically significant [Ca2+]i oscillations that are correlated with the human sperm flagellar beating frequency, when measured in three-dimensions (3D). Fast [Ca2+]i oscillations that are correlated to the beating flagellar frequency of cells swimming in a restricted volume have been detected in hamster sperm. To date, such findings have not been confirmed in any other mammalian sperm species. An important question that has remained regarding these observations is whether the fast [Ca2+]i oscillations are real or might they be due to remaining defocusing effects of the Z component arising from the 3D beating of the flagella. Healthy donors whose semen samples fulfill the WHO criteria between the age of 18-28 were selected. Cells from at least six different donors were utilized for analysis. Approximately the same number of experimental and control cells were analyzed. Motile cells were obtained by the swim-up technique and were loaded with Fluo-4 (Ca2+ sensitive dye) or with Calcein (Ca2+ insensitive dye). Ni2+ was used as a non-specific plasma membrane Ca2+ channel blocker. Fluorescence data and flagella position were acquired in 3D. Each cell was recorded for up to 5.6 s within a depth of 16 microns with a high speed camera (coupled to an image intensifier) acquiring at a rate of 3000 frames per second, while an oscillating objective vibrated at 90 Hz via a piezoelectric device. From these samples, eight experimental and nine control sperm cells were analyzed in both 2D and 3D. We have implemented a new system that allows [Ca2+]i measurements of the human sperm flagellum beating in 3D. These measurements reveal statistically significant [Ca2+]i oscillations that correlate with the flagellar beating frequency. These oscillations may arise from intracellular sources and/or Ca2+ transporters, as they were insensitive to external Ni2+, a non

  15. Extensive flagellar remodeling during the complex life cycle of &ITParatrypanosoma&IT, an early-branching trypanosomatid

    Czech Academy of Sciences Publication Activity Database

    Skalický, Tomáš; Dobáková, Eva; Wheeler, R. J.; Tesařová, Martina; Flegontov, P.; Jirsová, Dagmar; Votýpka, Jan; Yurchenko, V.; Ayala, F. J.; Lukeš, Julius

    2017-01-01

    Roč. 114, č. 44 (2017), s. 11757-11762 ISSN 0027-8424 R&D Projects: GA ČR(CZ) GA14-23986S; GA MŠk LL1601; GA MŠk(CZ) LM2015062 Institutional support: RVO:60077344 Keywords : trypanosomatid * evolution * flagellar remodeling * haptomonads * cytostome Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biology (theoretical, mathematical, thermal, cryobiology, biological rhythm), Evolutionary biology Impact factor: 9.661, year: 2016

  16. The Neuronal Network Orchestration behind Motor Behaviors

    DEFF Research Database (Denmark)

    Petersen, Peter Christian

    to motoneurons during rhythmic motor behaviors, and specifically the hypothesis that motoneurons receive concurrent excitatory and inhibitory (E/I) inputs. Berg et al. (2007) presented the concurrent hypothesis, which goes against the classical feed forward reciprocal model for spinal motor networks that has...... gained widespread acceptance. We developed an adult turtle preparation where the spinal motor network was intact, which also allowed us to perform intracellular recordings from motoneurons during rhythmic motor activity. We estimated the synaptic excitatory and inhibitory conductances by two individual...... (Buzsáki and Mizuseki, 2014). Roxin et al. (2011) detailed the firing rate distribution in networks in the balanced regime, and found it to be similar to a lognormal distribution and describing the data from the population studies very well. Our experimental observations and analysis are in agreement...

  17. Combined motor cortex and spinal cord neuromodulation promotes corticospinal system functional and structural plasticity and motor function after injury.

    Science.gov (United States)

    Song, Weiguo; Amer, Alzahraa; Ryan, Daniel; Martin, John H

    2016-03-01

    An important strategy for promoting voluntary movements after motor system injury is to harness activity-dependent corticospinal tract (CST) plasticity. We combine forelimb motor cortex (M1) activation with co-activation of its cervical spinal targets in rats to promote CST sprouting and skilled limb movement after pyramidal tract lesion (PTX). We used a two-step experimental design in which we first established the optimal combined stimulation protocol in intact rats and then used the optimal protocol in injured animals to promote CST repair and motor recovery. M1 was activated epidurally using an electrical analog of intermittent theta burst stimulation (iTBS). The cervical spinal cord was co-activated by trans-spinal direct current stimulation (tsDCS) that was targeted to the cervical enlargement, simulated from finite element method. In intact rats, forelimb motor evoked potentials (MEPs) were strongly facilitated during iTBS and for 10 min after cessation of stimulation. Cathodal, not anodal, tsDCS alone facilitated MEPs and also produced a facilitatory aftereffect that peaked at 10 min. Combined iTBS and cathodal tsDCS (c-tsDCS) produced further MEP enhancement during stimulation, but without further aftereffect enhancement. Correlations between forelimb M1 local field potentials and forelimb electromyogram (EMG) during locomotion increased after electrical iTBS alone and further increased with combined stimulation (iTBS+c-tsDCS). This optimized combined stimulation was then used to promote function after PTX because it enhanced functional connections between M1 and spinal circuits and greater M1 engagement in muscle contraction than either stimulation alone. Daily application of combined M1 iTBS on the intact side and c-tsDCS after PTX (10 days, 27 min/day) significantly restored skilled movements during horizontal ladder walking. Stimulation produced a 5.4-fold increase in spared ipsilateral CST terminations. Combined neuromodulation achieves optimal motor

  18. Progressive motor cortex functional reorganization following 6-hydroxydopamine lesioning in rats.

    Science.gov (United States)

    Viaro, Riccardo; Morari, Michele; Franchi, Gianfranco

    2011-03-23

    Many studies have attempted to correlate changes of motor cortex activity with progression of Parkinson's disease, although results have been controversial. In the present study we used intracortical microstimulation (ICMS) combined with behavioral testing in 6-hydroxydopamine hemilesioned rats to evaluate the impact of dopamine depletion on movement representations in primary motor cortex (M1) and motor behavior. ICMS allows for motor-effective stimulation of corticofugal neurons in motor areas so as to obtain topographic movements representations based on movement type, area size, and threshold currents. Rats received unilateral 6-hydroxydopamine in the nigrostriatal bundle, causing motor impairment. Changes in M1 were time dependent and bilateral, although stronger in the lesioned than the intact hemisphere. Representation size and threshold current were maximally impaired at 15 d, although inhibition was still detectable at 60-120 d after lesion. Proximal forelimb movements emerged at the expense of the distal ones. Movement lateralization was lost mainly at 30 d after lesion. Systemic L-3,4-dihydroxyphenylalanine partially attenuated motor impairment and cortical changes, particularly in the caudal forelimb area, and completely rescued distal forelimb movements. Local application of the GABA(A) antagonist bicuculline partially restored cortical changes, particularly in the rostral forelimb area. The local anesthetic lidocaine injected into the M1 of the intact hemisphere restored movement lateralization in the lesioned hemisphere. This study provides evidence for motor cortex remodeling after unilateral dopamine denervation, suggesting that cortical changes were associated with dopamine denervation, pathogenic intracortical GABA inhibition, and altered interhemispheric activity.

  19. The Lipid Raft Proteome of African Trypanosomes Contains Many Flagellar Proteins.

    Science.gov (United States)

    Sharma, Aabha I; Olson, Cheryl L; Engman, David M

    2017-08-24

    Lipid rafts are liquid-ordered membrane microdomains that form by preferential association of 3-β-hydroxysterols, sphingolipids and raft-associated proteins often having acyl modifications. We isolated lipid rafts of the protozoan parasite Trypanosoma brucei and determined the protein composition of lipid rafts in the cell. This analysis revealed a striking enrichment of flagellar proteins and several putative signaling proteins in the lipid raft proteome. Calpains and intraflagellar transport proteins, in particular, were found to be abundant in the lipid raft proteome. These findings provide additional evidence supporting the notion that the eukaryotic cilium/flagellum is a lipid raft-enriched specialized structure with high concentrations of sterols, sphingolipids and palmitoylated proteins involved in environmental sensing and cell signaling.

  20. Ultrastructure of the harmful unarmored dinoflagellate Cochlodinium polykrikoides (Dinophyceae) with reference to the apical groove and flagellar apparatus

    DEFF Research Database (Denmark)

    Iwataki, Mitsunori; Hansen, Gert; Moestrup, Øjvind

    2010-01-01

    The external and internal ultrastructure of the harmful unarmored dinoflagellate Cochlodinium polykrikoides Margalef has been examined with special reference to the apical groove and three-dimensional structure of the flagellar apparatus. The apical groove is U-shaped and connected to the anterior...

  1. Evidence for loss of a partial flagellar glycolytic pathway during trypanosomatid evolution.

    Directory of Open Access Journals (Sweden)

    Robert W B Brown

    Full Text Available Classically viewed as a cytosolic pathway, glycolysis is increasingly recognized as a metabolic pathway exhibiting surprisingly wide-ranging variations in compartmentalization within eukaryotic cells. Trypanosomatid parasites provide an extreme view of glycolytic enzyme compartmentalization as several glycolytic enzymes are found exclusively in peroxisomes. Here, we characterize Trypanosoma brucei flagellar proteins resembling glyceraldehyde-3-phosphate dehydrogenase (GAPDH and phosphoglycerate kinase (PGK: we show the latter associates with the axoneme and the former is a novel paraflagellar rod component. The paraflagellar rod is an essential extra-axonemal structure in trypanosomes and related protists, providing a platform into which metabolic activities can be built. Yet, bioinformatics interrogation and structural modelling indicate neither the trypanosome PGK-like nor the GAPDH-like protein is catalytically active. Orthologs are present in a free-living ancestor of the trypanosomatids, Bodo saltans: the PGK-like protein from B. saltans also lacks key catalytic residues, but its GAPDH-like protein is predicted to be catalytically competent. We discuss the likelihood that the trypanosome GAPDH-like and PGK-like proteins constitute molecular evidence for evolutionary loss of a flagellar glycolytic pathway, either as a consequence of niche adaptation or the re-localization of glycolytic enzymes to peroxisomes and the extensive changes to glycolytic flux regulation that accompanied this re-localization. Evidence indicating loss of localized ATP provision via glycolytic enzymes therefore provides a novel contribution to an emerging theme of hidden diversity with respect to compartmentalization of the ubiquitous glycolytic pathway in eukaryotes. A possibility that trypanosome GAPDH-like protein additionally represents a degenerate example of a moonlighting protein is also discussed.

  2. Tracking the Re-organization of Motor Functions After Disconnective Surgery: A Longitudinal fMRI and DTI Study

    Directory of Open Access Journals (Sweden)

    Cristina Rosazza

    2018-06-01

    Full Text Available Objective: Mechanisms of motor plasticity are critical to maintain motor functions after cerebral damage. This study explores the mechanisms of motor reorganization occurring before and after surgery in four patients with drug-refractory epilepsy candidate to disconnective surgery.Methods: We studied four patients with early damage, who underwent tailored hemispheric surgery in adulthood, removing the cortical motor areas and disconnecting the corticospinal tract (CST from the affected hemisphere. Motor functions were assessed clinically, with functional MRI (fMRI tasks of arm and leg movement and Diffusion Tensor Imaging (DTI before and after surgery with assessments of up to 3 years. Quantifications of fMRI motor activations and DTI fractional anisotropy (FA color maps were performed to assess the lateralization of motor network. We hypothesized that lateralization of motor circuits assessed preoperatively with fMRI and DTI was useful to evaluate the motor outcome in these patients.Results: In two cases preoperative DTI-tractography did not reconstruct the CST, and FA-maps were strongly asymmetric. In the other two cases, the affected CST appeared reduced compared to the contralateral one, with modest asymmetry in the FA-maps. fMRI showed different degrees of lateralization of the motor network and the SMA of the intact hemisphere was mostly engaged in all cases. After surgery, patients with a strongly lateralized motor network showed a stable performance. By contrast, a patient with a more bilateral pattern showed worsening of the upper limb function. For all cases, fMRI activations shifted to the intact hemisphere. Structural alterations of motor circuits, observed with FA values, continued beyond 1 year after surgery.Conclusion: In our case series fMRI and DTI could track the longitudinal reorganization of motor functions. In these four patients the more the paretic limbs recruited the intact hemisphere in primary motor and associative

  3. Tracking the Re-organization of Motor Functions After Disconnective Surgery: A Longitudinal fMRI and DTI Study.

    Science.gov (United States)

    Rosazza, Cristina; Deleo, Francesco; D'Incerti, Ludovico; Antelmi, Luigi; Tringali, Giovanni; Didato, Giuseppe; Bruzzone, Maria G; Villani, Flavio; Ghielmetti, Francesco

    2018-01-01

    Objective: Mechanisms of motor plasticity are critical to maintain motor functions after cerebral damage. This study explores the mechanisms of motor reorganization occurring before and after surgery in four patients with drug-refractory epilepsy candidate to disconnective surgery. Methods: We studied four patients with early damage, who underwent tailored hemispheric surgery in adulthood, removing the cortical motor areas and disconnecting the corticospinal tract (CST) from the affected hemisphere. Motor functions were assessed clinically, with functional MRI (fMRI) tasks of arm and leg movement and Diffusion Tensor Imaging (DTI) before and after surgery with assessments of up to 3 years. Quantifications of fMRI motor activations and DTI fractional anisotropy (FA) color maps were performed to assess the lateralization of motor network. We hypothesized that lateralization of motor circuits assessed preoperatively with fMRI and DTI was useful to evaluate the motor outcome in these patients. Results: In two cases preoperative DTI-tractography did not reconstruct the CST, and FA-maps were strongly asymmetric. In the other two cases, the affected CST appeared reduced compared to the contralateral one, with modest asymmetry in the FA-maps. fMRI showed different degrees of lateralization of the motor network and the SMA of the intact hemisphere was mostly engaged in all cases. After surgery, patients with a strongly lateralized motor network showed a stable performance. By contrast, a patient with a more bilateral pattern showed worsening of the upper limb function. For all cases, fMRI activations shifted to the intact hemisphere. Structural alterations of motor circuits, observed with FA values, continued beyond 1 year after surgery. Conclusion: In our case series fMRI and DTI could track the longitudinal reorganization of motor functions. In these four patients the more the paretic limbs recruited the intact hemisphere in primary motor and associative areas, the

  4. Auditory-motor interactions in pediatric motor speech disorders: neurocomputational modeling of disordered development.

    Science.gov (United States)

    Terband, H; Maassen, B; Guenther, F H; Brumberg, J

    2014-01-01

    Differentiating the symptom complex due to phonological-level disorders, speech delay and pediatric motor speech disorders is a controversial issue in the field of pediatric speech and language pathology. The present study investigated the developmental interaction between neurological deficits in auditory and motor processes using computational modeling with the DIVA model. In a series of computer simulations, we investigated the effect of a motor processing deficit alone (MPD), and the effect of a motor processing deficit in combination with an auditory processing deficit (MPD+APD) on the trajectory and endpoint of speech motor development in the DIVA model. Simulation results showed that a motor programming deficit predominantly leads to deterioration on the phonological level (phonemic mappings) when auditory self-monitoring is intact, and on the systemic level (systemic mapping) if auditory self-monitoring is impaired. These findings suggest a close relation between quality of auditory self-monitoring and the involvement of phonological vs. motor processes in children with pediatric motor speech disorders. It is suggested that MPD+APD might be involved in typically apraxic speech output disorders and MPD in pediatric motor speech disorders that also have a phonological component. Possibilities to verify these hypotheses using empirical data collected from human subjects are discussed. The reader will be able to: (1) identify the difficulties in studying disordered speech motor development; (2) describe the differences in speech motor characteristics between SSD and subtype CAS; (3) describe the different types of learning that occur in the sensory-motor system during babbling and early speech acquisition; (4) identify the neural control subsystems involved in speech production; (5) describe the potential role of auditory self-monitoring in developmental speech disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Intact Acquisition and Short-Term Retention of Non-Motor Procedural Learning in Parkinson's Disease.

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    Muriel T N Panouillères

    Full Text Available Procedural learning is a form of memory where people implicitly acquire a skill through repeated practice. People with Parkinson's disease (PD have been found to acquire motor adaptation, a form of motor procedural learning, similarly to healthy older adults but they have deficits in long-term retention. A similar pattern of normal learning on initial exposure with a deficit in retention seen on subsequent days has also been seen in mirror-reading, a form of non-motor procedural learning. It is a well-studied fact that disrupting sleep will impair the consolidation of procedural memories. Given the prevalence of sleep disturbances in PD, the lack of retention on following days seen in these studies could simply be a side effect of this well-known symptom of PD. Because of this, we wondered whether people with PD would present with deficits in the short-term retention of a non-motor procedural learning task, when the test of retention was done the same day as the initial exposure. The aim of the present study was then to investigate acquisition and retention in the immediate short term of cognitive procedural learning using the mirror-reading task in people with PD. This task involved two conditions: one where triads of mirror-inverted words were always new that allowed assessing the learning of mirror-reading skill and another one where some of the triads were presented repeatedly during the experiment that allowed assessing the word-specific learning. People with PD both ON and OFF their normal medication were compared to healthy older adults and young adults. Participants were re-tested 50 minutes break after initial exposure to probe for short-term retention. The results of this study show that all groups of participants acquired and retained the two skills (mirror-reading and word-specific similarly. These results suggest that neither healthy ageing nor the degeneration within the basal ganglia that occurs in PD does affect the mechanisms

  6. An intact action-perception coupling depends on the integrity of the cerebellum.

    Science.gov (United States)

    Christensen, Andrea; Giese, Martin A; Sultan, Fahad; Mueller, Oliver M; Goericke, Sophia L; Ilg, Winfried; Timmann, Dagmar

    2014-05-07

    It is widely accepted that action and perception in humans functionally interact on multiple levels. Moreover, areas originally suggested to be predominantly motor-related, as the cerebellum, are also involved in action observation. However, as yet, few studies provided unequivocal evidence that the cerebellum is involved in the action perception coupling (APC), specifically in the integration of motor and multisensory information for perception. We addressed this question studying patients with focal cerebellar lesions in a virtual-reality paradigm measuring the effect of action execution on action perception presenting self-generated movements as point lights. We measured the visual sensitivity to the point light stimuli based on signal detection theory. Compared with healthy controls cerebellar patients showed no beneficial influence of action execution on perception indicating deficits in APC. Applying lesion symptom mapping, we identified distinct areas in the dentate nucleus and the lateral cerebellum of both hemispheres that are causally involved in APC. Lesions of the right ventral dentate, the ipsilateral motor representations (lobules V/VI), and most interestingly the contralateral posterior cerebellum (lobule VII) impede the benefits of motor execution on perception. We conclude that the cerebellum establishes time-dependent multisensory representations on different levels, relevant for motor control as well as supporting action perception. Ipsilateral cerebellar motor representations are thought to support the somatosensory state estimate of ongoing movements, whereas the ventral dentate and the contralateral posterior cerebellum likely support sensorimotor integration in the cerebellar-parietal loops. Both the correct somatosensory as well as the multisensory state representations are vital for an intact APC.

  7. Characterization of a subunit of the outer dynein arm docking complex necessary for correct flagellar assembly in Leishmania donovani.

    Directory of Open Access Journals (Sweden)

    Simone Harder

    Full Text Available BACKGROUND: In order to proceed through their life cycle, Leishmania parasites switch between sandflies and mammals. The flagellated promastigote cells transmitted by the insect vector are phagocytized by macrophages within the mammalian host and convert into the amastigote stage, which possesses a rudimentary flagellum only. During an earlier proteomic study of the stage differentiation of the parasite we identified a component of the outer dynein arm docking complex, a structure of the flagellar axoneme. The 70 kDa subunit of the outer dynein arm docking complex consists of three subunits altogether and is essential for the assembly of the outer dynein arm onto the doublet microtubule of the flagella. According to the nomenclature of the well-studied Chlamydomonas reinhardtii complex we named the Leishmania protein LdDC2. METHODOLOGY/PRINCIPAL FINDINGS: This study features a characterization of the protein over the life cycle of the parasite. It is synthesized exclusively in the promastigote stage and localizes to the flagellum. Gene replacement mutants of lddc2 show reduced growth rates and diminished flagellar length. Additionally, the normally spindle-shaped promastigote parasites reveal a more spherical cell shape giving them an amastigote-like appearance. The mutants lose their motility and wiggle in place. Ultrastructural analyses reveal that the outer dynein arm is missing. Furthermore, expression of the amastigote-specific A2 gene family was detected in the deletion mutants in the absence of a stage conversion stimulus. In vitro infectivity is slightly increased in the mutant cell line compared to wild-type Leishmania donovani parasites. CONCLUSIONS/SIGNIFICANCE: Our results indicate that the correct assembly of the flagellum has a great influence on the investigated characteristics of Leishmania parasites. The lack of a single flagellar protein causes an aberrant morphology, impaired growth and altered infectiousness of the parasite.

  8. Comparison of Intact PTH and Bio-Intact PTH Assays Among Non-Dialysis Dependent Chronic Kidney Disease Patients.

    Science.gov (United States)

    Einbinder, Yael; Benchetrit, Sydney; Golan, Eliezer; Zitman-Gal, Tali

    2017-09-01

    The third-generation bio-intact parathyroid hormone (PTH) (1-84) assay was designed to overcome problems associated with the detection of C-terminal fragments by the second-generation intact PTH assay. The two assays have been compared primarily among dialysis populations. The present study evaluated the correlations and differences between these two PTH assays among patients with chronic kidney disease (CKD) stages 3 to 5 not yet on dialysis. Blood samples were collected from 98 patients with CKD stages 3 to 5. PTH concentrations were measured simultaneously by using the second-generation - PTH intact-STAT and third-generation bio-intact 1-84 PTH assays. Other serum biomarkers of bone mineral disorders were also assessed. CKD stage was calculated by using the CKD-Epidemiology Collaboration (EPI) formula. Serum bio-intact PTH concentrations were strongly correlated but significantly lower than the intact PTH concentrations (r=0.963, Pbio-intact PTH) positively correlated with urea (r=0.523, r=0.504; P=0.002, respectively), phosphorus (r=0.532, r=0.521; Pbio-intact PTH assay detected significantly lower PTH concentrations compared with intact PTH assay. Additional studies that correlate the diagnosis and management of CKD mineral and bone disorders with bone histomorphometric findings are needed to determine whether bio-intact PTH assay results are better surrogate markers in these early stages of CKD. © The Korean Society for Laboratory Medicine

  9. Peripheral Nerve Injury in Developing Rats Reorganizes Representation Pattern in Motor Cortex

    Science.gov (United States)

    Donoghue, John P.; Sanes, Jerome N.

    1987-02-01

    We investigated the effect of neonatal nerve lesions on cerebral motor cortex organization by comparing the cortical motor representation of normal adult rats with adult rats that had one forelimb removed on the day of birth. Mapping of cerebral neocortex with electrical stimulation revealed an altered relationship between the motor cortex and the remaining muscles. Whereas distal forelimb movements are normally elicited at the lowest threshold in the motor cortex forelimb area, the same stimuli activated shoulder and trunk muscles in experimental animals. In addition, an expanded cortical representation of intact body parts was present and there was an absence of a distinct portion of motor cortex. These data demonstrate that representation patterns in motor cortex can be altered by peripheral nerve injury during development.

  10. Complex Interplay between FleQ, Cyclic Diguanylate and Multiple σ Factors Coordinately Regulates Flagellar Motility and Biofilm Development in Pseudomonas putida.

    Directory of Open Access Journals (Sweden)

    Alicia Jiménez-Fernández

    Full Text Available Most bacteria alternate between a free living planktonic lifestyle and the formation of structured surface-associated communities named biofilms. The transition between these two lifestyles requires a precise and timely regulation of the factors involved in each of the stages that has been likened to a developmental process. Here we characterize the involvement of the transcriptional regulator FleQ and the second messenger cyclic diguanylate in the coordinate regulation of multiple functions related to motility and surface colonization in Pseudomonas putida. Disruption of fleQ caused strong defects in flagellar motility, biofilm formation and surface attachment, and the ability of this mutation to suppress multiple biofilm-related phenotypes associated to cyclic diguanylate overproduction suggests that FleQ mediates cyclic diguanylate signaling critical to biofilm growth. We have constructed a library containing 94 promoters potentially involved in motility and biofilm development fused to gfp and lacZ, screened this library for FleQ and cyclic diguanylate regulation, and assessed the involvement of alternative σ factors σN and FliA in the transcription of FleQ-regulated promoters. Our results suggest a dual mode of action for FleQ. Low cyclic diguanylate levels favor FleQ interaction with σN-dependent promoters to activate the flagellar cascade, encompassing the flagellar cluster and additional genes involved in cyclic diguanylate metabolism, signal transduction and gene regulation. On the other hand, characterization of the FleQ-regulated σN- and FliA-independent PlapA and PbcsD promoters revealed two disparate regulatory mechanisms leading to a similar outcome: the synthesis of biofilm matrix components in response to increased cyclic diguanylate levels.

  11. The flagellar master operon flhDC is a pleiotropic regulator involved in motility and virulence of the fish pathogen Yersinia ruckeri

    Science.gov (United States)

    Aims: To investigate the function of the master flagellar operon flhDC in the fish pathogen Yersinia ruckeri and compare the effect of flhD mutation to a naturally occurring mutation causing loss-of-motility in emergent biotype 2 (BT2) strains. Methods and Results: In this study isogenic Y. ruckeri ...

  12. Once more on the equilibrium-point hypothesis (lambda model) for motor control.

    Science.gov (United States)

    Feldman, A G

    1986-03-01

    The equilibrium control hypothesis (lambda model) is considered with special reference to the following concepts: (a) the length-force invariant characteristic (IC) of the muscle together with central and reflex systems subserving its activity; (b) the tonic stretch reflex threshold (lambda) as an independent measure of central commands descending to alpha and gamma motoneurons; (c) the equilibrium point, defined in terms of lambda, IC and static load characteristics, which is associated with the notion that posture and movement are controlled by a single mechanism; and (d) the muscle activation area (a reformulation of the "size principle")--the area of kinematic and command variables in which a rank-ordered recruitment of motor units takes place. The model is used for the interpretation of various motor phenomena, particularly electromyographic patterns. The stretch reflex in the lambda model has no mechanism to follow-up a certain muscle length prescribed by central commands. Rather, its task is to bring the system to an equilibrium, load-dependent position. Another currently popular version defines the equilibrium point concept in terms of alpha motoneuron activity alone (the alpha model). Although the model imitates (as does the lambda model) spring-like properties of motor performance, it nevertheless is inconsistent with a substantial data base on intact motor control. An analysis of alpha models, including their treatment of motor performance in deafferented animals, reveals that they suffer from grave shortcomings. It is concluded that parameterization of the stretch reflex is a basis for intact motor control. Muscle deafferentation impairs this graceful mechanism though it does not remove the possibility of movement.

  13. CCDC151 Mutations Cause Primary Ciliary Dyskinesia by Disruption of the Outer Dynein Arm Docking Complex Formation

    NARCIS (Netherlands)

    Hjeij, R.; Onoufriadis, A.; Watson, C.M.; Slagle, C.E.; Klena, N.T.; Dougherty, G.W.; Kurkowiak, M.; Loges, N.T.; Diggle, C.P.; Morante, N.F.; Gabriel, G.C.; Lemke, K.L.; Li, Y.; Pennekamp, P.; Menchen, T.; Konert, F.; Marthin, J.K.; Mans, D.A.; Letteboer, S.J.F.; Werner, C.; Burgoyne, T.; Westermann, C.; Rutman, A.; Carr, I.M.; O'Callaghan, C.; Moya, E.; Chung, E.M.; Consortium, U.K.; Sheridan, E.; Nielsen, K.G.; Roepman, R.; Bartscherer, K.; Burdine, R.D.; Lo, C.W.; Omran, H.; Mitchison, H.M.

    2014-01-01

    A diverse family of cytoskeletal dynein motors powers various cellular transport systems, including axonemal dyneins generating the force for ciliary and flagellar beating essential to movement of extracellular fluids and of cells through fluid. Multisubunit outer dynein arm (ODA) motor complexes,

  14. Impairment of Procedural Learning and Motor Intracortical Inhibition in Neurofibromatosis Type 1 Patients

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    Máximo Zimerman

    2015-10-01

    Interpretations: Collectively, the present results provide evidence that learning of a motor skill is impaired even in clinically intact NF1 patients based, at least partially, on a GABAergic-cortical dysfunctioning as suggested in previous animal work.

  15. Positive Youth Development, Life Satisfaction and Problem Behaviors of Adolescents in Intact and Non-Intact Families in Hong Kong

    Directory of Open Access Journals (Sweden)

    Daniel Tan Lei Shek

    2013-08-01

    Full Text Available This study investigated whether Chinese adolescents living in intact and non-intact families differed in their positive development, life satisfaction, and risk behavior. A total of 3,328 Secondary 1 students responded to measures of positive youth development (such as resilience and psychosocial competencies, life satisfaction, and risk behavior (substance abuse, delinquency, Internet addiction, consumption of pornographic materials, self-harm, and behavioral intention to engage in problem behavior. Findings revealed that adolescents growing up in intact families reported higher levels of positive developmental outcomes and life satisfaction as compared with adolescents from non-intact families. Adolescents in non-intact families also reported higher levels of risk behaviors than those growing up in intact families.

  16. Cloning, purification, crystallization and preliminary X-ray studies of flagellar hook scaffolding protein FlgD from Pseudomonas aeruginosa PAO1

    International Nuclear Information System (INIS)

    Luo, Miao; Niu, Siqiang; Yin, Yibing; Huang, Ailong; Wang, Deqiang

    2009-01-01

    In order to better elucidate the functions of FlgD in flagellar hook biosynthesis, the three-dimensional structure of FlgD is being determined by X-ray crystallography. Here, the expression, purification, crystallization and preliminary crystallographic analysis of FlgD from P. aeruginosa are reported. FlgD regulates the assembly of the hook cap structure to prevent leakage of hook monomers into the medium and hook monomer polymerization and also plays a role in determination of the correct hook length, with the help of the FliK protein. In order to better elucidate the functions of FlgD in flagellar hook biosynthesis, the three-dimensional structure of FlgD is being determined by X-ray crystallography. Here, the expression, purification, crystallization and preliminary crystallographic analysis of FlgD from P. aeruginosa are reported. The crystal belonged to space group I222 and diffracted to a resolution of 2.5 Å, with unit-cell parameters a = 116.47, b = 118.71, c = 118.85 Å. The crystals are most likely to contain three molecules in the asymmetric unit, with a V M value of 2.73 Å 3 Da −1

  17. Exploratory investigations of hypervelocity intact capture spectroscopy

    Science.gov (United States)

    Tsou, P.; Griffiths, D. J.

    1993-01-01

    The ability to capture hypervelocity projectiles intact opens a new technique available for hypervelocity research. A determination of the reactions taking place between the projectile and the capture medium during the process of intact capture is extremely important to an understanding of the intact capture phenomenon, to improving the capture technique, and to developing a theory describing the phenomenon. The intact capture of hypervelocity projectiles by underdense media generates spectra, characteristic of the material species of projectile and capture medium involved. Initial exploratory results into real-time characterization of hypervelocity intact capture techniques by spectroscopy include ultra-violet and visible spectra obtained by use of reflecting gratings, transmitting gratings, and prisms, and recorded by photographic and electronic means. Spectrometry proved to be a valuable real-time diagnostic tool for hypervelocity intact capture events, offering understanding of the interactions of the projectile and the capture medium during the initial period and providing information not obtainable by other characterizations. Preliminary results and analyses of spectra produced by the intact capture of hypervelocity aluminum spheres in polyethylene (PE), polystyrene (PS), and polyurethane (PU) foams are presented. Included are tentative emission species identifications, as well as gray body temperatures produced in the intact capture process.

  18. Intact glycopeptide characterization using mass spectrometry.

    Science.gov (United States)

    Cao, Li; Qu, Yi; Zhang, Zhaorui; Wang, Zhe; Prytkova, Iya; Wu, Si

    2016-05-01

    Glycosylation is one of the most prominent and extensively studied protein post-translational modifications. However, traditional proteomic studies at the peptide level (bottom-up) rarely characterize intact glycopeptides (glycosylated peptides without removing glycans), so no glycoprotein heterogeneity information is retained. Intact glycopeptide characterization, on the other hand, provides opportunities to simultaneously elucidate the glycan structure and the glycosylation site needed to reveal the actual biological function of protein glycosylation. Recently, significant improvements have been made in the characterization of intact glycopeptides, ranging from enrichment and separation, mass spectroscopy (MS) detection, to bioinformatics analysis. In this review, we recapitulated currently available intact glycopeptide characterization methods with respect to their advantages and limitations as well as their potential applications.

  19. Basic timing abilities stay intact in patients with musician's dystonia.

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    M C van der Steen

    Full Text Available Task-specific focal dystonia is a movement disorder that is characterized by the loss of voluntary motor control in extensively trained movements. Musician's dystonia is a type of task-specific dystonia that is elicited in professional musicians during instrumental playing. The disorder has been associated with deficits in timing. In order to test the hypothesis that basic timing abilities are affected by musician's dystonia, we investigated a group of patients (N = 15 and a matched control group (N = 15 on a battery of sensory and sensorimotor synchronization tasks. Results did not show any deficits in auditory-motor processing for patients relative to controls. Both groups benefited from a pacing sequence that adapted to their timing (in a sensorimotor synchronization task at a stable tempo. In a purely perceptual task, both groups were able to detect a misaligned metronome when it was late rather than early relative to a musical beat. Overall, the results suggest that basic timing abilities stay intact in patients with musician's dystonia. This supports the idea that musician's dystonia is a highly task-specific movement disorder in which patients are mostly impaired in tasks closely related to the demands of actually playing their instrument.

  20. Basic Timing Abilities Stay Intact in Patients with Musician's Dystonia

    Science.gov (United States)

    van der Steen, M. C.; van Vugt, Floris T.; Keller, Peter E.; Altenmüller, Eckart

    2014-01-01

    Task-specific focal dystonia is a movement disorder that is characterized by the loss of voluntary motor control in extensively trained movements. Musician's dystonia is a type of task-specific dystonia that is elicited in professional musicians during instrumental playing. The disorder has been associated with deficits in timing. In order to test the hypothesis that basic timing abilities are affected by musician's dystonia, we investigated a group of patients (N = 15) and a matched control group (N = 15) on a battery of sensory and sensorimotor synchronization tasks. Results did not show any deficits in auditory-motor processing for patients relative to controls. Both groups benefited from a pacing sequence that adapted to their timing (in a sensorimotor synchronization task at a stable tempo). In a purely perceptual task, both groups were able to detect a misaligned metronome when it was late rather than early relative to a musical beat. Overall, the results suggest that basic timing abilities stay intact in patients with musician's dystonia. This supports the idea that musician's dystonia is a highly task-specific movement disorder in which patients are mostly impaired in tasks closely related to the demands of actually playing their instrument. PMID:24667273

  1. Damage to the medial motor system in stroke patients with motor neglect

    Directory of Open Access Journals (Sweden)

    Raffaella eMigliaccio

    2014-06-01

    Full Text Available Background and objectives. Motor neglect (MN is a clinically important condition whereby patients with unilateral brain lesions fail to move their contralateral limbs, despite normal muscle strength, reflexes, and sensation. MN has been associated with various lesion sites, including the parietal and frontal cortex, the internal capsule, the lenticulostriate nuclei, and the thalamus. In the present study, we explored the hypothesis that MN depends on a dysfunction of the medial motor system by performing a detailed anatomical analysis in four patients with MN.Methods. Ten patients participated in the study: four with MN, four with left visual neglect but without MN, and three patients with left hemiplegia without MN. We used specific scales for clinical and neuropsychological assessment. We drew the lesion borders directly onto the original brain images of each patient, and plotted the lesions on anatomical atlases for grey and white matter. Results. Lesion locations were highly heterogeneous in our MN patients, and included frontal and parietal sites, basal ganglia and white matter. The only consistently damaged structure across all MN patients was the cingulum bundle, a major pathway of the medial motor system important for motor initiative, and a key connection with limbic structures crucial for motivational aspects of actions. Three MN patients with additional damage to lateral fronto-parietal networks had also signs of contralesional visual neglect. The cingulum bundle was intact in all the control patients with visual neglect or hemiplegia.Conclusions. Cingulum damage may induce MN through unilateral dysfunction of the medial motor system. Additional lateral fronto-parietal dysfunction can result in the association with visual neglect.

  2. Motor Decline in Clinically Presymptomatic Spinocerebellar Ataxia Type 2 Gene Carriers

    Science.gov (United States)

    Velázquez-Perez, Luis; Díaz, Rosalinda; Pérez-González, Ruth; Canales, Nalia; Rodríguez-Labrada, Roberto; Medrano, Jacquelín; Sánchez, Gilberto; Almaguer-Mederos, Luis; Torres, Cira; Fernandez-Ruiz, Juan

    2009-01-01

    Background Motor deficits are a critical component of the clinical characteristics of patients with spinocerebellar ataxia type 2. However, there is no current information on the preclinical manifestation of those motor deficits in presymptomatic gene carriers. To further understand and characterize the onset of the clinical manifestation in this disease, we tested presymptomatic spinocerebellar ataxia type 2 gene carriers, and volunteers, in a task that evaluates their motor performance and their motor learning capabilities. Methods and Findings 28 presymptomatic spinocerebellar ataxia type 2 gene carriers and an equal number of control volunteers matched for age and gender participated in the study. Both groups were tested in a prism adaptation task known to be sensible to both motor performance and visuomotor learning deficits. Our results clearly show that although motor learning capabilities are intact, motor performance deficits are present even years before the clinical manifestation of the disease start. Conclusions The results show a clear deficit in motor performance that can be detected years before the clinical onset of the disease. This motor performance deficit appears before any motor learning or clinical manifestations of the disease. These observations identify the performance coefficient as an objective and quantitative physiological biomarker that could be useful to assess the efficiency of different therapeutic agents. PMID:19401771

  3. Serum steroid levels in intact and endocrine ablated BALB/c nude mice and their intact littermates

    DEFF Research Database (Denmark)

    Brünner, N; Svenstrup, B; Spang-Thomsen, M

    1986-01-01

    An investigation was made of the serum steroid levels found in intact and endocrine ablated nude mice of both sexes and in their intact homozygous littermates. The results showed that nude mice have a normal steroidogenesis, but with decreased levels of circulating steroids compared to those...

  4. Inhibition of the primary motor cortex and the upgoing thumb sign

    Directory of Open Access Journals (Sweden)

    Antonia Nucera

    2017-09-01

    Full Text Available Background: The upgoing thumb sign has been frequently observed in patients with minor strokes and transient ischemic attacks as an indicator of brain involvement. We assessed the effect of primary motor cortex (M1 inhibition in the development of the upgoing thumb sign. Methods: Used repetitive Transcranial Magnetic Stimulation (rTMS, 1Hz frequency for 15min, 1s ISI, 900 pulses at 60% of resting motor threshold to inhibit the right or left primary motor cortex of 10 healthy individuals. Participants were examined before and after rTMS by a neurologist who was blind to the site of motor cortex inhibition. Results: 10 neurological intact participants (5 women/5 men were recruited for this study. 2 cases were excluded due to pre-existing possible thumb signs. After the inhibition of the primary motor cortex, in 6 subjects out of 8, we observed a thumb sign contralateral to the site of primary motor cortex inhibition. In one subject an ipsilateral thumbs sign was noted. In another case, we did not find an upgoing thumb sign. Conclusion: The upgoing thumb sign is a subtle neurological finding that may be related to the primary motor cortex or corticospinal pathways involvements. Keywords: Corticospinal tract, Upper motor neuron lesions, Primary motor cortex, Transcranial magnetic stimulation

  5. Comparison of independent screens on differentially vulnerable motor neurons reveals alpha-synuclein as a common modifier in motor neuron diseases.

    Science.gov (United States)

    Kline, Rachel A; Kaifer, Kevin A; Osman, Erkan Y; Carella, Francesco; Tiberi, Ariana; Ross, Jolill; Pennetta, Giuseppa; Lorson, Christian L; Murray, Lyndsay M

    2017-03-01

    The term "motor neuron disease" encompasses a spectrum of disorders in which motor neurons are the primary pathological target. However, in both patients and animal models of these diseases, not all motor neurons are equally vulnerable, in that while some motor neurons are lost very early in disease, others remain comparatively intact, even at late stages. This creates a valuable system to investigate the factors that regulate motor neuron vulnerability. In this study, we aim to use this experimental paradigm to identify potential transcriptional modifiers. We have compared the transcriptome of motor neurons from healthy wild-type mice, which are differentially vulnerable in the childhood motor neuron disease Spinal Muscular Atrophy (SMA), and have identified 910 transcriptional changes. We have compared this data set with published microarray data sets on other differentially vulnerable motor neurons. These neurons were differentially vulnerable in the adult onset motor neuron disease Amyotrophic Lateral Sclerosis (ALS), but the screen was performed on the equivalent population of neurons from neurologically normal human, rat and mouse. This cross species comparison has generated a refined list of differentially expressed genes, including CELF5, Col5a2, PGEMN1, SNCA, Stmn1 and HOXa5, alongside a further enrichment for synaptic and axonal transcripts. As an in vivo validation, we demonstrate that the manipulation of a significant number of these transcripts can modify the neurodegenerative phenotype observed in a Drosophila line carrying an ALS causing mutation. Finally, we demonstrate that vector-mediated expression of alpha-synuclein (SNCA), a transcript decreased in selectively vulnerable motor neurons in all four screens, can extend life span, increase weight and decrease neuromuscular junction pathology in a mouse model of SMA. In summary, we have combined multiple data sets to identify transcripts, which are strong candidates for being phenotypic modifiers

  6. Sleep benefits consolidation of visuo-motor adaptation learning in older adults.

    Science.gov (United States)

    Mantua, Janna; Baran, Bengi; Spencer, Rebecca M C

    2016-02-01

    Sleep is beneficial for performance across a range of memory tasks in young adults, but whether memories are similarly consolidated in older adults is less clear. Performance benefits have been observed following sleep in older adults for declarative learning tasks, but this benefit may be reduced for non-declarative, motor skill learning tasks. To date, studies of sleep-dependent consolidation of motor learning in older adults are limited to motor sequence tasks. To examine whether reduced sleep-dependent consolidation in older adults is generalizable to other forms of motor skill learning, we examined performance changes over intervals of sleep and wake in young (n = 62) and older adults (n = 61) using a mirror-tracing task, which assesses visuo-motor adaptation learning. Participants learned the task either in the morning or in evening, and performance was assessed following a 12-h interval containing overnight sleep or daytime wake. Contrary to our prediction, both young adults and older adults exhibited sleep-dependent gains in visuo-motor adaptation. There was a correlation between performance improvement over sleep and percent of the night in non-REM stage 2 sleep. These results indicate that motor skill consolidation remains intact with increasing age although this relationship may be limited to specific forms of motor skill learning.

  7. Beta-band intermuscular coherence: a novel biomarker of upper motor neuron dysfunction in motor neuron disease

    Science.gov (United States)

    Fisher, Karen M.; Zaaimi, Boubker; Williams, Timothy L.; Baker, Stuart N.

    2012-01-01

    In motor neuron disease, the focus of therapy is to prevent or slow neuronal degeneration with neuroprotective pharmacological agents; early diagnosis and treatment are thus essential. Incorporation of needle electromyographic evidence of lower motor neuron degeneration into diagnostic criteria has undoubtedly advanced diagnosis, but even earlier diagnosis might be possible by including tests of subclinical upper motor neuron disease. We hypothesized that beta-band (15–30 Hz) intermuscular coherence could be used as an electrophysiological marker of upper motor neuron integrity in such patients. We measured intermuscular coherence in eight patients who conformed to established diagnostic criteria for primary lateral sclerosis and six patients with progressive muscular atrophy, together with 16 age-matched controls. In the primary lateral sclerosis variant of motor neuron disease, there is selective destruction of motor cortical layer V pyramidal neurons and degeneration of the corticospinal tract, without involvement of anterior horn cells. In progressive muscular atrophy, there is selective degeneration of anterior horn cells but a normal corticospinal tract. All patients with primary lateral sclerosis had abnormal motor-evoked potentials as assessed using transcranial magnetic stimulation, whereas these were similar to controls in progressive muscular atrophy. Upper and lower limb intermuscular coherence was measured during a precision grip and an ankle dorsiflexion task, respectively. Significant beta-band coherence was observed in all control subjects and all patients with progressive muscular atrophy tested, but not in the patients with primary lateral sclerosis. We conclude that intermuscular coherence in the 15–30 Hz range is dependent on an intact corticospinal tract but persists in the face of selective anterior horn cell destruction. Based on the distributions of coherence values measured from patients with primary lateral sclerosis and control

  8. Analysis of both perceptual and motor skills of children with dyslalia before their entering of the first grade of primary school

    OpenAIRE

    Pešlová, Markéta

    2015-01-01

    The thesis deals with an analysis of both perceptual and motor skills of children with dyslalia before their entering of the first grade of primary school. The aim of this thesis is to determine the level of perceptual and motor skills of both preschool children with dyslalia and intact children. The preschool age of a child is described in the theoretical part of the thesis. The thesis also defines dyslalia. Further chapters deal with auditory and visual perception. The area of motor skills ...

  9. Intact glycopeptide characterization using mass spectrometry

    OpenAIRE

    Cao, Li; Qu, Yi; Zhang, Zhaorui; Wang, Zhe; Prykova, Iya; Wu, Si

    2016-01-01

    Glycosylation is one of the most prominent and extensively studied protein post-translational modifications. However, traditional proteomic studies at the peptide level (bottom-up) rarely characterize intact glycopeptides (glycosylated peptides without removing glycans), so no glycoprotein heterogeneity information is retained. Intact glycopeptide characterization, on the other hand, provides opportunities to simultaneously elucidate the glycan structure and the glycosylation site needed to r...

  10. Coordination of fictive motor activity in the larval zebrafish is generated by non-segmental mechanisms.

    Directory of Open Access Journals (Sweden)

    Timothy D Wiggin

    Full Text Available The cellular and network basis for most vertebrate locomotor central pattern generators (CPGs is incompletely characterized, but organizational models based on known CPG architectures have been proposed. Segmental models propose that each spinal segment contains a circuit that controls local coordination and sends longer projections to coordinate activity between segments. Unsegmented/continuous models propose that patterned motor output is driven by gradients of neurons and synapses that do not have segmental boundaries. We tested these ideas in the larval zebrafish, an animal that swims in discrete episodes, each of which is composed of coordinated motor bursts that progress rostrocaudally and alternate from side to side. We perturbed the spinal cord using spinal transections or strychnine application and measured the effect on fictive motor output. Spinal transections eliminated episode structure, and reduced both rostrocaudal and side-to-side coordination. Preparations with fewer intact segments were more severely affected, and preparations consisting of midbody and caudal segments were more severely affected than those consisting of rostral segments. In reduced preparations with the same number of intact spinal segments, side-to-side coordination was more severely disrupted than rostrocaudal coordination. Reducing glycine receptor signaling with strychnine reversibly disrupted both rostrocaudal and side-to-side coordination in spinalized larvae without disrupting episodic structure. Both spinal transection and strychnine decreased the stability of the motor rhythm, but this effect was not causal in reducing coordination. These results are inconsistent with a segmented model of the spinal cord and are better explained by a continuous model in which motor neuron coordination is controlled by segment-spanning microcircuits.

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

    Science.gov (United States)

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

    2017-10-18

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

  12. Dopamine D1 receptor activation maintains motor coordination in injured rats but does not accelerate the recovery of the motor coordination deficit.

    Science.gov (United States)

    Avila-Luna, Alberto; Gálvez-Rosas, Arturo; Alfaro-Rodríguez, Alfonso; Reyes-Legorreta, Celia; Garza-Montaño, Paloma; González-Piña, Rigoberto; Bueno-Nava, Antonio

    2018-01-15

    The sensorimotor cortex and the striatum are interconnected by the corticostriatal pathway, suggesting that cortical injury alters the striatal function that is associated with skilled movements and motor learning, which are functions that may be modulated by dopamine (DA). In this study, we explored motor coordination and balance in order to investigate whether the activation of D 1 receptors (D 1 Rs) modulates functional recovery after cortical injury. The results of the beam-walking test showed motor deficit in the injured group at 24, 48 and 96h post-injury, and the recovery time was observed at 192h after cortical injury. In the sham and injured rats, systemic administration of the D 1 R antagonist SCH-23390 (1mg/kg) alone at 24, 48, 96 and 192h significantly (Pmotor deficit, while administration of the D 1 R agonist SKF-38393 alone (2, 3 and 4mg/kg) at 24, 48, 96 and 192h post-injury did not produce a significant difference; however, the co-administration of SKF-38393 and SCH-23390 prevented the antagonist-induced increase in the motor deficit. The cortical+striatal injury showed significantly increased the motor deficit at 24, 48, 96 and 192h post-injury (Pmotor recovery, but the activation of D 1 Rs maintained motor coordination, confirming that an intact striatum may be necessary for achieving recovery. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Motor control and the management of musculoskeletal dysfunction.

    Science.gov (United States)

    van Vliet, Paulette M; Heneghan, Nicola R

    2006-08-01

    This paper aims to develop understanding of three important motor control issues--feedforward mechanisms, cortical plasticity and task-specificity and assess the implications for musculoskeletal practice. A model of control for the reach-to-grasp movement illustrates how the central nervous system integrates sensorimotor processes to control complex movements. Feedforward mechanisms, an essential element of motor control, are altered in neurologically intact patients with chronic neck pain and low back pain. In healthy subjects, cortical mapping studies using transcranial magnetic stimulation have demonstrated that neural pathways adapt according to what and how much is practised. Neuroplasticity has also been demonstrated in a number of musculoskeletal conditions, where cortical maps are altered compared to normal. Behavioural and neurophysiological studies indicate that environmental and task constraints such as the goal of the task and an object's shape and size, are determinants of the motor schema for reaching and other movements. Consideration of motor control issues as well as signs and symptoms, may facilitate management of musculoskeletal conditions and improve outcome. Practice of entire everyday tasks at an early stage and systematic variation of the task is recommended. Training should be directed with the aim of re-educating feedforward mechanisms where necessary and the amount of practice should be sufficient to cause changes in cortical activity.

  14. Minimum Requirements of Flagellation and Motility for Infection of Agrobacterium sp. Strain H13-3 by Flagellotropic Bacteriophage 7-7-1

    Science.gov (United States)

    Yen, Jiun Y.; Broadway, Katherine M.

    2012-01-01

    The flagellotropic phage 7-7-1 specifically adsorbs to Agrobacterium sp. strain H13-3 (formerly Rhizobium lupini H13-3) flagella for efficient host infection. The Agrobacterium sp. H13-3 flagellum is complex and consists of three flagellin proteins: the primary flagellin FlaA, which is essential for motility, and the secondary flagellins FlaB and FlaD, which have minor functions in motility. Using quantitative infectivity assays, we showed that absence of FlaD had no effect on phage infection, while absence of FlaB resulted in a 2.5-fold increase in infectivity. A flaA deletion strain, which produces straight and severely truncated flagella, experienced a significantly reduced infectivity, similar to that of a flaB flaD strain, which produces a low number of straight flagella. A strain lacking all three flagellin genes is phage resistant. In addition to flagellation, flagellar rotation is required for infection. A strain that is nonmotile due to an in-frame deletion in the gene encoding the motor component MotA is resistant to phage infection. We also generated two strains with point mutations in the motA gene resulting in replacement of the conserved charged residue Glu98, which is important for modulation of rotary speed. A change to the neutral Gln caused the flagellar motor to rotate at a constant high speed, allowing a 2.2-fold-enhanced infectivity. A change to the positively charged Lys caused a jiggly motility phenotype with very slow flagellar rotation, which significantly reduced the efficiency of infection. In conclusion, flagellar number and length, as well as speed of flagellar rotation, are important determinants for infection by phage 7-7-1. PMID:22865074

  15. [Trigeminal motor paralysis and dislocation of the temporo-mandibular joints].

    Science.gov (United States)

    Ohkawa, S; Yoshida, T; Ohsumi, Y; Tabuchi, M

    1996-07-01

    A 64-year-old woman with diabetes mellitus was admitted to our hospital with left hemiparesis of sudden onset. A brain MRI demonstrated a cerebral infarction in the ventral part of the right lower pons. When left hemiparesis worsened, she had dislocation of the temporo-mandibular joints repeatedly. Then, her lower jaw deviated to the right when she opened her mouth. Also, there was decreased contraction of the right masseter when she clenched her teeth. These findings suggest that there was trigeminal motor paralysis on the right side resulting from involvement of the intrapontine trigeminal motor nerve. She has no history of dislocation of the temporo-mandibular joints. An X-ray film showed that the temporo-mandibular joints were intact. Thus, it is possible that deviation of the lower jaw was the cause of this dislocation. We suspect that dislocation of the temporo-mandibular joints may occur as a complication of unilateral trigeminal motor paralysis. This has not been reported to our knowledge.

  16. Strategies for Analyzing Data from Intact Groups.

    Science.gov (United States)

    Cross, Lawrence H.; Lane, Carolyn E.

    Action research often necessitates the use of intact groups for the comparison of educational treatments or programs. This paper considers several analytical methods that might be used for such situations when pretest scores indicate that these intact groups differ significantly initially. The methods considered include gain score analysis of…

  17. Small Particles Intact Capture Experiment (SPICE)

    Science.gov (United States)

    Nishioka, Ken-Ji; Carle, G. C.; Bunch, T. E.; Mendez, David J.; Ryder, J. T.

    1994-01-01

    The Small Particles Intact Capture Experiment (SPICE) will develop technologies and engineering techniques necessary to capture nearly intact, uncontaminated cosmic and interplanetary dust particles (IDP's). Successful capture of such particles will benefit the exobiology and planetary science communities by providing particulate samples that may have survived unaltered since the formation of the solar system. Characterization of these particles may contribute fundamental data to our knowledge of how these particles could have formed into our planet Earth and, perhaps, contributed to the beginnings of life. The term 'uncontaminated' means that captured cosmic and IDP particles are free of organic contamination from the capture process and the term 'nearly intact capture' means that their chemical and elemental components are not materially altered during capture. The key to capturing cosmic and IDP particles that are organic-contamination free and nearly intact is the capture medium. Initial screening of capture media included organic foams, multiple thin foil layers, and aerogel (a silica gel); but, with the exception of aerogel, the requirements of no contamination or nearly intact capture were not met. To ensure no contamination of particles in the capture process, high-purity aerogel was chosen. High-purity aerogel results in high clarity (visual clearness), a useful quality in detection and recovery of embedded captured particles from the aerogel. P. Tsou at the Jet Propulsion Laboratory (JPL) originally described the use of aerogel for this purpose and reported laboratory test results. He has flown aerogel as a 'GAS-can Lid' payload on STS-47 and is evaluating the results. The Timeband Capture Cell Experiment (TICCE), a Eureca 1 experiment, is also flying aerogel and is scheduled for recovery in late April.

  18. Molecular automata assembly: principles and simulation of bacterial membrane construction.

    Science.gov (United States)

    Lahoz-Beltra, R

    1997-01-01

    The motivation to understand the basic rules and principles governing molecular self-assembly may be relevant to explain in the context of molecular biology the self-organization and biological functions exhibited within cells. This paper presents a molecular automata model to simulate molecular self-assembly introducing the concept of molecular programming to simulate the biological function or operation performed by an assembled molecular state machine. The method is illustrated modelling Escherichia coli membrane construction including the assembly and operation of ATP synthase as well as the assembly of the bacterial flagellar motor. Flagellar motor operation was simulated using a different approach based on state machine definition used in virtual reality systems. The proposed methodology provides a modelling framework for simulation of biological functions performed by cellular components and other biological systems suitable to be modelled as molecular state machines.

  19. Relationship between reaction time, fine motor control, and visual-spatial perception on vigilance and visual-motor tasks in 22q11.2 Deletion Syndrome.

    LENUS (Irish Health Repository)

    Howley, Sarah A

    2012-10-15

    22q11.2 Deletion Syndrome (22q11DS) is a common microdeletion disorder associated with mild to moderate intellectual disability and specific neurocognitive deficits, particularly in visual-motor and attentional abilities. Currently there is evidence that the visual-motor profile of 22q11DS is not entirely mediated by intellectual disability and that these individuals have specific deficits in visual-motor integration. However, the extent to which attentional deficits, such as vigilance, influence impairments on visual motor tasks in 22q11DS is unclear. This study examines visual-motor abilities and reaction time using a range of standardised tests in 35 children with 22q11DS, 26 age-matched typically developing (TD) sibling controls and 17 low-IQ community controls. Statistically significant deficits were observed in the 22q11DS group compared to both low-IQ and TD control groups on a timed fine motor control and accuracy task. The 22q11DS group performed significantly better than the low-IQ control group on an untimed drawing task and were equivalent to the TD control group on point accuracy and simple reaction time tests. Results suggest that visual motor deficits in 22q11DS are primarily attributable to deficits in psychomotor speed which becomes apparent when tasks are timed versus untimed. Moreover, the integration of visual and motor information may be intact and, indeed, represent a relative strength in 22q11DS when there are no time constraints imposed. While this may have significant implications for cognitive remediation strategies for children with 22q11DS, the relationship between reaction time, visual reasoning, cognitive complexity, fine motor speed and accuracy, and graphomotor ability on visual-motor tasks is still unclear.

  20. 50 CFR 622.38 - Landing fish intact.

    Science.gov (United States)

    2010-10-01

    ... that is operating under the respective trip limits. Such cut-off fish also may be sold. A maximum of... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Landing fish intact. 622.38 Section 622.38... Landing fish intact. The operator of a vessel that fishes in the EEZ is responsible for ensuring that fish...

  1. Effects of hydrolysed casein, intact casein and intact whey protein on energy expenditure and appetite regulation

    DEFF Research Database (Denmark)

    Bendtsen, Line Quist; Lorenzen, Janne Kunchel; Gomes, Sisse

    2014-01-01

    Casein and whey differ in amino acid composition and in the rate of absorption; however, the absorption rate of casein can be increased to mimic that of whey by exogenous hydrolysis. The objective of the present study was to compare the effects of hydrolysed casein (HC), intact casein (IC......) and intact whey (IW) on energy expenditure (EE) and appetite regulation, and thereby to investigate the influence of amino acid composition and the rate of absorption. In the present randomised cross-over study, twenty-four overweight and moderately obese young men and women consumed three isoenergetic...

  2. Pharmacokinetics of erythropoietin in intact and anephric dogs

    International Nuclear Information System (INIS)

    Fu, J.S.; Lertora, J.J.; Brookins, J.; Rice, J.C.; Fisher, J.W.

    1988-01-01

    The present studies were performed to determine the pharmacokinetic parameters of erythropoietin in intact and anephric dogs by use of unlabeled crude native erythropoietin (nEp) and iodine 125-labeled purified recombinant erythropoietin (rEp) given by intravenous infusion for 15 minutes. Sephadex G-75 gel filtration was used to confirm that the 125I-rEp molecule remained iodinated in dog plasma during the 24-hour period of these studies. The plasma disappearance of erythropoietin conformed to a biexponential equation for both nEp and 125I-rEp, with the central compartment being larger than the peripheral compartment. The mean distribution half-life of 75.3 +/- 21.2 minutes for nEp was significantly (p less than 0.05) longer than that of 125I-rEp (23.7 +/- 5.0 minutes) in intact dogs. The intercompartmental clearance (CIic) for nEp (0.018 +/- 0.006 L/kg/hr) was significantly smaller than that of 125I-rEp (0.068 +/- 0.018 L/kg/hr) in intact dogs (p less than 0.05). There were no significant differences in apparent volume of distribution, elimination half-life, and elimination clearance (CIe) for nEp and rEp in intact dogs. The mean elimination half-life for 125I-rEp in intact dogs (9.0 +/- 0.6 hours) and anephric dogs (13.8 +/- 1.4 hours) was significantly different (p less than 0.05). The CIe for 125I-rEp in anephric dogs (0.008 +/- 0.001 L/kg/hr) was significantly (p less than 0.05) smaller than that of 125I-rEp in intact dogs (0.011 +/- 0.001 L/kg/hr). There were no significant differences in apparent volume of distribution, distribution half-life, and CIic for 125I-rEp in intact and anephric dogs

  3. Temporary Nerve Block at Selected Digits Revealed Hand Motor Deficits in Grasping Tasks

    Directory of Open Access Journals (Sweden)

    Aude Carteron

    2016-11-01

    Full Text Available Peripheral sensory feedback plays a crucial role in ensuring correct motor execution throughout hand grasp control. Previous studies utilized local anesthesia to deprive somatosensory feedback in the digits or hand, observations included sensorimotor deficits at both corticospinal and peripheral levels. However, the questions of how the disturbed and intact sensory input integrate and interact with each other to assist the motor program execution, and whether the motor coordination based on motor output variability between affected and non-affected elements (e.g., digits becomes interfered by the local sensory deficiency, have not been answered. The current study aims to investigate the effect of peripheral deafferentation through digital nerve blocks at selective digits on motor performance and motor coordination in grasp control. Our results suggested that the absence of somatosensory information induced motor deficits in hand grasp control, as evidenced by reduced maximal force production ability in both local and non-local digits, impairment of force and moment control during object lift and hold, and attenuated motor synergies in stabilizing task performance variables, namely the tangential force and moment of force. These findings implied that individual sensory input is shared across all the digits and the disturbed signal from local sensory channel(s has a more comprehensive impact on the process of the motor output execution in the sensorimotor integration process. Additionally, a feedback control mechanism with a sensation-based component resides in the formation process for the motor covariation structure.

  4. Enhanced Automatic Action Imitation and Intact Imitation-Inhibition in Schizophrenia.

    Science.gov (United States)

    Simonsen, Arndis; Fusaroli, Riccardo; Skewes, Joshua Charles; Roepstorff, Andreas; Campbell-Meiklejohn, Daniel; Mors, Ole; Bliksted, Vibeke

    2018-02-21

    Imitation plays a key role in social learning and in facilitating social interactions and likely constitutes a basic building block of social cognition that supports higher-level social abilities. Recent findings suggest that patients with schizophrenia have imitation impairments that could contribute to the social impairments associated with the disorder. However, extant studies have specifically assessed voluntary imitation or automatic imitation of emotional stimuli without controlling for potential confounders. The imitation impairments seen might therefore be secondary to other cognitive, motoric, or emotional deficits associated with the disorder. To overcome this issue, we used an automatic imitation paradigm with nonemotional stimuli to assess automatic imitation and the top-down modulation of imitation where participants were required to lift one of 2 fingers according to a number shown on the screen while observing the same or the other finger movement. In addition, we used a control task with a visual cue in place of a moving finger, to isolate the effect of observing finger movement from other visual cueing effects. Data from 33 patients (31 medicated) and 40 matched healthy controls were analyzed. Patients displayed enhanced imitation and intact top-down modulation of imitation. The enhanced imitation seen in patients may have been medication induced as larger effects were seen in patients receiving higher antipsychotic doses. In sum, we did not find an imitation impairment in schizophrenia. The results suggest that previous findings of impaired imitation in schizophrenia might have been due to other cognitive, motoric, and/or emotional deficits.

  5. Two Types of Genetic Interaction Implicate the Whirligig Gene of Drosophila Melanogaster in Microtubule Organization in the Flagellar Axoneme

    Science.gov (United States)

    Green, L. L.; Wolf, N.; McDonald, K. L.; Fuller, M. T.

    1990-01-01

    The mutant nc4 allele of whirligig (3-54.4) of Drosophila melanogaster fails to complement mutations in an α-tubulin locus, α1t, mutations in a β-tubulin locus, B2t, or a mutation in the haywire locus. However, wrl fails to map to any of the known α- or β-tubulin genes. The extragenic failure to complement could indicate that the wrl product participates in structural interactions with microtubule proteins. The whirligig locus appears to be haploinsufficient for male fertility. Both a deficiency of wrl and possible loss of function alleles obtained by reverting the failure to complement between wrl(nc4) and B2t(n) are dominant male sterile in a genetic background wild type for tubulin. The dominant male sterility of the revertant alleles is suppressed if the flies are also heterozygous for B2t(n), for a deficiency of α1t, or for the hay(nc2) allele. These results suggest that it is not the absolute level of wrl gene product but its level relative to tubulin or microtubule function that is important for normal spermatogenesis. The phenotype of homozygous wrl mutants suggests that the whirligig product plays a role in postmeiotic spermatid differentiation, possibly in organizing the microtubules of the sperm flagellar axoneme. Flies homozygous for either wrl(nc4) or revertant alleles are viable and female fertile but male sterile. Premeiotic and meiotic stages of spermatogenesis appear normal. However, in post-meiotic stages, flagellar axonemes show loss of the accessory microtubule on the B-subfiber of outer doublet microtubules, outer triplet instead of outer doublet microtubules, and missing central pair microtubules. PMID:2127579

  6. Fulltext PDF

    Indian Academy of Sciences (India)

    Unknown

    The bacterial flagellar motor is a rotary molecular engine ... the sodium ions of the medium (Aizawa 2001), trans- ... Video imaging was used for short dura- ... J. Biosci. 30(4), September 2005. Anindito Sen, Ranjan K Nandi and Amar N Ghosh.

  7. Implicit perceptual-motor skill learning in mild cognitive impairment and Parkinson's disease.

    Science.gov (United States)

    Gobel, Eric W; Blomeke, Kelsey; Zadikoff, Cindy; Simuni, Tanya; Weintraub, Sandra; Reber, Paul J

    2013-05-01

    Implicit skill learning is hypothesized to depend on nondeclarative memory that operates independent of the medial temporal lobe (MTL) memory system and instead depends on cortico striatal circuits between the basal ganglia and cortical areas supporting motor function and planning. Research with the Serial Reaction Time (SRT) task suggests that patients with memory disorders due to MTL damage exhibit normal implicit sequence learning. However, reports of intact learning rely on observations of no group differences, leading to speculation as to whether implicit sequence learning is fully intact in these patients. Patients with Parkinson's disease (PD) often exhibit impaired sequence learning, but this impairment is not universally observed. Implicit perceptual-motor sequence learning was examined using the Serial Interception Sequence Learning (SISL) task in patients with amnestic Mild Cognitive Impairment (MCI; n = 11) and patients with PD (n = 15). Sequence learning in SISL is resistant to explicit learning and individually adapted task difficulty controls for baseline performance differences. Patients with MCI exhibited robust sequence learning, equivalent to healthy older adults (n = 20), supporting the hypothesis that the MTL does not contribute to learning in this task. In contrast, the majority of patients with PD exhibited no sequence-specific learning in spite of matched overall task performance. Two patients with PD exhibited performance indicative of an explicit compensatory strategy suggesting that impaired implicit learning may lead to greater reliance on explicit memory in some individuals. The differences in learning between patient groups provides strong evidence in favor of implicit sequence learning depending solely on intact basal ganglia function with no contribution from the MTL memory system.

  8. Isolation of intact elastin fibers devoid of microfibrils.

    NARCIS (Netherlands)

    Daamen, W.F.; Hafmans, T.G.M.; Veerkamp, J.H.; Kuppevelt, A.H.M.S.M. van

    2005-01-01

    Purification protocols for elastin generally result in greatly damaged elastin fibers and this likely influences the biological response. We here describe a novel protocol for the isolation of elastin whereby the fibers stay intact, and introduce the term "elastin fiber" for intact elastic fibers

  9. Soluble components of the flagellar export apparatus, FliI, FliJ, and FliH, do not deliver flagellin, the major filament protein, from the cytosol to the export gate.

    Science.gov (United States)

    Sajó, Ráchel; Liliom, Károly; Muskotál, Adél; Klein, Agnes; Závodszky, Péter; Vonderviszt, Ferenc; Dobó, József

    2014-11-01

    Flagella, the locomotion organelles of bacteria, extend from the cytoplasm to the cell exterior. External flagellar proteins are synthesized in the cytoplasm and exported by the flagellar type III secretion system. Soluble components of the flagellar export apparatus, FliI, FliH, and FliJ, have been implicated to carry late export substrates in complex with their cognate chaperones from the cytoplasm to the export gate. The importance of the soluble components in the delivery of the three minor late substrates FlgK, FlgL (hook-filament junction) and FliD (filament-cap) has been convincingly demonstrated, but their role in the transport of the major filament component flagellin (FliC) is still unclear. We have used continuous ATPase activity measurements and quartz crystal microbalance (QCM) studies to characterize interactions between the soluble export components and flagellin or the FliC:FliS substrate-chaperone complex. As controls, interactions between soluble export component pairs were characterized providing Kd values. FliC or FliC:FliS did not influence the ATPase activity of FliI alone or in complex with FliH and/or FliJ suggesting lack of interaction in solution. Immobilized FliI, FliH, or FliJ did not interact with FliC or FliC:FliS detected by QCM. The lack of interaction in the fluid phase between FliC or FliC:FliS and the soluble export components, in particular with the ATPase FliI, suggests that cells use different mechanisms for the export of late minor substrates, and the major substrate, FliC. It seems that the abundantly produced flagellin does not require the assistance of the soluble export components to efficiently reach the export gate. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. A Xanthomonas citri subsp citri hypothetical protein related to virulence contains a non-functional HD domain and is implicated in flagellar motility.

    Science.gov (United States)

    Vieira, F C F; Gonçalves, A M; Mendoza, E F R; Ferreira, R M; Costa, M L M; Balbuena, T S; Sebinelli, H G; Ciancaglini, P; Pizauro Junior, J M; Ferro, J A

    2017-08-31

    Citrus canker, caused by the Gram-negative bacterium Xanthomonas citri subsp citri (Xac), severely affects most economically important citrus varieties worldwide. A previous study showed that disruption of the ORF XAC1201 from the Xac 306 strain by transposon Tn5 decreased bacterium virulence in the Rangpur lime host (Citrus limonia L. Osbeck). However, little is known regarding the possible function of the hypothetical protein XAC1201 and how it affects the virulence of Xac 306. Here, we confirmed that disruption of ORF XAC1201 reduces Xac 306 virulence in two different hosts, delaying the onset of typical symptoms. In silico analysis suggested that XAC1201 interacts with the flagellar proteins FliM and FliL, known to be an important factor for virulence. In fact, motility assays revealed that the XAC1201 mutant has a significant difference in motility compared to the wild-type Xac 306. Also, a 3-D structure model revealed modified cofactor binding sites and suggested that XAC1201 has a non-functional HD domain. This hypothesis was confirmed by enzymatic assays performed in purified, XAC1201 recombinant protein expressed in Escherichia coli, which revealed no significant activities previously associated with HD domains for the tested substrates. Thus, the role of the XAC1201 protein in Xac 306 virulence seems to be related to flagellar motility, although a non-classic role for the HD domain cannot be dismissed.

  11. Automatic activation of motor programs by object affordances in patients with Parkinson's disease

    OpenAIRE

    Oguro, Hiroaki; Ward, Robert; Bracewel, Martyn; Hindle, John; Rafal, Robert

    2009-01-01

    Clinical observations of kinesia paradoxica and freezing in patients with Parkinson's disease suggest that the automatic activation of motor programmes by visual stimuli may not require intact basal ganglia function, and that an increased sensitivity to such object affordances may contribute to some symptoms of the disease. Employing a paradigm that measures the degree of interference from object affordances on voluntary actions, we confirm that activation of object affordances are preserved ...

  12. Parasites in motion: flagellum-driven cell motility in African trypanosomes

    Science.gov (United States)

    Hill, Kent L.

    2011-01-01

    SUMMARY Motility of the sleeping sickness parasite, Trypanosoma brucei, impacts disease transmission and pathogenesis. Trypanosome motility is driven by a flagellum that harbors a canonical 9 + 2 axoneme, together with trypanosome-specific elaborations. Trypanosome flagellum biology and motility have been the object of intense research over the last two years. These studies have led to the discovery of a novel form of motility, termed social motility, and provided revision of long-standing models for cell propulsion. Recent work has also uncovered novel structural features and motor proteins associated with the flagellar apparatus and has identified candidate signaling molecules that are predicted to regulate flagellar motility. Together with earlier inventories of flagellar proteins from proteomic and genomic studies, the stage is now set to move forward with functional studies to elucidate molecular mechanisms and investigate parasite motility in the context of host-parasite interactions. PMID:20591724

  13. Flagellar membrane fusion and protein exchange in trypanosomes; a new form of cell-cell communication? [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Simon Imhof

    2016-04-01

    Full Text Available Diverse structures facilitate direct exchange of proteins between cells, including plasmadesmata in plants and tunnelling nanotubes in bacteria and higher eukaryotes.  Here we describe a new mechanism of protein transfer, flagellar membrane fusion, in the unicellular parasite Trypanosoma brucei. When fluorescently tagged trypanosomes were co-cultured, a small proportion of double-positive cells were observed. The formation of double-positive cells was dependent on the presence of extracellular calcium and was enhanced by placing cells in medium supplemented with fresh bovine serum. Time-lapse microscopy revealed that double-positive cells arose by bidirectional protein exchange in the absence of nuclear transfer.  Furthermore, super-resolution microscopy showed that this process occurred in ≤1 minute, the limit of temporal resolution in these experiments. Both cytoplasmic and membrane proteins could be transferred provided they gained access to the flagellum. Intriguingly, a component of the RNAi machinery (Argonaute was able to move between cells, raising the possibility that small interfering RNAs are transported as cargo. Transmission electron microscopy showed that shared flagella contained two axonemes and two paraflagellar rods bounded by a single membrane. In some cases flagellar fusion was partial and interactions between cells were transient. In other cases fusion occurred along the entire length of the flagellum, was stable for several hours and might be irreversible. Fusion did not appear to be deleterious for cell function: paired cells were motile and could give rise to progeny while fused. The motile flagella of unicellular organisms are related to the sensory cilia of higher eukaryotes, raising the possibility that protein transfer between cells via cilia or flagella occurs more widely in nature.

  14. Reorganization of Motor Cortex by Vagus Nerve Stimulation Requires Cholinergic Innervation.

    Science.gov (United States)

    Hulsey, Daniel R; Hays, Seth A; Khodaparast, Navid; Ruiz, Andrea; Das, Priyanka; Rennaker, Robert L; Kilgard, Michael P

    2016-01-01

    Vagus nerve stimulation (VNS) paired with forelimb training drives robust, specific reorganization of movement representations in the motor cortex. The mechanisms that underlie VNS-dependent enhancement of map plasticity are largely unknown. The cholinergic nucleus basalis (NB) is a critical substrate in cortical plasticity, and several studies suggest that VNS activates cholinergic circuitry. We examined whether the NB is required for VNS-dependent enhancement of map plasticity in the motor cortex. Rats were trained to perform a lever pressing task and then received injections of the immunotoxin 192-IgG-saporin to selectively lesion cholinergic neurons of the NB. After lesion, rats underwent five days of motor training during which VNS was paired with successful trials. At the conclusion of behavioral training, intracortical microstimulation was used to document movement representations in motor cortex. VNS paired with forelimb training resulted in a substantial increase in the representation of proximal forelimb in rats with an intact NB compared to untrained controls. NB lesions prevent this VNS-dependent increase in proximal forelimb area and result in representations similar to untrained controls. Motor performance was similar between groups, suggesting that differences in forelimb function cannot account for the difference in proximal forelimb representation. Together, these findings indicate that the NB is required for VNS-dependent enhancement of plasticity in the motor cortex and may provide insight into the mechanisms that underlie the benefits of VNS therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Impaired competence in flagellar mutants of Bacillus subtilis is connected to the regulatory network governed by DegU

    DEFF Research Database (Denmark)

    Hölscher, Theresa; Schiklang, Tina; Dragos, Anna

    2018-01-01

    The competent state is a developmentally distinct phase, in which bacteria are able to take up and integrate exogenous DNA into their genome. Bacillus subtilis is one of the naturally competent bacterial species and the domesticated laboratory strain 168 is easily transformable. In this study, we...... report a reduced transformation frequency of B. subtilis mutants lacking functional and structural flagellar components. This includes hag, the gene encoding the flagellin protein forming the filament of the flagellum. We confirm that the observed decrease of the transformation frequency is due...... a close link between motility and natural competence in B. subtilis suggesting that hindrance in motility has great impact on differentiation of this bacterium not restricted only to the transition towards sessile growth stage....

  16. Right lower limb apraxia in a patient with left supplementary motor area infarction: intactness of the corticospinal tract confirmed by transcranial magnetic stimulation

    Directory of Open Access Journals (Sweden)

    Min Cheol Chang

    2015-01-01

    Full Text Available We reported a 50-year-old female patient with left supplementary motor area infarction who presented right lower limb apraxia and investigated the possible causes using transcranial magnetic stimulation. The patient was able to walk and climb stairs spontaneously without any assistance at 3 weeks after onset. However, she was unable to intentionally move her right lower limb although she understood what she supposed to do. The motor evoked potential evoked by transcranial magnetic stimulation from the right lower limb was within the normal range, indicating that the corticospinal tract innervating the right lower limb was uninjured. Thus, we thought that her motor dysfunction was not induced by motor weakness, and confirmed her symptoms as apraxia. In addition, these results also suggest that transcranial magnetic stimulation is helpful for diagnosing apraxia.

  17. Sensorimotor nucleus NIf is necessary for auditory processing but not vocal motor output in the avian song system.

    Science.gov (United States)

    Cardin, Jessica A; Raksin, Jonathan N; Schmidt, Marc F

    2005-04-01

    Sensorimotor integration in the avian song system is crucial for both learning and maintenance of song, a vocal motor behavior. Although a number of song system areas demonstrate both sensory and motor characteristics, their exact roles in auditory and premotor processing are unclear. In particular, it is unknown whether input from the forebrain nucleus interface of the nidopallium (NIf), which exhibits both sensory and premotor activity, is necessary for both auditory and premotor processing in its target, HVC. Here we show that bilateral NIf lesions result in long-term loss of HVC auditory activity but do not impair song production. NIf is thus a major source of auditory input to HVC, but an intact NIf is not necessary for motor output in adult zebra finches.

  18. Autism Spectrum Disorder and intact executive functioning.

    Science.gov (United States)

    Ferrara, R; Ansermet, F; Massoni, F; Petrone, L; Onofri, E; Ricci, P; Archer, T; Ricci, S

    2016-01-01

    Earliest notions concerning autism (Autism Spectrum Disorders, ASD) describe the disturbance in executive functioning. Despite altered definition, executive functioning, expressed as higher cognitive skills required complex behaviors linked to the prefrontal cortex, are defective in autism. Specific difficulties in children presenting autism or verbal disabilities at executive functioning levels have been identified. Nevertheless, the developmental deficit of executive functioning in autism is highly diversified with huge individual variation and may even be absent. The aim of the present study to examine the current standing of intact executive functioning intact in ASD. Analysis of ASD populations, whether high-functioning, Asperger's or autism Broad Phenotype, studied over a range of executive functions including response inhibition, planning, cognitive flexibility, cognitive inhibition, and alerting networks indicates an absence of damage/impairment compared to the typically-developed normal control subjects. These findings of intact executive functioning in ASD subjects provide a strong foundation on which to construct applications for growth environments and the rehabilitation of autistic subjects.

  19. Protein Synthesis Inhibition in the Peri-Infarct Cortex Slows Motor Recovery in Rats.

    Science.gov (United States)

    Schubring-Giese, Maximilian; Leemburg, Susan; Luft, Andreas Rüdiger; Hosp, Jonas Aurel

    2016-01-01

    Neuroplasticity and reorganization of brain motor networks are thought to enable recovery of motor function after ischemic stroke. Especially in the cortex surrounding the ischemic scar (i.e., peri-infarct cortex), evidence for lasting reorganization has been found at the level of neurons and networks. This reorganization depends on expression of specific genes and subsequent protein synthesis. To test the functional relevance of the peri-infarct cortex for recovery we assessed the effect of protein synthesis inhibition within this region after experimental stroke. Long-Evans rats were trained to perform a skilled-reaching task (SRT) until they reached plateau performance. A photothrombotic stroke was induced in the forelimb representation of the primary motor cortex (M1) contralateral to the trained paw. The SRT was re-trained after stroke while the protein synthesis inhibitor anisomycin (ANI) or saline were injected into the peri-infarct cortex through implanted cannulas. ANI injections reduced protein synthesis within the peri-infarct cortex by 69% and significantly impaired recovery of reaching performance through re-training. Improvement of motor performance within a single training session remained intact, while improvement between training sessions was impaired. ANI injections did not affect infarct size. Thus, protein synthesis inhibition within the peri-infarct cortex impairs recovery of motor deficits after ischemic stroke by interfering with consolidation of motor memory between training sessions but not short-term improvements within one session.

  20. Cationic amino acid uptake constitutes a metabolic regulation mechanism and occurs in the flagellar pocket of Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Mariana R Miranda

    Full Text Available Trypanosomatids' amino acid permeases are key proteins in parasite metabolism since they participate in the adaptation of parasites to different environments. Here, we report that TcAAP3, a member of a Trypanosoma cruzi multigene family of permeases, is a bona fide arginine transporter. Most higher eukaryotic cells incorporate cationic amino acids through a single transporter. In contrast, T. cruzi can recognize and transport cationic amino acids by mono-specific permeases since a 100-fold molar excess of lysine could not affect the arginine transport in parasites that over-express the arginine permease (TcAAP3 epimastigotes. In order to test if the permease activity regulates downstream processes of the arginine metabolism, the expression of the single T. cruzi enzyme that uses arginine as substrate, arginine kinase, was evaluated in TcAAP3 epimastigotes. In this parasite model, intracellular arginine concentration increases 4-folds and ATP level remains constant until cultures reach the stationary phase of growth, with decreases of about 6-folds in respect to the controls. Interestingly, Western Blot analysis demonstrated that arginine kinase is significantly down-regulated during the stationary phase of growth in TcAAP3 epimastigotes. This decrease could represent a compensatory mechanism for the increase in ATP consumption as a consequence of the displacement of the reaction equilibrium of arginine kinase, when the intracellular arginine concentration augments and the glucose from the medium is exhausted. Using immunofluorescence techniques we also determined that TcAAP3 and the specific lysine transporter TcAAP7 co-localize in a specialized region of the plasma membrane named flagellar pocket, staining a single locus close to the flagellar pocket collar. Taken together these data suggest that arginine transport is closely related to arginine metabolism and cell energy balance. The clinical relevance of studying trypanosomatids' permeases

  1. Activity of Proteus mirabilis FliL is viscosity dependent and requires extragenic DNA.

    Science.gov (United States)

    Lee, Yi-Ying; Patellis, Julius; Belas, Robert

    2013-02-01

    Proteus mirabilis is a urinary tract pathogen and well known for its ability to move over agar surfaces by flagellum-dependent swarming motility. When P. mirabilis encounters a highly viscous environment, e.g., an agar surface, it differentiates from short rods with few flagella to elongated, highly flagellated cells that lack septa and contain multiple nucleoids. The bacteria detect a surface by monitoring the rotation of their flagellar motors. This process involves an enigmatic flagellar protein called FliL, the first gene in an operon (fliLMNOPQR) that encodes proteins of the flagellar rotor switch complex and flagellar export apparatus. We used a fliL knockout mutant to gain further insight into the function of FliL. Loss of FliL results in cells that cannot swarm (Swr(-)) but do swim (Swm(+)) and produces cells that look like wild-type swarmer cells, termed "pseudoswarmer cells," that are elongated, contain multiple nucleoids, and lack septa. Unlike swarmer cells, pseudoswarmer cells are not hyperflagellated due to reduced expression of flaA (the gene encoding flagellin), despite an increased transcription of both flhD and fliA, two positive regulators of flagellar gene expression. We found that defects in fliL prevent viscosity-dependent sensing of a surface and viscosity-dependent induction of flaA transcription. Studies with fliL cells unexpectedly revealed that the fliL promoter, fliL coding region, and a portion of fliM DNA are needed to complement the Swr(-) phenotype. The data support a dual role for FliL as a critical link in sensing a surface and in the maintenance of flagellar rod integrity.

  2. Flagellar coordination in Chlamydomonas cells held on micropipettes.

    Science.gov (United States)

    Rüffer, U; Nultsch, W

    1998-01-01

    The two flagella of Chlamydomonas are known to beat synchronously: During breaststroke beating they are generally coordinated in a bilateral way while in shock responses during undulatory beating coordination is mostly parallel [Rüffer and Nultsch, 1995: Botanica Acta 108:169-276]. Analysis of a great number of shock responses revealed that in undulatory beats also periods of bilateral coordination are found and that the coordination type may change several times during a shock response, without concomitant changes of the beat envelope and the beat period. In normal wt cells no coordination changes are found during breaststroke beating, but only short temporary asynchronies: During 2 or 3 normal beats of the cis flagellum, the trans flagellum performs 3 or 4 flat beats with a reduced beat envelope and a smaller beat period, resulting in one additional trans beat. Long periods with flat beats of the same shape and beat period are found in both flagella of the non-phototactic mutant ptx1 and in defective wt 622E cells. During these periods, the coordination is parallel, the two flagella beat alternately. A correlation between normal asynchronous trans beats and the parallel-coordinated beats in the presumably cis defective cells and also the undulatory beats is discussed. In the cis defective cells, a perpetual spontaneous change between parallel beats with small beat periods (higher beat frequency) and bilateral beats with greater beat periods (lower beat frequency) are observed and render questionable the existence of two different intrinsic beat frequencies of the two flagella cis and trans. Asynchronies occur spontaneously but may also be induced by light changes, either step-up or step-down, but not by both stimuli in turn as breaststroke flagellar photoresponses (BFPRs). Asynchronies are not involved in phototaxis. They are independent of the BFPRs, which are supposed to be the basis of phototaxis. Both types of coordination must be assumed to be regulated

  3. Robotic set-up to quantify hand-eye behavior in motor execution and learning of children with autism spectrum disorder.

    Science.gov (United States)

    Casellato, Claudia; Gandolla, Marta; Crippa, Alessandro; Pedrocchi, Alessandra

    2017-07-01

    Autism spectrum disorder (ASD) is a multifaceted neurodevelopmental disorder characterized by a persistence of social and communication impairment, and restricted and repetitive behaviors. However, motor disorders have also been described, but not objectively assessed. Most studies showed inefficient eye-hand coordination and motor learning in children with ASD; in other experiments, mechanisms of acquisition of internal models in self-generated movements appeared to be normal in autism. In this framework, we have developed a robotic protocol, recording gaze and hand data during upper limb tasks, in which a haptic pen-like handle is moved along specific trajectories displayed on the screen. The protocol includes trials of reaching under a perturbing force field and catching moving targets, with or without visual availability of the whole path. We acquired 16 typically-developing scholar-age children and one child with ASD as a case study. Speed-accuracy tradeoff, motor performance, and gaze-hand spatial coordination have been evaluated. Compared to typically developing peers, in the force field sequence, the child with ASD showed an intact but delayed learning, and more variable gazehand patterns. In the catching trials, he showed less efficient movements, but an intact capability of exploiting the available a-priori plan. The proposed protocol represents a powerful tool, easily tunable, for quantitative (longitudinal) assessment, and for subject-tailored training in ASD.

  4. Intact collagen and atelocollagen sponges: Characterization and ESEM observation

    International Nuclear Information System (INIS)

    Ruozi, Barbara; Tosi, Giovanni; Leo, Eliana; Parma, Bruna; Vismara, Susanna; Forni, Flavio; Vandelli, Maria Angela

    2007-01-01

    In this study we have investigated the chemical-physical and morphological properties of intact and atelocollagen sponges used for tissue engineering. The porous sponges were prepared by lyophilization and their physico-chemical characteristics (water binding capacity, denaturing temperature, amino group content) were investigated. Considering the importance of the 'in vivo' interactions between these sponges and the tissue, our attention was addressed (a) to clarify the relationships between the morphology and the amount of water absorbed and (b) to evaluate the influence of pepsin-alkaline treatment on the reorganization of the atelocollagen fibres. Conventional scanning electron microscopy (SEM) and environmental scanning electron microscopy (ESEM) were employed to study the morphology and wetting behaviour of the intact and atelocollagen sponges. The observations by SEM indicated remarkable differences both in the structure and dimension of the pores between intact and atelocollagen sponges. At the data are related to a different water binding capacity. However, the ESEM observations, achieved by changing the relative humidity in the operative chamber, demonstrated that the water adsorbed can be removed with major difficulty from atelocollagen sponges than from intact ones

  5. Two new species of Piaroa (Arachnida: Schizomida, Hubbardiidae) from Colombia, with comments on the genus taxonomy and the flagellar setae pattern of Hubbardiinae.

    Science.gov (United States)

    Moreno-González, Jairo A; Delgado-Santa, Leonardo; De Armas, Luis F

    2014-08-14

    Two new species of the genus Piaroa Villarreal, Tourinho & Giupponi, 2008, P. escalerete sp. nov. and P. bacata sp. nov. are described from Valle del Cauca, and Cundinamarca departments, Colombia, respectively. The female flagellum is fully illustrated for a Piaroa species for the first time; the generic diagnosis is also emended and the relationships of the new species with those previously described are discussed. New characters for Piaroa species, a new nomenclature for the chitinized arch and a reinterpretation of the Hubbardiinae flagellar setae pattern are proposed. A distribution map of the known species of Piaroa is provided. 

  6. Crystallization of FcpA from Leptospira, a novel flagellar protein that is essential for pathogenesis.

    Science.gov (United States)

    San Martin, Fabiana; Mechaly, Ariel E; Larrieux, Nicole; Wunder, Elsio A; Ko, Albert I; Picardeau, Mathieu; Trajtenberg, Felipe; Buschiazzo, Alejandro

    2017-03-01

    The protein FcpA is a unique component of the flagellar filament of spirochete bacteria belonging to the genus Leptospira. Although it plays an essential role in translational motility and pathogenicity, no structures of FcpA homologues are currently available in the PDB. Its three-dimensional structure will unveil the novel motility mechanisms that render pathogenic Leptospira particularly efficient at invading and disseminating within their hosts, causing leptospirosis in humans and animals. FcpA from L. interrogans was purified and crystallized, but despite laborious attempts no useful X ray diffraction data could be obtained. This challenge was solved by expressing a close orthologue from the related saprophytic species L. biflexa. Three different crystal forms were obtained: a primitive and a centred monoclinic form, as well as a hexagonal variant. All forms diffracted X-rays to suitable resolutions for crystallographic analyses, with the hexagonal type typically reaching the highest limits of 2.0 Å and better. A variation of the quick-soaking procedure resulted in an iodide derivative that was instrumental for single-wavelength anomalous diffraction methods.

  7. Imaging of the 3D dynamics of flagellar beating in human sperm.

    Science.gov (United States)

    Silva-Villalobos, F; Pimentel, J A; Darszon, A; Corkidi, G

    2014-01-01

    The study of the mechanical and environmental factors that regulate a fundamental event such as fertilization have been subject of multiple studies. Nevertheless, the microscopical size of the spermatozoa and the high beating frequency of their flagella (up to 20 Hz) impose a series of technological challenges for the study of the mechanical factors implicated. Traditionally, due to the inherent characteristics of the rapid sperm movement, and to the technological limitations of microscopes (optical or confocal) to follow in three dimensions (3D) their movement, the analysis of their dynamics has been studied in two dimensions, when the head is confined to a surface. Flagella propel sperm and while their head can be confined to a surface, flagellar movement is not restricted to 2D, always displaying 3D components. In this work, we present a highly novel and useful tool to analyze sperm flagella dynamics in 3D. The basis of the method is a 100 Hz oscillating objective mounted on a bright field optical microscope covering a 16 microns depth space at a rate of ~ 5000 images per second. The best flagellum focused subregions were associated to their respective Z real 3D position. Unprecedented graphical results making evident the 3D movement of the flagella are shown in this work and supplemental material illustrating a 3D animation using the obtained experimental results is also included.

  8. Interaction between the flagellar pocket collar and the hook complex via a novel microtubule-binding protein in Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Anna Albisetti

    2017-11-01

    Full Text Available Trypanosoma brucei belongs to a group of unicellular, flagellated parasites that are responsible for human African trypanosomiasis. An essential aspect of parasite pathogenicity is cytoskeleton remodelling, which occurs during the life cycle of the parasite and is accompanied by major changes in morphology and organelle positioning. The flagellum originates from the basal bodies and exits the cell body through the flagellar pocket (FP but remains attached to the cell body via the flagellum attachment zone (FAZ. The FP is an invagination of the pellicular membrane and is the sole site for endo- and exocytosis. The FAZ is a large complex of cytoskeletal proteins, plus an intracellular set of four specialised microtubules (MtQ that elongate from the basal bodies to the anterior end of the cell. At the distal end of the FP, an essential, intracellular, cytoskeletal structure called the flagellar pocket collar (FPC circumvents the flagellum. Overlapping the FPC is the hook complex (HC (a sub-structure of the previously named bilobe that is also essential and is thought to be involved in protein FP entry. BILBO1 is the only functionally characterised FPC protein and is necessary for FPC and FP biogenesis. Here, we used a combination of in vitro and in vivo approaches to identify and characterize a new BILBO1 partner protein-FPC4. We demonstrate that FPC4 localises to the FPC, the HC, and possibly to a proximal portion of the MtQ. We found that the C-terminal domain of FPC4 interacts with the BILBO1 N-terminal domain, and we identified the key amino acids required for this interaction. Interestingly, the FPC4 N-terminal domain was found to bind microtubules. Over-expression studies highlight the role of FPC4 in its association with the FPC, HC and FPC segregation. Our data suggest a tripartite association between the FPC, the HC and the MtQ.

  9. Measurement of diffusive properties of intact rock

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, K B

    1996-12-01

    In the Postclosure Assessment of a Reference System for the Disposal of Canada`s Nuclear Fuel Waste (Goodwin et al. 1994) the disposal vault is assumed to be surrounded by a zone of intact rock, referred to as the `exclusion zone.` A sensitivity analysis of the relative effectiveness of the several engineered and natural barriers that contribute to the safety of the reference disposal system has shown that this zone of intact rock is the most effective of these barriers to the movement of radionuclides through the reference system. Peer review of the geosphere model used in the case study for the EIS (Environmental Impact Statement) of the Canadian Nuclear Fuel Waste Management Program has identified the need to quantify the properties of the intact rock surrounding the disposal vault that would control the transport of radionuclides by diffusion. The Postclosure Assessment also identified the need for appropriate values of the free water diffusion coefficient (D{sub o}) for {sup 129}1 and {sup 14}C. The measurement of rock resistivity allows the calculation of the Formation Factor for a rock This review describes the Formation Factor, diffusivity, permeability, and porosity, and how these properties might be measured or inferred for insitu rock under the conditions that apply to the intact rock surrounding a potential disposal vault. The importance of measuring the intrinsic diffusion coefficient (D{sup i}) of diffusing species under solution salinities simulating those of groundwaters is emphasised, and a method of measurement is described that is independent of the diffusing medium, and which would be appropriate for measurements made in chemically complex media such as groundwaters. (author). 95 refs., 4 tabs., 39 figs.

  10. Measurement of diffusive properties of intact rock

    International Nuclear Information System (INIS)

    Harvey, K.B.

    1996-12-01

    In the Postclosure Assessment of a Reference System for the Disposal of Canada's Nuclear Fuel Waste (Goodwin et al. 1994) the disposal vault is assumed to be surrounded by a zone of intact rock, referred to as the 'exclusion zone.' A sensitivity analysis of the relative effectiveness of the several engineered and natural barriers that contribute to the safety of the reference disposal system has shown that this zone of intact rock is the most effective of these barriers to the movement of radionuclides through the reference system. Peer review of the geosphere model used in the case study for the EIS (Environmental Impact Statement) of the Canadian Nuclear Fuel Waste Management Program has identified the need to quantify the properties of the intact rock surrounding the disposal vault that would control the transport of radionuclides by diffusion. The Postclosure Assessment also identified the need for appropriate values of the free water diffusion coefficient (D o ) for 129 1 and 14 C. The measurement of rock resistivity allows the calculation of the Formation Factor for a rock This review describes the Formation Factor, diffusivity, permeability, and porosity, and how these properties might be measured or inferred for insitu rock under the conditions that apply to the intact rock surrounding a potential disposal vault. The importance of measuring the intrinsic diffusion coefficient (D i ) of diffusing species under solution salinities simulating those of groundwaters is emphasised, and a method of measurement is described that is independent of the diffusing medium, and which would be appropriate for measurements made in chemically complex media such as groundwaters. (author). 95 refs., 4 tabs., 39 figs

  11. Motor skill learning, retention, and control deficits in Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Lisa Katharina Pendt

    Full Text Available Parkinson's disease, which affects the basal ganglia, is known to lead to various impairments of motor control. Since the basal ganglia have also been shown to be involved in learning processes, motor learning has frequently been investigated in this group of patients. However, results are still inconsistent, mainly due to skill levels and time scales of testing. To bridge across the time scale problem, the present study examined de novo skill learning over a long series of practice sessions that comprised early and late learning stages as well as retention. 19 non-demented, medicated, mild to moderate patients with Parkinson's disease and 19 healthy age and gender matched participants practiced a novel throwing task over five days in a virtual environment where timing of release was a critical element. Six patients and seven control participants came to an additional long-term retention testing after seven to nine months. Changes in task performance were analyzed by a method that differentiates between three components of motor learning prominent in different stages of learning: Tolerance, Noise and Covariation. In addition, kinematic analysis related the influence of skill levels as affected by the specific motor control deficits in Parkinson patients to the process of learning. As a result, patients showed similar learning in early and late stages compared to the control subjects. Differences occurred in short-term retention tests; patients' performance constantly decreased after breaks arising from poorer release timing. However, patients were able to overcome the initial timing problems within the course of each practice session and could further improve their throwing performance. Thus, results demonstrate the intact ability to learn a novel motor skill in non-demented, medicated patients with Parkinson's disease and indicate confounding effects of motor control deficits on retention performance.

  12. Electrical stimulation of transplanted motoneurons improves motor unit formation

    Science.gov (United States)

    Liu, Yang; Grumbles, Robert M.

    2014-01-01

    Motoneurons die following spinal cord trauma and with neurological disease. Intact axons reinnervate nearby muscle fibers to compensate for the death of motoneurons, but when an entire motoneuron pool dies, there is complete denervation. To reduce denervation atrophy, we have reinnervated muscles in Fisher rats from local transplants of embryonic motoneurons in peripheral nerve. Since growth of axons from embryonic neurons is activity dependent, our aim was to test whether brief electrical stimulation of the neurons immediately after transplantation altered motor unit numbers and muscle properties 10 wk later. All surgical procedures and recordings were done in anesthetized animals. The muscle consequences of motoneuron death were mimicked by unilateral sciatic nerve section. One week later, 200,000 embryonic day 14 and 15 ventral spinal cord cells, purified for motoneurons, were injected into the tibial nerve 10–15 mm from the gastrocnemii muscles as the only neuron source for muscle reinnervation. The cells were stimulated immediately after transplantation for up to 1 h using protocols designed to examine differential effects due to pulse number, stimulation frequency, pattern, and duration. Electrical stimulation that included short rests and lasted for 1 h resulted in higher motor unit counts. Muscles with higher motor unit counts had more reinnervated fibers and were stronger. Denervated muscles had to be stimulated directly to evoke contractions. These results show that brief electrical stimulation of embryonic neurons, in vivo, has long-term effects on motor unit formation and muscle force. This muscle reinnervation provides the opportunity to use patterned electrical stimulation to produce functional movements. PMID:24848463

  13. Patterns of motor activity in the isolated nerve cord of the octopus arm.

    Science.gov (United States)

    Gutfreund, Yoram; Matzner, Henry; Flash, Tamar; Hochner, Binyamin

    2006-12-01

    The extremely flexible octopus arm provides a unique opportunity for studying movement control in a highly redundant motor system. We describe a novel preparation that allows analysis of the peripheral nervous system of the octopus arm and its interaction with the muscular and mechanosensory elements of the arm's intrinsic muscular system. First we examined the synaptic responses in muscle fibers to identify the motor pathways from the axial nerve cord of the arm to the surrounding musculature. We show that the motor axons project to the muscles via nerve roots originating laterally from the arm nerve cord. The motor field of each nerve is limited to the region where the nerve enters the arm musculature. The same roots also carry afferent mechanosensory information from the intrinsic muscle to the axial nerve cord. Next, we characterized the pattern of activity generated in the dorsal roots by electrically stimulating the axial nerve cord. The evoked activity, although far reaching and long lasting, cannot alone account for the arm extension movements generated by similar electrical stimulation. The mismatch between patterns of activity in the isolated cord and in an intact arm may stem from the involvement of mechanosensory feedback in natural arm extension.

  14. Bringing up the rear: new premotor interneurons add regional complexity to a segmentally distributed motor pattern

    Science.gov (United States)

    Norris, Brian J.; Doloc-Mihu, Anca; Calabrese, Ronald L.

    2011-01-01

    Central pattern generators (CPGs) pace and pattern many rhythmic activities. We have uncovered a new module in the heartbeat CPG of leeches that creates a regional difference in this segmentally distributed motor pattern. The core CPG consists of seven identified pairs and one unidentified pair of heart interneurons of which 5 pairs are premotor and inhibit 16 pairs of heart motor neurons. The heartbeat CPG produces a side-to-side asymmetric pattern of activity of the premotor heart interneurons corresponding to an asymmetric fictive motor pattern and an asymmetric constriction pattern of the hearts with regular switches between the two sides. The premotor pattern progresses from rear to front on one side and nearly synchronously on the other; the motor pattern shows corresponding intersegmental coordination, but only from segment 15 forward. In the rearmost segments the fictive motor pattern and the constriction pattern progress from front to rear on both sides and converge in phase. Modeling studies suggested that the known inhibitory inputs to the rearmost heart motor neurons were insufficient to account for this activity. We therefore reexamined the constriction pattern of intact leeches. We also identified electrophysiologically two additional pairs of heart interneurons in the rear. These new heart interneurons make inhibitory connections with the rear heart motor neurons, are coordinated with the core heartbeat CPG, and are dye-coupled to their contralateral homologs. Their strong inhibitory connections with the rearmost heart motor neurons and the small side-to-side phase difference of their bursting contribute to the different motor and beating pattern observed in the animal's rear. PMID:21775711

  15. Independent Analysis of the Flagellum Surface and Matrix Proteomes Provides Insight into Flagellum Signaling in Mammalian-infectious Trypanosoma brucei*

    Science.gov (United States)

    Oberholzer, Michael; Langousis, Gerasimos; Nguyen, HoangKim T.; Saada, Edwin A.; Shimogawa, Michelle M.; Jonsson, Zophonias O.; Nguyen, Steven M.; Wohlschlegel, James A.; Hill, Kent L.

    2011-01-01

    The flagellum of African trypanosomes is an essential and multifunctional organelle that functions in motility, cell morphogenesis, and host-parasite interaction. Previous studies of the trypanosome flagellum have been limited by the inability to purify flagella without first removing the flagellar membrane. This limitation is particularly relevant in the context of studying flagellum signaling, as signaling requires surface-exposed proteins in the flagellar membrane and soluble signaling proteins in the flagellar matrix. Here we employ a combination of genetic and mechanical approaches to purify intact flagella from the African trypanosome, Trypanosoma brucei, in its mammalian-infectious stage. We combined flagellum purification with affinity-purification of surface-exposed proteins to conduct independent proteomic analyses of the flagellum surface and matrix fractions. The proteins identified encompass a broad range of molecular functionalities, including many predicted to function in signaling. Immunofluorescence and RNA interference studies demonstrate flagellum localization and function for proteins identified and provide insight into mechanisms of flagellum attachment and motility. The flagellum surface proteome includes many T. brucei-specific proteins and is enriched for proteins up-regulated in the mammalian-infectious stage of the parasite life-cycle. The combined results indicate that the flagellum surface presents a diverse and dynamic host-parasite interface that is well-suited for host-parasite signaling. PMID:21685506

  16. Diffusion as a Ruler: Modeling Kinesin Diffusion as a Length Sensor for Intraflagellar Transport.

    Science.gov (United States)

    Hendel, Nathan L; Thomson, Matthew; Marshall, Wallace F

    2018-02-06

    An important question in cell biology is whether cells are able to measure size, either whole cell size or organelle size. Perhaps cells have an internal chemical representation of size that can be used to precisely regulate growth, or perhaps size is just an accident that emerges due to constraint of nutrients. The eukaryotic flagellum is an ideal model for studying size sensing and control because its linear geometry makes it essentially one-dimensional, greatly simplifying mathematical modeling. The assembly of flagella is regulated by intraflagellar transport (IFT), in which kinesin motors carry cargo adaptors for flagellar proteins along the flagellum and then deposit them at the tip, lengthening the flagellum. The rate at which IFT motors are recruited to begin transport into the flagellum is anticorrelated with the flagellar length, implying some kind of communication between the base and the tip and possibly indicating that cells contain some mechanism for measuring flagellar length. Although it is possible to imagine many complex scenarios in which additional signaling molecules sense length and carry feedback signals to the cell body to control IFT, might the already-known components of the IFT system be sufficient to allow length dependence of IFT? Here we investigate a model in which the anterograde kinesin motors unbind after cargo delivery, diffuse back to the base, and are subsequently reused to power entry of new IFT trains into the flagellum. By mathematically modeling and simulating such a system, we are able to show that the diffusion time of the motors can in principle be sufficient to serve as a proxy for length measurement. We found that the diffusion model can not only achieve a stable steady-state length without the addition of any other signaling molecules or pathways, but also is able to produce the anticorrelation between length and IFT recruitment rate that has been observed in quantitative imaging studies. Copyright © 2017 Biophysical

  17. Liver polyribosome distribution in intact and adrenalectomized rats exposed to. gamma. radiation

    Energy Technology Data Exchange (ETDEWEB)

    Yatvin, M B; Abdel-Halim, M N [Wisconsin Univ., Madison (USA). Dept. of Radiology; Wisconsin Univ., Madison (USA). Dept. of Human Oncology)

    1978-06-01

    The mechanism(s) by which gamma radiation influences liver polyribosome distribution was studied in groups of intact and adrenalectomized male rats. A shift from light to heavy aggregates occurred in the polyribosomes of both intact and adrenalectomized rats after they were exposed to gamma rays. In irradiated adrenalectomized rats, however, the shift to heavier aggregates was not as great as that which occurred in irradiated adrenal-intact animals. Subcutaneous injection of cortisone acetate (10 mg/100 g body weight) also altered the liver polyribosome patterns of both intact and adrenalectomized rats within 8 hours of its administration. The shift which occurred following cortisone administration, however, was less striking than that seen after irradiation only. Thus, although adrenal glucocorticoids contribute to the radiation-indu ied shift in liver polyribosomes in adrenal-intact rats, other factors appear to be involved, since the shift is also obtained in adrenalectomized animals.

  18. Sleep spindles: a physiological marker of age-related changes in gray matter in brain regions supporting motor skill memory consolidation.

    Science.gov (United States)

    Fogel, Stuart; Vien, Catherine; Karni, Avi; Benali, Habib; Carrier, Julie; Doyon, Julien

    2017-01-01

    Sleep is necessary for the optimal consolidation of procedural learning, and in particular, for motor sequential skills. Motor sequence learning remains intact with age, but sleep-dependent consolidation is impaired, suggesting that memory deficits for procedural skills are specifically impacted by age-related changes in sleep. Age-related changes in spindles may be responsible for impaired motor sequence learning consolidation, but the morphological basis for this deficit is unknown. Here, we found that gray matter in the hippocampus and cerebellum was positively correlated with both sleep spindles and offline improvements in performance in young participants but not in older participants. These results suggest that age-related changes in gray matter in the hippocampus relate to spindles and may underlie age-related deficits in sleep-related motor sequence memory consolidation. In this way, spindles can serve as a biological marker for structural brain changes and the related memory deficits in older adults. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Sorption of cesium in intact rock

    International Nuclear Information System (INIS)

    Puukko, E.

    2014-04-01

    The mass distribution coefficient K d is used in performance assessment (PA) to describe sorption of a radionuclide on rock. The R d is determined using crushed rock which causes uncertainty in converting the R d values to K d values for intact rock. This work describes a method to determine the equilibrium of sorption on intact rock. The rock types of the planned Olkiluoto waste disposal site were T-series mica gneiss (T-MGN), T-series tonalite granodiorite granite gneiss (T-TGG), P-series tonalite granodiorite granite gneiss (P-TGG) and pegmatitic granite (PGR). These rocks contain different amount of biotite which is the main sorbing mineral. The sorption of cesium on intact rock slices was studied by applying an electrical field to speed up migration of cesium into the rock. Cesium is in the solution as a noncomplex cation Cs + and it is sorbed by ion exchange. The tracer used in the experiments was 134 Cs. The experimental sorption on the intact rock is compared with values calculated using the in house cation exchange sorption model (HYRL model) in PHREEQC program. The observed sorption on T-MGN and T-TGG rocks was close to the calculated values. Two PGR samples were from a depth of 70 m and three samples were from a depth of 150 m. Cesium sorbed more than predicted on the two 70 m PGR samples. The sorption of Cs on the three 150 m PGR samples was small which was consistent with the calculations. The pegmatitic granite PGR has the smallest content of biotite of the four rock types. In the case of P-TGG rock the observed values of sorption were only half of the calculated values. Two kind of slices were cut from P-TGG drill core. The slices were against and to the direction of the foliation of the biotite rims. The sorption of cesium on P-TGG rock was same in both cases. The results indicated that there was no effect of the directions of the electric field and the foliation of biotite in the P-TGG rock. (orig.)

  20. Automatic activation of motor programs by object affordances in patients with Parkinson's disease.

    Science.gov (United States)

    Oguro, Hiroaki; Ward, Robert; Bracewel, Martyn; Hindle, John; Rafal, Robert

    2009-09-29

    Clinical observations of kinesia paradoxica and freezing in patients with Parkinson's disease suggest that the automatic activation of motor programmes by visual stimuli may not require intact basal ganglia function, and that an increased sensitivity to such object affordances may contribute to some symptoms of the disease. Employing a paradigm that measures the degree of interference from object affordances on voluntary actions, we confirm that activation of object affordances are preserved in Parkinson's disease, but find no evidence that there is an increased sensitivity to the effects of object affordances on voluntary action.

  1. Automatic activation of motor programs by object affordances in patients with Parkinson's disease

    Science.gov (United States)

    Oguro, Hiroaki; Ward, Robert; Bracewel, Martyn; Hindle, John; Rafal, Robert

    2009-01-01

    Clinical observations of kinesia paradoxica and freezing in patients with Parkinson's disease suggest that the automatic activation of motor programmes by visual stimuli may not require intact basal ganglia function, and that an increased sensitivity to such object affordances may contribute to some symptoms of the disease. Employing a paradigm that measures the degree of interference from object affordances on voluntary actions, we confirm that activation of object affordances are preserved in Parkinson's disease, but find no evidence that there is an increased sensitivity to the effects of object affordances on voluntary action. PMID:19616073

  2. Zernike phase contrast cryo-electron tomography of sodium-driven flagellar hook-basal bodies from Vibrio alginolyticus.

    Science.gov (United States)

    Hosogi, Naoki; Shigematsu, Hideki; Terashima, Hiroyuki; Homma, Michio; Nagayama, Kuniaki

    2011-01-01

    Vibrio alginolyticus use flagella to swim. A flagellum consists of a filament, hook and basal body. The basal body is made up of a rod and several ring structures. This study investigates the structure of the T ring which is a unique component of the V. alginolyticus sodium ion-driven flagellar basal body. Using Zernike phase contrast (ZPC) cryo-electron tomography, we compared the 3D structures of purified hook-basal bodies (HBB) from a wild-type strain (KK148) and a deletion mutant lacking MotX and MotY (TH3), which are thought to form the T ring. ZPC images of HBBs had highly improved signal-to-noise ratio compared to conventional phase contrast images. We observed the outline of the HBBs from strains KK148 and TH3, and the TH3 mutant was missing its T ring. In the wild-type strain, the T ring was beneath the LP ring and seemed to form a ring shape with diameter of 32 nm. Copyright © 2010 Elsevier Inc. All rights reserved.

  3. CDKL5 regulates flagellar length and localizes to the base of the flagella in Chlamydomonas

    Science.gov (United States)

    Tam, Lai-Wa; Ranum, Paul T.; Lefebvre, Paul A.

    2013-01-01

    The length of Chlamydomonas flagella is tightly regulated. Mutations in four genes—LF1, LF2, LF3, and LF4—cause cells to assemble flagella up to three times wild-type length. LF2 and LF4 encode protein kinases. Here we describe a new gene, LF5, in which null mutations cause cells to assemble flagella of excess length. The LF5 gene encodes a protein kinase very similar in sequence to the protein kinase CDKL5. In humans, mutations in this kinase cause a severe form of juvenile epilepsy. The LF5 protein localizes to a unique location: the proximal 1 μm of the flagella. The proximal localization of the LF5 protein is lost when genes that make up the proteins in the cytoplasmic length regulatory complex (LRC)—LF1, LF2, and LF3—are mutated. In these mutants LF5p becomes localized either at the distal tip of the flagella or along the flagellar length, indicating that length regulation involves, at least in part, control of LF5p localization by the LRC. PMID:23283985

  4. Altered neuronal activity in the primary motor cortex and globus pallidus after dopamine depletion in rats.

    Science.gov (United States)

    Wang, Min; Li, Min; Geng, Xiwen; Song, Zhimin; Albers, H Elliott; Yang, Maoquan; Zhang, Xiao; Xie, Jinlu; Qu, Qingyang; He, Tingting

    2015-01-15

    The involvement of dopamine (DA) neuron loss in the etiology of Parkinson's disease has been well documented. The neural mechanisms underlying the effects of DA loss and the resultant motor dysfunction remain unknown. To gain insights into how loss of DA disrupts the electrical processes in the cortico-subcortical network, the present study explores the effects of DA neuron depletion on electrical activity in the primary motor cortex (M1), on the external and the internal segment of the globus pallidus (GPe and GPi respectively), and on their temporal relationships. Comparison of local field potentials (LFPs) in these brain regions from unilateral hemispheric DA neuron depleted rats and neurologically intact rats revealed that the spectrum power of LFPs in 12-70Hz (for M1, and GPe) and in 25-40Hz (for GPi) was significantly greater in the DA depleted rats than that in the control group. These changes were associated with a shortening of latency in LFP activities between M1 and GPe, from several hundred milliseconds in the intact animals to close to zero in the DA depleted animals. LFP oscillations in M1 were significantly more synchronized with those in GPe in the DA depleted rats compared with those in the control rats. By contrast, the synchronization of oscillation in LFP activities between M1 and GPi did not differ between the DA depleted and intact rats. Not surprisingly, rats that had DA neuron depletion spent more time along the ladder compared with the control rats. These data suggest that enhanced oscillatory activity and increased synchronization of LFPs may contribute to movement impairment in the rat model of Parkinson's disease. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Ipsilateral corticotectal projections from the primary, premotor and supplementary motor cortical areas in adult macaque monkeys: a quantitative anterograde tracing study

    Science.gov (United States)

    Fregosi, Michela; Rouiller, Eric M.

    2018-01-01

    The corticotectal projection from cortical motor areas is one of several descending pathways involved in the indirect control of spinal motoneurons. In non-human primates, previous studies reported that cortical projections to the superior colliculus originated from the premotor cortex and the primary motor cortex, whereas no projection originated from the supplementary motor area. The aim of the present study was to investigate and compare the properties of corticotectal projections originating from these three cortical motor areas in intact adult macaques (n=9). The anterograde tracer BDA was injected into one of these cortical areas in each animal. Individual axonal boutons, both en passant and terminaux, were charted and counted in the different layers of the ipsilateral superior colliculus. The data confirmed the presence of strong corticotectal projections from the premotor cortex. A new observation was that strong corticotectal projections were also found to originate from the supplementary motor area (its proper division). The corticotectal projection from the primary motor cortex was quantitatively less strong than that from either the premotor or supplementary motor areas. The corticotectal projection from each motor area was directed mainly to the deep layer of the superior colliculus, although its intermediate layer was also a consistent target of fairly dense terminations. The strong corticotectal projections from non-primary motor areas are in position to influence the preparation and planning of voluntary movements. PMID:28921678

  6. Xenopus egg cytoplasm with intact actin.

    Science.gov (United States)

    Field, Christine M; Nguyen, Phuong A; Ishihara, Keisuke; Groen, Aaron C; Mitchison, Timothy J

    2014-01-01

    We report optimized methods for preparing Xenopus egg extracts without cytochalasin D, that we term "actin-intact egg extract." These are undiluted egg cytoplasm that contains abundant organelles, and glycogen which supplies energy, and represents the least perturbed cell-free cytoplasm preparation we know of. We used this system to probe cell cycle regulation of actin and myosin-II dynamics (Field et al., 2011), and to reconstitute the large, interphase asters that organize early Xenopus embryos (Mitchison et al., 2012; Wühr, Tan, Parker, Detrich, & Mitchison, 2010). Actin-intact Xenopus egg extracts are useful for analysis of actin dynamics, and interaction of actin with other cytoplasmic systems, in a cell-free system that closely mimics egg physiology, and more generally for probing the biochemistry and biophysics of the egg, zygote, and early embryo. Detailed protocols are provided along with assays used to check cell cycle state and tips for handling and storing undiluted egg extracts. © 2014 Elsevier Inc. All rights reserved.

  7. Effect of motor limitations on the expression of aggressiveness among adolescents.

    Science.gov (United States)

    Tripković, Mara; Matijević, Valentina; Marković, Hrvoje; Ercegovi, Nela

    2015-03-01

    This study examined how motor limitations in terms of reduced possibilities to move influence aggression, starting from the fact that motor skills and movement have an important place in the expression of aggression, as well as the tendency of adolescents to "body language". Adolescent with motor deficit is hindered in gaining experience of one's own body, which is reflected in the formation of complete experience of himself, or constitution of the self. In many of the functions of motor skills and movement aggression has a significant place that we wanted to determine without deeper analysis of whether the origin of aggression is instinctive or it is always just the result of frustration. The sample on which testing was performed consisted of 100 randomly selected subjects of both genders aged 16-18 years. Fifty subjects had motor limitations due to illness or injury, and another fifty subjects had intact motor functions. The study used three instruments: 1) A-87 questionnaire for aggressiveness examination; 2) structured interview; and 3) protocol for observation under natural conditions. Results of the analysis of data obtained in total score, as well as in all five subscales of the A-87 questionnaire for aggressiveness examination showed that the two groups were not significantly different. The results obtained by structured interview showed the adolescents with motor limitations to demonstrate greater verbal aggressiveness, then latent physical aggressiveness. A statistically significant between-group difference was obtained on the factor of self-destructiveness, which implies that adolescents with motor limitations are somewhat more self-destructive compared to those in control group. From the results obtained by the protocol for systematic observation in natural conditions, it was evident that there were significant differences on most of perceptual conducts between control and experimental group, whereby adolescents with motor limitations were more

  8. Bimanual coupling paradigm as an effective tool to investigate productive behaviors in motor and body awareness impairments.

    Science.gov (United States)

    Garbarini, Francesca; Pia, Lorenzo

    2013-11-05

    When humans move simultaneously both hands strong coupling effects arise and neither of the two hands is able to perform independent actions. It has been suggested that such motor constraints are tightly linked to action representation rather than to movement execution. Hence, bimanual tasks can represent an ideal experimental tool to investigate internal motor representations in those neurological conditions in which the movement of one hand is impaired. Indeed, any effect on the "moving" (healthy) hand would be caused by the constraints imposed by the ongoing motor program of the 'impaired' hand. Here, we review recent studies that successfully utilized the above-mentioned paradigms to investigate some types of productive motor behaviors in stroke patients. Specifically, bimanual tasks have been employed in left hemiplegic patients who report illusory movements of their contralesional limbs (anosognosia for hemiplegia). They have also been administered to patients affected by a specific monothematic delusion of body ownership, namely the belief that another person's arm and his/her voluntary action belong to them. In summary, the reviewed studies show that bimanual tasks are a simple and valuable experimental method apt to reveal information about the motor programs of a paralyzed limb. Therefore, it can be used to objectively examine the cognitive processes underpinning motor programming in patients with different delusions of motor behavior. Additionally, it also sheds light on the mechanisms subserving bimanual coordination in the intact brain suggesting that action representation might be sufficient to produce these effects.

  9. Unique ATPase site architecture triggers cis-mediated synchronized ATP binding in heptameric AAA+-ATPase domain of flagellar regulatory protein FlrC.

    Science.gov (United States)

    Dey, Sanjay; Biswas, Maitree; Sen, Udayaditya; Dasgupta, Jhimli

    2015-04-03

    Bacterial enhancer-binding proteins (bEBPs) oligomerize through AAA(+) domains and use ATP hydrolysis-driven energy to isomerize the RNA polymerase-σ(54) complex during transcriptional initiation. Here, we describe the first structure of the central AAA(+) domain of the flagellar regulatory protein FlrC (FlrC(C)), a bEBP that controls flagellar synthesis in Vibrio cholerae. Our results showed that FlrC(C) forms heptamer both in nucleotide (Nt)-free and -bound states without ATP-dependent subunit remodeling. Unlike the bEBPs such as NtrC1 or PspF, a novel cis-mediated "all or none" ATP binding occurs in the heptameric FlrC(C), because constriction at the ATPase site, caused by loop L3 and helix α7, restricts the proximity of the trans-protomer required for Nt binding. A unique "closed to open" movement of Walker A, assisted by trans-acting "Glu switch" Glu-286, facilitates ATP binding and hydrolysis. Fluorescence quenching and ATPase assays on FlrC(C) and mutants revealed that although Arg-349 of sensor II, positioned by trans-acting Glu-286 and Tyr-290, acts as a key residue to bind and hydrolyze ATP, Arg-319 of α7 anchors ribose and controls the rate of ATP hydrolysis by retarding the expulsion of ADP. Heptameric state of FlrC(C) is restored in solution even with the transition state mimicking ADP·AlF3. Structural results and pulldown assays indicated that L3 renders an in-built geometry to L1 and L2 causing σ(54)-FlrC(C) interaction independent of Nt binding. Collectively, our results underscore a novel mechanism of ATP binding and σ(54) interaction that strives to understand the transcriptional mechanism of the bEBPs, which probably interact directly with the RNA polymerase-σ(54) complex without DNA looping. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Split-phase motor running as capacitor starts motor and as capacitor run motor

    Directory of Open Access Journals (Sweden)

    Yahaya Asizehi ENESI

    2016-07-01

    Full Text Available In this paper, the input parameters of a single phase split-phase induction motor is taken to investigate and to study the output performance characteristics of capacitor start and capacitor run induction motor. The value of these input parameters are used in the design characteristics of capacitor run and capacitor start motor with each motor connected to rated or standard capacitor in series with auxiliary winding or starting winding respectively for the normal operational condition. The magnitude of capacitor that will develop maximum torque in capacitor start motor and capacitor run motor are investigated and determined by simulation. Each of these capacitors is connected to the auxiliary winding of split-phase motor thereby transforming it into capacitor start or capacitor run motor. The starting current and starting torque of the split-phase motor (SPM, capacitor run motor (CRM and capacitor star motor (CSM are compared for their suitability in their operational performance and applications.

  11. Assessment of geomechanical properties of intact Opalinus Clay - Expert report

    International Nuclear Information System (INIS)

    Amann, F.; Vogelhuber, M.

    2015-11-01

    This comprehensive report published by the Swiss Federal Nuclear Safety Inspectorate ENSI presents an expert report published on the assessment of the geomechanical properties of intact Opalinus Clay. This review report addresses the conceptual constitutive framework for repositories in Opalinus Clay. The author addresses the geomechanical fundamentals that are necessary in order to adequately judge experiments on intact Opalinus Clay and the interpretation of the results. The report assesses in detail the various test series on intact Opalinus Clay carried out along with the interpretations made by experts and NAGRA. Further assessments are quoted including those on sample geometries tested, effective strength properties, undrained shear strength properties and elastic properties. The results of work done by other experts are also presented and discussed. The report is completed with a list of relevant literature

  12. Assessment of geomechanical properties of intact Opalinus Clay - Expert report

    Energy Technology Data Exchange (ETDEWEB)

    Amann, F. [Eidgenössische Technische Hochschule ETHZ, Zürich (Switzerland); Vogelhuber, M. [Dr. von Moos AG, Geotechnisches Büro, Zürich (Switzerland)

    2015-11-15

    This comprehensive report published by the Swiss Federal Nuclear Safety Inspectorate ENSI presents an expert report published on the assessment of the geomechanical properties of intact Opalinus Clay. This review report addresses the conceptual constitutive framework for repositories in Opalinus Clay. The author addresses the geomechanical fundamentals that are necessary in order to adequately judge experiments on intact Opalinus Clay and the interpretation of the results. The report assesses in detail the various test series on intact Opalinus Clay carried out along with the interpretations made by experts and NAGRA. Further assessments are quoted including those on sample geometries tested, effective strength properties, undrained shear strength properties and elastic properties. The results of work done by other experts are also presented and discussed. The report is completed with a list of relevant literature.

  13. Motor control for a brushless DC motor

    Science.gov (United States)

    Peterson, William J. (Inventor); Faulkner, Dennis T. (Inventor)

    1985-01-01

    This invention relates to a motor control system for a brushless DC motor having an inverter responsively coupled to the motor control system and in power transmitting relationship to the motor. The motor control system includes a motor rotor speed detecting unit that provides a pulsed waveform signal proportional to rotor speed. This pulsed waveform signal is delivered to the inverter to thereby cause an inverter fundamental current waveform output to the motor to be switched at a rate proportional to said rotor speed. In addition, the fundamental current waveform is also pulse width modulated at a rate proportional to the rotor speed. A fundamental current waveform phase advance circuit is controllingly coupled to the inverter. The phase advance circuit is coupled to receive the pulsed waveform signal from the motor rotor speed detecting unit and phase advance the pulsed waveform signal as a predetermined function of motor speed to thereby cause the fundamental current waveform to be advanced and thereby compensate for fundamental current waveform lag due to motor winding reactance which allows the motor to operate at higher speeds than the motor is rated while providing optimal torque and therefore increased efficiency.

  14. The Function and Organization of the Motor System Controlling Flight Maneuvers in Flies.

    Science.gov (United States)

    Lindsay, Theodore; Sustar, Anne; Dickinson, Michael

    2017-02-06

    Animals face the daunting task of controlling their limbs using a small set of highly constrained actuators. This problem is particularly demanding for insects such as Drosophila, which must adjust wing motion for both quick voluntary maneuvers and slow compensatory reflexes using only a dozen pairs of muscles. To identify strategies by which animals execute precise actions using sparse motor networks, we imaged the activity of a complete ensemble of wing control muscles in intact, flying flies. Our experiments uncovered a remarkably efficient logic in which each of the four skeletal elements at the base of the wing are equipped with both large phasically active muscles capable of executing large changes and smaller tonically active muscles specialized for continuous fine-scaled adjustments. Based on the responses to a broad panel of visual motion stimuli, we have developed a model by which the motor array regulates aerodynamically functional features of wing motion. VIDEO ABSTRACT. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Swimming Motility Mediates the Formation of Neutrophil Extracellular Traps Induced by Flagellated Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Madison Floyd

    2016-11-01

    Full Text Available Pseudomonas aeruginosa is an opportunistic pathogen causing severe infections often characterized by robust neutrophilic infiltration. Neutrophils provide the first line of defense against P. aeruginosa. Aside from their defense conferred by phagocytic activity, neutrophils also release neutrophil extracellular traps (NETs to immobilize bacteria. Although NET formation is an important antimicrobial process, the details of its mechanism are largely unknown. The identity of the main components of P. aeruginosa responsible for triggering NET formation is unclear. In this study, our focus was to identify the main bacterial factors mediating NET formation and to gain insight into the underlying mechanism. We found that P. aeruginosa in its exponential growth phase promoted strong NET formation in human neutrophils while its NET-inducing ability dramatically decreased at later stages of bacterial growth. We identified the flagellum as the primary component of P. aeruginosa responsible for inducing NET extrusion as flagellum-deficient bacteria remained seriously impaired in triggering NET formation. Purified P. aeruginosa flagellin, the monomeric component of the flagellum, does not stimulate NET formation in human neutrophils. P. aeruginosa-induced NET formation is independent of the flagellum-sensing receptors TLR5 and NLRC4 in both human and mouse neutrophils. Interestingly, we found that flagellar motility, not flagellum binding to neutrophils per se, mediates NET release induced by flagellated bacteria. Immotile, flagellar motor-deficient bacterial strains producing paralyzed flagella did not induce NET formation. Forced contact between immotile P. aeruginosa and neutrophils restored their NET-inducing ability. Both the motAB and motCD genetic loci encoding flagellar motor genes contribute to maximal NET release; however the motCD genes play a more important role. Phagocytosis of P. aeruginosa and superoxide production by neutrophils were also

  16. Self-etching adhesive on intact enamel, with and without pre-etching.

    Science.gov (United States)

    Devarasa, G M; Subba Reddy, V V; Chaitra, N L; Swarna, Y M

    2012-05-01

    Bond strengths of composite resin to enamel using self-etch adhesive (SEA) Clearfil SE bond system on intact enamel and enamel pre-etched with phosphoric acid were compared. The objective was to determine if the pre-etching would increase the bond strengths of the SEA systems to intact enamel and to evaluate the effect of pre-etching on bond formation of self-etch adhesives on intact enamel. Labial surfaces of 40 caries free permanent upper central and lateral incisors were cleaned, sectioned of their roots. All specimens were mounted on acrylic block and divided randomly into four groups. In two groups the application of self-etch adhesive, Clearfil SE bond was carried as per manufacturer's instructions, composite cylinders were built, whereas in the other two groups, 37% phosphoric acid etching was done before the application of self-etching adhesives. Then the resin tags were analyzed using scanning electron microscope and shear bond strength was measured using Instron universal testing machine. When phosphoric acid was used, there was significant increase in the depth of penetration of resin tags and in the Shear Bond Strength of composite to enamel. The results indicate that out of both treatment groups, pre-etching the intact enamel with 37% phosphoric acid resulted in formation of longer resin tags and higher depth of penetration of resin tags of the Clearfil SE bond, and attaining higher bond strength of the Clearfil SE bond to intact enamel. Copyright © 2011 Wiley Periodicals, Inc.

  17. Intact mirror mechanisms for automatic facial emotions in children and adolescents with autism spectrum disorder.

    Science.gov (United States)

    Schulte-Rüther, Martin; Otte, Ellen; Adigüzel, Kübra; Firk, Christine; Herpertz-Dahlmann, Beate; Koch, Iring; Konrad, Kerstin

    2017-02-01

    It has been suggested that an early deficit in the human mirror neuron system (MNS) is an important feature of autism. Recent findings related to simple hand and finger movements do not support a general dysfunction of the MNS in autism. Studies investigating facial actions (e.g., emotional expressions) have been more consistent, however, mostly relied on passive observation tasks. We used a new variant of a compatibility task for the assessment of automatic facial mimicry responses that allowed for simultaneous control of attention to facial stimuli. We used facial electromyography in 18 children and adolescents with Autism spectrum disorder (ASD) and 18 typically developing controls (TDCs). We observed a robust compatibility effect in ASD, that is, the execution of a facial expression was facilitated if a congruent facial expression was observed. Time course analysis of RT distributions and comparison to a classic compatibility task (symbolic Simon task) revealed that the facial compatibility effect appeared early and increased with time, suggesting fast and sustained activation of motor codes during observation of facial expressions. We observed a negative correlation of the compatibility effect with age across participants and in ASD, and a positive correlation between self-rated empathy and congruency for smiling faces in TDC but not in ASD. This pattern of results suggests that basic motor mimicry is intact in ASD, but is not associated with complex social cognitive abilities such as emotion understanding and empathy. Autism Res 2017, 10: 298-310. © 2016 International Society for Autism Research, Wiley Periodicals, Inc. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

  18. Bimanual coupling paradigm as an effective tool to investigate productive behaviors in motor and body awareness impairments

    Directory of Open Access Journals (Sweden)

    Francesca eGarbarini

    2013-11-01

    Full Text Available When humans move simultaneously both hands strong coupling effects arise and neither of the two hands is able to perform independent actions. It has been suggested that such motor constraints are tightly linked to action representation rather than to movement execution. Hence, bimanual tasks can represent an ideal experimental tool to investigate internal motor representations in those neurological conditions in which the movement of one hand is impaired. Indeed, any effect on the ‘moving’ (healthy hand would be caused by the constraints imposed by the ongoing motor program of the ‘impaired’ hand. Here, we review recent studies that successfully utilized the above-mentioned paradigms to investigate some types of productive motor behaviors in stroke patients. Specifically, bimanual tasks have been employed in left hemiplegic patients who report illusory movements of their contralesional limbs (anosognosia for hemiplegia. They have also been administered to patients affected by a specific monothematic delusion of body ownership, namely the belief that another person’s arm and his/her voluntary action belong to them. In summary, the reviewed studies show that bimanual tasks are a simple and valuable experimental method apt to reveal information about the motor programs of a paralyzed limb. Therefore, it can be used to objectively examine the cognitive processes underpinning motor programming in patients with different delusions of motor behavior. Additionally, it also sheds light on the mechanisms subserving bimanual coordination in the intact brain suggesting that action representation might be sufficient to produce these effects.

  19. The Multilevel Mixed Intact Group Analysis: A Mixed Method to Seek, Detect, Describe and Explain Differences Between Intact Groups

    NARCIS (Netherlands)

    Schoonenboom, J.I.

    2014-01-01

    Educational innovations often involve intact subgroups, such as school classes or university departments. In small-scale educational evaluation research, typically involving 1 to 20 subgroups, differences among these subgroups are often neglected. This article presents a mixed method from a

  20. Difficulties with Fine Motor Skills and Cognitive Impairment in an Elderly Population: The Progetto Veneto Anziani.

    Science.gov (United States)

    Curreri, Chiara; Trevisan, Caterina; Carrer, Pamela; Facchini, Silvia; Giantin, Valter; Maggi, Stefania; Noale, Marianna; De Rui, Marina; Perissinotto, Egle; Zambon, Sabina; Crepaldi, Gaetano; Manzato, Enzo; Sergi, Giuseppe

    2018-02-01

    To investigate dysfunction in fine motor skills in a cohort of older Italian adults, identifying their prevalence and usefulness as indicators and predictors of cognitive impairment. Population-based longitudinal study with mean follow-up of 4.4 years. Community. Older men and women enrolled in the Progetto Veneto Anziani (Pro.V.A.) (N = 2,361); 1,243 subjects who were cognitively intact at baseline were selected for longitudinal analyses. Fine motor skills were assessed by measuring the time needed to successfully complete two functional tasks: putting on a shirt and a manual dexterity task. Cognitive impairment was defined as a Mini-Mental State Examination (MMSE) score less than 24. On simple correlation, baseline MMSE score was significantly associated with the manual dexterity task (correlation coefficient (r) = -0.25, P motor tasks were significantly associated with changes in MMSE (putting on a shirt: β = 0.083, P = .003; manual dexterity task: β = 0.098, P motor skills are common in older adults, and assessing them may help to identify early signs of dementia, subjects at high risk to develop cognitive decline, and individuals who can be referred to specialists. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

  1. Comparison of Athletics Records of Intellectually Disabled Persons with Records of Intact Athletes

    Directory of Open Access Journals (Sweden)

    Pavel Tilinger

    2014-07-01

    Full Text Available Comparison of Athletics Records of Intellectually Disabled Persons with Records of Intact Athletes Comparative studies between intact and ID (Intellectually Disabled individuals have been carried out in many areas (psychic, somatic characteristics, motor skills of individuals with ID, comparison of the level of intellect and motor performance. The study compares the records of intellectually disabled athletes with the records of majority population athletes. For comparison, we have used the existing world records registered by the International Association of Athletics Federations (IAAF, and Inas, (International Sports Federation for Persons with Intellectual Disability. To compare the best Czech records with world records, the best performances of women registered by the ČSMPS (Czech Sports Association for the Mentally Handicapped were used. If we compare the World Records (IAAF and Inas, we can find differences ranging from 8.2 to 45.3%. The differences between intact and intellectually disabled men are approx. by 2 to 10% lower than in women’s similar events. It is only in three events that the differences between intact and ID are slightly lower in women than in men (high jump, discus throw, javelin throw. The smallest differences between the IAAF and Inas records are in sprints events and middle running distances of men and women (10% men, or 15% women respectively. The differences in long distances reach 18% (men and 23% (women. The differences in jumping events are very different, accounting for 20% for men and 24% for women with some generalization. Throwing events for practically both sexes bring differences above 40% (except for shot put. Srovnání atletických rekordů intelektově postižených osob s rekordy intaktních sportovců Srovnávací studie mezi IP a intaktními byly realizovány v řadě oblastí (psychika, somatické charakteristiky, motorika jedinců s IP, srovnání úrovně intelektu a motorické v

  2. High efficiency motors; Motores de alta eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Uranga Favela, Ivan Jaime [Energia Controlada de Mexico, S. A. de C. V., Mexico, D. F. (Mexico)

    1993-12-31

    This paper is a technical-financial study of the high efficiency and super-premium motors. As it is widely known, more than 60% of the electrical energy generated in the country is used for the operation of motors, in industry as well as in commerce. Therefore the importance that the motors have in the efficient energy use. [Espanol] El presente trabajo es un estudio tecnico-financiero de los motores de alta eficiencia y los motores super premium. Como es ampliamente conocido, mas del 60% de la energia electrica generada en el pais, es utilizada para accionar motores, dentro de la industria y el comercio. De alli la importancia que los motores tienen en el uso eficiente de la energia.

  3. High efficiency motors; Motores de alta eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Uranga Favela, Ivan Jaime [Energia Controlada de Mexico, S. A. de C. V., Mexico, D. F. (Mexico)

    1992-12-31

    This paper is a technical-financial study of the high efficiency and super-premium motors. As it is widely known, more than 60% of the electrical energy generated in the country is used for the operation of motors, in industry as well as in commerce. Therefore the importance that the motors have in the efficient energy use. [Espanol] El presente trabajo es un estudio tecnico-financiero de los motores de alta eficiencia y los motores super premium. Como es ampliamente conocido, mas del 60% de la energia electrica generada en el pais, es utilizada para accionar motores, dentro de la industria y el comercio. De alli la importancia que los motores tienen en el uso eficiente de la energia.

  4. Threats to intact tropical peatlands and opportunities for their conservation.

    Science.gov (United States)

    Roucoux, K H; Lawson, I T; Baker, T R; Del Castillo Torres, D; Draper, F C; Lähteenoja, O; Gilmore, M P; Honorio Coronado, E N; Kelly, T J; Mitchard, E T A; Vriesendorp, C F

    2017-12-01

    Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza-Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land-use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon-dense (domed pole forest) areas. New carbon-based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development. © 2017 The Authors. Conservation Biology published by Wiley Periodicals, Inc

  5. Epispadias in boys with an intact prepuce

    NARCIS (Netherlands)

    Bos, E. M. E.; Kuijper, C. F.; Chrzan, R. J.; Dik, P.; Klijn, A. J.; de Jong, T. P. V. M.

    2014-01-01

    To present an overview of the clinical presentation and pathological anatomy, and the results of surgical correction of 7 cases of epispadias with intact prepuce; a rare condition that has only occasionally been reported in literature. A retrospective search was performed in the surgical and

  6. HYDROCARBON VAPOR DIFFUSION IN INTACT CORE SLEEVES

    Science.gov (United States)

    The diffusion of 2,2,4-trimethylpentane (TMP) and 2,2,5-trimethylhexane (TMH) vapors put of residually contaminated sandy soil from the U.S. Environmental Protection Agency (EPA) field research site at Traverse City, Michigan, was measured and modeled. The headspace of an intact ...

  7. Digested BLG can induce tolerance when co-administered with intact BLG in Brown Norway rats

    DEFF Research Database (Denmark)

    Bøgh, Katrine Lindholm; Barkholt, Vibeke; Madsen, Charlotte Bernhard

    the human gastro-duodenal digestion process. Four different fractions of BLG-digest was made, based on sizes of peptides or aggregates hereof. Intact BLG and the four fractions of BLG-digesta were characterized by protein chemical analyses. Brown Norway (BN) rats were immunised i.p. three times without......Background: Milk is a major constituent of small children’s diet. Milk allergy is also one of the most common allergies in small children. Prevention, treatment and general understanding of this allergy are therefore important. Methods: Intact BLG was digested in an in vitro model simulating...... the use of adjuvant with either PBS (control), 200 µg of intact BLG, 30 µg of intact BLG, 200 µg of digested BLG (with 30 µg of intact BLG), 200 µg of digested BLG, 200 µg of a fraction of large complexes or 200 µg of a fraction of small complexes (all three without intact BLG). Sera from BN rats were...

  8. Impact of fluorescent protein fusions on the bacterial flagellar motor

    NARCIS (Netherlands)

    Heo, M.; Nord, A. L.; Chamousset, D.; van Rijn, E.; Beaumont, H.J.E.; Pedaci, F.

    2017-01-01

    Fluorescent fusion proteins open a direct and unique window onto protein function. However, they also introduce the risk of perturbation of the function of the native protein. Successful applications of fluorescent fusions therefore rely on a careful assessment and minimization of the side

  9. Intacting Integrity in coping with health issues

    DEFF Research Database (Denmark)

    Jepsen, Stine Leegaard; Bastrup Jørgensen, Lene; Fridlund, Bengt

    2017-01-01

    The aim of this study was to develop a formal substantive theory (FST) on the multidimensional behavioral process of coping with health issues. Intacting integrity while coping with health issues emerged as the core category of this FST. People facing health issues strive to safeguard and keep...

  10. Visual speech alters the discrimination and identification of non-intact auditory speech in children with hearing loss.

    Science.gov (United States)

    Jerger, Susan; Damian, Markus F; McAlpine, Rachel P; Abdi, Hervé

    2017-03-01

    Understanding spoken language is an audiovisual event that depends critically on the ability to discriminate and identify phonemes yet we have little evidence about the role of early auditory experience and visual speech on the development of these fundamental perceptual skills. Objectives of this research were to determine 1) how visual speech influences phoneme discrimination and identification; 2) whether visual speech influences these two processes in a like manner, such that discrimination predicts identification; and 3) how the degree of hearing loss affects this relationship. Such evidence is crucial for developing effective intervention strategies to mitigate the effects of hearing loss on language development. Participants were 58 children with early-onset sensorineural hearing loss (CHL, 53% girls, M = 9;4 yrs) and 58 children with normal hearing (CNH, 53% girls, M = 9;4 yrs). Test items were consonant-vowel (CV) syllables and nonwords with intact visual speech coupled to non-intact auditory speech (excised onsets) as, for example, an intact consonant/rhyme in the visual track (Baa or Baz) coupled to non-intact onset/rhyme in the auditory track (/-B/aa or/-B/az). The items started with an easy-to-speechread/B/or difficult-to-speechread/G/onset and were presented in the auditory (static face) vs. audiovisual (dynamic face) modes. We assessed discrimination for intact vs. non-intact different pairs (e.g., Baa:/-B/aa). We predicted that visual speech would cause the non-intact onset to be perceived as intact and would therefore generate more same-as opposed to different-responses in the audiovisual than auditory mode. We assessed identification by repetition of nonwords with non-intact onsets (e.g.,/-B/az). We predicted that visual speech would cause the non-intact onset to be perceived as intact and would therefore generate more Baz-as opposed to az- responses in the audiovisual than auditory mode. Performance in the audiovisual mode showed more same

  11. Visual Speech Alters the Discrimination and Identification of Non-Intact Auditory Speech in Children with Hearing Loss

    Science.gov (United States)

    Jerger, Susan; Damian, Markus F.; McAlpine, Rachel P.; Abdi, Hervé

    2017-01-01

    Objectives Understanding spoken language is an audiovisual event that depends critically on the ability to discriminate and identify phonemes yet we have little evidence about the role of early auditory experience and visual speech on the development of these fundamental perceptual skills. Objectives of this research were to determine 1) how visual speech influences phoneme discrimination and identification; 2) whether visual speech influences these two processes in a like manner, such that discrimination predicts identification; and 3) how the degree of hearing loss affects this relationship. Such evidence is crucial for developing effective intervention strategies to mitigate the effects of hearing loss on language development. Methods Participants were 58 children with early-onset sensorineural hearing loss (CHL, 53% girls, M = 9;4 yrs) and 58 children with normal hearing (CNH, 53% girls, M = 9;4 yrs). Test items were consonant-vowel (CV) syllables and nonwords with intact visual speech coupled to non-intact auditory speech (excised onsets) as, for example, an intact consonant/rhyme in the visual track (Baa or Baz) coupled to non-intact onset/rhyme in the auditory track (/–B/aa or /–B/az). The items started with an easy-to-speechread /B/ or difficult-to-speechread /G/ onset and were presented in the auditory (static face) vs. audiovisual (dynamic face) modes. We assessed discrimination for intact vs. non-intact different pairs (e.g., Baa:/–B/aa). We predicted that visual speech would cause the non-intact onset to be perceived as intact and would therefore generate more same—as opposed to different—responses in the audiovisual than auditory mode. We assessed identification by repetition of nonwords with non-intact onsets (e.g., /–B/az). We predicted that visual speech would cause the non-intact onset to be perceived as intact and would therefore generate more Baz—as opposed to az— responses in the audiovisual than auditory mode. Results

  12. Performance of intact and castrated beef cattle in an intensive croppasture rotation system

    Directory of Open Access Journals (Sweden)

    Tercilio Turini

    2015-07-01

    Full Text Available This research had as objective to evaluate the performance of intact or castrated beef cattle in a croppasture rotation system. The experiment was conducted during 2004 and 2005, and carried out at the Cooperativa Agropecuária Mourãoense (COAMO Experimental Farm, in Campo Mourão city, Paraná state. It was used a completely randomized design, with two treatments, intact or castrated. Forty ½Angus+½Nelore crossbred animals, with average age of nine months, were used. Half of the animals were castrated at weaning, and the other half was kept intact. Pasture was composed of two areas. The winter field, established after soybean crop, was composed by a mixture of black oat (Avena strigosa and Italian ryegrass (Lolium multiforum. The summer field was composed by stargrass (Cynodon nlemfuensis and Mombaça grass (Panicum maximum. During the winter time it was used a continues grazing system, with regulator animals (put and take, and during the summer an intensive rotational system, with regulator animals and fixed grazing period. Intact animals presented higher average daily weight gain (0.907 vs 0.698 kg, slaughter weight (490.9 vs 442.2 kg, and hot carcass weight (250.2 vs 232.6 kg. Slaughter age was influenced by sexual condition, being lesser in the intact animals. Carcass dressing percentage was similar for the groups. Castrated animals showed better finishing fat cover and backfat thickness (3.45 vs 2.70 mm compared to intact ones. Therefore, it can be concluded that intact animals presents better performance than castrated ones when finished in an intensive crop-pasture rotation system, however, they may not present the minimum required fat cover, when slaughter at young ages.

  13. To What Extent Can Motor Imagery Replace Motor Execution While Learning a Fine Motor Skill?

    NARCIS (Netherlands)

    Sobierajewicz, Jagna; Szarkiewicz, Sylwia; Prekoracka-Krawczyk, Anna; Jaskowski, Wojciech; van der Lubbe, Robert Henricus Johannes

    2016-01-01

    Motor imagery is generally thought to share common mechanisms with motor execution. In the present study, we examined to what extent learning a fine motor skill by motor imagery may substitute physical practice. Learning effects were assessed by manipulating the proportion of motor execution and

  14. Cholesteatoma behind an intact tympanic membrane: histopathologic evidence for a tympanic membrane origin.

    Science.gov (United States)

    Sudhoff, H; Linthicum, F H

    2001-07-01

    Several theories have been proposed with respect to the origin and pathogenesis of cholesteatoma behind an intact tympanic membrane. The authors describe a case of cholesteatoma behind an intact tympanic membrane in a 71-year-old man with a history of tympanic membrane retraction fixed to the incus without evidence of a perforation. The membrane eventually became detached, and remnants of keratinizing squamous epithelium were found on the incus. Mechanisms such as metaplasia, ectopic epidermis rests, or ingrowth of meatal epidermis have been proposed to explain the pathogenesis of cholesteatoma behind an intact tympanic membrane. These findings, based on temporal bone histopathology, support the role of an acquired epidermal rest. This case report provides evidence that cholesteatoma behind an intact tympanic membrane can be established from a resolved retraction of the pars tensa of the tympanic membrane.

  15. The Multilevel Mixed Intact Group Analysis: A Mixed Method to Seek, Detect, Describe, and Explain Differences Among Intact Groups

    Science.gov (United States)

    Schoonenboom, Judith

    2016-01-01

    Educational innovations often involve intact subgroups, such as school classes or university departments. In small-scale educational evaluation research, typically involving 1 to 20 subgroups, differences among these subgroups are often neglected. This article presents a mixed method from a qualitative perspective, in which differences among…

  16. Structural determination of intact proteins using mass spectrometry

    Science.gov (United States)

    Kruppa, Gary [San Francisco, CA; Schoeniger, Joseph S [Oakland, CA; Young, Malin M [Livermore, CA

    2008-05-06

    The present invention relates to novel methods of determining the sequence and structure of proteins. Specifically, the present invention allows for the analysis of intact proteins within a mass spectrometer. Therefore, preparatory separations need not be performed prior to introducing a protein sample into the mass spectrometer. Also disclosed herein are new instrumental developments for enhancing the signal from the desired modified proteins, methods for producing controlled protein fragments in the mass spectrometer, eliminating complex microseparations, and protein preparatory chemical steps necessary for cross-linking based protein structure determination.Additionally, the preferred method of the present invention involves the determination of protein structures utilizing a top-down analysis of protein structures to search for covalent modifications. In the preferred method, intact proteins are ionized and fragmented within the mass spectrometer.

  17. Fear of movement modulates the feedforward motor control of the affected limb in complex regional pain syndrome (CRPS): A single-case study.

    Science.gov (United States)

    Osumi, Michihiro; Sumitani, Masahiko; Otake, Yuko; Morioka, Shu

    2018-01-01

    Pain-related fear can exacerbate physical disability and pathological pain in complex regional pain syndrome (CRPS) patients. We conducted a kinematic analysis of grasping movements with a pediatric patient suffering from CRPS in an upper limb to investigate how pain-related fear affects motor control. Using a three-dimensional measurement system, we recorded the patient's movement while grasping three vertical bars of different diameters (thin, middle, thick) with the affected and intact hands. We analyzed the maximum grasp distance between the thumb and the index finger (MGD), the peak velocity of the grasp movement (PV), and the time required for the finger opening phase (TOP) and closing phase (TCP). Consequently, the MGD and PV of grasp movements in the affected hand were significantly smaller than those of the intact hand when grasping the middle and thick bars. This might reflect pain-related fear against visual information of the target size which evokes sensation of difficulty in opening fingers widely to grasp the middle and thick bars. Although MGD and PV increased with target size, the TOP was longer in the affected hand when grasping the thick bar. These findings indicate that pain-related fear impairs motor commands that are sent to the musculoskeletal system, subsequently disrupting executed movements and their sensory feedback. Using kinematic analysis, we objectively demonstrated that pain-related fear affects the process of sending motor commands towards the musculoskeletal system in the CRPS-affected hand, providing a possible explanatory model of pathological pain. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Development of uncoupling between D1- and D2-mediated motor behavior in rats depleted of dopamine as neonates.

    Science.gov (United States)

    Byrnes, E M; Bruno, J P

    1994-09-01

    The D1- and D2-mediation of stimulated motor behavior was studied in pups (Days 10-11) and weanlings (Days 20-21) that had been depleted of dopamine (DA) on postnatal Day 3. Administration of the D1-like agonist SKF 38393 (30.0 mg/kg) or the D2-like agonist quinpirole (3.0 mg/kg) increased the incidence of sniffing and locomotion in intact and DA-depleted animals tested at either age. However, the ability of selective DA antagonists to reduce these stimulated responses interacted with both the depletion and the age at the time of testing. When tested as pups, both the D1 antagonist SCH 23390 (0.2 or 0.4 mg/kg) and the D2 antagonist clebopride (10.0 mg/kg) suppressed the behaviors induced by either class of DA agonist. When tested as weanlings, intact animals exhibited the profile of pups (i.e., either antagonist blocked each agonist). In DA-depleted weanlings, however, only the D1 antagonist blocked the D1 agonist-induced responses and only the D2 antagonist blocked the D2 agonist-induced responses. These data demonstrate that the interactions between D1 and D2 receptors in the expression of stimulated motor behaviors are altered following DA depletions in neonates. Moreover, this change in receptor function occurs sometime between 7 and 13 days after the DA depletion.

  19. How can we conserve intact tropical peatlands?

    Science.gov (United States)

    Lawson, Ian; Roucoux, Katherine

    2017-04-01

    The scientific community has, for more than three decades, been expressing increasing alarm about the fate of peatlands in parts of Indonesia and Malaysia, where extensive land-use conversion and drainage for rice and oil palm have greatly compromised peatland hydrology, ecology, biological richness, and carbon storage. The discourse in the literature on these peatlands is now moving on from attempts to preserve the last remaining fragments of peat-swamp forest, towards discussion of how best to restore damaged ecosystems, and whether it is possible to manage plantations more 'sustainably'. It is becoming increasingly clear, however, that peatlands occur quite widely in other parts of the lowland tropics, including parts of Amazonia and the Congo Basin, and many of these peatlands can reasonably be described as 'intact': although few if any parts of the tropics are totally unaffected by human actions, the hydrology and functional ecology of these systems appear to be close to a 'natural' state. The question then arises as to what should be done with the knowledge of their existence. Here we analyse the arguments in favour of protecting intact peatlands, and the potential conflicts with other priorities such as economic development and social justice. We evaluate alternative mechanisms for protecting intact peatlands, focusing on the particular issues raised by peatlands as opposed to other kinds of tropical ecosystem. We identify ways in which natural science agendas can help to inform these arguments, using our own contributions in palaeoecology and carbon mapping as examples. Finally, we argue for a radical reconsideration of research agendas in tropical peatlands, highlighting the potential contribution of methodologies borrowed from the social sciences and humanities.

  20. Specific Deficit in Implicit Motor Sequence Learning following Spinal Cord Injury.

    Directory of Open Access Journals (Sweden)

    Ayala Bloch

    Full Text Available Physical and psychosocial rehabilitation following spinal cord injury (SCI leans heavily on learning and practicing new skills. However, despite research relating motor sequence learning to spinal cord activity and clinical observations of impeded skill-learning after SCI, implicit procedural learning following spinal cord damage has not been examined.To test the hypothesis that spinal cord injury (SCI in the absence of concomitant brain injury is associated with a specific implicit motor sequence learning deficit that cannot be explained by depression or impairments in other cognitive measures.Ten participants with SCI in T1-T11, unharmed upper limb motor and sensory functioning, and no concomitant brain injury were compared to ten matched control participants on measures derived from the serial reaction time (SRT task, which was used to assess implicit motor sequence learning. Explicit generation of the SRT sequence, depression, and additional measures of learning, memory, and intelligence were included to explore the source and specificity of potential learning deficits.There was no between-group difference in baseline reaction time, indicating that potential differences between the learning curves of the two groups could not be attributed to an overall reduction in response speed in the SCI group. Unlike controls, the SCI group showed no decline in reaction time over the first six blocks of the SRT task and no advantage for the initially presented sequence over the novel interference sequence. Meanwhile, no group differences were found in explicit learning, depression, or any additional cognitive measures.The dissociation between impaired implicit learning and intact declarative memory represents novel empirical evidence of a specific implicit procedural learning deficit following SCI, with broad implications for rehabilitation and adjustment.

  1. Abnormal functional connectivity and cortical integrity influence dominant hand motor disability in multiple sclerosis: a multimodal analysis.

    Science.gov (United States)

    Zhong, Jidan; Nantes, Julia C; Holmes, Scott A; Gallant, Serge; Narayanan, Sridar; Koski, Lisa

    2016-12-01

    Functional reorganization and structural damage occur in the brains of people with multiple sclerosis (MS) throughout the disease course. However, the relationship between resting-state functional connectivity (FC) reorganization in the sensorimotor network and motor disability in MS is not well understood. This study used resting-state fMRI, T1-weighted and T2-weighted, and magnetization transfer (MT) imaging to investigate the relationship between abnormal FC in the sensorimotor network and upper limb motor disability in people with MS, as well as the impact of disease-related structural abnormalities within this network. Specifically, the differences in FC of the left hemisphere hand motor region between MS participants with preserved (n = 17) and impaired (n = 26) right hand function, compared with healthy controls (n = 20) was investigated. Differences in brain atrophy and MT ratio measured at the global and regional levels were also investigated between the three groups. Motor preserved MS participants had stronger FC in structurally intact visual information processing regions relative to motor impaired MS participants. Motor impaired MS participants showed weaker FC in the sensorimotor and somatosensory association cortices and more severe structural damage throughout the brain compared with the other groups. Logistic regression analysis showed that regional MTR predicted motor disability beyond the impact of global atrophy whereas regional grey matter volume did not. More importantly, as the first multimodal analysis combining resting-state fMRI, T1-weighted, T2-weighted and MTR images in MS, we demonstrate how a combination of structural and functional changes may contribute to motor impairment or preservation in MS. Hum Brain Mapp 37:4262-4275, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  2. Motor Planning Error: Toward Measuring Cognitive Frailty in Older Adults Using Wearables

    Directory of Open Access Journals (Sweden)

    He Zhou

    2018-03-01

    Full Text Available Practical tools which can be quickly administered are needed for measuring subtle changes in cognitive–motor performance over time. Frailty together with cognitive impairment, or ‘cognitive frailty’, are shown to be strong and independent predictors of cognitive decline over time. We have developed an interactive instrumented trail-making task (iTMT platform, which allows quantification of motor planning error (MPE through a series of ankle reaching tasks. In this study, we examined the accuracy of MPE in identifying cognitive frailty in older adults. Thirty-two older adults (age = 77.3 ± 9.1 years, body-mass-index = 25.3 ± 4.7 kg/m2, female = 38% were recruited. Using either the Mini-Mental State Examination or Montreal Cognitive Assessment (MoCA, 16 subjects were classified as cognitive-intact and 16 were classified as cognitive-impaired. In addition, 12 young-healthy subjects (age = 26.0 ± 5.2 years, body-mass-index = 25.3 ± 3.9 kg/m2, female = 33% were recruited to establish a healthy benchmark. Subjects completed the iTMT, using an ankle-worn sensor, which transforms ankle motion into navigation of a computer cursor. The iTMT task included reaching five indexed target circles (including numbers 1-to-3 and letters A&B placed in random order on the computer-screen by moving the ankle-joint while standing. The ankle-sensor quantifies MPE through analysis of the pattern of ankle velocity. MPE was defined as percentage of time deviation between subject’s maximum ankle velocity and the optimal maximum ankle velocity, which is halfway through the reaching pathway. Data from gait tests, including single task and dual task walking, were also collected to determine cognitive–motor performance. The average MPE in young-healthy, elderly cognitive-intact, and elderly cognitive-impaired groups was 11.1 ± 5.7%, 20.3 ± 9.6%, and 34.1 ± 4.2% (p < 0.001, respectively. Large effect sizes (Cohen’s d = 1.17–4.56 were observed for

  3. (Photosynthesis in intact plants)

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    Progress in the two years since the last renewal application has been excellent. We have made substantial contributions on both main fronts of the projects, and are particularly happy with the progress of our research on intact plants. The approach of basing our field work on a sound foundation of laboratory studies has enabled is to use methods which provide unambiguous assays of well characterized reactions. We have also made excellent progress in several laboratory studies which will have direct applications in future field work, and have introduced to the laboratory a range of molecular genetics techniques which will allow us to explore new options in the attempt to understand function at the level of molecular structure.

  4. Does human leukocyte elastase degrade intact skin elastin?

    DEFF Research Database (Denmark)

    Schmelzer, Christian E H; Jung, Michael C; Wohlrab, Johannes

    2012-01-01

    This study aimed to investigate the susceptibility of intact fibrillar human elastin to human leukocyte elastase and cathepsin G. Elastin is a vital protein of the extracellular matrix of vertebrates, and provides exceptional properties including elasticity and tensile strength to many tissues...... and organs, including the aorta, lung, cartilage, elastic ligaments and skin, and is thus critical for their long-term function. Mature elastin is an insoluble and extremely durable protein that undergoes very little turnover, but sustained exposure to proteases may lead to irreversible and severe damage......, and thus to functional loss of the elastic fiber network. Hence, it is a key issue to understand which enzymes actually initiate elastolysis under certain pathological conditions or during intrinsic aging. In this paper, we provide a complete workflow for isolation of pure and intact elastin from very...

  5. DNA synthesis in periportal and perivenous hepatocytes of intact and hepatectomized young mice.

    Science.gov (United States)

    Fernández-Blanco, A; Inda, A M; Errecalde, A L

    2015-01-01

    DNA synthesis of hepatocytes in two areas of Intact and Hepatectomized young mice liver along a circadian period was studied. DNA synthesis was significantly different at all analyzed time points in Intact and Hepatectomized animals. Differences between periportal and perivenous hepatocytes were found in hepatectomized animals at 04/42 and 08/46 hr of day/hour post-hepatectomy. DNAs peak in periportal hepatocytes regenerating liver occurs 4 hr earlier than in perivenous hepatocytes, probably reflecting their shorter G1 phase. Besides, daily mean values of regenerating livers were higher than those observed in Intact animals, as a consequence of surgical removal.

  6. Multi-Axis Prosthetic Knee Resembles Alpine Skiing Movements of an Intact Leg

    Science.gov (United States)

    Demšar, Ivan; Duhovnik, Jože; Lešnik, Blaž; Supej, Matej

    2015-01-01

    The purpose of the study was to analyse the flexion angles of the ski boot, ankle and knee joints of an above-knee prosthesis and to compare them with an intact leg and a control group of skiers. One subject with an above-knee amputation of the right leg and eight healthy subjects simulated the movement of a skiing turn by performing two-leg squats in laboratory conditions. By adding additional loads in proportion to body weight (BW; +1/3 BW, +2/3 BW, +3/3 BW), various skiing regimes were simulated. Change of Flexion Angle (CoFA) and Range of Motion (RoM) in the ski boot, ankle and knee joints were calculated and compared. An average RoM in the skiing boot on the side of prosthesis (4.4 ± 1.1°) was significantly lower compared to an intact leg (5.9 ± 1.8°) and the control group (6.5 ± 2.3°). In the ankle joint, the average RoM was determined to be 13.2±2.9° in the prosthesis, 12.7 ± 2.8° in an intact leg and 14.8±3.6 in the control group. However, the RoM of the knee joint in the prosthesis (42.2 ± 4.2°) was significantly larger than that of the intact leg (34.7 ± 4.4°). The average RoM of the knee joint in the control group was 47.8 ± 5.4°. The influences of additional loads on the kinematics of the lower extremities were different on the side of the prosthesis and on the intact leg. In contrast, additional loads did not produce any significant differences in the control group. Although different CoFAs in the ski boot, ankle and knee joints were used, an above-knee prosthesis with a built-in multi-axis prosthetic knee enables comparable leg kinematics in simulated alpine skiing. Key points The RoM in the ski boot on the side of the prosthetic leg was smaller than the RoM of the intact leg and the control group of healthy subjects. The RoM in the ankle joint of prosthetic leg was comparable to that of the intact leg and the control group of healthy subjects. The RoM in the prosthetic knee joint was greater than the RoM in the knee joint of the

  7. Antimicrobial activity of a new intact skin antisepsis formulation.

    Science.gov (United States)

    Russo, Antonello; Viotti, Pier Luigi; Vitali, Matteo; Clementi, Massimo

    2003-04-01

    Different antiseptic formulations have shown limitations when applied to disinfecting intact skin, notably short-term tolerability and/or efficacy. The purpose of this study was optimizing a new antiseptic formulation specifically targeted at intact skin disinfection and evaluating its in vitro microbicidal activity and in vivo efficacy. The biocidal properties of the antiseptic solution containing 0.5% chloramine-T diluted in 50% isopropyl alcohol (Cloral; Eurospital SpA Trieste, Italy) were measured in vitro versus gram-positive-, gram-negative-, and acid-alcohol-resistant germs and fungi with standard suspension tests in the presence of fetal bovine serum. Virus-inhibiting activity was evaluated in vitro against human cytomegalovirus, herpes simplex virus, poliovirus, hepatitis B virus, and hepatitis C virus. Tests used different methods for the different biologic and in vitro replication capacity of these human viruses. Lastly, Cloral tolerability and skin colonization retardation efficacy after disinfection were studied in vivo. The antiseptic under review showed fast and sustained antimicrobial activity. The efficacy of Cloral against clinically important bacterial and viral pathogens and fungi was highlighted under the experimental conditions described in this article. Finally, microbial regrowth lag and no side effects were documented in vivo after disinfection of 11 volunteers. A stable chloramine-T solution in isopropyl alcohol may be suggested for intact skin antisepsis.

  8. Functional MRI activation of somatosensory and motor cortices in a hand-grafted patient with early clinical sensorimotor recovery

    International Nuclear Information System (INIS)

    Neugroschl, C.; Denolin, V.; Schuind, F.; Holder, C. van; David, P.; Baleriaux, D.; Metens, T.

    2005-01-01

    The aim of this study was to investigate somatosensory and motor cortical activity with functional MRI (fMRI) in a hand-grafted patient with early clinical recovery. The patient had motor fMRI examinations before transplantation, and motor and passive tactile stimulations after surgery. His normal hand and a normal group were studied for comparison. A patient with complete brachial plexus palsy was studied to assess the lack of a fMRI signal in somatosensory areas in the case of total axonal disconnection. Stimulating the grafted hand revealed significant activation in the contralateral somatosensory cortical areas in all fMRI examinations. The activation was seen as early as 10 days after surgery; this effect cannot be explained by the known physiological mechanisms of nerve regeneration. Although an imagination effect cannot be excluded, the objective clinical recovery of sensory function led us to formulate the hypothesis that a connection to the somatosensory cortex was rapidly established. Additional cases and fundamental studies are needed to assess this hypothesis, but several observations were compatible with this explanation. Before surgery, imaginary motion of the amputated hand produced less intense responses than executed movements of the intact hand, whereas the normal activation pattern for right-handed subjects was found after surgery, in agreement with the good clinical motor recovery. (orig.)

  9. Investigation of Mitochondrial Dysfunction by Sequential Microplate-Based Respiration Measurements from Intact and Permeabilized Neurons

    Science.gov (United States)

    Clerc, Pascaline; Polster, Brian M.

    2012-01-01

    Mitochondrial dysfunction is a component of many neurodegenerative conditions. Measurement of oxygen consumption from intact neurons enables evaluation of mitochondrial bioenergetics under conditions that are more physiologically realistic compared to isolated mitochondria. However, mechanistic analysis of mitochondrial function in cells is complicated by changing energy demands and lack of substrate control. Here we describe a technique for sequentially measuring respiration from intact and saponin-permeabilized cortical neurons on single microplates. This technique allows control of substrates to individual electron transport chain complexes following permeabilization, as well as side-by-side comparisons to intact cells. To illustrate the utility of the technique, we demonstrate that inhibition of respiration by the drug KB-R7943 in intact neurons is relieved by delivery of the complex II substrate succinate, but not by complex I substrates, via acute saponin permeabilization. In contrast, methyl succinate, a putative cell permeable complex II substrate, failed to rescue respiration in intact neurons and was a poor complex II substrate in permeabilized cells. Sequential measurements of intact and permeabilized cell respiration should be particularly useful for evaluating indirect mitochondrial toxicity due to drugs or cellular signaling events which cannot be readily studied using isolated mitochondria. PMID:22496810

  10. Motor Neurons

    DEFF Research Database (Denmark)

    Hounsgaard, Jorn

    2017-01-01

    Motor neurons translate synaptic input from widely distributed premotor networks into patterns of action potentials that orchestrate motor unit force and motor behavior. Intercalated between the CNS and muscles, motor neurons add to and adjust the final motor command. The identity and functional...... in in vitro preparations is far from complete. Nevertheless, a foundation has been provided for pursuing functional significance of intrinsic response properties in motoneurons in vivo during motor behavior at levels from molecules to systems....

  11. Impulse radar scanning of intact salt at the Avery Island Mine

    International Nuclear Information System (INIS)

    Cook, C.W.

    1980-05-01

    A series of experiments was run in the Avery Island Mine to evaluate the capability of an impulse radar to locate anomalies and simulated waste targets in intact dome salt. Voids in salt were difficult to detect. On the positive side, metal targets and simulated waste (glass) were easily located in intact salt. Radar scanning at ranges of greater than 25 meters and short-range resolution of target positions to within a few centimeters were achieved

  12. Performance of intact and partially degraded concrete barriers in limiting fluid flow

    International Nuclear Information System (INIS)

    Walton, J.C.; Seitz, R.R.

    1991-07-01

    Concrete barriers will play a critical role in the long-term isolation of low-level radioactive wastes. Over time the barriers will degrade, and in many cases, the fundamental processes controlling performance of the barriers will be different for intact and degraded conditions. This document examines factors controlling fluid flow through intact and degraded concrete disposal facilities. Simplified models are presented fro predicting build up of fluid above a vault; fluid flow through and around intact vaults, through flaws in coatings/liners applied to a vault, and through cracks in a concrete vault; and the influence of different backfill materials around the outside of the vault. Example calculations are presented to illustrate the parameters and processes that influence fluid flow. 46 refs., 49 figs., 2 tabs

  13. Bioavailability and in vivo metabolism of intact glucosinolates

    DEFF Research Database (Denmark)

    Sørensen, Jens Christian; Frandsen, Heidi Blok; Jensen, Søren Krogh

    2016-01-01

    Health benefits associated with consumption of cruciferous vegetables have received considerable attention with a hitherto focus on the role and bioactivity of glucosinolate degradation products. We investigated the in vivo metabolism of intact glucosinolates by following their fate in digesta an...

  14. Independent evolution of neurotoxin and flagellar genetic loci in proteolytic Clostridium botulinum.

    Science.gov (United States)

    Carter, Andrew T; Paul, Catherine J; Mason, David R; Twine, Susan M; Alston, Mark J; Logan, Susan M; Austin, John W; Peck, Michael W

    2009-03-19

    Proteolytic Clostridium botulinum is the causative agent of botulism, a severe neuroparalytic illness. Given the severity of botulism, surprisingly little is known of the population structure, biology, phylogeny or evolution of C. botulinum. The recent determination of the genome sequence of C. botulinum has allowed comparative genomic indexing using a DNA microarray. Whole genome microarray analysis revealed that 63% of the coding sequences (CDSs) present in reference strain ATCC 3502 were common to all 61 widely-representative strains of proteolytic C. botulinum and the closely related C. sporogenes tested. This indicates a relatively stable genome. There was, however, evidence for recombination and genetic exchange, in particular within the neurotoxin gene and cluster (including transfer of neurotoxin genes to C. sporogenes), and the flagellar glycosylation island (FGI). These two loci appear to have evolved independently from each other, and from the remainder of the genetic complement. A number of strains were atypical; for example, while 10 out of 14 strains that formed type A1 toxin gave almost identical profiles in whole genome, neurotoxin cluster and FGI analyses, the other four strains showed divergent properties. Furthermore, a new neurotoxin sub-type (A5) has been discovered in strains from heroin-associated wound botulism cases. For the first time, differences in glycosylation profiles of the flagella could be linked to differences in the gene content of the FGI. Proteolytic C. botulinum has a stable genome backbone containing specific regions of genetic heterogeneity. These include the neurotoxin gene cluster and the FGI, each having evolved independently of each other and the remainder of the genetic complement. Analysis of these genetic components provides a high degree of discrimination of strains of proteolytic C. botulinum, and is suitable for clinical and forensic investigations of botulism outbreaks.

  15. Independent evolution of neurotoxin and flagellar genetic loci in proteolytic Clostridium botulinum

    Directory of Open Access Journals (Sweden)

    Twine Susan M

    2009-03-01

    Full Text Available Abstract Background Proteolytic Clostridium botulinum is the causative agent of botulism, a severe neuroparalytic illness. Given the severity of botulism, surprisingly little is known of the population structure, biology, phylogeny or evolution of C. botulinum. The recent determination of the genome sequence of C. botulinum has allowed comparative genomic indexing using a DNA microarray. Results Whole genome microarray analysis revealed that 63% of the coding sequences (CDSs present in reference strain ATCC 3502 were common to all 61 widely-representative strains of proteolytic C. botulinum and the closely related C. sporogenes tested. This indicates a relatively stable genome. There was, however, evidence for recombination and genetic exchange, in particular within the neurotoxin gene and cluster (including transfer of neurotoxin genes to C. sporogenes, and the flagellar glycosylation island (FGI. These two loci appear to have evolved independently from each other, and from the remainder of the genetic complement. A number of strains were atypical; for example, while 10 out of 14 strains that formed type A1 toxin gave almost identical profiles in whole genome, neurotoxin cluster and FGI analyses, the other four strains showed divergent properties. Furthermore, a new neurotoxin sub-type (A5 has been discovered in strains from heroin-associated wound botulism cases. For the first time, differences in glycosylation profiles of the flagella could be linked to differences in the gene content of the FGI. Conclusion Proteolytic C. botulinum has a stable genome backbone containing specific regions of genetic heterogeneity. These include the neurotoxin gene cluster and the FGI, each having evolved independently of each other and the remainder of the genetic complement. Analysis of these genetic components provides a high degree of discrimination of strains of proteolytic C. botulinum, and is suitable for clinical and forensic investigations of botulism

  16. Learning fast accurate movements requires intact frontostriatal circuits

    Directory of Open Access Journals (Sweden)

    Britne eShabbott

    2013-11-01

    Full Text Available The basal ganglia are known to play a crucial role in movement execution, but their importance for motor skill learning remains unclear. Obstacles to our understanding include the lack of a universally accepted definition of motor skill learning (definition confound, and difficulties in distinguishing learning deficits from execution impairments (performance confound. We studied how healthy subjects and subjects with a basal ganglia disorder learn fast accurate reaching movements, and we addressed the definition and performance confounds by: 1 focusing on an operationally defined core element of motor skill learning (speed-accuracy learning, and 2 using normal variation in initial performance to separate movement execution impairment from motor learning abnormalities. We measured motor skill learning learning as performance improvement in a reaching task with a speed-accuracy trade-off. We compared the performance of subjects with Huntington’s disease (HD, a neurodegenerative basal ganglia disorder, to that of premanifest carriers of the HD mutation and of control subjects. The initial movements of HD subjects were less skilled (slower and/or less accurate than those of control subjects. To factor out these differences in initial execution, we modeled the relationship between learning and baseline performance in control subjects. Subjects with HD exhibited a clear learning impairment that was not explained by differences in initial performance. These results support a role for the basal ganglia in both movement execution and motor skill learning.

  17. Differential activation of an identified motor neuron and neuromodulation provide Aplysia's retractor muscle an additional function.

    Science.gov (United States)

    McManus, Jeffrey M; Lu, Hui; Cullins, Miranda J; Chiel, Hillel J

    2014-08-15

    To survive, animals must use the same peripheral structures to perform a variety of tasks. How does a nervous system employ one muscle to perform multiple functions? We addressed this question through work on the I3 jaw muscle of the marine mollusk Aplysia californica's feeding system. This muscle mediates retraction of Aplysia's food grasper in multiple feeding responses and is innervated by a pool of identified neurons that activate different muscle regions. One I3 motor neuron, B38, is active in the protraction phase, rather than the retraction phase, suggesting the muscle has an additional function. We used intracellular, extracellular, and muscle force recordings in several in vitro preparations as well as recordings of nerve and muscle activity from intact, behaving animals to characterize B38's activation of the muscle and its activity in different behavior types. We show that B38 specifically activates the anterior region of I3 and is specifically recruited during one behavior, swallowing. The function of this protraction-phase jaw muscle contraction is to hold food; thus the I3 muscle has an additional function beyond mediating retraction. We additionally show that B38's typical activity during in vivo swallowing is insufficient to generate force in an unmodulated muscle and that intrinsic and extrinsic modulation shift the force-frequency relationship to allow contraction. Using methods that traverse levels from individual neuron to muscle to intact animal, we show how regional muscle activation, differential motor neuron recruitment, and neuromodulation are key components in Aplysia's generation of multifunctionality. Copyright © 2014 the American Physiological Society.

  18. MOTORIC STIMULATION RELATED TO FINE MOTORIC DEVELOPMENT ON CHILD

    Directory of Open Access Journals (Sweden)

    Mira Triharini

    2017-07-01

    Full Text Available Introduction: Motor developmental stimulation is an activity undertaken to stimulate the children basic skills and so they can grow and develop optimally. Children who obtain a direct stimulus will grow faster than who get less stimulus. Mother’s behavior of stimulation is very important for children, it is considering as the basic needs of children and it must be fulfilled. Providing good stimulation could optimize fine motor development in children. The purpose of this study was to analyze mother’s behavior about motor stimulation with fine motor development in toddler age 4-5 years old. Method: Design have been  used in this study was cross sectional. Population were mothers and their toddler in Group A of Dharma Wanita Persatuan Driyorejo Gresik Preschool. Sample were 51 respondents recruited by using purposive sampling technique according to inclusion and exclusion criteria. The independent variable was mother’s behavior about motor stimulation whereas dependent variable was fine motor development in toddler. The data were collected using questionnaire and conducting observation on fine motor development based on Denver Development Screening Test (DDST. Data then analyzed using Spearman Rho (r test to find relation between mother’s behaviors about stimulation motor on their toddler fine motor development. Result: Results  of this study showed that there were correlations between mother’s knowledge and fine motor development in toddler (p=0.000, between mother’s attitude and fine motor development in toddler (p=0.000, and between mother’s actions and fine motor development in toddler (p=0.000. Analysis: In sort study found that there were relation between fine motor development and mother’s behavior. Discussion: Therefore mother’s behavior needed to be improved. Further research about stimulation motor and fine motor development aspects in toddler is required.

  19. Memory deficits with intact cognitive control in the methylazoxymethanol acetate (MAM) exposure model of neurodevelopmental insult.

    Science.gov (United States)

    O'Reilly, Kally C; Perica, Maria I; Fenton, André A

    2016-10-01

    Cognitive impairments are amongst the most debilitating deficits of schizophrenia and the best predictor of functional outcome. Schizophrenia is hypothesized to have a neurodevelopmental origin, making animal models of neurodevelopmental insult important for testing predictions that early insults will impair cognitive function. Rats exposed to methylazoxymethanol acetate (MAM) at gestational day 17 display morphological, physiological and behavioral abnormalities relevant to schizophrenia. Here we investigate the cognitive abilities of adult MAM rats. We examined brain activity in MAM rats by histochemically assessing cytochrome oxidase enzyme activity, a metabolic marker of neuronal activity. To assess cognition, we used a hippocampus-dependent two-frame active place avoidance paradigm to examine learning and spatial memory, as well as cognitive control and flexibility using the same environment and evaluating the same set of behaviors. We confirmed that adult MAM rats have altered hippocampal morphology and brain function, and that they are hyperactive in an open field. The latter likely indicates MAM rats have a sensorimotor gating deficit that is common to many animal models used for schizophrenia research. On first inspection, cognitive control seems impaired in MAM rats, indicated by more errors during the two-frame active place avoidance task. Because MAM rats are hyperactive throughout place avoidance training, we considered the possibility that the hyperlocomotion may account for the apparent cognitive deficits. These deficits were reduced on the basis of measures of cognitive performance that account for motor activity differences. However, though other aspects of memory are intact, the ability of MAM rats to express trial-to-trial memory is delayed compared to control rats. These findings suggest that spatial learning and cognitive abilities are largely intact, that the most prominent cognitive deficit is specific to acquiring memory in the MAM

  20. Occurence of translocations between irradiated and intact chromosomes of Drosophila melanogaster

    International Nuclear Information System (INIS)

    Myasnyankina, E.N.; Abeleva, Eh.A.; Generalova, M.V.

    1980-01-01

    Two translocations between irradiated father and intact mother autosomes are obtained in Drosophila melanogaster. Five out of 283 regular translocations (between the second and the third chromosomes of an irradiated male) are accompanied by a recombination over the second or the third chromosomes. Nine flies out of twenty considered to be recombinants, could originate due to mutations. The data obtained prove that intact female autosomes can take part in the exchange with homologic (recombinations) and heterologic (translocations) irradiated male autosomes

  1. Direct detection of radicals in intact soybean nodules

    DEFF Research Database (Denmark)

    Mathieu, C; Moreau, S; Frendo, P

    1998-01-01

    Electron paramagnetic resonance spectroscopy has been employed to examine the nature of the metal ions and radicals present in intact root nodules of soybean plants grown in the absence of nitrate. The spectra obtained from nodules of different ages using this non-invasive technique show dramatic...... differences, suggesting that there are both qualitative and quantitative changes in the metal ion and radical species present. A major component of the spectra obtained from young nodules is assigned to a complex (Lb-NO) of nitric oxide (NO.) with the heme protein leghemoglobin (Lb). This Lb-NO species, which...... has not been previously detected in intact root nodules of plants grown in the absence of nitrate, is thought to be formed by reaction of nitric oxide with iron(II) leghemoglobin. The nitric oxide may be generated from arginine via a nitric oxide synthase-like activity present in the nodules...

  2. The electric motor handbook

    Energy Technology Data Exchange (ETDEWEB)

    Hurst, R.W.; Feltham, P. (eds.)

    2004-05-01

    This handbook outlines the important role that electric motors play in modern society. It covers the field of motor applications from various motor types to their use and repair. It also presents practical applications of electric motors and methods on motor efficiency. More than half of all electricity generated, and 75 per cent of all industrial electricity consumption is consumed by electric motors. Electrical personnel must be aware of all factors involved in electric motors in order to choose and apply the appropriate size of electric motor. These factors include efficiency, sizing and proper application. The efficient use and maximum life expectancy of electric motors depends on proper motor protection, control and maintenance. This handbook includes articles from leading experts on electric motors in modern electrical systems. The content includes: design considerations; proper electric motor sizing techniques; optimal electric motor application; electric motor protection technology; electric motor control principles; electric motor maintenance and troubleshooting; induction electric motors; electric motor bearing currents; electric motor bearing lubrication; electromagnetism; electric motor enclosures; electric motor testing; electric motor repair; DC electric motor; electric motor starters; electric motor brushes; industrial electric motors; electric motor diagrams; AC electric motors; electric motor wiring; electric motor service; electric motor rewinding; electric motor winding; diagram of electric motor wiring; electric motor kit; and, troubleshooting electric motors. A directory of motor manufacturers and suppliers was also included. refs., tabs., figs.

  3. Split-phase motor running as capacitor starts motor and as capacitor run motor

    OpenAIRE

    Yahaya Asizehi ENESI; Jacob TSADO; Mark NWOHU; Usman Abraham USMAN; Odu Ayo IMORU

    2016-01-01

    In this paper, the input parameters of a single phase split-phase induction motor is taken to investigate and to study the output performance characteristics of capacitor start and capacitor run induction motor. The value of these input parameters are used in the design characteristics of capacitor run and capacitor start motor with each motor connected to rated or standard capacitor in series with auxiliary winding or starting winding respectively for the normal operational condition. The ma...

  4. Apo and Iron Bound Fur Repression and the Role of Fur in vivo

    Science.gov (United States)

    2010-03-24

    transport (frpB, ceuE) (257). IG-443 is encoded in the intergenic region between fur and HP1033, and is predicted to regulate the flagellar motor ...relationship with the development of gastroesophageal reflux disease (33), Barrett’s esophagus (64), esophageal adenocarcinoma (73), diarrheal diseases (55...active tuberculosis (51), asthma, and other allergic disorders (7, 13, 53). Because of this, a vaccination or therapeutic approach to abrogate H

  5. Segmented motor drive - with multi-phase induction motor

    DEFF Research Database (Denmark)

    Bendixen, Flemming Buus

    of the induction motor is set up. The model is able to calculate dynamical electric, magnetic and mechanic state variables, but initially it is used to calculate static characteristics in motors with different number of phases and different voltage supply shapes. This analysis show i.e. that the efficiency....... The multi-phase motor is selected for further analysis. The project is limited to examine if increasing the number of phases can improve the characteristics for induction motor drives. In the literature it is demonstrated that torque production in a six-phase motor can be increased, if a 3rd harmonic......This PhD project commences in modulation of motor drives, i.e. having the advantage of reducing the number of variants and improves the system reliability at error situations. Four different motor drive topologies with modular construction as common denominator are compared on a general level...

  6. Excitability decreasing central motor plasticity is retained in multiple sclerosis patients

    Directory of Open Access Journals (Sweden)

    Zeller Daniel

    2012-09-01

    Full Text Available Abstract Background Compensation of brain injury in multiple sclerosis (MS may in part work through mechanisms involving neuronal plasticity on local and interregional scales. Mechanisms limiting excessive neuronal activity may have special significance for retention and (re-acquisition of lost motor skills in brain injury. However, previous neurophysiological studies of plasticity in MS have investigated only excitability enhancing plasticity and results from neuroimaging are ambiguous. Thus, the aim of this study was to probe long-term depression-like central motor plasticity utilizing continuous theta-burst stimulation (cTBS, a non-invasive brain stimulation protocol. Because cTBS also may trigger behavioral effects through local interference with neuronal circuits, this approach also permitted investigating the functional role of the primary motor cortex (M1 in force control in patients with MS. Methods We used cTBS and force recordings to examine long-term depression-like central motor plasticity and behavioral consequences of a M1 lesion in 14 patients with stable mild-to-moderate MS (median EDSS 1.5, range 0 to 3.5 and 14 age-matched healthy controls. cTBS consisted of bursts (50 Hz of three subthreshold biphasic magnetic stimuli repeated at 5 Hz for 40 s over the hand area of the left M1. Corticospinal excitability was probed via motor-evoked potentials (MEP in the abductor pollicis brevis muscle over M1 before and after cTBS. Force production performance was assessed in an isometric right thumb abduction task by recording the number of hits into a predefined force window. Results cTBS reduced MEP amplitudes in the contralateral abductor pollicis brevis muscle to a comparable extent in control subjects (69 ± 22% of baseline amplitude, p  Conclusions Long-term depression-like plasticity remains largely intact in mild-to-moderate MS. Increasing brain injury may render the neuronal networks less responsive toward lesion

  7. Motor coordination during gait after anterior cruciate ligament injury: a systematic review of the literature

    Directory of Open Access Journals (Sweden)

    Gustavo Leporace

    2013-08-01

    Full Text Available To investigate the state of art about motor coordination during gait in patients with anterior cruciate ligament (ACL injury. Searches were carried out, limited from 1980 to 2010, in various databases with keywords related to motor coordination, gait and ACL injury. From the analysis of titles and applying the inclusion/exclusion criteria 24 studies were initially selected and, after reading the abstract, eight studies remained in the final analysis. ACL deficient patients tend to have a more rigid and less variable gait, while injured patients with ACL reconstruction have less rigid and more variable gait with respect to healthy individuals. The overall results suggest the existence of differences in motor coordination between the segments with intact and those with injured knee, regardless of ligament reconstruction. ACL injured patients present aspects related to the impairment of the capability to adapt the gait pattern to different environmental conditions, possibly leading to premature knee degeneration. However, the techniques used for biomechanical gait data processing are limited with respect to obtaining information that leads to the development of intervention strategies aimed at the rehabilitation of that injury, since it is not possible to identify the location within the gait cycle where the differences could be explained.

  8. Capillary zone electrophoresis-mass spectromet of intact proteins

    NARCIS (Netherlands)

    Domínguez-Vega, Elena; Haselberg, Rob; Somsen, Govert W.

    2016-01-01

    Capillary electrophoresis (CE) coupled with mass spectrometry (MS) has proven to be a powerful analytical tool for the characterization of intact proteins. It combines the high separation efficiency, short analysis time, and versatility of CE with the mass selectivity and sensitivity offered by MS

  9. 46 CFR 111.70-3 - Motor controllers and motor-control centers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Motor controllers and motor-control centers. 111.70-3... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Motor Circuits, Controllers, and Protection § 111.70-3 Motor controllers and motor-control centers. (a) General. The enclosure for each motor controller or motor-control...

  10. Losing a jewel—Rapid declines in Myanmar’s intact forests from 2002-2014

    Science.gov (United States)

    Horning, Ned; Khaing, Thiri; Thein, Zaw Min; Aung, Kyaw Moe; Aung, Kyaw Htet; Phyo, Paing; Tun, Ye Lin; Oo, Aung Htat; Neil, Anthony; Thu, Win Myo; Songer, Melissa; Huang, Qiongyu; Connette, Grant; Leimgruber, Peter

    2017-01-01

    New and rapid political and economic changes in Myanmar are increasing the pressures on the country’s forests. Yet, little is known about the past and current condition of these forests and how fast they are declining. We mapped forest cover in Myanmar through a consortium of international organizations and environmental non-governmental groups, using freely-available public domain data and open source software tools. We used Landsat satellite imagery to assess the condition and spatial distribution of Myanmar’s intact and degraded forests with special focus on changes in intact forest between 2002 and 2014. We found that forests cover 42,365,729 ha or 63% of Myanmar, making it one of the most forested countries in the region. However, severe logging, expanding plantations, and degradation pose increasing threats. Only 38% of the country’s forests can be considered intact with canopy cover >80%. Between 2002 and 2014, intact forests declined at a rate of 0.94% annually, totaling more than 2 million ha forest loss. Losses can be extremely high locally and we identified 9 townships as forest conversion hotspots. We also delineated 13 large (>100,000 ha) and contiguous intact forest landscapes, which are dispersed across Myanmar. The Northern Forest Complex supports four of these landscapes, totaling over 6.1 million ha of intact forest, followed by the Southern Forest Complex with three landscapes, comprising 1.5 million ha. These remaining contiguous forest landscape should have high priority for protection. Our project demonstrates how open source data and software can be used to develop and share critical information on forests when such data are not readily available elsewhere. We provide all data, code, and outputs freely via the internet at (for scripts: https://bitbucket.org/rsbiodiv/; for the data: http://geonode.themimu.info/layers/geonode%3Amyan_lvl2_smoothed_dec2015_resamp) PMID:28520726

  11. Production of high quality brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) RNA from isolated populations of rat spinal cord motor neurons obtained by Laser Capture Microdissection (LCM).

    Science.gov (United States)

    Mehta, Prachi; Premkumar, Brian; Morris, Renée

    2016-08-03

    The mammalian central nervous system (CNS) is composed of multiple cellular elements, making it challenging to segregate one particular cell type to study their gene expression profile. For instance, as motor neurons represent only 5-10% of the total cell population of the spinal cord, meaningful transcriptional analysis on these neurons is almost impossible to achieve from homogenized spinal cord tissue. A major challenge faced by scientists is to obtain good quality RNA from small amounts of starting material. In this paper, we used Laser Capture Microdissection (LCM) techniques to identify and isolate spinal cord motor neurons. The present analysis revealed that perfusion with paraformaldehyde (PFA) does not alter RNA quality. RNA integrity numbers (RINs) of tissue samples from rubrospinal tract (RST)-transected, intact spinal cord or from whole spinal cord homogenate were all above 8, which indicates intact, high-quality RNA. Levels of mRNA for brain-derived neurotrophic factor (BDNF) or for its tropomyosin receptor kinase B (TrkB) were not affected by rubrospinal tract (RST) transection, a surgical procedure that deprive motor neurons from one of their main supraspinal input. The isolation of pure populations of neurons with LCM techniques allows for robust transcriptional characterization that cannot be achieved with spinal cord homogenates. Such preparations of pure population of motor neurons will provide valuable tools to advance our understanding of the molecular mechanisms underlying spinal cord injury and neuromuscular diseases. In the near future, LCM techniques might be instrumental to the success of gene therapy for these debilitating conditions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Non-intact zona improves development of murine preimplantation ...

    African Journals Online (AJOL)

    ajl5

    2012-09-25

    Sep 25, 2012 ... 2College of Animal Science and Technology, Northwest A & F University, Yangling, ... Key words: Mouse, non-intact zona embryos, adenovirus vector with green fluorescent protein (pAd-GFP), .... Based on microscopic examination, the ZP of some ..... permeable structure of ZP that allowed penetration of.

  13. Neurons other than motor neurons in motor neuron disease.

    Science.gov (United States)

    Ruffoli, Riccardo; Biagioni, Francesca; Busceti, Carla L; Gaglione, Anderson; Ryskalin, Larisa; Gambardella, Stefano; Frati, Alessandro; Fornai, Francesco

    2017-11-01

    Amyotrophic lateral sclerosis (ALS) is typically defined by a loss of motor neurons in the central nervous system. Accordingly, morphological analysis for decades considered motor neurons (in the cortex, brainstem and spinal cord) as the neuronal population selectively involved in ALS. Similarly, this was considered the pathological marker to score disease severity ex vivo both in patients and experimental models. However, the concept of non-autonomous motor neuron death was used recently to indicate the need for additional cell types to produce motor neuron death in ALS. This means that motor neuron loss occurs only when they are connected with other cell types. This concept originally emphasized the need for resident glia as well as non-resident inflammatory cells. Nowadays, the additional role of neurons other than motor neurons emerged in the scenario to induce non-autonomous motor neuron death. In fact, in ALS neurons diverse from motor neurons are involved. These cells play multiple roles in ALS: (i) they participate in the chain of events to produce motor neuron loss; (ii) they may even degenerate more than and before motor neurons. In the present manuscript evidence about multi-neuronal involvement in ALS patients and experimental models is discussed. Specific sub-classes of neurons in the whole spinal cord are reported either to degenerate or to trigger neuronal degeneration, thus portraying ALS as a whole spinal cord disorder rather than a disease affecting motor neurons solely. This is associated with a novel concept in motor neuron disease which recruits abnormal mechanisms of cell to cell communication.

  14. Quantitative Analysis of Human Salivary Gland-Derived Intact Proteome Using Top-Down Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Si; Brown, Joseph N.; Tolic, Nikola; Meng, Da; Liu, Xiaowen; Zhang, Haizhen; Zhao, Rui; Moore, Ronald J.; Pevzner, Pavel A.; Smith, Richard D.; Pasa-Tolic, Ljiljana

    2014-05-31

    There are several notable challenges inherent to fully characterizing the entirety of the human saliva proteome using bottom-up approaches, including polymorphic isoforms, post-translational modifications, unique splice variants, deletions, and truncations. To address these challenges, we have developed a top-down based liquid chromatography-mass spectrometry (LC-MS) approach, which cataloged 20 major human salivary proteins with a total of 83 proteoforms, containing a broad range of post-translational modifications. Among these proteins, several previously reported disease biomarker proteins were identified at the intact protein level, such as beta-2 microglobulin (B2M). In addition, intact glycosylated proteoforms of several saliva proteins were also characterized, including intact N-glycosylated protein prolactin inducible protein (PIP) and O-glycosylated acidic protein rich protein (aPRP). These characterized proteoforms constitute an intact saliva proteoform database, which was used for quantitative comparison of intact salivary proteoforms among six healthy individuals. Human parotid (PS) and submandibular/sublingual gland (SMSL) secretion samples (2 μg of protein each) from six healthy individuals were compared using RPLC coupled with the 12T FTICR mass spectrometer. Significantly different protein and PTM patterns were resolved with high reproducibility between PS and SMSL glands. The results from this study provide further insight into the potential mechanisms of PTM pathways in oral glandular secretion, expanding our knowledge of this complex yet easily accessible fluid. Intact protein LC-MS approach presented herein can potentially be applied for rapid and accurate identification of biomarkers from only a few microliters of human glandular saliva.

  15. Are children who play a sport or a musical instrument better at motor imagery than children who do not?

    Science.gov (United States)

    Dey, Abhishikta; Barnsley, Nadia; Mohan, Rahul; McCormick, Marianne; McAuley, James H; Moseley, G Lorimer

    2012-10-01

    Playing a sport or a musical instrument is presumed to improve motor ability. One would therefore predict that children who play a sport or music are better at motor imagery tasks, which rely on an intact cortical proprioceptive representation and precise motor planning, than children who do not. The authors tested this prediction. This study involved an online questionnaire and then a motor imagery task. The task measured the reaction time (RT) and the accuracy for left/right-hand judgements in children aged 5 to 17 years. Forty pictured hands (20 left), held in various positions and rotated zero, 90°, 180° or 270°, were displayed on a screen. Participants indicated whether the displayed hands were left or right by pressing keys on a keyboard. Fifty-seven children (30 boys; mean±SD age=10±3.3 years) participated. The mean±SD RT was 3015.4±1330.0 ms and the accuracy was 73.9±16.6%. There was no difference in RT between children who played sport, music, neither or both (four-level one-way analysis of variance, p=0.85). There was no difference in accuracy between groups either (Kruskal-Wallis, p=0.46). In a secondary analysis, participants whose parents rated them as being 'clumsy' were no slower (n.s.) but were about 25% less accurate than those rated coordinated or very coordinated (pmusic is associated with better cortical proprioceptive representation and motor planning. Secondary analyses suggest that parent-rated clumsiness is negatively related to motor imagery performance.

  16. Dissecting the molecular mechanisms of intraflagellar transport in Chlamydomonas

    DEFF Research Database (Denmark)

    Pedersen, L. B.; Geimer, S.; Rosenbaum, J. L.

    2006-01-01

    Background The assembly and maintenance of eukaryotic cilia and flagella are mediated by intraflagellar transport (IFT), a bidirectional microtubule (MT)-based transport system. The IFT system consists of anterograde (kinesin-2) and retrograde (cDynein1b) motor complexes and IFT particles...... comprising two complexes, A and B. In the current model for IFT, kinesin-2 carries cDynein1b, IFT particles, and axonemal precursors from the flagellar base to the tip, and cDynein1b transports kinesin-2, IFT particles, and axonemal turnover products from the tip back to the base. Most of the components...... of the IFT system have been identified and characterized, but the mechanisms by which these different components are coordinated and regulated at the flagellar base and tip are unclear. Results Using a variety of Chlamydomonas mutants, we confirm that cDynein1b requires kinesin-2 for transport toward the tip...

  17. Aberrant supplementary motor complex and limbic activity during motor preparation in motor conversion disorder.

    Science.gov (United States)

    Voon, Valerie; Brezing, Christina; Gallea, Cecile; Hallett, Mark

    2011-11-01

    Conversion disorder (CD) is characterized by unexplained neurological symptoms presumed related to psychological issues. The main hypotheses to explain conversion paralysis, characterized by a lack of movement, include impairments in either motor intention or disruption of motor execution, and further, that hyperactive self-monitoring, limbic processing or top-down regulation from higher order frontal regions may interfere with motor execution. We have recently shown that CD with positive abnormal or excessive motor symptoms was associated with greater amygdala activity to arousing stimuli along with greater functional connectivity between the amygdala and supplementary motor area. Here we studied patients with such symptoms focusing on motor initiation. Subjects performed either an internally or externally generated 2-button action selection task in a functional MRI study. Eleven CD patients without major depression and 11 age- and gender-matched normal volunteers were assessed. During both internally and externally generated movement, conversion disorder patients relative to normal volunteers had lower left supplementary motor area (SMA) (implicated in motor initiation) and higher right amygdala, left anterior insula, and bilateral posterior cingulate activity (implicated in assigning emotional salience). These findings were confirmed in a subgroup analysis of patients with tremor symptoms. During internally versus externally generated action in CD patients, the left SMA had lower functional connectivity with bilateral dorsolateral prefrontal cortices. We propose a theory in which previously mapped conversion motor representations may in an arousing context hijack the voluntary action selection system, which is both hypoactive and functionally disconnected from prefrontal top-down regulation. Copyright © 2011 Movement Disorder Society.

  18. Aberrant supplementary motor complex and limbic activity during motor preparation in motor conversion disorder

    Science.gov (United States)

    Voon, V; Brezing, C; Gallea, C; Hallett, M

    2014-01-01

    Background Conversion disorder is characterized by unexplained neurological symptoms presumed related to psychological issues. The main hypotheses to explain conversion paralysis, characterized by a lack of movement, include impairments in either motor intention or disruption of motor execution, and further, that hyperactive self-monitoring, limbic processing or top-down regulation from higher order frontal regions may interfere with motor execution. We have recently shown that conversion disorder with positive abnormal or excessive motor symptoms was associated with greater amygdala activity to arousing stimuli along with greater functional connectivity between the amgydala and supplementary motor area. Here we studied patients with such symptoms focusing on motor initiation. Methods Subjects performed either an internally or externally generated two-button action selection task in a functional MRI study. Results Eleven conversion disorder patients without major depression and 11 age- and gender-matched normal volunteers were assessed. During both internally and externally generated movement, conversion disorder patients relative to normal volunteers had lower left supplementary motor area (SMA) (implicated in motor initiation) and higher right amygdala, left anterior insula and bilateral posterior cingulate activity (implicated in assigning emotional salience). These findings were confirmed in a subgroup analysis of patients with tremor symptoms. During internally versus externally generated action in CD patients, the left SMA had lower functional connectivity with bilateral dorsolateral prefrontal cortices. Conclusion We propose a theory in which previously mapped conversion motor representations may in an arousing context hijack the voluntary action selection system which is both hypoactive and functionally disconnected from prefrontal top-down regulation. PMID:21935985

  19. Near-infrared reflectance spectroscopy for predicting amino acids content in intact processed animal proteins.

    Science.gov (United States)

    De la Haba, Maria José; Garrido-Varo, Ana; Guerrero-Ginel, José Emilio; Pérez-Marín, Dolores C

    2006-10-04

    Near-infrared calibrations were developed for the instantaneous prediction of amino acids composition of processed animal proteins (PAPs). Two sample presentation modes were compared (ground vs intact) for demonstrating the viability of the analysis in the intact form, avoiding the need for milling. Modified partial least-squares (MPLS) equations for the prediction of amino acids in PAPs were developed using the same set of samples (N = 92 PAPs) analyzed in ground and intact form and in three cups differing in the optical window size. The standard error for cross validation (SECV) and the coefficient of determination (1-VR) values yielded with the calibrations developed using the samples analyzed in the intact form showed similar or even better accuracy than those obtained with finely ground samples. The excellent predictive ability (1-VR > 0.90; CV marketing of these important protein feed ingredients, alleviating the costs and time associated with the routine quality controls.

  20. Motor/generator

    Science.gov (United States)

    Hickam, Christopher Dale [Glasford, IL

    2008-05-13

    A motor/generator is provided for connecting between a transmission input shaft and an output shaft of a prime mover. The motor/generator may include a motor/generator housing, a stator mounted to the motor/generator housing, a rotor mounted at least partially within the motor/generator housing and rotatable about a rotor rotation axis, and a transmission-shaft coupler drivingly coupled to the rotor. The transmission-shaft coupler may include a clamp, which may include a base attached to the rotor and a plurality of adjustable jaws.

  1. Application of stepping motor

    International Nuclear Information System (INIS)

    1980-10-01

    This book is divided into three parts, which is about practical using of stepping motor. The first part has six chapters. The contents of the first part are about stepping motor, classification of stepping motor, basic theory og stepping motor, characteristic and basic words, types and characteristic of stepping motor in hybrid type and basic control of stepping motor. The second part deals with application of stepping motor with hardware of stepping motor control, stepping motor control by microcomputer and software of stepping motor control. The last part mentions choice of stepping motor system, examples of stepping motor, measurement of stepping motor and practical cases of application of stepping motor.

  2. Mass distribution and spatial organization of the linear bacterial motor of Spiroplasma citri R8A2.

    Science.gov (United States)

    Trachtenberg, Shlomo; Andrews, S Brian; Leapman, Richard D

    2003-03-01

    In the simple, helical, wall-less bacterial genus Spiroplasma, chemotaxis and motility are effected by a linear, contractile motor arranged as a flat cytoskeletal ribbon attached to the inner side of the membrane along the shortest helical line. With scanning transmission electron microscopy and diffraction analysis, we determined the hierarchical and spatial organization of the cytoskeleton of Spiroplasma citri R8A2. The structural unit appears to be a fibril, approximately 5 nm wide, composed of dimers of a 59-kDa protein; each ribbon is assembled from seven fibril pairs. The functional unit of the intact ribbon is a pair of aligned fibrils, along which pairs of dimers form tetrameric ring-like repeats. On average, isolated and purified ribbons contain 14 fibrils or seven well-aligned fibril pairs, which are the same structures observed in the intact cell. Scanning transmission electron microscopy mass analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified cytoskeletons indicate that the 59-kDa protein is the only constituent of the ribbons.

  3. Sleep parameters, functional status and time post-stroke are associated with off-line motor skill learning in people with chronic stroke

    Directory of Open Access Journals (Sweden)

    Catherine eSiengsukon

    2015-10-01

    Full Text Available Background: Mounting evidence demonstrates that individuals with stroke benefit from sleep to enhance learning of a motor task. While stage NREM2 sleep and REM sleep have been associated with off-line motor skill learning in neurologically-intact individuals, it remains unknown which sleep parameters or specific sleep stages are associated with off-line motor skill learning in individuals with stroke. Methods: Twenty individuals with chronic stroke (> 6 months following stroke and 10 neurologically slept for three consecutive nights in a sleep laboratory with polysomnography. Participants practiced a tracking task the morning before the third night and underwent a retention test the morning following the third night. Off-line learning on the tracking task was assessed. Pearson’s correlations assessed for associations between the magnitude of off-line learning and sleep variables, age, upper extremity motor function, stroke severity, depression and time since stroke occurrence.Results: Individuals with stroke performed with significantly less error on the tracking task following a night of sleep (p=.006 while the control participants did not (p=.816. Increased sleep efficiency (r= -.285, less time spent in stage NREM3 sleep (r=.260, and more time spent in stage REM sleep (r= -.266 was weakly-to-moderately associated with increased magnitude of off-line motor learning. Furthermore, higher upper-extremity motor function (r = -.400, lower stroke severity (r = .360, and less time since stroke occurrence (r=.311 were moderately associated with increased magnitude of off-line motor learning. Conclusion: This study is the first study to provide insight into which sleep stages and individual characteristics may be associated with off-line learning in people with stroke. Future work should continue to understand which factors or combination of factors promote off-line motor learning in people with neurologic injury to best promote motor recovery in

  4. Aboveground Biomass Variability Across Intact and Degraded Forests in the Brazilian Amazon

    Science.gov (United States)

    Longo, Marcos; Keller, Michael; Dos-Santos, Maiza N.; Leitold, Veronika; Pinage, Ekena R.; Baccini, Alessandro; Saatchi, Sassan; Nogueira, Euler M.; Batistella, Mateus; Morton, Douglas C.

    2016-01-01

    Deforestation rates have declined in the Brazilian Amazon since 2005, yet degradation from logging, re, and fragmentation has continued in frontier forests. In this study we quantified the aboveground carbon density (ACD) in intact and degraded forests using the largest data set of integrated forest inventory plots (n 359) and airborne lidar data (18,000 ha) assembled to date for the Brazilian Amazon. We developed statistical models relating inventory ACD estimates to lidar metrics that explained70 of the variance across forest types. Airborne lidar-ACD estimates for intact forests ranged between 5.0 +/- 2.5 and 31.9 +/- 10.8 kg C m(exp -2). Degradation carbon losses were large and persistent. Sites that burned multiple times within a decade lost up to 15.0 +/- 0.7 kg C m(-2)(94%) of ACD. Forests that burned nearly15 years ago had between 4.1 +/- 0.5 and 6.8 +/- 0.3 kg C m(exp -2) (22-40%) less ACD than intact forests. Even for low-impact logging disturbances, ACD was between 0.7 +/- 0.3 and 4.4 +/- 0.4 kg C m(exp -2)(4-21%) lower than unlogged forests. Comparing biomass estimates from airborne lidar to existing biomass maps, we found that regional and pan-tropical products consistently overestimated ACD in degraded forests, under-estimated ACD in intact forests, and showed little sensitivity to res and logging. Fine-scale heterogeneity in ACD across intact and degraded forests highlights the benefits of airborne lidar for carbon mapping. Differences between airborne lidar and regional biomass maps underscore the need to improve and update biomass estimates for dynamic land use frontiers, to better characterize deforestation and degradation carbon emissions for regional carbon budgets and Reduce Emissions from Deforestation and forest Degradation(REDD+).

  5. Endogenous rhythm and pattern-generating circuit interactions in cockroach motor centres

    Directory of Open Access Journals (Sweden)

    Izhak David

    2016-09-01

    Full Text Available Cockroaches are rapid and stable runners whose gaits emerge from the intricate, and not fully resolved, interplay between endogenous oscillatory pattern-generating networks and sensory feedback that shapes their rhythmic output. Here we studied the endogenous motor output of a brainless, deafferented preparation. We monitored the pilocarpine-induced rhythmic activity of levator and depressor motor neurons in the mesothoracic and metathoracic segments in order to reveal the oscillatory networks’ architecture and interactions. Data analyses included phase relations, latencies between and overlaps of rhythmic bursts, spike frequencies, and the dependence of these parameters on cycle frequency. We found that, overall, ipsilateral connections are stronger than contralateral ones. Our findings revealed asymmetries in connectivity among the different ganglia, in which meta-to-mesothoracic ascending coupling is stronger than meso-to-metathoracic descending coupling. Within-ganglion coupling between the metathoracic hemiganglia is stronger than that in the mesothoracic ganglion. We also report differences in the role and mode of operation of homologue network units (manifested by levator and depressor nerve activity. Many observed characteristics are similar to those exhibited by intact animals, suggesting a dominant role for feedforward control in cockroach locomotion. Based on these data we posit a connectivity scheme among components of the locomotion pattern generating system.

  6. Comparison of functional recovery of manual dexterity after unilateral spinal cord lesion or motor cortex lesion in adult macaque monkeys

    Directory of Open Access Journals (Sweden)

    Florence eHoogewoud

    2013-07-01

    Full Text Available In relation to mechanisms involved in functional recovery of manual dexterity from cervical cord injury or from motor cortical injury, our goal was to determine whether the movements that characterize post-lesion functional recovery are comparable to original movement patterns or do monkeys adopt distinct strategies to compensate the deficits depending on the type of lesion? To this aim, data derived from earlier studies, using a skilled finger task (the modified Brinkman board from which pellets are retrieved from vertical or horizontal slots, in spinal cord and motor cortex injured monkeys were analyzed and compared. Twelve adult macaque monkeys were subjected to a hemi-section of the cervical cord (n=6 or to a unilateral excitotoxic lesion of the hand representation in the primary motor cortex (n=6. In addition, in each subgroup, one half of monkeys (n=3 were treated for 30 days with a function blocking antibody against the neurite growth inhibitory protein Nogo-A, while the other half (n=3 represented control animals. The motor deficits, and the extent and time course of functional recovery were assessed.For some of the parameters investigated (wrist angle for horizontal slots and movement types distribution for vertical slots after cervical injury; movement types distribution for horizontal slots after motor cortex lesion, post-lesion restoration of the original movement patterns (true recovery led to a quantitatively better functional recovery. In the motor cortex lesion groups, pharmacological reversible inactivation experiments showed that the peri-lesion territory of the primary motor cortex or re-arranged, spared domain of the lesion zone, played a major role in the functional recovery, together with the ipsilesional intact premotor cortex.

  7. Intranasal trigeminal function in subjects with and without an intact sense of smell.

    Science.gov (United States)

    Iannilli, E; Gerber, J; Frasnelli, J; Hummel, T

    2007-03-30

    The intranasal trigeminal system is involved in the perception of odors. To investigate the cerebral processing of sensory information from the trigeminal nerve in detail we studied subjects with and without olfactory function using functional magnetic resonance imaging. A normosmic group (n=12) was compared with a group of anosmic subjects (n=11). For trigeminal stimulation gaseous CO(2) was used. Following right-sided stimulation with CO(2) controls exhibited a stronger right-sided cerebral activation than anosmic subjects. Stronger activation was found in controls compared to anosmic subjects for the right prefrontal cortex, the right somatosensory cortex (SI), and the left parietal insula. In contrast, relatively higher activation was found in anosmic subjects for the left supplementary motor area in the frontal lobe, the right superior and middle temporal lobe, the left parahippocampal gyrus in the limbic lobe, and the sub-lobar region of the left putamen and right insula which was mostly due to a decreased BOLD signal of controls in these areas. Additional conjunction analysis revealed that activated areas common to the two groups were the cerebellum and the right premotor frontal cortex. These data suggest that the processing of the trigeminally mediated information is different in the presence or absence of an intact sense of smell, pointing towards the intimate connection between the two chemosensory systems.

  8. Phosphorylation of intact erythrocytes in human muscular dystrophy

    International Nuclear Information System (INIS)

    Johnson, R.M.; Nigro, M.

    1986-01-01

    The uptake of exogenous 32 Pi into the membrane proteins of intact erythrocytes was measured in 8 patients with Duchenne muscular dystrophy. No abnormalities were noted after autoradiographic analysis. This contrasts with earlier results obtained when isolated membranes were phosphorylated with gamma-[ 32 P]ATP, and suggests a possible reinterpretation of those experiments

  9. Sympathetic Nervous Regulation of Calcium and Action Potential Alternans in the Intact Heart.

    Science.gov (United States)

    Winter, James; Bishop, Martin J; Wilder, Catherine D E; O'Shea, Christopher; Pavlovic, Davor; Shattock, Michael J

    2018-01-01

    Rationale: Arrhythmogenic cardiac alternans are thought to be an important determinant for the initiation of ventricular fibrillation. There is limited information on the effects of sympathetic nerve stimulation (SNS) on alternans in the intact heart and the conclusions of existing studies, focused on investigating electrical alternans, are conflicted. Meanwhile, several lines of evidence implicate instabilities in Ca handling, not electrical restitution, as the primary mechanism underpinning alternans. Despite this, there have been no studies on Ca alternans and SNS in the intact heart. The present study sought to address this, by application of voltage and Ca optical mapping for the simultaneous study of APD and Ca alternans in the intact guinea pig heart during direct SNS. Objective : To determine the effects of SNS on APD and Ca alternans in the intact guinea pig heart and to examine the mechanism(s) by which the effects of SNS are mediated. Methods and Results : Studies utilized simultaneous voltage and Ca optical mapping in isolated guinea pig hearts with intact innervation. Alternans were induced using a rapid dynamic pacing protocol. SNS was associated with rate-independent shortening of action potential duration (APD) and the suppression of APD and Ca alternans, as indicated by a shift in the alternans threshold to faster pacing rates. Qualitatively similar results were observed with exogenous noradrenaline perfusion. In contrast with previous reports, both SNS and noradrenaline acted to flatten the slope of the electrical restitution curve. Pharmacological block of the slow delayed rectifying potassium current (I Ks ), sufficient to abolish I Ks -mediated APD-adaptation, partially reversed the effects of SNS on pacing-induced alternans. Treatment with cyclopiazonic acid, an inhibitor of the sarco(endo)plasmic reticulum ATPase, had opposite effects to that of SNS, acting to increase susceptibility to alternans, and suggesting that accelerated Ca reuptake

  10. Performance Comparison between a Permanent Magnet Synchronous Motor and an Induction Motor as a Traction Motor for High Speed Train

    Science.gov (United States)

    Kondo, Minoru; Kawamura, Junya; Terauchi, Nobuo

    Performance tests are carried out to demonstrate the superiority of a permanent magnet synchronous motor to an induction motor as a traction motor for high-speed train. A prototype motor was manufactured by replacing the rotor of a conventional induction motor. The test results show that the permanent magnet motor is lighter, efficient and more silent than the induction motor because of the different rotor structure.

  11. Spontaneous and light-induced photon emission from intact brains of chick embryos

    Institute of Scientific and Technical Information of China (English)

    张锦珠; 于文斗; 孙彤

    1997-01-01

    Photon emission (PE) and light-induced photon emission(LPE) of intact brains isolated from chick embryos have been measured by using the single photon counting device. Experimental results showed that the intensi-ty level of photon emission was detected to be higher from intact brain than from the medium in which the brain was immerged during measuring, and the emission intensity was related to the developmental stages, the healthy situation of the measured embryos, and the freshness of isolated brains as well. After white light illumination, a short-life de-layed emission from intact brains was observed, and its relaxation behavior followed a hyperbolic rather than an expo-nential law. According to the hypothesis of biophoton emission originating from a delocalized coherent electromagnetic field and Frohlich’s idea of coherent long-range interactions in biological systems, discussions were made on the signifi-cance of photon emission in studying cell communication, biological regulation, living system’

  12. Predictors of attachment security in preschool children from intact and divorced families.

    Science.gov (United States)

    Nair, Hira; Murray, Ann D

    2005-09-01

    The authors selected 58 mother-child dyads from divorced and intact families to participate in a study on the impact of divorce on preschoolers' attachment security. The authors explored pathways that lead to security of attachment. They found that mothers from divorced families were younger, had lower income levels, and had lower levels of education compared with their intact counterparts. Divorced mothers also reported significantly higher levels of stress, depression, need for social support, and conflict with their spouses. Mothers from intact families were more likely to use positive (authoritative) parenting styles compared with divorced mothers. Children in the divorced group had lower security scores on the Attachment Q-Set instrument (E. Waters, 1995). Regression analyses indicated that parenting style made a direct (independent) contribution to attachment security. In addition, temperament was related to attachment security, but temperament did not diminish the association of parenting style with attachment security. Furthermore, regression analyses indicated that the relationship of divorce to attachment security was mediated by parenting style.

  13. Toward best practices in data processing and analysis for intact biotherapeutics by MS in quantitative bioanalysis.

    Science.gov (United States)

    Kellie, John F; Kehler, Jonathan R; Karlinsey, Molly Z; Summerfield, Scott G

    2017-12-01

    Typically, quantitation of biotherapeutics from biological matrices by LC-MS is based on a surrogate peptide approach to determine molecule concentration. Recent efforts have focused on quantitation of the intact protein molecules or larger mass subunits of monoclonal antibodies. To date, there has been limited guidance for large or intact protein mass quantitation for quantitative bioanalysis. Intact- and subunit-level analyses of biotherapeutics from biological matrices are performed at 12-25 kDa mass range with quantitation data presented. Linearity, bias and other metrics are presented along with recommendations made on the viability of existing quantitation approaches. This communication is intended to start a discussion around intact protein data analysis and processing, recognizing that other published contributions will be required.

  14. SOLITARY CHEMORECEPTOR CELL SURVIVAL IS INDEPENDENT OF INTACT TRIGEMINAL INNERVATION

    Science.gov (United States)

    Gulbransen, Brian; Silver, Wayne; Finger, Tom

    2008-01-01

    Nasal solitary chemoreceptor cells (SCCs) are a population of specialized chemosensory epithelial cells presumed to broaden trigeminal chemoreceptivity in mammals (Finger et al., 2003). SCCs are innervated by peptidergic trigeminal nerve fibers (Finger et al., 2003) but it is currently unknown if intact innervation is necessary for SCC development or survival. We tested the dependence of SCCs on innervation by eliminating trigeminal nerve fibers during development with neurogenin-1 knockout mice, during early postnatal development with capsaicin desensitization, and during adulthood with trigeminal lesioning. Our results demonstrate that elimination of innervation at any of these times does not result in decreased SCC numbers. In conclusion, neither SCC development nor mature cell maintenance is dependent on intact trigeminal innervation. PMID:18300260

  15. Loss of FliL alters Proteus mirabilis surface sensing and temperature-dependent swarming.

    Science.gov (United States)

    Lee, Yi-Ying; Belas, Robert

    2015-01-01

    Proteus mirabilis is a dimorphic motile bacterium well known for its flagellum-dependent swarming motility over surfaces. In liquid, P. mirabilis cells are 1.5- to 2.0-μm swimmer cells with 4 to 6 flagella. When P. mirabilis encounters a solid surface, where flagellar rotation is limited, swimmer cells differentiate into elongated (10- to 80-μm), highly flagellated swarmer cells. In order for P. mirabilis to swarm, it first needs to detect a surface. The ubiquitous but functionally enigmatic flagellar basal body protein FliL is involved in P. mirabilis surface sensing. Previous studies have suggested that FliL is essential for swarming through its involvement in viscosity-dependent monitoring of flagellar rotation. In this study, we constructed and characterized ΔfliL mutants of P. mirabilis and Escherichia coli. Unexpectedly and unlike other fliL mutants, both P. mirabilis and E. coli ΔfliL cells swarm (Swr(+)). Further analysis revealed that P. mirabilis ΔfliL cells also exhibit an alteration in their ability to sense a surface: e.g., ΔfliL P. mirabilis cells swarm precociously over surfaces with low viscosity that normally impede wild-type swarming. Precocious swarming is due to an increase in the number of elongated swarmer cells in the population. Loss of fliL also results in an inhibition of swarming at <30°C. E. coli ΔfliL cells also exhibit temperature-sensitive swarming. These results suggest an involvement of FliL in the energetics and function of the flagellar motor. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. The effect of induction motor shaft diameter on motor performance

    Directory of Open Access Journals (Sweden)

    Asım Gökhan Yetgin

    2017-10-01

    Full Text Available Induction motors are used in many areas from the past to the present and in different fields with the development of technology has continued to be used. It is obvious that induction motors as an improvement to the efficiency in terms of energy saving would cause great benefit. In that context, induction motor manufacturers and designers are constantly trying out new methods to improve motor performance and efficiency. In this study, what would be the optimum diameter of the shaft in order to increase the efficiency of the induction motor were investigated. In the study, 5.5 kW, 7.5 kW and 11 kW motors analyzes were also performed. Obtained shaft diameter values were compared with the manufacturer values. In addition, critical points such as the magnetic flux values, weight values and performances of the motors were examined and optimal shaft diameter values for each motor have been determined.

  17. The impact of family intactness on family functioning, parental control and parent-child relational qualities in a Chinese context

    Directory of Open Access Journals (Sweden)

    Daniel Tan Lei Shek

    2015-01-01

    Full Text Available The current study investigated the differences between intact and non-intact families in family processes, including systematic family functioning, parental behavioral control, parental psychological control, and parent-child relational qualities. The participants were 3,328 Secondary One students, with a mean age of 12.59 years, recruited from 28 secondary schools in Hong Kong. Four validated scales were used to assess family processes. Results showed that adolescents in non-intact families perceived relatively poorer family functioning, lower level of paternal and maternal behavioral control, lower level of paternal psychological control and poorer parent-child relational qualities than did adolescents in intact families. This generally indicated that family processes were poorer in non-intact families, compared with those in intact families. The theoretical and practical implications of the findings were discussed.

  18. Motor experience with a sport-specific implement affects motor imagery

    Science.gov (United States)

    Zhu, Hua; Shen, Cheng; Zhang, Jian

    2018-01-01

    The present study tested whether sport-specific implements facilitate motor imagery, whereas nonspecific implements disrupt motor imagery. We asked a group of basketball players (experts) and a group of healthy controls (novices) to physically perform (motor execution) and mentally simulate (motor imagery) basketball throws. Subjects produced motor imagery when they were holding a basketball, a volleyball, or nothing. Motor imagery performance was measured by temporal congruence, which is the correspondence between imagery and execution times estimated as (imagery time minus execution time) divided by (imagery time plus execution time), as well as the vividness of motor imagery. Results showed that experts produced greater temporal congruence and vividness of kinesthetic imagery while holding a basketball compared to when they were holding nothing, suggesting a facilitation effect from sport-specific implements. In contrast, experts produced lower temporal congruence and vividness of kinesthetic imagery while holding a volleyball compared to when they were holding nothing, suggesting the interference effect of nonspecific implements. Furthermore, we found a negative correlation between temporal congruence and the vividness of kinesthetic imagery in experts while holding a basketball. On the contrary, the implement manipulation did not modulate the temporal congruence of novices. Our findings suggest that motor representation in experts is built on motor experience associated with specific-implement use and thus was subjected to modulation of the implement held. We conclude that sport-specific implements facilitate motor imagery, whereas nonspecific implements could disrupt motor representation in experts. PMID:29719738

  19. Peptidomics and Secretomics of the Mammalian Peripheral Sensory-Motor System

    Science.gov (United States)

    Tillmaand, Emily G.; Yang, Ning; Kindt, Callie A. C.; Romanova, Elena V.; Rubakhin, Stanislav S.; Sweedler, Jonathan V.

    2015-12-01

    The dorsal root ganglion (DRG) and its anatomically and functionally associated spinal nerve and ventral and dorsal roots are important components of the peripheral sensory-motor system in mammals. The cells within these structures use a number of peptides as intercellular signaling molecules. We performed a variety of mass spectrometry (MS)-based characterizations of peptides contained within and secreted from these structures, and from isolated and cultured DRG cells. Liquid chromatography-Fourier transform MS was utilized in DRG and nerve peptidome analysis. In total, 2724 peptides from 296 proteins were identified in tissue extracts. Neuropeptides are among those detected, including calcitonin gene-related peptide I, little SAAS, and known hemoglobin-derived peptides. Solid phase extraction combined with direct matrix-assisted laser desorption/ionization time-of-flight MS was employed to investigate the secretome of these structures. A number of peptides were detected in the releasate from semi-intact preparations of DRGs and associated nerves, including neurofilament- and myelin basic protein-related peptides. A smaller set of analytes was observed in releasates from cultured DRG neurons. The peptide signals observed in the releasates have been mass-matched to those characterized and identified in homogenates of entire DRGs and associated nerves. This data aids our understanding of the chemical composition of the mammalian peripheral sensory-motor system, which is involved in key physiological functions such as nociception, thermoreception, itch sensation, and proprioception.

  20. A positive association between active lifestyle and hemispheric lateralization for motor control and learning in older adults.

    Science.gov (United States)

    Wang, Jinsung; D'Amato, Arthur; Bambrough, Jennifer; Swartz, Ann M; Miller, Nora E

    2016-11-01

    Physical activity (PA) is well known to have general health benefits for older adults, but it is unclear whether it can also positively affect brain function involved in motor control and learning. We have previously shown that interlimb transfer of visuomotor adaptation occurs asymmetrically in young adults, while that occurs symmetrically in older adults, which suggests that the lateralized function of each hemisphere during motor tasks is diminished with aging. Here, we investigated the association between the level of PA and hemispheric motor lateralization by comparing the pattern of interlimb transfer following visuomotor adaptation between physically active and inactive older adults. Subjects were divided into two groups based on their PA level (active, inactive). They were further divided into two groups, such that a half of the subjects in each group adapted to a 30° rotation during targeted reaching movements with the left arm first, then with the right arm; and the other half with the right arm first, then with the left arm. Results indicated asymmetrical transfer (from left to right only) in the active subjects, whereas symmetrical transfer (from left to right, and vice versa) was observed in the inactive subjects. These findings suggest that older adults who maintain active lifestyle have a central nervous system that is more intact in terms of its lateralized motor function as compared with those who are inactive. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Motor-operated valve (MOV) actuator motor and gearbox testing

    International Nuclear Information System (INIS)

    DeWall, K.; Watkins, J.C.; Bramwell, D.

    1997-07-01

    Researchers at the Idaho National Engineering and Environmental Laboratory tested the performance of electric motors and actuator gearboxes typical of the equipment installed on motor-operated valves used in nuclear power plants. Using a test stand that simulates valve closure loads against flow and pressure, the authors tested five electric motors (four ac and one dc) and three gearboxes at conditions a motor might experience in a power plant, including such off-normal conditions as operation at high temperature and reduced voltage. They also monitored the efficiency of the actuator gearbox. All five motors operated at or above their rated starting torque during tests at normal voltages and temperatures. For all five motors, actual torque losses due to voltage degradation were greater than the losses calculated by methods typically used for predicting motor torque at degraded voltage conditions. For the dc motor the actual torque losses due to elevated operating temperatures were greater than the losses calculated by the typical predictive method. The actual efficiencies of the actuator gearboxes were generally lower than the running efficiencies published by the manufacturer and were generally nearer the published pull-out efficiencies. Operation of the gearbox at elevated temperature did not affect the operating efficiency

  2. The change in perceived motor competence and motor task values during elementary school : Gender and motor performance differences

    NARCIS (Netherlands)

    Noordstar, J.J.; van der Net, J.; Jak, S.; Helders, P.J.M.; Jongmans, M.J.

    2016-01-01

    Participation in motor activities is essential for social interaction and life satisfaction in children. Self-perceptions and task values have a central position in why children do or do not participate in (motor) activities. Investigating developmental changes in motor self-perceptions and motor

  3. Global forest loss disproportionately erodes biodiversity in intact landscapes.

    Science.gov (United States)

    Betts, Matthew G; Wolf, Christopher; Ripple, William J; Phalan, Ben; Millers, Kimberley A; Duarte, Adam; Butchart, Stuart H M; Levi, Taal

    2017-07-27

    Global biodiversity loss is a critical environmental crisis, yet the lack of spatial data on biodiversity threats has hindered conservation strategies. Theory predicts that abrupt biodiversity declines are most likely to occur when habitat availability is reduced to very low levels in the landscape (10-30%). Alternatively, recent evidence indicates that biodiversity is best conserved by minimizing human intrusion into intact and relatively unfragmented landscapes. Here we use recently available forest loss data to test deforestation effects on International Union for Conservation of Nature Red List categories of extinction risk for 19,432 vertebrate species worldwide. As expected, deforestation substantially increased the odds of a species being listed as threatened, undergoing recent upgrading to a higher threat category and exhibiting declining populations. More importantly, we show that these risks were disproportionately high in relatively intact landscapes; even minimal deforestation has had severe consequences for vertebrate biodiversity. We found little support for the alternative hypothesis that forest loss is most detrimental in already fragmented landscapes. Spatial analysis revealed high-risk hot spots in Borneo, the central Amazon and the Congo Basin. In these regions, our model predicts that 121-219 species will become threatened under current rates of forest loss over the next 30 years. Given that only 17.9% of these high-risk areas are formally protected and only 8.9% have strict protection, new large-scale conservation efforts to protect intact forests are necessary to slow deforestation rates and to avert a new wave of global extinctions.

  4. Electric motor handbook

    CERN Document Server

    Chalmers, B J

    2013-01-01

    Electric Motor Handbook aims to give practical knowledge in a wide range of capacities such as plant design, equipment specification, commissioning, operation and maintenance. The book covers topics such as the modeling of steady-state motor performance; polyphase induction, synchronous, and a.c. commutator motors; ambient conditions, enclosures, cooling and loss dissipation; and electrical supply systems and motor drives. Also covered are topics such as variable-speed drives and motor control; materials and motor components; insulation types, systems, and techniques; and the installation, sit

  5. Coupling with concentric contact around motor shaft for line start synchronous motor

    Science.gov (United States)

    Melfi, Michael J.; Burdeshaw, Galen E.

    2017-10-03

    A method comprises providing a line-start synchronous motor. The motor has a stator, a rotor core disposed within the stator, and a motor shaft. In accordance with a step of the method, a coupling for coupling a load to the motor is provided. The coupling has a motor shaft attachment portion configured to provide substantially concentric contact around the shaft at the end of the motor shaft. The coupling has a load attachment portion configured to operatively connect to a load. In accordance with a step of the method, a load is coupled to the motor with the coupling, and driven from start to at least near synchronous speed during steady state operation of the motor with a load coupled thereto. The motor shaft attachment portion may comprise a bushing assembly with matching and opposed tapered surfaces that cooperate to secure the motor shaft attachment portion around the motor shaft.

  6. Concurrent word generation and motor performance: further evidence for language-motor interaction.

    Directory of Open Access Journals (Sweden)

    Amy D Rodriguez

    Full Text Available Embodied/modality-specific theories of semantic memory propose that sensorimotor representations play an important role in perception and action. A large body of evidence supports the notion that concepts involving human motor action (i.e., semantic-motor representations are processed in both language and motor regions of the brain. However, most studies have focused on perceptual tasks, leaving unanswered questions about language-motor interaction during production tasks. Thus, we investigated the effects of shared semantic-motor representations on concurrent language and motor production tasks in healthy young adults, manipulating the semantic task (motor-related vs. nonmotor-related words and the motor task (i.e., standing still and finger-tapping. In Experiment 1 (n = 20, we demonstrated that motor-related word generation was sufficient to affect postural control. In Experiment 2 (n = 40, we demonstrated that motor-related word generation was sufficient to facilitate word generation and finger tapping. We conclude that engaging semantic-motor representations can have a reciprocal influence on motor and language production. Our study provides additional support for functional language-motor interaction, as well as embodied/modality-specific theories.

  7. A novel flagellar sheath protein, FcpA, determines filament coiling, translational motility and virulence for the Leptospira spirochete.

    Science.gov (United States)

    Wunder, Elsio A; Figueira, Cláudio P; Benaroudj, Nadia; Hu, Bo; Tong, Brian A; Trajtenberg, Felipe; Liu, Jun; Reis, Mitermayer G; Charon, Nyles W; Buschiazzo, Alejandro; Picardeau, Mathieu; Ko, Albert I

    2016-08-01

    Leptospira are unique among bacteria based on their helical cell morphology with hook-shaped ends and the presence of periplasmic flagella (PF) with pronounced spontaneous supercoiling. The factors that provoke such supercoiling, as well as the role that PF coiling plays in generating the characteristic hook-end cell morphology and motility, have not been elucidated. We have now identified an abundant protein from the pathogen L. interrogans, exposed on the PF surface, and named it Flagellar-coiling protein A (FcpA). The gene encoding FcpA is highly conserved among Leptospira and was not found in other bacteria. fcpA(-) mutants, obtained from clinical isolates or by allelic exchange, had relatively straight, smaller-diameter PF, and were not able to produce translational motility. These mutants lost their ability to cause disease in the standard hamster model of leptospirosis. Complementation of fcpA restored the wild-type morphology, motility and virulence phenotypes. In summary, we identified a novel Leptospira 36-kDa protein, the main component of the spirochete's PF sheath, and a key determinant of the flagella's coiled structure. FcpA is essential for bacterial translational motility and to enable the spirochete to penetrate the host, traverse tissue barriers, disseminate to cause systemic infection and reach target organs. © 2016 John Wiley & Sons Ltd.

  8. Plasmid AZOBR_p1-borne fabG gene for putative 3-oxoacyl-[acyl-carrier protein] reductase is essential for proper assembly and work of the dual flagellar system in the alphaproteobacterium Azospirillum brasilense Sp245.

    Science.gov (United States)

    Filip'echeva, Yulia A; Shelud'ko, Andrei V; Prilipov, Alexei G; Burygin, Gennady L; Telesheva, Elizaveta M; Yevstigneyeva, Stella S; Chernyshova, Marina P; Petrova, Lilia P; Katsy, Elena I

    2018-02-01

    Azospirillum brasilense can swim and swarm owing to the activity of a constitutive polar flagellum (Fla) and inducible lateral flagella (Laf), respectively. Experimental data on the regulation of the Fla and Laf assembly in azospirilla are scarce. Here, the coding sequence (CDS) AZOBR_p1160043 (fabG1) for a putative 3-oxoacyl-[acyl-carrier protein (ACP)] reductase was found essential for the construction of both types of flagella. In an immotile leaky Fla - Laf - fabG1::Omegon-Km mutant, Sp245.1610, defects in flagellation and motility were fully complemented by expressing the CDS AZOBR_p1160043 from plasmid pRK415. When pRK415 with the cloned CDS AZOBR_p1160045 (fliC) for a putative 65.2 kDa Sp245 Fla flagellin was transferred into the Sp245.1610 cells, the bacteria also became able to assemble a motile single flagellum. Some cells, however, had unusual swimming behavior, probably because of the side location of the organelle. Although the assembly of Laf was not restored in Sp245.1610 (pRK415-p1160045), this strain was somewhat capable of swarming motility. We propose that the putative 3-oxoacyl-[ACP] reductase encoded by the CDS AZOBR_p1160043 plays a role in correct flagellar location in the cell envelope and (or) in flagellar modification(s), which are also required for the inducible construction of Laf and for proper swimming and swarming motility of A. brasilense Sp245.

  9. Motor cortex is required for learning but not executing a motor skill

    Science.gov (United States)

    Kawai, Risa; Markman, Timothy; Poddar, Rajesh; Ko, Raymond; Fantana, Antoniu; Dhawale, Ashesh; Kampff, Adam R.; Ölveczky, Bence P.

    2018-01-01

    Motor cortex is widely believed to underlie the acquisition and execution of motor skills, yet its contributions to these processes are not fully understood. One reason is that studies on motor skills often conflate motor cortex’s established role in dexterous control with roles in learning and producing task-specific motor sequences. To dissociate these aspects, we developed a motor task for rats that trains spatiotemporally precise movement patterns without requirements for dexterity. Remarkably, motor cortex lesions had no discernible effect on the acquired skills, which were expressed in their distinct pre-lesion forms on the very first day of post-lesion training. Motor cortex lesions prior to training, however, rendered rats unable to acquire the stereotyped motor sequences required for the task. These results suggest a remarkable capacity of subcortical motor circuits to execute learned skills and a previously unappreciated role for motor cortex in ‘tutoring’ these circuits during learning. PMID:25892304

  10. Superolateral Dislocation of Intact Mandibular Condyle: A Case Report and Review of Literature

    OpenAIRE

    Saikrishna, Degala; Shyam Sundar, S.; Mamata, K. S.

    2015-01-01

    Anteromedial fracture dislocation of the mandibular condyle is common but a superolateral dislocation of an intact condyle is quite rare. This type of dislocation is often misdiagnosed or completely overlooked and hence inadequately addressed. We report a case of a 41-year-old male patient who experienced superolateral dislocation of the intact condyle with symphysis fracture and panfacial fracture following a road-traffic accident, and review of literature of superolateral dislocations from ...

  11. Prediction of valid acidity in intact apples with Fourier transform near infrared spectroscopy*

    OpenAIRE

    Liu, Yan-de; Ying, Yi-bin; Fu, Xia-ping

    2005-01-01

    To develop nondestructive acidity prediction for intact Fuji apples, the potential of Fourier transform near infrared (FT-NIR) method with fiber optics in interactance mode was investigated. Interactance in the 800 nm to 2619 nm region was measured for intact apples, harvested from early to late maturity stages. Spectral data were analyzed by two multivariate calibration techniques including partial least squares (PLS) and principal component regression (PCR) methods. A total of 120 Fuji appl...

  12. Conceptual design of stepper motor replacing servo motor for control rod controller

    International Nuclear Information System (INIS)

    Mohd Dzul Aiman Aslan; Mohd Idris Taib; Izhar Abu Hussin; Mohd Khairulezwan Abdul Manan; Mohd Sabri Minhat

    2010-01-01

    In PUSPATI TRIGA Reactor, current control rod controller are using servo motor to control the movement. Control rod is a very important safety element and measure in every nuclear reactor. So, precision is very important in measurement of security in the nuclear reactor. In this case, there are a few disadvantages when using the servo motor is measurement of the motor is not precise. One solution to overcome this is by shifting servo motor with stepper motor. A stepper motor (or step motor) is a brush less, synchronous electric motor that can divide a full rotation into a large number of steps. (author)

  13. A versatile stepping motor controller for systems with many motors

    International Nuclear Information System (INIS)

    Feng, S.K.; Siddons, D.P.

    1989-01-01

    A versatile system for controlling beamlines or complex experimental setups is described. The system as currently configured can control up to 32 motors, with all motors capable of full speed operation concurrently. There are 2 limit switch inputs for each motor, and a further input to accept a reference position marker. The motors can be controlled via a front panel keyboard with display, or by a host computer over an IEEE-488 interface. Both methods can be used together if required. There is an ''emergency stop'' key on the front panel keyboard to stop the motion of all motors without losing track of the motors' position. 3 refs., 4 figs., 1 tab

  14. HTSL massive motor. Project: Motor field calculation. Final report

    International Nuclear Information System (INIS)

    Gutt, H.J.; Gruener, A.

    2003-01-01

    HTS motors up to 300 kW were to be developed and optimized. For this, specific calculation methods were enhanced to include superconducting rotor types (hysteresis, reluctance and permanent magnet HTS rotors). The experiments were carried out in a SHM70-45 hysteresis motor. It was shown how static and dynamic trapped field magnetisation of the rotor with YBCO rings will increase flux in the air gap motor, increasing the motor capacity to twice its original level. (orig.) [de

  15. Multi-Axis Prosthetic Knee Resembles Alpine Skiing Movements of an Intact Leg

    Directory of Open Access Journals (Sweden)

    Ivan Demšar, Jože Duhovnik, Blaž Lešnik, Matej Supej

    2015-12-01

    Full Text Available The purpose of the study was to analyse the flexion angles of the ski boot, ankle and knee joints of an above-knee prosthesis and to compare them with an intact leg and a control group of skiers. One subject with an above-knee amputation of the right leg and eight healthy subjects simulated the movement of a skiing turn by performing two-leg squats in laboratory conditions. By adding additional loads in proportion to body weight (BW; +1/3 BW, +2/3 BW, +3/3 BW, various skiing regimes were simulated. Change of Flexion Angle (CoFA and Range of Motion (RoM in the ski boot, ankle and knee joints were calculated and compared. An average RoM in the skiing boot on the side of prosthesis (4.4 ± 1.1° was significantly lower compared to an intact leg (5.9 ± 1.8° and the control group (6.5 ± 2.3°. In the ankle joint, the average RoM was determined to be 13.2±2.9° in the prosthesis, 12.7 ± 2.8° in an intact leg and 14.8±3.6 in the control group. However, the RoM of the knee joint in the prosthesis (42.2 ± 4.2° was significantly larger than that of the intact leg (34.7 ± 4.4°. The average RoM of the knee joint in the control group was 47.8 ± 5.4°. The influences of additional loads on the kinematics of the lower extremities were different on the side of the prosthesis and on the intact leg. In contrast, additional loads did not produce any significant differences in the control group. Although different CoFAs in the ski boot, ankle and knee joints were used, an above-knee prosthesis with a built-in multi-axis prosthetic knee enables comparable leg kinematics in simulated alpine skiing.

  16. Handbook on linear motor application

    International Nuclear Information System (INIS)

    1988-10-01

    This book guides the application for Linear motor. It lists classification and speciality of Linear Motor, terms of linear-induction motor, principle of the Motor, types on one-side linear-induction motor, bilateral linear-induction motor, linear-DC Motor on basic of the motor, linear-DC Motor for moving-coil type, linear-DC motor for permanent-magnet moving type, linear-DC motor for electricity non-utility type, linear-pulse motor for variable motor, linear-pulse motor for permanent magneto type, linear-vibration actuator, linear-vibration actuator for moving-coil type, linear synchronous motor, linear electromagnetic motor, linear electromagnetic solenoid, technical organization and magnetic levitation and linear motor and sensor.

  17. DEVELOPMENT OF FINE MOTOR COORDINATION AND VISUAL-MOTOR INTEGRATION IN PRESCHOOL CHILDREN

    Directory of Open Access Journals (Sweden)

    Haris MEMISEVIC

    2013-03-01

    Full Text Available Fine motor skills are prerequisite for many everyday activities and they are a good predictor of a child's later academic outcome. The goal of the present study was to assess the effects of age on the development of fine motor coordination and visual-motor integration in preschool children. The sample for this study consisted of 276 preschool children from Canton Sara­jevo, Bosnia and Herzegovina. We assessed children's motor skills with Beery Visual Motor Integration Test and Lafayette Pegboard Test. Data were analyzed with one-way ANOVA, followed by planned com­parisons between the age groups. We also performed a regression analysis to assess the influence of age and motor coordination on visual-motor integration. The results showed that age has a great effect on the development of fine motor skills. Furthermore, the results indicated that there are possible sensitive periods at preschool age in which the development of fine motor skills is accelerated. Early intervention specialists should make a thorough evaluations of fine motor skills in preschool children and make motor (rehabilitation programs for children at risk of fine motor delays.

  18. Visual Speech Fills in Both Discrimination and Identification of Non-Intact Auditory Speech in Children

    Science.gov (United States)

    Jerger, Susan; Damian, Markus F.; McAlpine, Rachel P.; Abdi, Herve

    2018-01-01

    To communicate, children must discriminate and identify speech sounds. Because visual speech plays an important role in this process, we explored how visual speech influences phoneme discrimination and identification by children. Critical items had intact visual speech (e.g. baez) coupled to non-intact (excised onsets) auditory speech (signified…

  19. 41 CFR 102-34.85 - What motor vehicles require motor vehicle identification?

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What motor vehicles require motor vehicle identification? 102-34.85 Section 102-34.85 Public Contracts and Property Management... 34-MOTOR VEHICLE MANAGEMENT Identifying and Registering Motor Vehicles Motor Vehicle Identification...

  20. DC Motor control using motor-generator set with controlled generator field

    Science.gov (United States)

    Belsterling, Charles A.; Stone, John

    1982-01-01

    A d.c. generator is connected in series opposed to the polarity of a d.c. power source supplying a d.c. drive motor. The generator is part of a motor-generator set, the motor of which is supplied from the power source connected to the motor. A generator field control means varies the field produced by at least one of the generator windings in order to change the effective voltage output. When the generator voltage is exactly equal to the d.c. voltage supply, no voltage is applied across the drive motor. As the field of the generator is reduced, the drive motor is supplied greater voltage until the full voltage of the d.c. power source is supplied when the generator has zero field applied. Additional voltage may be applied across the drive motor by reversing and increasing the reversed field on the generator. The drive motor may be reversed in direction from standstill by increasing the generator field so that a reverse voltage is applied across the d.c. motor.

  1. Two-day fasting evokes stress, but does not affect mood, brain activity, cognitive, psychomotor, and motor performance in overweight women.

    Science.gov (United States)

    Solianik, Rima; Sujeta, Artūras

    2018-02-15

    The physiological, cognitive state, and motor behavior changes that occur during acute fasting are not completely understood. Thus, the aim of this study was to estimate the effect of 2-day total fasting on evoked stress, mood, brain activity, and cognitive, psychomotor, and motor function in overweight women. Eleven overweight women (body mass index above 25kg/m 2 ) aged 20-30 years were tested under two conditions allocated randomly: 2-day zero-calorie diet with water provided ad libitum and 2-day usual diet. One week before the experiment, aerobic fitness was evaluated. Subjective stress ratings in relation to the diet, autonomic function, prefrontal cortex activity, cognitive performance, psychomotor coordination, and grip strength were evaluated before and after each diet. The study demonstrated that fasting decreased log-transformed high-frequency (HF) power, without affecting heart rate. The relative maximum oxygen uptake was negatively correlated with subjective stress rating and changes in log-transformed HF. Fasting did not affect mood, brain activity, and cognitive, motor, and psychomotor performance. Thus, 2-day total fasting evoked moderate stress with a shift of the autonomic nervous system balance toward sympathetic activity in overweight women. Better aerobic endurance is likely to facilitate the capacity for dealing with acute fasting. Regardless of the evoked stress, cognitive state and motor behavior remained intact. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Motor performance is impaired following vestibular stimulation in ageing mice.

    Directory of Open Access Journals (Sweden)

    Victoria W.K. Tung

    2016-02-01

    Full Text Available Balance and maintaining postural equilibrium are important during stationary and dynamic movements to prevent falls, particularly in older adults. While our sense of balance is influenced by vestibular, proprioceptive, and visual information, this study focuses primarily on the vestibular component and its age-related effects on balance. C57Bl/6J mice of ages 1, 5-6, 8-9 and 27-28 months were tested using a combination of standard (such as grip strength and rotarod and newly-developed behavioural tests (including balance beam and walking trajectory tests with a vestibular stimulus. In the current study, we confirm a decline in fore-limb grip strength and gross motor coordination as age increases. We also show that a vestibular stimulus of low frequency (2-3 Hz and duration can lead to age-dependent changes in balance beam performance, which was evident by increases in latency to begin walking on the beam as well as the number of times hind-feet slip from the beam. Furthermore, aged mice (27-28 months that received continuous access to a running wheel for 4 weeks did not improve when retested. Mice of ages 1, 10, 13, and 27-28 months were also tested for changes in walking trajectory as a result of the vestibular stimulus. While no linear relationship was observed between the changes in trajectory and age, 1-month-old mice were considerably less affected than mice of ages 10, 13, and 27-28 months. Conclusion: This study confirms there are age-related declines in grip strength and gross motor coordination. We also demonstrate age-dependent changes to finer motor abilities as a result of a low frequency and duration vestibular stimulus. These changes showed that while the ability to perform the balance beam task remained intact across all ages tested, behavioural changes in task performance were observed.

  3. Motor Performance is Impaired Following Vestibular Stimulation in Ageing Mice.

    Science.gov (United States)

    Tung, Victoria W K; Burton, Thomas J; Quail, Stephanie L; Mathews, Miranda A; Camp, Aaron J

    2016-01-01

    Balance and maintaining postural equilibrium are important during stationary and dynamic movements to prevent falls, particularly in older adults. While our sense of balance is influenced by vestibular, proprioceptive, and visual information, this study focuses primarily on the vestibular component and its age-related effects on balance. C57Bl/6J mice of ages 1, 5-6, 8-9 and 27-28 months were tested using a combination of standard (such as grip strength and rotarod) and newly-developed behavioral tests (including balance beam and walking trajectory tests with a vestibular stimulus). In the current study, we confirm a decline in fore-limb grip strength and gross motor coordination as age increases. We also show that a vestibular stimulus of low frequency (2-3 Hz) and duration can lead to age-dependent changes in balance beam performance, which was evident by increases in latency to begin walking on the beam as well as the number of times hind-feet slip (FS) from the beam. Furthermore, aged mice (27-28 months) that received continuous access to a running wheel for 4 weeks did not improve when retested. Mice of ages 1, 10, 13 and 27-28 months were also tested for changes in walking trajectory as a result of the vestibular stimulus. While no linear relationship was observed between the changes in trajectory and age, 1-month-old mice were considerably less affected than mice of ages 10, 13 and 27-28 months. this study confirms there are age-related declines in grip strength and gross motor coordination. We also demonstrate age-dependent changes to finer motor abilities as a result of a low frequency and duration vestibular stimulus. These changes showed that while the ability to perform the balance beam task remained intact across all ages tested, behavioral changes in task performance were observed.

  4. Intactness of cell wall structure controls the in vitro digestion of starch in legumes.

    Science.gov (United States)

    Dhital, Sushil; Bhattarai, Rewati R; Gorham, John; Gidley, Michael J

    2016-03-01

    Increasing the level of starch that is not digested by the end of the small intestine and therefore enters the colon ('resistant starch') is a major opportunity for improving the nutritional profile of foods. One mechanism that has been shown to be successful is entrapment of starch within an intact plant tissue structure. However, the level of tissue intactness required for resistance to amylase digestion has not been defined. In this study, intact cells were isolated from a range of legumes after thermal treatment at 60 °C (starch not gelatinised) or 95 °C (starch gelatinised) followed by hydrolysis using pancreatic alpha amylase. It was found that intact cells, isolated at either temperature, were impervious to amylase. However, application of mechanical force damaged the cell wall and made starch accessible to digestive enzymes. This shows that the access of enzymes to the entrapped swollen starch is the rate limiting step controlling hydrolysis of starch in cooked legumes. The results suggest that a single cell wall could be sufficient to provide an effective delivery of starch to the large intestine with consequent nutritional benefits, provided that mechanical damage during digestion is avoided.

  5. Differences in School Behavior and Achievement between Children from Intact, Reconstituted, and Single-Parent Families.

    Science.gov (United States)

    Featherstone, Darin R.; And Others

    1992-01-01

    Analyzed differences in school behavior and achievement among students (n=530) in grades six through nine from intact, reconstituted, and single-parent families. Students from intact, two-parent families had fewer absences and tardies, higher grade point averages, and fewer negative and more positive teacher behavioral ratings than did those from…

  6. [CHANGE OF CHARACTER OF INTERSYSTEMIC INTERACTIONS IN NEWBORN RAT PUPS UNDER CONDITIONS OF A DECREASE OF MOTOR ACTIVITY].

    Science.gov (United States)

    Sizonov, V A; Dmitrieva, L E; Kuznetsov, S V

    2015-01-01

    Interaction of slow-wave.rhythmic components of cardiac, respiratory.and motor activity was investigated in newborn rat pups on the first day after birth under normal conditions and after pharmacological depression of spontaneous periodic motor activity (SPMA) produced by injecting myocuran (myanesin) at low (100 mg/pg, i/p) and maximal (235 mg/pg, i/p) dosages. The data obtained allow to infer that in rat pups after birth the intersystemic interactions are realized mainly via slow-wave oscillations of about-one- and many-minute ranges whereas the rhythms of decasecond range do not play a significant role in integrative processes. Injection of miocuran at a dose causing no muscle relaxation and no inhibition of motor activity produces changes of the cardiac and respiratory rhythms as well as a transitory decrease of the magnitude of coordinate relations mediated by the rhythms of about-one- and many-minute ranges. The consequences of muscle relaxant injection were found to be more significant for intersystemic interactions with participation of the respiratory system. An increase of the dosage and, correspondingly, the total inhibition of SPMA is accompanied by reduction of the slow-wave components from the pattern of cardiac and respiratory rhythms. The cardiorespiratory interactions, more expressed in intact rat pups, are reduced in the about-one- and many-minute ranges of modulation whereas in the decasecond range of modulation they are slightly increased. Key words: early ontogenesis, intersystemic interactions, cardiac rhythm, respiration, motor activity, myocuran (myanesin).

  7. Non-motor and motor features in LRRK2 transgenic mice.

    Directory of Open Access Journals (Sweden)

    Zoë Bichler

    Full Text Available Non-motor symptoms are increasingly recognized as important features of Parkinson's disease (PD. LRRK2 mutations are common causes of familial and sporadic PD. Non-motor features have not been yet comprehensively evaluated in LRRK2 transgenic mouse models.Using a transgenic mouse model overexpressing the R1441G mutation of the human LRRK2 gene, we have investigated the longitudinal correlation between motor and non-motor symptoms and determined if specific non-motor phenotypes precede motor symptoms.We investigated the onset of motor and non-motor phenotypes on the LRRK2(R1441G BAC transgenic mice and their littermate controls from 4 to 21 month-old using a battery of behavioral tests. The transgenic mutant mice displayed mild hypokinesia in the open field from 16 months old, with gastrointestinal dysfunctions beginning at 6 months old. Non-motor features such as depression and anxiety-like behaviors, sensorial functions (pain sensitivity and olfaction, and learning and memory abilities in the passive avoidance test were similar in the transgenic animals compared to littermate controls.LRRK2(R1441G BAC transgenic mice displayed gastrointestinal dysfunction at an early stage but did not have abnormalities in fine behaviors, olfaction, pain sensitivity, mood disorders and learning and memory compared to non-transgenic littermate controls. The observations on olfaction and gastrointestinal dysfunction in this model validate findings in human carriers. These mice did recapitulate mild Parkinsonian motor features at late stages but compensatory mechanisms modulating the progression of PD in these models should be further evaluated.

  8. Binding of radiolabelled luteinizing hormone to intact and ovariectomised rat uterus

    International Nuclear Information System (INIS)

    Sen, S.; Bhattacharya, S.

    1992-01-01

    Binding of ovine LH to uterine tissue preparation from intact and ovariectomised rat clearly indicates that uterus possesses specific binding sites for LH. Binding characteristics of LH to uterine tissue preparation from intact rat showed saturability with high affinity and low capacity. Scatchard plot analysis showed dissociation constant of the specific binding site to be 0.12 x 10 -9 mol/l and the number of binding sites was 2.31±0.05 fmol/mg protein. Ovariectomy did not change the binding affinity but effected a decrease in the number of binding sites (1.7 ± 0.08 f mol/mg protein). LH treatment of ovariectomized (ovx) rat had no effect on binding affinity but significantly increased the number of binding sites (3.23 ± 0.1 f mol/mg protein). Reduction of uterine weight due to ovariectomy and marked increase of ovx rat uterine weight by LH administration indicate a source of estrogen in ovx rat. An in vitro uterine tissue slice (from intact and ovx rat) incubation showed depletion of 17 β-estradiol (E 2 ) content in ovx rat which significantly elevated on LH addition. Data suggest the LH binding to rat uterine tissue has biological relevance. (author). 16 refs., 4 figs. 1 tab

  9. FUZZY LOGIC CONTROL OF ELECTRIC MOTORS AND MOTOR DRIVES: FEASIBILITY STUDY

    Science.gov (United States)

    The report gives results of a study (part 1) of fuzzy logic motor control (FLMC). The study included: 1) reviews of existing applications of fuzzy logic, of motor operation, and of motor control; 2) a description of motor control schemes that can utilize FLMC; 3) selection of a m...

  10. Motor-pump unit provided with a lifting appliance of the motor

    International Nuclear Information System (INIS)

    Veronesi, Luciano; Francis, W.R.

    1978-01-01

    This invention relates to lifting appliances and particularly concerns a 'pump and motor set' or motor-pump unit fitted with a lifting appliance enabling the motor to be separated from the pump. In nuclear power stations the reactor discharges heat that is carried by the coolant to a distant point away from the reactor to generate steam and electricity conventionally. In order to cause the reactor coolant to flow through the system, coolant motor-pump units are provided in the cooling system. These units are generally of the vertical type with an electric motor fitted vertically on the pump by means of a cylindrical or conical structure called motor support [fr

  11. Chemical and mechanical efficiencies of molecular motors and implications for motor mechanisms

    International Nuclear Information System (INIS)

    Wang Hongyun

    2005-01-01

    Molecular motors operate in an environment dominated by viscous friction and thermal fluctuations. The chemical reaction in a motor may produce an active force at the reaction site to directly move the motor forward. Alternatively a molecular motor may generate a unidirectional motion by rectifying thermal fluctuations using free energy barriers established in the chemical reaction. The reaction cycle has many occupancy states, each having a different effect on the motor motion. The average effect of the chemical reaction on the motor motion can be characterized by the motor potential profile. The biggest advantage of studying the motor potential profile is that it can be reconstructed from the time series of motor positions measured in single-molecule experiments. In this paper, we use the motor potential profile to express the Stokes efficiency as the product of the chemical efficiency and the mechanical efficiency. We show that both the chemical and mechanical efficiencies are bounded by 100% and, thus, are properly defined efficiencies. We discuss implications of high efficiencies for motor mechanisms: a mechanical efficiency close to 100% implies that the motor potential profile is close to a constant slope; a chemical efficiency close to 100% implies that (i) the chemical transitions are not slower than the mechanical motion and (ii) the equilibrium constant of each chemical transition is close to one

  12. Motor cortex is required for learning but not for executing a motor skill.

    Science.gov (United States)

    Kawai, Risa; Markman, Timothy; Poddar, Rajesh; Ko, Raymond; Fantana, Antoniu L; Dhawale, Ashesh K; Kampff, Adam R; Ölveczky, Bence P

    2015-05-06

    Motor cortex is widely believed to underlie the acquisition and execution of motor skills, but its contributions to these processes are not fully understood. One reason is that studies on motor skills often conflate motor cortex's established role in dexterous control with roles in learning and producing task-specific motor sequences. To dissociate these aspects, we developed a motor task for rats that trains spatiotemporally precise movement patterns without requirements for dexterity. Remarkably, motor cortex lesions had no discernible effect on the acquired skills, which were expressed in their distinct pre-lesion forms on the very first day of post-lesion training. Motor cortex lesions prior to training, however, rendered rats unable to acquire the stereotyped motor sequences required for the task. These results suggest a remarkable capacity of subcortical motor circuits to execute learned skills and a previously unappreciated role for motor cortex in "tutoring" these circuits during learning. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Modulation of motor performance and motor learning by transcranial direct current stimulation.

    Science.gov (United States)

    Reis, Janine; Fritsch, Brita

    2011-12-01

    Transcranial direct current stimulation (tDCS) has shown preliminary success in improving motor performance and motor learning in healthy individuals, and restitution of motor deficits in stroke patients. This brief review highlights some recent work. Within the past years, behavioural studies have confirmed and specified the timing and polarity specific effects of tDCS on motor skill learning and motor adaptation. There is strong evidence that timely co-application of (hand/arm) training and anodal tDCS to the contralateral M1 can improve motor learning. Improvements in motor function as measured by clinical scores have been described for combined tDCS and training in stroke patients. For this purpose, electrode montages have been modified with respect to interhemispheric imbalance after brain injury. Cathodal tDCS applied to the unlesioned M1 or bihemispheric M1 stimulation appears to be well tolerated and useful to induce improvements in motor function. Mechanistic studies in humans and animals are discussed with regard to physiological motor learning. tDCS is well tolerated, easy to use and capable of inducing lasting improvements in motor function. This method holds promise for the rehabilitation of motor disabilities, although acute studies in patients with brain injury are so far lacking.

  14. Risks for Conduct Disorder Symptoms Associated with Parental Alcoholism in Stepfather Families versus Intact Families from a Community Sample

    Science.gov (United States)

    Foley, Debra L.; Pickles, Andrew; Rutter, Michael; Gardner, Charles O.; Maes, Hermine H.; Silberg, Judy L.; Eaves, Lindon J.

    2004-01-01

    Background: It is not known if the prevalence of parental psychiatric disorders is higher in stepfather than intact families, or if parental alcoholism is differentially associated with risk for conduct disorder (CD) symptoms in stepfather families versus intact families. Method: The sample comprised 839 girls and 741 boys from 792 intact families…

  15. Behavior Management Style of Single Parents and Intact Families.

    Science.gov (United States)

    Smith, Douglas K.; And Others

    Studies examining the behavior management styles of parents as a function of family intactness and parent employment status are lacking. To assess parental style of behavior management, the Parental Management Questionnaire (PMQ) was completed by 1,957 parents of elementary school children (50% response rate). The PMQ is based on Aronfreed's…

  16. Fundamental motor skill proficiency is necessary for children's motor activity inclusion

    Directory of Open Access Journals (Sweden)

    José Angelo Barela

    2013-09-01

    Full Text Available Motor development is influenced by many factors such as practice and appropriate instruction, provided by teachers, even in preschool and elementary school. The goal of this paper was to discuss the misconception that maturation underlies children's motor skill development and to show that physical education, even in early years of our school system, is critical to promote proficiency and enrolment of children's in later motor activities. Motor skill development, as a curricular focus, has been marginalized in many of our physical education proposal and in doing so, we have not promote motor competence in our children who lack proficiency to engage and to participate in later motor activities such as sport-related or recreational.

  17. Skeletal maturation, fundamental motor skills and motor coordination in children 7-10 years.

    Science.gov (United States)

    Freitas, Duarte L; Lausen, Berthold; Maia, José António; Lefevre, Johan; Gouveia, Élvio Rúbio; Thomis, Martine; Antunes, António Manuel; Claessens, Albrecht L; Beunen, Gaston; Malina, Robert M

    2015-01-01

    Relationships between skeletal maturation and fundamental motor skills and gross motor coordination were evaluated in 429 children (213 boys and 216 girls) 7-10 years. Skeletal age was assessed (Tanner-Whitehouse 2 method), and stature, body mass, motor coordination (Körperkoordinations Test für Kinder, KTK) and fundamental motor skills (Test of Gross Motor Development, TGMD-2) were measured. Relationships among chronological age, skeletal age (expressed as the standardised residual of skeletal age on chronological age) and body size and fundamental motor skills and motor coordination were analysed with hierarchical multiple regression. Standardised residual of skeletal age on chronological age interacting with stature and body mass explained a maximum of 7.0% of the variance in fundamental motor skills and motor coordination over that attributed to body size per se. Standardised residual of skeletal age on chronological age alone accounted for a maximum of 9.0% of variance in fundamental motor skills, and motor coordination over that attributed to body size per se and interactions between standardised residual of skeletal age on chronological age and body size. In conclusion, skeletal age alone or interacting with body size has a negligible influence on fundamental motor skills and motor coordination in children 7-10 years.

  18. Neuroplasticity & Motor Learning

    DEFF Research Database (Denmark)

    Jensen, Jesper Lundbye

    Practice of a new motor task is usually associated with an improvement in performance. Indeed, if we stop practicing and return the next day to the same task, we find that our performance has been maintained and may even be better than it was at the start of the first day. This improvement...... is a measure of our ability to form and store a motor memory of the task. However, the initial memory of the task is labile and may be subject to interference. During and following motor learning plastic changes occur within the central nervous system. On one hand these changes are driven by motor practice......, on the other hand the changes underlie the formation of motor memory and the retention of improved motor performance. During motor learning changes may occur at many different levels within the central nervous system dependent on the type of task and training. Here, we demonstrate different studies from our...

  19. Quantitative proteomic analysis of intact plastids.

    Science.gov (United States)

    Shiraya, Takeshi; Kaneko, Kentaro; Mitsui, Toshiaki

    2014-01-01

    Plastids are specialized cell organelles in plant cells that are differentiated into various forms including chloroplasts, chromoplasts, and amyloplasts, and fulfill important functions in maintaining the overall cell metabolism and sensing environmental factors such as sunlight. It is therefore important to grasp the mechanisms of differentiation and functional changes of plastids in order to enhance the understanding of vegetality. In this chapter, details of a method for the extraction of intact plastids that makes analysis possible while maintaining the plastid functions are provided; in addition, a quantitative shotgun method for analyzing the composition and changes in the content of proteins in plastids as a result of environmental impacts is described.

  20. Comparison of allergenicity and immunogenicity of an intact allergen vaccine and commercially available allergoid products for birch pollen immunotherapy.

    Science.gov (United States)

    Lund, L; Henmar, H; Würtzen, P A; Lund, G; Hjortskov, N; Larsen, J N

    2007-04-01

    Specific immunotherapy with intact allergen vaccine is a well-documented treatment for allergic diseases. Different vaccine formulations are currently commercially available, the active ingredient either being intact allergens or chemically modified allergoids. The rationale behind allergoids is to decrease allergenicity while maintaining immunogenicity. However, data from the German health authorities based on reporting of adverse events over a 10-year period did not indicate increased safety of allergoids over intact allergens. The objective of this study was to investigate the effect of chemical modification on allergenicity and immunogenicity comparing four commercial allergoid products for birch pollen immunotherapy with an intact allergen vaccine. Solid-phase IgE inhibition and histamine release assays were selected as model systems for allergenicity, and a combination of human T cell proliferation and IgG titres following mouse immunizations were used to address the immunogenicity of the intact allergen vaccine and the four allergoids. In all assays, the products were normalized with respect to the manufacturer's recommended maintenance dose. IgE inhibition experiments showed a change in epitope composition comparing intact allergen vaccine with allergoid. One allergoid product induced enhanced histamine release compared to the intact allergens, while the other three allergoids showed reduced release. Standard T cell stimulation assays using lines from allergic patients showed a reduced response for all allergoids compared with the intact allergen vaccine regardless of the cell type used for antigen presentation. All allergoids showed reduced capacity to induce allergen-specific IgG responses in mice. While some allergoids were associated with reduced allergenicity, a clear reduction in immunogenicity was observed for all allergoid products compared with the intact allergen vaccine, and the commercial allergoids tested therefore do not fulfil the allergoid

  1. The Sensor Kinase GacS Negatively Regulates Flagellar Formation and Motility in a Biocontrol Bacterium, Pseudomonas chlororaphis O6

    Directory of Open Access Journals (Sweden)

    Ji Soo Kim

    2014-06-01

    Full Text Available The GacS/GacA two component system regulates various traits related to the biocontrol potential of plant-associated pseudomonads. The role of the sensor kinase, GacS, differs between strains in regulation of motility. In this study, we determined how a gacS mutation changed cell morphology and motility in Pseudomonas chlororaphis O6. The gacS mutant cells were elongated in stationary-phase compared to the wild type and the complemented gacS mutant, but cells did not differ in length in logarithmic phase. The gacS mutant had a two-fold increase in the number of flagella compared with the wild type strain; flagella number was restored to that of the wild type in the complemented gacS mutant. The more highly flagellated gacS mutant cells had greater swimming motilities than that of the wild type strain. Enhanced flagella formation in the gacS mutant correlated with increased expression of three genes, fleQ, fliQ and flhF, involved in flagellar formation. Expression of these genes in the complemented gacS mutant was similar to that of the wild type. These findings show that this root-colonizing pseudomonad adjusts flagella formation and cell morphology in stationary-phase using GacS as a major regulator.

  2. Raman spectroscopy of normal oral buccal mucosa tissues: study on intact and incised biopsies

    Science.gov (United States)

    Deshmukh, Atul; Singh, S. P.; Chaturvedi, Pankaj; Krishna, C. Murali

    2011-12-01

    Oral squamous cell carcinoma is one of among the top 10 malignancies. Optical spectroscopy, including Raman, is being actively pursued as alternative/adjunct for cancer diagnosis. Earlier studies have demonstrated the feasibility of classifying normal, premalignant, and malignant oral ex vivo tissues. Spectral features showed predominance of lipids and proteins in normal and cancer conditions, respectively, which were attributed to membrane lipids and surface proteins. In view of recent developments in deep tissue Raman spectroscopy, we have recorded Raman spectra from superior and inferior surfaces of 10 normal oral tissues on intact, as well as incised, biopsies after separation of epithelium from connective tissue. Spectral variations and similarities among different groups were explored by unsupervised (principal component analysis) and supervised (linear discriminant analysis, factorial discriminant analysis) methodologies. Clusters of spectra from superior and inferior surfaces of intact tissues show a high overlap; whereas spectra from separated epithelium and connective tissue sections yielded clear clusters, though they also overlap on clusters of intact tissues. Spectra of all four groups of normal tissues gave exclusive clusters when tested against malignant spectra. Thus, this study demonstrates that spectra recorded from the superior surface of an intact tissue may have contributions from deeper layers but has no bearing from the classification of a malignant tissues point of view.

  3. DC motors and servo-motors controlled by Raspberry Pi 2B

    Directory of Open Access Journals (Sweden)

    Šustek Michal

    2017-01-01

    Full Text Available The expanding capabilities of today’s microcontrollers and other devices lead to an increased utilization of these technologies in diverse fields. The automation and issue of remote control of moving objects belong to these fields. In this project, a microcontroller Raspberry Pi 2B was chosen for controlling DC motors and servo-motors. This paper provides basic insight into issue of controlling DC motors and servo-motors, connection between Raspberry and other components on breadboard and programming syntaxes for controlling motors in Python programming language.

  4. Secretion of intact proteins and peptide fragments by lysosomal pathways of protein degradation

    International Nuclear Information System (INIS)

    Isenman, L.D.; Dice, J.F.

    1989-01-01

    We report that degradation of proteins microinjected into human fibroblasts is accompanied by release into the culture medium of peptide fragments and intact proteins as well as single amino acids. For the nine proteins and polypeptides microinjected, acid-precipitable radioactivity, i.e. peptide fragments and/or intact proteins, ranged from 10 to 67% of the total released radioactivity. Peptide fragments and/or intact protein accounted for 60% of the radioactivity released into the medium by cells microinjected with ribonuclease A. Two major radiolabeled peptide fragments were found, and one was of an appropriate size to function as an antigen in antigen-presenting cells. The peptides released from microinjected ribonuclease A were derived from lysosomal pathways of proteolysis based on several lines of evidence. Previous studies have shown that microinjected ribonuclease A is degraded to single amino acids entirely within lysosomes. We show that release of free amino acids and peptide fragments and/or intact protein was equivalently stimulated by serum deprivation and equivalently inhibited by NH4Cl. We also show that lysosomal degradation of endocytosed [3H]ribonuclease A was accompanied by the release of two peptide fragments similar in size and charge to those from microinjected [ 3 H]ribonuclease A. These findings demonstrate that degradation within lysosomes occurs in a manner that spares specific peptides; they also suggest a previously unsuspected pathway by which cells can secrete cytosol-derived polypeptides

  5. Motor Skill Competence and Perceived Motor Competence: Which Best Predicts Physical Activity among Girls?

    Science.gov (United States)

    Khodaverdi, Zeinab; Bahram, Abbas; Khalaji, Hassan; Kazemnejad, Anoshirvan

    2013-10-01

    The main purpose of this study was to determine which correlate, perceived motor competence or motor skill competence, best predicts girls' physical activity behavior. A sample of 352 girls (mean age=8.7, SD=0.3 yr) participated in this study. To assess motor skill competence and perceived motor competence, each child completed the Test of Gross Motor Development-2 and Physical Ability sub-scale of Marsh's Self-Description Questionnaire. Children's physical activity was assessed by the Physical Activity Questionnaire for Older Children. Multiple linear regression model was used to determine whether perceived motor competence or motor skill competence best predicts moderate-to-vigorous self-report physical activity. Multiple regression analysis indicated that motor skill competence and perceived motor competence predicted 21% variance in physical activity (R(2)=0.21, F=48.9, P=0.001), and motor skill competence (R(2)=0.15, ᵝ=0.33, P= 0.001) resulted in more variance than perceived motor competence (R(2)=0.06, ᵝ=0.25, P=0.001) in physical activity. Results revealed motor skill competence had more influence in comparison with perceived motor competence on physical activity level. We suggest interventional programs based on motor skill competence and perceived motor competence should be administered or implemented to promote physical activity in young girls.

  6. 40 CFR 261.40 - Conditional Exclusion for Used, Intact Cathode Ray Tubes (CRTs) Exported for Recycling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Conditional Exclusion for Used, Intact Cathode Ray Tubes (CRTs) Exported for Recycling. 261.40 Section 261.40 Protection of Environment...) Exported for Recycling. Used, intact CRTs exported for recycling are not solid wastes if they meet the...

  7. Motor Cortex Activity During Functional Motor Skills: An fNIRS Study.

    Science.gov (United States)

    Nishiyori, Ryota; Bisconti, Silvia; Ulrich, Beverly

    2016-01-01

    Assessments of brain activity during motor task performance have been limited to fine motor movements due to technological constraints presented by traditional neuroimaging techniques, such as functional magnetic resonance imaging. Functional near-infrared spectroscopy (fNIRS) offers a promising method by which to overcome these constraints and investigate motor performance of functional motor tasks. The current study used fNIRS to quantify hemodynamic responses within the primary motor cortex in twelve healthy adults as they performed unimanual right, unimanual left, and bimanual reaching, and stepping in place. Results revealed that during both unimanual reaching tasks, the contralateral hemisphere showed significant activation in channels located approximately 3 cm medial to the C3 (for right-hand reach) and C4 (for left-hand reach) landmarks. Bimanual reaching and stepping showed activation in similar channels, which were located bilaterally across the primary motor cortex. The medial channels, surrounding Cz, showed significantly higher activations during stepping when compared to bimanual reaching. Our results extend the viability of fNIRS to study motor function and build a foundation for future investigation of motor development in infants during nascent functional behaviors and monitor how they may change with age or practice.

  8. Fine motor control

    Science.gov (United States)

    ... gross (large, general) motor control. An example of gross motor control is waving an arm in greeting. Problems ... out the child's developmental age. Children develop fine motor skills over time, by practicing and being taught. To ...

  9. Radioimmunolocalization and selective delivery of radiation in a rat model system: comparison of intact and fragmented antibody

    International Nuclear Information System (INIS)

    Walker, K.Z.; Seymour-Munn, K.; Axiak, S.M.; Raison, R.L.; Basten, A.; Towson, J.E.; Bautovitch, G.J.; Morris, J.

    1988-01-01

    Monoclonal antibody (MoAb) fragments are known to have advantages over intact immunoglobulins for radioimmunoscintigraphy. It is less clear whether they are as effective in the delivery of radioimmunotherapy. The imaging and dosimetric properties of an intact MoAb, K-1-21, reactive against human kappa light chains (LC) were compared with that of its F(ab') 2 and Fab fragments using a normal rat model system. Two days after injection of 131 I-K-1-21 into rats bearing antigen-sepharose implants, gamma camera images showed specific localization of the MoAb to the target (kappa LC) but not to the control (lambda LC) implant. Better images were obtained with K-1-21 F(ab') 2 than with Fab or intact antibody. Mean kappa implant: blood ratios were 8.6 ± 3.9 for Fab, 7.9 ± 1.8 for F(ab') 2 and 2.0 ± 0.3 for intact K-1-21. The improvement associated with the use of 131 I-K-1-21 fragments was, however, achieved at the expense of lower absolute values of activity at the target site. Thus the absorbed dose delivered to the implant by the intact K-1-21 was double that delivered with F(ab') 2 and six times that delivered with Fab. As intact K-1-21 also delivered a greater radiation dose to normal tissues, F(ab') 2 fragments may have the greatest overall advantages for therapy with radionuclide MoAb conjugates. (author)

  10. Gene Expression Changes in the Motor Cortex Mediating Motor Skill Learning

    Science.gov (United States)

    Cheung, Vincent C. K.; DeBoer, Caroline; Hanson, Elizabeth; Tunesi, Marta; D'Onofrio, Mara; Arisi, Ivan; Brandi, Rossella; Cattaneo, Antonino; Goosens, Ki A.

    2013-01-01

    The primary motor cortex (M1) supports motor skill learning, yet little is known about the genes that contribute to motor cortical plasticity. Such knowledge could identify candidate molecules whose targeting might enable a new understanding of motor cortical functions, and provide new drug targets for the treatment of diseases which impair motor function, such as ischemic stroke. Here, we assess changes in the motor-cortical transcriptome across different stages of motor skill acquisition. Adult rats were trained on a gradually acquired appetitive reach and grasp task that required different strategies for successful pellet retrieval, or a sham version of the task in which the rats received pellet reward without needing to develop the reach and grasp skill. Tissue was harvested from the forelimb motor-cortical area either before training commenced, prior to the initial rise in task performance, or at peak performance. Differential classes of gene expression were observed at the time point immediately preceding motor task improvement. Functional clustering revealed that gene expression changes were related to the synapse, development, intracellular signaling, and the fibroblast growth factor (FGF) family, with many modulated genes known to regulate synaptic plasticity, synaptogenesis, and cytoskeletal dynamics. The modulated expression of synaptic genes likely reflects ongoing network reorganization from commencement of training till the point of task improvement, suggesting that motor performance improves only after sufficient modifications in the cortical circuitry have accumulated. The regulated FGF-related genes may together contribute to M1 remodeling through their roles in synaptic growth and maturation. PMID:23637843

  11. Actions to promote energy efficient electric motors. Motors study group

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, A.T. de [Coimbra Univ. (PT). Inst. of Systems and Robotics (ISR)

    1996-10-01

    Motor electricity consumption is influenced by many factors including: motor efficiency, motor speed controls, power supply quality, harmonics, systems oversizing, distribution network, mechanical transmission system, maintenance practices, load management and cycling, and the efficiency of the end-use device (e.g. fan, pump, etc.). Due to their importance, an overview of these factors is presented in this report. This study also describes the electricity use in the industrial and tertiary sectors and the electricity consumption associated with the different types of electric motors systems in the Member States of the European Union, as well as estimated future evolution until 2010. The studies for individual countries were carried out by the different partners of the motors study group at a previous stage. The study has found that there is a lack of accurate information about the motor electricity consumption, installed motor capacity and the motor market in almost all the European Union countries and only some general statistical sources are available. There is little field data, which is mainly available in Denmark, France, Italy and the Netherlands. Due to this lack of primary information, some common assumptions were made, based on the experience of the members of the study group. This lack of end-use characterisation data shows the need for improvement from the point of view of current knowledge. It is therefore recommended that further research is undertaken to arrive at more accurate figures. These could be the basis for a better understanding for motor use in practice and - as a consequence - for a more precise appraisal of potentials and barriers to energy efficiency. (orig.)

  12. Het motorrijwiel : handboek voor motor- en scooterrijders, motor- en scootermonteurs en -technici

    NARCIS (Netherlands)

    Seyffardt, A.L.W.

    1961-01-01

    INHOUD: 1. De werking van de motor ; 2. De hoofddelen van de motor ; 3. De kleppen en de klepbeweging ; 4. Balancering, de meercilinder motor ; 5. Bijzonderheden over de werking ; 6. De carburateur ; 7. De smering van de motor ; 8. De tweetaktmotor ; 9. De elektrische installatie ; 10. De

  13. Efficacy of tricaine methanesulfonate (MS-222 as an anesthetic agent for blocking sensory-motor responses in Xenopus laevis tadpoles.

    Directory of Open Access Journals (Sweden)

    Carlana Ramlochansingh

    Full Text Available Anesthetics are drugs that reversibly relieve pain, decrease body movements and suppress neuronal activity. Most drugs only cover one of these effects; for instance, analgesics relieve pain but fail to block primary fiber responses to noxious stimuli. Alternately, paralytic drugs block synaptic transmission at neuromuscular junctions, thereby effectively paralyzing skeletal muscles. Thus, both analgesics and paralytics each accomplish one effect, but fail to singularly account for all three. Tricaine methanesulfonate (MS-222 is structurally similar to benzocaine, a typical anesthetic for anamniote vertebrates, but contains a sulfate moiety rendering this drug more hydrophilic. MS-222 is used as anesthetic in poikilothermic animals such as fish and amphibians. However, it is often argued that MS-222 is only a hypnotic drug and its ability to block neural activity has been questioned. This prompted us to evaluate the potency and dynamics of MS-222-induced effects on neuronal firing of sensory and motor nerves alongside a defined motor behavior in semi-intact in vitro preparations of Xenopus laevis tadpoles. Electrophysiological recordings of extraocular motor discharge and both spontaneous and evoked mechanosensory nerve activity were measured before, during and after administration of MS-222, then compared to benzocaine and a known paralytic, pancuronium. Both MS-222 and benzocaine, but not pancuronium caused a dose-dependent, reversible blockade of extraocular motor and sensory nerve activity. These results indicate that MS-222 as benzocaine blocks the activity of both sensory and motor nerves compatible with the mechanistic action of effective anesthetics, indicating that both caine-derivates are effective as single-drug anesthetics for surgical interventions in anamniotes.

  14. Oxidation of molecular tritium by intact soils

    International Nuclear Information System (INIS)

    Sweet, C.W.; Murphy, C.E. Jr.

    1980-01-01

    The effects of environmental factors on the rate of oxidation of molecular tritium (T 2 ) to tritiated water (HTO) were determined for intact soils during field exposures. Maximum deposition velocities of approximately 0.03 cm/sec were measured for T 2 at low wind speeds for a variety of soils over a wide range of conditions. Deposition velocities were slightly inhibited in wet soils and at 0 0 C. In dry soils, oxidation of T 2 to HTO occurred deeper in the soil profile, but deposition velocities were unaffected

  15. Decomposition of intact chicken feathers by a thermophile in combination with an acidulocomposting garbage-treatment process.

    Science.gov (United States)

    Shigeri, Yasushi; Matsui, Tatsunobu; Watanabe, Kunihiko

    2009-11-01

    In order to develop a practical method for the decomposition of intact chicken feathers, a moderate thermophile strain, Meiothermus ruber H328, having strong keratinolytic activity, was used in a bio-type garbage-treatment machine working with an acidulocomposting process. The addition of strain H328 cells (15 g) combined with acidulocomposting in the garbage machine resulted in 70% degradation of intact chicken feathers (30 g) within 14 d. This degradation efficiency is comparable to a previous result employing the strain as a single bacterium in flask culture, and it indicates that strain H328 can promote intact feather degradation activity in a garbage machine currently on the market.

  16. Parkinson's Disease Subtypes Identified from Cluster Analysis of Motor and Non-motor Symptoms.

    Science.gov (United States)

    Mu, Jesse; Chaudhuri, Kallol R; Bielza, Concha; de Pedro-Cuesta, Jesus; Larrañaga, Pedro; Martinez-Martin, Pablo

    2017-01-01

    Parkinson's disease is now considered a complex, multi-peptide, central, and peripheral nervous system disorder with considerable clinical heterogeneity. Non-motor symptoms play a key role in the trajectory of Parkinson's disease, from prodromal premotor to end stages. To understand the clinical heterogeneity of Parkinson's disease, this study used cluster analysis to search for subtypes from a large, multi-center, international, and well-characterized cohort of Parkinson's disease patients across all motor stages, using a combination of cardinal motor features (bradykinesia, rigidity, tremor, axial signs) and, for the first time, specific validated rater-based non-motor symptom scales. Two independent international cohort studies were used: (a) the validation study of the Non-Motor Symptoms Scale ( n = 411) and (b) baseline data from the global Non-Motor International Longitudinal Study ( n = 540). k -means cluster analyses were performed on the non-motor and motor domains (domains clustering) and the 30 individual non-motor symptoms alone (symptoms clustering), and hierarchical agglomerative clustering was performed to group symptoms together. Four clusters are identified from the domains clustering supporting previous studies: mild, non-motor dominant, motor-dominant, and severe. In addition, six new smaller clusters are identified from the symptoms clustering, each characterized by clinically-relevant non-motor symptoms. The clusters identified in this study present statistical confirmation of the increasingly important role of non-motor symptoms (NMS) in Parkinson's disease heterogeneity and take steps toward subtype-specific treatment packages.

  17. Prevalence of depressive symptoms in older nursing home residents with intact cognitive function in Taiwan.

    Science.gov (United States)

    Hu, Sophia H; Chuang, Yeu-Hui; Ting, Yeh-Feng; Lin, Kuan-Yu; Hsieh, Chia-Jung

    2018-03-25

    The investigators aimed to explore the prevalence of depressive symptoms and associated factors among older residents with intact cognitive function in nursing homes in Taiwan. A cross-sectional descriptive and correlational research design was used. A convenience sample of 178 older residents without cognitive impairment was recruited from 36 nursing homes in Southern Taiwan. The questionnaires included demographic data; the Barthel Index, which assesses the ability to perform activities of daily living; and the Geriatric Depression Scale Short Form. Among older residents in nursing homes with intact cognitive function, 39.3% had depressive symptoms. Age, religion, previous living status, previous working status, being totally dependent in physical function, and being severely dependent in physical function were significant predictors of depressive symptoms among cognitively intact older residents. The findings highlight the critical mental healthcare issues among older residents with intact cognitive function in nursing homes. Practical strategies for preventing the occurrence of depressive symptoms and caring for those who have depressive symptoms should be developed, especially for younger or dependent older residents or residents who have never been employed, have no religious beliefs, or have lived alone before they moved into an institution. © 2018 Wiley Periodicals, Inc.

  18. 76 FR 647 - Energy Conservation Program: Test Procedures for Electric Motors and Small Electric Motors

    Science.gov (United States)

    2011-01-05

    ... Electric Motors and Small Electric Motors; Proposed Rule #0;#0;Federal Register / Vol. 76, No. 3... Motors and Small Electric Motors AGENCY: Office of Energy Efficiency and Renewable Energy, Department of... motors and small electric motors, clarify the scope of energy conservation standards for electric motors...

  19. Genistein Stimulates Jejunum Chloride Secretion via an Akt-Mediated Pathway in Intact Female Mice

    Directory of Open Access Journals (Sweden)

    Lana Leung

    2015-02-01

    Full Text Available Background/Aims: We have previously shown that daily subcutaneous injections with the naturally occurring phytoestrogen genistein (600 mg genistein/kg body weight/day, 600G results in a significantly increased basal intestinal chloride, Cl-, secretion (Isc, a measure of transepithelial secretion in intact C57BL/6J female mice after 1-week of treatment, compared to controls (DMSO vehicle injected. Removal of endogenous estrogen via ovariectomy (OVX had no effect on the 600G-mediated increase in basal Isc. Methods: Given the estrogen-like characteristics of genistein, we compared the effects of daily estradiol (E2 injections (10 mg E2/kg body weight/day, 10E2 on basal Isc in intact and OVX mice. In intact mice, 10E2 was without effect on basal Isc, however, in OVX mice, 10E2 significantly increased basal Isc (mimicked 600G. The goal of the current study was to characterize the intracellular signaling pathways responsible for mediating 600G- or 10E2-stimulated increases in basal Isc in intact female or OVX mice. Results: We measured total protein expression in isolated segments of jejunum using western blot from the following six groups of mice; intact or OVX with; 600G, 10E2 or control. The proteins of interest were: Akt, p-Akt, p-PDK1, p-PTEN, p-c-Raf, p-GSK-3β, rap-1 and ERK1/2. All blots were normalized to GAPDH levels (n = 6-18/group. Conclusion: These data suggest that the presence of the endogenous sex steroid, estrogen, modifies the intracellular signaling pathway required to mediate Cl- secretion when the intestine is exposed to exogenous 600G or E2. These studies may have relevance for designing pharmacological tools for women with intestinal chloride secretory dysfunctions.

  20. Chagas' disease: IgG isotypes against cytoplasmic (CRA) and flagellar (FRA) recombinant repetitive antigens of Trypanosoma cruzi in chronic Chagasic patients.

    Science.gov (United States)

    Verçosa, A F A; Lorena, V M B; Carvalho, C L; Melo, M F A D; Cavalcanti, M G A; Silva, E D; Ferreira, A G P; Pereira, V R A; Souza, W V; Gomes, Y M

    2007-01-01

    The wide range of clinical Chagas' disease manifestations, of which heart involvement is the most significant, because of its characteristics, frequency and consequences, and lack of treatment and cure, justify research in this area. Specific immunoglobulin G (IgG) antibody subclasses have been associated with human Chagas' disease. Thus, in this study, the profile of IgG subclasses against cytoplasmic (CRA) and flagellar (FRA) recombinant repetitive T. cruzi-specific antigens was correlated with cardiac (CARD, n=33), cardiodigestive (CD, n=7), and indeterminate (IND, n=20) forms of Chagas' disease by indirect enzyme-linked immunosorbent assay (ELISA). IgG subclasses were detected in almost all Chagas patients studied. Nevertheless, only specific IgG2 isotype FRA was found with a significant statistical difference in CARD patients when compared to IND patients. This result suggests the potential use of this isotype for prognostic purposes, for monitoring the progression of chronic Chagas' disease, and for predicting the risk of CARD damage. This is important information, as it could help physicians to evaluate and manage the treatment of their patients. However, a follow-up study is necessary to confirm our result. (c) 2007 Wiley-Liss, Inc.

  1. Interacting adiabatic quantum motor

    Science.gov (United States)

    Bruch, Anton; Kusminskiy, Silvia Viola; Refael, Gil; von Oppen, Felix

    2018-05-01

    We present a field-theoretic treatment of an adiabatic quantum motor. We explicitly discuss a motor called the Thouless motor which is based on a Thouless pump operating in reverse. When a sliding periodic potential is considered to be the motor degree of freedom, a bias voltage applied to the electron channel sets the motor in motion. We investigate a Thouless motor whose electron channel is modeled as a Luttinger liquid. Interactions increase the gap opened by the periodic potential. For an infinite Luttinger liquid the coupling-induced friction is enhanced by electron-electron interactions. When the Luttinger liquid is ultimately coupled to Fermi liquid reservoirs, the dissipation reduces to its value for a noninteracting electron system for a constant motor velocity. Our results can also be applied to a motor based on a nanomagnet coupled to a quantum spin Hall edge.

  2. DEVELOPMENT OF FINE MOTOR COORDINATION AND VISUAL-MOTOR INTEGRATION IN PRESCHOOL CHILDREN

    OpenAIRE

    MEMISEVIC Haris; HADZIC Selmir

    2015-01-01

    Fine motor skills are prerequisite for many everyday activities and they are a good predictor of a child's later academic outcome. The goal of the present study was to assess the effects of age on the development of fine motor coordination and visual-motor integration in preschool children. The sample for this study consisted of 276 preschool children from Canton Sara­jevo, Bosnia and Herzegovina. We assessed children's motor skills with Beery Visual Motor Integration Test and Lafayette Pegbo...

  3. 46 CFR 173.025 - Additional intact stability standards: Counterballasted vessels.

    Science.gov (United States)

    2010-10-01

    ...) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO VESSEL USE Lifting § 173.025 Additional intact stability standards: Counterballasted vessels. (a) Each vessel equipped to counterballast while lifting must be shown... loading and operation and at each combination of hook load and crane radius. (b) When doing the...

  4. In vitro permeation of palladium powders through intact and damaged human skin.

    Science.gov (United States)

    Crosera, Matteo; Mauro, Marcella; Bovenzi, Massimo; Adami, Gianpiero; Baracchini, Elena; Maina, Giovanni; Larese Filon, Francesca

    2018-05-01

    The use of palladium (Pd) has grown in the last decades, commonly used in automotive catalytic converters, jewellery and dental restorations sectors. Both general and working population can be exposed to this metal, which may act as skin sensitizer. This study investigated in vitro palladium powders permeation through excised intact and damaged human skin using the Franz diffusion cell method and the effect of rapid skin decontamination using sodium laureth-sulphate. 1 mL of a 10 min sonicated suspension made of 2.5 g of Pd powder in 50 mL synthetic sweat at pH 4.5 and room temperature was applied to the outer surface of the skin membranes for 24 h. Pd permeation, assessed by ICP-MS, was higher when damaged skin was used (p = 0.03). Final flux permeation values and lag times were 0.02 ± 0.01 μg cm -2  h -1 and 6.00 ± 3.95 h for intact, and 0.10 ± 0.02 μg cm -2  h -1 and 2.05 ± 1.49 h for damaged skin samples, respectively. Damaged skin protocol enhances Pd skin penetration inside dermal layer (p = 0.04), thus making the metal available for systemic uptake. Pd penetration (p = 0.02) and permeation (p = 0.012) through intact skin decreased significantly when a cleaning procedure was applied. This study demonstrates that after skin exposure to Pd powders a small permeation of the metal happen both through intact and damaged skin and that an early decontamination with a common cleanser can significantly decrease the final amount of metal available forsystemic uptake. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Fundamental motor skill proficiency is necessary for children's motor activity inclusion

    OpenAIRE

    Barela, José Angelo

    2013-01-01

    Motor development is influenced by many factors such as practice and appropriate instruction, provided by teachers, even in preschool and elementary school. The goal of this paper was to discuss the misconception that maturation underlies children's motor skill development and to show that physical education, even in early years of our school system, is critical to promote proficiency and enrolment of children's in later motor activities. Motor skill development, as a curricular focus, has be...

  6. IgE epitopes of intact and digested Ara h 1

    DEFF Research Database (Denmark)

    Bøgh, Katrine Lindholm; Nielsen, H.; Madsen, Charlotte Bernhard

    2012-01-01

    epitopes have been suggested to be of great importance. ObjectiveThe aim of this study was to identify IgE specific epitopes of intact and digested Ara h 1, and to compare epitope patterns between humans and rats. MethodsSera from five peanut allergic patients and five Brown Norway rats were used...... to identify intact and digested Ara h 1-specific IgE epitopes by competitive immunoscreening of a phage-displayed random hepta-mer peptide library using polyclonal IgE from the individual sera. The resulting peptide sequences were mapped on the surface of a three-dimensional structure of the Ara h 1 molecule...... to mimic epitopes using a computer-based algorithm. ResultsPatients as well as rats were shown to have individual IgE epitope patterns. All epitope mimics were conformational and found to cluster into three different areas of the Ara h 1 molecule. Five epitope motifs were identified by patient IgE, which...

  7. Discrimination between intact and decayed pulp regions in carious teeth by ADC mapping.

    Science.gov (United States)

    Cankar, Ksenija; Nemeth, Lidija; Bajd, Franci; Vidmar, Jernej; Serša, Igor

    2014-01-01

    The aim of this study was to evaluate an advanced magnetic resonance imaging (MRI) method, apparent diffusion coefficient (ADC) mapping, in the functional assessment of carious teeth. 38 extracted human teeth with scores of 0, 3 and 6 according to International Caries Detection and Assessment System (ICDAS) criteria were screened and subsequently analyzed by MRI at 2.35 T. Histology sectioning of teeth was used for the gold standard by analyzing two extreme cases (intact and severely decayed). ADC maps of the same teeth were calculated from corresponding diffusion-weighted images and used to obtain ADC distributions along dental pulp as functions of the relative pulp length measured from the occlusal pulp side. The measured distributions were analyzed for the best fit by a four-parameter three-segment linear regression model for ADC distribution along the pulp. MRI results were in good agreement with findings in histological sections of identical teeth. The best fit model parameters, relative decayed region depth, relative transition region width and ADC values of intact and decayed pulp tissue, showed statistically significant differences between the ADC values of intact and decayed pulp tissue (1.0 × 10(-9) m(2)/s vs. 0.74-0.89 × 10(-9) m(2)/s) and the relative decayed region depth progressing with ICDAS score (3 vs. 46% with ICDAS 3 vs. ICDAS 6). The results of this feasibility study confirmed relevance of ADC mapping for the discrimination and localization of intact and decayed regions in dental pulps of carious teeth. © 2014 S. Karger AG, Basel.

  8. Stepping Motor - Hydraulic Motor Servo Drives for an NC Milling ...

    African Journals Online (AJOL)

    In this paper the retrofit design of the control system of an NC milling machine with a stepping motor and stepping motor - actuated hydraulic motor servo mechanism on the machines X-axis is described. The servo designed in the course of this study was tested practically and shown to be linear - the velocity following errors ...

  9. Motor proteins and molecular motors: how to operate machines at the nanoscale

    International Nuclear Information System (INIS)

    Kolomeisky, Anatoly B

    2013-01-01

    Several classes of biological molecules that transform chemical energy into mechanical work are known as motor proteins or molecular motors. These nanometer-sized machines operate in noisy stochastic isothermal environments, strongly supporting fundamental cellular processes such as the transfer of genetic information, transport, organization and functioning. In the past two decades motor proteins have become a subject of intense research efforts, aimed at uncovering the fundamental principles and mechanisms of molecular motor dynamics. In this review, we critically discuss recent progress in experimental and theoretical studies on motor proteins. Our focus is on analyzing fundamental concepts and ideas that have been utilized to explain the non-equilibrium nature and mechanisms of molecular motors. (topical review)

  10. Motor unit recruitment by size does not provide functional advantages for motor performance.

    Science.gov (United States)

    Dideriksen, Jakob L; Farina, Dario

    2013-12-15

    It is commonly assumed that the orderly recruitment of motor units by size provides a functional advantage for the performance of movements compared with a random recruitment order. On the other hand, the excitability of a motor neuron depends on its size and this is intrinsically linked to its innervation number. A range of innervation numbers among motor neurons corresponds to a range of sizes and thus to a range of excitabilities ordered by size. Therefore, if the excitation drive is similar among motor neurons, the recruitment by size is inevitably due to the intrinsic properties of motor neurons and may not have arisen to meet functional demands. In this view, we tested the assumption that orderly recruitment is necessarily beneficial by determining if this type of recruitment produces optimal motor output. Using evolutionary algorithms and without any a priori assumptions, the parameters of neuromuscular models were optimized with respect to several criteria for motor performance. Interestingly, the optimized model parameters matched well known neuromuscular properties, but none of the optimization criteria determined a consistent recruitment order by size unless this was imposed by an association between motor neuron size and excitability. Further, when the association between size and excitability was imposed, the resultant model of recruitment did not improve the motor performance with respect to the absence of orderly recruitment. A consistent observation was that optimal solutions for a variety of criteria of motor performance always required a broad range of innervation numbers in the population of motor neurons, skewed towards the small values. These results indicate that orderly recruitment of motor units in itself does not provide substantial functional advantages for motor control. Rather, the reason for its near-universal presence in human movements is that motor functions are optimized by a broad range of innervation numbers.

  11. Blood epididymal barrier to [3H]-inulin in intact and vasectomized hamsters

    International Nuclear Information System (INIS)

    Turner, T.T.; D'Addario, D.A.; Howards, S.S.

    1981-01-01

    The net transport of [ 3 H]-inulin into the fluids of the hamster seminiferous and caput, corpus, and cauda epididymal tubules was examined in both intact animals and those vasectomized 10 months previously. Mean isotope concentrations in reproductive tract tubule fluids did not exceeded 10 per cent of blood plasma isotope concentrations during the experiment. There were no significant differences in net transport of [ 3 H]-inulin into any of the tubule fluids sampled. Ten months after vasectomy, the seminiferous tubule, and all regions of the epididymal tubule retain the capacity to exclude [ 3 H]-insulin. Thus in the hamster 10 months after vasectomy, the blood testis and blood epididymal barriers to inulin are intact

  12. Effects of ignoring baseline on modeling transitions from intact cognition to dementia.

    Science.gov (United States)

    Yu, Lei; Tyas, Suzanne L; Snowdon, David A; Kryscio, Richard J

    2009-07-01

    This paper evaluates the effect of ignoring baseline when modeling transitions from intact cognition to dementia with mild cognitive impairment (MCI) and global impairment (GI) as intervening cognitive states. Transitions among states are modeled by a discrete-time Markov chain having three transient (intact cognition, MCI, and GI) and two competing absorbing states (death and dementia). Transition probabilities depend on two covariates, age and the presence/absence of an apolipoprotein E-epsilon4 allele, through a multinomial logistic model with shared random effects. Results are illustrated with an application to the Nun Study, a cohort of 678 participants 75+ years of age at baseline and followed longitudinally with up to ten cognitive assessments per nun.

  13. Intact and Degraded Component Criticality Calculations of N Reactor Spent Nuclear Fuel

    International Nuclear Information System (INIS)

    L. Angers

    2001-01-01

    The objective of this calculation is to perform intact and degraded mode criticality evaluations of the Department of Energy's (DOE) N Reactor Spent Nuclear Fuel codisposed in a 2-Defense High-Level Waste (2-DHLW)/2-Multi-Canister Overpack (MCO) Waste Package (WP) and emplaced in a monitored geologic repository (MGR) (see Attachment I). The scope of this calculation is limited to the determination of the effective neutron multiplication factor (k eff ) for both intact and degraded mode internal configurations of the codisposal waste package. This calculation will support the analysis that will be performed to demonstrate the technical viability for disposing of U-metal (N Reactor) spent nuclear fuel in the potential MGR

  14. The kinematic portrait of a patient as an objective indicator of motor function in the process of neurorehabilitation with hand exoskeleton controlled by the brain – computer interface

    Directory of Open Access Journals (Sweden)

    А. А. Kondur

    2016-01-01

    Full Text Available The results of biomechanical analysis of the motor function of the arm of poststroke patient in the process of neuroreha bilitation with exoskeleton of the hand controlled by brain – computer interface are presented in this paper. At the beginning and end of the course it was registered the kinematic portrait of the patient– isolated random movements for each of the seven degrees of freedom as the paretic and intact arms.Angular accelerations were taken as an assessment of muscle forces, the number of reverse movements was taken as an assessment of joint spasticity, and the kinematic content of the movement as a description of pathological synergy arising after stroke. These parameters give an objective numerical asses sment of motor function as well as of rehabilitation technology effectiveness.

  15. Comparison of umbilical cord interleukin-6 in preterm infants with premature rupture of membranes and intact membranes

    International Nuclear Information System (INIS)

    Gharebaghi, Manizheh M.; Peirovifar, A.; Gharebaghi, Parvin M.

    2008-01-01

    Objective was to compare inflammatory mediators in the cord blood of premature newborn infants with premature rupture of membranes (PROM) and intact membranes. Eighty-nine premature neonates with gestational age of 27-34 weeks that delivered in Ghaem Hospital in Mashhad, Iran from June 2005 to March 2006 were enrolled in a prospective observational study and their umbilical cord plasma was collected at birth. They were allocated into 2 groups (45 patients with PROM and 44 neonates with intact membranes). Interleukin-6 (IL-6) and C-reactive protein (CRP) levels were measured in cord plasma by the enzyme linked immunoassay (ELISA) method. Mean cord plasma IL-6 levels in preterm neonates with PROM was 205.71 pg/ml and in neonates with intact membranes was 33.3 pg/ml for IL-6 (p=0.000). The mean cord blood CRP level in newborns was 10.2 ug/ml, and in those with intact membranes was 1.6 ug/ml and in those with intact membranes was 1.6 ug/ml (p=0.41). Early onset sepsis was more frequent in infants with PROM than premature infants with intact membrane (38% versus 10%, p=0.001). In neonates with PROM, the mean cord blood IL-6 level was significantly higher in septic newborns (414.28 versus 40.44 pg/ml, p=0.000). The premature newborn infants with PROM had increased IL-6 levels in cord blood, which was significantly higher in neonates that developed early onset sepsis. (author)

  16. A Recommended New Approach on Motorization Ratio Calculations of Stepper Motors

    Science.gov (United States)

    Nalbandian, Ruben; Blais, Thierry; Horth, Richard

    2014-01-01

    Stepper motors are widely used on most spacecraft mechanisms requiring repeatable and reliable performance. The unique detent torque characteristics of these type of motors makes them behave differently when subjected to low duty cycle excitations where the applied driving pulses are only energized for a fraction of the pulse duration. This phenomenon is even more pronounced in discrete permanent magnet stepper motors used in the space industry. While the inherent high detent properties of discrete permanent magnets provide desirable unpowered holding performance characteristics, it results in unique behavior especially in low duty cycles. Notably, the running torque reduces quickly to the unpowered holding torque when the duty cycle is reduced. The space industry's accepted methodology of calculating the Motorization Ratio (or Torque Margin) is more applicable to systems where the power is continuously applied to the motor coils like brushless DC motors where the cogging torques are low enough not to affect the linear performance of the motors as a function of applied current. This paper summarizes the theoretical and experimental studies performed on a number of space qualified motors under different pulse rates and duty cycles. It is the intention of this paper to introduce a new approach to calculate the Motorization Ratios for discrete permanent magnet steppers under all full and partial duty cycle regimes. The recommended approach defines two distinct relationships to calculate the Motorization Ratio for 100 percent duty cycle and partial duty cycle, when the motor detent (unpowered holding torque) is the main contributor to holding position. These two computations reflect accurately the stepper motor physical behavior as a function of the command phase (ON versus OFF times of the pulses), pointing out how the torque contributors combine. Important points highlighted under this study are the torque margin computations, in particular for well characterized

  17. Motor skills training promotes motor functional recovery and induces synaptogenesis in the motor cortex and striatum after intracerebral hemorrhage in rats.

    Science.gov (United States)

    Tamakoshi, Keigo; Ishida, Akimasa; Takamatsu, Yasuyuki; Hamakawa, Michiru; Nakashima, Hiroki; Shimada, Haruka; Ishida, Kazuto

    2014-03-01

    We investigated the effects of motor skills training on several types of motor function and synaptic plasticity following intracerebral hemorrhage (ICH) in rats. Male Wistar rats were injected with collagenase into the left striatum to induce ICH, and they were randomly assigned to the ICH or sham groups. Each group was divided into the motor skills training (acrobatic training) and control (no exercise) groups. The acrobatic group performed acrobatic training from 4 to 28 days after surgery. Motor functions were assessed by motor deficit score, the horizontal ladder test and the wide or narrow beam walking test at several time points after ICH. The number of ΔFosB-positive cells was counted using immunohistochemistry to examine neuronal activation, and the PSD95 protein levels were analyzed by Western blotting to examine synaptic plasticity in the bilateral sensorimotor cortices and striata at 14 and 29 days after ICH. Motor skills training following ICH significantly improved gross motor function in the early phase after ICH and skilled motor coordinated function in the late phase. The number of ΔFosB-positive cells in the contralateral sensorimotor cortex in the acrobatic group significantly increased compared to the control group. PSD95 protein expression in the motor cortex significantly increased in the late phase, and in the striatum, the protein level significantly increased in the early phase by motor skills training after ICH compared to no training after ICH. We demonstrated that motor skills training improved motor function after ICH in rats and enhanced the neural activity and synaptic plasticity in the striatum and sensorimotor cortex. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Piezoelectric Motors, an Overview

    Directory of Open Access Journals (Sweden)

    Karl Spanner

    2016-02-01

    Full Text Available Piezoelectric motors are used in many industrial and commercial applications. Various piezoelectric motors are available in the market. All of the piezoelectric motors use the inverse piezoelectric effect, where microscopically small oscillatory motions are converted into continuous or stepping rotary or linear motions. Methods of obtaining long moving distance have various drive and functional principles that make these motors categorized into three groups: resonance-drive (piezoelectric ultrasonic motors, inertia-drive, and piezo-walk-drive. In this review, a comprehensive summary of piezoelectric motors, with their classification from initial idea to recent progress, is presented. This review also includes some of the industrial and commercial applications of piezoelectric motors that are presently available in the market as actuators.

  19. Radiation-induced adaptive response in the intact mouse

    International Nuclear Information System (INIS)

    Yonezawa, Morio

    2009-01-01

    The author and coworkers have revealed that radiation adaptive response (AR) is seen also in the bone marrow of the intact mouse, of which details are described here. First, SPF ICR mice were pre-irradiated (PI) with 0-0.1 Gy of X-ray and after 2 months, subsequently irradiated (SI) with 7.75 Gy. Survival rates at 30 days after SI were about 14% in mice with PI 0-0.025 Gy whereas 40% or more in animals with PI 0.05-0.1 Gy: bone marrow death was found significantly suppressed in this effective PI dose range. The death 2 weeks after SI was found also inhibited at PI 0.3-0.5 Gy. Second, PI doses and interval between PI and SI for acquiring the radio-resistance (RR) were studied and third, the PI 0.3-0.5 Gy with SI 8.0 Gy at 9-17 days later revealed that regional PI of the head (central nervous system) was found unnecessary for RR and of abdomen (systems of hemopoiesis, immunity and digestion), essential. Fourth, strain difference of RR was shown by the fact that RR was observed only in C57BL mouse as well, but neither in BALB/c nor C3H strain. Next, at 12 days after SI 4.25-6.75 Gy (PI 0.5 Gy at 14 days before), mouse spleen cells were subjected to colony formation analysis by counting the endogenous hemopoietic stem cells, which revealed that those cells were increased to about 5 times by PI. Suppression of SI-induced hemorrhage was found in mice with PI by the decreased fecal hemoglobin content. Finally, AR was similarly studied in p53 +/+ and its knockout C57BL mice and was not found in the latter animal, indicating the participation of p53 in AR of the intact mouse. Elucidation of AR mechanisms in the intact animal seems to require somewhat different aspect from that in cells. The results were controvertible to the general concept that radiation risk is proportional to cumulative dose, suggesting that low dose radiation differs from high dose one in biological effect. (K.T.)

  20. Presentation of electric motor and motor control technology for electric vehicles and hybrid vehicles; Denki jidosha hybrid sha yo motor oyobi motor seigyo gijutsu no shokai

    Energy Technology Data Exchange (ETDEWEB)

    Matsudaira, N.; Masakik, R.; Tajima, F. [Hitachi, Ltd., Tokyo (Japan)

    1999-02-01

    The authors have developed a motor drive system for electric vehicles and hybrid vehicles. This system consists of a permanent magnet type synchronous motor, an inverter using insulated gate bipolar transistors (IGBTs) and a controller based on a single-chip microcomputer. To achieve a compact and light weight synchronous motor, an internal permanent magnet type rotor structure was designed. This paper presents motor control technology for electric vehicles, such as an optimization method of field weakening control and a new current control method. (author)

  1. Transfer Comparison Study Nitrogen on the Intact and Decapitated Legumes by Using the 15N Labeling Technique

    International Nuclear Information System (INIS)

    Widjayanto, Didik W.

    1998-01-01

    The experiment was done in order to evaluate the N transfer from the intact and decapitated legumes by using the 15 N labeling technique. Seven days after final labeling the above ground biomass from labeled legume species was removed and the remaining stalks capped to prevent regrowth. Twenty days after final labeling (fourteen days after capping) the all treatments were sample and analyzed. The decapitated legumes appeared to transfer more percentage N than the intact legumes. Although both decapitated and intact legumes transferred, the transfer of N did not incur a dry matter and N yield benefit

  2. Reduction of power consumption in motor-driven applications by using PM motors; PM = Permanent Magnet; Reduktion af elforbrug til motordrift ved anvendelse af PM motorer

    Energy Technology Data Exchange (ETDEWEB)

    Hvenegaard, C.M.; Hansen, Mads P.R.; Groenborg Nikolaisen, C. (Teknologisk Institut, Taastrup (Denmark)); Nielsen, Sandie B. (Teknologisk Institut, AArhus (Denmark)); Ritchie, E.; Leban, K. (Aalborg Univ., Aalborg (Denmark))

    2009-12-15

    The traditional asynchronous motor with aluminum rotor is today by far the most widespread and sold electric motor, but a new and more energy efficient type of engine - the permanent magnet motor (PM motor) - is expected in the coming years to win larger and larger market shares. Several engine manufacturers in Europe, USA and Asia are now beginning to market the PM motors, which can replace the traditional asynchronous motor. The project aims to uncover the pros and cons of replacing asynchronous motors including EFF1 engines with PM motors, including the price difference. Furthermore, it is identified how the efficiency of PM motors is affected by low load levels and at various forms of control. Finally, the energy savings potential is analysed, by replacing asynchronous motors with PM motors. The study includes laboratory tests of PM motors, made in a test stand at Danish Technological Institute. (ln)

  3. 36 CFR 292.45 - Use of motorized and non-motorized rivercraft.

    Science.gov (United States)

    2010-07-01

    ... practicable, conflicts between motorized and non-motorized rivercraft users and between both types of...-motorized rivercraft may be permitted subject to restrictions on size, type of craft, numbers, duration... Service where such activity may be permitted subject to restrictions on size, type of craft, numbers...

  4. Energy-saving motor; Energiesparmotor

    Energy Technology Data Exchange (ETDEWEB)

    Lindegger, M.

    2002-07-01

    This report for the Swiss Federal Office of Energy (SFOE) describes the development and testing of an advanced electrical motor using a permanent-magnet rotor. The aims of the project - to study the technical feasibility and market potential of the Eco-Motor - are discussed and the three phases of the project described. These include the calculation and realisation of a 250-watt prototype operating at 230 V, the measurement of the motor's characteristics as well as those of a comparable asynchronous motor on the test bed at the University of Applied Science in Lucerne, Switzerland, and a market study to establish if the Eco-Motor and its controller can compete against normal asynchronous motors. Also, the results of an analysis of the energy-savings potential is made, should such Eco-Motors be used. Detailed results of the three phases of the project are presented and the prospects of producing such motors in Switzerland for home use as well as for export are examined.

  5. 77 FR 26607 - Energy Conservation Program: Test Procedures for Electric Motors and Small Electric Motors

    Science.gov (United States)

    2012-05-04

    ... Conservation Program: Test Procedures for Electric Motors and Small Electric Motors; Final Rules #0;#0;Federal... Procedures for Electric Motors and Small Electric Motors AGENCY: Office of Energy Efficiency and Renewable... electric motors and small electric motors. That supplemental proposal, along with an earlier proposal from...

  6. Motor degradation prediction methods

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, J.R.; Kelly, J.F.; Delzingaro, M.J.

    1996-12-01

    Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor`s duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures.

  7. 46 CFR 169.684 - Overcurrent protection for motors and motor branch circuits.

    Science.gov (United States)

    2010-10-01

    ...) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Electrical Installations Operating at... motor that is responsive to motor current or to both motor current and temperature may be used. (b) The...

  8. Neuronal mechanisms of motor learning and motor memory consolidation in healthy old adults

    NARCIS (Netherlands)

    Berghuis, K. M. M.; Veldman, M. P.; Solnik, S.; Koch, G.; Zijdewind, I.; Hortobagyi, T.

    It is controversial whether or not old adults are capable of learning new motor skills and consolidate the performance gains into motor memory in the offline period. The underlying neuronal mechanisms are equally unclear. We determined the magnitude of motor learning and motor memory consolidation

  9. Microprocessor controller for stepping motors

    International Nuclear Information System (INIS)

    Strait, B.G.; Thuot, M.E.

    1977-01-01

    A new concept for digital computer control of multiple stepping motors which operate in a severe electromagnetic pulse environment is presented. The motors position mirrors in the beam-alignment system of a 100-kJ CO 2 laser. An asynchronous communications channel of a computer is used to send coded messages, containing the motor address and stepping-command information, to the stepping-motor controller in a bit serial format over a fiber-optics communications link. The addressed controller responds by transmitting to the computer its address and other motor information, thus confirming the received message. Each controller is capable of controlling three stepping motors. The controller contains the fiber-optics interface, a microprocessor, and the stepping-motor driven circuits. The microprocessor program, which resides in an EPROM, decodes the received messages, transmits responses, performs the stepping-motor sequence logic, maintains motor-position information, and monitors the motor's reference switch. For multiple stepping-motor application, the controllers are connected in a daisy chain providing control of many motors from one asynchronous communications channel of the computer

  10. Neuronal mechanisms of motor learning and motor memory consolidation in healthy old adults.

    Science.gov (United States)

    Berghuis, K M M; Veldman, M P; Solnik, S; Koch, G; Zijdewind, I; Hortobágyi, T

    2015-06-01

    It is controversial whether or not old adults are capable of learning new motor skills and consolidate the performance gains into motor memory in the offline period. The underlying neuronal mechanisms are equally unclear. We determined the magnitude of motor learning and motor memory consolidation in healthy old adults and examined if specific metrics of neuronal excitability measured by magnetic brain stimulation mediate the practice and retention effects. Eleven healthy old adults practiced a wrist extension-flexion visuomotor skill for 20 min (MP, 71.3 years), while a second group only watched the templates without movements (attentional control, AC, n = 11, 70.5 years). There was 40 % motor learning in MP but none in AC (interaction, p learn a new motor skill and consolidate the learned skill into motor memory, processes that are most likely mediated by disinhibitory mechanisms. These results are relevant for the increasing number of old adults who need to learn and relearn movements during motor rehabilitation.

  11. What happens to the motor theory of perception when the motor system is damaged?

    Science.gov (United States)

    Stasenko, Alena; Garcea, Frank E; Mahon, Bradford Z

    2013-09-01

    Motor theories of perception posit that motor information is necessary for successful recognition of actions. Perhaps the most well known of this class of proposals is the motor theory of speech perception, which argues that speech recognition is fundamentally a process of identifying the articulatory gestures (i.e. motor representations) that were used to produce the speech signal. Here we review neuropsychological evidence from patients with damage to the motor system, in the context of motor theories of perception applied to both manual actions and speech. Motor theories of perception predict that patients with motor impairments will have impairments for action recognition. Contrary to that prediction, the available neuropsychological evidence indicates that recognition can be spared despite profound impairments to production. These data falsify strong forms of the motor theory of perception, and frame new questions about the dynamical interactions that govern how information is exchanged between input and output systems.

  12. In vitro evaluation of percutaneous diffusion of uranyl nitrate through intact or excoriated skin of rat and pig

    International Nuclear Information System (INIS)

    Petitot, F.; Moreels, A.M.; Paquet, F.

    2004-01-01

    At the present time, the International Commission on Radiological Protection (ICRP) has not published any model concerning internal radioactive contamination by uptake from wounds. The aims of our work were to determine the time available to treat contamination of intact or wounded skin before a significant uptake of uranium occurred and to evaluate the consequences of incomplete decontamination on uranium uptake. The kinetics of percutaneous diffusion of uranium through intact or excoriated skin and its distribution in skin layers were evaluated using an in vitro technique. Our data demonstrated a dramatic increase of uranium percutaneous diffusion through excoriated skin compared with intact skin. Significant uptake of uranium through excoriated skin occurred in only 30 min, indicating that there is only a short interval available to treat a contaminated wound effectively. Moreover, in the case of an incompletely decontaminated superficial wound, viable epidermis behaved as a reservoir for uranium that remained bioavailable. At the present time, potential uptake of uranium and perhaps other radionuclides through intact or wounded skin is not adequately taken into account by radiological protection agencies. Our results emphasize the need for further study and modeling of uptake of radionuclides through intact or wounded skin. (author)

  13. Strength and fine dexterity recovery profiles after a primary motor cortex insult and effect of a neuronal cell graft.

    Science.gov (United States)

    Vaysse, Laurence; Conchou, Fabrice; Demain, Boris; Davoust, Carole; Plas, Benjamin; Ruggieri, Cyrielle; Benkaddour, Mehdi; Simonetta-Moreau, Marion; Loubinoux, Isabelle

    2015-08-01

    The aim of this study was to set up (a) a large primary motor cortex (M1) lesion in rodent and (b) the conditions for evaluating a long-lasting motor deficit in order to propose a valid model to test neuronal replacement therapies aimed at improving motor deficit recovery. A mitochondrial toxin, malonate, was injected to induce extensive destruction of the forelimb M1 cortex. Three key motor functions that are usually evaluated following cerebral lesion in the clinic-strength, target reaching, and fine dexterity-were assessed in rats by 2 tests, a forelimb grip strength test and a skilled reaching task (staircase) for reaching and dexterity. The potential enhancement of postlesion recovery induced by a neuronal cell transplantation was then explored and confirmed by histological analyses. Both tests showed a severe functional impairment 2 days post lesion, however, reaching remained intact. Deficits in forelimb strength were long lasting (up to 3 months) but spontaneously recovered despite the extensive lesion size. This natural grip strength recovery could be enhanced by cell therapy. Histological analyses confirmed the presence of grafted cells 3 months postgraft and showed partial tissue reconstruction with some living neuronal cells in the graft. In contrast, fine dexterity never recovered in the staircase test even after grafting. These results suggest that cell replacement was only partially effective and that the forelimb M1 area may be a node of the sensorimotor network, where compensation from secondary pathways could account for strength recovery but recovery of forelimb fine dexterity requires extensive tissue reconstruction. (c) 2015 APA, all rights reserved).

  14. Permanent magnet DC motor control by using arduino and motor drive module BTS7960

    Science.gov (United States)

    Syukriyadin, S.; Syahrizal, S.; Mansur, G.; Ramadhan, H. P.

    2018-05-01

    This study proposes a control system for permanent magnet DC (PMDC) motor. PMDC drive control system has two critical parameters: control and monitoring. Control system includes rotation speed control and direction of rotation of motor using motor drive module BTS7960. The PWM signal has a fixed frequency of waves with varying duty cycles (between 0% and 100%), so the motor rotation can be regulated gradually using a potentiometer already programmed on the Arduino Uno board. The motor rotation direction setting uses the H-bridge circuit method using a 3-way switch to set the direction of forward-reverse rotation of the motor. The monitoring system includes measurements of rotational speed, current, and voltage. Motor rotation speed can be adjusted from the armature voltage settings through the duty cycle PWM setting so that the motor speed can be increased or decreased by the desired duty cycle. From the unload PMDC motor test results it has also been shown that the torque of the motor is relatively constant when there is a change in speed from low rpm to high rpm or vice versa.

  15. Influence of fluoride varnish on shear bond strength of a universal adhesive on intact and demineralized enamel.

    Science.gov (United States)

    Ortiz-Ruiz, Antonio José; Muñoz-Gómez, Iban Jesús; Pérez-Pardo, Ana; Germán-Cecilia, Concepción; Martínez-Beneyto, Yolanda; Vicente, Ascensión

    2018-04-27

    The aim was to evaluate the effect of fluoride varnish on the shear bond strength (SBS) on polished and non-polished intact and demineralized enamel. Bovine incisors (half demineralized) were used. Bifluorid 12™ was applied. Bonding was made with Futurabond ® M + and GrandioSO, 24 h and 7 days after varnishing. In some groups, varnish was removed by polishing before bonding. SBS was measured. Fracture type was determined by stereomicroscopy and scanning electron microscope (SEM) observations of the enamel surface were made. Between-group differences were determined by one-way ANOVA and the Tukey test. Associations between study factors and fracture modes were analysed using contingency tables and Pearson's chi-squared test. For intact enamel, SBS on varnished enamel at 24 h was significantly less than in the other groups. SBS recovered 7 days after varnishing. Varnish elimination after 24 h significantly increased the SBS. However, removal at 7 days did not modify SBS. SBS on demineralized enamel groups was significantly less than in intact enamel, except for demineralized enamel varnished and removed at 7 days. Demineralized enamel was associated with cohesive enamel fractures and intact enamel with cohesive fractures of the composite and adhesive fractures. SEM of varnish surfaces showed a homogenous layer scattered with amorphous precipitate. In conclusion, on intact enamel fluoride varnish had a negative effect on SBS at 24 h, which disappeared after 7 days. On demineralized enamel, varnish did not reduce SBS at either time. Polishing the varnished enamel surface showed a similar SBS to intact enamel after 7 days.

  16. Phrenic motor neuron adenosine 2A receptors elicit phrenic motor facilitation.

    Science.gov (United States)

    Seven, Yasin B; Perim, Raphael R; Hobson, Orinda R; Simon, Alec K; Tadjalli, Arash; Mitchell, Gordon S

    2018-04-15

    Although adenosine 2A (A 2A ) receptor activation triggers specific cell signalling cascades, the ensuing physiological outcomes depend on the specific cell type expressing these receptors. Cervical spinal adenosine 2A (A 2A ) receptor activation elicits a prolonged facilitation in phrenic nerve activity, which was nearly abolished following intrapleural A 2A receptor siRNA injections. A 2A receptor siRNA injections selectively knocked down A 2A receptors in cholera toxin B-subunit-identified phrenic motor neurons, sparing cervical non-phrenic motor neurons. Collectively, our results support the hypothesis that phrenic motor neurons express the A 2A receptors relevant to A 2A receptor-induced phrenic motor facilitation. Upregulation of A 2A receptor expression in the phrenic motor neurons per se may potentially be a useful approach to increase phrenic motor neuron excitability in conditions such as spinal cord injury. Cervical spinal adenosine 2A (A 2A ) receptor activation elicits a prolonged increase in phrenic nerve activity, an effect known as phrenic motor facilitation (pMF). The specific cervical spinal cells expressing the relevant A 2A receptors for pMF are unknown. This is an important question since the physiological outcome of A 2A receptor activation is highly cell type specific. Thus, we tested the hypothesis that the relevant A 2A receptors for pMF are expressed in phrenic motor neurons per se versus non-phrenic neurons of the cervical spinal cord. A 2A receptor immunostaining significantly colocalized with NeuN-positive neurons (89 ± 2%). Intrapleural siRNA injections were used to selectively knock down A 2A receptors in cholera toxin B-subunit-labelled phrenic motor neurons. A 2A receptor knock-down was verified by a ∼45% decrease in A 2A receptor immunoreactivity within phrenic motor neurons versus non-targeting siRNAs (siNT; P phrenic motor neurons. In rats that were anaesthetized, subjected to neuromuscular blockade and ventilated, p

  17. Using Spores for Fusarium spp. Classification by MALDI-Based Intact Cell/Spore Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Wolfgang Winkler

    2012-01-01

    Full Text Available Fusarium is a widespread genus of filamentous fungi and a member of the soil microbial community. Certain subspecies are health threatening because of their mycotoxin production that affects the human and animal food chain. Thus, for early and effective pest control, species identification is of particular interest; however, differentiation on the subspecies level is challenging and time-consuming for this fungus. In the present study, we show the possibilities of intact cell mass spectrometry for spore analysis of 22 different Fusarium strains belonging to six Fusarium subspecies. We found that species differentiation is possible if mass spectrometric analyses are performed under well-defined conditions with fixed parameters. A critical point for analysis is a proper sample preparation of spores, which increases the quality of mass spectra with respect to signal intensity and m/z value variations. It was concluded that data acquistion has to be performed automatically; otherwise, user-specific variations are introduced generating data which cannot fit the existing datasets. Data that show clearly that matrix-assisted laser desorption ionization-based intact cell/intact spore mass spectrometry (IC/ISMS can be applied to differentiate closely related Fusarium spp. are presented. Results show a potential to build a database on Fusarium species for accurate species identification, for fast response in the case of infections in the cornfield. We furthermore demonstrate the high precision of our approach in classification of intact Fusarium species according to the location of their collection.

  18. Cerebellar motor learning versus cerebellar motor timing: the climbing fibre story

    Science.gov (United States)

    Llinás, Rodolfo R

    2011-01-01

    Abstract Theories concerning the role of the climbing fibre system in motor learning, as opposed to those addressing the olivocerebellar system in the organization of motor timing, are briefly contrasted. The electrophysiological basis for the motor timing hypothesis in relation to the olivocerebellar system is treated in detail. PMID:21486816

  19. The effect of self-transcendence on depression in cognitively intact nursing home patients.

    Science.gov (United States)

    Haugan, Gørill; Innstrand, Siw Tone

    2012-01-01

    Aims. This study's aim was to test the effects of self-transcendence on depression among cognitively intact nursing home patients. Background. Depression is considered the most frequent mental disorder among the elderly population. Specifically, the depression rate among nursing home patients is three to four times higher than that among community-dwelling elderly. Therefore, finding new and alternative ways to prevent and decrease depression is of great importance for nursing home patients' well-being. Self-transcendence is related to spiritual as well as nonspiritual factors, and it is described as a correlate and resource for well-being among vulnerable populations and at the end of life. Methods. A two-factor construct of the self-transcendence scale (interpersonal and intrapersonal) and the hospital anxiety and depression scale (HADS) was applied. A sample of 202 cognitively intact nursing home patients in central Norway was selected to respond to the questionnaires in 2008/2009. Results. A hypothesized SEM model demonstrated significant direct relationships and total effects of self-transcendence on depression. Conclusion and Implication for Practice. Facilitating patients' self-transcendence, both interpersonally and intrapersonally, might decrease depression among cognitively intact nursing home patients.

  20. Comparison of Linear Induction Motor Theories for the LIMRV and TLRV Motors

    Science.gov (United States)

    1978-01-01

    The Oberretl, Yamamura, and Mosebach theories of the linear induction motor are described and also applied to predict performance characteristics of the TLRV & LIMRV linear induction motors. The effect of finite motor width and length on performance ...

  1. Cryogenic Electric Motor Tested

    Science.gov (United States)

    Brown, Gerald V.

    2004-01-01

    Technology for pollution-free "electric flight" is being evaluated in a number of NASA Glenn Research Center programs. One approach is to drive propulsive fans or propellers with electric motors powered by fuel cells running on hydrogen. For large transport aircraft, conventional electric motors are far too heavy to be feasible. However, since hydrogen fuel would almost surely be carried as liquid, a propulsive electric motor could be cooled to near liquid hydrogen temperature (-423 F) by using the fuel for cooling before it goes to the fuel cells. Motor windings could be either superconducting or high purity normal copper or aluminum. The electrical resistance of pure metals can drop to 1/100th or less of their room-temperature resistance at liquid hydrogen temperature. In either case, super or normal, much higher current density is possible in motor windings. This leads to more compact motors that are projected to produce 20 hp/lb or more in large sizes, in comparison to on the order of 2 hp/lb for large conventional motors. High power density is the major goal. To support cryogenic motor development, we have designed and built in-house a small motor (7-in. outside diameter) for operation in liquid nitrogen.

  2. Construction of disturbed and intact soil blocks to develop percolating soil based treatment systems for dirty water from dairy farms.

    Science.gov (United States)

    Brookman, S K E; Chadwick, D R; Headon, D M

    2002-03-01

    Intact soil blocks with a surface area of 1.8 x 1.6 m, 1.0 m deep, were excavated in a coarse sandy loam. The sides of the soil blocks were supported with plywood before using hydraulic rams to force a steel cutting plate beneath them. Disturbed soil blocks of the same depth as the intact blocks were also established. Experiments were conducted to determine purification efficiencies for biological oxygen demand (BOD), molybdate reactive phosphorus (MRP), nitrate and ammonium-N after the application of dirty water. A preliminary experiment is described where a low application of dirty water was applied to the soil blocks, 2 mm day(-1). In addition, a chloride tracer was conducted for the duration of the experiment. Disturbed soil had a purification efficiency for BOD of 99% compared to 96% from intact soil (Pammonium-N were 100 and 99%, respectively, for the intact and disturbed soils. Nitrate-N concentration increased in leachate from both treatments reaching maximum concentrations of 15 and 8 mg l(-1) from disturbed and intact soils, respectively. Chloride traces for each soil block followed similar patterns with 47 and 51% loss from disturbed and intact soils, respectively.

  3. Assessment of Preschoolers' Gross Motor Proficiency: Revisiting Bruininks-Oseretsky Test of Motor Proficiency

    Science.gov (United States)

    Lam, Hazel Mei Yung

    2011-01-01

    Literature reveals that there are very few validated motor proficiency tests for young children. According to Gallahue and Ozmun, the Bruininks-Oseretsky Test of Motor Proficiency is a valid test. However, manipulative skills, which are classified as gross motor skills by most motor development specialists, are only tested in the Upper Limb…

  4. Motor Performance is Impaired Following Vestibular Stimulation in Ageing Mice

    Science.gov (United States)

    Tung, Victoria W. K.; Burton, Thomas J.; Quail, Stephanie L.; Mathews, Miranda A.; Camp, Aaron J.

    2016-01-01

    Balance and maintaining postural equilibrium are important during stationary and dynamic movements to prevent falls, particularly in older adults. While our sense of balance is influenced by vestibular, proprioceptive, and visual information, this study focuses primarily on the vestibular component and its age-related effects on balance. C57Bl/6J mice of ages 1, 5–6, 8–9 and 27–28 months were tested using a combination of standard (such as grip strength and rotarod) and newly-developed behavioral tests (including balance beam and walking trajectory tests with a vestibular stimulus). In the current study, we confirm a decline in fore-limb grip strength and gross motor coordination as age increases. We also show that a vestibular stimulus of low frequency (2–3 Hz) and duration can lead to age-dependent changes in balance beam performance, which was evident by increases in latency to begin walking on the beam as well as the number of times hind-feet slip (FS) from the beam. Furthermore, aged mice (27–28 months) that received continuous access to a running wheel for 4 weeks did not improve when retested. Mice of ages 1, 10, 13 and 27–28 months were also tested for changes in walking trajectory as a result of the vestibular stimulus. While no linear relationship was observed between the changes in trajectory and age, 1-month-old mice were considerably less affected than mice of ages 10, 13 and 27–28 months. Conclusion: this study confirms there are age-related declines in grip strength and gross motor coordination. We also demonstrate age-dependent changes to finer motor abilities as a result of a low frequency and duration vestibular stimulus. These changes showed that while the ability to perform the balance beam task remained intact across all ages tested, behavioral changes in task performance were observed. PMID:26869921

  5. Hereditary motor neuropathies and motor neuron diseases: which is which.

    Science.gov (United States)

    Hanemann, Clemens O; Ludolph, Albert C

    2002-12-01

    When Charcot first defined amyotrophic lateral sclerosis (ALS) he used the clinical and neuropathological pattern of vulnerability as a guideline. Similarly other motor neuron diseases such as the spinal muscular atrophies (SMA) and the motor neuropathies (MN) were grouped following clinical criteria. However, ever since the etiology of these diseases has started to be disclosed by genetics, we have learnt that the limits of the syndromes are not as well defined as our forefathers thought. A mutation leading to ALS can also be associated with the clinical picture of spinal muscular atrophy; even more unexpected is the overlap of the so-called motor neuropathies with the clinical syndrome of slowly progressive ALS or that primary lateral sclerosis (PLS) can be caused by the same gene as that responsible for some cases of ALS. In this review we summarise recent work showing that there is a considerable overlap between CMT, MN, SMA, ALS and PLS. Insights into these phenotypes should lead to study of the variants of motor neuron disease and possibly to a reclassification. This comprehensive review should help to improve understanding of the pathogenesis of motor neuron degeneration and finally may aid the research for urgently needed new treatment strategies, perhaps with validity for the entire group of motor neuron diseases.

  6. Homopolar dc motor and trapped flux brushless dc motor using high temperature superconductor materials

    Science.gov (United States)

    Crapo, Alan D.; Lloyd, Jerry D.

    1991-03-01

    Two motors have been designed and built for use with high-temperature superconductor (HTSC) materials. They are a homopolar dc motor that uses HTSC field windings and a brushless dc motor that uses bulk HTSC materials to trap flux in steel rotor poles. The HTSC field windings of the homopolar dc motor are designed to operate at 1000 A/sq cm in a 0.010-T field. In order to maximize torque in the homopolar dc motor, an iron magnetic circuit with small air gaps gives maximum flux for minimum Ampere turns in the field. A copper field winding version of the homopolar dc motor has been tested while waiting for 575 A turn HTSC coils. The trapped flux brushless dc motor has been built and is ready to test melt textured bulk HTSC rings that are currently being prepared. The stator of the trapped flux motor will impress a magnetic field in the steel rotor poles with warm HTSC bulk rings. The rings are then cooled to 77 K to trap the flux in the rotor. The motor can then operate as a brushless dc motor.

  7. Emergence of flagellar beating from the collective behavior of individual ATP-powered dyneins

    NARCIS (Netherlands)

    Namdeo, S.; Onck, P. R.

    2016-01-01

    Flagella are hair-like projections from the surface of eukaryotic cells, and they play an important role in many cellular functions, such as cell-motility. The beating of flagella is enabled by their internal architecture, the axoneme, and is powered by a dense distribution of motor proteins,

  8. Association Between Gross-Motor and Executive Function Depends on Age and Motor Task Complexity

    DEFF Research Database (Denmark)

    Spedden, Meaghan E; Malling, Anne Sofie B; Andersen, Ken K

    2017-01-01

    The objective was to examine associations between motor and executive function across the adult lifespan and to investigate the role of motor complexity in these associations. Young, middle-aged and older adults (n = 82; 19-83y) performed two gross-motor tasks with different levels of complexity...... and a Stroop-like computer task. Performance was decreased in older adults. The association between motor and cognitive performance was significant for older adults in the complex motor task (p = 0.03, rs = -0.41), whereas no significant associations were found for young or middle-aged groups, suggesting...... that the link between gross-motor and executive function emerges with age and depends on motor complexity....

  9. Feasible pickup from intact ossicular chain with floating piezoelectric microphone.

    Science.gov (United States)

    Kang, Hou-Yong; Na, Gao; Chi, Fang-Lu; Jin, Kai; Pan, Tie-Zheng; Gao, Zhen

    2012-02-22

    Many microphones have been developed to meet with the implantable requirement of totally implantable cochlear implant (TICI). However, a biocompatible one without destroying the intactness of the ossicular chain still remains under investigation. Such an implantable floating piezoelectric microphone (FPM) has been manufactured and shows an efficient electroacoustic performance in vitro test at our lab. We examined whether it pick up sensitively from the intact ossicular chain and postulated whether it be an optimal implantable one. Animal controlled experiment: five adult cats (eight ears) were sacrificed as the model to test the electroacoustic performance of the FPM. Three groups were studied: (1) the experiment group (on malleus): the FPM glued onto the handle of the malleus of the intact ossicular chains; (2) negative control group (in vivo): the FPM only hung into the tympanic cavity; (3) positive control group (Hy-M30): a HiFi commercial microphone placed close to the site of the experiment ear. The testing speaker played pure tones orderly ranged from 0.25 to 8.0 kHz. The FPM inside the ear and the HiFi microphone simultaneously picked up acoustic vibration which recorded as .wav files to analyze. The FPM transformed acoustic vibration sensitively and flatly as did the in vitro test across the frequencies above 2.0 kHz, whereas inefficiently below 1.0 kHz for its overloading mass. Although the HiFi microphone presented more efficiently than the FPM did, there was no significant difference at 3.0 kHz and 8.0 kHz. It is feasible to develop such an implantable FPM for future TICIs and TIHAs system on condition that the improvement of Micro Electromechanical System and piezoelectric ceramic material technology would be applied to reduce its weight and minimize its size.

  10. Feasible pickup from intact ossicular chain with floating piezoelectric microphone

    Directory of Open Access Journals (Sweden)

    Kang Hou-Yong

    2012-02-01

    Full Text Available Abstract Objectives Many microphones have been developed to meet with the implantable requirement of totally implantable cochlear implant (TICI. However, a biocompatible one without destroying the intactness of the ossicular chain still remains under investigation. Such an implantable floating piezoelectric microphone (FPM has been manufactured and shows an efficient electroacoustic performance in vitro test at our lab. We examined whether it pick up sensitively from the intact ossicular chain and postulated whether it be an optimal implantable one. Methods Animal controlled experiment: five adult cats (eight ears were sacrificed as the model to test the electroacoustic performance of the FPM. Three groups were studied: (1 the experiment group (on malleus: the FPM glued onto the handle of the malleus of the intact ossicular chains; (2 negative control group (in vivo: the FPM only hung into the tympanic cavity; (3 positive control group (Hy-M30: a HiFi commercial microphone placed close to the site of the experiment ear. The testing speaker played pure tones orderly ranged from 0.25 to 8.0 kHz. The FPM inside the ear and the HiFi microphone simultaneously picked up acoustic vibration which recorded as .wav files to analyze. Results The FPM transformed acoustic vibration sensitively and flatly as did the in vitro test across the frequencies above 2.0 kHz, whereas inefficiently below 1.0 kHz for its overloading mass. Although the HiFi microphone presented more efficiently than the FPM did, there was no significant difference at 3.0 kHz and 8.0 kHz. Conclusions It is feasible to develop such an implantable FPM for future TICIs and TIHAs system on condition that the improvement of Micro Electromechanical System and piezoelectric ceramic material technology would be applied to reduce its weight and minimize its size.

  11. The uptake of radioactive iodine in rat intact Graafian follicles

    International Nuclear Information System (INIS)

    Lieberman, L.M.; Lieberman, G.L.; Lieberman, M.E.

    1984-01-01

    The concentration of iodine-131 in the ovaries of mammals has important implications in the use of I-131 for the diagnosis and treatment of thyroid disease in women. The authors studied the I-131 uptake in whole ovaries and in isolated Graafian follicles of sexually mature rats. Adult female Sprague-Dawley rats, in groups of 5-6 animals, were injected IP with 10-50 μCi of I-131, at 3, 12, and 24 hrs prior to the day of proestrus and killed on the day of proestrus. The thyroid gland and ovaries were removed intact and these organs, as well as eight other tissue specimens, were weighed. The large preovulatory follicles (6-9/ovary) were then isolated under a dissecting microscope and the remaining ovary weighed. All samples were counted in a gamma well counter and the % dose/g estimated. The thyroid gland showed 23.7% dose/organ at 24 hrs. Blood decreased from 1.6% dose/g at 3 hrs to 0.5% dose/g at 24 hrs with the uterus showing 1.1% dose/g and 0.4% dose/g at the same times. Ovarian tissue was 0.5, 0.1, and 0.1% dose/g at 3,12, and 24 hrs respectively, while the intact Graafian follicles had from one-tenth to one-third the concentration of the ovary at the same times. (0.05, 0.03, and 0.03% dose/g). The authors found that the intact Graafian follicle concentrates approximately one-thirtieth to one-sixteenth of the I-131 in the blood and one-tenth to one-third of the I-131 in the ovary. This suggests that there is no active uptake of I-131 in the follicle or follicular fluid

  12. Cerebellar Shaping of Motor Cortical Firing Is Correlated with Timing of Motor Actions

    Directory of Open Access Journals (Sweden)

    Abdulraheem Nashef

    2018-05-01

    Full Text Available Summary: In higher mammals, motor timing is considered to be dictated by cerebellar control of motor cortical activity, relayed through the cerebellar-thalamo-cortical (CTC system. Nonetheless, the way cerebellar information is integrated with motor cortical commands and affects their temporal properties remains unclear. To address this issue, we activated the CTC system in primates and found that it efficiently recruits motor cortical cells; however, the cortical response was dominated by prolonged inhibition that imposed a directional activation across the motor cortex. During task performance, cortical cells that integrated CTC information fired synchronous bursts at movement onset. These cells expressed a stronger correlation with reaction time than non-CTC cells. Thus, the excitation-inhibition interplay triggered by the CTC system facilitates transient recruitment of a cortical subnetwork at movement onset. The CTC system may shape neural firing to produce the required profile to initiate movements and thus plays a pivotal role in timing motor actions. : Nashef et al. identified a motor cortical subnetwork recruited by cerebellar volley that was transiently synchronized at movement onset. Cerebellar control of cortical firing was dominated by inhibition that shaped task-related firing of neurons and may dictate motor timing. Keywords: motor control, primates, cerebellar-thalamo-cortical, synchrony, noise correlation, reaction time

  13. Behavior of high efficiency electric motors; Comportamiento de motores electricos de alta eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Bonett, Austin H. [IEEE, (United States)

    2001-09-01

    The energy efficiency is one of the main parameters in the design of the industrial motors of general purpose; nevertheless, it is avoided that it is at the cost of the reliability or to the global performance of the motor. Exist user groups of this equipment that consider that, in the search of a greater efficiency, the useful life period is diminished and the characteristics of operation of the motor are affected. During the past last years, the author has studied the aspects of quality and reliability, as well as the operative advantages of the high efficiency motors and written down the increasing interest for these aspects. Also he has detected that a great number of users has realized that, additionally to the obvious energy saving, the efficient motor offers a greater reliability and a longer useful life in most of the industrial applications. The objective of this article is to present the differences in the quality levels, reliability and operation parameters of high efficiency squirrel cage type electrical motors with those of the motors of standard manufacture. [Spanish] La eficiencia energetica es uno de los principales parametros en el diseno de los motores industriales de proposito general; sin embargo, se evita que sea a costa de la confiabilidad o del desempeno global del motor. Existen grupos de usuarios de estos equipos que consideran que, en la busqueda de una mayor eficiencia, se disminuye el periodo de vida util y se afectan las caracteristicas de operacion del motor. Durante los ultimos anos, el autor ha estudiado los aspectos de calidad y confiabilidad, asi como las ventajas operativas de los motores de alta eficiencia y anotado el incremento del interes por estos aspectos. Tambien ha detectado que un gran numero de usuarios se ha dado cuenta que, adicionalmente a los obvios ahorros de energia, el motor eficiente ofrece una mayor confiabilidad y una vida util mas larga en la mayoria de las aplicaciones industriales. El objetivo de este

  14. Calculation of ion currents across the inner membrane of functionally intact mitochondria

    Science.gov (United States)

    Kane, Daniel A; Pavlov, Evgeny V

    2013-01-01

    Mitochondrial ion transport systems play a central role in cell physiology. Rates of Ca2+ and K+ transport across the inner mitochondrial membrane have been derived from the measurement of ion accumulation over time within functional isolated mitochondria or mitochondria of cultured cells. Alternatively, the electrical currents generated by ionic flux have been directly measured in purified and swollen mitochondrial samples (mitoplasts) or reconstituted channels, and typically range from 1 pA to several 100s pA. However, the direct electrophysiological approach necessarily requires extensive processing of the mitochondria prior to measurement, which can only be performed on isolated mitoplasts. To compare rates of mitochondrial ion transport measured in electrophysiological experiments to those measured in intact mitochondria and cells, we converted published rates of mitochondrial ion uptake into units of ionic current. We estimate that for monovalent ions, uptake by intact mitochondria at the rate of 1 nmol ∙ mg−1 protein ∙ min−1 is equivalent to 0.2 fA of current per whole single mitochondrion (0.4 fA for divalent ions). In intact mitochondria, estimated rates of electrogenic cation uptake are limited to 1–100 fA of integral current per single mitochondrion. These estimates are orders of magnitude lower than the currents through mitochondrial channels directly measured via patch-clamp or artificial lipid bilayer approaches. PMID:24037064

  15. Sensory Disturbances, but Not Motor Disturbances, Induced by Sensorimotor Conflicts Are Increased in the Presence of Acute Pain

    Directory of Open Access Journals (Sweden)

    Clémentine Brun

    2017-07-01

    disturbances evoked in a given individual. Contrary to what was hypothesized, acute pain does not appear to make people more sensitive to the conflict itself, but rather impacts on the type and amount of sensory disturbances that they experienced in response to that conflict. Moreover, the results suggest that some sensorimotor integration processes remain intact in presence of acute pain, allowing us to maintain adaptive motor behavior.

  16. Comparison of capabilities of reluctance synchronous motor and induction motor

    International Nuclear Information System (INIS)

    Stumberger, Gorazd; Hadziselimovic, Miralem; Stumberger, Bojan; Miljavec, Damijan; Dolinar, Drago; Zagradisnik, Ivan

    2006-01-01

    This paper compares the capabilities of a reluctance synchronous motor (RSM) with those of an induction motor (IM). An RSM and IM were designed and made, with the same rated power and speed. They differ only in the rotor portion while their stators, housings and cooling systems are identical. The capabilities of both motors in a variable speed drive are evaluated by comparison of the results obtained by magnetically nonlinear models and by measurements

  17. Transport of beta-aminopropionitrile through intact skin or scar tissue

    International Nuclear Information System (INIS)

    Gibeault, J.D.; Cravens, R.B. Jr.; Chvapil, M.

    1989-01-01

    A lathyrogen, [ 14 C]aminopropionitrile (beta APN), was administered to 34 rats either in K-Y jelly or saline vehicles onto intact shaven skin or onto a healed splinted deep excision wound. The dynamics of beta APN transport and content in the skin or repair tissue was observed after 2, 5, 8, and 24 hr of topical administration. The repair tissue quickly absorbed the lathyrogen and reached maximum at the 2-hr sampling. The content of beta APN in the repair tissue was twice as high as that in K-Y jelly vehicle and remained high and stable for at least 24 hr only when beta APN was administered through a saline vehicle. The transport of beta APN through intact skin, irrespective of the vehicle tested, was slow and continuously increased. The study showed that almost 20% of the beta APN administered onto the wounded skin area was transported into the repair tissue within 2 hr. We suggest that, due to the absence of epidermal stratum corneum from the repair tissue, drugs, such as beta APN, penetrate quickly into the wound

  18. Enzymatic methylation of band 3 anion transporter in intact human erythrocytes

    International Nuclear Information System (INIS)

    Lou, L.L.; Clarke, S.

    1987-01-01

    Band 3, the anion transport protein of erythrocyte membranes, is a major methyl-accepting substrate of the intracellular erythrocyte protein carboxyl methyltransferase (S-adenosyl-L-methionine: protein-D-aspartate O-methyltransferase; EC 2.1.1.77). The localization of methylation sites in intact cells by analysis of proteolytic fragments indicated that sites were present in the cytoplasmic N-terminal domain as well as the membranous C-terminal portion of the polypeptide. The amino acid residues that serve as carboxyl methylation sites of the erythrocyte anion transporter were also investigated. 3 H-Methylated band 3 was purified from intact erythrocytes incubated with L-[methyl- 3 H]methionine and from trypsinized and lysed erythrocytes incubated with S-adenosyl-L-[methyl- 3 H]methionine. After proteolytic digestion with carboxypeptidase Y, D-aspartic acid beta-[ 3 H]methyl ester was isolated in low yields (9% and 1%, respectively) from each preparation. The bulk of the radioactivity was recovered as [ 3 H]methanol, and the amino acid residue(s) originally associated with these methyl groups could not be determined. No L-aspartic acid beta-[ 3 H]methyl ester or glutamyl gamma-[ 3 H]methyl ester was detected. The formation of D-aspartic acid beta-[ 3 H]methyl esters in this protein in intact cells resulted from protein carboxyl methyltransferase activity since it was inhibited by adenosine and homocysteine thiolactone, which increases the intracellular concentration of the potent product inhibitor S-adenosylhomocysteine, and cycloleucine, which prevents the formation of the substrate S-adenosyl-L-[methyl- 3 H]methionine

  19. Motor homopolar

    OpenAIRE

    Martín Muñoz, Agustín

    2007-01-01

    Mostramos la construcción de un modelo de motor homopolar, uno de los más antiguos tipos de motores eléctricos. Se caracterizan porque el campo magnético del imán mantiene siempre la misma polaridad (de ahí su nombre, del griego homos, igual), de modo que, cuando una corriente eléctrica atraviesa el campo magnético, aparece una fuerza que hace girar los elementos no fijados mecánicamente. En el sencillísimo motor homopolar colgado (Schlichting y Ucke 2004), el imán puede girar ...

  20. Electric vehicle motors and controllers

    Science.gov (United States)

    Secunde, R. R.

    1981-01-01

    Improved and advanced components being developed include electronically commutated permanent magnet motors of both drum and disk configuration, an unconventional brush commutated motor, and ac induction motors and various controllers. Test results on developmental motors, controllers, and combinations thereof indicate that efficiencies of 90% and higher for individual components, and 80% to 90% for motor/controller combinations can be obtained at rated power. The simplicity of the developmental motors and the potential for ultimately low cost electronics indicate that one or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors.

  1. IE Information No. 87-08: Degraded motor leads in Limitorque dc motor operators

    International Nuclear Information System (INIS)

    Jordan, E.L.

    1992-01-01

    On May 6, 1986 the NRC received from Portland General Electric Company a 10 CFR 21 report concerning a motor failure which occurred at its Trojan Nuclear Power Plant. The failure involved shorting of the motor leads inside a Limitorque motor operator connected to an auxiliary feedwater flow control valve. Upon inspection it was determined that the failure was the result of insulation degradation of the motor leads that had allowed two leads to short together. Recently, the NRC has also learned of a failure at the Turkey Point Nuclear Power Plant in which the steam supply valve for the auxiliary feedwater turbine failed to operate after a Limitorque motor operator experienced a similar motor lead short circuit. The Trojan and the Turkey Point Limitorque operators were found to contain motors manufactured with Nomex-Kapton insulated leads. On January 12--14, 1987, the NRC conducted an inspection at Peerless-Winsmith, Inc., manufacturer of dc motors for Limitorque Co. During this inspection it was determined that the failed Nomex-Kapton leads were different than the leads which were fitted to the motors, tested, and documented in Limitorque Qualification Report B-0009 for dc motor operators. The leads attached to the tested motors were insulated with Nomex plus an epoxy impregnated braided fiberglass sleeve. The NRC knows of no analysis or testing that has been performed to show the Nomex-Kapton leads are acceptable for use in an application requiring environmental qualification. Further, it should be noted that the failures cited above occurred under normal operating conditions, not under the harsh conditions which could occur in areas where environmental qualification is required

  2. Proceedings of the international workshop on mechanistic understanding of radionuclide migration in compacted/intact systems

    International Nuclear Information System (INIS)

    Tachi, Yukio; Yui, Mikazu

    2010-03-01

    The international workshop on mechanistic understanding of radionuclide migration in compacted / intact systems was held at ENTRY, JAEA, Tokai on 21st - 23rd January, 2009. This workshop was hosted by Japan Atomic Energy Agency (JAEA) as part of the project on the mechanistic model/database development for radionuclide sorption and diffusion behavior in compacted / intact systems. The overall goal of the project is to develop the mechanistic model / database for a consistent understanding and prediction of migration parameters and its uncertainties for performance assessment of geological disposal of radioactive waste. The objective of the workshop is to integrate the state-of-the-art of mechanistic sorption and diffusion model in compacted / intact systems, especially in bentonite / clay systems, and discuss the JAEA's mechanistic approaches and future challenges, especially the following discussions points; 1) What's the status and difficulties for mechanistic model/database development? 2) What's the status and difficulties for applicability of mechanistic model to the compacted/intact system? 3) What's the status and difficulties for obtaining evidences for mechanistic model? 4) What's the status and difficulties for standardization of experimental methodology for batch sorption and diffusion? 5) What's the uncertainties of transport parameters in radionuclides migration analysis due to a lack of understanding/experimental methodologies, and how do we derive them? This report includes workshop program, overview and materials of each presentation, summary of discussions. (author)

  3. Electrodynamic linear motor

    Energy Technology Data Exchange (ETDEWEB)

    Munehiro, H

    1980-05-29

    When driving the carriage of a printer through a rotating motor, there are problems regarding the limited accuracy of the carriage position due to rotation or contraction and ageing of the cable. In order to solve the problem, a direct drive system was proposed, in which the printer carriage is driven by a linear motor. If one wants to keep the motor circuit of such a motor compact, then the magnetic flux density in the air gap must be reduced or the motor travel must be reduced. It is the purpose of this invention to create an electrodynamic linear motor, which on the one hand is compact and light and on the other hand has a relatively high constant force over a large travel. The invention is characterised by the fact that magnetic fields of alternating polarity are generated at equal intervals in the magnetic field, and that the coil arrangement has 2 adjacent coils, whose size corresponds to half the length of each magnetic pole. A logic circuit is provided to select one of the two coils and to determine the direction of the current depending on the signals of a magnetic field sensor on the coil arrangement.

  4. Forest Loss in Protected Areas and Intact Forest Landscapes: A Global Analysis.

    Science.gov (United States)

    Heino, Matias; Kummu, Matti; Makkonen, Marika; Mulligan, Mark; Verburg, Peter H; Jalava, Mika; Räsänen, Timo A

    2015-01-01

    In spite of the high importance of forests, global forest loss has remained alarmingly high during the last decades. Forest loss at a global scale has been unveiled with increasingly finer spatial resolution, but the forest extent and loss in protected areas (PAs) and in large intact forest landscapes (IFLs) have not so far been systematically assessed. Moreover, the impact of protection on preserving the IFLs is not well understood. In this study we conducted a consistent assessment of the global forest loss in PAs and IFLs over the period 2000-2012. We used recently published global remote sensing based spatial forest cover change data, being a uniform and consistent dataset over space and time, together with global datasets on PAs' and IFLs' locations. Our analyses revealed that on a global scale 3% of the protected forest, 2.5% of the intact forest, and 1.5% of the protected intact forest were lost during the study period. These forest loss rates are relatively high compared to global total forest loss of 5% for the same time period. The variation in forest losses and in protection effect was large among geographical regions and countries. In some regions the loss in protected forests exceeded 5% (e.g. in Australia and Oceania, and North America) and the relative forest loss was higher inside protected areas than outside those areas (e.g. in Mongolia and parts of Africa, Central Asia, and Europe). At the same time, protection was found to prevent forest loss in several countries (e.g. in South America and Southeast Asia). Globally, high area-weighted forest loss rates of protected and intact forests were associated with high gross domestic product and in the case of protected forests also with high proportions of agricultural land. Our findings reinforce the need for improved understanding of the reasons for the high forest losses in PAs and IFLs and strategies to prevent further losses.

  5. Piezoelectric Motors, an Overview

    OpenAIRE

    Karl Spanner; Burhanettin Koc

    2016-01-01

    Piezoelectric motors are used in many industrial and commercial applications. Various piezoelectric motors are available in the market. All of the piezoelectric motors use the inverse piezoelectric effect, where microscopically small oscillatory motions are converted into continuous or stepping rotary or linear motions. Methods of obtaining long moving distance have various drive and functional principles that make these motors categorized into three groups: resonance-drive (piezoelectric ult...

  6. Spinal cord: motor neuron diseases.

    Science.gov (United States)

    Rezania, Kourosh; Roos, Raymond P

    2013-02-01

    Spinal cord motor neuron diseases affect lower motor neurons in the ventral horn. This article focuses on the most common spinal cord motor neuron disease, amyotrophic lateral sclerosis, which also affects upper motor neurons. Also discussed are other motor neuron diseases that only affect the lower motor neurons. Despite the identification of several genes associated with familial amyotrophic lateral sclerosis, the pathogenesis of this complex disease remains elusive. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Intact proinsulin and beta-cell function in lean and obese subjects with and without type 2 diabetes

    DEFF Research Database (Denmark)

    Røder, M E; Dinesen, B; Hartling, S G

    1999-01-01

    , total proinsulin immunoreactivity (PIM), intact insulin, and C-peptide (by radioimmunoassay) by specific enzyme-linked immunosorbent assays in the fasting state and during a 120-min glucagon (1 mg i.v.) stimulation test. Lean (BMI 23.5 +/- 0.3 kg/m2) (LD) and obese (30.1 +/- 0.4 kg/m2) (OD) type 2...... diabetic patients matched for fasting glucose (10.2 +/- 0.6 vs. 10.3 +/- 0.4 mmol/l) were compared with age- and BMI-matched lean (22.4 +/- 0.6 kg/m2) (LC) and obese (30.8 +/- 0.9 kg/m2) (OC) normal control subjects. RESULTS: Diabetic patients (LD vs. LC and OD vs. OC) had elevated fasting levels of intact......, most pronounced in the lean group. The ratio of intact proinsulin to PIM was higher in diabetic patients after stimulation in both LD versus LC: 32 +/- 3 vs. 23 +/- 2%, and OD versus OC: 28 +/- 4 vs. 16 +/- 2%, both P obese normal subjects, intact proinsulin/PIM was lower both in the fasting...

  8. Higher Efficiency HVAC Motors

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, Charles Joseph [QM Power, Inc., Kansas City, MO (United States)

    2018-02-13

    The objective of this project was to design and build a cost competitive, more efficient heating, ventilation, and air conditioning (HVAC) motor than what is currently available on the market. Though different potential motor architectures among QMP’s primary technology platforms were investigated and evaluated, including through the building of numerous prototypes, the project ultimately focused on scaling up QM Power, Inc.’s (QMP) Q-Sync permanent magnet synchronous motors from available sub-fractional horsepower (HP) sizes for commercial refrigeration fan applications to larger fractional horsepower sizes appropriate for HVAC applications, and to add multi-speed functionality. The more specific goal became the research, design, development, and testing of a prototype 1/2 HP Q-Sync motor that has at least two operating speeds and 87% peak efficiency compared to incumbent electronically commutated motors (EC or ECM, also known as brushless direct current (DC) motors), the heretofore highest efficiency HVACR fan motor solution, at approximately 82% peak efficiency. The resulting motor prototype built achieved these goals, hitting 90% efficiency and .95 power factor at full load and speed, and 80% efficiency and .7 power factor at half speed. Q-Sync, developed in part through a DOE SBIR grant (Award # DE-SC0006311), is a novel, patented motor technology that improves on electronically commutated permanent magnet motors through an advanced electronic circuit technology. It allows a motor to “sync” with the alternating current (AC) power flow. It does so by eliminating the constant, wasteful power conversions from AC to DC and back to AC through the synthetic creation of a new AC wave on the primary circuit board (PCB) by a process called pulse width modulation (PWM; aka electronic commutation) that is incessantly required to sustain motor operation in an EC permanent magnet motor. The Q-Sync circuit improves the power factor of the motor by removing all

  9. Protein methylation reactions in intact pea chloroplasts

    International Nuclear Information System (INIS)

    Niemi, K.J.

    1989-01-01

    Post-translational protein methylation was investigated in Pisum sativum chloroplasts. Intact pea chloroplasts were incubated with ( 3 H-methyl)-S-adenosylmethionine under various conditions. The chloroplasts were then separated into stromal and thylakoid fractions and analyzed for radioactivity transferred to protein. Light enhanced the magnitude of labeling in both fractions. One thylakoid polypeptide with an apparent molecular mass of 43 kDa was labeled only in the light. Several other thylakoid and stromal proteins were labeled in both light and dark-labeling conditions. Both base-labile methylation, carboxy-methylesters and base-stable groups, N-methylations were found. Further characterization of the methyl-transfer reactions will be presented

  10. Motor degradation prediction methods

    International Nuclear Information System (INIS)

    Arnold, J.R.; Kelly, J.F.; Delzingaro, M.J.

    1996-01-01

    Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor's duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures

  11. Characterization of the anion sensitive ATPase in intact vacuoles of Kalanchoe diagremontiana

    Energy Technology Data Exchange (ETDEWEB)

    Kobza, J.; Uribe, E.G.

    1986-04-01

    A method for the isolation of intact vacuoles from K. daigremontiana was developed which produced high yields of relatively pure vacuoles as determined by marker enzyme contamination. Upon isolation, the vacuoles were stabilized by the inclusion of 5% (w/v) ficoll. Enzyme activity was insensitive to vanadate and azide but was strongly inhibited by DCCD. Enzyme activity was strictly dependent on the inclusion of Mg/sup 2 +/ and was stimulated by anions as depicted by the series, NO/sub 3//sup -/ < Br/sup -/ < SO/sub 4//sup -/ < HCO/sub 3//sup -/ < Cl/sup -/. It was found that in intact vacuoles the ATPase activity was stimulated by phosphate to a level equivalent to that found with the chloride. The enzyme exhibited Michaelis-Menten kinetics with a Km for Mg-ATP complex of 0.51 mM.

  12. Motor Importance of motor assessment in school children: analysis of the reliability of the motor development scale

    Directory of Open Access Journals (Sweden)

    Kassandra Nunes Amaro

    2010-09-01

    Full Text Available The objective of this study was to investigate the motor performance of school chil-dren aged 6 to 10 years without learning difficulties (n=101, and to analyze the reliability of the Motor Development Scale (MDS (Rosa Neto, 2002. Descriptive statistics with calculation of the mean, standard deviation, and range was used for data analysis. The internal consistency of the MDS was assessed using Cronbach’s alpha coefficient, and the correlation between variables was determined by Pearson’s linear correlation, with p<0.05. The results showed (1 that motor development was within normal limits in 96% of the children, and (2 a high correlation betwe-en chronological age and general motor age, indicating good internal consistency. These data demonstrate the logic and structured design of the MDS, confirming its reliability.

  13. Microseismic Analysis of Fracture of an Intact Rock Asperity Traversing a Sawcut Fault

    Science.gov (United States)

    Mclaskey, G.; Lockner, D. A.

    2017-12-01

    Microseismic events carry information related to stress state, fault geometry, and other subsurface properties, but their relationship to large and potentially damaging earthquakes is not well defined. We conducted laboratory rock mechanics experiments that highlight the interaction between a sawcut fault and an asperity composed of an intact rock "pin". The sample is a 76 mm diameter cylinder of Westerly granite with a 21 mm diameter cylinder (the pin) of intact Westerly granite that crosses the sawcut fault. Upon loading to 80 MPa in a triaxial machine, we first observed a slip event that ruptured the sawcut fault, slipped about 35 mm, but was halted by the rock pin. With continued loading, the rock pin failed in a swarm of thousands of M -7 seismic events similar to the localized microcracking that occurs during the final fracture nucleation phase in an intact rock sample. Once the pin was fractured to a critical point, it permitted complete rupture events on the sawcut fault (stick-slip instabilities). No seismicity was detected on the sawcut fault plane until the pin was sheared. Subsequent slip events were preceded by 10s of foreshocks, all located on the fault plane. We also identified an aseismic zone on the fault plane surrounding the fractured rock pin. A post-mortem analysis of the sample showed a thick gouge layer where the pin intersected the fault, suggesting that this gouge propped open the fault and prevented microseismic events in its vicinity. This experiment is an excellent case study in microseismicity since the events separate neatly into three categories: slip on the sawcut fault, fracture of the intact rock pin, and off-fault seismicity associated with pin-related rock joints. The distinct locations, timing, and focal mechanisms of the different categories of microseismic events allow us to study how their occurrence is related to the mechanics of the deforming rock.

  14. Mechanical design of electric motors

    CERN Document Server

    Tong, Wei

    2014-01-01

    Rapid increases in energy consumption and emphasis on environmental protection have posed challenges for the motor industry, as has the design and manufacture of highly efficient, reliable, cost-effective, energy-saving, quiet, precisely controlled, and long-lasting electric motors.Suitable for motor designers, engineers, and manufacturers, as well as maintenance personnel, undergraduate and graduate students, and academic researchers, Mechanical Design of Electric Motors provides in-depth knowledge of state-of-the-art design methods and developments of electric motors. From motor classificati

  15. Markov process of muscle motors

    International Nuclear Information System (INIS)

    Kondratiev, Yu; Pechersky, E; Pirogov, S

    2008-01-01

    We study a Markov random process describing muscle molecular motor behaviour. Every motor is either bound up with a thin filament or unbound. In the bound state the motor creates a force proportional to its displacement from the neutral position. In both states the motor spends an exponential time depending on the state. The thin filament moves at a velocity proportional to the average of all displacements of all motors. We assume that the time which a motor stays in the bound state does not depend on its displacement. Then one can find an exact solution of a nonlinear equation appearing in the limit of an infinite number of motors

  16. Motor demand-dependent activation of ipsilateral motor cortex.

    Science.gov (United States)

    Buetefisch, Cathrin M; Revill, Kate Pirog; Shuster, Linda; Hines, Benjamin; Parsons, Michael

    2014-08-15

    The role of ipsilateral primary motor cortex (M1) in hand motor control during complex task performance remains controversial. Bilateral M1 activation is inconsistently observed in functional (f)MRI studies of unilateral hand performance. Two factors limit the interpretation of these data. As the motor tasks differ qualitatively in these studies, it is conceivable that M1 contributions differ with the demand on skillfulness. Second, most studies lack the verification of a strictly unilateral execution of the motor task during the acquisition of imaging data. Here, we use fMRI to determine whether ipsilateral M1 activity depends on the demand for precision in a pointing task where precision varied quantitatively while movement trajectories remained equal. Thirteen healthy participants used an MRI-compatible joystick to point to targets of four different sizes in a block design. A clustered acquisition technique allowed simultaneous fMRI/EMG data collection and confirmed that movements were strictly unilateral. Accuracy of performance increased with target size. Overall, the pointing task revealed activation in contralateral and ipsilateral M1, extending into contralateral somatosensory and parietal areas. Target size-dependent activation differences were found in ipsilateral M1 extending into the temporal/parietal junction, where activation increased with increasing demand on accuracy. The results suggest that ipsilateral M1 is active during the execution of a unilateral motor task and that its activity is modulated by the demand on precision. Copyright © 2014 the American Physiological Society.

  17. Motor network structure and function are associated with motor performance in Huntington's disease.

    Science.gov (United States)

    Müller, Hans-Peter; Gorges, Martin; Grön, Georg; Kassubek, Jan; Landwehrmeyer, G Bernhard; Süßmuth, Sigurd D; Wolf, Robert Christian; Orth, Michael

    2016-03-01

    In Huntington's disease, the relationship of brain structure, brain function and clinical measures remains incompletely understood. We asked how sensory-motor network brain structure and neural activity relate to each other and to motor performance. Thirty-four early stage HD and 32 age- and sex-matched healthy control participants underwent structural magnetic resonance imaging (MRI), diffusion tensor, and intrinsic functional connectivity MRI. Diffusivity patterns were assessed in the cortico-spinal tract and the thalamus-somatosensory cortex tract. For the motor network connectivity analyses the dominant M1 motor cortex region and for the basal ganglia-thalamic network the thalamus were used as seeds. Region to region structural and functional connectivity was examined between thalamus and somatosensory cortex. Fractional anisotropy (FA) was higher in HD than controls in the basal ganglia, and lower in the external and internal capsule, in the thalamus, and in subcortical white matter. Between-group axial and radial diffusivity differences were more prominent than differences in FA, and correlated with motor performance. Within the motor network, the insula was less connected in HD than in controls, with the degree of connection correlating with motor scores. The basal ganglia-thalamic network's connectivity differed in the insula and basal ganglia. Tract specific white matter diffusivity and functional connectivity were not correlated. In HD sensory-motor white matter organization and functional connectivity in a motor network were independently associated with motor performance. The lack of tract-specific association of structure and function suggests that functional adaptation to structural loss differs between participants.

  18. Task-dependent activation of distinct fast and slow(er) motor pathways during motor imagery.

    Science.gov (United States)

    Keller, Martin; Taube, Wolfgang; Lauber, Benedikt

    2018-02-22

    Motor imagery and actual movements share overlapping activation of brain areas but little is known about task-specific activation of distinct motor pathways during mental simulation of movements. For real contractions, it was demonstrated that the slow(er) motor pathways are activated differently in ballistic compared to tonic contractions but it is unknown if this also holds true for imagined contractions. The aim of the present study was to assess the activity of fast and slow(er) motor pathways during mentally simulated movements of ballistic and tonic contractions. H-reflexes were conditioned with transcranial magnetic stimulation at different interstimulus intervals to assess the excitability of fast and slow(er) motor pathways during a) the execution of tonic and ballistic contractions, b) motor imagery of these contraction types, and c) at rest. In contrast to the fast motor pathways, the slow(er) pathways displayed a task-specific activation: for imagined ballistic as well as real ballistic contractions, the activation was reduced compared to rest whereas enhanced activation was found for imagined tonic and real tonic contractions. This study provides evidence that the excitability of fast and slow(er) motor pathways during motor imagery resembles the activation pattern observed during real contractions. The findings indicate that motor imagery results in task- and pathway-specific subliminal activation of distinct subsets of neurons in the primary motor cortex. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  19. Survival motor neuron protein in motor neurons determines synaptic integrity in spinal muscular atrophy.

    Science.gov (United States)

    Martinez, Tara L; Kong, Lingling; Wang, Xueyong; Osborne, Melissa A; Crowder, Melissa E; Van Meerbeke, James P; Xu, Xixi; Davis, Crystal; Wooley, Joe; Goldhamer, David J; Lutz, Cathleen M; Rich, Mark M; Sumner, Charlotte J

    2012-06-20

    The inherited motor neuron disease spinal muscular atrophy (SMA) is caused by deficient expression of survival motor neuron (SMN) protein and results in severe muscle weakness. In SMA mice, synaptic dysfunction of both neuromuscular junctions (NMJs) and central sensorimotor synapses precedes motor neuron cell death. To address whether this synaptic dysfunction is due to SMN deficiency in motor neurons, muscle, or both, we generated three lines of conditional SMA mice with tissue-specific increases in SMN expression. All three lines of mice showed increased survival, weights, and improved motor behavior. While increased SMN expression in motor neurons prevented synaptic dysfunction at the NMJ and restored motor neuron somal synapses, increased SMN expression in muscle did not affect synaptic function although it did improve myofiber size. Together these data indicate that both peripheral and central synaptic integrity are dependent on motor neurons in SMA, but SMN may have variable roles in the maintenance of these different synapses. At the NMJ, it functions at the presynaptic terminal in a cell-autonomous fashion, but may be necessary for retrograde trophic signaling to presynaptic inputs onto motor neurons. Importantly, SMN also appears to function in muscle growth and/or maintenance independent of motor neurons. Our data suggest that SMN plays distinct roles in muscle, NMJs, and motor neuron somal synapses and that restored function of SMN at all three sites will be necessary for full recovery of muscle power.

  20. Length of time domestic dogs (Canis familiaris) spend smelling urine of gonadectomised and intact conspecifics.

    Science.gov (United States)

    Riach, Anna C; Asquith, Rachel; Fallon, Melissa L D

    2017-09-01

    Domestic dogs (Canis familiaris) use urine to communicate among themselves, however, it is unknown whether the gonadectomy (neutering or spaying) of a dog affects this communication in anyway. Urine samples from 10 intact and 10 gonadectomised, unfamiliar dogs were presented to 12 tester dogs to sniff under controlled conditions in a pilot study. The amount of time the tester dogs spent sniffing each sample was recorded. Overall, tester dogs were recorded smelling the urine of gonadectomised individuals for a longer time. In addition to the type of urine sample, the result is likely to have been influenced by the sex and status (gonadectomised or intact) of the tester dogs. The observed increase in the length of time spent sniffing urine from gonadectomised individuals could be explained by the tester dogs experiencing more difficulty in gaining information from the urine or facing more confusion while analysing the urine compared to the intact urine they have evolved to smell. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Motor Skill Competence and Perceived Motor Competence: Which Best Predicts Physical Activity among Girls?

    OpenAIRE

    Khodaverdi, Zeinab; Bahram, Abbas; Khalaji, Hassan; Kazemnejad, Anoshirvan

    2013-01-01

    Abstract Background The main purpose of this study was to determine which correlate, perceived motor competence or motor skill competence, best predicts girls? physical activity behavior. Methods A sample of 352 girls (mean age=8.7, SD=0.3 yr) participated in this study. To assess motor skill competence and perceived motor competence, each child completed the Test of Gross Motor Development-2 and Physical Ability sub-scale of Marsh?s Self-Description Questionnaire. Children?s physical activit...

  2. Isolation and Properties of Intact Chromoplasts from Tomato Fruits

    OpenAIRE

    Norio, Iwatsuki; Ryuichi, Moriyama; Tadashi, Asahi; Laboratory of Biochemistry, Faculty of Agriculture, Nagoya University; Laboratory of Biochemistry, Faculty of Agriculture, Nagoya University; Laboratory of Biochemistry, Faculty of Agriculture, Nagoya University

    1984-01-01

    Intact chromoplasts were isolated from tomato fruits at different ripening stages by Percoll density gradient centrifugation. The isolated chromoplast fractions were contaminated very little by other organelles, although the fraction from fully ripened fruits contained some mitochondria and microbodies. As the transformation of chloroplasts to chromoplasts proceeded, the density of the plastids decreased from 1.096 to 1.075g・cm^ and the decrease was related to a decrease in chlorophyll and an...

  3. The influence of motor imagery on the learning of a fine hand motor skill

    NARCIS (Netherlands)

    Sobierajewicz, Jagna; Przekoracka-Krawczyk, Anna; Jaśkowski, Wojciech; Verwey, Willem B.; van der Lubbe, Rob

    2017-01-01

    Motor imagery has been argued to affect the acquisition of motor skills. The present study examined the specificity of motor imagery on the learning of a fine hand motor skill by employing a modified discrete sequence production task: the Go/NoGo DSP task. After an informative cue, a response

  4. Conductive hearing loss with an intact tympanic membrane due to non-inflammatory causes.

    Science.gov (United States)

    Choi, Jin Hyuk; Lee, Min Young; Park, Ji Hye; Lee, Kyu-Yup; Lee, Sang Heun; Jang, Jeong Hun

    2016-04-01

    We analyzed audiologic and surgical findings in patients with conductive hearing loss (CHL) with an intact tympanic membrane (TM) that was of a non-inflammatory origin. We reviewed data from patients who underwent exploratory tympanotomy for CHL with intact TM from January 1995 to November 2012. Patients with diseases of non-inflammatory origin were enrolled (69 patients; 79 ears). Patients were categorized into two groups: non-trauma (50 ears) and trauma (29 ears). Demographic data, intraoperative findings, and audiologic results were obtained and analyzed. Overall, the second decade was the most common age of diagnosis in both the non-trauma and trauma groups. Operative findings showed that ossicular dislocation was more prevalent than ossicular fixation; all trauma group subjects had ossicular dislocation. Short columellization or partial ossicular replacement was the most frequently adopted surgical procedures in both groups. Overall, audiologically, air-conduction thresholds (ACs) and air-bone gaps were significantly improved over the short- and long-term period in both groups. However, the non-trauma group had significantly higher preoperative ACs than the trauma group, especially at low frequencies. This study provides clinicians with useful information regarding the clinical characteristics of CHL with intact TM of non-inflammatory origin. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. Deafness and motor abilities level

    Directory of Open Access Journals (Sweden)

    A Zwierzchowska

    2008-09-01

    Full Text Available The audition injury hinders some motor motions and the organised coordination at the higher level and may be a cause of disturbances and disorder in some motor abilities adoption. It was assumed that deafness including its aetiology and injury mechanism may significantly influence the motor development of human being. The study aimed in checking if the deafness, as a result of various unfavourable factors, determines the motor development of children and youngsters. Consequently the dependency between qualitative features i.e.: signed motor level and aetiology, audition injury mechanism and the deafness degree was examined. The mechanism and aetiology of hearing correlated with the motor abilities displayed statistically significant dependencies in few motor trials only. Revealed correlations regarded mostly the coordination trials excluding the flexibility one. Statistically significant dependencies between the audition diminution and the motor abilities level were not found.

  6. Insight into the Supramolecular Architecture of Intact Diatom Biosilica from DNP-Supported Solid-State NMR Spectroscopy.

    Science.gov (United States)

    Jantschke, Anne; Koers, Eline; Mance, Deni; Weingarth, Markus; Brunner, Eike; Baldus, Marc

    2015-12-07

    Diatom biosilica is an inorganic/organic hybrid with interesting properties. The molecular architecture of the organic material at the atomic and nanometer scale has so far remained unknown, in particular for intact biosilica. A DNP-supported ssNMR approach assisted by microscopy, MS, and MD simulations was applied to study the structural organization of intact biosilica. For the first time, the secondary structure elements of tightly biosilica-associated native proteins in diatom biosilica were characterized in situ. Our data suggest that these proteins are rich in a limited set of amino acids and adopt a mixture of random-coil and β-strand conformations. Furthermore, biosilica-associated long-chain polyamines and carbohydrates were characterized, thereby leading to a model for the supramolecular organization of intact biosilica. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Prototypic and Arkypallidal Neurons in the Dopamine-Intact External Globus Pallidus

    Science.gov (United States)

    Abdi, Azzedine; Mallet, Nicolas; Mohamed, Foad Y.; Sharott, Andrew; Dodson, Paul D.; Nakamura, Kouichi C.; Suri, Sana; Avery, Sophie V.; Larvin, Joseph T.; Garas, Farid N.; Garas, Shady N.; Vinciati, Federica; Morin, Stéphanie; Bezard, Erwan

    2015-01-01

    Studies in dopamine-depleted rats indicate that the external globus pallidus (GPe) contains two main types of GABAergic projection cell; so-called “prototypic” and “arkypallidal” neurons. Here, we used correlative anatomical and electrophysiological approaches in rats to determine whether and how this dichotomous organization applies to the dopamine-intact GPe. Prototypic neurons coexpressed the transcription factors Nkx2-1 and Lhx6, comprised approximately two-thirds of all GPe neurons, and were the major GPe cell type innervating the subthalamic nucleus (STN). In contrast, arkypallidal neurons expressed the transcription factor FoxP2, constituted just over one-fourth of GPe neurons, and innervated the striatum but not STN. In anesthetized dopamine-intact rats, molecularly identified prototypic neurons fired at relatively high rates and with high regularity, regardless of brain state (slow-wave activity or spontaneous activation). On average, arkypallidal neurons fired at lower rates and regularities than prototypic neurons, and the two cell types could be further distinguished by the temporal coupling of their firing to ongoing cortical oscillations. Complementing the activity differences observed in vivo, the autonomous firing of identified arkypallidal neurons in vitro was slower and more variable than that of prototypic neurons, which tallied with arkypallidal neurons displaying lower amplitudes of a “persistent” sodium current important for such pacemaking. Arkypallidal neurons also exhibited weaker driven and rebound firing compared with prototypic neurons. In conclusion, our data support the concept that a dichotomous functional organization, as actioned by arkypallidal and prototypic neurons with specialized molecular, structural, and physiological properties, is fundamental to the operations of the dopamine-intact GPe. PMID:25926446

  8. Motor fuel prices in Turkey

    International Nuclear Information System (INIS)

    Erdogdu, Erkan

    2014-01-01

    The world's most expensive motor fuel (gasoline, diesel and LPG) is sold most likely in the Republic of Turkey. This paper investigates the key issues related to the motor fuel prices in Turkey. First of all, the paper analyses the main reason behind high prices, namely motor fuel taxes in Turkey. Then, it estimates the elasticity of motor fuel demand in Turkey using an econometric analysis. The findings indicate that motor fuel demand in Turkey is quite inelastic and, therefore, not responsive to price increases caused by an increase in either pre-tax prices or taxes. Therefore, fuel market in Turkey is open to opportunistic behavior by firms (through excessive profits) and the government (through excessive taxes). Besides, the paper focuses on the impact of high motor fuel prices on road transport associated activities, including the pattern of passenger transportation, motorization rate, fuel use, total kilometers traveled and CO 2 emissions from road transportation. The impact of motor fuel prices on income distribution in Turkey and Turkish public opinion about high motor fuel prices are also among the subjects investigated in the course of the study. - Highlights: • The key issues (e.g. taxes) related to motor fuel prices in Turkey are explored. • Their impact on transport activities and income distribution is also investigated. • An econometric analysis is performed to estimate motor fuel demand in Turkey. • Motor fuel demand in Turkey is found to be quite inelastic. • Turkish fuel market is open to opportunistic behavior by firms and the government

  9. Ingested soluble CD14 from milk is transferred intact into the blood of newborn rats.

    Science.gov (United States)

    Ward, Tonya L; Spencer, William J; Davis, Laura D R; Harrold, Joann; Mack, David R; Altosaar, Illimar

    2014-02-01

    Milk acts as an edible immune system that is transferred from mother to newborn. Soluble Cluster of Differentiation 14 (sCD14) is a protein found in significant quantities in human milk (~8-29 µg/ml). At a 10-fold lower concentration in the blood (~3 µg/ml), the most notable role of sCD14 is to sequester lipopolysaccharides of Gram-negative bacteria from immune cells. To explore the pharmacodynamics of this milk protein and its biological fate, the biodistribution of radiolabeled sCD14 ((14)C, (125)I) was monitored in 10-d-old rat pups. Up to 3.4 ± 2.2% of the radiolabeled sCD14 administered was observed, intact, in the pup blood for up to 8 h post-ingestion. Additionally, 30.3 ± 13.0% of the radiolabeled sCD14 administered was observed degraded in the stomach at 8 h post-ingestion. A reservoir of intact, administered sCD14 (3.2 ± 0.3%), however, remained in the stomach at 8 h post-ingestion. Intact sCD14 was observed in the small intestine at 5.5 ± 1.6% of the dose fed at 8 h post-ingestion. The presence of intact sCD14 in the blood and the gastrointestinal tract of newborns post-ingestion has implications in the development of allergies, obesity, and other inflammation-related pathogeneses later in life.

  10. Increasing Mud Pump Motor Reliability against Malfunctions of DC Motor Excitation System

    Science.gov (United States)

    Nikulin, O. V.; Shabanov, V. A.

    2017-10-01

    The most widely used drilling machinery, such as mud pumps, draw-works, and rotors, use direct-current (DC) motors with independent excitation as the electric drive. Drilling machinery drives operate in harsh ambient conditions, including those with the presence of moisture, dust and vibration, which increases the malfunction rate of both drilling equipment and their electric drives. One of the frequently encountered malfunctions are DC motor excitation coil faults, which disrupt the normal functioning of electric drives, often leading to shutdown of the drilling process. In a four-pole DC motor, the malfunction of one coil leads to lack of excitation current in just one coil pair, while the other pair remains functional. In this case, DC motors and drilling equipment can remain operational, which would allow for continuing the drilling process. This paper considers the possibility of operation of a DC motor on a drilling rig in those cases when one pair of excitation coils is non-functional, and describes the device for switching between the excitation coils and the auxiliary winding in a DC motor with independent excitation.

  11. A method to detect transfected chloramphenicol acetyltransferase gene expression in intact animals

    International Nuclear Information System (INIS)

    Narayanan, R.; Jastreboff, M.M.; Chiu, Chang Fang; Ito, Etsuro; Bertino, J.R.

    1988-01-01

    A rapid procedure is described for assaying chloramphenicol acetyltransferase enzyme activity in intact animals following transfection of the RSV CAT plasmid into mouse bone marrow cells by electroporation. The reconstituted mice were injected with [ 14 C]chloramphenicol and ethyl acetate extracts of 24-h urine samples were analyzed by TLC autoradiography for the excretion of 14 C-labeled metabolites. CAT expression in vivo can be detected by the presence of acetylated 14 C-labeled metabolites in the urine within 1 week after bone marrow transplantation and, under the conditions described, these metabolites can be detected for at least 3 months. CAT expression in intact mice as monitored by the urine assay correlates with the CAT expression in the hematopoietic tissues assayed in vitro. This method offers a quick mode of screening for introduced CAT gene expression in vivo without sacrificing the mice

  12. Changes of motor-cortical oscillations associated with motor learning.

    Science.gov (United States)

    Pollok, B; Latz, D; Krause, V; Butz, M; Schnitzler, A

    2014-09-05

    Motor learning results from practice but also between practice sessions. After skill acquisition early consolidation results in less interference with other motor tasks and even improved performance of the newly learned skill. A specific significance of the primary motor cortex (M1) for early consolidation has been suggested. Since synchronized oscillatory activity is assumed to facilitate neuronal plasticity, we here investigate alterations of motor-cortical oscillations by means of event-related desynchronization (ERD) at alpha (8-12 Hz) and beta (13-30 Hz) frequencies in healthy humans. Neuromagnetic activity was recorded using a 306-channel whole-head magnetoencephalography (MEG) system. ERD was investigated in 15 subjects during training on a serial reaction time task and 10 min after initial training. The data were compared with performance during a randomly varying sequence serving as control condition. The data reveal a stepwise decline of alpha-band ERD associated with faster reaction times replicating previous findings. The amount of beta-band suppression was significantly correlated with reduction of reaction times. While changes of alpha power have been related to lower cognitive control after initial skill acquisition, the present data suggest that the amount of beta suppression represents a neurophysiological marker of early cortical reorganization associated with motor learning. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Beta Adrenergic Regulation of Intrapulmonary Arteriovenous Anastomoses in Intact Rat and Isolated Rat Lungs

    Directory of Open Access Journals (Sweden)

    Melissa L. Bates

    2017-04-01

    Full Text Available Intrapulmonary arteriovenous anastomoses (IPAVA allow large diameter particles of venous origin to bypass the pulmonary capillary bed and embolize the systemic arterial circulation. IPAVA have been routinely observed in healthy humans with exercise, hypoxia, and catecholamine infusion, but the mechanism by which they are recruited is not well-defined. We hypothesized that beta-adrenergic receptor stimulation recruits IPAVA and that receptor blockade would limit hypoxia-induced IPAVA recruitment. To test our hypothesis, we evaluated the transpulmonary passage of microspheres in intact rats and isolated rats lung infused with the beta-adrenergic receptor agonist isoproterenol. We also evaluated IPAVA recruitment in intact rats with hypoxia and the beta-adrenergic receptor blocker propranolol. We found that IPAVA are recruited in the intact rat by isoproterenol and their recruitment by hypoxia can be minimized by propranolol, suggesting a role for the adrenergic system in the recruitment of IPAVA by hypoxia. IPAVA recruitment is completely abolished by ventilation with 100% oxygen. Isoproterenol also recruits IPAVA in isolated rat lungs. The fact that isoproterenol can recruit IPAVA in isolated lungs, without increased pulmonary flow, suggests that elevated cardiac output is not required for IPAVA recruitment.

  14. Perineal hernia repair using an autologous tunica vaginalis communis in nine intact male dogs.

    Science.gov (United States)

    Pratummintra, Kittiya; Chuthatep, Suwicha; Banlunara, Wijit; Kalpravidh, Marissak

    2013-01-01

    Perineal hernia in dogs is very problematic and mostly requires surgical reconstruction of the weak pelvic diaphragm. Tissue or synthetic grafts have been used for the correction after failure of the conventional herniorrhaphy. Aim of this clinical trial was to assess the possible use of the autologous tunica vaginalis communis as a free graft for perineal hernia repair in intact male dogs. Seven unilateral and 2 bilateral perineal hernias in nine intact male dogs free from testicular and scrotal neoplasms were included in this study. The median surgical time for unilateral herniorrhaphy was 75 min. The median follow-up time was 13 months. The success of the autografting, based on no recurrence and comfort of the animals during urination and defecation, was found in ten of 11 hernias; giving a success rate of 90.91%. One hernia (9.09%) recurred 10 days after surgery. Histopathological examination of the apposing area between the graft and the adjacent tissue, taken during the repair of the recurred case at day 20, revealed neovascularization and connective tissue ingrowth. In conclusion, the tunica vaginalis autograft can be used for perineal herniorrhaphy in intact male dogs.

  15. Parkinson Disease: The Relationship Between Non-motor Symptoms and Motor Phenotype.

    Science.gov (United States)

    Ba, Fang; Obaid, Mona; Wieler, Marguerite; Camicioli, Richard; Martin, W R Wayne

    2016-03-01

    Parkinson disease (PD) presents with motor and non-motor symptoms (NMS). The NMS often precede the onset of motor symptoms, but may progress throughout the disease course. Tremor dominant, postural instability gait difficulty (PIGD), and indeterminate phenotypes can be distinguished using Unified PD Rating scales (UPDRS-III). We hypothesized that the PIGD phenotype would be more likely to develop NMS, and that the non-dopamine-responsive axial signs would correlate with NMS severity. We conducted a retrospective cross-sectional chart review to assess the relationship between NMS and PD motor phenotypes. PD patients were administered the NMS Questionnaire, the UPDRS-III, and the Mini-Mental State Examination score. The relationship between NMS burden and PD subtypes was examined using linear regression models. The prevalence of each NMS among difference PD motor subtypes was analyzed using chi-square test. PD patients with more advanced disease based on their UPDRS-III had higher NMS Questionnaire scores. The axial component of UPDRS-III correlated with higher NMS. There was no correlation between NMS and tremor scores. There was a significant correlation between PIGD score and higher NMS burden. PIGD group had higher prevalence in most NMS domains when compared with tremor dominant and indeterminate groups independent of disease duration and severity. NMS profile and severity vary according to motor phenotype. We conclude that in the PD population, patients with a PIGD phenotype who have more axial involvement, associated with advanced disease and poor motor response, have a higher risk for a higher NMS burden.

  16. System programs design of motors; Sistema de programas de diseno de motores

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Gonzalez Palomas, Oscar; Ciprian Avila, Fernando [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    This paper describes the objective of creating the program system for induction motors design SIPRODIMO, its scope, its general characteristics, its structure and the results obtained with its application, as well as the service capacity developed by the Motors Area of the Instituto de Investigaciones Elctricas. [Espanol] En este articulo se describe el objetivo de crear el sistema de programas de diseno de motores de induccion, Siprodimo, su alcance, sus caracteristicas generales, su estructura y los resultados obtenidos con su aplicacion, asi como la capacidad de servicio desarrollada por el area de motores, del Instituto de Investigaciones Electricas.

  17. Superolateral dislocation of the intact mandibular condyle associated with panfacial fracture: a case report and literature review.

    Science.gov (United States)

    Amaral, Márcio Bruno; Bueno, Sebastião Cristian; Silva, Alice Araújo Ferreira; Mesquita, Ricardo Alves

    2011-06-01

    Superolateral dislocation of the intact mandibular condyle (SDIMC) is rare. This case report focuses on a 15-year-old teenager who was involved in a motor vehicle accident as well a literature review regarding the SDIMC. Clinical examination demonstrated a diffuse edema in the midfacial area and a left lateral deflection of the mandible, including an open bite and a crepitation in the symphyseal region. Three-dimensional computed tomography scans were taken, which presented a superolateral dislocation of the left mandibular condyle as well as panfacial fracture. The patient was set in intermaxillary fixation for 2 weeks and underwent subsequent active jaw physiotherapy, the evaluation of which presented satisfactory results. This case study also presents a literature review, which demonstrated 21 well-documented cases of SDIMC. The patients' mean age was of 29 years. The male gender proved to be more prevalent, with road traffic collisions representing the most common form of accident. Type II, with unilateral dislocation, proved to be the most common. The mean reduction time was 7 days. The open methods were the most commonly used reduction methods. Mandible fracture was associated with dislocation in 82% of the cases, with other facial fractures appearing in only 23% of the cases. Patient follow up presented satisfactory results in 59% of the cases. © 2011 John Wiley & Sons A/S.

  18. Metabolism of inhaled ethane and pentane by the intact rat

    International Nuclear Information System (INIS)

    Daugherty, M.S.; Luddent, T.M.; Burk, R.F.

    1986-01-01

    Measurement of exhaled ethane or pentane is a noninvasive technique for studying in vivo lipid peroxidation. Many past studies have assumed that pentane and ethane are not metabolized. Radiolabeled ( 14 C) ethane and pentane were used to study the disposition of these compounds in intact rats. Rats were placed for 8 h in a closed plexiglass chamber fitted with a system for replenishing chamber atmospheric O 2 . Evolved CO 2 was trapped by recirculating chamber air through 3 N NaOH contained in a vessel external to the chamber. Radiolabeled ethane or pentane was injected into the chamber at the start of each experiment. The percent of 14 C-activity added to the chamber recovered in the CO 2 trap, urine, and chamber air at the end of the experiment (8 h) in the [ 14 C]-ethane (n=5) and [ 14 C]-pentane (n=4) studies are presented. Results indicate that both ethane and pentane are metabolized to CO 2 in the intact rat. Possible changes in ethane and pentane metabolism must be considered if the exhalation rates of these hydrocarbons are to be used as indices of in vivo lipid peroxidation

  19. Allergenicity, immunogenicity and dose-relationship of three intact allergen vaccines and four allergoid vaccines for subcutaneous grass pollen immunotherapy.

    Science.gov (United States)

    Henmar, H; Lund, G; Lund, L; Petersen, A; Würtzen, P A

    2008-09-01

    Different vaccines containing intact allergens or chemically modified allergoids as active ingredients are commercially available for specific immunotherapy. Allergoids are claimed to have decreased allergenicity without loss of immunogenicity and this is stated to allow administration of high allergoid doses. We compared the allergenicity and immunogenicity of four commercially available chemically modified grass pollen allergoid products with three commercially available intact grass pollen allergen vaccines. The allergenicity was investigated with immunoglobulin (Ig)E-inhibition and basophil activation assays. Human T cell proliferation and specific IgG-titres following mouse immunizations were used to address immunogenicity. Furthermore, intact allergen vaccines with different contents of active ingredients were selected to study the influence of the allergen dose. In general, a lower allergenicity for allergen vaccines was clearly linked to a reduced immunogenicity. Compared with the vaccine with the highest amount of intact allergen, the allergoids caused reduced basophil activation as well as diminished immunogenicity demonstrated by reduced T cell activation and/or reduced induction of murine grass-specific IgG antibodies. Interestingly, intact allergen vaccines with lower content of active ingredient exhibited similarly reduced allergenicity, while immunogenicity was still higher or equal to that of allergoids. The low allergenicity observed for some allergoids was inherently linked to a significantly lower immunogenic response questioning the rationale behind the chemical modification into allergoids. In addition, the linkage between allergenicity, immunogenicity and dose found for intact allergen vaccines and the immunogen as well as allergenic immune responses observed for allergoids suggest that the modified allergen vaccines do not contain high doses of immunologically active ingredients.

  20. 50 CFR 35.5 - Commercial enterprises, roads, motor vehicles, motorized equipment, motorboats, aircraft...

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Commercial enterprises, roads, motor... Rules § 35.5 Commercial enterprises, roads, motor vehicles, motorized equipment, motorboats, aircraft... private rights, there shall be no commercial enterprise and no permanent road within a wilderness unit...

  1. Control of non-conventional synchronous motors

    CERN Document Server

    Louis, Jean-Paul

    2013-01-01

    Classical synchronous motors are the most effective device to drive industrial production systems and robots with precision and rapidity. However, numerous applications require efficient controls in non-conventional situations. Firstly, this is the case with synchronous motors supplied by thyristor line-commutated inverters, or with synchronous motors with faults on one or several phases. Secondly, many drive systems use non-conventional motors such as polyphase (more than three phases) synchronous motors, synchronous motors with double excitation, permanent magnet linear synchronous motors,

  2. The correlation between motor impairments and event-related desynchronization during motor imagery in ALS patients

    Directory of Open Access Journals (Sweden)

    Kasahara Takashi

    2012-06-01

    Full Text Available Abstract Background The event-related desynchronization (ERD in EEG is known to appear during motor imagery, and is thought to reflect cortical processing for motor preparation. The aim of this study is to examine the modulation of ERD with motor impairment in ALS patients. ERD during hand motor imagery was obtained from 8 ALS patients with a variety of motor impairments. ERD was also obtained from age-matched 11 healthy control subjects with the same motor task. The magnitude and frequency of ERD were compared between groups for characterization of ALS specific changes. Results The ERD of ALS patients were significantly smaller than those of control subjects. Bulbar function and ERD were negatively correlated in ALS patients. Motor function of the upper extremities did was uncorrelated with ERD. Conclusions ALS patients with worsened bulbar scales may show smaller ERD. Motor function of the upper extremities did was uncorrelated with ERD.

  3. Spinal Accessory Motor Neurons in the Mouse: A Special Type of Branchial Motor Neuron?

    Science.gov (United States)

    Watson, Charles; Tvrdik, Petr

    2018-04-16

    The spinal accessory nerve arises from motor neurons in the upper cervical spinal cord. The axons of these motor neurons exit dorsal to the ligamentum denticulatum and form the spinal accessory nerve. The nerve ascends in the spinal subarachnoid space to enter the posterior cranial fossa through the foramen magnum. The spinal accessory nerve then turns caudally to exit through the jugular foramen alongside the vagus and glossopharyngeal nerves, and then travels to supply the sternomastoid and trapezius muscles in the neck. The unusual course of the spinal accessory nerve has long prompted speculation that it is not a typical spinal motor nerve and that it might represent a caudal remnant of the branchial motor system. Our cell lineage tracing data, combined with images from public databases, show that the spinal accessory motor neurons in the mouse transiently express Phox2b, a transcription factor that is required for development of brain stem branchial motor nuclei. While this is strong prima facie evidence that the spinal accessory motor neurons should be classified as branchial motor, the evolutionary history of these motor neurons in anamniote vertebrates suggests that they may be considered to be an atypical branchial group that possesses both branchial and somatic characteristics. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

  4. 3D visualization of movements can amplify motor cortex activation during subsequent motor imagery

    Directory of Open Access Journals (Sweden)

    Teresa eSollfrank

    2015-08-01

    Full Text Available A repetitive movement practice by motor imagery (MI can influence motor cortical excitability in the electroencephalogram (EEG. The feedback and the feedback environment should be inherently motivating and relevant for the learner and should have an appeal of novelty, real-world relevance or aesthetic value (Ryan and Deci, 2000; Merrill, 2007. This study investigated if a realistic visualization in 3D of upper and lower limb movements can amplify motor related potentials during motor imagery. We hypothesized that a richer sensory visualization might be more effective during instrumental conditioning, resulting in a more pronounced event related desynchronisation (ERD of the upper alpha band (10-12 Hz over the sensorimotor cortices thereby potentially improving MI based BCI protocols for motor rehabilitation. The results show a strong increase of the characteristic patterns of ERD of the upper alpha band components for left and right limb motor imagery present over the sensorimotor areas in both visualization conditions. Overall, significant differences were observed as a function of visualization modality (2D vs. 3D. The largest upper alpha band power decrease was obtained during motor imagery after a 3-dimensional visualization. In total in 12 out of 20 tasks the end-user of the 3D visualization group showed an enhanced upper alpha ERD relative to 2D visualization modality group, with statistical significance in nine tasks.With a realistic visualization of the limb movements, we tried to increase motor cortex activation during MI. Realistic visual feedback, consistent with the participant’s motor imagery, might be helpful for accomplishing successful motor imagery and the use of such feedback may assist in making BCI a more natural interface for motor imagery based BCI rehabilitation.

  5. LTP-like plasticity in the visual system and in the motor system appear related in young and healthy subjects

    Directory of Open Access Journals (Sweden)

    Stefan eKlöppel

    2015-09-01

    Full Text Available LTP-like plasticity measured by visual evoked potentials (VEP can be induced in the intact human brain by presenting checkerboard reversals. Also associated with LTP-like plasticity, around two third of participants respond to transcranial magnetic stimulation with a paired-associate stimulation (PAS protocol with a potentiation of their motor evoked potentials. LTP-like processes are also required for verbal and motor learning tasks. We compared effect sizes, responder rates and intercorrelations as well as the potential influence of attention between these four assessments in a group of 37 young and healthy volunteers. We observed a potentiation effect of the N75 and P100 VEP component which positively correlated with plasticity induced by PAS. Subjects with a better subjective alertness were more likely to show PAS and VEP potentiation. No correlation was found between the other assessments. Effect sizes and responder rates of VEP potentiation were higher compared to PAS. Our results indicate a high variability of LTP-like effects and no evidence for a system-specific nature. As a consequence, studies wishing to assess individual levels of LTP-like plasticity should employ a combination of multiple assessments.

  6. Operative findings of conductive hearing loss with intact tympanic membrane and normal temporal bone computed tomography.

    Science.gov (United States)

    Kim, Se-Hyung; Cho, Yang-Sun; Kim, Hye Jeong; Kim, Hyung-Jin

    2014-06-01

    Despite recent technological advances in diagnostic methods including imaging technology, it is often difficult to establish a preoperative diagnosis of conductive hearing loss (CHL) in patients with an intact tympanic membrane (TM). Especially, in patients with a normal temporal bone computed tomography (TBCT), preoperative diagnosis is more difficult. We investigated middle ear disorders encountered in patients with CHL involving an intact TM and normal TBCT. We also analyzed the surgical results with special reference to the pathology. We reviewed the medical records of 365 patients with intact TM, who underwent exploratory tympanotomy for CHL. Fifty nine patients (67 ears, eight bilateral surgeries) had a normal preoperative TBCT findings reported by neuro-radiologists. Demographic data, otologic history, TM findings, preoperative imaging findings, intraoperative findings, and pre- and postoperative audiologic data were obtained and analyzed. Exploration was performed most frequently in the second and fifth decades. The most common postoperative diagnosis was stapedial fixation with non-progressive hearing loss. The most commonly performed hearing-restoring procedure was stapedotomy with piston wire prosthesis insertion. Various types of hearing-restoring procedures during exploration resulted in effective hearing improvement, especially with better outcome in the ossicular chain fixation group. In patients with CHL who have intact TM and normal TBCT, we should consider an exploratory tympanotomy for exact diagnosis and hearing improvement. Information of the common operative findings from this study may help in preoperative counseling.

  7. Hybrid vehicle motor alignment

    Science.gov (United States)

    Levin, Michael Benjamin

    2001-07-03

    A rotor of an electric motor for a motor vehicle is aligned to an axis of rotation for a crankshaft of an internal combustion engine having an internal combustion engine and an electric motor. A locator is provided on the crankshaft, a piloting tool is located radially by the first locator to the crankshaft. A stator of the electric motor is aligned to a second locator provided on the piloting tool. The stator is secured to the engine block. The rotor is aligned to the crankshaft and secured thereto.

  8. Motor imagery beyond the motor repertoire: Activity in the primary visual cortex during kinesthetic motor imagery of difficult whole body movements.

    Science.gov (United States)

    Mizuguchi, N; Nakata, H; Kanosue, K

    2016-02-19

    To elucidate the neural substrate associated with capabilities for kinesthetic motor imagery of difficult whole-body movements, we measured brain activity during a trial involving both kinesthetic motor imagery and action observation as well as during a trial with action observation alone. Brain activity was assessed with functional magnetic resonance imaging (fMRI). Nineteen participants imagined three types of whole-body movements with the horizontal bar: the giant swing, kip, and chin-up during action observation. No participant had previously tried to perform the giant swing. The vividness of kinesthetic motor imagery as assessed by questionnaire was highest for the chin-up, less for the kip and lowest for the giant swing. Activity in the primary visual cortex (V1) during kinesthetic motor imagery with action observation minus that during action observation alone was significantly greater in the giant swing condition than in the chin-up condition within participants. Across participants, V1 activity of kinesthetic motor imagery of the kip during action observation minus that during action observation alone was negatively correlated with vividness of the kip imagery. These results suggest that activity in V1 is dependent upon the capability of kinesthetic motor imagery for difficult whole-body movements. Since V1 activity is likely related to the creation of a visual image, we speculate that visual motor imagery is recruited unintentionally for the less vivid kinesthetic motor imagery of difficult whole-body movements. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Enhanced Multisensory Integration and Motor Reactivation after Active Motor Learning of Audiovisual Associations

    Science.gov (United States)

    Butler, Andrew J.; James, Thomas W.; James, Karin Harman

    2011-01-01

    Everyday experience affords us many opportunities to learn about objects through multiple senses using physical interaction. Previous work has shown that active motor learning of unisensory items enhances memory and leads to the involvement of motor systems during subsequent perception. However, the impact of active motor learning on subsequent…

  10. Electric Motor Thermal Management

    Energy Technology Data Exchange (ETDEWEB)

    Bennion, Kevin S [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-01

    Thermal management enables more efficient and cost-effective motors. This Annual Merit Review presentation describes the technical accomplishments and progress in electric motor thermal management R&D over the last year. This project supports a broad industry demand for data, analysis methods, and experimental techniques to improve and better understand motor thermal management.

  11. Motor areas of the frontal cortex in patients with motor eloquent brain lesions.

    Science.gov (United States)

    Bulubas, Lucia; Sabih, Jamil; Wohlschlaeger, Afra; Sollmann, Nico; Hauck, Theresa; Ille, Sebastian; Ringel, Florian; Meyer, Bernhard; Krieg, Sandro M

    2016-12-01

    OBJECTIVE Because of its huge clinical potential, the importance of premotor areas for motor function itself and plastic reshaping due to tumors or ischemic brain lesions has received increased attention. Thus, in this study the authors used navigated transcranial magnetic stimulation (nTMS) to investigate whether tumorous brain lesions induce a change in motor cortex localization in the human brain. METHODS Between 2010 and 2013, nTMS motor mapping was performed in a prospective cohort of 100 patients with brain tumors in or adjacent to the rolandic cortex. Spatial data analysis was performed by normalization of the individual motor maps and creation of overlays according to tumor location. Analysis of motor evoked potential (MEP) latencies was performed regarding mean overall latencies and potentially polysynaptic latencies, defined as latencies longer than 1 SD above the mean value. Hemispheric dominance, lesion location, and motor-function deficits were also considered. RESULTS Graphical analysis showed that motor areas were not restricted to the precentral gyrus. Instead, they spread widely in the anterior-posterior direction. An analysis of MEP latency showed that mean MEP latencies were shortest in the precentral gyrus and longest in the superior and middle frontal gyri. The percentage of latencies longer than 1 SD differed widely across gyri. The dominant hemisphere showed a greater number of longer latencies than the nondominant hemisphere (p < 0.0001). Moreover, tumor location-dependent changes in distribution of polysynaptic latencies were observed (p = 0.0002). Motor-function deficit did not show any statistically significant effect. CONCLUSIONS The distribution of primary and polysynaptic motor areas changes in patients with brain tumors and highly depends on tumor location. Thus, these data should be considered for resection planning.

  12. Skeletal maturation, fundamental motor skills and motor performance in preschool children.

    Science.gov (United States)

    Freitas, D L; Lausen, B; Maia, J A; Gouveia, É R; Antunes, A M; Thomis, M; Lefevre, J; Malina, R M

    2018-06-01

    Relationships among skeletal age (SA), body size and fundamental motor skills (FMS) and motor performance were considered in 155 boys and 159 girls 3-6 years of age. Stature and body mass were measured. SA of the hand-wrist was assessed with the Tanner-Whitehouse II 20 bone method. The Test of Gross Motor Development, 2 nd edition (TGMD-2) and the Preschool Test Battery were used, respectively, to assess FMS and motor performance. Based on hierarchical regression analyses, the standardized residuals of SA on chronological age (SAsr) explained a maximum of 6.1% of the variance in FMS and motor performance in boys (ΔR 2 3 , range 0.0% to 6.1%) and a maximum of 20.4% of the variance in girls (ΔR 2 3 , range 0.0% to 20.4%) over that explained by body size and interactions of SAsr with body size (step 3). The interactions of the SAsr and stature and body mass (step 2) explained a maximum of 28.3% of the variance in boys (ΔR 2 2 , range 0.5% to 28.3%) and 16.7% of the variance in girls (ΔR 2 2 , range 0.7% to 16.7%) over that explained by body size alone. With the exception of balance, relationships among SAsr and FMS or motor performance differed between boys and girls. Overall, SA per se or interacting with body size had a relatively small influence in FMS and motor performance in children 3-6 years of age. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. 76 FR 10396 - New United Motor Manufacturing, Inc., Formerly a Joint Venture of General Motors Corporation and...

    Science.gov (United States)

    2011-02-24

    ... Manufacturing, Inc., Formerly a Joint Venture of General Motors Corporation and Toyota Motor Corporation, Including On- Site Leased Workers From Corestaff, ABM Janitorial, Toyota Engineering and Manufacturing North... Motor Manufacturing, Inc., formerly a joint venture of General Motors Corporation and Toyota Motor...

  14. Increased motor cortex excitability during motor imagery in brain-computer interface trained subjects

    Science.gov (United States)

    Mokienko, Olesya A.; Chervyakov, Alexander V.; Kulikova, Sofia N.; Bobrov, Pavel D.; Chernikova, Liudmila A.; Frolov, Alexander A.; Piradov, Mikhail A.

    2013-01-01

    Background: Motor imagery (MI) is the mental performance of movement without muscle activity. It is generally accepted that MI and motor performance have similar physiological mechanisms. Purpose: To investigate the activity and excitability of cortical motor areas during MI in subjects who were previously trained with an MI-based brain-computer interface (BCI). Subjects and Methods: Eleven healthy volunteers without neurological impairments (mean age, 36 years; range: 24–68 years) were either trained with an MI-based BCI (BCI-trained, n = 5) or received no BCI training (n = 6, controls). Subjects imagined grasping in a blocked paradigm task with alternating rest and task periods. For evaluating the activity and excitability of cortical motor areas we used functional MRI and navigated transcranial magnetic stimulation (nTMS). Results: fMRI revealed activation in Brodmann areas 3 and 6, the cerebellum, and the thalamus during MI in all subjects. The primary motor cortex was activated only in BCI-trained subjects. The associative zones of activation were larger in non-trained subjects. During MI, motor evoked potentials recorded from two of the three targeted muscles were significantly higher only in BCI-trained subjects. The motor threshold decreased (median = 17%) during MI, which was also observed only in BCI-trained subjects. Conclusion: Previous BCI training increased motor cortex excitability during MI. These data may help to improve BCI applications, including rehabilitation of patients with cerebral palsy. PMID:24319425

  15. Increased motor cortex excitability during motor imagery in brain-computer interface trained subjects

    Directory of Open Access Journals (Sweden)

    Olesya eMokienko

    2013-11-01

    Full Text Available Background: Motor imagery (MI is the mental performance of movement without muscle activity. It is generally accepted that MI and motor performance have similar physiological mechanisms.Purpose: To investigate the activity and excitability of cortical motor areas during MI in subjects who were previously trained with an MI-based brain-computer interface (BCI.Subjects and methods: Eleven healthy volunteers without neurological impairments (mean age, 36 years; range: 24–68 years were either trained with an MI-based BCI (BCI-trained, n = 5 or received no BCI training (n = 6, controls. Subjects imagined grasping in a blocked paradigm task with alternating rest and task periods. For evaluating the activity and excitability of cortical motor areas we used functional MRI and navigated transcranial magnetic stimulation (nTMS.Results: fMRI revealed activation in Brodmann areas 3 and 6, the cerebellum, and the thalamus during MI in all subjects. The primary motor cortex was activated only in BCI-trained subjects. The associative zones of activation were larger in non-trained subjects. During MI, motor evoked potentials recorded from two of the three targeted muscles were significantly higher only in BCI-trained subjects. The motor threshold decreased (median = 17% during MI, which was also observed only in BCI-trained subjects.Conclusion: Previous BCI training increased motor cortex excitability during MI. These data may help to improve BCI applications, including rehabilitation of patients with cerebral palsy.

  16. Crystallization and preliminary X-ray analysis of a C-terminal fragment of FlgJ, a putative flagellar rod cap protein from Salmonella

    International Nuclear Information System (INIS)

    Kikuchi, Yuki; Matsunami, Hideyuki; Yamane, Midori; Imada, Katsumi; Namba, Keiichi

    2008-01-01

    A C-terminal fragment of Salmonella FlgJ, FlgJ 120–316 , which has peptidoglycan-hydrolysing activity, has been overproduced, purified and crystallized and the crystals have been characterized by X-ray diffraction. The formation of the bacterial flagellar axial structure, including the filament, the hook and the rod, requires the attachment of a cap complex to the distal end of the growing structure. Because the rod penetrates the peptidoglycan (PG) layer, the rod cap complex is thought to have PG-hydrolyzing activity. FlgJ is a putative rod cap protein whose C-terminal region shows sequence similarity to known muramidases. In this study, FlgJ 120–316 , a C-terminal fragment of FlgJ which contains the muramidase region, was overproduced, purified and crystallized. Crystals were obtained by the sitting-drop vapour-diffusion technique using PEG 3350 as a crystallizing agent and belonged to the orthorhombic space group P2 1 2 1 2 1 , with unit-cell parameters a = 38.8, b = 43.9, c = 108.5 Å. Anomalous difference Patterson maps calculated from the diffraction data set of a selenomethionine-labelled crystal showed significant peaks in the Harker sections, indicating that the data were suitable for structure determination

  17. Human skin penetration of silver nanoparticles through intact and damaged skin

    International Nuclear Information System (INIS)

    Larese, Francesca Filon; D'Agostin, Flavia; Crosera, Matteo; Adami, Gianpiero; Renzi, Nadia; Bovenzi, Massimo; Maina, Giovanni

    2009-01-01

    There is a growing interest on nanoparticle safety for topical use. The benefits of nanoparticles have been shown in several scientific fields, but little is known about their potential to penetrate the skin. This study aims at evaluating in vitro skin penetration of silver nanoparticles. Experiments were performed using the Franz diffusion cell method with intact and damaged human skin. Physiological solution was used as receiving phase and 70 μg/cm 2 of silver nanoparticles coated with polyvinylpirrolidone dispersed in synthetic sweat were applied as donor phase to the outer surface of the skin for 24 h. The receptor fluid measurements were performed by electro thermal atomic absorption spectroscopy (ETAAS). Human skin penetration was also determined by using transmission electron microscope (TEM) to verify the location of silver nanoparticles in exposed membranes. Median silver concentrations of 0.46 ng cm -2 (range -2 (range 0.43-11.6) were found in the receiving solutions of cells where the nanoparticles solution was applied on intact skin (eight cells) and on damaged skin (eight cells), respectively. Twenty-four hours silver flux permeation in damaged skin was 0.62 ± 0.2 ng cm -2 with a lag time <1 h. Our experimental data showed that silver nanoparticles absorption through intact and damaged skin was very low but detectable, and that in case of damaged skin it was possible an increasing permeation of silver applied as nanoparticles. Moreover, silver nanoparticles could be detected in the stratum corneum and the outermost surface of the epidermis by electron microscopy. We demonstrated for the first time that silver applied as nanoparticles coated with polyvinylpirrolidone is able to permeate the damaged skin in an in vitro diffusion cell system

  18. Spatially Rearranged Object Parts Can Facilitate Perception of Intact Whole Objects

    Directory of Open Access Journals (Sweden)

    Laura eCacciamani

    2014-05-01

    Full Text Available The familiarity of an object depends on the spatial arrangement of its parts; when the parts are spatially rearranged, they form a novel, unrecognizable configuration. Yet the same collection of parts comprises both the familiar and novel configuration. Is it possible that the collection of familiar parts activates a representation of the intact familiar configuration even when they are spatially rearranged? We presented novel configurations as primes before test displays that assayed effects on figure-ground perception from memories of intact familiar objects. In our test displays, two equal-area regions shared a central border; one region depicted a portion of a familiar object. Previous research with such displays has shown that participants are more likely to perceive the region depicting a familiar object as the figure and the abutting region as its ground when the familiar object is depicted in its upright orientation rather than upside down. The novel primes comprised either the same or a different collection of parts as the familiar object in the test display (part-rearranged and control primes, respectively. We found that participants were more likely to perceive the familiar region as figure in upright vs. inverted displays following part-rearranged primes but not control primes. Thus, priming with a novel configuration comprising the same familiar parts as the upcoming figure-ground display facilitated orientation-dependent effects of object memories on figure assignment. Similar results were obtained when the spatially rearranged collection of parts was suggested on the groundside of the prime’s border, suggesting that familiar parts in novel configurations access the representation of their corresponding intact whole object before figure assignment. These data demonstrate that familiar parts access memories of familiar objects even when they are arranged in a novel configuration.

  19. Spatially rearranged object parts can facilitate perception of intact whole objects.

    Science.gov (United States)

    Cacciamani, Laura; Ayars, Alisabeth A; Peterson, Mary A

    2014-01-01

    The familiarity of an object depends on the spatial arrangement of its parts; when the parts are spatially rearranged, they form a novel, unrecognizable configuration. Yet the same collection of parts comprises both the familiar and novel configuration. Is it possible that the collection of familiar parts activates a representation of the intact familiar configuration even when they are spatially rearranged? We presented novel configurations as primes before test displays that assayed effects on figure-ground perception from memories of intact familiar objects. In our test displays, two equal-area regions shared a central border; one region depicted a portion of a familiar object. Previous research with such displays has shown that participants are more likely to perceive the region depicting a familiar object as the figure and the abutting region as its ground when the familiar object is depicted in its upright orientation rather than upside down. The novel primes comprised either the same or a different collection of parts as the familiar object in the test display (part-rearranged and control primes, respectively). We found that participants were more likely to perceive the familiar region as figure in upright vs. inverted displays following part-rearranged primes but not control primes. Thus, priming with a novel configuration comprising the same familiar parts as the upcoming figure-ground display facilitated orientation-dependent effects of object memories on figure assignment. Similar results were obtained when the spatially rearranged collection of parts was suggested on the groundside of the prime's border, suggesting that familiar parts in novel configurations access the representation of their corresponding intact whole object before figure assignment. These data demonstrate that familiar parts access memories of familiar objects even when they are arranged in a novel configuration.

  20. Synchronous motor with soft start element formed between the motor rotor and motor output shaft to successfully synchronize loads that have high inertia and/or high torque

    Science.gov (United States)

    Umans, Stephen D; Nisley, Donald L; Melfi, Michael J

    2014-10-28

    A line-start synchronous motor has a housing, a rotor shaft, and an output shaft. A soft-start coupling portion is operatively coupled to the output shaft and the rotor shaft. The soft-start coupling portion is configurable to enable the synchronous motor to obtain synchronous operation and to drive, at least near synchronous speed during normal steady state operation of the motor, a load having characteristics sufficient to prevent obtaining normal synchronous operation of the motor when the motor is operatively connected to the load in the absence of the soft-start coupling. The synchronous motor is sufficiently rated to obtain synchronous operation and to drive, at least near synchronous speed during normal steady state operation of the motor, a load having characteristics sufficient to prevent obtaining normal synchronous operation of the motor when the motor is operatively connected to the load in the absence of the soft-start coupling.

  1. Spectrophotometric Evaluation of the Pulpal Peroxide Levels in Intact and Restored Teeth - An Invitro Study.

    Science.gov (United States)

    Patri, Gaurav; Acharya, Gourismita; Agrawal, Pratik; Panda, Vijeta

    2016-08-01

    Hydrogen peroxide (30%) is a commonly used "in office" bleaching agent. Deleterious effects of hydrogen peroxide on the pulp have been observed. The present study was conducted with the aim to evaluate the penetration of 30% hydrogen peroxide into the pulp chamber through intact teeth and through the surface of teeth, restored with either hybrid composite or Resin Modified Glass Ionomer Cement (RMGIC). Sixty extracted human maxillary central incisors were selected and divided into six groups. Two groups were restored with hybrid composite resin and two with RMGIC, while two groups were left intact. The teeth with acetate buffer solution in their pulp cavity were then immersed in either 30% hydrogen peroxide or distilled water depending upon the group, for 60 minutes at 37°C. Then horseradish peroxidase and leucocrystal violet were added to the acetate buffer solution present in the pulp chamber after it was transferred to a test tube and the optical density of the resultant blue solution obtained was measured spectrophotometrically. The data obtained were analyzed using one way ANOVA and Student's t-test. The data obtained established that hydrogen peroxide penetrated into the pulp from the bleaching agent used. Hydrogen peroxide (30%) showed the highest pulpal peroxide level in teeth restored with RMGIC followed by teeth restored with hybrid composite resin and the least amount of penetration was observed in intact teeth. The amount of peroxide penetration into the tooth is more through restored tooth than intact tooth and is also dependant on the type of restorative materials used.

  2. The relationships between self-transcendence and spiritual well-being in cognitively intact nursing home patients.

    Science.gov (United States)

    Haugan, Gørill; Rannestad, Toril; Hammervold, Randi; Garåsen, Helge; Espnes, Geir A

    2014-03-01

    Self-transcendence is considered a developmental process of personal maturity and a vital resource of well-being in later adulthood. Measurement of the associations between self-transcendence and spiritual well-being in cognitively intact nursing home patients has not been previously published. The aim of this study was to identify the relationships between self-transcendence and spiritual well-being in cognitively intact nursing home patients. A cross-sectional design using the self-transcendence scale and the FACIT-Sp spiritual well-being questionnaire was adopted. A sample of 202 cognitively intact nursing home patients in mid-Norway was selected to respond to the questionnaires in 2008 and 2009. Statistical analyses were conducted using lisrel 8.8 (Scientific Software International, Chicago, IL, USA) and structural equation modelling. A hypothesised structural equation model comprising a two-factor construct of self-transcendence and a three-factor construct of spiritual well-being demonstrated significant direct relationships between self-transcendence and spiritual well-being and total effects of self-transcendence on spiritual well-being. Facilitating patients' self-transcendence, both interpersonally and intrapersonally, might increase spiritual well-being among cognitively intact nursing home patients, which is seen to be of great importance to nursing home patients' overall satisfaction and satisfaction with staff. The two-factor construct of self-transcendence and the three-factor construct of FACIT-Sp allow a more complex examination of the associations between the constructs and prove more specific guidelines for nursing interventions promoting well-being in nursing home patients. © 2013 Blackwell Publishing Ltd.

  3. Analysis of activity and motor coordination in rats undergoing stereotactic surgery and implantation of a cannula into the dorsal hippocampus.

    Science.gov (United States)

    Hernández-López, F; Rodríguez-Landa, J F; Puga-Olguín, A; Germán-Ponciano, L J; Rivadeneyra-Domínguez, E; Bernal-Morales, B

    Stereotactic surgery is used to place electrodes or cannulas in the brain in order to study the function of several brain structures in preclinical research. The hippocampus has been extensively studied with this methodology due to its involvement in a wide range of neurological, cognitive, emotional, and affective disorders. However, the effects of stereotactic surgery on coordination and motor activity should be evaluated in order to determine whether this surgical procedure causes any neurological alterations that may bias the results of studies incorporating this technique. We evaluated the effects of stereotactic surgery and implantation of a cannula into the hippocampus of female Wistar rats on the motor activity, forced swim, and rotarod tests. The stage of the oestrous cycle was included in the statistical analysis. Stereotactic surgery had no impact on any of the motor activity variables assessed in the open field (squares crossed, time spent in grooming, and rearing), forced swim (turning behaviour, lateral swimming, latency to first immobility, and time spent immobile), and rotarod (latency to fall) tests, compared with intact rats. Regardless of surgical manipulation, rats in the metestrus and diestrus stages crossed a greater number of squares and displayed longer immobility times than those in the proestrus and estrus stages. Stereotactic surgery for cannula placement in the dorsal hippocampus does not affect coordination and motor activity in rats. We can therefore conclude that this procedure has no neurological complications that may interfere in the interpretation of results of studies applying this technique. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Programmable dc motor controller

    Science.gov (United States)

    Hopwood, J. E.

    1982-11-01

    A portable programmable dc motor controller, with features not available on commercial instruments was developed for controlling fixtures during welding processes. The controller can be used to drive any dc motor having tachometer feedback and motor requirements not exceeding 30 volts, 3 amperes. Among the controller's features are delayed start time, upslope time, speed, and downslope time.

  5. 75 FR 26794 - New United Motor Manufacturing, Inc., Formerly a Joint Venture of General Motors Corporation and...

    Science.gov (United States)

    2010-05-12

    ... Manufacturing, Inc., Formerly a Joint Venture of General Motors Corporation and Toyota Motor Corporation... United Motor Manufacturing, Inc., formerly a joint venture of General Motors Corporation and Toyota Motor... reviewed the certification for workers of the subject firm. The workers assemble the Toyota Corolla and the...

  6. Differential effects of androgens on coronary blood flow regulation and arteriolar diameter in intact and castrated swine

    Directory of Open Access Journals (Sweden)

    O’Connor Erin K

    2012-05-01

    Full Text Available Abstract Background Low endogenous testosterone levels have been shown to be a risk factor for the development of cardiovascular disease and cardiovascular benefits associated with testosterone replacement therapy are being advocated; however, the effects of endogenous testosterone levels on acute coronary vasomotor responses to androgen administration are not clear. The objective of this study was to compare the effects of acute androgen administration on in vivo coronary conductance and in vitro coronary microvascular diameter in intact and castrated male swine. Methods Pigs received intracoronary infusions of physiologic levels (1–100 nM of testosterone, the metabolite 5α-dihydrotestosterone, and the epimer epitestosterone while left anterior descending coronary blood flow and mean arterial pressure were continuously monitored. Following sacrifice, coronary arterioles were isolated, cannulated, and exposed to physiologic concentrations (1–100 nM of testosterone, 5α-dihydrotestosterone, and epitestosterone. To evaluate effects of the androgen receptor on acute androgen dilation responses, real-time PCR and immunohistochemistry for androgen receptor were performed on conduit and resistance coronary vessels. Results In vivo, testosterone and 5α-dihydrotestosterone produced greater increases in coronary conductance in the intact compared to the castrated males. In vitro, percent maximal dilation of microvessels was similar between intact and castrated males for testosterone and 5α-dihydrotestosterone. In both studies epitestosterone produced significant increases in conductance and microvessel diameter from baseline in the intact males. Androgen receptor mRNA expression and immunohistochemical staining were similar in intact and castrated males. Conclusions Acute coronary vascular responses to exogenous androgen administration are increased by endogenous testosterone, an effect unrelated to changes in androgen receptor expression.

  7. Motor-sensory confluence in tactile perception.

    Science.gov (United States)

    Saig, Avraham; Gordon, Goren; Assa, Eldad; Arieli, Amos; Ahissar, Ehud

    2012-10-03

    Perception involves motor control of sensory organs. However, the dynamics underlying emergence of perception from motor-sensory interactions are not yet known. Two extreme possibilities are as follows: (1) motor and sensory signals interact within an open-loop scheme in which motor signals determine sensory sampling but are not affected by sensory processing and (2) motor and sensory signals are affected by each other within a closed-loop scheme. We studied the scheme of motor-sensory interactions in humans using a novel object localization task that enabled monitoring the relevant overt motor and sensory variables. We found that motor variables were dynamically controlled within each perceptual trial, such that they gradually converged to steady values. Training on this task resulted in improvement in perceptual acuity, which was achieved solely by changes in motor variables, without any change in the acuity of sensory readout. The within-trial dynamics is captured by a hierarchical closed-loop model in which lower loops actively maintain constant sensory coding, and higher loops maintain constant sensory update flow. These findings demonstrate interchangeability of motor and sensory variables in perception, motor convergence during perception, and a consistent hierarchical closed-loop perceptual model.

  8. How thoughts give rise to action - conscious motor intention increases the excitability of target-specific motor circuits.

    Directory of Open Access Journals (Sweden)

    Volker R Zschorlich

    Full Text Available The present study shows evidence for conscious motor intention in motor preparation prior to movement execution. We demonstrate that conscious motor intention of directed movement, combined with minimally supra-threshold transcranial magnetic stimulation (TMS of the motor cortex, determines the direction and the force of resulting movements, whilst a lack of intention results in weak and omni-directed muscle activation. We investigated changes of consciously intended goal directed movements by analyzing amplitudes of motor-evoked potentials of the forearm muscle, flexor carpi radialis (FCR, and extensor carpi radialis (ECR, induced by transcranial magnetic stimulation over the right motor cortex and their motor outcome. Right-handed subjects were asked to develop a strong intention to move their left wrist (flexion or extension, without any overt motor output at the wrist, prior to brain stimulation. Our analyses of hand acceleration and electromyography showed that during the strong motor intention of wrist flexion movement, it evoked motor potential responses that were significantly larger in the FCR muscle than in the ECR, whilst the opposite was true for an extension movement. The acceleration data on flexion/extension corresponded to this finding. Under no-intention conditions again, which served as a reference for motor evoked potentials, brain stimulation resulted in undirected and minimally simultaneous extension/flexion innervation and virtually no movement. These results indicate that conscious intentions govern motor function, which in turn shows that a neuronal activation representing an "intention network" in the human brain pre-exists, and that it functionally represents target specific motor circuits. Until today, it was unclear whether conscious motor intention exists prior to movement, or whether the brain constructs such an intention after movement initiation. Our study gives evidence that motor intentions become aware before

  9. How Thoughts Give Rise to Action - Conscious Motor Intention Increases the Excitability of Target-Specific Motor Circuits

    Science.gov (United States)

    Zschorlich, Volker R.; Köhling, Rüdiger

    2013-01-01

    The present study shows evidence for conscious motor intention in motor preparation prior to movement execution. We demonstrate that conscious motor intention of directed movement, combined with minimally supra-threshold transcranial magnetic stimulation (TMS) of the motor cortex, determines the direction and the force of resulting movements, whilst a lack of intention results in weak and omni-directed muscle activation. We investigated changes of consciously intended goal directed movements by analyzing amplitudes of motor-evoked potentials of the forearm muscle, flexor carpi radialis (FCR), and extensor carpi radialis (ECR), induced by transcranial magnetic stimulation over the right motor cortex and their motor outcome. Right-handed subjects were asked to develop a strong intention to move their left wrist (flexion or extension), without any overt motor output at the wrist, prior to brain stimulation. Our analyses of hand acceleration and electromyography showed that during the strong motor intention of wrist flexion movement, it evoked motor potential responses that were significantly larger in the FCR muscle than in the ECR, whilst the opposite was true for an extension movement. The acceleration data on flexion/extension corresponded to this finding. Under no-intention conditions again, which served as a reference for motor evoked potentials, brain stimulation resulted in undirected and minimally simultaneous extension/flexion innervation and virtually no movement. These results indicate that conscious intentions govern motor function, which in turn shows that a neuronal activation representing an “intention network” in the human brain pre-exists, and that it functionally represents target specific motor circuits. Until today, it was unclear whether conscious motor intention exists prior to movement, or whether the brain constructs such an intention after movement initiation. Our study gives evidence that motor intentions become aware before any motor

  10. Functional connectivity between somatosensory and motor brain areas predicts individual differences in motor learning by observing.

    Science.gov (United States)

    McGregor, Heather R; Gribble, Paul L

    2017-08-01

    Action observation can facilitate the acquisition of novel motor skills; however, there is considerable individual variability in the extent to which observation promotes motor learning. Here we tested the hypothesis that individual differences in brain function or structure can predict subsequent observation-related gains in motor learning. Subjects underwent an anatomical MRI scan and resting-state fMRI scans to assess preobservation gray matter volume and preobservation resting-state functional connectivity (FC), respectively. On the following day, subjects observed a video of a tutor adapting her reaches to a novel force field. After observation, subjects performed reaches in a force field as a behavioral assessment of gains in motor learning resulting from observation. We found that individual differences in resting-state FC, but not gray matter volume, predicted postobservation gains in motor learning. Preobservation resting-state FC between left primary somatosensory cortex and bilateral dorsal premotor cortex, primary motor cortex, and primary somatosensory cortex and left superior parietal lobule was positively correlated with behavioral measures of postobservation motor learning. Sensory-motor resting-state FC can thus predict the extent to which observation will promote subsequent motor learning. NEW & NOTEWORTHY We show that individual differences in preobservation brain function can predict subsequent observation-related gains in motor learning. Preobservation resting-state functional connectivity within a sensory-motor network may be used as a biomarker for the extent to which observation promotes motor learning. This kind of information may be useful if observation is to be used as a way to boost neuroplasticity and sensory-motor recovery for patients undergoing rehabilitation for diseases that impair movement such as stroke. Copyright © 2017 the American Physiological Society.

  11. Heavy metals in locus ceruleus and motor neurons in motor neuron disease.

    Science.gov (United States)

    Pamphlett, Roger; Kum Jew, Stephen

    2013-12-12

    The causes of sporadic amyotrophic lateral sclerosis (SALS) and other types of motor neuron disease (MND) remain largely unknown. Heavy metals have long been implicated in MND, and it has recently been shown that inorganic mercury selectively enters human locus ceruleus (LC) and motor neurons. We therefore used silver nitrate autometallography (AMG) to look for AMG-stainable heavy metals (inorganic mercury and bismuth) in LC and motor neurons of 24 patients with MND (18 with SALS and 6 with familial MND) and in the LC of 24 controls. Heavy metals in neurons were found in significantly more MND patients than in controls when comparing: (1) the presence of any versus no heavy metal-containing LC neurons (MND 88%, controls 42%), (2) the median percentage of heavy metal-containing LC neurons (MND 9.5%, control 0.0%), and (3) numbers of individuals with heavy metal-containing LC neurons in the upper half of the percentage range (MND 75%, controls 25%). In MND patients, 67% of remaining spinal motor neurons contained heavy metals; smaller percentages were found in hypoglossal, nucleus ambiguus and oculomotor neurons, but none in cortical motor neurons. The majority of MND patients had heavy metals in both LC and spinal motor neurons. No glia or other neurons, including neuromelanin-containing neurons of the substantia nigra, contained stainable heavy metals. Uptake of heavy metals by LC and lower motor neurons appears to be fairly common in humans, though heavy metal staining in the LC, most likely due to inorganic mercury, was seen significantly more often in MND patients than in controls. The LC innervates many cell types that are affected in MND, and it is possible that MND is triggered by toxicant-induced interactions between LC and motor neurons.

  12. Heavy metals in locus ceruleus and motor neurons in motor neuron disease

    Science.gov (United States)

    2013-01-01

    Background The causes of sporadic amyotrophic lateral sclerosis (SALS) and other types of motor neuron disease (MND) remain largely unknown. Heavy metals have long been implicated in MND, and it has recently been shown that inorganic mercury selectively enters human locus ceruleus (LC) and motor neurons. We therefore used silver nitrate autometallography (AMG) to look for AMG-stainable heavy metals (inorganic mercury and bismuth) in LC and motor neurons of 24 patients with MND (18 with SALS and 6 with familial MND) and in the LC of 24 controls. Results Heavy metals in neurons were found in significantly more MND patients than in controls when comparing: (1) the presence of any versus no heavy metal-containing LC neurons (MND 88%, controls 42%), (2) the median percentage of heavy metal-containing LC neurons (MND 9.5%, control 0.0%), and (3) numbers of individuals with heavy metal-containing LC neurons in the upper half of the percentage range (MND 75%, controls 25%). In MND patients, 67% of remaining spinal motor neurons contained heavy metals; smaller percentages were found in hypoglossal, nucleus ambiguus and oculomotor neurons, but none in cortical motor neurons. The majority of MND patients had heavy metals in both LC and spinal motor neurons. No glia or other neurons, including neuromelanin-containing neurons of the substantia nigra, contained stainable heavy metals. Conclusions Uptake of heavy metals by LC and lower motor neurons appears to be fairly common in humans, though heavy metal staining in the LC, most likely due to inorganic mercury, was seen significantly more often in MND patients than in controls. The LC innervates many cell types that are affected in MND, and it is possible that MND is triggered by toxicant-induced interactions between LC and motor neurons. PMID:24330485

  13. Electric vehicle traction motors - The development of an advanced motor concept

    Science.gov (United States)

    Campbell, P.

    1980-01-01

    An axial-field permanent magnet traction motor is described, similar to several advanced motors that are being developed in the United States. This type of machine has several advantages over conventional dc motors, particularly in the electric vehicle application. The rapidly changing cost of magnetic materials, particularly cobalt, makes it important to study the utilization of permanent magnet materials in such machines. The impact of different magnets on machine design is evaluated, and the advantages of using iron powder composites in the armature are assessed.

  14. Formation of model-free motor memories during motor adaptation depends on perturbation schedule.

    Science.gov (United States)

    Orban de Xivry, Jean-Jacques; Lefèvre, Philippe

    2015-04-01

    Motor adaptation to an external perturbation relies on several mechanisms such as model-based, model-free, strategic, or repetition-dependent learning. Depending on the experimental conditions, each of these mechanisms has more or less weight in the final adaptation state. Here we focused on the conditions that lead to the formation of a model-free motor memory (Huang VS, Haith AM, Mazzoni P, Krakauer JW. Neuron 70: 787-801, 2011), i.e., a memory that does not depend on an internal model or on the size or direction of the errors experienced during the learning. The formation of such model-free motor memory was hypothesized to depend on the schedule of the perturbation (Orban de Xivry JJ, Ahmadi-Pajouh MA, Harran MD, Salimpour Y, Shadmehr R. J Neurophysiol 109: 124-136, 2013). Here we built on this observation by directly testing the nature of the motor memory after abrupt or gradual introduction of a visuomotor rotation, in an experimental paradigm where the presence of model-free motor memory can be identified (Huang VS, Haith AM, Mazzoni P, Krakauer JW. Neuron 70: 787-801, 2011). We found that relearning was faster after abrupt than gradual perturbation, which suggests that model-free learning is reduced during gradual adaptation to a visuomotor rotation. In addition, the presence of savings after abrupt introduction of the perturbation but gradual extinction of the motor memory suggests that unexpected errors are necessary to induce a model-free motor memory. Overall, these data support the hypothesis that different perturbation schedules do not lead to a more or less stabilized motor memory but to distinct motor memories with different attributes and neural representations. Copyright © 2015 the American Physiological Society.

  15. Non-Motor Symptoms in Patients Suffering from Motor Neuron Diseases.

    Science.gov (United States)

    Günther, René; Richter, Nicole; Sauerbier, Anna; Chaudhuri, Kallol Ray; Martinez-Martin, Pablo; Storch, Alexander; Hermann, Andreas

    2016-01-01

    The recently postulated "disease spreading hypothesis" has gained much attention, especially for Parkinson's disease (PD). The various non-motor symptoms (NMS) in neurodegenerative diseases would be much better explained by this hypothesis than by the degeneration of disease-specific cell populations. Motor neuron disease (MND) is primarily known as a group of diseases with a selective loss of motor function. However, recent evidence suggests disease spreading into non-motor brain regions also in MND. The aim of this study was to comprehensively detect NMS in patients suffering from MND. We used a self-rating questionnaire including 30 different items of gastrointestinal, autonomic, neuropsychiatric, and sleep complaints [NMS questionnaire (NMSQuest)], which is an established tool in PD patients. 90 MND patients were included and compared to 96 controls. In total, MND patients reported significantly higher NMS scores (median: 7 points) in comparison to controls (median: 4 points). Dribbling, impaired taste/smelling, impaired swallowing, weight loss, loss of interest, sad/blues, falling, and insomnia were significantly more prevalent in MND patients compared to controls. Interestingly, excessive sweating was more reported in the MND group. Correlation analysis revealed an increase of total NMS score with disease progression. NMS in MND patients seemed to increase with disease progression, which would fit with the recently postulated "disease spreading hypothesis." The total NMS score in the MND group significantly exceeded the score for the control group, but only 8 of the 30 single complaints of the NMSQuest were significantly more often reported by MND patients. Dribbling, impaired swallowing, weight loss, and falling could primarily be connected to motor neuron degeneration and declared as motor symptoms in MND.

  16. Motor-operated gearbox efficiency

    International Nuclear Information System (INIS)

    DeWall, K.G.; Watkins, J.C.; Bramwell, D.; Weidenhamer, G.H.

    1996-01-01

    Researchers at the Idaho National Engineering Laboratory recently conducted tests investigating the operating efficiency of the power train (gearbox) in motor-operators typically used in nuclear power plants to power motor-operated valves. Actual efficiency ratios were determined from in-line measurements of electric motor torque (input to the operator gearbox) and valve stem torque (output from the gearbox) while the operators were subjected to gradually increasing loads until the electric motor stalled. The testing included parametric studies under reduced voltage and elevated temperature conditions. As part of the analysis of the results, the authors compared efficiency values determined from testing to the values published by the operator manufacturer and typically used by the industry in calculations for estimating motor-operator capabilities. The operators they tested under load ran at efficiencies lower than the running efficiency (typically 50%) published by the operator manufacturer

  17. Motor-operated gearbox efficiency

    Energy Technology Data Exchange (ETDEWEB)

    DeWall, K.G.; Watkins, J.C.; Bramwell, D. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Weidenhamer, G.H.

    1996-12-01

    Researchers at the Idaho National Engineering Laboratory recently conducted tests investigating the operating efficiency of the power train (gearbox) in motor-operators typically used in nuclear power plants to power motor-operated valves. Actual efficiency ratios were determined from in-line measurements of electric motor torque (input to the operator gearbox) and valve stem torque (output from the gearbox) while the operators were subjected to gradually increasing loads until the electric motor stalled. The testing included parametric studies under reduced voltage and elevated temperature conditions. As part of the analysis of the results, the authors compared efficiency values determined from testing to the values published by the operator manufacturer and typically used by the industry in calculations for estimating motor-operator capabilities. The operators they tested under load ran at efficiencies lower than the running efficiency (typically 50%) published by the operator manufacturer.

  18. Motor-operator gearbox efficiency

    International Nuclear Information System (INIS)

    DeWall, K.G.; Watkins, J.C.; Bramwell, D.

    1996-01-01

    Researchers at the Idaho National Engineering Laboratory recently conducted tests investigating the operating efficiency of the power train (gearbox) in motor-operators typically used in nuclear power plants to power motor-operated valves. Actual efficiency ratios were determined from in-line measurements of electric motor torque (input to the operator gearbox) and valve stem torque (output from the gearbox) while the operators were subjected to gradually increasing loads until the electric motor stalled. The testing included parametric studies under reduced voltage and elevated temperature conditions. As part of the analysis of the results, we compared efficiency values determined from testing to the values published by the operator manufacturer and typically used by the industry in calculations for estimating motor-operator capabilities. The operators we tested under load ran at efficiencies lower than the running efficiency (typically 50%) published by the operator manufacturer

  19. Two-Phase Induction Motor Drives

    Directory of Open Access Journals (Sweden)

    Gholam Reza Arab Markadeh

    2010-10-01

    Full Text Available The lack of variable-speed drives for two (single induction motor is a reality. This article attempts mainly to investigate the reasons for this lack of variable – speed drives. This paper deals with literature survey of various existing converter topologies, which have been proposed for adjustable speed single phase induction motor drives. Various converter topologies have been compared in this paper. Among these converter topologies, the adjustable frequency PWM inverter is the best choice for single-phase induction motor drives. However, adjustable-frequency drives have not been widely used with single-phase Induction motors. The open-loop constant V/F control law cannot be used with the single-phase induction motor drives as it is used with three phase motors. The variation of the operating frequency at lower speed range with constant load torque causes variation in motor's slip. A constant V/F control is suitable only over the upper speed range.

  20. Echoes on the motor network: how internal motor control structures afford sensory experience.

    Science.gov (United States)

    Burgess, Jed D; Lum, Jarrad A G; Hohwy, Jakob; Enticott, Peter G

    2017-12-01

    Often, during daily experiences, hearing peers' actions can activate motor regions of the CNS. This activation is termed auditory-motor resonance (AMR) and is thought to represent an internal simulation of one's motor memories. Currently, AMR is demonstrated at the neuronal level in the Macaque and songbird, in conjunction with evidence on a systems level in humans. Here, we review evidence of AMR development from a motor control perspective. In the context of internal modelling, we consider data that demonstrates sensory-guided motor learning and action maintenance, particularly the notion of sensory comparison seen during songbird vocalisation. We suggest that these comparisons generate accurate sensory-to-motor inverse mappings. Furthermore, given reports of mapping decay after songbird learning, we highlight the proposal that the maintenance of these sensorimotor maps potentially explains why frontoparietal regions are activated upon hearing known sounds (i.e., AMR). In addition, we also recommend that activation of these types of internal models outside of action execution may provide an ecological advantage when encountering known stimuli in ambiguous conditions.

  1. Artificial molecular motors

    NARCIS (Netherlands)

    Kassem, Salma; van Leeuwen, Thomas; Lubbe, Anouk S.; Wilson, Miriam R.; Feringa, Ben L.; Leigh, David A.

    2017-01-01

    Motor proteins are nature's solution for directing movement at the molecular level. The field of artificial molecular motors takes inspiration from these tiny but powerful machines. Although directional motion on the nanoscale performed by synthetic molecular machines is a relatively new

  2. CANONICAL RELATIONS BETWEEN BASIC AND MOTOR - SITUATIONAL-MOTOR SKILLS IN SPORT GAMES

    Directory of Open Access Journals (Sweden)

    Bećir Šabotić

    2013-07-01

    Full Text Available The aim of this study was to establish the correlation between the predictor-basic motor and situational-motor tests in sports games. On the sample of 62 subjects of the first year of high school was carried out measurements which covered 12 basic and 6 motor variables and situational tests in volleyball and basketball.Based on the results of the canonical correlation analysis, it can be concluded that there is a significant relationship between the predictor variables and a set of criterion variables, situational-motor tests basketball and volleyball. These results are logical given the structure of movements from basketball and volleyball that require a high level of coordination and speed.

  3. How Kinesthetic Motor Imagery works: A predictive-processing theory of visualization in sports and motor expertise

    NARCIS (Netherlands)

    Ridderinkhof, K.R.; Brass, M.

    2015-01-01

    Kinesthetic Motor Imagery (KMI) is an important technique to acquire and refine motor skills. KMI is widely used by professional athletes as an effective way to improve motor performance without overt motor output. Despite this obvious relevance, the functional mechanisms and neural circuits

  4. 76 FR 12792 - Petition for Exemption From the Federal Motor Vehicle Motor Theft Prevention Standard; General...

    Science.gov (United States)

    2011-03-08

    ... From the Federal Motor Vehicle Motor Theft Prevention Standard; General Motors Corporation AGENCY..., Exemption from the Theft Prevention Standard. This petition is granted because the agency has determined... in reducing and deterring motor vehicle theft as compliance with the parts-marking requirements of...

  5. 77 FR 22383 - Petition for Exemption From the Federal Motor Vehicle Motor Theft Prevention Standard; TESLA

    Science.gov (United States)

    2012-04-13

    ... From the Federal Motor Vehicle Motor Theft Prevention Standard; TESLA AGENCY: National Highway Traffic... exemption. SUMMARY: This document grants in full the petition of Tesla Motors Inc's. (Tesla) for an... 49 CFR Part 541, Federal Motor Vehicle Theft Prevention Standard. Tesla requested confidential...

  6. MaLT - Combined Motor and Language Therapy Tool for Brain Injury Patients Using Kinect.

    Science.gov (United States)

    Wairagkar, Maitreyee; McCrindle, Rachel; Robson, Holly; Meteyard, Lotte; Sperrin, Malcom; Smith, Andy; Pugh, Moyra

    2017-03-23

    The functional connectivity and structural proximity of elements of the language and motor systems result in frequent co-morbidity post brain injury. Although rehabilitation services are becoming increasingly multidisciplinary and "integrated", treatment for language and motor functions often occurs in isolation. Thus, behavioural therapies which promote neural reorganisation do not reflect the high intersystem connectivity of the neurologically intact brain. As such, there is a pressing need for rehabilitation tools which better reflect and target the impaired cognitive networks. The objective of this research is to develop a combined high dosage therapy tool for language and motor rehabilitation. The rehabilitation therapy tool developed, MaLT (Motor and Language Therapy), comprises a suite of computer games targeting both language and motor therapy that use the Kinect sensor as an interaction device. The games developed are intended for use in the home environment over prolonged periods of time. In order to track patients' engagement with the games and their rehabilitation progress, the game records patient performance data for the therapist to interrogate. MaLT incorporates Kinect-based games, a database of objects and language parameters, and a reporting tool for therapists. Games have been developed that target four major language therapy tasks involving single word comprehension, initial phoneme identification, rhyme identification and a naming task. These tasks have 8 levels each increasing in difficulty. A database of 750 objects is used to programmatically generate appropriate questions for the game, providing both targeted therapy and unique gameplay every time. The design of the games has been informed by therapists and by discussions with a Public Patient Involvement (PPI) group. Pilot MaLT trials have been conducted with three stroke survivors for the duration of 6 to 8 weeks. Patients' performance is monitored through MaLT's reporting facility

  7. The effect of hepatoprotective preparations thioctacid and flavobion on histones in intact and regenerating lever in irradiated rats

    International Nuclear Information System (INIS)

    Kozhurkova, M.; Kropachova, E.; Mishurova, R.; Reksa, R.

    1992-01-01

    The changes in concentration, total content of histones and relative proportion of individual histone fractions in intact and regenerating liver were followed in rats after administration of hepatoprotective agents flavobion and thioctacid and after whole-body gamma irradiation with a dose 5.7 Gy. Thioctacid alone caused an increase in histone concentration in intact liver whereas flavobion alone did not produce significant quantitative changes. Irradiation alone decreased markedly the concentration and total content of histones in intact as well as regenerating liver of unprotected rats. Administration of thioctacid or flavobion protected from these quantitative histone changes or alleviated them consideradly. In relative proportion of individual histone fractions, the most profound changes were found in H1 histone after flavobion application

  8. [Children and motor competence].

    Science.gov (United States)

    Sigmundsson, H; Haga, M

    2000-10-20

    Recently, the topic of motor competence has figured prominently in the media. The claims made are many, but the research that support the statements is seldom cited. The aim of this review article is to address that deficiency by documenting what is really known about the motor competence of children. Motor competence not only allows children to carry out everyday practical tasks, but it is also an important determinant of their level of self-esteem and of their popularity and status in their peer group. While many studies have shown a significant correlation between motor problems and other problems in the social sphere, it has been difficult to establish causal relationships with any degree of confidence, as there appear to be several interactions which need to be taken into account. Research has shown that 6-10% of Norwegian children in the 7 to 10 year age group have a motor competence well below the norm. It is unusual for motor problems to simply disappear over time. In the absence of intervention the syndrome is likely to continue to manifest itself. More recent research points to some of the circularity in this causal network, children with motor problems having been shown to be less physically active than their peers. In a larger health perspective this in itself can have very serious consequences for the child.

  9. Concurrent TMS to the primary motor cortex augments slow motor learning

    Science.gov (United States)

    Narayana, Shalini; Zhang, Wei; Rogers, William; Strickland, Casey; Franklin, Crystal; Lancaster, Jack L.; Fox, Peter T.

    2013-01-01

    Transcranial magnetic stimulation (TMS) has shown promise as a treatment tool, with one FDA approved use. While TMS alone is able to up- (or down-) regulate a targeted neural system, we argue that TMS applied as an adjuvant is more effective for repetitive physical, behavioral and cognitive therapies, that is, therapies which are designed to alter the network properties of neural systems through Hebbian learning. We tested this hypothesis in the context of a slow motor learning paradigm. Healthy right-handed individuals were assigned to receive 5 Hz TMS (TMS group) or sham TMS (sham group) to the right primary motor cortex (M1) as they performed daily motor practice of a digit sequence task with their non-dominant hand for 4 weeks. Resting cerebral blood flow (CBF) was measured by H215O PET at baseline and after 4 weeks of practice. Sequence performance was measured daily as the number of correct sequences performed, and modeled using a hyperbolic function. Sequence performance increased significantly at 4 weeks relative to baseline in both groups. The TMS group had a significant additional improvement in performance, specifically, in the rate of skill acquisition. In both groups, an improvement in sequence timing and transfer of skills to non-trained motor domains was also found. Compared to the sham group, the TMS group demonstrated increases in resting CBF specifically in regions known to mediate skill learning namely, the M1, cingulate cortex, putamen, hippocampus, and cerebellum. These results indicate that TMS applied concomitantly augments behavioral effects of motor practice, with corresponding neural plasticity in motor sequence learning network. These findings are the first demonstration of the behavioral and neural enhancing effects of TMS on slow motor practice and have direct application in neurorehabilitation where TMS could be applied in conjunction with physical therapy. PMID:23867557

  10. Effects of intraoperative electron irradiation in the dog on cell turnover in intact and surgically-anastomosed aorta and intestine

    International Nuclear Information System (INIS)

    Sindelar, W.F.; Morrow, B.M.; Travis, E.L.; Tepper, J.; Merkel, A.B.; Kranda, K.; Terrill, R.

    1983-01-01

    Adults dogs were subjected to laparotomy and intraoperative electron irradiation after division and reanastomosis of aorta or after construction of a blind loop of small intestine having a transverse suture line and an end-to-side anastomosis. Dogs received intraoperative irradiation of both intact and anastomosed aorta or intestine in doses of 0, 2000, 3000, or 4500 rad. Animals were sacrificed at seven days or three months following treatment. At 24 hours prior to sacrifice, dogs received 5 mCi tritiated thymidine intravenously. Irradiated and non-irradiated segments of aorta and small intestine, including intact and anastomotic regions, were analyzed for tritiated thymidine incorporation and were subjected to autoradiography. Incorporation studies showed diminution in tritiated thymidine uptake by irradiated portions of aorta and small intestine, in both intact and anastomotic regions. Autoradiograms revealed that irradiated areas of intact or anastomotic aorta or intestine had diminished labeling of stromal cells, suggesting a lowered cell proliferative capacity of irradiated tissue compared to non-irradiated portions. Inflammatory cells showed similar labeling indices in irradiated and non-irradiated tissues, both intact and surgically-manipulated, suggesting that irradiation does not significantly affect a subsequent local inflammatory response. Radiation-induced decreases in tritiated thymidine incoporation in irradiated aorta and small intestine were generally more marked at seven days than at three months following irradiation, suggesting that radiation-induced depression of cell turnover rates decreases with time

  11. Individual differences in motor timing and its relation to cognitive and fine motor skills.

    Directory of Open Access Journals (Sweden)

    Håvard Lorås

    Full Text Available The present study investigated the relationship between individual differences in timing movements at the level of milliseconds and performance on selected cognitive and fine motor skills. For this purpose, young adult participants (N = 100 performed a repetitive movement task paced by an auditory metronome at different rates. Psychometric measures included the digit-span and symbol search subtasks from the Wechsler battery as well as the Raven SPM. Fine motor skills were assessed with the Purdue Pegboard test. Motor timing performance was significantly related (mean r = .3 to cognitive measures, and explained both unique and shared variance with information-processing speed of Raven's scores. No significant relations were found between motor timing measures and fine motor skills. These results show that individual differences in cognitive and motor timing performance is to some extent dependent upon shared processing not associated with individual differences in manual dexterity.

  12. Transcriptomics of aged Drosophila motor neurons reveals a matrix metalloproteinase that impairs motor function.

    Science.gov (United States)

    Azpurua, Jorge; Mahoney, Rebekah E; Eaton, Benjamin A

    2018-04-01

    The neuromuscular junction (NMJ) is responsible for transforming nervous system signals into motor behavior and locomotion. In the fruit fly Drosophila melanogaster, an age-dependent decline in motor function occurs, analogous to the decline experienced in mice, humans, and other mammals. The molecular and cellular underpinnings of this decline are still poorly understood. By specifically profiling the transcriptome of Drosophila motor neurons across age using custom microarrays, we found that the expression of the matrix metalloproteinase 1 (dMMP1) gene reproducibly increased in motor neurons in an age-dependent manner. Modulation of physiological aging also altered the rate of dMMP1 expression, validating dMMP1 expression as a bona fide aging biomarker for motor neurons. Temporally controlled overexpression of dMMP1 specifically in motor neurons was sufficient to induce deficits in climbing behavior and cause a decrease in neurotransmitter release at neuromuscular synapses. These deficits were reversible if the dMMP1 expression was shut off again immediately after the onset of motor dysfunction. Additionally, repression of dMMP1 enzymatic activity via overexpression of a tissue inhibitor of metalloproteinases delayed the onset of age-dependent motor dysfunction. MMPs are required for proper tissue architecture during development. Our results support the idea that matrix metalloproteinase 1 is acting as a downstream effector of antagonistic pleiotropy in motor neurons and is necessary for proper development, but deleterious when reactivated at an advanced age. © 2018 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  13. Structural equation modeling of motor impairment, gross motor function, and the functional outcome in children with cerebral palsy.

    Science.gov (United States)

    Park, Eun-Young; Kim, Won-Ho

    2013-05-01

    Physical therapy intervention for children with cerebral palsy (CP) is focused on reducing neurological impairments, improving strength, and preventing the development of secondary impairments in order to improve functional outcomes. However, relationship between motor impairments and functional outcome has not been proved definitely. This study confirmed the construct of motor impairment and performed structural equation modeling (SEM) between motor impairment, gross motor function, and functional outcomes of regarding activities of daily living in children with CP. 98 children (59 boys, 39 girls) with CP participated in this cross-sectional study. Mean age was 11 y 5 mo (SD 1 y 9 mo). The Manual Muscle Test (MMT), the Modified Ashworth Scale (MAS), range of motion (ROM) measurement, and the selective motor control (SMC) scale were used to assess motor impairments. Gross motor function and functional outcomes were measured using the Gross Motor Function Measure (GMFM) and the Functional Skills domain of the Pediatric Evaluation of Disability Inventory (PEDI) respectively. Measurement of motor impairment was consisted of strength, spasticity, ROM, and SMC. The construct of motor impairment was confirmed though an examination of a measurement model. The proposed SEM model showed good fit indices. Motor impairment effected gross motor function (β=-.0869). Gross motor function and motor impairment affected functional outcomes directly (β=0.890) and indirectly (β=-0.773) respectively. We confirmed that the construct of motor impairment consist of strength, spasticity, ROM, and SMC and it was identified through measurement model analysis. Functional outcomes are best predicted by gross motor function and motor impairments have indirect effects on functional outcomes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. The Fate of Dissolved Creosote Compounds in an Intact Fratured Clay Column

    DEFF Research Database (Denmark)

    Broholm, Kim; Arvin, Erik; Hansen, Asger

    1995-01-01

    The fate of 16 different organics typical for creosote was studied under aerobic conditions in a large intact fractured clay column experiment. Some of the organics (benzene, toluene, o-xylene, phenol, and o-cresol) were transported at the same rate as bromide through the fractured clay, whereas ...

  15. Experimental thermodynamics of single molecular motor.

    Science.gov (United States)

    Toyabe, Shoichi; Muneyuki, Eiro

    2013-01-01

    Molecular motor is a nano-sized chemical engine that converts chemical free energy to mechanical motions. Hence, the energetics is as important as kinetics in order to understand its operation principle. We review experiments to evaluate the thermodynamic properties of a rotational F1-ATPase motor (F1-motor) at a single-molecule level. We show that the F1-motor achieves 100% thermo dynamic efficiency at the stalled state. Furthermore, the motor reduces the internal irreversible heat inside the motor to almost zero and achieves a highly-efficient free energy transduction close to 100% during rotations far from quasistatic process. We discuss the mechanism of how the F1-motor achieves such a high efficiency, which highlights the remarkable property of the nano-sized engine F1-motor.

  16. Development of kinesthetic-motor and auditory-motor representations in school-aged children.

    Science.gov (United States)

    Kagerer, Florian A; Clark, Jane E

    2015-07-01

    In two experiments using a center-out task, we investigated kinesthetic-motor and auditory-motor integrations in 5- to 12-year-old children and young adults. In experiment 1, participants moved a pen on a digitizing tablet from a starting position to one of three targets (visuo-motor condition), and then to one of four targets without visual feedback of the movement. In both conditions, we found that with increasing age, the children moved faster and straighter, and became less variable in their feedforward control. Higher control demands for movements toward the contralateral side were reflected in longer movement times and decreased spatial accuracy across all age groups. When feedforward control relies predominantly on kinesthesia, 7- to 10-year-old children were more variable, indicating difficulties in switching between feedforward and feedback control efficiently during that age. An inverse age progression was found for directional endpoint error; larger errors increasing with age likely reflect stronger functional lateralization for the dominant hand. In experiment 2, the same visuo-motor condition was followed by an auditory-motor condition in which participants had to move to acoustic targets (either white band or one-third octave noise). Since in the latter directional cues come exclusively from transcallosally mediated interaural time differences, we hypothesized that auditory-motor representations would show age effects. The results did not show a clear age effect, suggesting that corpus callosum functionality is sufficient in children to allow them to form accurate auditory-motor maps already at a young age.

  17. Human motor unit recordings: origins and insight into the integrated motor system.

    Science.gov (United States)

    Duchateau, Jacques; Enoka, Roger M

    2011-08-29

    Soon after Edward Liddell [1895-1981] and Charles Sherrington [1857-1952] introduced the concept of a motor unit in 1925 and the necessary technology was developed, the recording of single motor unit activity became feasible in humans. It was quickly discovered by Edgar Adrian [1889-1977] and Detlev Bronk [1897-1975] that the force exerted by muscle during voluntary contractions was the result of the concurrent recruitment of motor units and modulation of the rate at which they discharged action potentials. Subsequent studies found that the relation between discharge frequency and motor unit force was characterized by a sigmoidal function. Based on observations on experimental animals, Elwood Henneman [1915-1996] proposed a "size principle" in 1957 and most studies in humans focussed on validating this concept during various types of muscle contractions. By the end of the 20th C, the experimental evidence indicated that the recruitment order of human motor units was determined primarily by motoneuron size and that the occasional changes in recruitment order were not an intended strategy of the central nervous system. Fundamental knowledge on the function of Sherrington's "common final pathway" was expanded with observations on motor unit rotation, minimal and maximal discharge rates, discharge variability, and self-sustained firing. Despite the great amount of work on characterizing motor unit activity during the first century of inquiry, however, many basic questions remain unanswered and these limit the extent to which findings on humans and experimental animals can be integrated and generalized to all movements. 2011 Elsevier B.V. All rights reserved.

  18. Brief Overview of Motor Learning and It's Application to Rehabilitation: Part Ⅰ: Motor Learning Theory

    Institute of Scientific and Technical Information of China (English)

    Christopher A Zaino

    2003-01-01

    @@ 1 DEFINITION OF MOTOR LEARNING Motor learning is the study of how we acquire and modify movements.1 The acquisition of motor skills is the process of learning how to do a particular movement (performance), but the real key to therapeutic intervention is being able to affect permanent changes in motor skills via the process of motor learning. Therefore, motor learning is defined as the ability to retain the ability to perform a motor task at a later time. In rehabilitation, it is important to be cognizant of the concepts of acquisition and retention. We can facilitate acquisition,but do little to assist in the retention of the task (learning). Conversely, we can arrange practice such that acquisition is slowed, but we can actually be assisting learning the task. It is important to have a clear goal in mind and work towards the eventual learning of the task to allow full functional use of that skill.

  19. Tolerance of a standard intact protein formula versus a partially hydrolyzed formula in healthy, term infants

    Directory of Open Access Journals (Sweden)

    Marunycz John D

    2009-06-01

    Full Text Available Abstract Background Parents who perceive common infant behaviors as formula intolerance-related often switch formulas without consulting a health professional. Up to one-half of formula-fed infants experience a formula change during the first six months of life. Methods The objective of this study was to assess discontinuance due to study physician-assessed formula intolerance in healthy, term infants. Infants (335 were randomized to receive either a standard intact cow milk protein formula (INTACT or a partially hydrolyzed cow milk protein formula (PH in a 60 day non-inferiority trial. Discontinuance due to study physician-assessed formula intolerance was the primary outcome. Secondary outcomes included number of infants who discontinued for any reason, including parent-assessed. Results Formula intolerance between groups (INTACT, 12.3% vs. PH, 13.7% was similar for infants who completed the study or discontinued due to study physician-assessed formula intolerance. Overall study discontinuance based on parent- vs. study physician-assessed intolerance for all infants (14.4 vs.11.1% was significantly different (P = 0.001. Conclusion This study demonstrated no difference in infant tolerance of intact vs. partially hydrolyzed cow milk protein formulas for healthy, term infants over a 60-day feeding trial, suggesting nonstandard partially hydrolyzed formulas are not necessary as a first-choice for healthy infants. Parents frequently perceived infant behavior as formula intolerance, paralleling previous reports of unnecessary formula changes. Trial Registration clinicaltrials.gov: NCT00666120

  20. Clonal expansion of genome-intact HIV-1 in functionally polarized Th1 CD4+ T cells.

    Science.gov (United States)

    Lee, Guinevere Q; Orlova-Fink, Nina; Einkauf, Kevin; Chowdhury, Fatema Z; Sun, Xiaoming; Harrington, Sean; Kuo, Hsiao-Hsuan; Hua, Stephane; Chen, Hsiao-Rong; Ouyang, Zhengyu; Reddy, Kavidha; Dong, Krista; Ndung'u, Thumbi; Walker, Bruce D; Rosenberg, Eric S; Yu, Xu G; Lichterfeld, Mathias

    2017-06-30

    HIV-1 causes a chronic, incurable disease due to its persistence in CD4+ T cells that contain replication-competent provirus, but exhibit little or no active viral gene expression and effectively resist combination antiretroviral therapy (cART). These latently infected T cells represent an extremely small proportion of all circulating CD4+ T cells but possess a remarkable long-term stability and typically persist throughout life, for reasons that are not fully understood. Here we performed massive single-genome, near-full-length next-generation sequencing of HIV-1 DNA derived from unfractionated peripheral blood mononuclear cells, ex vivo-isolated CD4+ T cells, and subsets of functionally polarized memory CD4+ T cells. This approach identified multiple sets of independent, near-full-length proviral sequences from cART-treated individuals that were completely identical, consistent with clonal expansion of CD4+ T cells harboring intact HIV-1. Intact, near-full-genome HIV-1 DNA sequences that were derived from such clonally expanded CD4+ T cells constituted 62% of all analyzed genome-intact sequences in memory CD4 T cells, were preferentially observed in Th1-polarized cells, were longitudinally detected over a duration of up to 5 years, and were fully replication- and infection-competent. Together, these data suggest that clonal proliferation of Th1-polarized CD4+ T cells encoding for intact HIV-1 represents a driving force for stabilizing the pool of latently infected CD4+ T cells.