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Sample records for 5-htp-induced head twitch

  1. Effect of the selective 5-HT3 receptor antagonists ICS 205-930 and MDL 72222 on 5-HTP-induced head shaking and behavioral symptoms induced by 5-methoxy-N,N,dimethyltryptamine in rats: comparison with some other 5-HT receptor antagonists.

    PubMed

    Shearman, G T; Tolcsvai, L

    1987-01-01

    The effect of the selective 5-HT3 receptor antagonists ICS 205-930 and MDL 72222 on head shaking behavior induced by L-5-HTP and behavioral symptoms induced with 5-methoxy-N,N,-dimethyltryptamine (5-MeODMT) in rats was evaluated. Both drugs dose-dependently reduced L-5-HTP-induced head shaking but were at least 600 times less potent than pirenperone and ketanserin and at least 50 times less potent than methysergide. ICS 205-930 and MDL 72222 were more than 1000 times less potent than pirenperone or methysergide and 100 times less potent than ketanserin in blocking 5-MeODMT-induced forepaw treading and tremor. Since it appears that head shakes induced by L-5-HTP are mediated by 5-HT2 receptors, these data suggest that ICS 205-930 and MDL 72222 do not significantly interact with 5-HT2 receptors in the brain. Furthermore, the data suggest that ICS 205-930 and MDL 72222 lack appreciable antagonistic activity at the 5-HT receptor(s) mediating those behavioral effects induced by 5-MeODMT. PMID:3114804

  2. Comparative study of the effects of stimulation or blockade of beta-adrenoceptors on the head-twitches induced in mice by 5-hydroxytryptophan versus 5-methoxy-N, N-dimethyltryptamine.

    PubMed

    Martin, P; Soubrié, P; Simon, P

    1986-01-01

    This study aimed at comparing the effects of blockade or stimulation of beta-adrenoceptors on the head-twitch response induced in mice by direct (5-MeODMT) or indirect (5-HTP) activation of serotonergic receptors shows that: beta-agonists (clenbuterol and salbutamol) increased the 5-HTP-induced head-twitches and decreased the response to 5-MeODMT. beta-agonists (propranolol and penbutolol) reduced the head-twitches elicited by 5-HTP but enhanced those induced by 5-MeODMT. Under our experimental conditions, desipramine behaved like the beta-agonists studied. Prior intracerebroventricular injection of 5,7-DHT enhanced the response to 5-MeODMT but did not prevent the antagonism of clenbuterol against 5-MeODMT-induced head-twitches. These findings suggest that beta-receptors are in a position to regulate differentially serotonin transmission. PMID:2875219

  3. Role of endocannabinoid and glutamatergic systems in DOI-induced head-twitch response in mice.

    PubMed

    Egashira, Nobuaki; Shirakawa, Atsunori; Okuno, Ryoko; Mishima, Kenichi; Iwasaki, Katsunori; Oishi, Ryozo; Fujiwara, Michihiro

    2011-07-01

    We previously reported that systemic administration of the endocannabinoid anandamide inhibited the head-twitches induced by the hallucinogenic drug 2,5-dimethoxy-4-iodoamphetamine (DOI) in mice, which is mediated via the activation of 5-HT(2A) receptors. Endocannabinoid and glutamatergic systems have been suggested to modulate the function of 5-HT(2A) receptors. In the present study, we further investigated the role of endocannabinoid and glutamatergic systems in DOI-induced head-twitch response in mice. An anandamide transport inhibitor AM404 (0.3-3mg/kg, i.p.), a fatty acid amide hydrolase inhibitor URB597 (0.1-10mg/kg, i.p.), a glutamate release inhibitor riluzole (0.3 and 1mg/kg, i.p.), a natural glutamate analog l-glutamylethylamide (theanine, 1 and 3mg/kg, p.o.) and an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor antagonist NBQX (0.01-0.3mg/kg, i.p.) significantly inhibited DOI-induced head-twitch response. The AMPA receptor positive modulator aniracetam (30 or 100mg/kg, p.o.) reversed inhibition of head-twitch response by NBQX and URB597. These findings indicated that endocannabinoid and glutamatergic systems participate in the mechanism of action of DOI to induce head-twitch response. PMID:21504759

  4. Conditioned lick behavior and evoked responses using whisker twitches in head restrained rats.

    PubMed

    Topchiy, Irina A; Wood, Rachael M; Peterson, Breeanne; Navas, Jinna A; Rojas, Manuel J; Rector, David M

    2009-01-30

    To examine whisker barrel evoked response potentials in chronically implanted rats during behavioral learning with very fast response times, rats must be calm while immobilized with their head restrained. We quantified their behaviors during training with an ethogram and measured each individual animals' progress over the training period. Once calm under restraint, rats were conditioned to differentiate between a reward and control whisker twitch, then provide a lick response when presented with the correct stimulus, rewarded by a drop of water. Rats produced the correct licking response (after reward whisker twitch), and learned not to lick after a control whisker was twitched. By implementing a high-density 64-channel electrocorticogram (ECoG) electrode array, we mapped the barrel field of the somatosensory cortex with high spatial and temporal resolution during conditioned lick behaviors. In agreement with previous reports, we observe a larger evoked response after training, probably related to mechanisms of cortical plasticity. PMID:18718491

  5. Nicotine attenuates DOI-induced head-twitch response in mice: implications for Tourette syndrome.

    PubMed

    Tizabi, Y; Russell, L T; Johnson, M; Darmani, N A

    2001-10-01

    Tourette syndrome (TS), a chronic neuropsychiatric disorder, is characterized by motor and vocal tics. Preliminary clinical studies indicate possible therapeutic benefits of nicotine in the treatment of Tourette's syndrome (TS). It has been proposed that twitches of the head in mice or twitches of head and shoulders in rats following administration of the selective 5HT(2A/C) agonist DOI (1-)2,5-dimethoxy-4-iodophenyl-2-aminopropane, can serve as an animal model of tics in TS. In this study, the effects of acute and chronic administration of nicotine on DOI-induced head twitch response (HTR) in male albino ICR mice were evaluated. Both acute and chronic nicotine (daily injections for 10 days) reduced the DOI-induced HTR. Moreover, chronic administration of DOI (1 mg/kg/day for 10 days) resulted in 65% increase in [125I]alpha-bungarotoxin binding in cerebellum and 41% increase in striatal [3H]cytisine binding. However, the acute inhibitory effects of nicotine were not blocked by pretreatment with the nicotinic antagonist, mecamylamine. Indeed, at higher doses, mecamylamine also reduced the DOI-induced HTR. The data suggest that both nicotine and mecamylamine may be of therapeutic potential in the treatment of some symptoms of TS. PMID:11513358

  6. Synergistic effect of decreased opioid activity and sleep deprivation on head-twitch response in mice.

    PubMed

    Ionov, Ilya D

    2010-07-01

    In schizophrenia, an opioidergic understimulation and a decreased sleep duration are found. The pathogenic significance of these factors is unknown. The present study assessed the influence of the combination of the factors on serotonergic 2A (5-HT(2A)) receptors that are possibly related to psychosis development. 2,5-dimethoxy-4-iodoamphetamine (DOI)-induced head-twitch response in mice was used as a model of 5-HT(2A) receptor functioning. Mice underwent sleep deprivation and/or a blockade of opioidergic receptors with naloxone. To evaluate the involvement of 5-HT(2A) receptor in effects observed, animals were pretreated with MDL 100,907, a potent and selective antagonist of 5-HT(2A) receptor. As was found, 4h of sleep deprivation followed by administration of naloxone significantly increases the frequency of head twitches, with sleep deprivation and naloxone being ineffective alone. The action of the "sleep deprivation-opioid understimulation" combination is antagonized completely by MDL 100,907. Thus, some schizophrenia-associated factors can synergistically enhance the activity of 5-HT(2A) receptors. These results suggest the above factors being pathogenically relevant in schizophrenia. PMID:20399224

  7. Suppressive effect of mitragynine on the 5-methoxy-N,N-dimethyltryptamine-induced head-twitch response in mice.

    PubMed

    Matsumoto, K; Mizowaki, M; Takayama, H; Sakai, S; Aimi, N; Watanabe, H

    1997-01-01

    We investigated the effects of mitragynine, a major alkaloid isolated from the leaves of Mitragyna speciosa Korth (Rubiaceae), on the 5-HT2A receptor-mediated head-twitch response in mice. Intraperitoneal injection of mitragynine (5-30 mg/kg), as well as intraperitoneal injection of 5-HT2A receptor antagonist ritanserin, inhibited the 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT: 16 mg/kg, IP)-induced head-twitch response in a dose-dependent manner. In contrast, mitragynine affected neither head-weaving caused by 5-MeO-DMT, nor drug-free spontaneous motor activity. Pretreatment of mice with reserpine (5 mg/kg, IP), p-chlorophenylalanine (p-CPA, 300 mg/kg x 3 times, IP), or 6-hydroxydopamine (6-OHDA, 50 micrograms/mouse, ICV) plus nomifensine (5 mg/kg, IP) did not change the suppressant effect of mitragynine on the head-twitch response caused by 5-MeO-DMT. On the other hand, the alpha 2-adrenoceptor antagonists yohimbine (0.5 mg/kg, IP), and idazoxan (0.2 mg/kg, IP), significantly attenuated the suppressant effect of mitragynine. Lesion of central noradrenergic systems by 6-OHDA plus nomifensine did not alter the effect of idazoxan (0.2 mg/kg) on mitragynine-induced suppression of the head-twitch response. These results indicate that stimulation of postsynaptic alpha 2-adrenoceptor, blockade of 5-HT2A receptors, or both, are involved in suppression of 5-HT2A receptor-mediated head-twitch response by mitragynine. PMID:9164589

  8. Enhanced head-twitch response to 5-HT-related agonists in thiamine-deficient mice.

    PubMed

    Nakagawasai, O; Murata, A; Arai, Y; Ohba, A; Wakui, K; Mitazaki, S; Niijima, F; Tan-No, K; Tadano, T

    2007-01-01

    While many studies suggest an involvement of brain serotonergic systems in neuro-psychiatric disorders such as schizophrenia and depression, their role in Wernicke-Korsakoff syndrome (WKS) remains unclear. Since dietary thiamine deficiency (TD) in mice is considered as a putative model of WKS, it was used in the present study to investigate the function of serotonergic neurons in this disorder. After 20 days of TD feeding, the intensity of tryptophan hydroxylase immunofluorescence was found to be significantly decreased in the dorsal and medial raphe nuclei. In addition, the head-twitch response (HTR) elicited by the intracerebroventricular administration of the 5-HT(2A) agonist 2,5-dimethoxy-4-iodoamphetamine hydrochloride (DOI) was significantly increased in TD versus control mice, whereas the injection of ketanserin, a 5-HT(2A) receptor antagonist, prevented this enhancement. A single injection of thiamine HCl on the 19th day of TD feeding did not reduce the enhanced DOI-induced HTR. On the other hand, the administration of d-fenfluramine, a 5-HT releaser, did not enhance the HTR in TD mice. Together, our results indicate that TD causes a super-sensitivity of 5-HT(2A) receptors by reducing presynaptic 5-HT synthesis derived from degenerating neurons projecting from the raphe nucleus. PMID:17372673

  9. Eyelid twitch

    MedlinePlus

    ... meantime, the following steps may help: Get more sleep. Drink less caffeine. Lubricate your eyes with eye drops. If twitching is severe or lasts a long time, small injections of botulinum toxin can control the spasms.

  10. Muscle twitching

    MedlinePlus

    ... or other stimulants) Lack of sleep Drug side effect (such as from diuretics, corticosteroids, or estrogens) Exercise (twitching is seen after exercise) Lack of nutrients in the diet (deficiency) Stress Medical conditions that cause metabolic disorders, including low ...

  11. Tolerance and Cross-Tolerance to Head Twitch Behavior Elicited by Phenethylamine- and Tryptamine-Derived Hallucinogens in Mice

    PubMed Central

    Smith, Douglas A.; Bailey, Jessica M.; Williams, Diarria

    2014-01-01

    The serotonin 5-hydroxytryptamine 2A (5-HT2A) receptor is a potential therapeutic target to a host of neuropsychiatric conditions, but agonist actions at this site are linked to abuse-related hallucinogenic effects that may limit therapeutic efficacy of chronic drug administration. Tolerance to some effects of hallucinogens has been observed in humans and laboratory animals, but the understanding of tolerance and cross-tolerance between distinct structural classes of hallucinogens is limited. Here, we used the drug-elicited head twitch response (HTR) in mice to assess the development of tolerance and cross-tolerance with two phenethylamine-derived [DOI (2,5-dimethoxy-4-iodoamphetamine) and 2C-T-7 (2,5-dimethoxy-4-propylthiophenethylamine)] and two tryptamine-derived [DPT (N,N-dipropyltryptamine) and DIPT (N,N-diisopropyltryptamine)] drugs with agonist affinity for 5-HT2A receptors. Tolerance developed to HTR elicited by daily DOI or 2C-T-7, but not to HTR elicited by DPT or DIPT. DOI-elicited tolerance was not surmountable with dose, and a similar insurmountable cross-tolerance was evident when DOI-tolerant mice were tested with various doses of 2C-T-7 or DPT. These studies suggest that the use of phenethylamine-derived hallucinogens as therapeutic agents may be limited not only by their abuse potential, but also by the rapid development of tolerance that would likely be maintained even if a patient were switched to a different 5-HT2A agonist medication from a distinct structural class. However, these experiments also imply that tryptamine-derived hallucinogens might have a reduced potential for tolerance development, compared with phenethylamine-derived 5-HT2A agonists, and might therefore be more suitable for chronic administration in a therapeutic context. PMID:25271256

  12. The effect of the sigma-1 receptor selective compound LS-1-137 on the DOI-induced head twitch response in mice.

    PubMed

    Malik, Maninder; Rangel-Barajas, Claudia; Mach, Robert H; Luedtke, Robert R

    2016-09-01

    Several receptor mediated pathways have been shown to modulate the murine head twitch response (HTR). However, the role of sigma receptors in the murine (±)-2,5-dimethoxy-4-iodoamphetamine (DOI)-induced HTR has not been previously investigated. We examined the ability of LS-1-137, a novel sigma-1 vs. sigma-2 receptor selective phenylacetamide, to modulate the DOI-induced HTR in DBA/2J mice. We also assessed the in vivo efficacy of reference sigma-1 receptor antagonists and agonists PRE-084 and PPCC. The effect of the sigma-2 receptor selective antagonist RHM-1-86 was also examined. Rotarod analysis was performed to monitor motor coordination after LS-1-137 administration. Radioligand binding techniques were used to determine the affinity of LS-1-137 at 5-HT2A and 5-HT2C receptors. LS-1-137 and the sigma-1 receptor antagonists haloperidol and BD 1047 were able to attenuate a DOI-induced HTR, indicating that LS-1-137 was acting in vivo as a sigma-1 receptor antagonist. LS-1-137 did not compromise rotarod performance within a dose range capable of attenuating the effects of DOI. Radioligand binding studies indicate that LS-1-137 exhibits low affinity binding at both 5-HT2A and 5-HT2C receptors. Based upon the results from these and our previous studies, LS-1-137 is a neuroprotective agent that attenuates the murine DOI-induced HTR independent of activity at 5-HT2 receptor subtypes, D2-like dopamine receptors, sigma-2 receptors and NMDA receptors. LS-1-137 appears to act as a sigma-1 receptor antagonist to inhibit the DOI-induced HTR. Therefore, the DOI-induced HTR can be used to assess the in vivo efficacy of sigma-1 receptor selective compounds. PMID:27397487

  13. Head-twitch response in rodents induced by the hallucinogen 2,5-dimethoxy-4-iodoamphetamine: a comprehensive history, a re-evaluation of mechanisms, and its utility as a model

    PubMed Central

    Canal, Clint E.; Morgan, Drake

    2013-01-01

    Two primary animal models persist for assessing hallucinogenic potential of novel compounds and for examining the pharmacological and neurobiological substrates underlying the actions of classical hallucinogens, the two-lever drug discrimination procedure and the drug-induced head-twitch response (HTR) in rodents. The substituted amphetamine hallucinogen, serotonin 2 (5-HT2) receptor agonist, 2,5-dimethoxy-4-iodoamphetamine (DOI) has emerged as the most popular pharmacological tool used in HTR studies of hallucinogens. Synthesizing classic, recent, and relatively overlooked findings, addressing ostensibly conflicting observations, and considering contemporary theories in receptor and behavioural pharmacology, this review provides an up-to-date and comprehensive synopsis of DOI and the HTR model, from neural mechanisms to utility for understanding psychiatric diseases. Also presented is support for the argument that, although both the two-lever drug discrimination and the HTR models in rodents are useful for uncovering receptors, interacting proteins, intracellular signalling pathways, and neurochemical processes affected by DOI and related classical hallucinogens, results from both models suggest they are not reporting hallucinogenic experiences in animals. PMID:22517680

  14. Babies' Sleep 'Twitching' May Aid Their Development

    MedlinePlus

    ... 160211.html Babies' Sleep 'Twitching' May Aid Their Development Tiny movements help trigger muscle activity, researchers say ... actually be part of a baby's motor skills development. When a baby's body twitches during rapid eye ...

  15. Effects of 071031B, a novel serotonin and norepinephrine reuptake inhibitor, on monoamine system in mice and rats.

    PubMed

    Xue, Rui; He, Xin-Hua; Yuan, Li; Chen, Hong-Xia; Zhang, Li-Ming; Yong, Zheng; Yu, Gang; Fan, Shi-Yong; Li, Yun-Feng; Zhong, Bo-Hua; Zhang, You-Zhi

    2016-01-01

    Our previous study indicated that 071031B, a novel potential serotonin and norepinephrine reuptake inhibitor, showed robust antidepressant activity in multiple depression models, and could simultaneously inhibit 5-HT and NE reuptake in vitro. The present study was to evaluate the effects of 071031B on monoamine system in vivo, by using pharmacological models, including 5-HTP induced head-twitch test, yohimbine toxicity potentiation test, and reserpine induced hypothermia test, and determining monoamine transmitter levels in reserpine induced monoamine depletion model or chronic unpredictable stress (CUS) model. Results in pharmacological models indicated that acute administration of 071031B at 5-20 mg/kg significantly enhanced 5-HTP induced head-twitch behavior, potentiated yohimbine induced lethal rate, and reversed reserpine induced hypothermia. Further monoamine assays demonstrated that acute or chronic administration of 071031B at 10 or 20 mg/kg increased 5-HT and/or NE levels in various brain regions in reserpine or CUS induced monoamine depletion models, respectively, without effect on DA and its metabolites. Our results revealed that 071031B produces potent inhibition of 5-HT and NE reuptake in vivo. PMID:26318675

  16. Cinnamomum cassia: an implication of serotonin reuptake inhibition in animal models of depression.

    PubMed

    Zada, Wahid; Zeeshan, Sara; Bhatti, Huma Aslam; Mahmood, Wajahat; Rauf, Khalid; Abbas, Ghulam

    2016-05-01

    The aim of the study was to explore the traditional use of Cinnamomum cassia against depression. The standardised methanolic extract of the bark of C. cassia was evaluated for antidepressant activity using various behavioural tests, i.e. tail suspension test (TST), forced swim test (FST) and locomotor activity test. The serotonergic and noradrenergic modulation was assessed using 5-hydroxytryptophan (5-HTP)-induced head twitches and yohimbine potentiation tests, respectively. The fluoxetine and phenelzine were used as positive controls in the study. The C. cassia extract significantly decreased the immobility time in TST (maximum effective dose tested was 50 mg/kg) while no effect was observed in FST and locomotor activity test. The extract significantly increased the 5-HTP-induced head twitches while yohimbine-induced lethality remained unaltered. The aforementioned results are similar to that caused by fluoxetine. The standardised methanolic extract of C. cassia demonstrated antidepressant activity that can be attributed to rise in serotonin levels. PMID:26134381

  17. Twitching in Sensorimotor Development from Sleeping Rats to Robots

    PubMed Central

    Marques, Hugo Gravato; Iida, Fumiya

    2013-01-01

    It is still not known how the “rudimentary” movements of fetuses and infants are transformed into the coordinated, flexible, and adaptive movements of adults. In addressing this important issue, we consider a behavior that has been perennially viewed as a functionless by-product of a dreaming brain: the jerky limb movements called myoclonic twitches. Recent work has identified the neural mechanisms that produce twitching as well as those that convey sensory feedback from twitching limbs to the spinal cord and brain. In turn, these mechanistic insights have helped inspire new ideas about the functional roles that twitching might play in the self-organization of spinal and supraspinal sensorimotor circuits. Striking support for these ideas is coming from the field of developmental robotics: When twitches are mimicked in robot models of the musculoskeletal system, basic neural circuitry self-organizes. Mutually inspired biological and synthetic approaches promise not only to produce better robots, but also to solve fundamental problems concerning the developmental origins of sensorimotor maps in the spinal cord and brain. PMID:23787051

  18. Development of twitching in sleeping infant mice depends on sensory experience.

    PubMed

    Blumberg, Mark S; Coleman, Cassandra M; Sokoloff, Greta; Weiner, Joshua A; Fritzsch, Bernd; Fritszch, Bernd; McMurray, Bob

    2015-03-01

    Myoclonic twitches are jerky movements that occur exclusively and abundantly during active (or REM) sleep in mammals, especially in early development [1-4]. In rat pups, limb twitches exhibit a complex spatiotemporal structure that changes across early development [5]. However, it is not known whether this developmental change is influenced by sensory experience, which is a prerequisite to the notion that sensory feedback from twitches not only activates sensorimotor circuits but modifies them [4]. Here, we investigated the contributions of proprioception to twitching in newborn ErbB2 conditional knockout mice that lack muscle spindles and grow up to exhibit dysfunctional proprioception [6-8]. High-speed videography of forelimb twitches unexpectedly revealed a category of reflex-like twitching-comprising an agonist twitch followed immediately by an antagonist twitch-that developed postnatally in wild-types/heterozygotes, but not in knockouts. Contrary to evidence from adults that spinal reflexes are inhibited during twitching [9-11], this finding suggests that twitches trigger the monosynaptic stretch reflex and, by doing so, contribute to its activity-dependent development [12-14]. Next, we assessed developmental changes in the frequency and organization (i.e., entropy) of more-complex, multi-joint patterns of twitching; again, wild-types/heterozygotes exhibited developmental changes in twitch patterning that were not seen in knockouts. Thus, targeted deletion of a peripheral sensor alters the normal development of local and global features of twitching, demonstrating that twitching is shaped by sensory experience. These results also highlight the potential use of twitching as a uniquely informative diagnostic tool for assessing the functional status of spinal and supraspinal circuits. PMID:25702578

  19. Quantifying Spatiotemporal Patterns in the Expansion of Twitching Bacterial Colonies

    NASA Astrophysics Data System (ADS)

    Shelton, Erin; Giuliani, Maximiliano; Burrows, Lori; Dutcher, John

    2015-03-01

    Type IV pili (T4P) are very thin (5-8 nm in diameter) protein filaments that can be extended and retracted by certain classes of Gram-negative bacteria including P. aeruginosa. These bacteria use T4P to move across viscous interfaces, referred to twitching motility. Twitching can occur for isolated cells or in a collective manner. We have developed experimental and data analysis techniques to quantify the expansion of P. aeruginosa PAO1 bacterial colonies at the glass-agar interface under well-controlled environmental conditions. By using particle image velocimetry (PIV) and Fourier analysis techniques, we have characterized the evolution of the advancing front of expanding colonies for a range of agar concentrations. This has allowed us to observe a transition in the collective motion of the bacterial cells as the agar concentration is increased.

  20. Parameters of human motor unit twitches obtained by intramuscular microstimulation.

    PubMed

    Elek, J M; Kossev, A; Dengler, R; Schubert, M; Wohlfahrt, K; Wolf, W

    1992-01-01

    Intramuscular microstimulation of motor axons was used to study twitch responses of 209 motor units (MUs) in the first dorsal interosseus muscle (FDI) of 20 normal subjects. Twitch peak force (TF), maximum rate of rise of force (MRRF), contraction time (CT) and one-half relaxation time (HRT) were determined. The distributions of TF (mean 16.0 mN, median 10.3 mN) and MRRF (mean 0.88 N s-1, median 0.66 N s-1) were skewed to the right with the majority of the values lying in the lower ranges, whereas CT (mean 63 ms, median 62 ms) and HRT (mean 61 ms, median 58 ms) were approximately normally distributed. TF was significantly correlated with MRRF, but not with CT in contrast with studies of cat gastrocnemius muscle. TF values were similar to those obtained by spike-triggered averaging in the same muscle. The method proved to be reliable and appropriate for use in patients. Examples of MU twitch parameters from three patients with chronic partial denervation of the FDI are described. PMID:1483052

  1. Six1 and Eya1 expression can reprogram adult muscle from the slow-twitch phenotype into the fast-twitch phenotype.

    PubMed

    Grifone, Raphaelle; Laclef, Christine; Spitz, François; Lopez, Soledad; Demignon, Josiane; Guidotti, Jacques-Emmanuel; Kawakami, Kiyoshi; Xu, Pin-Xian; Kelly, Robert; Petrof, Basil J; Daegelen, Dominique; Concordet, Jean-Paul; Maire, Pascal

    2004-07-01

    Muscle fibers show great differences in their contractile and metabolic properties. This diversity enables skeletal muscles to fulfill and adapt to different tasks. In this report, we show that the Six/Eya pathway is implicated in the establishment and maintenance of the fast-twitch skeletal muscle phenotype. We demonstrate that the MEF3/Six DNA binding element present in the aldolase A pM promoter mediates the high level of activation of this promoter in fast-twitch glycolytic (but not in slow-twitch) muscle fibers. We also show that among the Six and Eya gene products expressed in mouse skeletal muscle, Six1 and Eya1 proteins accumulate preferentially in the nuclei of fast-twitch muscles. The forced expression of Six1 and Eya1 together in the slow-twitch soleus muscle induced a fiber-type transition characterized by the replacement of myosin heavy chain I and IIA isoforms by the faster IIB and/or IIX isoforms, the activation of fast-twitch fiber-specific genes, and a switch toward glycolytic metabolism. Collectively, these data identify Six1 and Eya1 as the first transcriptional complex that is able to reprogram adult slow-twitch oxidative fibers toward a fast-twitch glycolytic phenotype. PMID:15226428

  2. A Temporally Controlled Inhibitory Drive Coordinates Twitch Movements during REM Sleep.

    PubMed

    Brooks, Patricia L; Peever, John

    2016-05-01

    During REM sleep, skeletal muscles are paralyzed in one moment but twitch and jerk in the next. REM sleep twitches are traditionally considered random motor events that result from momentary lapses in REM sleep paralysis [1-3]. However, recent evidence indicates that twitches are not byproducts of REM sleep, but are in fact self-generated events that could function to promote motor learning and development [4-6]. If REM twitches are indeed purposefully generated, then they should be controlled by a coordinated and definable mechanism. Here, we used behavioral, electrophysiological, pharmacological, and neuroanatomical methods to demonstrate that an inhibitory drive onto skeletal motoneurons produces a temporally coordinated pattern of muscle twitches during REM sleep. First, we show that muscle twitches in adult rats are not uniformly distributed during REM sleep, but instead follow a well-defined temporal trajectory. They are largely absent during REM initiation but increase steadily thereafter, peaking toward REM termination. Next, we identify the transmitter mechanism that controls the temporal nature of twitch activity. Specifically, we show that a GABA and glycine drive onto motoneurons prevents twitch activity during REM initiation, but progressive weakening of this drive functions to promote twitch activity during REM termination. These results demonstrate that REM twitches are not random byproducts of REM sleep, but are instead rather coherently generated events controlled by a temporally variable inhibitory drive. PMID:27040781

  3. Dexmedetomidine controls twitch-convulsive syndrome in the course of uremic encephalopathy.

    PubMed

    Nomoto, Koichi; Scurlock, Corey; Bronster, David

    2011-12-01

    An 85 year old man with a history of chronic renal insufficiency was admitted to the cardiothoracic intensive care unit after aortic valve replacement. His postoperative course was marked by acute oliguric renal failure for high blood urea nitrogen (BUN) and acute hyperactive delirium. At this time he also developed tremors with muscle twitching; he received no other form of sedatives. A neurology consult made the diagnosis of twitch-convulsive syndrome associated with uremic encephalopathy. While the patient was receiving the dexmedetomidine infusion, the signs of the twitch-convulsive syndrome, particularly the twitching and tremors, disappeared. Within 30 minutes of the end of the dexmedetomidine infusion, symptoms of the twitch-convulsive syndrome returned, manifesting as acute tremulousness. After several dialysis treatments, his BUN decreased and the dexmedetomidine was weaned, without return of the symptoms of twitch-convulsive syndrome. PMID:22137518

  4. Using laser tweezers to measure twitching motility in Neisseria.

    PubMed

    Maier, Berenike

    2005-06-01

    Dynamic properties of type IV pili are essential for their function in bacterial infection, twitching motility and gene transfer. Laser tweezers are versatile tools to study the molecular mechanism underlying pilus dynamics at the single molecule level. Recently, these optical tweezers have been used to monitor pilus elongation and retraction in vivo at a resolution of several nanometers. The force generated by type IV pili exceeds 100 pN making pili the strongest linear motors characterized to date. The study of pilus dynamics at the single molecule level sheds light on kinetics, force generation, switching and mechanics of the Neisseria gonorrhoeae pilus motor. PMID:15939360

  5. Classification of involuntary movements in dogs: Tremors and twitches.

    PubMed

    Lowrie, Mark; Garosi, Laurent

    2016-08-01

    This review focuses on important new findings in the field of involuntary movements (IM) in dogs and illustrates the importance of developing a clear classification tool for diagnosing tremor and twitches. Developments over the last decade have changed our understanding of IM and highlight several caveats in the current tremor classification. Given the ambiguous association between tremor phenomenology and tremor aetiology, a more cautious definition of tremors based on clinical assessment is required. An algorithm for the characterisation of tremors is presented herein. The classification of tremors is based on the distinction between tremors that occur at rest and tremors that are action-related; tremors associated with action are divided into postural or kinetic. Controversial issues are outlined and thus reflect the open questions that are yet to be answered from an evidence base of peer-reviewed published literature. Peripheral nerve hyper-excitability (PNH; cramps and twitches) may manifest as fasciculations, myokymia, neuromyotonia, cramps, tetany and tetanus. It is anticipated that as we learn more about the aetiology and pathogenesis of IMs, future revisions to the classification will be needed. It is therefore the intent of this work to stimulate discussions and thus contribute to the development of IM research. PMID:27387736

  6. Excessive twitch movements in rapid eye movement sleep with daytime sleepiness.

    PubMed

    Mizuma, H; Sakamoto, T

    1997-12-01

    A man who showed excessive twitch movement, such as fragmentary myoclonus (FM) and periodic movements in sleep (PMS) predominantly during REM sleep, is reported. He complained of excessive daytime sleepiness (EDS). After examination, his twitch movements were shown not to accompany narcolepsy, and his EDS were considered to originate from nocturnal sleep disturbance caused by FM and PMS. PMID:9472125

  7. Single-cell twitching chemotaxis in developing biofilms.

    PubMed

    Oliveira, Nuno M; Foster, Kevin R; Durham, William M

    2016-06-01

    Bacteria form surface-attached communities, known as biofilms, which are central to bacterial biology and how they affect us. Although surface-attached bacteria often experience strong chemical gradients, it remains unclear whether single cells can effectively perform chemotaxis on surfaces. Here we use microfluidic chemical gradients and massively parallel automated tracking to study the behavior of the pathogen Pseudomonas aeruginosa during early biofilm development. We show that individual cells can efficiently move toward chemoattractants using pili-based "twitching" motility and the Chp chemosensory system. Moreover, we discovered the behavioral mechanism underlying this surface chemotaxis: Cells reverse direction more frequently when moving away from chemoattractant sources. These corrective maneuvers are triggered rapidly, typically before a wayward cell has ventured a fraction of a micron. Our work shows that single bacteria can direct their motion with submicron precision and reveals the hidden potential for chemotaxis within bacterial biofilms. PMID:27222583

  8. Mesopontine contribution to the expression of active 'twitch' sleep in decerebrate week-old rats.

    PubMed

    Kreider, J C; Blumberg, M S

    2000-07-28

    Myoclonic twitching is a ubiquitous feature of infant behavior that has been used as an index of active sleep. Although the active sleep of infants differs in some ways from the REM sleep of adults, their marked similarities have led many to view them them as homologous behavioral states. Recently, however, this view has been challenged. One avenue for resolving this issue entails examination of the neural substrates of active sleep. If the neural substrates of active sleep were found to be similar to those of REM sleep, then this would support the view that the two states are homologous. Therefore, in the present study, decerebrations were performed in the pons and midbrain to determine whether the mesopontine region is important for the expression of active sleep in infants, just as it is for the expression of REM sleep in adults. It was found that, in comparison to controls, caudal pontine decerebrations reduced myoclonic twitching by 76%, rostral pontine decerebrations reduced twitching by 40%, and midbrain transections had no significant effect on twitching. Moreover, analysis of the temporal organization of twitching indicated that pontine decerebrations predominantly affected high-frequency twitching while leaving unaffected the low-frequency twitching that is thought to be contributed by local spinal circuits at this age. These results indicate that the mesopontine region plays a central role in the expression of active sleep in infant rats. PMID:10924687

  9. Rapid eye movements, muscle twitches and sawtooth waves in the sleep of narcoleptic patients and controls.

    PubMed

    Geisler, P; Meier-Ewert, K; Matsubayshi, K

    1987-12-01

    Seventeen unmedicated patients with narcolepsy-cataplexy and 17 age- and sex-matched controls were recorded polygraphically for 3 consecutive nights. Rapid eye movements (REMs), m. mentalis twitches and sawtooth waves in the EEG were visually scored. REM and twitch densities during REM sleep were significantly higher in the patients than in the controls. The distribution pattern of REMs and twitches was altered in the patients: twitch density peaked in the first REM period and density of REMs showed an even distribution across all the REM periods of the night. In the controls both REM and twitch density increased from the first to the second REM period. We therefore assume that in the narcoleptics phasic activity of REM sleep is disinhibited. Densities of REMs, twitches and sawtooth waves did not correlate with one another in patients and controls. They appear to be independently regulated. The REM periods of the patients contained 3 times as many waking epochs as those of the controls. This suggests that in narcolepsy the transition REM/waking is selectively facilitated. The REM/NREM ratio of twitch and sawtooth wave densities was the same in patients and controls. PMID:2445541

  10. Nicotine-Induced Modulation of the Cholinergic Twitch Response in the Ileum of Guinea Pig.

    PubMed

    Donnerer, Josef; Liebmann, Ingrid

    2015-01-01

    In the present study, the direct drug effects of nicotine and its effects on the cholinergic twitch responses of the electrically stimulated longitudinal muscle-myenteric plexus strip from the ileum of guinea pig were investigated. Nicotine dose-dependently (0.3-10 µmol/l) evoked the well-known contractile responses on its own. Whereas the interposed twitch responses remained present without a change in height at 1 µmol/l nicotine, a nicotine concentration of 3 µmol/l slightly and a concentration of 10 µmol/l markedly diminished the twitch during their presence. After the washout of 1-10 µmol/l nicotine, the height of the twitch response was also temporarily and significantly reduced by 30-77%. The P2X purinoceptor agonist αβ-methylene ATP (1-10 µmol/l) dose-dependently induced contractions on its own and reduced the twitch response during its presence in the organ bath; however, it did not diminish the twitch responses after washout of the drug as nicotine did. The P2X antagonist pyridoxalphosphate-6-azophenyl-2'-4'-disulphonic acid, the NMDA channel blocker MK-801 and the inhibitor of small conductance Ca(2+)-activated K(+) (SK) channels apamin reduced the contractile effect of 1 µmol/l nicotine. Apamin also significantly prevented the 'post-nicotine inhibition of the twitch' following the washout of 1-3 µmol/l nicotine. As a conclusion, we provide evidence for a functional interaction between nicotinic receptors and the P2X receptors in the ileum of the guinea pig. The 'post-nicotine inhibition of the twitch' is not due to nicotinic acetylcholine receptor desensitization or transmitter depletion, but most probably the secondary effects of nicotine on SK channels determine the reduced cholinergic motor neuron excitability. PMID:26088942

  11. Coexistence of twitch potentiation and tetanic force decline in rat hindlimb muscle

    NASA Technical Reports Server (NTRS)

    Rankin, Lucinda L.; Enoka, Roger M.; Volz, Kathryn A.; Stuart, Douglas G.

    1988-01-01

    The effect of whole-muscle fatigue on the isometric twitch was investigated in various hindlimb muscles of anesthetized rats, using an experimental protocol designed to assess the levels of fatigability in motor units. The results of EMG and force measurements revealed the existence of a linear relationship between fatigability and the magnitude of the twitch force following the fatigue test in both soleus and extensor digitorum longus muscles.

  12. Concomitant changes in afterhyperpolarization and twitch following repetitive stimulation of fast motoneurones and motor units.

    PubMed

    Krutki, P; Mrówczyński, W; Raikova, R; Celichowski, J

    2014-02-01

    The study aimed at determining changes in a course of motoneuronal afterhyperpolarization (AHP) and in contractile twitches of motor units (MUs) during activity evoked by increasing number of stimuli (from 1 to 5), at short interspike intervals (5 ms). The stimulation was applied antidromically to spinal motoneurones or to isolated axons of MUs of the medial gastrocnemius muscle within two separate series of experiments on anesthetized rats. Alterations in the amplitude and time parameters of the AHP of successive spikes were compared to changes in force and time course of successive twitches obtained by mathematical subtraction of tetanic contractions evoked by one to five stimuli. The extent of changes of the studied parameters depended on a number of applied stimuli. The maximal modulation of the AHP and twitch parameters (a prolongation and an increase in the AHP and twitch amplitudes) was typically observed after the second pulse, while higher number of pulses at the same frequency did not induce so prominent changes. One may conclude that changes observed in parameters of action potentials of motoneurons are concomitant to changes in contractile properties of MU twitches. This suggests that both modulations of the AHP and twitch parameters reflect mechanisms leading to force development at the beginning of MU activity. PMID:24202237

  13. Molecular transformations in sarcoplasmic reticulum of fast-twitch muscle by electro-stimulation.

    PubMed

    Heilmann, C; Pette, D

    1979-02-01

    Chronic electro-stimulation of fast-twitch rabbit muscle with the frequency pattern received by a slow-twitch muscle induces a progressive transformation of the sarcoplasmic reticulum. After 2 days stimulation activities of Ca2+-dependent ATPase and of Ca2+ transport begin to decrease, and are paralleled by a progressive decrease in Ca2+-dependent and Ca2+, Mg2+-dependent phosphoprotein formation, reduced rate of dephosphorylation and a rearrangement of the electrophoretic polypeptide and phosphoprotein patterns. These findings suggest a transformation of the sarcoplasmic reticulum to resemble that of a slow-twitch muscle. This transformation is paralleled by increase in time-to-peak of twitch contraction and half relaxation time and occurs before conversion of the myosin light chain pattern is observed. The parallel time course of changes in contractile properties of stimulated muscle and the molecular and functional properties of the sarcoplasmic reticulum emphasizes the definitive role of the latter in determining the twitch characteristics of fast and slow twitch muscles. PMID:154404

  14. Differential effects of peroxynitrite on contractile protein properties in fast- and slow-twitch skeletal muscle fibers of rat.

    PubMed

    Dutka, T L; Mollica, J P; Lamb, G D

    2011-03-01

    Oxidative modification of contractile proteins is thought to be a key factor in muscle weakness observed in many pathophysiological conditions. In particular, peroxynitrite (ONOO(-)), a potent short-lived oxidant, is a likely candidate responsible for this contractile dysfunction. In this study ONOO(-) or 3-morpholinosydnonimine (Sin-1, a ONOO(-) donor) was applied to rat skinned muscle fibers to characterize the effects on contractile properties. Both ONOO(-) and Sin-1 exposure markedly reduced maximum force in slow-twitch fibers but had much less effect in fast-twitch fibers. The rate of isometric force development was also reduced without change in the number of active cross bridges. Sin-1 exposure caused a disproportionately large decrease in Ca(2+) sensitivity, evidently due to coproduction of superoxide, as it was prevented by Tempol, a superoxide dismutase mimetic. The decline in maximum force with Sin-1 and ONOO(-) treatments could be partially reversed by DTT, provided it was applied before the fiber was activated. Reversal by DTT indicates that the decrease in maximum force was due at least in part to oxidation of cysteine residues. Ascorbate caused similar reversal, further suggesting that the cysteine residues had undergone S-nitrosylation. The reduction in Ca(2+) sensitivity, however, was not reversed by either DTT or ascorbate. Western blot analysis showed cross-linking of myosin heavy chain (MHC) I, appearing as larger protein complexes after ONOO(-) exposure. The findings suggest that ONOO(-) initially decreases maximum force primarily by oxidation of cysteine residues on the myosin heads, and that the accompanying decrease in Ca(2+) sensitivity is likely due to other, less reversible actions of hydroxyl or related radicals. PMID:21030671

  15. Roles of Pseudomonas aeruginosa las and rhl Quorum-Sensing Systems in Control of Twitching Motility

    PubMed Central

    Glessner, Alex; Smith, Roger S.; Iglewski, Barbara H.; Robinson, Jayne B.

    1999-01-01

    Pseudomonas aeruginosa is a ubiquitous environmental bacterium and an important human pathogen. The production of several virulence factors by P. aeruginosa is controlled through two quorum-sensing systems, las and rhl. We have obtained evidence that both the las and rhl quorum-sensing systems are also required for type 4 pilus-dependent twitching motility and infection by the pilus-specific phage D3112cts. Mutants which lack the ability to synthesize PAI-1, PAI-2, or both autoinducers were significantly or greatly impaired in twitching motility and in susceptibility to D3112cts. Twitching motility and phage susceptibility in the autoinducer-deficient mutants were partially restored by exposure to exogenous PAI-1 and PAI-2. Both twitching motility and infection by pilus-specific phage are believed to be dependent on the extension and retraction of polar type 4 pili. Western blot analysis of whole-cell lysates and enzyme-linked immunosorbent assays of intact cells were used to measure the amounts of pilin on the cell surfaces of las and rhl mutants relative to that of the wild type. It appears that PAI-2 plays a crucial role in twitching motility and phage infection by affecting the export and assembly of surface type 4 pili. The ability of P. aeruginosa cells to adhere to human bronchial epithelial cells was also found to be dependent on the rhl quorum-sensing system. Microscopic analysis of twitching motility indicated that mutants which were unable to synthesize PAI-1 were defective in the maintenance of cellular monolayers and migrating packs of cells. Thus, PAI-1 appears to have an essential role in maintaining cell-cell spacing and associations required for effective twitching motility. PMID:10049396

  16. Adaptation of fibers in fast-twitch muscles of rats to spaceflight and hindlimb suspension

    NASA Technical Reports Server (NTRS)

    Jiang, Bian; Ohira, Yoshi; Roy, Roland R.; Nguyen, Quyet; Il'ina-Kakueva, E. I.; Oganov, V.; Edgerton, V. R.

    1992-01-01

    The adaptation of single fibers in medial gastrocnemius (MG), a fast-twitch extensor, and in tibialis anterior (TA), a fast-twitch flexor, was studied after 14 days of spaceflight onboard Cosmos 2044 or hindlimb suspension. Quantitative myosin ATPase activities of single fibers were measured in flight and suspended rats. Each of the enzyme and size measurements were directly correlated within each fiber with respect to its qualitative myosin ATPase staining properties and its expression of fast, slow, or both myosin heavy chains (MHC). The percentage of slow- and fast-twitch fibers of the MG and TA were found to be unchanged. Mean fiber size of all fibers was unaffected after flight or suspension. The ATPase activity in the MG was higher in flight than in control or suspended rats. In comparison to Cosmos 1887 spaceflight, the adaptations in the muscle fibers of the MG were more moderate.

  17. Effects of lactic acid and catecholamines on contractility in fast-twitch muscles exposed to hyperkalemia.

    PubMed

    Hansen, Anders Krogh; Clausen, Torben; Nielsen, Ole Baekgaard

    2005-07-01

    Intensive exercise is associated with a pronounced increase in extracellular K+ ([K+]o). Because of the ensuing depolarization and loss of excitability, this contributes to muscle fatigue. Intensive exercise also increases the level of circulating catecholamines and lactic acid, which both have been shown to alleviate the depressing effect of hyperkalemia in slow-twitch muscles. Because of their larger exercise-induced loss of K+, fast-twitch muscles are more prone to fatigue caused by increased [K+]o than slow-twitch muscles. Fast-twitch muscles also produce more lactic acid. We therefore compared the effects of catecholamines and lactic acid on the maintenance of contractility in rat fast-twitch [extensor digitorum longus (EDL)] and slow-twitch (soleus) muscles. Intact muscles were mounted on force transducers and stimulated electrically to evoke short isometric tetani. Elevated [K+]o (11 and 13 mM) was used to reduce force to approximately 20% of control force at 4 mM K+. In EDL, the beta2-agonist salbutamol (10(-5) M) restored tetanic force to 83 +/- 2% of control force, whereas in soleus salbutamol restored tetanic force to 93 +/- 1%. In both muscles, salbutamol induced hyperpolarization (5-8 mV), reduced intracellular Na+ content and increased Na+-K+ pump activity, leading to an increased K+ tolerance. Lactic acid (24 mM) restored force from 22 +/- 4% to 58 +/- 2% of control force in EDL, an effect that was significantly lower than in soleus muscle. These results amplify and generalize the concept that the exercise-induced acidification and increase in plasma catecholamines counterbalance fatigue arising from rundown of Na+ and K+ gradients. PMID:15743886

  18. REM sleep twitches rouse nascent cerebellar circuits: Implications for sensorimotor development.

    PubMed

    Sokoloff, Greta; Uitermarkt, Brandt D; Blumberg, Mark S

    2015-10-01

    The cerebellum is critical for sensorimotor integration and undergoes extensive postnatal development. During the first postnatal week in rats, climbing fibers polyinnervate Purkinje cells and, before granule cell migration, mossy fibers make transient, direct connections with Purkinje cells. Activity-dependent processes are assumed to play a critical role in the development and refinement of these and other aspects of cerebellar circuitry. However, the sources and patterning of activity have not been described. We hypothesize that sensory feedback (i.e., reafference) from myoclonic twitches in sleeping newborn rats is a prominent driver of activity for the developing cerebellum. Here, in 6-day-old rats, we show that Purkinje cells exhibit substantial state-dependent changes in complex and simple spike activity-primarily during active sleep. In addition, this activity increases significantly during bouts of twitching. Moreover, the surprising observation of twitch-dependent increases in simple spike activity at this age suggests a functional engagement of mossy fibers before the parallel fiber system has developed. Based on these and other results, we propose that twitching comprises a unique class of self-produced movement that drives critical aspects of activity-dependent development in the cerebellum and other sensorimotor systems. PMID:24677804

  19. Energetics of shortening muscles in twitches and tetanic contractions. II. Force-determined shortening heat.

    PubMed

    Homsher, E; Mommaerts, W F; Ricchiuti, N V

    1973-12-01

    The extra heat liberation accompanying muscular shortening, the force-determined shortening heat, is defined as the difference between the heat produced when shortening occurs and that produced in an isometric contraction developing the same amount of force and performing the same amount of internal work. Based on this definition, the initial energy production in twitches and tetanic contractions (E) is given by E = A + f (P, t) + alpha(F)x + W, where A is the activation heat, f(P, t), the tension-related heat (a heat production associated with the development and maintenance of tension), alpha(F)x, the force-determined shortening heat, and W, the external work. It is demonstrated that this equation accurately accounts for the time-course of heat evolution and the total initial energy production in both twitches and tetani at 0 degrees C. The force-determined shortening heat is liberated, during shortening, in direct proportion to (a) the distance shortened, and (b) the force against which shortening occurs. The normalized value of the force-determined shortening heat coefficient, alpha(F)/P(o), is the same in both the twitch and the tetanus. Finally, this formulation of the muscle's energy production also accounts for the total energy production in afterload isotonic twitches at 20 degrees C, where a Fenn effect is not demonstrable. PMID:4548714

  20. Relationship between transdiaphragmatic and mouth twitch pressures at functional residual capacity.

    PubMed

    Laghi, F; Tobin, M J

    1997-03-01

    The clinical application of transdiaphragmatic twitch pressure (Pdi,tw) response to phrenic nerve stimulation has been hindered by the requirement for placement of oesophageal and gastric balloons. Investigators have reported that mouth twitch pressure (Pmo,tw) estimates Pdi,tw accurately at lung volumes above and below functional residual capacity (FRC). However, it is not known whether Pmo,tw estimates Pdi,tw accurately when stimulation is performed at FRC during relaxed conditions. The aim of this study was to develop a simple method whereby measurements of Pmo could be used to predict oesophageal twitch pressure (Poes,tw) and possibly Pdi,tw at FRC. The study was performed in 11 healthy volunteers during phrenic nerve stimulation. At FRC, 9 of the 11 subjects showed a poor correlation between Pmo,tw and Poes,tw, and between Pmo,tw and Pdi,tw, probably due to varying degrees of glottic closure. Stimulations performed while subjects maintained an inspiratory flow of approximately 50 mL x s(-1), or at the point of reattaining FRC during an inspiration preceded by a limited exhalation, produced good correlations between Pmo,tw and Poes,tw (r=0.97 in both instances) and Pmo,tw and Pdi,tw (r=0.96 and r=0.95, respectively), with a steep slope. The respective slopes for the Pmo,tw Poes,tw relationship were 0.88 and 0.94, and for the Pmo,tw Pdi,tw relationship, 0.59 and 0.54. Unfortunately, these manoeuvres produced a significant increase in transpulmonary pressure (3.6+/-0.6 (SE) and 5.6+/-1.4 cmH2O, respectively), suggesting change in diaphragmatic length. Stimulations delivered while subjects performed an inspiratory effort or during exhalation against a high resistance preceded by a limited inhalation could not be used to predict Poes,tw and Pdi,tw from Pmo,tw. In conclusion, although transdiaphragmatic and oesophageal twitch pressure could be predicted from mouth twitch pressure during some inspiratory manoeuvres mouth twitch pressure was not reliable for the

  1. Motor units in cross-reinnervated fast and slow twitch muscle of the cat.

    PubMed Central

    Bagust, J; Lewis, D M; Westerman, R A

    1981-01-01

    1. Isometric contractile properties of motor units were measured in cross-reinnervated fast (flexor digitorum longus) and slow (soleus) twitch muscles of the cat. All but one cross was at least 95% pure. 2. There was a reduction in the number of motor units in all muscles, but totals remained about equal in cross-reinnervated soleus and flexor digitorum longus. 3. Motor unit tensions (mean and maximum values) were higher in cross-reinnervated soleus than in cross-reinnervated flexor digitorum longus, reversing the differences between normal muscles. This was due to increases in muscle mass and in the tension developed per unit cross-sectional area. There were motor unit tensions larger and smaller than those seen in normal muscle, but the range was comparable with that seen in self-reinnervated muscle. 4. The changes in twitch time to peak of whole muscle following cross-reinnervations resulted from a change over the whole range of motor units. The conversion of soleus was less complete than that of flexor digitorum longus, and the time to peak of its fastest motor unit was twice as long as any seen in normal flexor digitorum longus. 5. In neither of the cross-reinnervated muscles were the fast contracting motor units larger than the slow contracting ones, and in cross-reinnervated soleus they were smaller. 6. Axonal conduction velocity was correlated with motor unit tension in both muscles and with twitch time to peak in cross-reinnervated flexor digitorum longus, but in all cases less clearly than in normal muscles. 7. The ratio of twitch to tetanic tension increased with increasing twitch time to peak, as in normal muscles. PMID:7277217

  2. Visualization of Twitching Motility and Characterization of the Role of the PilG in Xylella fastidiosa.

    PubMed

    Shi, Xiangyang; Lin, Hong

    2016-01-01

    Xylella fastidiosa is a Gram-negative non-flagellated bacterium that causes a number of economically important diseases of plants. The twitching motility provides X. fastidiosa a means for long-distance intra-plant movement and colonization, contributing toward pathogenicity in X. fastidiosa. The twitching motility of X. fastidiosa is operated by type IV pili. Type IV pili of Xylella fastidiosa are regulated by pilG, a chemotaxis regulator in Pil-Chp operon encoding proteins that are involved with signal transduction pathways. To elucidate the roles of pilG in the twitching motility of X. fastidiosa, a pilG-deficient mutant XfΔpilG and its complementary strain XfΔpilG-C containing native pilG were developed. A microfluidic chambers integrated with a time-lapse image recording system was used to observe twitching motility in XfΔpilG, XfΔpilG-C and its wild type strain. Using this recording system, it permits long-term spatial and temporal observations of aggregation, migration of individual cells and populations of bacteria via twitching motility. X. fastidiosa wild type and complementary XfΔpilG-C strain showed typical twitching motility characteristics directly observed in the microfluidic flow chambers, whereas mutant XfΔpliG exhibited the twitching deficient phenotype. This study demonstrates that pilG contributes to the twitching motility of X. fastidiosa. The microfluidic flow chamber is used as a means for observing twitching motility. PMID:27166660

  3. Effects of age on calcium transport activity of sarcoplasmic reticulum in fast- and slow-twitch rat muscle fibres.

    PubMed Central

    Larsson, L; Salviati, G

    1989-01-01

    1. The calcium transport activity of the sarcoplasmic reticulum (SR) was measured in chemically skinned single fast- and slow-twitch muscle fibres from young (3 months) and old (23-24 months) rats. Contractile properties, the myosin heavy chain (MHC) composition and enzyme histochemical features were studied in relation to the SR characteristics. 2. In fast-twitch single motor units, the contraction time of the isometric twitch increased (P less than 0.001) from 13 +/- 1 ms in young animals to 18 +/- 2 ms in old ones. In the slow-twitch soleus, the contraction (P less than 0.001) and half-relaxation (P less than 0.05) times increased from 30 +/- 5 and 45 +/- 10 ms, respectively, in the young animals to 43 +/- 3 and 55 +/- 4 ms in the old ones. The proportion of slow-twitch (type I) fibres increased (P less than 0.05) with age in the soleus from 92 +/- 6 to 98 +/- 2% and the proportion of fast-twitch fibres (type IIA) decreased (P less than 0.01) from 6 +/- 5 to 0 +/- 0%. 3. The Ca2+ accumulation capacity (an index of SR volume), the rate of Ca2+ uptake and the fractional rate of SR filling (an estimate of the specific activity of the Ca2+ pump) were decreased by 18 (P less than 0.05), 32 (P less than 0.01) and 32% (P less than 0.001), respectively, in the old fast-twitch muscle fibres. In the slow-twitch muscle fibres, on the other hand, no significant age-related changes were observed in the Ca2+ transport activity of the SR. Thus, ageing exerts a differential influence on SR volume and function in fast- and slow-twitch fibres. 4. It is concluded that an age-related impairment of intrinsic SR function and a decrease in SR volume are probable factors underlying the decreased speed of contraction of fast-twitch muscle fibres in old age. In the slow-twitch soleus, on the other hand, one or more other mechanisms are responsible for the age-related decrease in the speed of contraction. The loss of fast-twitch muscle fibres in old soleus is one mechanism, but not the

  4. Twitching motility and possession of polar fimbriae in spreading Streptococcus sanguis isolates from the human throat.

    PubMed

    Henriksen, S D; Henrichsen, J

    1975-04-01

    A collection of 19 strains of alpha haemolytic streptococci, isolated from throat swabs and characterized by production of spreading zones around colonies on blood agar, was found to constitute a very homogeneous group with morphological, physiological and biochemical characters corresponding to those of streptococci of ser-group H, or Streptococcus sanguis, and they all appeared to possess the group H antigen. They all had a common agglutinogen and, in addition, heterogeneous agglutinogens. The spreading growth, which appears to be a common property of S. sanguis, was due to twitching motility, and the spreading cultures possessed polar fimbriae. tneither twitching motility nor the possession of polar fimbriae have been observed in gram-positive bacteria before. PMID:1171576

  5. Quantifying Spatiotemporal Patterns in the Advancing Front of Twitching Bacterial Colonies

    NASA Astrophysics Data System (ADS)

    Shelton, Erin; Giuliani, Max; Burrows, Lori; Dutcher, John

    Type IV pili (T4P) are very thin (5-8 nm in diameter) protein filaments that can be extended and retracted by certain classes of Gram-negative bacteria including P. aeruginosa. These bacteria use T4P to move across viscous interfaces, referred to twitching motility. Twitching can occur for isolated cells or in a collective manner. Using a custom-built, temperature and humidity controlled environmental chamber, together with particle image velocimetry and Fourier analysis techniques, we characterized the evolution of the advancing front of expanding colonies. We find that the advancing front consists of finger-like protrusions consisting of many bacteria, with the cells within the expanding colony arranged in a lattice-like pattern. We have characterized the average speed, width and bacterial orientation within the fingers as a function of agar concentration/stiffness. In addition, we have analyzed the motion of individual cells within the fingers at high spatial and temporal resolution.

  6. Streptozotocin-induced diabetes prolongs twitch duration without affecting the energetics of isolated ventricular trabeculae

    PubMed Central

    2014-01-01

    Background Diabetes induces numerous electrical, ionic and biochemical defects in the heart. A general feature of diabetic myocardium is its low rate of activity, commonly characterised by prolonged twitch duration. This diabetes-induced mechanical change, however, seems to have no effect on contractile performance (i.e., force production) at the tissue level. Hence, we hypothesise that diabetes has no effect on either myocardial work output or heat production and, consequently, the dependence of myocardial efficiency on afterload of diabetic tissue is the same as that of healthy tissue. Methods We used isolated left ventricular trabeculae (streptozotocin-induced diabetes versus control) as our experimental tissue preparations. We measured a number of indices of mechanical (stress production, twitch duration, extent of shortening, shortening velocity, shortening power, stiffness, and work output) and energetic (heat production, change of enthalpy, and efficiency) performance. We calculated efficiency as the ratio of work output to change of enthalpy (the sum of work and heat). Results Consistent with literature results, we showed that peak twitch stress of diabetic tissue was normal despite suffering prolonged duration. We report, for the first time, the effect of diabetes on mechanoenergetic performance. We found that the indices of performance listed above were unaffected by diabetes. Hence, since neither work output nor change of enthalpy was affected, the efficiency-afterload relation of diabetic tissue was unaffected, as hypothesised. Conclusions Diabetes prolongs twitch duration without having an effect on work output or heat production, and hence efficiency, of isolated ventricular trabeculae. Collectively, our results, arising from isolated trabeculae, reconcile the discrepancy between the mechanical performance of the whole heart and its tissues. PMID:24731754

  7. Twitching motility and cAMP levels: signal transduction through a single methyl-accepting chemotaxis protein.

    PubMed

    Jansari, Vibhuti H; Potharla, Vishwakanth Y; Riddell, Geoff T; Bardy, Sonia L

    2016-06-01

    The Pseudomonas aeruginosa Chp chemosensory system regulates twitching motility, intracellular adenosine 3('') 5(')-cyclic monophosphate (cAMP) levels and is postulated to be involved in directional twitching towards phosphatidylethanolamine (PE). Because PilJ is the only methyl-accepting chemotaxis protein (MCP) identified in the Chp system, we determined the role of PilJ in mediating signal transduction for the distinct outputs of this system. Mutants that lack the periplasmic domain of PilJ (pilJΔ74-273) showed lower levels of cAMP but retained directional twitching towards PE. While initial studies revealed reduced twitching motility by PilJΔ74-273, this was due to decreased cAMP levels. Our data illustrate the importance of the periplasmic domain of PilJ in regulating cAMP. This is the first time a defined domain within PilJ has been identified as having a distinct role in signal transduction. PMID:27190147

  8. Exercise myopathy: changes in myofibrils of fast-twitch muscle fibres.

    PubMed

    Kaasik, P; Umnova, M; Seene, T

    2014-08-01

    The purpose of the present study was to determine the relationships between the changes of myofibrils in fast-twitch oxidative-glycolytic (type IIA) fibres and fast-twitch glycolytic (type IIB) muscle fibres, protein synthesis and degradation rate in exercise-induced myopathic skeletal muscle. Exhaustive exercise was used to induce myopathy in Wistar rats. Intensity of glycogenolysis in muscle fibres during exercise, protein synthesis rate, degradation rate and structural changes of myofibrils were measured using morphological and biochemical methods. Myofibril cross sectional area (CSA) in type IIA fibres decreased 33% and type IIB fibres 44%. Protein degradation rate increased in both type IIA and IIB fibres, 63% and 69% respectively in comparison with the control group. According to the intensity of glycogenolysis, fast oxidative-glycolytic fibres are recruited more frequently during overtraining. Myofibrils in both types of fast-twitch myopathic muscle fibres are significantly thinner as the result of more intensive protein degradation. Regeneration capacity according to the presence of satellite cells is higher in type IIA fibres than in type IIB fibres in myopathic muscle. PMID:25177093

  9. Validity of the twitch interpolation technique for the assessment of quadriceps neuromuscular asymmetries.

    PubMed

    Maffiuletti, Nicola Angelo; Barbero, Marco; Cescon, Corrado; Clijsen, Ron; Beretta-Piccoli, Matteo; Schneebeli, Alessandro; Preiss, Stefan; Togninalli, Danilo

    2016-06-01

    This study examined the validity of the twitch interpolation technique for evaluating side-to-side asymmetries in quadriceps neuromuscular function. Fifty-six subjects with a wide range of asymmetries (19 healthy, 24 with unilateral and 13 with bilateral anterior cruciate ligament reconstruction) took part in the study. Supramaximal electrical paired stimuli were delivered to the quadriceps muscle during and immediately after a maximal voluntary contraction (MVC) of the knee extensors (twitch interpolation technique). MVC torque, voluntary activation and resting doublet-evoked torque were measured separately for the two sides, and percent side-to-side asymmetries were calculated for each parameter. MVC torque asymmetry was plotted against voluntary activation asymmetry and doublet-evoked torque asymmetry, and a multiple regression analysis was also conducted. Significant positive correlations were observed between MVC torque asymmetry and both voluntary activation asymmetry (r=0.40; p=0.002) and doublet-evoked torque asymmetry (r=0.53; p<0.001), and their relative contribution to MVC torque asymmetry was comparable (r=0.64; p<0.001). These results establish the validity of the twitch interpolation technique for the assessment of neuromuscular asymmetries. This methodology could provide useful insights into the contribution of some neural and muscular mechanisms that underlie quadriceps strength deficits. PMID:26990615

  10. Role of the JP45-Calsequestrin Complex on Calcium Entry in Slow Twitch Skeletal Muscles*

    PubMed Central

    Mosca, Barbara; Eckhardt, Jan; Bergamelli, Leda; Treves, Susan; Bongianino, Rossana; De Negri, Marco; Priori, Silvia G.; Protasi, Feliciano; Zorzato, Francesco

    2016-01-01

    We exploited a variety of mouse models to assess the roles of JP45-CASQ1 (CASQ, calsequestrin) and JP45-CASQ2 on calcium entry in slow twitch muscles. In flexor digitorum brevis (FDB) fibers isolated from JP45-CASQ1-CASQ2 triple KO mice, calcium transients induced by tetanic stimulation rely on calcium entry via La3+- and nifedipine-sensitive calcium channels. The comparison of excitation-coupled calcium entry (ECCE) between FDB fibers from WT, JP45KO, CASQ1KO, CASQ2KO, JP45-CASQ1 double KO, JP45-CASQ2 double KO, and JP45-CASQ1-CASQ2 triple KO shows that ECCE enhancement requires ablation of both CASQs and JP45. Calcium entry activated by ablation of both JP45-CASQ1 and JP45-CASQ2 complexes supports tetanic force development in slow twitch soleus muscles. In addition, we show that CASQs interact with JP45 at Ca2+ concentrations similar to those present in the lumen of the sarcoplasmic reticulum at rest, whereas Ca2+ concentrations similar to those present in the SR lumen after depolarization-induced calcium release cause the dissociation of JP45 from CASQs. Our results show that the complex JP45-CASQs is a negative regulator of ECCE and that tetanic force development in slow twitch muscles is supported by the dynamic interaction between JP45 and CASQs. PMID:27189940

  11. Role of the JP45-Calsequestrin Complex on Calcium Entry in Slow Twitch Skeletal Muscles.

    PubMed

    Mosca, Barbara; Eckhardt, Jan; Bergamelli, Leda; Treves, Susan; Bongianino, Rossana; De Negri, Marco; Priori, Silvia G; Protasi, Feliciano; Zorzato, Francesco

    2016-07-01

    We exploited a variety of mouse models to assess the roles of JP45-CASQ1 (CASQ, calsequestrin) and JP45-CASQ2 on calcium entry in slow twitch muscles. In flexor digitorum brevis (FDB) fibers isolated from JP45-CASQ1-CASQ2 triple KO mice, calcium transients induced by tetanic stimulation rely on calcium entry via La(3+)- and nifedipine-sensitive calcium channels. The comparison of excitation-coupled calcium entry (ECCE) between FDB fibers from WT, JP45KO, CASQ1KO, CASQ2KO, JP45-CASQ1 double KO, JP45-CASQ2 double KO, and JP45-CASQ1-CASQ2 triple KO shows that ECCE enhancement requires ablation of both CASQs and JP45. Calcium entry activated by ablation of both JP45-CASQ1 and JP45-CASQ2 complexes supports tetanic force development in slow twitch soleus muscles. In addition, we show that CASQs interact with JP45 at Ca(2+) concentrations similar to those present in the lumen of the sarcoplasmic reticulum at rest, whereas Ca(2+) concentrations similar to those present in the SR lumen after depolarization-induced calcium release cause the dissociation of JP45 from CASQs. Our results show that the complex JP45-CASQs is a negative regulator of ECCE and that tetanic force development in slow twitch muscles is supported by the dynamic interaction between JP45 and CASQs. PMID:27189940

  12. Muscle Fatigue Affects the Interpolated Twitch Technique When Assessed Using Electrically-Induced Contractions in Human and Rat Muscles

    PubMed Central

    Neyroud, Daria; Cheng, Arthur J.; Bourdillon, Nicolas; Kayser, Bengt; Place, Nicolas; Westerblad, Håkan

    2016-01-01

    The interpolated twitch technique (ITT) is the gold standard to assess voluntary activation and central fatigue. Yet, its validity has been questioned. Here we studied how peripheral fatigue can affect the ITT. Repeated contractions at submaximal frequencies were produced by supramaximal electrical stimulations of the human adductor pollicis muscle in vivo and of isolated rat soleus fiber bundles; an extra stimulation pulse was given during contractions to induce a superimposed twitch. Human muscles fatigued by repeated 30-Hz stimulation trains (3 s on–1 s off) showed an ~80% reduction in the superimposed twitch force accompanied by a severely reduced EMG response (M-wave amplitude), which implies action potential failure. Subsequent experiments combined a less intense stimulation protocol (1.5 s on–3 s off) with ischemia to cause muscle fatigue, but which preserved M-wave amplitude. However, the superimposed twitch force still decreased markedly more than the potentiated twitch force; with ITT this would reflect increased “voluntary activation.” In contrast, the superimposed twitch force was relatively spared when a similar protocol was performed in rat soleus bundles. Force relaxation was slowed by >150% in fatigued human muscles, whereas it was unchanged in rat soleus bundles. Accordingly, results similar to those in the human muscle were obtained when relaxation was slowed by cooling the rat soleus muscles. In conclusion, our data demonstrate that muscle fatigue can confound the quantification of central fatigue using the ITT.

  13. Effect of prolonged depolarizations on twitch tension and intracellular sodium activity in sheep cardiac Purkinje fibres.

    PubMed Central

    Brill, D M; Fozzard, H A; Makielski, J C; Wasserstrom, J A

    1987-01-01

    1. Twitch tension and intracellular Na+ activity (aiNa) were measured in voltage-clamped sheep cardiac Purkinje fibres. aiNa was measured using Na+-sensitive micro-electrodes filled with the liquid ion exchange resin. ETH 227. The stimulus for contraction was a constant 200 ms depolarizing pulse to 0 mV from a holding potential of -80 mV delivered at 0.25 Hz. Prolonged test pulses for 1.8 s (post-pulses) were applied at the end of the stimulus pulse. The effects of post-pulses on twitch tension and aiNa were examined. 2. Post-pulses in the range of -40 mV reduced twitch tension below control force produced without post-pulse. Progressively more positive post-pulses to levels above 0 mV profoundly increased twitch tension, with a greater than 400% rise in tension at +50 to +60 mV compared to control tension. aiNa declined at positive post-pulse potentials by more than 2 mM at +30 to +40 mV. 3. Tetrodotoxin (100 microM) did not affect the post-pulse voltage-tension or voltage-aiNa relation. Ca2+ channel modulation with nitrendipine (1 microM) similarly did not alter the post-pulse voltage-tension relation. 4. Removal of extracellular Na+ eliminated the nadir in tension at post-pulses to -40 mV and the augmentation of tension at post-pulses above 0 mV. 5. We interpret these findings as evidence of voltage-sensitive Na-Ca exchange promoting net Ca2+ influx and net Na+ efflux during positive post-pulses. The unusual shape of the post-pulse voltage-tension relation curve can be accounted for by a charged-carrier model of electrogenic Na-Ca exchange. The inverse relation between aiNa and twitch tension probably reflects the combined effects of reduced aiNa leak and changes in Na+ and Ca2+ flux via voltage-sensitive Na-Ca exchange. PMID:2443661

  14. Heads Up

    MedlinePlus

    ... Juvenil HEADS UP to School Sports Online Concussion Training Coaches Parents Athletes Sports Officials HEADS UP to Schools School Nurses Teachers, Counselors, and School Professionals Parents HEADS UP ...

  15. Diastolic scattered light fluctuation, resting force and twitch force in mammalian cardiac muscle

    PubMed Central

    Lakatta, E. G.; Lappé, D. L.

    1981-01-01

    1. When coherent light was passed through isolated isometric cardiac muscles during the diastolic or resting period, intensity fluctuations were observed in the scattered field. The frequency of these intensity fluctuations (f½) varied with many experimental interventions known to enhance Ca2+ flux into the cell. 2. In rat muscles stimulated at low frequencies (0.1 ± 2.0 min-1) stepwise increases (0.4-10 mm) of [Ca2+] in the bathing fluid ([Ca2+]e), or addition of ouabain (10-6-6 × 10-4 m) to the perfusate caused stepwise increases in f½. These were paralleled by increments in resting force (RF) such that the changes in f½ and RF were highly correlated. Substitution of K+ for Na+ in the perfusate resulted in parallel transients in RF and f½. 3. In contrast to the rat, most cat muscles stimulated at low frequencies in the steady state exhibited neither diastolic intensity fluctuations nor Ca2+-dependent changes in RF in [Ca2+]e of 10 mm or less; when [Ca2+]e was increased to 12-32 mm, however, steady-state Ca2+-dependent f½ and RF were observed. In a given [Ca2+]e reduction of [Na+]e increased f½. In the transient state following cessation of regular stimulation at more rapid rates (12-96 min-1) intensity fluctuations were present in all [Ca2+]e and decayed with time (seconds to minutes); the f½ and time course of the decay of the fluctuations were determined by the rate of prior stimulation and [Ca2+]e. 4. Maximum potentiation of twitch force in response to the above inotropic interventions was associated with an optimal level of f½ which was similar in both species; when higher levels of f½ were produced by more intense inotropic intervention, twitch force declined. Over the range of inotropic intervention up to and including that at which maximum twitch potentiation occurred, the increase in diastolic f½ predicted the extent of twitch potentiation with a high degree of accuracy (r > 0.97) both in the transient and steady states. 5. In contrast to the

  16. Twitch-related and rhythmic activation of the developing cerebellar cortex.

    PubMed

    Sokoloff, Greta; Plumeau, Alan M; Mukherjee, Didhiti; Blumberg, Mark S

    2015-09-01

    The cerebellum is a critical sensorimotor structure that exhibits protracted postnatal development in mammals. Many aspects of cerebellar circuit development are activity dependent, but little is known about the nature and sources of the activity. Based on previous findings in 6-day-old rats, we proposed that myoclonic twitches, the spontaneous movements that occur exclusively during active sleep (AS), provide generalized as well as topographically precise activity to the developing cerebellum. Taking advantage of known stages of cerebellar cortical development, we examined the relationship between Purkinje cell activity (including complex and simple spikes), nuchal and hindlimb EMG activity, and behavioral state in unanesthetized 4-, 8-, and 12-day-old rats. AS-dependent increases in complex and simple spike activity peaked at 8 days of age, with 60% of units exhibiting significantly more activity during AS than wakefulness. Also, at all three ages, approximately one-third of complex and simple spikes significantly increased their activity within 100 ms of twitches in one of the two muscles from which we recorded. Finally, we observed rhythmicity of complex and simple spikes that was especially prominent at 8 days of age and was greatly diminished by 12 days of age, likely due to developmental changes in climbing fiber and mossy fiber innervation patterns. All together, these results indicate that the neurophysiological activity of the developing cerebellum can be used to make inferences about changes in its microcircuitry. They also support the hypothesis that sleep-related twitches are a prominent source of discrete climbing and mossy fiber activity that could contribute to the activity-dependent development of this critical sensorimotor structure. PMID:26156383

  17. Numerical Simulation of the Twitching Motility of Bacterium Crawling on a Solid Surface

    NASA Astrophysics Data System (ADS)

    Morikawa, Ryota; Tamakoshi, Masatada; Miyakawa, Takeshi; Takasu, Masako

    A dynamics model of bacterial twitching motility is devised. A bacterial body is bound on a plane surface and driven by multiple type IV pili (TFP) which are appendages of the bacterium. The drag force following Stokes' law also applies to the bacterial body in the viscous fluid. By using the individual model, the numerical simulations are performed and the velocities and the rotational velocity of the bacterial body are investigated. From the results of the simulations, a rapid motion with rotationcalled slingshot, which was found in P. aeruginosa, is reproduced. There is a possibility that the slingshot motion may be carried out widely in many species of bacteria having TFP.

  18. Research on Acute Toxicity and the Behavioral Effects of Methanolic Extract from Psilocybin Mushrooms and Psilocin in Mice

    PubMed Central

    Zhuk, Olga; Jasicka-Misiak, Izabela; Poliwoda, Anna; Kazakova, Anastasia; Godovan, Vladlena V.; Halama, Marek; Wieczorek, Piotr P.

    2015-01-01

    The pharmacological activities and acute toxicity of the psilocin (PC) and dried residues of the crude extracts of psychotropic mushrooms were investigated in mice. The hallucinogenic substances were effectively isolated, by using methanol, from the species of Psilocybe semilanceata and Pholiotina cyanopus, that were collected in the north-east region of Poland. The chemical analysis of these extracts, which was performed by liquid chromatography with mass spectrometry detection (LC-MS), indicated the presence of psilocin and other hallucinogenic substances, including indolealkylamines and their phosphorylated analogues. When the pure psilocin or fungal extracts were used, slight differences in determined LD50 values were observed. However, the application of PC evoked the highest level of toxicity (293.07 mg/kg) compared to the activity of extracts from Ph. cyanopus and P. semilanceata, where the level of LD50 was 316.87 mg/kg and 324.37 mg/kg, respectively. Furthermore, the behavioral test, which considered the head-twitching response (HTR), was used to assess the effects of the studied psychotropic factors on the serotonergic system. Both, the fungal extracts and psilocin evoked characteristic serotoninergic effects depending on the dose administered to mice, acting as an agonist/partial agonist on the serotonergic system. A dose of 200 mg/kg 5-hydroxytryptophan (5-HTP) induced spontaneous head-twitching in mice (100% effect), as a result of the formation of 5-hydroxytryptamine (5-HT) in the brain. Compared to the activity of 5-HTP, the intraperitoneal administration of 1mg/kg of psilocin or hallucinogenic extracts of studied mushrooms (Ph. cyanopus and P. semilanceata) reduced the number of head-twitch responses of about 46% and 30%, respectively. In contrast, the administration of PC exhibited a reduction of about 60% in HTR numbers. PMID:25826052

  19. Research on acute toxicity and the behavioral effects of methanolic extract from psilocybin mushrooms and psilocin in mice.

    PubMed

    Zhuk, Olga; Jasicka-Misiak, Izabela; Poliwoda, Anna; Kazakova, Anastasia; Godovan, Vladlena V; Halama, Marek; Wieczorek, Piotr P

    2015-04-01

    The pharmacological activities and acute toxicity of the psilocin (PC) and dried residues of the crude extracts of psychotropic mushrooms were investigated in mice. The hallucinogenic substances were effectively isolated, by using methanol, from the species of Psilocybe semilanceata and Pholiotina cyanopus, that were collected in the north-east region of Poland. The chemical analysis of these extracts, which was performed by liquid chromatography with mass spectrometry detection (LC-MS), indicated the presence of psilocin and other hallucinogenic substances, including indolealkylamines and their phosphorylated analogues. When the pure psilocin or fungal extracts were used, slight differences in determined LD50 values were observed. However, the application of PC evoked the highest level of toxicity (293.07 mg/kg) compared to the activity of extracts from Ph. cyanopus and P. semilanceata, where the level of LD50 was 316.87 mg/kg and 324.37 mg/kg, respectively. Furthermore, the behavioral test, which considered the head-twitching response (HTR), was used to assess the effects of the studied psychotropic factors on the serotonergic system. Both, the fungal extracts and psilocin evoked characteristic serotoninergic effects depending on the dose administered to mice, acting as an agonist/partial agonist on the serotonergic system. A dose of 200 mg/kg 5-hydroxytryptophan (5-HTP) induced spontaneous head-twitching in mice (100% effect), as a result of the formation of 5-hydroxytryptamine (5-HT) in the brain. Compared to the activity of 5-HTP, the intraperitoneal administration of 1mg/kg of psilocin or hallucinogenic extracts of studied mushrooms (Ph. cyanopus and P. semilanceata) reduced the number of head-twitch responses of about 46% and 30%, respectively. In contrast, the administration of PC exhibited a reduction of about 60% in HTR numbers. PMID:25826052

  20. Development of a Novel Method for Analyzing Pseudomonas aeruginosa Twitching Motility and Its Application to Define the AmrZ Regulon.

    PubMed

    Xu, Binjie; Wozniak, Daniel J

    2015-01-01

    Twitching motility is an important migration mechanism for the Gram-negative bacterium Pseudomonas aeruginosa. In the commonly used subsurface twitching assay, the sub-population of P. aeruginosa with active twitching motility is difficult to harvest for high-throughput studies. Here we describe the development of a novel method that allows efficient isolation of bacterial sub-populations conducting highly active twitching motility. The transcription factor AmrZ regulates multiple P. aeruginosa virulence factors including twitching motility, yet the mechanism of this activation remains unclear. We therefore set out to understand this mechanism by defining the AmrZ regulon using DNA microarrays in combination with the newly developed twitching motility method. We discovered 112 genes in the AmrZ regulon and many encode virulence factors. One gene of interest and the subsequent focus was lecB, which encodes a fucose-binding lectin. DNA binding assays revealed that AmrZ activates lecB transcription by directly binding to its promoter. The lecB gene was previously shown to be required for twitching motility in P. aeruginosa strain PAK; however, our lecB deletion had no effect on twitching motility in strain PAO1. Collectively, in this study a novel condition was developed for quantitative studies of twitching motility, under which the AmrZ regulon was defined. PMID:26309248

  1. Development of a Novel Method for Analyzing Pseudomonas aeruginosa Twitching Motility and Its Application to Define the AmrZ Regulon

    PubMed Central

    Xu, Binjie; Wozniak, Daniel J.

    2015-01-01

    Twitching motility is an important migration mechanism for the Gram-negative bacterium Pseudomonas aeruginosa. In the commonly used subsurface twitching assay, the sub-population of P. aeruginosa with active twitching motility is difficult to harvest for high-throughput studies. Here we describe the development of a novel method that allows efficient isolation of bacterial sub-populations conducting highly active twitching motility. The transcription factor AmrZ regulates multiple P. aeruginosa virulence factors including twitching motility, yet the mechanism of this activation remains unclear. We therefore set out to understand this mechanism by defining the AmrZ regulon using DNA microarrays in combination with the newly developed twitching motility method. We discovered 112 genes in the AmrZ regulon and many encode virulence factors. One gene of interest and the subsequent focus was lecB, which encodes a fucose-binding lectin. DNA binding assays revealed that AmrZ activates lecB transcription by directly binding to its promoter. The lecB gene was previously shown to be required for twitching motility in P. aeruginosa strain PAK; however, our lecB deletion had no effect on twitching motility in strain PAO1. Collectively, in this study a novel condition was developed for quantitative studies of twitching motility, under which the AmrZ regulon was defined. PMID:26309248

  2. Different effects of raised [K+]o on membrane potential and contraction in mouse fast- and slow-twitch muscle.

    PubMed

    Cairns, S P; Hing, W A; Slack, J R; Mills, R G; Loiselle, D S

    1997-08-01

    Increasing extracellular K+ concentration ([K+]o) from 4 to 7-14 mM reduced both tetanic force and resting membrane potential (Em) in isolated slow-twitch soleus and fast-twitch extensor digitorum longus (EDL) muscles of the mouse. The tetanic force-[K+]o relationships showed a greater force loss over 8-11 mM [K+]o in soleus than EDL, mainly because the Em was 2-3 mV less negative at each [K+]o in soleus. The tetanic force-resting Em relationships show that force was reduced in two phases: phase 1 (Em < -60 mV), a 20% force decline in which the relationships superimposed in soleus and EDL, and phase 2 (Em -60 to -55 mV), a marked force decline that was steeper in EDL than soleus. Additionally in phase 2, longer stimulation pulses restored tetanic force; the twitch force-stimulation strength relationship was shifted toward higher voltages; caffeine, a myoplasmic Ca2+ concentration elevator, increased maximum force; and twitch force fell abruptly. We suggest that 1) the K(+)-depressed force is due to reduced Ca2+ release resulting from an altered action potential profile (phase 1) and inexcitable fibers due to an increased action potential threshold (phase 2), and 2) K+ contributes to fatigue in both fast- and slow-twitch muscle when it causes depolarization to about -60 mV. PMID:9277357

  3. Uncovering the mechanism of trapping and cell orientation during Neisseria gonorrhoeae twitching motility.

    PubMed

    Zaburdaev, Vasily; Biais, Nicolas; Schmiedeberg, Michael; Eriksson, Jens; Jonsson, Ann-Beth; Sheetz, Michael P; Weitz, David A

    2014-10-01

    Neisseria gonorrheae bacteria are the causative agent of the second most common sexually transmitted infection in the world. The bacteria move on a surface by means of twitching motility. Their movement is mediated by multiple long and flexible filaments, called type IV pili, that extend from the cell body, attach to the surface, and retract, thus generating a pulling force. Moving cells also use pili to aggregate and form microcolonies. However, the mechanism by which the pili surrounding the cell body work together to propel bacteria remains unclear. Understanding this process will help describe the motility of N. gonorrheae bacteria, and thus the dissemination of the disease which they cause. In this article we track individual twitching cells and observe that their trajectories consist of alternating moving and pausing intervals, while the cell body is preferably oriented with its wide side toward the direction of motion. Based on these data, we propose a model for the collective pili operation of N. gonorrheae bacteria that explains the experimentally observed behavior. Individual pili function independently but can lead to coordinated motion or pausing via the force balance. The geometry of the cell defines its orientation during motion. We show that by changing pili substrate interactions, the motility pattern can be altered in a predictable way. Although the model proposed is tangibly simple, it still has sufficient robustness to incorporate further advanced pili features and various cell geometries to describe other bacteria that employ pili to move on surfaces. PMID:25296304

  4. Transcriptional co-activator PGC-1 alpha drives the formation of slow-twitch muscle fibres.

    PubMed

    Lin, Jiandie; Wu, Hai; Tarr, Paul T; Zhang, Chen-Yu; Wu, Zhidan; Boss, Olivier; Michael, Laura F; Puigserver, Pere; Isotani, Eiji; Olson, Eric N; Lowell, Bradford B; Bassel-Duby, Rhonda; Spiegelman, Bruce M

    2002-08-15

    The biochemical basis for the regulation of fibre-type determination in skeletal muscle is not well understood. In addition to the expression of particular myofibrillar proteins, type I (slow-twitch) fibres are much higher in mitochondrial content and are more dependent on oxidative metabolism than type II (fast-twitch) fibres. We have previously identified a transcriptional co-activator, peroxisome-proliferator-activated receptor-gamma co-activator-1 (PGC-1 alpha), which is expressed in several tissues including brown fat and skeletal muscle, and that activates mitochondrial biogenesis and oxidative metabolism. We show here that PGC-1 alpha is expressed preferentially in muscle enriched in type I fibres. When PGC-1 alpha is expressed at physiological levels in transgenic mice driven by a muscle creatine kinase (MCK) promoter, a fibre type conversion is observed: muscles normally rich in type II fibres are redder and activate genes of mitochondrial oxidative metabolism. Notably, putative type II muscles from PGC-1 alpha transgenic mice also express proteins characteristic of type I fibres, such as troponin I (slow) and myoglobin, and show a much greater resistance to electrically stimulated fatigue. Using fibre-type-specific promoters, we show in cultured muscle cells that PGC-1 alpha activates transcription in cooperation with Mef2 proteins and serves as a target for calcineurin signalling, which has been implicated in slow fibre gene expression. These data indicate that PGC-1 alpha is a principal factor regulating muscle fibre type determination. PMID:12181572

  5. Xanthomonas citri subsp. citri type IV Pilus is required for twitching motility, biofilm development, and adherence.

    PubMed

    Dunger, German; Guzzo, Cristiane R; Andrade, Maxuel O; Jones, Jeffrey B; Farah, Chuck S

    2014-10-01

    Bacterial type IV pili (T4P) are long, flexible surface filaments that consist of helical polymers of mostly pilin subunits. Cycles of polymerization, attachment, and depolymerization mediate several pilus-dependent bacterial behaviors, including twitching motility, surface adhesion, pathogenicity, natural transformation, escape from immune system defense mechanisms, and biofilm formation. The Xanthomonas citri subsp. citri strain 306 genome codes for a large set of genes involved in T4P biogenesis and regulation and includes several pilin homologs. We show that X. citri subsp. citri can exhibit twitching motility in a manner similar to that observed in other bacteria such as Pseudomonas aeruginosa and Xylella fastidiosa and that this motility is abolished in Xanthomonas citri subsp. citri knockout strains in the genes coding for the major pilin subunit PilAXAC3241, the ATPases PilBXAC3239 and PilTXAC2924, and the T4P biogenesis regulators PilZXAC1133 and FimXXAC2398. Microscopy analyses were performed to compare patterns of bacterial migration in the wild-type and knockout strains and we observed that the formation of mushroom-like structures in X. citri subsp. citri biofilm requires a functional T4P. Finally, infection of X. citri subsp. citri cells by the bacteriophage (ΦXacm4-11 is T4P dependent. The results of this study improve our understanding of how T4P influence Xanthomonas motility, biofilm formation, and susceptibility to phage infection. PMID:25180689

  6. The relationship between the intracellular Ca2+ transient and the isometric twitch force in frog muscle fibres.

    PubMed

    Sun, Y B; Lou, F; Edman, K A

    1996-09-01

    The calcium-sensitive fluorescent indicator fluo-3 was used to monitor the intracellular free calcium concentration ([Ca2+]i) during isometric twitches in twenty-nine single muscle fibres from the anterior tibialis muscle of Rana temporaria (sarcomere length, 2.2 microns; 2-4 degrees C). The transient change in [Ca2+]i in response to a single stimulus was very brief. The time to peak and the duration of the Ca2+ signal, measured at 50% of the peak amplitude, were 8.3 +/- 0.2 and 22.1 +/- 1.4 ms (mean +/- S.E.M., n = 29), respectively. The mean peak amplitude of the Ca2+ transient was 3.2 +/- 0.1 microM, ranging from 2.46 to 3.92 microM among the different fibres. The isometric force started to rise 2.5 ms before [Ca2+]i reached its maximum value. When peak twitch force was attained, [Ca2+]i had already declined to approximately 10% of its maximum value. The peak force produced during a twitch was closely related to the decay phase of the Ca2+ transient, a slower decay of [Ca2+]i being associated with a greater amplitude of the twitch. The amplitude and duration of the Ca2+ transient varied in a systematic way relative to one another in different fibres, in that a greater amplitude was associated with a more rapid decay of the Ca2+ transient. NO3- and Zn2+ added to the external medium greatly enhanced the peak twitch force without markedly affecting the amplitude of the Ca2+ transient. However, both agents delayed the decay of [Ca2+]i. It is concluded that the decay phase of the Ca2+ transient is a more important determinant of the mechanical response during an isometric twitch than is the peak amplitude of the transient. PMID:8889472

  7. Opiate-like inhibitory effect of trimebutine on the twitch response of the isolated guinea pig ileum.

    PubMed

    Yamasato, T; Takaki, M; Nakayama, S

    1987-02-01

    Trimebutine at low concentrations (6 X 10(-9)-1.4 X 10(-8) M) slightly enhanced the twitch response of isolated guinea pig ileum induced by transmural stimulation. At high concentrations (2 X 10(-8)-2 X 10(-7) M), however, it inhibited the twitch response in a dose dependent manner. This inhibitory effect of trimebutine was reversed by naloxone (8.1 X 10(-9) M). These results suggest that trimebutine has an opiate-like action on the myenteric plexus. PMID:3565073

  8. Head circumference

    MedlinePlus

    ... a child's head circumference Normal ranges for a child's sex and age (weeks, months), based on values that experts have obtained for normal growth rates of infants' and children's heads Measurement of the head circumference is an ...

  9. Head Lice

    MedlinePlus

    Head lice are parasitic wingless insects. They live on people's heads and feed on their blood. An adult louse ... Children ages 3-11 and their families get head lice most often. Personal hygiene has nothing to ...

  10. Head Injuries

    MedlinePlus

    ... of head injuries include bicycle or motorcycle wrecks, sports injuries, falls from windows (especially among children who live ... to watch for? When can I start playing sports again after a head injury? How can brain damage from a head injury ...

  11. Head Lice

    MedlinePlus

    Head lice are parasitic wingless insects. They live on people's heads and feed on their blood. An adult ... Children ages 3-11 and their families get head lice most often. Personal hygiene has nothing to do ...

  12. Cytosolic calcium and myofilaments in single rat cardiac myocytes achieve a dynamic equilibrium during twitch relaxation.

    PubMed Central

    Spurgeon, H A; duBell, W H; Stern, M D; Sollott, S J; Ziman, B D; Silverman, H S; Capogrossi, M C; Talo, A; Lakatta, E G

    1992-01-01

    1. Single isolated rat cardiac myocytes were loaded with either the pentapotassium salt form or the acetoxymethyl ester (AM) form of the calcium-sensitive fluorescent probe, Indo-1. The relationship of the Indo-1 fluorescence transient, an index of the change in cytosolic calcium [Ca2+]i concentration, to the simultaneously measured cell length during the electrically stimulated twitch originating from slack length at 23 degrees C was evaluated. It was demonstrated that even if the Ca2+ dissociation rate from Indo-1 was assumed to be as slow as 10 s-1, the descending limb ('relaxation phase') of the Indo-1 fluorescence transient induced by excitation under these conditions is in equilibrium with the [Ca2+]i transient. Additionally, the extent of Indo-1 loading employed did not substantially alter the twitch characteristics. 2. A unique relationship between the fluorescence transient and cell length was observed during relaxation of contractions that varied in amplitude. This was manifest as a common trajectory in the cell length vs. [Ca2+]i phase-plane diagrams beginning at the time of cell relengthening. The common trajectory could also be demonstrated in Indo-1 AM-loaded cells. The Indo-1 fluorescence-length relation defined by this common trajectory is steeper than that described by the relation of peak contraction amplitude and peak fluorescence during the twitch contractions. 3. The trajectory of the [Ca2+]i-length relation elicited via an abrupt, rapid, brief (200 ms) pulse of caffeine directly onto the cell surface or by 'tetanization' of cells in the presence of ryanodine is identical to the common [Ca2+]i-length trajectory formed by electrically stimulated contractions of different magnitudes. As the [Ca2+]i and length transients induced by caffeine application or during tetanization in the presence of ryanodine develop with a much slower time course than those elicited by electrical stimulation, the common trajectory is not fortuitous, i.e. it cannot be

  13. Contractile properties of rat fast-twitch skeletal muscle during reinnervation - Effects of testosterone and castration

    NASA Technical Reports Server (NTRS)

    Yeagle, S. P.; Mayer, R. F.; Max, S. R.

    1983-01-01

    The peroneal nerve of subject rats were crushed 1 cm from the muscle in order to examine the isometric contractile properties of skeletal muscle in the recovery sequency during reinnervation of normal, castrated, and testosterone-treated rats. The particular muscle studied was the extensor digitorum longus, with functional reinnervation first observed 8-9 days after nerve crush. No evidence was found that either castration or testosterone injections altered the process of reinnervation after the nerve crush, with the conclusion being valid at the 0.05 p level. The most reliable index of reinnervation was found to be the twitch:tetanus ratio, a factor of use in future studies of the reinnervation of skeletal muscle.

  14. SPASM and Twitch Domains in S-Adenosylmethionine (SAM) Radical Enzymes*

    PubMed Central

    Grell, Tsehai A. J.; Goldman, Peter J.; Drennan, Catherine L.

    2015-01-01

    S-Adenosylmethionine (SAM, also known as AdoMet) radical enzymes use SAM and a [4Fe-4S] cluster to catalyze a diverse array of reactions. They adopt a partial triose-phosphate isomerase (TIM) barrel fold with N- and C-terminal extensions that tailor the structure of the enzyme to its specific function. One extension, termed a SPASM domain, binds two auxiliary [4Fe-4S] clusters and is present within peptide-modifying enzymes. The first structure of a SPASM-containing enzyme, anaerobic sulfatase-maturating enzyme (anSME), revealed unexpected similarities to two non-SPASM proteins, butirosin biosynthetic enzyme 2-deoxy-scyllo-inosamine dehydrogenase (BtrN) and molybdenum cofactor biosynthetic enzyme (MoaA). The latter two enzymes bind one auxiliary cluster and exhibit a partial SPASM motif, coined a Twitch domain. Here we review the structure and function of auxiliary cluster domains within the SAM radical enzyme superfamily. PMID:25477505

  15. An Active Learning Mammalian Skeletal Muscle Lab Demonstrating Contractile and Kinetic Properties of Fast- and Slow-Twitch Muscle

    ERIC Educational Resources Information Center

    Head, S. I.; Arber, M. B.

    2013-01-01

    The fact that humans possess fast and slow-twitch muscle in the ratio of approximately 50% has profound implications for designing exercise training strategies for power and endurance activities. With the growth of exercise and sport science courses, we have seen the need to develop an undergraduate student laboratory that demonstrates the basic…

  16. Visualization of twitching motility and characterization of the role of the PilG in Xylella fastidiosa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Type IV pili of Xylella fastidiosa are regulated by pilG, a chemotaxis regulator in the Pil-Chp operon involving signal transduction pathways. To elucidate the role of pilG in twitching motility and pathogenicity of X. fastidiosa, the phenotypes of wild type, a pilG-deficient mutant (Xf'pilG), and a...

  17. Calcium-Enhanced Twitching Motility in Xylella fastidiosa Is Linked to a Single PilY1 Homolog.

    PubMed

    Cruz, Luisa F; Parker, Jennifer K; Cobine, Paul A; De La Fuente, Leonardo

    2014-12-01

    The plant-pathogenic bacterium Xylella fastidiosa is restricted to the xylem vessel environment, where mineral nutrients are transported through the plant host; therefore, changes in the concentrations of these elements likely impact the growth and virulence of this bacterium. Twitching motility, dependent on type IV pili (TFP), is required for movement against the transpiration stream that results in basipetal colonization. We previously demonstrated that calcium (Ca) increases the motility of X. fastidiosa, although the mechanism was unknown. PilY1 is a TFP structural protein recently shown to bind Ca and to regulate twitching and adhesion in bacterial pathogens of humans. Sequence analysis identified three pilY1 homologs in X. fastidiosa (PD0023, PD0502, and PD1611), one of which (PD1611) contains a Ca-binding motif. Separate deletions of PD0023 and PD1611 resulted in mutants that still showed twitching motility and were not impaired in attachment or biofilm formation. However, the response of increased twitching at higher Ca concentrations was lost in the pilY1-1611 mutant. Ca does not modulate the expression of any of the X. fastidiosa PilY1 homologs, although it increases the expression of the retraction ATPase pilT during active movement. The evidence presented here suggests functional differences between the PilY1 homologs, which may provide X. fastidiosa with an adaptive advantage in environments with high Ca concentrations, such as xylem sap. PMID:25217013

  18. Can fast-twitch muscle fibres be selectively recruited during lengthening contractions? Review and applications to sport movements.

    PubMed

    Chalmers, Gordon R

    2008-01-01

    Literature examining the recruitment order of motor units during lengthening (eccentric) contractions was reviewed to determine if fast-twitch motor units can be active while lower threshold slow-twitch motor units are not active. Studies utilizing surface electromyogram (EMG) amplitude, single motor unit activity, spike amplitude-frequency analyses, EMG power spectrum, mechanomyographic, and phosphocreatine-to-creatine ratio (PCr/Cr) techniques were reviewed. Only single motor unit and PCr/Cr data were found to be suitable to address the goals of this review. Nine of ten single motor unit studies, examining joint movement velocities up to 225 degrees/s and forces up to 53% of a maximum voluntary contraction, found that the size principle of motor unit recruitment applied during lengthening contractions. Deviation from the size principle was demonstrated by one study examining movements within a small range of low velocities and modest forces, although other studies examining similar low forces and lengthening velocities reported size-ordered recruitment. The PCr/Cr data demonstrated the activation of all fibre types in lengthening maximal contractions. Most evidence indicates that for lengthening contractions of a wide range of efforts and speeds, fast-twitch muscle fibres cannot be selectively recruited without activity of the slow-twitch fibres of the same muscle. PMID:18341141

  19. Calcium-Enhanced Twitching Motility in Xylella fastidiosa Is Linked to a Single PilY1 Homolog

    PubMed Central

    Cruz, Luisa F.; Parker, Jennifer K.; Cobine, Paul A.

    2014-01-01

    The plant-pathogenic bacterium Xylella fastidiosa is restricted to the xylem vessel environment, where mineral nutrients are transported through the plant host; therefore, changes in the concentrations of these elements likely impact the growth and virulence of this bacterium. Twitching motility, dependent on type IV pili (TFP), is required for movement against the transpiration stream that results in basipetal colonization. We previously demonstrated that calcium (Ca) increases the motility of X. fastidiosa, although the mechanism was unknown. PilY1 is a TFP structural protein recently shown to bind Ca and to regulate twitching and adhesion in bacterial pathogens of humans. Sequence analysis identified three pilY1 homologs in X. fastidiosa (PD0023, PD0502, and PD1611), one of which (PD1611) contains a Ca-binding motif. Separate deletions of PD0023 and PD1611 resulted in mutants that still showed twitching motility and were not impaired in attachment or biofilm formation. However, the response of increased twitching at higher Ca concentrations was lost in the pilY1-1611 mutant. Ca does not modulate the expression of any of the X. fastidiosa PilY1 homologs, although it increases the expression of the retraction ATPase pilT during active movement. The evidence presented here suggests functional differences between the PilY1 homologs, which may provide X. fastidiosa with an adaptive advantage in environments with high Ca concentrations, such as xylem sap. PMID:25217013

  20. Calcium-activated force responses in fast- and slow-twitch skinned muscle fibres of the rat at different temperatures.

    PubMed Central

    Stephenson, D G; Williams, D A

    1981-01-01

    1. Force responses from mechanically skinned fibres of rat skeletal muscles (extensor digitorum longus and soleus) were measured at different temperatures in the range 3-35 degrees C following sudden changes in Ca2+ concentration in the preparations. 2. At all temperatures there were characteristic differences between the slow- and fast-twitch muscle fibres with respect to the relative steady-state force-[Ca2+] relation: such as a lower [Ca2+] threshold for activation and a less steep force-pCa curve in slow-twitch muscle fibres. 3. At 3-5 degrees C the force changes in both types of muscle fibres lagged considerably behind the estimated changes in [Ca2+] within the preparations and this enabled us to perform a comparative analysis of the Ca2+ kinetics in the process of force development in both muscle fibre types. This analysis suggest that two and six Ca2+ ions are involved in the regulatory unit for contraction of slow- and fast-twitch muscle fibres respectively. 4. The rate of relaxation following a sudden decrease in [Ca2+] was much lower in the slow-twitch than in the fast-twitch muscle at 5 degrees C, suggesting that properties of the contractile apparatus could play an essential role in determining the rate of relaxation in vivo. 5. There was substantial variation in Ca2+ sensitivity between muscle fibres of the same type from different animals at each temperature. However the steepness of the force-[Ca2+] relation was essentially the same for all fibres of the same type. 6. A change in temperature from 5 to 25 degrees C had a statistically significant effect on the sensitivity of the fast-twitch muscle fibres, rendering them less sensitive to Ca2+ by a factor of 2. However a further increase in temperature from 25 to 35 degrees C did not have any statistically significant effect on the force-[Ca2+] relation in fast-twitch muscle fibres. 7. The effect of temperature on the Ca2+ sensitivity of slow-twitch muscle fibres was not statistically significant

  1. 5-HT2 receptor affinity, docking studies and pharmacological evaluation of a series of 1,3-disubstituted thiourea derivatives.

    PubMed

    Bielenica, Anna; Kędzierska, Ewa; Koliński, Michał; Kmiecik, Sebastian; Koliński, Andrzej; Fiorino, Ferdinando; Severino, Beatrice; Magli, Elisa; Corvino, Angela; Rossi, Ilaria; Massarelli, Paola; Kozioł, Anna E; Sawczenko, Aleksandra; Struga, Marta

    2016-06-30

    A series of 10 thiourea derivatives have been synthesized by the reaction of aromatic amine with a substituted aryl (compounds 1-3, 6-8) and alkylphenyl (4, 5, 9, 10) isothiocyanates. Their in vitro and in vivo pharmacological properties were studied. Among the evaluated compounds, two displayed very high affinity for the 5-HT2A receptor (1-0.043 nM and 5-0.6 nM), being selective over the 5-HT2C receptor. Derivatives 3, 5, 9, 10 by 70-89% diminished L-5-HTP-induced head twitch episodes. Compounds 1 and 5 as the 5-HT2A receptor antagonists produced a dose-dependent decrease in the number of DOI-elicited HTR. Compounds 1-5 strongly reduced amphetamine-evoked hyperactivity in rodents. In another test, 1 and 2 caused hyperthermia in mice, whereas 9 and 10 led to hypothermia. Antinociceptive and anticonvulsant properties of selected derivatives were demonstrated. Molecular docking studies using a homology model of 5-HT2A revealed a significant role of hydrogen bonds between both thiourea NH groups and Asp155/Tyr370 residues, as well as π-π interaction with Phe339. PMID:27061981

  2. Head Injuries

    MedlinePlus

    ... injuries internal head injuries, which may involve the skull, the blood vessels within the skull, or the brain Fortunately, most childhood falls or ... knock the brain into the side of the skull or tear blood vessels. Some internal head injuries ...

  3. Head Lice

    MedlinePlus

    ... or prescription products. Over-the-counter shampoos and lotions containing pyrethrin (one brand name: Rid) or permethrin ( ... commonly used to treat head lice. Shampoos and lotions that kill head lice contain pesticides and other ...

  4. Head MRI

    MedlinePlus

    ... the head; MRI - cranial; NMR - cranial; Cranial MRI; Brain MRI; MRI - brain; MRI - head ... tell your health care provider if you have: Brain aneurysm clips Certain types of artificial heart valves ...

  5. Head lice.

    PubMed

    Devore, Cynthia D; Schutze, Gordon E

    2015-05-01

    Head lice infestation is associated with limited morbidity but causes a high level of anxiety among parents of school-aged children. Since the 2010 clinical report on head lice was published by the American Academy of Pediatrics, newer medications have been approved for the treatment of head lice. This revised clinical report clarifies current diagnosis and treatment protocols and provides guidance for the management of children with head lice in the school setting. PMID:25917986

  6. Persistence of local twitch response with loss of conduction to and from the spinal cord.

    PubMed

    Hong, C Z

    1994-01-01

    A local twitch response (LTR) is a brisk contraction of a taut band of skeletal muscle fibers elicited by snapping palpation of a trigger point (TrP) in that band. The LTR is a clinically valuable objective sign that confirms the presence of a myofascial TrP. A transient burst of electromyographic (EMG) activity can be recorded from taut band fibers when an LTR is elicited by snapping palpation of TrP. A previous study of the human extensor digitorum muscle during ischemia suggested that both central and local pathways can be involved in the propagation of LTRs. In this study, EMG activity of LTRs in the third finger extensor muscle were recorded bilaterally in a patient with a unilateral brachial plexus lesion. This patient had complete loss of nerve conduction involving the posterior cord of the right brachial plexus as confirmed by EMG and nerve conduction studies and by neurological examination at 6 months after injury. EMG activity (measured as discharge duration and maximal amplitude) on the paralyzed side was significantly reduced (p < 0.01) as compared with the unaffected side, but had not disappeared. Three more studies were done at 7, 8, and 17 months after injury when the motor and sensory functions were recovered progressively. The EMG activity of LTRs recovered on the paralyzed side in parallel with the motor and sensory recovery. These findings indicate that the transmission of LTR depends mainly on the central nervous system with a possible minor degree of local transmission. PMID:8291955

  7. Histone deacetylase degradation and MEF2 activation promote the formation of slow-twitch myofibers.

    PubMed

    Potthoff, Matthew J; Wu, Hai; Arnold, Michael A; Shelton, John M; Backs, Johannes; McAnally, John; Richardson, James A; Bassel-Duby, Rhonda; Olson, Eric N

    2007-09-01

    Skeletal muscle is composed of heterogeneous myofibers with distinctive rates of contraction, metabolic properties, and susceptibility to fatigue. We show that class II histone deacetylase (HDAC) proteins, which function as transcriptional repressors of the myocyte enhancer factor 2 (MEF2) transcription factor, fail to accumulate in the soleus, a slow muscle, compared with fast muscles (e.g., white vastus lateralis). Accordingly, pharmacological blockade of proteasome function specifically increases expression of class II HDAC proteins in the soleus in vivo. Using gain- and loss-of-function approaches in mice, we discovered that class II HDAC proteins suppress the formation of slow twitch, oxidative myofibers through the repression of MEF2 activity. Conversely, expression of a hyperactive form of MEF2 in skeletal muscle of transgenic mice promotes the formation of slow fibers and enhances running endurance, enabling mice to run almost twice the distance of WT littermates. Thus, the selective degradation of class II HDACs in slow skeletal muscle provides a mechanism for enhancing physical performance and resistance to fatigue by augmenting the transcriptional activity of MEF2. These findings provide what we believe are new insights into the molecular basis of skeletal muscle function and have important implications for possible therapeutic interventions into muscular diseases. PMID:17786239

  8. Histone deacetylase degradation andMEF2 activation promote the formation of slow-twitch myofibers

    PubMed Central

    Potthoff, Matthew J.; Wu, Hai; Arnold, Michael A.; Shelton, John M.; Backs, Johannes; McAnally, John; Richardson, James A.; Bassel-Duby, Rhonda; Olson, Eric N.

    2007-01-01

    Skeletal muscle is composed of heterogeneous myofibers with distinctive rates of contraction, metabolic properties, and susceptibility to fatigue. We show that class II histone deacetylase (HDAC) proteins, which function as transcriptional repressors of the myocyte enhancer factor 2 (MEF2) transcription factor, fail to accumulate in the soleus, a slow muscle, compared with fast muscles (e.g., white vastus lateralis). Accordingly, pharmacological blockade of proteasome function specifically increases expression of class II HDAC proteins in the soleus in vivo. Using gain- and loss-of-function approaches in mice, we discovered that class II HDAC proteins suppress the formation of slow twitch, oxidative myofibers through the repression of MEF2 activity. Conversely, expression of a hyperactive form of MEF2 in skeletal muscle of transgenic mice promotes the formation of slow fibers and enhances running endurance, enabling mice to run almost twice the distance of WT littermates. Thus, the selective degradation of class II HDACs in slow skeletal muscle provides a mechanism for enhancing physical performance and resistance to fatigue by augmenting the transcriptional activity of MEF2. These findings provide what we believe are new insights into the molecular basis of skeletal muscle function and have important implications for possible therapeutic interventions into muscular diseases. PMID:17786239

  9. Estimating Isometric Tension of Finger Muscle Using Needle EMG Signals and the Twitch Contraction Model

    NASA Astrophysics Data System (ADS)

    Tachibana, Hideyuki; Suzuki, Takafumi; Mabuchi, Kunihiko

    We address an estimation method of isometric muscle tension of fingers, as fundamental research for a neural signal-based prosthesis of fingers. We utilize needle electromyogram (EMG) signals, which have approximately equivalent information to peripheral neural signals. The estimating algorithm comprised two convolution operations. The first convolution is between normal distribution and a spike array, which is detected by needle EMG signals. The convolution estimates the probability density of spike-invoking time in the muscle. In this convolution, we hypothesize that each motor unit in a muscle activates spikes independently based on a same probability density function. The second convolution is between the result of the previous convolution and isometric twitch, viz., the impulse response of the motor unit. The result of the calculation is the sum of all estimated tensions of whole muscle fibers, i.e., muscle tension. We confirmed that there is good correlation between the estimated tension of the muscle and the actual tension, with >0.9 correlation coefficients at 59%, and >0.8 at 89% of all trials.

  10. Effect of malnutrition on aerobic and anaerobic performance of fast- and slow-twitch muscles of rats.

    PubMed

    Nishio, M L; Jeejeebhoy, K N

    1992-01-01

    The effect of malnutrition on the functional properties of fast- and slow-twitch muscles from rats was studied using aerobic and anaerobic preparations. A 2-day fast and hypocaloric feeding to a weight loss of 25% were used as models of malnutrition. Soleus (slow-twitch) and extensor digitorum longus (EDL) (fast-twitch) muscles were studied using an in situ preparation with the blood supply intact and an in vitro preparation to which cyanide had been added to render the muscles anaerobic. We found that a 2-day fast had little effect on the function of muscles stimulated in situ, whereas anaerobic stimulation produced a decrease in force per gram of muscle weight in the soleus, but not in the EDL, compared with control values. Hypocaloric feeding resulted in a slowed relaxation rate, an increased Fs/Fmax ratio, and an upward shift of the force-frequency curve relative to controls when studied in situ. Under anaerobic conditions, soleus muscles from hypocaloric rats continued to show a slow relaxation rate and demonstrated a loss of force per gram of muscle weight compared with controls, particularly at low stimulation frequencies. EDL muscles from hypocaloric rats had an increased relaxation rate and were able to maintain force with anaerobic stimulation. Soleus and EDL muscles from the fasted and hypocaloric groups had lower activities of phosphofructokinase. We conclude that slow-twitch muscles from malnourished rats are at a disadvantage when required to function under anaerobic conditions. These findings suggest that muscle performance may be impaired in malnourished patients subjected to hypoxia. PMID:1386893

  11. Adaptive responses of GLUT-4 and citrate synthase in fast-twitch muscle of voluntary running rats

    NASA Technical Reports Server (NTRS)

    Henriksen, E. J.; Halseth, A. E.

    1995-01-01

    Glucose transporter (GLUT-4) protein, hexokinase, and citrate synthase (proteins involved in oxidative energy production from blood glucose catabolism) increase in response to chronically elevated neuromuscular activity. It is currently unclear whether these proteins increase in a coordinated manner in response to this stimulus. Therefore, voluntary wheel running (WR) was used to chronically overload the fast-twitch rat plantaris muscle and the myocardium, and the early time courses of adaptative responses of GLUT-4 protein and the activities of hexokinase and citrate synthase were characterized and compared. Plantaris hexokinase activity increased 51% after just 1 wk of WR, whereas GLUT-4 and citrate synthase were increased by 51 and 40%, respectively, only after 2 wk of WR. All three variables remained comparably elevated (+50-64%) through 4 wk of WR. Despite the overload of the myocardium with this protocol, no substantial elevations in these variables were observed. These findings are consistent with a coordinated upregulation of GLUT-4 and citrate synthase in the fast-twitch plantaris, but not in the myocardium, in response to this increased neuromuscular activity. Regulation of hexokinase in fast-twitch muscle appears to be uncoupled from regulation of GLUT-4 and citrate synthase, as increases in the former are detectable well before increases in the latter.

  12. Involvement of norepinephrine and serotonin system in antidepressant-like effects of oleoylethanolamide in the mice models of behavior despair.

    PubMed

    Yu, Hai-Ling; Sun, Lian-Ping; Li, Miao-Miao; Quan, Zhe-Shan

    2015-04-23

    Oleoylethanolamide (OEA) is an endocannabinoid analogy that belongs to a family of endogenous acylethanolamides. Increasing evidence suggests that OEA may act as an endogenous neuroprotective factor and participate in the control of mental disorder-related behaviors. In the present study, we investigated the antidepressant- like potential of OEA in mice in comparison with clomipramine (Cp). 50 mice were randomly divided into 5 groups, and treated with a vehicle (0.3% methyl cellulose, 20 mL/kg, p.o.), OEA (2.5, 5-10mg/kg, p.o.), or Cp (10mg/kg, p.o.) for 7 days. The immobility was used to evaluate depressive-like behaviors in tail suspension test (TST) and forced swimming test (FST). ELISA detected changes in cerebral noradrenaline (NE) and serotonin (5-HT) levels. Likewise, in the drug-induced model of depression, OEA was given once daily at 10mg/kg (p.o.) for 7 consecutive days. Then, the mice received reserpine (4 mg/kg, i.p.) and the rectal temperature was measured at different time points. Consequently, head twitch behavior induced by intraperitoneal injection of 5-hydroxy-tryptophan (5-HTP; 300 mg/kg) were determined. The experimental data showed that OEA (2.5-10mg/kg) treatment significantly decreased the immobility as compared to the control group, and OEA (10mg/kg) treatment significantly increased 5-HTP-induced head twitch behavior and reversed reserpine-induced hypothermia and increased cerebral levels of NE and 5-HT. Thus, the antidepressant effects of OEA may be related to regulating central monoamine neurotransmitters. PMID:25778418

  13. Unchanged content of oxidative enzymes in fast-twitch muscle fibers and kinetics after intensified training in trained cyclists

    PubMed Central

    Christensen, Peter M; Gunnarsson, Thomas P; Thomassen, Martin; Wilkerson, Daryl P; Nielsen, Jens Jung; Bangsbo, Jens

    2015-01-01

    The present study examined if high intensity training (HIT) could increase the expression of oxidative enzymes in fast-twitch muscle fibers causing a faster oxygen uptake () response during intense (INT), but not moderate (MOD), exercise and reduce the slow component and muscle metabolic perturbation during INT. Pulmonary kinetics was determined in eight trained male cyclists (-max: 59 ± 4 (means ± SD) mL min−1 kg−1) during MOD (205 ± 12 W ∼65% -max) and INT (286 ± 17 W ∼85% -max) exercise before and after a 7-week HIT period (30-sec sprints and 4-min intervals) with a 50% reduction in volume. Both before and after HIT the content in fast-twitch fibers of CS (P < 0.05) and COX-4 (P < 0.01) was lower, whereas PFK was higher (P < 0.001) than in slow-twitch fibers. Content of CS, COX-4, and PFK in homogenate and fast-twitch fibers was unchanged with HIT. Maximal activity (μmol g DW−1 min−1) of CS (56 ± 8 post-HIT vs. 59 ± 10 pre-HIT), HAD (27 ± 6 vs. 29 ± 3) and PFK (340 ± 69 vs. 318 ± 105) and the capillary to fiber ratio (2.30 ± 0.16 vs. 2.38 ± 0.20) was unaltered following HIT. kinetics was unchanged with HIT and the speed of the primary response did not differ between MOD and INT. Muscle creatine phosphate was lower (42 ± 15 vs. 66 ± 17 mmol kg DW−1) and muscle lactate was higher (40 ± 18 vs. 14 ± 5 mmol kg DW−1) at 6 min of INT (P < 0.05) after compared to before HIT. A period of intensified training with a volume reduction did not increase the content of oxidative enzymes in fast-twitch fibers, and did not change kinetics. PMID:26152692

  14. External potassium and action potential propagation in rat fast and slow twitch muscles.

    PubMed

    Kössler, F; Lange, F; Caffier, G; Küchler, G

    1991-10-01

    The role of extracellular K+ concentration in the propagation velocity of action potential was tested in isolated rat skeletal muscles. Different K+ concentrations were produced by KCl additions to extracellular solution. Action potentials were measured extracellularly by means of two annular platinum electrodes. Fibre bundles of m. soleus (SOL), m. extensor digitorum longus (EDL), red (SMR) and white (SMW) part of m. sternomastoideus were maximum stimulated. The conduction velocity (c.v.) was calculated from the distance between the electrodes and the time delay of the potentials measured at 22 degrees C. In Tyrode solution containing 5 mmol/l K+, the c.v. was close to 1 m.s-1. Bundles of the fast muscle type seemed to have a somewhat higher c.v. The differences observed in these studies were not significant. At higher temperatures, the c.v. increased (Q10 of approx. 2) and a dissociation between SMR and SMW muscles appeared. An elevation of K+ concentration to 10 mmol/l induced a drop of the c.v. by approx. 25% and 15% in EDL and SOL muscles, respectively. After return to normal solution, the recovery was not complete within 30 min. In K+ free solution the c.v. of EDL and SM muscles rose by a factor of 1.5, but less in SOL muscles. The weaker response of SOL to K+ modification was related to the higher resistance of this muscle to fatigue. This suggestion was supported by experiments on fatigued fibre bundles. Immediately after a tetanic stimulation producing fatigue, the c.v. of EDL and SOL muscles dropped similarly as in 10 mmol/l K+; again, the drop was less for SOL muscles. Adrenaline (0.5-10.0 mumol/l) enhanced both the c.v. and the twitch amplitude. The results support the suggestion that extracellular K+ accumulation during activity is an essential factor of muscle fatigue. PMID:1816028

  15. Involvement of AMPK in regulating slow-twitch muscle atrophy during hindlimb unloading in mice.

    PubMed

    Egawa, Tatsuro; Goto, Ayumi; Ohno, Yoshitaka; Yokoyama, Shingo; Ikuta, Akihiro; Suzuki, Miho; Sugiura, Takao; Ohira, Yoshinobu; Yoshioka, Toshitada; Hayashi, Tatsuya; Goto, Katsumasa

    2015-10-01

    AMPK is considered to have a role in regulating skeletal muscle mass. However, there are no studies investigating the function of AMPK in modulating skeletal muscle mass during atrophic conditions. In the present study, we investigated the difference in unloading-associated muscle atrophy and molecular functions in response to 2-wk hindlimb suspension between transgenic mice overexpressing the dominant-negative mutant of AMPK (AMPK-DN) and their wild-type (WT) littermates. Male WT (n = 24) and AMPK-DN (n = 24) mice were randomly divided into two groups: an untreated preexperimental control group (n = 12 in each group) and an unloading (n = 12 in each group) group. The relative soleus muscle weight and fiber cross-sectional area to body weight were decreased by ∼30% in WT mice by hindlimb unloading and by ∼20% in AMPK-DN mice. There were no changes in puromycin-labeled protein or Akt/70-kDa ribosomal S6 kinase signaling, the indicators of protein synthesis. The expressions of ubiquitinated proteins and muscle RING finger 1 mRNA and protein, markers of the ubiquitin-proteasome system, were increased by hindlimb unloading in WT mice but not in AMPK-DN mice. The expressions of molecules related to the protein degradation system, phosphorylated forkhead box class O3a, inhibitor of κBα, microRNA (miR)-1, and miR-23a, were decreased only in WT mice in response to hindlimb unloading, and 72-kDa heat shock protein expression was higher in AMPK-DN mice than in WT mice. These results imply that AMPK partially regulates unloading-induced atrophy of slow-twitch muscle possibly through modulation of the protein degradation system, especially the ubiquitin-proteasome system. PMID:26244519

  16. Calcium Increases Xylella fastidiosa Surface Attachment, Biofilm Formation, and Twitching Motility

    PubMed Central

    Cruz, Luisa F.; Cobine, Paul A.

    2012-01-01

    Xylella fastidiosa is a plant-pathogenic bacterium that forms biofilms inside xylem vessels, a process thought to be influenced by the chemical composition of xylem sap. In this work, the effect of calcium on the production of X. fastidiosa biofilm and movement was analyzed under in vitro conditions. After a dose-response study with 96-well plates using eight metals, the strongest increase of biofilm formation was observed when medium was supplemented with at least 1.0 mM CaCl2. The removal of Ca by extracellular (EGTA, 1.5 mM) and intracellular [1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid acetoxymethyl ester (BAPTA/AM), 75 μM] chelators reduced biofilm formation without compromising planktonic growth. The concentration of Ca influenced the force of adhesion to the substrate, biofilm thickness, cell-to-cell aggregation, and twitching motility, as shown by assays with microfluidic chambers and other assays. The effect of Ca on attachment was lost when cells were treated with tetracycline, suggesting that Ca has a metabolic or regulatory role in cell adhesion. A double mutant (fimA pilO) lacking type I and type IV pili did not improve biofilm formation or attachment when Ca was added to the medium, while single mutants of type I (fimA) or type IV (pilB) pili formed more biofilm under conditions of higher Ca concentrations. The concentration of Ca in the medium did not significantly influence the levels of exopolysaccharide produced. Our findings indicate that the role of Ca in biofilm formation may be related to the initial surface and cell-to-cell attachment and colonization stages of biofilm establishment, which rely on critical functions by fimbrial structures. PMID:22194297

  17. Head lice.

    PubMed

    Frankowski, Barbara L; Bocchini, Joseph A

    2010-08-01

    Head lice infestation is associated with limited morbidity but causes a high level of anxiety among parents of school-aged children. Since the 2002 clinical report on head lice was published by the American Academy of Pediatrics, patterns of resistance to products available over-the-counter and by prescription have changed, and additional mechanical means of removing head lice have been explored. This revised clinical report clarifies current diagnosis and treatment protocols and provides guidance for the management of children with head lice in the school setting. PMID:20660553

  18. Presence of calcium-binding motifs in PilY1 homologs correlates with Ca-mediated twitching motility and evolutionary history across diverse bacteria.

    PubMed

    Parker, Jennifer K; Cruz, Luisa F; Evans, Michael R; De La Fuente, Leonardo

    2015-02-01

    Twitching motility, involving type IV pili, is essential for host colonization and virulence of many pathogenic bacteria. Studies of PilY1, a tip-associated type IV pili protein, indicate that PilY1 functions as a switch between pilus extension and retraction, resulting in twitching motility. Recent work detected a calcium-binding motif in PilY1 of some animal bacterial pathogens and demonstrated that binding of calcium to PilY1 with this motif regulates twitching. Though studies of PilY1 in non-animal pathogens are limited, our group demonstrated that twitching motility in the plant pathogen Xylella fastidiosa, which contains three PilY1 homologs, is increased by calcium supplementation. A study was conducted to investigate the phylogenetic relationship between multiple PilY1 homologs, the presence of calcium-binding motifs therein, and calcium-mediated twitching motility across diverse bacteria. Strains analyzed contained one to three PilY1 homologs, but phylogenetic analyses indicated that PilY1 homologs containing the calcium-binding motif Dx[DN]xDGxxD are phylogenetically divergent from other PilY1 homologs. Plant-associated bacteria included in these analyses were then examined for a calcium-mediated twitching response. Results indicate that bacteria must have at least one PilY1 homolog containing the Dx[DN]xDGxxD motif to display a calcium-mediated increase in twitching motility, which likely reflects an adaption to environmental calcium concentrations. PMID:25688068

  19. Differential regulation of apoptosis in slow and fast twitch muscles of aged female F344BN rats

    SciTech Connect

    Rice, Kevin M.; Manne, Nandini D. P. K.; Gadde, Murali K.; Paturi, Satyanarayana; Arvapalli, Ravikumar; Blough, Eric

    2015-03-28

    Age-related muscle atrophy is characterized by decreases in muscle mass and is thought be mediated, at least in part, by increases in myocyte apoptosis. Recent data has demonstrated that the degree of muscle loss with aging may differ between males and females while other work has suggested that apoptosis as indicated by DNA fragmentation may be regulated differently in fast- and slow-twitch muscles. Herein, we investigate how aging affects the regulation of muscle apoptosis in the fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus muscles of young (6-month), aged (26-month), and very aged (30-month) female Fischer 344/NNiaHSD × Brown Norway/BiNia (F344BN) rats. Tissue sections were stained with hydroethidium for ROS and protein extract was subjected to immunoblotting for assessing apoptotic markers. Our data suggest that decreases in muscle mass were associated with increased DNA fragmentation (TUNEL positive) and increases in reactive oxygen species (ROS) as determined by hydroethidium staining in both the EDL and soleus. Similar to our previous work using aged male animals, we observed that the time course and magnitude of changes in Bax, Bcl-2, caspase-3, caspase-9, and cleavage of α-fodrin protein were regulated differently between muscles. As a result, These data suggest that aging in the female F344BN rat is associated with decreases in muscle mass, elevations in ROS level, increased muscle cell DNA fragmentation, and alterations in cell membrane integrity and that apoptotic mechanisms may differ between fiber types.

  20. Differential regulation of apoptosis in slow and fast twitch muscles of aged female F344BN rats

    DOE PAGESBeta

    Rice, Kevin M.; Manne, Nandini D. P. K.; Gadde, Murali K.; Paturi, Satyanarayana; Arvapalli, Ravikumar; Blough, Eric

    2015-03-28

    Age-related muscle atrophy is characterized by decreases in muscle mass and is thought be mediated, at least in part, by increases in myocyte apoptosis. Recent data has demonstrated that the degree of muscle loss with aging may differ between males and females while other work has suggested that apoptosis as indicated by DNA fragmentation may be regulated differently in fast- and slow-twitch muscles. Herein, we investigate how aging affects the regulation of muscle apoptosis in the fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus muscles of young (6-month), aged (26-month), and very aged (30-month) female Fischer 344/NNiaHSD × Brown Norway/BiNiamore » (F344BN) rats. Tissue sections were stained with hydroethidium for ROS and protein extract was subjected to immunoblotting for assessing apoptotic markers. Our data suggest that decreases in muscle mass were associated with increased DNA fragmentation (TUNEL positive) and increases in reactive oxygen species (ROS) as determined by hydroethidium staining in both the EDL and soleus. Similar to our previous work using aged male animals, we observed that the time course and magnitude of changes in Bax, Bcl-2, caspase-3, caspase-9, and cleavage of α-fodrin protein were regulated differently between muscles. As a result, These data suggest that aging in the female F344BN rat is associated with decreases in muscle mass, elevations in ROS level, increased muscle cell DNA fragmentation, and alterations in cell membrane integrity and that apoptotic mechanisms may differ between fiber types.« less

  1. Effects of thyroid hormone on fast- and slow-twitch skeletal muscles in young and old rats.

    PubMed Central

    Larsson, L; Li, X; Teresi, A; Salviati, G

    1994-01-01

    1. The effects of 4 weeks of thyroid hormone treatment on contractile, enzyme-histochemical and morphometric properties and on the myosin isoform composition were compared in the slow-twitch soleus and the fast-twitch extensor digitorum longus (EDL) muscle in young (3-6 months) and old (20-24 months) male rats. 2. In the soleus of untreated controls, contraction and half-relaxation times of the isometric twitch increased by 19-32% with age. The change in contractile properties was paralleled by an age-related increase in the proportions of type I fibres and type I myosin heavy chain (MHC) and slow myosin light chain (MLC) isoforms. 3. In the EDL of controls, contraction and half-relaxation times were significantly prolonged (21-38%) in the post-tetanus twitch in the old animals. No significant age-related changes were observed in enzyme-histochemical fibre-type proportions, although the number of fibres expressing both type IIA and IIB MHCs and of fibres expressing slow MLC isoforms was increased in the old animals. 4. Serum 3,5,3',5'-tetraiodothyronine (T4) levels were lower (34%) in the old animals, but the primary byproduct of T4, 3,5,3'-triiodothyronine (T3), did not differ between young and old animals. 5. The effects of 4 weeks of thyroid hormone treatment were highly muscle specific, and were more pronounced in soleus than in EDL, irrespective of animal age. In the soleus, this treatment shortened the contraction and half-relaxation times by 35-57% and decreased the number of type I fibres by 66-77% in both young and old animals. In EDL, thyroid hormone treatment significantly shortened the contraction time by 24%, but the change was restricted to the old animals. 6. In conclusion, the ability of skeletal muscle to respond to thyroid hormone treatment was not impaired in old age and the age-related changes in speed of contraction and enzyme-histochemical properties and myosin isoform compositions were diminished after thyroid hormone treatment in both the

  2. Head injury.

    PubMed

    Hureibi, K A; McLatchie, G R

    2010-05-01

    Head injury is one of the commonest injuries in sport. Most are mild but some can have serious outcomes. Sports medicine doctors should be able to recognise the clinical features and evaluate athletes with head injury. It is necessary during field assessment to recognise signs and symptoms that help in assessing the severity of injury and making a decision to return-to-play. Prevention of primary head injury should be the aim. This includes protective equipment like helmets and possible rule changes. PMID:20533694

  3. Task-dependent inhibition of slow-twitch soleus and excitation of fast-twitch gastrocnemius do not require high movement speed and velocity-dependent sensory feedback

    PubMed Central

    Mehta, Ricky; Prilutsky, Boris I.

    2014-01-01

    Although individual heads of triceps surae, soleus (SO) and medial gastrocnemius (MG) muscles, are often considered close functional synergists, previous studies have shown distinct activity patterns between them in some motor behaviors. The goal of this study was to test two hypotheses explaining inhibition of slow SO with respect to fast MG: (1) inhibition occurs at high movement velocities and mediated by velocity-dependent sensory feedback and (2) inhibition depends on the ankle-knee joint moment combination and does not require high movement velocities. The hypotheses were tested by comparing the SO EMG/MG EMG ratio during fast and slow motor behaviors (cat paw shake responses vs. back, straight leg load lifting in humans), which had the same ankle extension-knee flexion moment combination; and during fast and slow behaviors with the ankle extension-knee extension moment combination (human vertical jumping and stance phase of walking in cats and leg load lifting in humans). In addition, SO EMG/MG EMG ratio was determined during cat paw shake responses and walking before and after removal of stretch velocity-dependent sensory feedback by self-reinnervating SO and/or gastrocnemius. We found the ratio SO EMG/MG EMG below 1 (p < 0.05) during fast paw shake responses and slow back load lifting, requiring the ankle extension-knee flexion moment combination; whereas the ratio SO EMG/MG EMG was above 1 (p < 0.05) during fast vertical jumping and slow tasks of walking and leg load lifting, requiring ankle extension-knee extension moments. Removal of velocity-dependent sensory feedback did not affect the SO EMG/MG EMG ratio in cats. We concluded that the relative inhibition of SO does not require high muscle velocities, depends on ankle-knee moment combinations, and is mechanically advantageous for allowing a greater MG contribution to ankle extension and knee flexion moments. PMID:25389407

  4. Task-dependent inhibition of slow-twitch soleus and excitation of fast-twitch gastrocnemius do not require high movement speed and velocity-dependent sensory feedback.

    PubMed

    Mehta, Ricky; Prilutsky, Boris I

    2014-01-01

    Although individual heads of triceps surae, soleus (SO) and medial gastrocnemius (MG) muscles, are often considered close functional synergists, previous studies have shown distinct activity patterns between them in some motor behaviors. The goal of this study was to test two hypotheses explaining inhibition of slow SO with respect to fast MG: (1) inhibition occurs at high movement velocities and mediated by velocity-dependent sensory feedback and (2) inhibition depends on the ankle-knee joint moment combination and does not require high movement velocities. The hypotheses were tested by comparing the SO EMG/MG EMG ratio during fast and slow motor behaviors (cat paw shake responses vs. back, straight leg load lifting in humans), which had the same ankle extension-knee flexion moment combination; and during fast and slow behaviors with the ankle extension-knee extension moment combination (human vertical jumping and stance phase of walking in cats and leg load lifting in humans). In addition, SO EMG/MG EMG ratio was determined during cat paw shake responses and walking before and after removal of stretch velocity-dependent sensory feedback by self-reinnervating SO and/or gastrocnemius. We found the ratio SO EMG/MG EMG below 1 (p < 0.05) during fast paw shake responses and slow back load lifting, requiring the ankle extension-knee flexion moment combination; whereas the ratio SO EMG/MG EMG was above 1 (p < 0.05) during fast vertical jumping and slow tasks of walking and leg load lifting, requiring ankle extension-knee extension moments. Removal of velocity-dependent sensory feedback did not affect the SO EMG/MG EMG ratio in cats. We concluded that the relative inhibition of SO does not require high muscle velocities, depends on ankle-knee moment combinations, and is mechanically advantageous for allowing a greater MG contribution to ankle extension and knee flexion moments. PMID:25389407

  5. Head Injuries

    MedlinePlus

    ... before. Often, the injury is minor because your skull is hard and it protects your brain. But ... injuries can be more severe, such as a skull fracture, concussion, or traumatic brain injury. Head injuries ...

  6. Head Injuries

    MedlinePlus

    ... before. Usually, the injury is minor because your skull is hard and it protects your brain. But ... injuries can be more severe, such as a skull fracture, concussion, or traumatic brain injury. Head injuries ...

  7. Head Noises.

    ERIC Educational Resources Information Center

    Senior, Tom

    2000-01-01

    Explains how a toy called "Sound Bites" can be modified to demonstrate the transmission of sound waves. Students can hear music from the toy when they press it against any bone in their heads or shoulders. (WRM)

  8. The acute effect of neuromuscular activation in resistance exercise on human skeletal muscle with the interpolated twitch technique.

    PubMed

    Lee, Dae-Yeon; Yoon, Wan-Young

    2015-09-01

    [Purpose] The purpose of this study was to perform a quantitative assessment of neuromechanical adaptation in skeletal muscles and to propose the scientific underpinnings of the acute effects induced by resistance exercise. [Subjects] The subjects in this study were 11 healthy adult men in their 20s who had no orthopedic history at the time of the study. To examine any signs of resistance exercise-induced changes in the ankle plantar flexor, the subjects were directed to perform a standing barbell calf raise routine. [Methods] Subjects were to carry a load equal to their weights and to perform five sets of ten repetitions. The maximal voluntary isometric contraction torque, resting twitch torque, muscle inhibition, root mean square of muscular activation, contraction time, and half relaxation time were analyzed by synchronizing a dynamometer, an electrical stimulator, and an electromyography system. [Results] The maximal voluntary isometric contraction torque appeared to decline, but the change was not statistically significant. The decline of resting twitch torque, on the other hand, was found to be statistically significant. Muscle inhibition and root mean square of muscular activation were both reduced, but both changes were not statistically significant. Lastly, contraction time and half relaxation time both statistically decreased significantly after resistance exercise. [Conclusion] These results indicate that the acute effects of resistance exercise have a greater impact on the peripheral mechanical system itself, rather than on neurological factors, in terms of the generation of muscle force. PMID:26504316

  9. The group I pilin glycan affects type IVa pilus hydrophobicity and twitching motility in Pseudomonas aeruginosa 1244

    PubMed Central

    Allison, Tara M.; Conrad, Sean

    2015-01-01

    The group I pilin category is the most common type of type IVa pilus produced by Pseudomonas aeruginosa. The lateral surfaces of these pili are characterized by the presence of closely spaced, covalently attached O-antigen repeating units. The current work was conducted to investigate the pilin glycan's effect on pilus solubility and function. Culture supernatant fluids containing fully, partially and non-glycosylated P. aeruginosa group I pili were tested for solubility in the presence of ammonium sulfate. These results showed that while pili expressing three or four sugars were highly soluble under all conditions, those with fewer than three were insoluble under the lowest salt concentrations tested. A representative of the P. aeruginosa group II pili also showed low solubility when assayed under these same conditions. Reduced solubility suggested an increased pilus surface hydrophobicity, which was supported by protein modelling. While having no effect on the WT strain, an ionic strength found at many host infection sites inhibited surface and subsurface twitching motility of strain 1244G7, an isogenic mutant unable to glycosylate pilin. This effect was reversed by mutant complementation. Twitching motility of P. aeruginosa strain PA103, which produces group II pili, was also inhibited by ionic strengths which influenced the mutant 1244 strain. We suggest that the group I pilin glycan may, therefore, be beneficial to this organism specifically for optimal pilus functioning at the many host disease sites with ionic strengths comparable to those tested here. PMID:26297472

  10. Upregulation of MHC class I in transgenic mice results in reduced force-generating capacity in slow-twitch muscle.

    PubMed

    Salomonsson, Stina; Grundtman, Cecilia; Zhang, Shi-Jin; Lanner, Johanna T; Li, Charles; Katz, Abram; Wedderburn, Lucy R; Nagaraju, Kanneboyina; Lundberg, Ingrid E; Westerblad, Håkan

    2009-05-01

    Expression of major histocompatibility complex (MHC) class I in skeletal muscle fibers is an early and consistent finding in inflammatory myopathies. To test if MHC class I has a primary role in muscle impairment, we used transgenic mice with inducible overexpression of MHC class I in their skeletal muscle cells. Contractile function was studied in isolated extensor digitorum longus (EDL, fast-twitch) and soleus (slow-twitch) muscles. We found that EDL was smaller, whereas soleus muscle was slightly larger. Both muscles generated less absolute force in myopathic compared with control mice; however, when force was expressed per cross-sectional area, only soleus muscle generated less force. Inflammation was markedly increased, but no changes were found in the activities of key mitochondrial and glycogenolytic enzymes in myopathic mice. The induction of MHC class I results in muscle atrophy and an intrinsic decrease in force-generation capacity. These observations may have important implications for our understanding of the pathophysiological processes of muscle weakness seen in inflammatory myopathies. Muscle Nerve, 2008. PMID:19229963

  11. Effects of shakuyakukanzoto and its absorbed components on twitch contractions induced by physiological Ca2+ release in rat skeletal muscle.

    PubMed

    Kaifuchi, Noriko; Omiya, Yuji; Kushida, Hirotaka; Fukutake, Miwako; Nishimura, Hiroaki; Kase, Yoshio

    2015-07-01

    Shakuyakukanzoto (SKT) is a kampo medicine composed of equal proportions of Glycyrrhizae radix (G. radix) and Paeoniae radix (P. radix). A double-blind study reported that SKT significantly ameliorated painful muscle cramp in cirrhosis patients without the typical severe side effects of muscle weakness and central nervous system (CNS) depression. Previous basic studies reported that SKT and its active components induced relaxation by a direct action on skeletal muscle and that SKT did not depress CNS functions; however, why SKT has a lower incidence of muscle weakness remains unknown. In the present study, we investigated which components are absorbed into the blood of rats after a single oral administration of SKT to identify the active components of SKT. We also investigated the effects of SKT and its components on the twitch contraction induced by physiological Ca(2+) release. Our study demonstrated that SKT and five G. radix isolates, which are responsible for the antispasmodic effect of SKT, did not inhibit the twitch contraction in contrast to dantrolene sodium, a direct-acting peripheral muscle relaxant, indicating that the mechanisms of muscle contraction of SKT and dantrolene in skeletal muscle differ. These findings suggest that SKT does not reduce the contractile force in skeletal muscle under physiological conditions, i.e., SKT may have a low risk of causing muscle weakness in clinical use. Considering that most muscle relaxants and anticonvulsants cause various harmful side effects such as weakness and CNS depression, SKT appears to have a benign safety profile. PMID:25783410

  12. cAMP levels in fast- and slow-twitch skeletal muscle after an acute bout of aerobic exercise

    NASA Technical Reports Server (NTRS)

    Sheldon, A.; Booth, F. W.; Kirby, C. R.

    1993-01-01

    The present study examined whether exercise duration was associated with elevated and/or sustained elevations of postexercise adenosine 3',5'-cyclic monophosphate (cAMP) by measuring cAMP levels in skeletal muscle for up to 4 h after acute exercise bouts of durations that are known to either produce (60 min) or not produce (10 min) mitochondrial proliferation after chronic training. Treadmill-acclimatized, but untrained, rats were run at 22 m/min for 0 (control), 10, or 60 min and were killed at various postexercise (0, 0.5, 1, 2, and 4 h) time points. Fast-twitch white and red (quadriceps) and slow-twitch (soleus) muscles were quickly excised, frozen in liquid nitrogen, and assayed for cAMP with a commercial kit. Unexpectedly, cAMP contents in all three muscles were similar to control (nonexercise) at most (21 of 30) time points after a single 10- or 60-min run. Values at 9 of 30 time points were significantly different from control (P < 0.05); i.e., 3 time points were significantly higher than control and 6 were significantly less than control. These data suggest that the cAMP concentration of untrained skeletal muscle after a single bout of endurance-type exercise is not, by itself, associated with exercise duration.

  13. Glycolytic fast-twitch muscle fiber restoration counters adverse age-related changes in body composition and metabolism.

    PubMed

    Akasaki, Yuichi; Ouchi, Noriyuki; Izumiya, Yasuhiro; Bernardo, Barbara L; Lebrasseur, Nathan K; Walsh, Kenneth

    2014-02-01

    Aging is associated with the development of insulin resistance, increased adiposity, and accumulation of ectopic lipid deposits in tissues and organs. Starting in mid-life there is a progressive decline in lean muscle mass associated with the preferential loss of glycolytic, fast-twitch myofibers. However, it is not known to what extent muscle loss and metabolic dysfunction are causally related or whether they are independent epiphenomena of the aging process. Here, we utilized a skeletal-muscle-specific, conditional transgenic mouse expressing a constitutively active form of Akt1 to examine the consequences of glycolytic, fast-twitch muscle growth in young vs. middle-aged animals fed standard low-fat chow diets. Activation of the Akt1 transgene led to selective skeletal muscle hypertrophy, reversing the loss of lean muscle mass observed upon aging. The Akt1-mediated increase in muscle mass led to reductions in fat mass and hepatic steatosis in older animals, and corrected age-associated impairments in glucose metabolism. These results indicate that the loss of lean muscle mass is a significant contributor to the development of age-related metabolic dysfunction and that interventions that preserve or restore fast/glycolytic muscle may delay the onset of metabolic disease. PMID:24033924

  14. Comparative effect of low temperature on virulence and twitching motility of Ralstonia solanacearum strains present in Florida.

    PubMed

    Bocsanczy, Ana M; Achenbach, Ute C M; Mangravita-Novo, Arianna; Yuen, Jeanne M F; Norman, David J

    2012-02-01

    Ralstonia solanacearum causes bacterial wilt on a wide range of plant hosts. Most strains of R. solanacearum are nonpathogenic below 20°C; however, Race 3 Biovar 2 (R3B2) strains are classified as quarantine pathogens because of their ability to infect crops, cause disease, and survive in temperate climates. We have identified race 1 biovar 1 Phylotype IIB Sequevar 4 strains present in Florida which were able to infect and produce wilt symptoms on potato and tomato at 18°C. Moreover they infected tomato plants at rates similar to strains belonging to R3B2. We determined that strains naturally nonpathogenic at 18°C were able to multiply, move in planta, and cause partial wilt when inoculated directly into the stem, suggesting that low temperature affects virulence of strains differently at early stages of infection. Bacterial growth in vitro was delayed at low temperatures, however it was not attenuated. Twitching motility observed on growing colonies was attenuated in nonpathogenic strains at 18°C, while not affected in the cool virulent ones. Using pilQ as a marker to evaluate the relative expression of the twitching activity of R. solanacearum strains, we confirmed that cool virulent strains maintained a similar level of pilQ expression at both temperatures, while in nonpathogenic strains pilQ was downregulated at 18°C. PMID:21936660

  15. The acute effect of neuromuscular activation in resistance exercise on human skeletal muscle with the interpolated twitch technique

    PubMed Central

    Lee, Dae-Yeon; Yoon, Wan-Young

    2015-01-01

    [Purpose] The purpose of this study was to perform a quantitative assessment of neuromechanical adaptation in skeletal muscles and to propose the scientific underpinnings of the acute effects induced by resistance exercise. [Subjects] The subjects in this study were 11 healthy adult men in their 20s who had no orthopedic history at the time of the study. To examine any signs of resistance exercise-induced changes in the ankle plantar flexor, the subjects were directed to perform a standing barbell calf raise routine. [Methods] Subjects were to carry a load equal to their weights and to perform five sets of ten repetitions. The maximal voluntary isometric contraction torque, resting twitch torque, muscle inhibition, root mean square of muscular activation, contraction time, and half relaxation time were analyzed by synchronizing a dynamometer, an electrical stimulator, and an electromyography system. [Results] The maximal voluntary isometric contraction torque appeared to decline, but the change was not statistically significant. The decline of resting twitch torque, on the other hand, was found to be statistically significant. Muscle inhibition and root mean square of muscular activation were both reduced, but both changes were not statistically significant. Lastly, contraction time and half relaxation time both statistically decreased significantly after resistance exercise. [Conclusion] These results indicate that the acute effects of resistance exercise have a greater impact on the peripheral mechanical system itself, rather than on neurological factors, in terms of the generation of muscle force. PMID:26504316

  16. Slow- and fast-twitch hindlimb skeletal muscle phenotypes 12 wk after ⅚ nephrectomy in Wistar rats of both sexes.

    PubMed

    Acevedo, Luz M; Peralta-Ramírez, Alan; López, Ignacio; Chamizo, Verónica E; Pineda, Carmen; Rodríguez-Ortiz, Maria E; Rodríguez, Mariano; Aguilera-Tejero, Escolástico; Rivero, José-Luis L

    2015-10-01

    This study describes fiber-type adaptations in hindlimb muscles, the interaction of sex, and the role of hypoxia on this response in 12-wk ⅚ nephrectomized rats (Nx). Contractile, metabolic, and morphological features of muscle fiber types were assessed in the slow-twitch soleus and the fast-twitch tibialis cranialis muscles of Nx rats, and compared with sham-operated controls. Rats of both sexes were considered in both groups. A slow-to-fast fiber-type transformation occurred in the tibialis cranialis of Nx rats, particularly in males. This adaptation was accomplished by impaired oxidative capacity and capillarity, increased glycolytic capacity, and no changes in size and nuclear density of muscle fiber types. An oxidative-to-glycolytic metabolic transformation was also found in the soleus muscle of Nx rats. However, a modest fast-to-slow fiber-type transformation, fiber hypertrophy, and nuclear proliferation were observed in soleus muscle fibers of male, but not of female, Nx rats. Serum testosterone levels decreased by 50% in male but not in female Nx rats. Hypoxia-inducible factor-1α protein level decreased by 42% in the tibialis cranialis muscle of male Nx rats. These data demonstrate that 12 wk of Nx induces a muscle-specific adaptive response in which myofibers do not change (or enlarge minimally) in size and nuclear density, but acquire markedly different contractile and metabolic characteristics, which are accompanied by capillary rarefaction. Muscle function and sex play relevant roles in these adaptations. PMID:26246512

  17. Trigeminal Proprioception Evoked by Strong Stretching of the Mechanoreceptors in Müller's Muscle Induces Reflex Contraction of the Orbital Orbicularis Oculi Slow-Twitch Muscle Fibers

    PubMed Central

    Ban, Ryokuya; Ban, Midori; Yuzuriha, Shunsuke

    2014-01-01

    Objective: The mixed orbicularis oculi muscle lacks an intramuscular proprioceptive system such as muscle spindles, to induce reflex contraction of its slow-twitch fibers. We evaluated whether the mechanoreceptors in Müller's muscle function as extrinsic mechanoreceptors to induce reflex contraction of the slow-twitch fibers of the orbicularis oculi in addition to those of the levator and frontalis muscles. Methods: We evaluated in patients with aponeurosis-disinserted blepharoptosis whether strong stretching of the mechanoreceptors in Müller's muscle from upgaze with unilateral lid load induced reflex contraction of the orbicularis oculi slow-twitch fibers and whether anesthesia of Müller's muscle precluded the contraction. We compared the electromyographic responses of the bilateral orbicularis oculi muscles to unilateral intraoperative direct stimulation of the trigeminal proprioceptive nerve with those to unilateral transcutaneous electrical stimulation of the supraorbital nerve. Results: Upgaze with a unilateral 3-g lid load induced reflex contraction of the bilateral orbicularis oculi muscles with ipsilateral dominance. Anesthesia of Müller's muscle precluded the reflex contraction. The orbicularis oculi reflex evoked by stimulation of the trigeminal proprioceptive nerve differed from that by electrical stimulation of the supraorbital nerve in terms of the intensity of current required to induce the reflex, the absence of R1, and duration. Conclusions: The mechanoreceptors in Müller's muscle functions as an extramuscular proprioceptive system to induce reflex contraction of the orbital orbicularis oculi slow-twitch fibers. Whereas reflex contraction of the pretarsal orbicularis fast-twitch fibers functions in spontaneous or reflex blinking, that of the orbital orbicularis oculi slow-twitch fibers may factor in grimacing and blepharospasm. PMID:25210572

  18. Effects of tension and stiffness due to reduced pH in mammalian fast- and slow-twitch skinned skeletal muscle fibres.

    PubMed Central

    Metzger, J M; Moss, R L

    1990-01-01

    1. The pH dependence of the Ca2+ sensitivities of isometric tension and stiffness was investigated at 10 and 15 degrees C in skinned single fibres from rat and rabbit fast- and slow-twitch skeletal muscles. Stiffness was determined by recording the tension responses to sinusoidal length changes (3.3 kHz); peak-to-peak amplitude of the length change was monitored by laser diffraction and averaged approximately 1.3 nm (half-sarcomere)-1. We have assumed that stiffness provides a measure of the number of cross-bridge attachments to actin. 2. At maximal Ca2+ activation, stiffness was depressed by 22 +/- 2% (mean +/- S.E.M.) in fast-twitch fibres but was unchanged in slow-twitch fibres when pH was lowered from 7.00 to 6.20. As reported previously, maximum tension was depressed by 20-45% at low pH, with the effect being greater in fast-twitch compared to slow-twitch fibres. 3. In fast-twitch fibres at 10 and 15 degrees C the Ca2+ concentrations for half-maximal activation of tension and stiffness were increased at low pH. In slow-twitch fibres, similar effects were observed at 15 degrees C, but at 10 degrees C there were no changes in the Ca2+ sensitivities of tension and stiffness when pH was lowered. 4. Linear relationships between relative tension and relative stiffness were obtained at all temperatures, with slopes of 1.04 +/- 0.01 at pH 7.00 and 0.76 +/- 0.01 at pH 6.20 in fast- and slow-twitch fibres, indicating that force per cross-bridge attachment is similarly reduced at low pH in both types of fibres. 5. In both fast- and slow-twitch fibres, rigor tension (no added ATP or creatine phosphate; pCa 9.0) was depressed by 35 +/- 7% and stiffness by 12 +/- 4% when pH was reduced from 7.00 to 6.20. Since cross-bridge cycling is inhibited in rigor the effect of low pH to depress rigor tension suggests that pH directly modulates the strength of the bond formed between actin and myosin. 6. The effect of low pH to reduce the apparent number of cross-bridge attachments

  19. Differential microRNA Expression in Fast- and Slow-Twitch Skeletal Muscle of Piaractus mesopotamicus during Growth

    PubMed Central

    Duran, Bruno Oliveira da Silva; Fernandez, Geysson Javier; Mareco, Edson Assunção; Moraes, Leonardo Nazario; Salomão, Rondinelle Artur Simões; Gutierrez de Paula, Tassiana; Santos, Vander Bruno; Carvalho, Robson Francisco; Dal-Pai-Silvca, Maeli

    2015-01-01

    Pacu (Piaractus mesopotamicus) is a Brazilian fish with a high economic value in pisciculture due to its rusticity and fast growth. Postnatal growth of skeletal muscle in fish occurs by hyperplasia and/or hypertrophy, processes that are dependent on the proliferation and differentiation of myoblasts. A class of small noncoding RNAs, known as microRNAs (miRNAs), represses the expression of target mRNAs, and many studies have demonstrated that miR-1, miR-133, miR-206 and miR-499 regulate different processes in skeletal muscle through the mRNA silencing of hdac4 (histone deacetylase 4), srf (serum response factor), pax7 (paired box 7) and sox6 ((sex determining region Y)-box 6), respectively. The aim of our work was to evaluate the expression of these miRNAs and their putative target mRNAs in fast- and slow-twitch skeletal muscle of pacu during growth. We used pacus in three different development stages: larval (aged 30 days), juvenile (aged 90 days and 150 days) and adult (aged 2 years). To complement our study, we also performed a pacu myoblast cell culture, which allowed us to investigate miRNA expression in the progression from myoblast proliferation to differentiation. Our results revealed an inverse correlation between the expression of the miRNAs and their target mRNAs, and there was evidence that miR-1 and miR-206 may regulate the differentiation of myoblasts, whereas miR-133 may regulate the proliferation of these cells. miR-499 was highly expressed in slow-twitch muscle, which suggests its involvement in the specification of the slow phenotype in muscle fibers. The expression of these miRNAs exhibited variations between different development stages and between distinct muscle twitch phenotypes. This work provides the first identification of miRNA expression profiles in pacu skeletal muscle and suggests an important role of these molecules in muscle growth and in the maintenance of the muscle phenotype. PMID:26529415

  20. Differential microRNA Expression in Fast- and Slow-Twitch Skeletal Muscle of Piaractus mesopotamicus during Growth.

    PubMed

    Duran, Bruno Oliveira da Silva; Fernandez, Geysson Javier; Mareco, Edson Assunção; Moraes, Leonardo Nazario; Salomão, Rondinelle Artur Simões; Gutierrez de Paula, Tassiana; Santos, Vander Bruno; Carvalho, Robson Francisco; Dal-Pai-Silva, Maeli; Dal-Pai-Silvca, Maeli

    2015-01-01

    Pacu (Piaractus mesopotamicus) is a Brazilian fish with a high economic value in pisciculture due to its rusticity and fast growth. Postnatal growth of skeletal muscle in fish occurs by hyperplasia and/or hypertrophy, processes that are dependent on the proliferation and differentiation of myoblasts. A class of small noncoding RNAs, known as microRNAs (miRNAs), represses the expression of target mRNAs, and many studies have demonstrated that miR-1, miR-133, miR-206 and miR-499 regulate different processes in skeletal muscle through the mRNA silencing of hdac4 (histone deacetylase 4), srf (serum response factor), pax7 (paired box 7) and sox6 ((sex determining region Y)-box 6), respectively. The aim of our work was to evaluate the expression of these miRNAs and their putative target mRNAs in fast- and slow-twitch skeletal muscle of pacu during growth. We used pacus in three different development stages: larval (aged 30 days), juvenile (aged 90 days and 150 days) and adult (aged 2 years). To complement our study, we also performed a pacu myoblast cell culture, which allowed us to investigate miRNA expression in the progression from myoblast proliferation to differentiation. Our results revealed an inverse correlation between the expression of the miRNAs and their target mRNAs, and there was evidence that miR-1 and miR-206 may regulate the differentiation of myoblasts, whereas miR-133 may regulate the proliferation of these cells. miR-499 was highly expressed in slow-twitch muscle, which suggests its involvement in the specification of the slow phenotype in muscle fibers. The expression of these miRNAs exhibited variations between different development stages and between distinct muscle twitch phenotypes. This work provides the first identification of miRNA expression profiles in pacu skeletal muscle and suggests an important role of these molecules in muscle growth and in the maintenance of the muscle phenotype. PMID:26529415

  1. Effect of halothane on isometric twitch and tetanus response and the associated heat production in striated muscle of frogs.

    PubMed

    Price, K A; Matsumoto, Y; Frederickson, E L

    1975-01-01

    The purpose of these investigations was to determine the effect of halothane on isometric contraction of striated muscle and to measure the associated heat production. This basic information is necessary before studies more directly relating to malignant hyperthermia are undertaken. Sartorius muscles were isolate from Rana pipiens during winter and summer months. It appears from these experiments that there is a prolongation of the relaxation phase of the twitch and tetanus responses with low concentrations of halothane, with a more diffuse effect on the contractile process evident at higher administered concentrations. The results of heat measurements, using a sensitive thermopile-galvanometer system, are compatible with the hypotheses that this effect on relaxation could result from either an interference with calcium reuptake by the sarcoplasmic reticulum or an increased affinity of the troponintropomyosin complex for available calcium. PMID:1080024

  2. Mutations in Type I and Type IV Pilus Biosynthetic Genes Affect Twitching Motility Rates in Xylella fastidiosa▿ †

    PubMed Central

    De La Fuente, Leonardo; Burr, Thomas J.; Hoch, Harvey C.

    2007-01-01

    Xylella fastidiosa possesses both type I and type IV pili at the same cell pole. By use of a microfluidic device, the speed of twitching movement by wild-type cells on a glass surface against the flow direction of media was measured as 0.86 (standard error [SE], 0.04) μm min−1. A type I pilus mutant (fimA) moved six times faster (4.85 [SE, 0.27] μm min−1) and a pilY1 mutant moved three times slower (0.28 [SE, 0.03] μm min−1) than wild-type cells. Type I pili slow the rate of movement, while the putative type IV pilus protein PilY1 is likely important for attachment to surfaces. PMID:17693510

  3. Cone Heads

    ERIC Educational Resources Information Center

    Coy, Mary

    2005-01-01

    The author, a middle school art teacher, describes a sculpture project lesson involving Cone Heads (sculptures made from cardboard cones). Discussion of caricatures with exaggerated facial features and interesting profiles helped students understand that the more expressive the face, the better. This project took approximately four to five…

  4. Use of mouth pressure twitches induced by cervical magnetic stimulation to assess voluntary activation of the diaphragm.

    PubMed

    de Bruin, P F; Watson, R A; Khalil, N; Pride, N B

    1998-09-01

    There is a need for a simple method to assess the adequacy of diaphragm activation during voluntary inspiratory efforts in patients with suspected respiratory muscle weakness. We have compared mouth (Pmo,t), oesophageal (Poes,t) and transdiaphragmatic (Pdi,t) twitch pressure elicited by cervical magnetic stimulation (CMS) in five normal men (mean (SD) age 32.2 (1.8) yrs) on two separate study days. Single magnetic stimuli were delivered at functional residual capacity during relaxation and during graded voluntary inspiratory efforts against a closed airway. As voluntary-effort transdiaphragmatic and oesophageal pressure increased, Pdi,t and Poes,t decreased linearly (r range, respectively, 0.82-0.98 and 0.87-0.95). During relaxation, Pmo,t was unreliable due to the poor transmission of intrathoracic pressure, but during inspiratory efforts, the relation between voluntary mouth pressure and Pmo,t was also linear (r range 0.84-0.95). On average, our subjects voluntarily generated 99, 100 and 102% of the maximum transdiaphragmatic, oesophageal and mouth pressures predicted by the respective linear regression equations. Pmo,t was correlated to both Poes,t and Pdi,t during inspiratory efforts, but not during relaxation. These studies confirm that twitch pressures induced by CMS during inspiratory efforts can be assessed at the mouth in normal subjects, providing a simple and non-invasive technique for assessing diaphragm activation during voluntary inspiratory efforts. Potentially, this technique could be made more sensitive and accurate and applied to detect submaximal efforts in patients. PMID:9762798

  5. Exhausting treadmill running causes dephosphorylation of sMLC2 and reduced level of myofilament MLCK2 in slow twitch rat soleus muscle

    PubMed Central

    Hortemo, Kristin Halvorsen; Aronsen, Jan Magnus; Lunde, Ida G; Sjaastad, Ivar; Lunde, Per Kristian; Sejersted, Ole M

    2015-01-01

    Myosin light chain 2 (MLC2) is a small protein in the myosin complex, regulating muscle contractile function by modulating Ca2+ sensitivity of myofilaments. MLC2 can be modified by phosphorylation and O-GlcNAcylation, two reversible and dynamic posttranslational modifications. The slow isoform of MLC2 (sMLC2) is dephosphorylated in soleus muscle during in situ loaded shortening contractions, which correlates with reduction in shortening capacity. Here, we hypothesize that exhausting in vivo treadmill running induces dephosphorylation of MLC2 in slow twitch soleus, but not in fast twitch EDL muscle, and that there are reciprocal changes in MLC2 O-GlcNAcylation. At rest, both phosphorylation and O-GlcNAcylation of MLC2 were lower in slow than fast twitch muscles. One bout of exhausting treadmill running induced dephosphorylation of sMLC2 in soleus, paralleled by reduced levels of the kinase MLCK2 associated to myofilaments, suggesting that the acute reduction in phosphorylation is mediated by dissociation of MLCK2 from myofilaments. O-GlcNAcylation of MLC2 did not change significantly, and seems of limited importance in the regulation of MLC2 phosphorylation during in vivo running. After 6 weeks of treadmill running, the dephosphorylation of sMLC2 persisted in soleus along with reduction in MLCK2 both in myofilament- and total protein fraction. In EDL on the contrary, phosphorylation of MLC2 was not altered after one exercise bout or after 6 weeks of treadmill running. Thus, in contrast to fast twitch muscle, MLC2 dephosphorylation occurs in slow twitch muscle during in vivo exercise and may be linked to reduced myofilament-associated MLCK2 and reduced shortening capacity. PMID:25713325

  6. Recovery from immobilisation: responses of fast-twitch muscle fibres to spontaneous and intensive exercise in rat calf muscles.

    PubMed

    Venojärvi, M.; Kvist, M.; Atalay, M.; Jozsa, L.; Kalimo, H.

    2004-07-01

    Four weeks of immobilisation with two types of re-mobilisation programmes (intensive concentric treadmill exercising during 6 days, and free exercising, and immobilisation without any re-mobilisation period were studied to clarify possible exercise-induced calf muscle damage especially in fast-twitch fibres used in running compared to non-immobilised rats housing freely in their cages. As markers of muscle injury, conventional histology, beta-glucuronidase (beta-GU) activity and fetal myosin heavy chain expression (MHC-d) were assessed on Days 0, 1, 3, 6 and 14 after the cast removal. Only minor focal hypercontraction, ruptures and necrosis of myofibrils, and weak inflammatory cell reactions were found in all samples examined, except in the controls. No MHC-d positive cells were found indicating absence of active regeneration after immobilisation or re-mobilisation. Minor increase in beta-GU activity was observed in all three muscles studied, but statistically significant increase was observed only in the samples of the free exercising group on Day 14 after the cast removal. To conclude, intensive concentric treadmill exercise for 6 days did not cause significantly more muscle damage than did free exercising re-mobilisation. PMID:15177511

  7. Drug action of benzocaine on the sarcoplasmic reticulum Ca-ATPase from fast-twitch skeletal muscle.

    PubMed

    Di Croce, D; Trinks, P W; Grifo, M B; Takara, D; Sánchez, G A

    2015-11-01

    The effect of the local anesthetic benzocaine on sarcoplasmic reticulum membranes isolated from fast-twitch muscles was tested. The effects on Ca-ATPase activity, calcium binding and uptake, phosphoenzyme accumulation and decomposition were assessed using radioisotopic methods. The calcium binding to the Ca-ATPase was noncompetitively inhibited, and the enzymatic activity decreased in a concentration-dependent manner (IC50 47.1 mM). The inhibition of the activity depended on the presence of the calcium ionophore calcimycin and the membrane protein concentration. The pre-exposure of the membranes to benzocaine enhanced the enzymatic activity in the absence of calcimycin, supporting the benzocaine permeabilizing effect, which was prevented by calcium. Benzocaine also interfered with the calcium transport capability by decreasing the maximal uptake (IC50 40.3 mM) without modification of the calcium affinity for the ATPase. It inhibited the phosphorylation of the enzyme, and at high benzocaine concentration, the dephosphorylation step became rate-limiting as suggested by the biphasic profile of phosphoenzyme accumulation at different benzocaine concentrations. The data reported in this paper revealed a complex pattern of inhibition involving two sites for interaction with low and high benzocaine concentrations. It is concluded that benzocaine not only exerts an indirect action on the membrane permeability to calcium but also affects key steps of the Ca-ATPase enzymatic cycle. PMID:26173386

  8. Regenerating tail muscles in lizard contain Fast but not Slow Myosin indicating that most myofibers belong to the fast twitch type for rapid contraction.

    PubMed

    Alibardi, L

    2015-10-01

    During tail regeneration in lizards a large mass of muscle tissue is formed in form of segmental myomeres of similar size located under the dermis of the new tail. These muscles accumulate glycogen and a fast form of myosin typical for twitch myofibers as it is shown by light and ultrastructural immunocytochemistry using an antibody directed against a Fast Myosin Heavy Chain. High resolution immunogold labeling shows that an intense labeling for fast myosin is localized over the thick filaments of the numerous myofibrils in about 70% of the regenerated myofibers while the labeling becomes less intense in the remaining muscle fibers. The present observations indicate that at least two subtypes of Fast Myosin containing muscle fibers are regenerated, the prevalent type was of the fast twitch containing few mitochondria, sparse glycogen, numerous smooth endoplasmic reticulum vesicles. The second, and less frequent type was a Fast-Oxidative-Glycolitic twitch fiber containing more mitochondria, a denser cytoplasm and myofibrils. Since their initial differentiation, myoblasts, myotubes and especially the regenerated myofibers do not accumulate any immuno-detectable Slow Myosin Heavy Chain. The study indicates that most of the segmental muscles of the regenerated tail serve for the limited bending of the tail during locomotion and trashing after amputation of the regenerated tail, a phenomenon that facilitates predator escape. PMID:26164738

  9. Preclinical profile of the mixed 5-HT1A/5-HT2A receptor antagonist S 21,357.

    PubMed

    Griebel, G; Blanchard, D C; Rettori, M C; Guardiola-Lemaître, B; Blanchard, R J

    1996-06-01

    This study evaluated the pharmacological and behavioral effects of S 21,357, a drug with high affinity for both 5-HT1A and 5-HT2A receptors. The drug behaved as antagonist at both 5-HT1A autoreceptors and postsynaptic 5-HT1A receptors, as it prevented the inhibitory effect of lesopitron on the electrical discharge of the dorsal raphé nucleus (DRN) 5-HT neurons and the activity of forskolin-stimulated adenylate cyclase in hippocampal homogenates. In addition, S 21,357 (4 and 128 mg/kg, PO) inhibited 5-HTP-induced head-twitch responses in mice, indicating that it possesses 5-HT2A antagonistic properties. In a test battery designed to assess defensive behaviors of Swiss-Webster mice to the presence of, or situations associated with, a natural threat stimulus (i.e., rat), S 21,357 (0.12-2 mg/kg, IP) reduced contextual defense reactions after the rat was removed, risk assessment activities when the subject was chased, and finally, defensive attack behavior. These behavioral changes are consistent with fear/anxiety reduction. Furthermore, the drug strongly reduced flight reactions in response to the approaching rat. This last finding, taken together with recent results with panic-modulating drugs, suggest that S 21,357 may have potential efficacy against panic attack. Finally, our results suggest that compounds sharing high affinities for both 5-HT1A and 5-HT2A receptors may directly or synergistically increase the range of defensive behaviors affected. PMID:8743616

  10. Interaction of Mechanical Load with Growth Hormone (GH) and Insulin-Like Growth Factor I (IGF-I) on Slow-Twitch Skeletal Muscle and Bone

    NASA Technical Reports Server (NTRS)

    Linderman, Jon K.; Gosselink, Kristin L.; Wang, Tommy J.; Mukku, Venkat R.; Grindeland, Richard E.

    1994-01-01

    Exogenous humoral growth factors, combined with increased mechanical loading, reportedly induce hypertrophy of fast-, but not slow-twitch skeletal muscles, and have little effect in attenuating atrophy of slow-twitch muscle associated with exposure to microgravity in animals with intact neuroendocrine systems. These observations suggest that anabolic adjuvants and muscle tension do not interact to stimulate growth or maintenance of slow-twitch skeletal muscle. The purpose of the present study was to determine whether a chronic increase in mechanical loading (synergistic ablation) or hindlimb unweighting (hindlimb suspension) interact with exogenous GH and IGF-I (Genentech, So San Francisco, CA) in the slow-twitch soleus muscles of female rats (approx. 250 g). Bilateral ablation of the plantaris and gastrocnemius muscles induced 38% and 40% increases in the absolute (mg/pair) and relative (mg/100 g body weight) weights of the soleus, respectively (p less than or = 0.05), in ambulatory rats. GH and IGF-I interacted with chronic loading to increase absolute soleus mass an additional 20% (p less than or = 0.05), and mixed and myofibrillar protein contents an additional 12% and 7%, respectively (NS). In contrast, hindlimb suspension (HLS) resulted in 20% and 18% decreases in the absolute and relative weights of the soleus, respectively (p less than or = 0.05); GH and IGF-I did not spare loss of soleus mass or protein content in HLS rats. HLS decreased tibial plate thickness approx. 11% (p less than or = 0.05), but not weights of the tibia or femus. GH and IGF-I increased tibial plate thickness approx. 30% (p less than or = 0.05), in ambulatory and HLS rats, and increased femur and tibial weights 12% (p less than or = 0.05) and 8% (NS), respectively, in ambulatory rats, but had no effect in HLS rats. Results of the present investigation suggest that GH and IGF-I can stimulate hypertrophy of slow-twitch skeletal muscle when chronically overloaded, but can also stimulate

  11. Effects of MgATP and MgADP on the cross-bridge kinetics of rabbit soleus slow-twitch muscle fibers.

    PubMed Central

    Wang, G; Kawai, M

    1996-01-01

    The elementary steps surrounding the nucleotide binding step in the cross-bridge cycle were investigated with sinusoidal analysis in rabbit soleus slow-twitch muscle fibers. The single-fiber preparations were activated at pCa 4.40, ionic strength 180 mM, 20 degrees C, and the effects of MgATP (S) and MgADP (D) concentrations on three exponential processes B, C, and D were studied. Our results demonstrate that all apparent (measured) rate constants increased and saturated hyperbolically as the MgATP concentration was increased. These results are consistent with the following cross-bridge scheme: [cross-bridge scheme: see text] where A = actin, M = myosin, S = MgATP, and D = MgADP. AM+S is a collision complex, and AM*S is its isomerized form. From our studies, we obtained K0 = 18 +/- 4 mM-1 (MgADP association constant, N = 7, average +/- sem), K1a = 1.2 +/- 0.3 mM-1 (MgATP association constant, N = 8 hereafter), k1b = 90 +/- 20 s-1 (rate constant of ATP isomerization), k-1b = 100 +/- 9 s-1 (rate constant of reverse isomerization), K1b = 1.0 +/- 0.2 (equilibrium constant of isomerization), k2 = 21 +/- 3 s-1 (rate constant of cross-bridge detachment), k-2 = 14.1 +/- 1.0 s-1 (rate constant of reversal of detachment), and K2 = 1.6 +/- 0.3 (equilibrium constant of detachment). K0 is 8 times and K1a is 2.2 times those in rabbit psoas, indicating that nucleotides bind to cross-bridges more tightly in soleus slow-twitch muscle fibers than in psoas fast-twitch muscle fibers. These results indicate that cross-bridges of slow-twitch fibers are more resistant to ATP depletion than those of fast-twitch fibers. The rate constants of ATP isomerization and cross-bridge detachment steps are, in general, one-tenth to one-thirtieth of those in psoas. PMID:8874019

  12. Abnormal Head Position

    MedlinePlus

    ... cause. Can a longstanding head turn lead to any permanent problems? Yes, a significant abnormal head posture could cause permanent ... occipitocervical synostosis and unilateral hearing loss. Are there any ... postures? Yes. Abnormal head postures can usually be improved depending ...

  13. Head and face reconstruction

    MedlinePlus

    Head and face reconstruction is surgery to repair or reshape deformities of the head and face (craniofacial). ... How surgery for head and face deformities (craniofacial reconstruction) ... and the person's condition. Surgical repairs involve the ...

  14. Head circumference (image)

    MedlinePlus

    Head circumference is a measurement of the circumference of the child's head at its largest area (above the eyebrows and ears and around the back of the head). During routine check-ups, the distance is measured ...

  15. Head Injury Prevention Tips

    MedlinePlus

    Head Injury Prevention Tips American Association of Neurological Surgeons 5550 Meadowbrook Drive, Rolling Meadows, IL 60008-3852 ... defined as a blow or jolt to the head or a penetrating head injury that disrupts the ...

  16. S1P3 receptor influences key physiological properties of fast-twitch extensor digitorum longus muscle.

    PubMed

    Germinario, Elena; Bondì, Michela; Cencetti, Francesca; Donati, Chiara; Nocella, Marta; Colombini, Barbara; Betto, Romeo; Bruni, Paola; Bagni, Maria Angela; Danieli-Betto, Daniela

    2016-06-01

    To examine the role of sphingosine 1-phosphate (S1P) receptor 3 (S1P3) in modulating muscle properties, we utilized transgenic mice depleted of the receptor. Morphological analyses of extensor digitorum longus (EDL) muscle did not show evident differences between wild-type and S1P3-null mice. The body weight of 3-mo-old S1P3-null mice and the mean cross-sectional area of transgenic EDL muscle fibers were similar to those of wild-type. S1P3 deficiency enhanced the expression level of S1P1 and S1P2 receptors mRNA in S1P3-null EDL muscle. The contractile properties of S1P3-null EDL diverge from those of wild-type, largely more fatigable and less able to recover. The absence of S1P3 appears responsible for a lower availability of calcium during fatigue. S1P supplementation, expected to stimulate residual S1P receptors and signaling, reduced fatigue development of S1P3-null muscle. Moreover, in the absence of S1P3, denervated EDL atrophies less than wild-type. The analysis of atrophy-related proteins in S1P3-null EDL evidences high levels of the endogenous regulator of mitochondria biogenesis peroxisome proliferative-activated receptor-γ coactivator 1α (PGC-1α); preserving mitochondria could protect the muscle from disuse atrophy. In conclusion, the absence of S1P3 makes the muscle more sensitive to fatigue and slows down atrophy development after denervation, indicating that S1P3 is involved in the modulation of key physiological properties of the fast-twitch EDL muscle. PMID:26718782

  17. Heading and head injuries in soccer.

    PubMed

    Kirkendall, D T; Jordan, S E; Garrett, W E

    2001-01-01

    In the world of sports, soccer is unique because of the purposeful use of the unprotected head for controlling and advancing the ball. This skill obviously places the player at risk of head injury and the game does carry some risk. Head injury can be a result of contact of the head with another head (or other body parts), ground, goal post, other unknown objects or even the ball. Such impacts can lead to contusions, fractures, eye injuries, concussions or even, in rare cases, death. Coaches, players, parents and physicians are rightly concerned about the risk of head injury in soccer. Current research shows that selected soccer players have some degree of cognitive dysfunction. It is important to determine the reasons behind such deficits. Purposeful heading has been blamed, but a closer look at the studies that focus on heading has revealed methodological concerns that question the validity of blaming purposeful heading of the ball. The player's history and age (did they play when the ball was leather and could absorb significant amounts of water), alcohol intake, drug intake, learning disabilities, concussion definition and control group use/composition are all factors that cloud the ability to blame purposeful heading. What does seem clear is that a player's history of concussive episodes is a more likely explanation for cognitive deficits. While it is likely that the subconcussive impact of purposeful heading is a doubtful factor in the noted deficits, it is unknown whether multiple subconcussive impacts might have some lingering effects. In addition, it is unknown whether the noted deficits have any affect on daily life. Proper instruction in the technique is critical because if the ball contacts an unprepared head (as in accidental head-ball contacts), the potential for serious injury is possible. To further our understanding of the relationship of heading, head injury and cognitive deficits, we need to: learn more about the actual impact of a ball on the

  18. Desensitization of the Mechanoreceptors in Müller's Muscle Reduces the Increased Reflex Contraction of the Orbicularis Oculi Slow-Twitch Fibers in Blepharospasm

    PubMed Central

    Ban, Ryokuya; Ban, Midori

    2014-01-01

    Objective: Although the mixed orbicularis oculi muscle lacks the muscle spindles required to induce reflex contraction of its slow-twitch fibers, the mechanoreceptors in Müller's muscle function as extrinsic mechanoreceptors to induce reflex contraction. We hypothesize that strong stretching of these mechanoreceptors increases reflex contraction of the orbicularis oculi slow-twitch muscle fibers, resulting in blepharospasm. Methods: We examined a 71-year-old man with right blepharospasm and bilateral aponeurosis-disinserted blepharoptosis to determine whether the patient's blepharospasm was worsened by increased trigeminal proprioceptive evocation via stretching of the mechanoreceptors in Müller's muscle owing to a 60° upward gaze and serrated eyelid closure, and whether local anesthesia of the mechanoreceptors via lidocaine administration to the upper fornix as well as surgical disinsertion of Müller's muscle from the tarsus and fixation of the disinserted aponeurosis to the tarsus decreased trigeminal proprioceptive evocation and improved patient's blepharospasm. Results: Before pharmacological desensitization, 60° upward gaze and serrated eyelid closure exacerbated the patient's blepharospasm. In contrast, these maneuvers did not worsen his blepharospasm following lidocaine administration. One year after surgical desensitization, the blepharospasm had disappeared and a 60° upward gaze did not induce blepharospasm. Conclusions: Strong stretching of the mechanoreceptors in Müller's muscle appeared to increase reflex contraction of the orbicularis oculi slow-twitch muscle fibers, resulting in blepharospasm. In addition to botulinum neurotoxin injections into the involuntarily contracted orbicularis oculi muscle and myectomy, surgical desensitization of the mechanoreceptors in Müller's muscle may represent an additional procedure to reduce blepharospasm. PMID:25328566

  19. Biophysics: Alive and twitching

    NASA Astrophysics Data System (ADS)

    Smith, Ana-Sunčana

    2016-05-01

    Living systems are constantly being driven out of equilibrium by consuming energy. Studying fluctuations can tell us how they do so while maintaining order -- and what this teaches us about non-equilibrium processes in general.

  20. Differentiation of the intracellular structure of slow- versus fast-twitch muscle fibers through evaluation of the dielectric properties of tissue

    NASA Astrophysics Data System (ADS)

    Sanchez, B.; Li, J.; Bragos, R.; Rutkove, S. B.

    2014-05-01

    Slow-twitch (type 1) skeletal muscle fibers have markedly greater mitochondrial content than fast-twitch (type 2) fibers. Accordingly, we sought to determine whether the dielectric properties of these two fiber types differed, consistent with their distinct intracellular morphologies. The longitudinal and transverse dielectric spectrum of the ex vivo rat soleus (a predominantly type 1 muscle) and the superficial layers of rat gastrocnemius (predominantly type 2) (n = 15) were measured in the 1 kHz-10 MHz frequency range and modeled to a resistivity Cole-Cole function. Major differences were especially apparent in the dielectric spectrum in the 1 to 10 MHz range. Specifically, the gastrocnemius demonstrated a well-defined, higher center frequency than the soleus muscle, whereas the soleus muscle showed a greater difference in the modeled zero and infinite resistivities than the gastrocnemius. These findings are consistent with the fact that soleus tissue has larger and more numerous mitochondria than gastrocnemius. Evaluation of tissue at high frequency could provide a novel approach for assessing intracellular structure in health and disease.

  1. Head injury. Second edition

    SciTech Connect

    Cooper, P.R.

    1987-01-01

    This book contains 22 chapters. Some of the chapter titles are: Radiographic Evaluation; Epidemiology of Head Injury; Emergency Care and Initial Evaluation; Skull Fracture and Traumatic Cerebrospinal Fluid Fistulas; Mild Head Injury; and Injuries of the Cranial Nerves.

  2. Radial head fracture - aftercare

    MedlinePlus

    Elbow fracture - radial head - aftercare ... the radius bone, just below your elbow. A fracture is a break in your bone. The most common cause of a radial head fracture is falling with an outstretched arm.

  3. Head injury - first aid

    MedlinePlus

    ... medlineplus.gov/ency/article/000028.htm Head injury - first aid To use the sharing features on this page, ... a concussion can range from mild to severe. First Aid Learning to recognize a serious head injury and ...

  4. Increased head circumference

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003305.htm Increased head circumference To use the sharing features on this page, please enable JavaScript. Increased head circumference is when the measured distance around the ...

  5. Head and Neck Cancer

    MedlinePlus

    Head and neck cancer includes cancers of the mouth, nose, sinuses, salivary glands, throat, and lymph nodes in the ... increases your risk. In fact, 85 percent of head and neck cancers are linked to tobacco use, including smoking ...

  6. Head injury - first aid

    MedlinePlus

    ... is shaken, is the most common type of traumatic brain injury. Scalp wounds. Skull fractures. Head injuries may cause ... of people who suffer head injuries are children. Traumatic brain injury (TBI) accounts for over 1 in 6 injury- ...

  7. Head and Neck Cancer

    MedlinePlus

    Head and neck cancer includes cancers of the mouth, nose, sinuses, salivary glands, throat, and lymph nodes in the ... swallowing A change or hoarseness in the voice Head and neck cancers are twice as common in men. Using ...

  8. Head Start Facilities Manual.

    ERIC Educational Resources Information Center

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

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

  9. The Head Start Debates

    ERIC Educational Resources Information Center

    Zigler, Edward, Ed.; Styfco, Sally J., Ed.

    2004-01-01

    The future of Head Start depends on how well people learn from and apply the lessons from its past. That's why everyone involved in early education needs this timely, forward-thinking book from the leader of Head Start. The first book to capture the Head Start debates in all their complexity and diversity, this landmark volume brings together the…

  10. Pediatric head trauma

    PubMed Central

    Alexiou, George A; Sfakianos, George; Prodromou, Neofytos

    2011-01-01

    Head injury in children accounts for a large number of emergency department visits and hospital admissions. Falls are the most common type of injury, followed by motor-vehicle-related accidents. In the present study, we discuss the evaluation, neuroimaging and management of children with head trauma. Furthermore, we present the specific characteristics of each type of pediatric head injury. PMID:21887034

  11. The time course of early changes in the rate of tension development in electrically-stimulated frog toe muscle: effects of muscle length, temperature and twitch-potentiators

    PubMed Central

    Foulks, J. G.; Perry, Florence A.

    1966-01-01

    1. An RC circuit employing a piezo-electric crystal was used to differentiate the tension output of electrically stimulated frog toe muscle. 2. The rate of tension development curves (dP/dt) usually displayed an initial step-wise increase in the rate of tension development, and often showed further discernible steps in tension acceleration. The successive stages of tension acceleration tended to be equal in duration, and approximated the length of the latent period (ca. 4 msec at room temperature). These observations suggest a synchronous turnover of the links between the myofilaments during the initial interval following stimulation, with an over-all cycle time at room temperature of about 8 msec. 3. Lowering the temperature produced proportionate alterations in the duration as well as the magnitude of each successive phase of tension development, with a Q10 of approximately 2. 4. Characteristic changes in the pattern of tension generation were seen with alterations in muscle length, and at lengths greater than 120% of the standard length the irregularities in the dP/dt curves disappeared and the rate of tension development increased in linear fashion. This behaviour could be accounted for by the hypothetical S-filaments connecting the free ends of the thin actin filaments across the H-zone. 5. The effects of nine twitch potentiators were studied. Only perchlorate produced prominent increases in the earliest phase of tension development and in maximum tetanus tension—properties expected with an increase in the excitation-induced release of calcium ion into the sarcoplasm (increased intensity of the `active state'). 6. The time of onset of the increases in tension acceleration which were produced by twitch potentiators did not correlate with their capacity to lower the `mechanical threshold', indicating that the amount of calcium released by the action potential is not necessarily altered by a shift in the membrane potential at which calcium release occurs. 7

  12. Effect of spaceflight on the maximal shortening velocity, morphology, and enzyme profile of fast- and slow-twitch skeletal muscle fibers in rhesus monkeys

    NASA Technical Reports Server (NTRS)

    Fitts, R. H.; Romatowski, J. G.; De La Cruz, L.; Widrick, J. J.; Desplanches, D.

    2000-01-01

    Weightlessness has been shown to cause limb muscle wasting and a reduced peak force and power in the antigravity soleus muscle. Despite a reduced peak power, Caiozzo et al. observed an increased maximal shortening velocity in the rat soleus muscle following a 14-day space flight. The major purpose of the present investigation was to determine if weightlessness induced an elevated velocity in the antigravity slow type I fibers of the rhesus monkey (Macaca mulatta), as well as to establish a cellular mechanism for the effect. Spaceflight or models of weightlessness have been shown to increase glucose uptake, elevate muscle glycogen content, and increase fatigability of the soleus muscle. The latter appears to be in part caused by a reduced ability of the slow oxidative fibers to oxidize fats. A second goal of this study was to establish the extent to which weightlessness altered the substrate profile and glycolytic and oxidative enzyme capacity of individual slow- and fast-twitch fibers.

  13. Altered glucose 1,6-bisphosphate and fructose 2,6-biphosphate levels in low-frequency stimulated rabbit fast-twitch muscle.

    PubMed

    Green, H J; Cadefau, J; Pette, D

    1991-04-22

    Glucose 1,6-bisphosphate (Glc-1,6-P2) and fructose 2,6-bisphosphate (Fru-2,6-P2) concentrations display pronounced increases in rabbit fast-twitch muscle during chronic low-frequency stimulation. These increases are first seen after stimulation periods exceeding 3 h and reach maxima after 12-24 h of stimulation (approximately 3-fold for Glc-1,6-P2 and 5-fold for Fru-2,6-P2). Both metabolites regress to normal values after stimulation periods longer than 4 days. The fact that their increases coincide with the replenishment of glycogen after its initial depletion, could point to a role of Glc-1,6-P2 and Fru-2,6-P2 in glycogen metabolism. PMID:2026244

  14. The pilG gene product, required for Pseudomonas aeruginosa pilus production and twitching motility, is homologous to the enteric, single-domain response regulator CheY.

    PubMed Central

    Darzins, A

    1993-01-01

    The Pseudomonas aeruginosa pilG gene, encoding a protein which is involved in pilus production, was cloned by phenotypic complementation of a unique, pilus-defective mutant of strain PAO1. This mutant, designated FA2, although resistant to the pilus-specific phage D3112 was sensitive to the pilus-specific phages B3 and F116L. In spite of the unusual phage sensitivity pattern, FA2 lacked the ability to produce functional polar pili (pil) and was incapable of twitching motility (twt). Genetic analysis revealed that the FA2 pil mutation, designated pilG1, mapped near the met-28 marker located at 20 min and was distinct from the previously described pilT mutation. This map location was confirmed by localization of a 6.2-kb EcoRI fragment that complemented FA2 on the SpeI and DpnI physical map of the P. aeruginosa PAO1 chromosome. A 700-bp region encompassing the pilG gene was sequenced, and a 405-bp open reading frame, with characteristic P. aeruginosa codon bias, was identified. The molecular weight of the protein predicted from the amino acid sequence of PilG, which was determined to be 14,717, corresponded very closely to that of a polypeptide with the apparent molecular weight of 15,000 detected after expression of pilG from the T7 promoter in Escherichia coli. Moreover, the predicted amino acid sequence of PilG showed significant homology to that of the enteric CheY protein, a single-domain response regulator. A chromosomal pilG insertion mutant, constructed by allele replacement of the wild-type gene, was not capable of pilus production or twitching motility but displayed normal flagellum-mediated motility. These results, therefore, suggest that PilG may be an important part of the signal transduction system involved in the elaboration of P. aeruginosa pili. Images PMID:8104179

  15. Treatment of head lice.

    PubMed

    Diamantis, Stephanie A; Morrell, Dean S; Burkhart, Craig N

    2009-01-01

    Pediculosis capitis, or head lice, is a common infestation among children worldwide. Multiple therapies exist for the treatment of this condition, including topical pediculicides and oral medications. When used in combination with environmental decontamination, these drugs can be very effective in eradicating head lice infestation without significant adverse events. The present study discusses the use of available over-the-counter and prescription treatments, including pyrethroids and permethrin, lindane, malathion, ivermectin, and trimethoprim-sulfamethoxazole, in the treatment of head lice. PMID:19580574

  16. Deposition head for laser

    DOEpatents

    Lewis, Gary K.; Less, Richard M.

    1999-01-01

    A deposition head for use as a part of apparatus for forming articles from materials in particulate form in which the materials are melted by a laser beam and deposited at points along a tool path to form an article of the desired shape and dimensions. The deposition head delivers the laser beam and powder to a deposition zone, which is formed at the tip of the deposition head. A controller comprised of a digital computer directs movement of the deposition zone along the tool path and provides control signals to adjust apparatus functions, such as the speed at which the deposition head moves along the tool path.

  17. Bottom head assembly

    DOEpatents

    Fife, A.B.

    1998-09-01

    A bottom head dome assembly is described which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome. The bottom head dome has a plurality of openings extending there through. The liner also has a plurality of openings extending there through, and each liner opening aligns with a respective bottom head dome opening. A seal is formed, such as by welding, between the liner and the bottom head dome to resist entry of water between the liner and the bottom head dome at the edge of the liner. In the one embodiment, a plurality of stub tubes are secured to the liner. Each stub tube has a bore extending there through, and each stub tube bore is coaxially aligned with a respective liner opening. A seat portion is formed by each liner opening for receiving a portion of the respective stub tube. The assembly also includes a plurality of support shims positioned between the bottom head dome and the liner for supporting the liner. In one embodiment, each support shim includes a support stub having a bore there through, and each support stub bore aligns with a respective bottom head dome opening. 2 figs.

  18. Bottom head assembly

    DOEpatents

    Fife, Alex Blair

    1998-01-01

    A bottom head dome assembly which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome is described. The bottom head dome has a plurality of openings extending therethrough. The liner also has a plurality of openings extending therethrough, and each liner opening aligns with a respective bottom head dome opening. A seal is formed, such as by welding, between the liner and the bottom head dome to resist entry of water between the liner and the bottom head dome at the edge of the liner. In the one embodiment, a plurality of stub tubes are secured to the liner. Each stub tube has a bore extending therethrough, and each stub tube bore is coaxially aligned with a respective liner opening. A seat portion is formed by each liner opening for receiving a portion of the respective stub tube. The assembly also includes a plurality of support shims positioned between the bottom head dome and the liner for supporting the liner. In one embodiment, each support shim includes a support stub having a bore therethrough, and each support stub bore aligns with a respective bottom head dome opening.

  19. Head Injuries in Children

    ERIC Educational Resources Information Center

    Pennington, Nicole

    2010-01-01

    School nurses play a crucial role in injury prevention and initial treatment when injuries occur at school. The role of school nurses includes being knowledgeable about the management of head injuries, including assessment and initial treatment. The school nurse must be familiar with the outcomes of a head injury and know when further evaluation…

  20. American Head and Neck Society

    MedlinePlus

    American Head & Neck Society Head and Neck Cancer Research & Education American Head & Neck Society | AHNS Head and Neck Cancer Research & Education About AHNS ... and Announcements Copyright ©2016 · American Head and Neck Society · Privacy and Return Policy Managed by BSC Management, ...

  1. Trunnion-Head Stresses in THA: Are Big Heads Trouble?

    PubMed

    Lavernia, Carlos J; Iacobelli, David A; Villa, Jesus M; Jones, Kinzy; Gonzalez, Jose L; Jones, William Kinzy

    2015-06-01

    The effects of large heads on stresses at the THA trunnion-head junction and their impact on tribocorrosion/metal ion release remain controversial. A 12/14 3D-model of a stem with different head sizes was investigated. Material properties of titanium were assigned to the trunnion and cobalt-chrome/alumina to the heads. A load simulating walking single-leg stand phase was applied to the head. A total contact head-trunnion interface was assumed. The area underneath the junction underwent significant elevations in stresses as head size increased from 28- to 40-mm. Maximum principal stress doubled between 28 and 40-mm heads, regardless of head material. Stress levels had a direct correlation to head diameter. Stress increases observed using increasingly larger heads will probably contribute to head-trunnion tribocorrosion and ion release. PMID:25724112

  2. Head Circumference and Neurocognitive Outcomes.

    PubMed

    Millichap, J Gordon

    2015-07-01

    Investigators from Universities of Glasgow and Bristol, UK, determined the value of head circumference (HC) as a screening measure, the incidence of head centile shifting, and the relationship between extremes of head size and later neurodevelopmental problems. PMID:26933592

  3. ATP Consumption by SR Ca2+ Pumps Accounts for 50% of Resting Metabolic Rate in Mouse Fast and Slow Twitch Skeletal Muscle

    PubMed Central

    Norris, Sarah Michelle; Bombardier, Eric; Smith, Ian Curtis; Vigna, Chris; Tupling, Allan Russell

    2010-01-01

    The purpose of this study was to directly quantify the relative contribution of Ca2+ cycling to resting metabolic rate in mouse fast (extensor digitorum longus, EDL) and slow (soleus, SOL) twitch skeletal muscle. Resting oxygen consumption of isolated muscles (VO2, μL/g wet weight/s) measured polarographically at 30°C was ~25% higher in SOL (0.61 ± .03) than EDL (0.46 ± .03). In order to quantify the specific contribution of Ca2+ cycling to resting metabolic rate, cyclopiazonic acid (CPA), a highly specific inhibitor of sarco(endo)plasmic Ca2+ ATPases (SERCAs), was added to the bath at different concentrations (1, 5, 10 and 15 μM). There was a concentration-dependent effect of CPA on oxygen consumption with increasing CPA concentrations up to 10 μM resulting in progressively greater reductions in muscle VO2. There were no differences between 10 and 15 μM CPA indicating that 10 μM CPA induces maximal inhibition of SERCAs in isolated muscle preparations. The relative (%) reduction in muscle VO2 in response to CPA was nearly identical in EDL (1 μM, 10.6 ± 3.0; 5 μM, 33.2 ± 3.4; 10 μM, 49.2 ± 2.9; 15 μM, 50.9 ± 2.1) and SOL (1 μM, 11.2 ± 1.5; 5 μM, 37.7 ± 2.4; 10 μM, 50.0 ± 1.3; 15 μM, 49.9 ± 1.6). The results indicate that ATP consumption by SERCAs is responsible for ~50% of resting metabolic rate in both mouse fast- and slow-twitch muscles at 30°C. Thus, SERCA pumps in skeletal muscle could represent an important control point for energy balance regulation and a potential target for metabolic alterations to oppose obesity. PMID:20018953

  4. Maneuvering impact boring head

    DOEpatents

    Zollinger, W.T.; Reutzel, E.W.

    1998-08-18

    An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure. 8 figs.

  5. Maneuvering impact boring head

    DOEpatents

    Zollinger, W. Thor; Reutzel, Edward W.

    1998-01-01

    An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure.

  6. Head and Neck Cancer

    MedlinePlus

    ... head and neck cancer. Poor oral and dental hygiene . Poor care of the mouth and teeth has ... sore throat Foul mouth odor not explained by hygiene Hoarseness or change in voice Nasal obstruction or ...

  7. Head Lice: Treatment

    MedlinePlus

    ... it may be necessary to use a second bottle. Pay special attention to instructions on the label ... or printed on the label. Nit (head lice egg) combs, often found in lice medicine packages, should ...

  8. Overview of Head Injuries

    MedlinePlus

    ... to Baby Health Highlights: Sept. 13, 2016 Smokers' Perceptions May Play Role in Addiction Sugar Companies Shifted ... amount of oxygen given and the rate and depth of breaths given by the ventilator. The head ...

  9. Abnormal Head Position

    MedlinePlus

    ... syndrome, Brown’s syndrome, orbital wall fractures, and restricted eye movement associated with thyroid eye disease. 2) Nystagmus: Some patients with nystagmus (jerky eye movements) will acquire a head turn or tilt if ...

  10. Head CT scan

    MedlinePlus

    Brain CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - cranial ... or other growth (mass) Cerebral atrophy (loss of brain tissue) ... with the hearing nerve Stroke or transient ischemic attack (TIA)

  11. Ultrasound: Head (For Parents)

    MedlinePlus

    ... the head and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  12. Head tilt during driving.

    PubMed

    Zikovitz, D C; Harris, L R

    1999-05-01

    In order to distinguish between the use of visual and gravito-inertial force reference frames, the head tilt of drivers and passengers were measured as they went around corners at various speeds. The visual curvature of the corners were thus dissociated from the magnitude of the centripetal forces (0.30-0.77 g). Drivers' head tilts were highly correlated with the visually-available estimate of the curvature of the road (r2=0.86) but not with the centripetal force (r2<0.1). Passengers' head tilts were inversely correlated with the lateral forces (r2=0.3-0.7) and seem to reflect a passive sway. The strong correlation of the tilt of drivers' heads with a visual aspect of the road ahead, supports the use of a predominantly visual reference frame for the driving task. PMID:10722313

  13. TCGA head Neck

    Cancer.gov

    Investigators with The Cancer Genome Atlas (TCGA) Research Network have discovered genomic differences – with potentially important clinical implications – in head and neck cancers caused by infection with the human papillomavirus (HPV).

  14. Head Injuries in Soccer.

    ERIC Educational Resources Information Center

    Fields, Karl B.

    1989-01-01

    This article reviews the medical literature on head injuries in soccer and concludes that protective headgear to reduce these injuries may not be as effective as rule changes and other measures, such as padding goal posts. (IAH)

  15. Treating Head Lice

    MedlinePlus

    ... and Prevention. Head lice are most common among preschool children attending child care, elementary school children, and ... Emergency Preparedness International Programs News & Events Training & Continuing Education Inspections & Compliance Federal, State & Local Officials Consumers Health ...

  16. Swimming, swarming, twitching, and chemotactic responses of Cupriavidus metallidurans CH34 and Pseudomonas putida mt2 in the presence of cadmium.

    PubMed

    Shamim, Saba; Rehman, Abdul; Qazi, Mahmood Hussain

    2014-04-01

    To use of microorganisms for bioremediation purposes, the study of their motility behavior toward metals is essential. In the present study, Cupriavidus metallidurans CH34 and Pseudomonas putida mt2 were used as cadmium (Cd)-resistant and -sensitive bacteria, respectively, to evaluate the effects of Cd on their motility behaviors. Potassium morpholinopropane sulfonate (MOPS) buffer was used to observe the motility behavior of both isolates. Movement of mt2 was less in MOPS buffer compared with CH34, likely reflecting the mono-flagellated nature of mt2 and the peritrichous nature of CH34. The swimming, swarming, twitching, and chemotaxis behaviors of mt2 were greater in the presence of glucose than that of Cd. mt2 exhibited negative motility behaviors when exposed to Cd, but the opposite effect was seen in CH34. Cd was found to be a chemorepellent for mt2 but a chemoattractant for CH34, suggesting that CH34 is a potential candidate for metal (Cd) bioremediation. PMID:24306627

  17. Liver iron concentration measurements by MRI in chronically transfused children with sickle cell anemia: baseline results from the TWiTCH trial.

    PubMed

    Wood, John C; Pressel, Sara; Rogers, Zora R; Odame, Isaac; Kwiatkowski, Janet L; Lee, Margaret T; Owen, William C; Cohen, Alan R; St Pierre, Timothy; Heeney, Matthew M; Schultz, William H; Davis, Barry R; Ware, Russell E

    2015-09-01

    Noninvasive, quantitative, and accurate assessment of liver iron concentration (LIC) by MRI is useful for patients receiving transfusions, but R2 and R2* MRI techniques have not been systematically compared in sickle cell anemia (SCA). We report baseline LIC results from the TWiTCH trial, which compares hydroxyurea with blood transfusion treatment for primary stroke prophylaxis assessed by transcranial Doppler sonography in pediatric SCA patients. Liver R2 was collected and processed using a FDA-approved commercial process (FerriScan®), while liver R2* quality control and processing were performed by a Core Laboratory blinded to clinical site and patient data. Baseline LIC studies using both MRI techniques were available for 120 participants. LICR2* and LICR2 results were highly correlated (r(2)  = 0.93). A proportional bias of LIC(R2*)/LIC(R2), decreasing with average LIC, was observed. Systematic differences between LICR2* and LICR2 were also observed by MRI manufacturer. Importantly, LICR2* and LICR2 estimates had broad 95% limits of agreement with respect to each other. We recommend LICR2 and LICR2* not be used interchangeably in SCA patients to follow individual patient trends in iron burden. PMID:26087998

  18. Myosin Binding Protein-C Slow Phosphorylation is Altered in Duchenne Dystrophy and Arthrogryposis Myopathy in Fast-Twitch Skeletal Muscles

    PubMed Central

    Ackermann, Maegen A.; Ward, Christopher W.; Gurnett, Christina; Kontrogianni-Konstantopoulos, Aikaterini

    2015-01-01

    Myosin Binding Protein-C slow (sMyBP-C), encoded by MYBPC1, comprises a family of regulatory proteins of skeletal muscles that are phosphorylated by PKA and PKC. MYBPC1 missense mutations are linked to the development of Distal Arthrogryposis-1 (DA-1). Although structure-function details for this myopathy are evolving, function is undoubtedly driven by sequence variations and post-translational modifications in sMyBP-C. Herein, we examined the phosphorylation profile of sMyBP-C in mouse and human fast-twitch skeletal muscles. We used Flexor Digitorum Brevis (FDB) isolated from young (~2-months old) and old (~14-months old) wild type and mdx mice, and human Abductor Hallucis (AH) and gastrocnemious muscles carrying the DA-1 mutations. Our results indicate both constitutive and differential phosphorylation of sMyBP-C in aged and diseased muscles. We report a 7–35% reduction in the phosphorylation levels of select sites in old wild type and young or old mdx FDB mouse muscles, compared to young wild type tissue. Similarly, we observe a 30–70% decrease in the phosphorylation levels of all PKA and PKC phospho-sites in the DA-1 AH, but not gastrocnemius, muscle. Overall, our studies show that the phosphorylation pattern of sMyBP-C is differentially regulated in response to age and disease, suggesting that phosphorylation plays important roles in these processes. PMID:26287277

  19. Glucocorticoids regulate mRNA levels for subunits of the 19 S regulatory complex of the 26 S proteasome in fast-twitch skeletal muscles.

    PubMed Central

    Combaret, Lydie; Taillandier, Daniel; Dardevet, Dominique; Béchet, Daniel; Rallière, Cécile; Claustre, Agnès; Grizard, Jean; Attaix, Didier

    2004-01-01

    Circulating levels of glucocorticoids are increased in many traumatic and muscle-wasting conditions that include insulin-dependent diabetes, acidosis, infection, and starvation. On the basis of indirect findings, it appeared that these catabolic hormones are required to stimulate Ub (ubiquitin)-proteasome-dependent proteolysis in skeletal muscles in such conditions. The present studies were performed to provide conclusive evidence for an activation of Ub-proteasome-dependent proteolysis after glucocorticoid treatment. In atrophying fast-twitch muscles from rats treated with dexamethasone for 6 days, compared with pair-fed controls, we found (i) increased MG132-inhibitable proteasome-dependent proteolysis, (ii) an enhanced rate of substrate ubiquitination, (iii) increased chymotrypsin-like proteasomal activity of the proteasome, and (iv) a co-ordinate increase in the mRNA expression of several ATPase (S4, S6, S7 and S8) and non-ATPase (S1, S5a and S14) subunits of the 19 S regulatory complex, which regulates the peptidase and the proteolytic activities of the 26 S proteasome. These studies provide conclusive evidence that glucocorticoids activate Ub-proteasome-dependent proteolysis and the first in vivo evidence for a hormonal regulation of the expression of subunits of the 19 S complex. The results suggest that adaptations in gene expression of regulatory subunits of the 19 S complex by glucocorticoids are crucial in the regulation of the 26 S muscle proteasome. PMID:14636157

  20. Missouri: Early Head Start Initiative

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Missouri's Early Head Start/Child Care Partnership Project expands access to Early Head Start (EHS) services for children birth to age 3 by developing partnerships between federal Head Start, EHS contractors, and child care providers. Head Start and EHS contractors that participate in the initiative provide services through community child care…

  1. Head segmentation in vertebrates

    PubMed Central

    Kuratani, Shigeru; Schilling, Thomas

    2008-01-01

    Classic theories of vertebrate head segmentation clearly exemplify the idealistic nature of comparative embryology prior to the 20th century. Comparative embryology aimed at recognizing the basic, primary structure that is shared by all vertebrates, either as an archetype or an ancestral developmental pattern. Modern evolutionary developmental (Evo-Devo) studies are also based on comparison, and therefore have a tendency to reduce complex embryonic anatomy into overly simplified patterns. Here again, a basic segmental plan for the head has been sought among chordates. We convened a symposium that brought together leading researchers dealing with this problem, in a number of different evolutionary and developmental contexts. Here we give an overview of the outcome and the status of the field in this modern era of Evo-Devo. We emphasize the fact that the head segmentation problem is not fully resolved, and we discuss new directions in the search for hints for a way out of this maze. PMID:20607135

  2. Lubricating the swordfish head.

    PubMed

    Videler, John J; Haydar, Deniz; Snoek, Roelant; Hoving, Henk-Jan T; Szabo, Ben G

    2016-07-01

    The swordfish is reputedly the fastest swimmer on Earth. The concave head and iconic sword are unique characteristics, but how they contribute to its speed is still unknown. Recent computed tomography scans revealed a poorly mineralised area near the base of the rostrum. Here we report, using magnetic resonance imaging and electron microscopy scanning, the discovery of a complex organ consisting of an oil-producing gland connected to capillaries that communicate with oil-excreting pores in the skin of the head. The capillary vessels transport oil to abundant tiny circular pores that are surrounded by denticles. The oil is distributed from the pores over the front part of the head. The oil inside the gland is identical to that found on the skin and is a mixture of methyl esters. We hypothesize that the oil layer, in combination with the denticles, creates a super-hydrophobic layer that reduces streamwise friction drag and increases swimming efficiency. PMID:27385753

  3. rpoN1, but not rpoN2, is required for twitching motility, natural competence, growth on nitrate, and virulence of Ralstonia solanacearum

    PubMed Central

    Ray, Suvendra K.; Kumar, Rahul; Peeters, Nemo; Boucher, Christian; Genin, Stephane

    2015-01-01

    The plant pathogen Ralstonia solanacearum has two genes encoding for the sigma factor σ54: rpoN1, located in the chromosome and rpoN2, located in a distinct “megaplasmid” replicon. In this study, individual mutants as well as a double mutant of rpoN were created in R. solanacearum strain GMI1000 in order to determine the extent of functional overlap between these two genes. By virulence assay we observed that rpoN1 is required for virulence whereas rpoN2 is not. In addition rpoN1 controls other important functions such twitching motility, natural transformation and growth on nitrate, unlike rpoN2. The rpoN1 and rpoN2 genes have different expression pattern, the expression of rpoN1 being constitutive whereas rpoN2 expression is induced in minimal medium and in the presence of plant cells. Moreover, the expression of rpoN2 is dependent upon rpoN1. Our work therefore reveals that the two rpoN genes are not functionally redundant in R. solanacearum. A list of potential σ54 targets was identified in the R. solanacearum genome and suggests that multiple traits are under the control of these regulators. Based on these findings, we provide a model describing the functional connection between RpoN1 and the PehR pathogenicity regulator and their dual role in the control of several R. solanacearum virulence determinants. PMID:25852679

  4. High-resolution scanning electron-microscopic studies on the three-dimensional structure of mitochondria and sarcoplasmic reticulum in the different twitch muscle fibers of the frog.

    PubMed

    Ogata, T; Yamasaki, Y

    1987-12-01

    The three-dimensional structure of the mitochondria and sarcoplasmic reticulum (SR) in the three types of twitch fibers, i.e., the red, white and intermediate skeletal muscle fibers, of the vastus lateralis muscle of the Japanese meadow frog (Rana nigromaculata nigromaculata Hallowell) was examined by high resolution scanning electron microscopy, after removal of the cytoplasmic matrices. The small red fibers have numerous mitochondrial columns of large diameter, while the large white fibers have a small number of mitochondrial columns of small diameter. In the medium-size intermediate fibers, the number and diameter of the mitochondrial columns are intermediate between those of the red and white fibers. In all three types of fibers, the terminal cisternae and transverse tubules form triads at the level of each Z-line. The thick terminal cisternae continue into much thinner flat intermediate cisternae, through a transitional part where a row of tiny indentations can be observed. Numerous slender longitudinal tubules originating from the intermediate cisternae, extend longitudinally or obliquely and form elongated oval networks of various sizes in front of the A-band, then fuse to form the H-band collar (fenestrated collar) around the myofibrils. On the surface of the H-band collar, small fenestrations as well as tiny hollows are seen. The three-dimensional structure of SR is basically the same in all three muscle fiber-types. However, the SR is sparse on the surface of mitochondria, so the mitochondria-rich red fiber has a smaller total volume of SR than the mitochondria-poor white fiber. The volume of SR of the intermediate fiber is intermediate between other the two. PMID:3690630

  5. Relationship between first-twitch depression and train-of-four ratio during sugammadex reversal of rocuronium-induced neuromuscular blockade

    PubMed Central

    Oh, You Na; Kim, Tae Yeon; Oh, Song Yee; Sin, Yeong Hun

    2016-01-01

    Background The primary outcome of sugammadex reversal for rocuronium-induced neuromuscular block (NMB) is a train-of-four ratio (TOFR) of 0.9, not first twitch (T1) height. We investigated whether the recovery of TOFR or T1 differs based on the reversal of NMB with neostigmine or sugammadex. Methods The acceleromyographic responses from 0.6 mg/kg of rocuronium were monitored supramaximally in 80 patients after induction of anesthesia. The TOFR and T1 height were recorded, and saved in a personal computer using TOF-Watch SX Monitor software in all patients. Patients were randomly assigned to 2 groups to receive either neostigmine 50 µg/kg with glycopyrrolate 10 µg/kg (neostigmine group, n = 40) or sugammadex 2.0 mg/kg (sugammadex group, n = 40). The primary objective was to determine the difference of recovery time between TOFR to 0.9 and T1 to 0.9 after sugammadex or neostigmine administration during moderate rocuronium-induced NMB. Results The recovery pattern of the TOFR 2 min after sugammadex administration was 1.0 or more, but that of T1 was less than 90% (T1 / control value) up to 6 min after drug was injected. The recovery pattern of TOFR and T1 was similar during the 20 min after reversal with neostigmine. Conclusions If you have not performed the T1 monitoring, both TOFR and T1 should be considered to confirm suitable recovery during the 6 min after reversal with sugammadex during rocuronium-induced moderate NMB. PMID:27274368

  6. Reactor pressure vessel vented head

    DOEpatents

    Sawabe, James K.

    1994-01-11

    A head for closing a nuclear reactor pressure vessel shell includes an arcuate dome having an integral head flange which includes a mating surface for sealingly mating with the shell upon assembly therewith. The head flange includes an internal passage extending therethrough with a first port being disposed on the head mating surface. A vent line includes a proximal end disposed in flow communication with the head internal passage, and a distal end disposed in flow communication with the inside of the dome for channeling a fluid therethrough. The vent line is fixedly joined to the dome and is carried therewith when the head is assembled to and disassembled from the shell.

  7. Head Start Curriculum Guide.

    ERIC Educational Resources Information Center

    Smith, Clare Coe; And Others

    One of a series of guides for preschool teachers and aides, the book offers a Head Start curriculum guide to help achieve goals regarding social behavior, general attitudes, academic skills, health, and parent development. Information on curriculum is divided into areas of bloc time outline, classroom arrangement, building concepts (such as…

  8. Sculpting Ceramic Heads.

    ERIC Educational Resources Information Center

    Sapiro, Maurice

    1983-01-01

    Clay sculpture is difficult to produce because of the requirements of kiln firing. The problems can be overcome by modeling the original manikin head and making a plaster mold, pressing molding slabs of clay into the plaster mold to form the hollow clay armature, and sculpting on the armature. (IS)

  9. Imaging of head trauma.

    PubMed

    Rincon, Sandra; Gupta, Rajiv; Ptak, Thomas

    2016-01-01

    Imaging is an indispensable part of the initial assessment and subsequent management of patients with head trauma. Initially, it is important for diagnosing the extent of injury and the prompt recognition of treatable injuries to reduce mortality. Subsequently, imaging is useful in following the sequelae of trauma. In this chapter, we review indications for neuroimaging and typical computed tomography (CT) and magnetic resonance imaging (MRI) protocols used in the evaluation of a patient with head trauma. We review the role of CT), the imaging modality of choice in the acute setting, and the role of MRI in the evaluation of patients with head trauma. We describe an organized and consistent approach to the interpretation of imaging of these patients. Important topics in head trauma, including fundamental concepts related to skull fractures, intracranial hemorrhage, parenchymal injury, penetrating trauma, cerebrovascular injuries, and secondary effects of trauma, are reviewed. The chapter concludes with advanced neuroimaging techniques for the evaluation of traumatic brain injury, including use of diffusion tensor imaging (DTI), functional MRI (fMRI), and MR spectroscopy (MRS), techniques which are still under development. PMID:27432678

  10. MULTIPLE SHAFT TOOL HEAD

    DOEpatents

    Colbert, H.P.

    1962-10-23

    An improved tool head arrangement is designed for the automatic expanding of a plurality of ferruled tubes simultaneously. A plurality of output shafts of a multiple spindle drill head are driven in unison by a hydraulic motor. A plurality of tube expanders are respectively coupled to the shafts through individual power train arrangements. The axial or thrust force required for the rolling operation is provided by a double acting hydraulic cylinder having a hollow through shaft with the shaft cooperating with an internally rotatable splined shaft slidably coupled to a coupling rigidly attached to the respectlve output shaft of the drill head, thereby transmitting rotary motion and axial thrust simultaneously to the tube expander. A hydraulic power unit supplies power to each of the double acting cylinders through respective two-position, four-way valves, under control of respective solenoids for each of the cylinders. The solenoids are in turn selectively controlled by a tool selection control unit which in turn is controlled by signals received from a programmed, coded tape from a tape reader. The number of expanders that are extended in a rolling operation, which may be up to 42 expanders, is determined by a predetermined program of operations depending upon the arrangement of the ferruled tubes to be expanded in the tube bundle. The tape reader also supplies dimensional information to a machine tool servo control unit for imparting selected, horizontal and/or vertical movement to the tool head assembly. (AEC)

  11. Head, Neck, and Oral Cancer

    MedlinePlus

    ... Neck and Oral Pathology Head, Neck and Oral Pathology Close to 42,000 Americans will be diagnosed ... Neck and Oral Pathology Head, Neck and Oral Pathology Close to 42,000 Americans will be diagnosed ...

  12. Heads Up to High School Sports

    MedlinePlus

    ... Juvenil HEADS UP to School Sports Online Concussion Training Coaches Parents Athletes Sports Officials HEADS UP to Schools School Nurses Teachers, Counselors, and School Professionals Parents HEADS UP ...

  13. Minnesota: Early Head Start Initiatiive

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Minnesota provides supplemental state funding to existing federal Head Start and Early Head Start (EHS) grantees to increase their capacity to serve additional infants, toddlers, and pregnant women. The initiative was started in 1997 when the state legislature earmarked $1 million of the general state Head Start supplemental funds for children…

  14. Maryland Early Head Start Initiative

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Since 2000, Maryland has provided state supplemental funds to Head Start and Early Head Start (EHS) programs to improve access. Local EHS programs may use funds, through child care partnerships, to extend the EHS day or year. Maryland's approach to building on EHS includes: (1) Increase the capacity of existing Head Start and EHS programs to…

  15. MAGNETIC RECORDING HEAD

    DOEpatents

    Merrill, L.C.

    1958-06-17

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

  16. A new insight into the role of intracellular nickel levels for the stress response, surface properties and twitching motility by Haemophilus influenzae.

    PubMed

    Tikhomirova, Alexandra; Jiang, Donald; Kidd, Stephen P

    2015-04-01

    Nickel acts as a co-factor for a small number of enzymes in bacteria. Urease is one of the two nickel-dependent enzymes that have been identified in Haemophilus influenzae; glyoxalase I is the other. However, nickel has been suggested to have roles in H. influenzae that can not attributed to the function of these enzymes. We have previously shown that in the H. influenzae strain Rd KW20 the inability to acquire nickel led to alterations to the cell-type; an increased biofilm formation and changes in cell surface properties. Here we report the differences in the genome wide gene expression between Rd KW20 and a strain incapable of importing nickel (nikQ); revealing a link between intracellular nickel levels and genes involved in metabolic pathways, stress responses and genes associated with surface factors such as type IV pili. We have then taken a strain previously shown to use type IV pili both in biofilm formation and for twitching motility (86-028NP) and have shown its homologous genes (NTHI1417-1422; annotated as cobalt transporter, cbiKLMOQ) did import nickel and mutations in this locus had pleiotropic effects correlating to stress response and motility. Compared to wild type cells, the nickel depleted cells were more electronegativity charged, they aggregated and formed a biofilm. Correct intracellular nickel levels were also important for resistance to oxidative stress; the nickel depleted cells were more sensitive to oxidative stress. The nickel depleted cells were also non-motile, but the addition specifically of nickel returned these cells to a wild type motility state. We have also analysed the role of nickel uptake in a naturally, urease negative strain (the blood isolate R2866) and depleting intracellular nickel (a nikQ mutant) in this strain effected a similar range of cell functions. These data reveal a role for the capacity to acquire nickel from the environment and for the correct intracellular nickel levels as part of H. influenzae stress response

  17. Calcium buffering properties of sarcoplasmic reticulum and calcium-induced Ca2+ release during the quasi-steady level of release in twitch fibers from frog skeletal muscle

    PubMed Central

    Fénelon, Karine; Lamboley, Cédric R.H.; Carrier, Nicole

    2012-01-01

    Experiments were performed to characterize the properties of the intrinsic Ca2+ buffers in the sarcoplasmic reticulum (SR) of cut fibers from frog twitch muscle. The concentrations of total and free calcium ions within the SR ([CaT]SR and [Ca2+]SR) were measured, respectively, with the EGTA/phenol red method and tetramethylmurexide (a low affinity Ca2+ indicator). Results indicate SR Ca2+ buffering was consistent with a single cooperative-binding component or a combination of a cooperative-binding component and a linear binding component accounting for 20% or less of the bound Ca2+. Under the assumption of a single cooperative-binding component, the most likely resting values of [Ca2+]SR and [CaT]SR are 0.67 and 17.1 mM, respectively, and the dissociation constant, Hill coefficient, and concentration of the Ca-binding sites are 0.78 mM, 3.0, and 44 mM, respectively. This information can be used to calculate a variable proportional to the Ca2+ permeability of the SR, namely d[CaT]SR/dt ÷ [Ca2+]SR (denoted release permeability), in experiments in which only [CaT]SR or [Ca2+]SR is measured. In response to a voltage-clamp step to −20 mV at 15°C, the release permeability reaches an early peak followed by a rapid decline to a quasi-steady level that lasts ∼50 ms, followed by a slower decline during which the release permeability decreases by at least threefold. During the quasi-steady level of release, the release amplitude is 3.3-fold greater than expected from voltage activation alone, a result consistent with the recruitment by Ca-induced Ca2+ release of 2.3 SR Ca2+ release channels neighboring each channel activated by its associated voltage sensor. Release permeability at −60 mV increases as [CaT]SR decreases from its resting physiological level to ∼0.1 of this level. This result argues against a release termination mechanism proposed in mammalian muscle fibers in which a luminal sensor of [Ca2+]SR inhibits release when [CaT]SR declines to a low level

  18. Multilaser print head

    NASA Astrophysics Data System (ADS)

    Goodman, Douglas S.; Roblee, Jeffrey W.; Plummer, William T.; Clark, Peter P.

    1998-12-01

    This paper discusses the optical and opto-mechanical design of a new laser head developed at Polaroid for printing Helios binary film for printing high quality medical hard copy images. The head is part of an external drum printer for 14' X 17' film. The pixel size is 84 X 84 micrometer, produced by four lasers, with the smallest printable spot 3 X 6 micrometer, to produce 4096 gray levels. Two pixels side-by-side are simultaneously printed. The head has eight independent 840 nm diode lasers manufactured by Polaroid. Each laser emits up to 1.1 W over an emission length of about 100 micrometer, with a particularly uniform nearfield irradiance. The lasers are microlensed to equalize the divergences in the two principal meridians. Each packaged laser is aligned in a field-replaceable illuminator whose output beam, focused at infinity, is bore-sighted in a mechanical cylinder. The illuminators are arranged roughly radially. Eight lenses image the laser nearfields on a multi-facet mirror produced by diamond machining. The mirror facets truncate the beams to give the desired pixel shapes and separations. A reducing afocal relay images the mirror onto the film. The final element is a molded aspheric lens, mounted in an actuator to maintain focus on the film. The focusing unit also comprises a triangulation-based focus sensor. The alignment procedures and fixtures were devised concurrently with the head for manufacturing simplicity. The main physical structure is a casting, into which reference surfaces are machined. All optical subassemblies are attached to this casting, with a mixture of optical alignment and self-location. Semi-kinematic cylinder-in-V methodology is utilized. The active alignment steps are done in a sequence that tends to reduce errors from previous steps.

  19. [Bilateral caudate head infarcts].

    PubMed

    Kuriyama, N; Yamamoto, Y; Akiguchi, I; Oiwa, K; Nakajima, K

    1997-11-01

    We reported a 67-year-old woman with bilateral caudate head infarcts. She developed sudden mutism followed by abulia. She was admitted to our hospital 2 months after ictus for further examination. She showed prominent abulia and was inactive, slow and apathetic. Spontaneous activity and speech, immediate response to queries, spontaneous word recall and attention and persistence to complex programs were disturbed. Apparent motor disturbance, gait disturbance, motor aphasia, apraxia and remote memory disturbance were not identified. She seemed to be depressed but not sad. Brain CT and MRI revealed bilateral caudate head hemorrhagic infarcts including bilateral anterior internal capsules, in which the left lesion was more extensive than right one and involved the part of the left putamen. These infarct locations were thought to be supplied by the area around the medial striate artery including Heubner's arteries and the A1 perforator. Digital subtraction angiography showed asymptomatic right internal carotid artery occlusion. She bad had hypertension, diabetes mellitus and atrial fibrillation and also had a left atrium with a large diameter. The infarcts were thought to be caused by cardioembolic occlusion to the distal portion of the left internal carotid artery. Although some variations of vasculature at the anterior communicating artery might contribute to bilateral medial striate artery infarcts, we could not demonstrate such abnormalities by angiography. Bilateral caudate head infarcts involving the anterior internal capsule may cause prominent abulia. The patient did not improve by drug and rehabilitation therapy and died suddenly a year after discharge. PMID:9503974

  20. Orienting head movements resulting from electrical microstimulation of the brainstem tegmentum in the barn owl.

    PubMed

    Masino, T; Knudsen, E I

    1993-01-01

    The size and direction of orienting movements are represented systematically as a motor map in the optic tectum of the barn owl (du Lac and Knudsen, 1990). The optic tectum projects to several distinct regions in the medial brainstem tegmentum, which in turn project to the spinal cord (Masino and Knudsen, 1992). This study explores the hypothesis that a fundamental transformation in the neural representation of orienting movements takes place in the brainstem tegmentum. Head movements evoked by electrical microstimulation in the brainstem tegmentum of the alert barn owl were cataloged and the sites of stimulation were reconstructed histologically. Movements elicited from the brainstem tegmentum were categorized into one of six different classes: saccadic head rotations, head translations, facial movements, vocalizations, limb movements, and twitches. Saccadic head rotations could be further subdivided into two general categories: fixed-direction saccades and goal-directed saccades. Fixed-direction saccades, those whose direction was independent of initial head position, were elicited from the midbrain tegmentum. Goal-directed saccades, those whose direction changed with initial head position, were elicited from the central rhombencephalic reticular formation and from the efferent pathway of the cerebellum. Particular attention was paid to sites from which fixed-direction saccadic movements were elicited, as these movements appeared to represent components of orienting movements. Microstimulation in the medial midbrain tegmentum elicited fixed-direction saccades in one of six directions: rightward, leftward, upward, downward, clockwise roll, and counterclockwise roll. Stimulation in and around the interstitial nucleus of Cajal (InC; a complete list of anatomical abbreviations is given in the Appendix) produced ipsiversive horizontal saccades. Stimulation in the ventral InC and near the dorsal and medial edges of the red nucleus produced upward saccades. Stimulation

  1. Measuring head circumference

    PubMed Central

    Harris, Susan R.

    2015-01-01

    Abstract Objective To provide an evidence-based update emphasizing the importance of measuring head circumference (HC) in infants, with a focus on microcephaly. Quality of evidence PubMed and EMBASE (OvidSP) were searched. Search terms used were head circumference and infants and measurement; microcephaly and infants and measurement; idiopathic microcephaly and infants; and congenital microcephaly and infants. Most of the references for this review were published in 2000 or later. Most evidence is level II. Main message Serial measurement of HC should be incorporated into routine well-child care. Measure the distance around the back of the child’s head with a nonelastic tape measure held above the eyebrows and ears, and plot the measurement on an age- and sex-appropriate growth chart. Microcephaly is HC more than 2 SD below the mean. The most common disability associated with microcephaly is intellectual delay; other common concomitant conditions include epilepsy, cerebral palsy, language delay, strabismus, ophthalmologic disorders, and cardiac, renal, urinary tract, and skeletal anomalies. An interdisciplinary approach to microcephaly is warranted. Although there are no specific interventions to enhance brain growth, dietary or surgical interventions might be helpful in some cases. Infants with microcephaly who show developmental delays might benefit from early intervention programs or developmental physical and occupational therapy. Conclusion Early identification of HC concerns by family physicians can be a critical first step in identifying disorders such as microcephaly, leading to referral to pediatric specialists and, as needed, provision of family-centred early intervention services. PMID:26505062

  2. Active head rotations and eye-head coordination

    NASA Technical Reports Server (NTRS)

    Zangemeister, W. H.; Stark, L.

    1981-01-01

    It is pointed out that head movements play an important role in gaze. The interaction between eye and head movements involves both their shared role in directing gaze and the compensatory vestibular ocular reflex. The dynamics of head trajectories are discussed, taking into account the use of parameterization to obtain the peak velocity, peak accelerations, the times of these extrema, and the duration of the movement. Attention is given to the main sequence, neck muscle EMG and details of the head-movement trajectory, types of head model accelerations, the latency of eye and head movement in coordinated gaze, gaze latency as a function of various factors, and coordinated gaze types. Clinical examples of gaze-plane analysis are considered along with the instantaneous change of compensatory eye movement (CEM) gain, and aspects of variability.

  3. Reactor vessel head permanent shield

    SciTech Connect

    Hankinson, M.F.; Leduc, R.J.; Richard, J.W.; Malandra, L.J.

    1989-05-09

    A nuclear reactor is described comprising: a nuclear reactor pressure vessel closure head; control rod drive mechanisms (CRDMs) disposed within the closure head so as to project vertically above the closure head; cooling air baffle means surrounding the control rod drive mechanisms for defining cooling air paths relative to the control rod drive mechanisms; means defined within the periphery of the closure head for accommodating fastening means for securing the closure head to its associated pressure vessel; lifting lugs fixedly secured to the closure head for facilitating lifting and lowering movements of the closure head relative to the pressure vessel; lift rods respectively operatively associated with the plurality of lifting lugs for transmitting load forces, developed during the lifting and lowering movements of the closure head, to the lifting lugs; upstanding radiation shield means interposed between the cooling air baffle means and the periphery of the enclosure head of shielding maintenance personnel operatively working upon the closure head fastening means from the effects of radiation which may emanate from the control rod drive mechanisms and the cooling air baffle means; and connecting systems respectively associated with each one of the lifting lugs and each one of the lifting rods for connecting each one of the lifting rods to a respective one of each one of the lifting lugs, and for simultaneously connecting a lower end portion of the upstanding radiation shield means to each one of the respective lifting lugs.

  4. S-Glutathionylation of troponin I (fast) increases contractile apparatus Ca2+ sensitivity in fast-twitch muscle fibres of rats and humans

    PubMed Central

    Mollica, J P; Dutka, T L; Merry, T L; Lamboley, C R; McConell, G K; McKenna, M J; Murphy, R M; Lamb, G D

    2012-01-01

    Oxidation can decrease or increase the Ca2+ sensitivity of the contractile apparatus in rodent fast-twitch (type II) skeletal muscle fibres, but the reactions and molecular targets involved are unknown. This study examined whether increased Ca2+ sensitivity is due to S-glutathionylation of particular cysteine residues. Skinned muscle fibres were directly activated in heavily buffered Ca2+ solutions to assess contractile apparatus Ca2+ sensitivity. Rat type II fibres were subjected to S-glutathionylation by successive treatments with 2,2′-dithiodipyridine (DTDP) and glutathione (GSH), and displayed a maximal increase in pCa50 (−log10µCa2+½ at half-maximal force) of ∼0.24 pCa units, with little or no effect on maximum force or Hill coefficient. Partial similar effect was produced by exposure to oxidized gluthathione (GSSG, 10 mm) for 10 min at pH 7.1, and near-maximal effect by GSSG treatment at pH 8.5. None of these treatments significantly altered Ca2+ sensitivity in rat type I fibres. Western blotting showed that both the DTDP–GSH and GSSG–pH 8.5 treatments caused marked S-glutathionylation of the fast troponin I isoform (TnIf) present in type II fibres, but not of troponin C (TnC) or myosin light chain 2. Both the increased Ca2+ sensitivity and glutathionylation of TnIf were blocked by N-ethylmaleimide (NEM). S-Nitrosoglutathione (GSNO) also increased Ca2+ sensitivity, but only in conditions where it caused S-glutathionylation of TnIf. In human type II fibres from vastus lateralis muscle, DTDP–GSH treatment also caused similar increased Ca2+ sensitivity and S-glutathionylation of TnIf. When the slow isoform of TnI in type I fibres of rat was partially substituted (∼30%) with TnIf, DTDP–GSH treatment caused a significant increase in Ca2+ sensitivity (∼0.08 pCa units). TnIf in type II fibres from toad and chicken muscle lack Cys133 present in mammalian TnIf, and such fibres showed no change in Ca2+ sensitivity with DTDP–GSH nor any S

  5. S-glutathionylation of troponin I (fast) increases contractile apparatus Ca2+ sensitivity in fast-twitch muscle fibres of rats and humans.

    PubMed

    Mollica, J P; Dutka, T L; Merry, T L; Lamboley, C R; McConell, G K; McKenna, M J; Murphy, R M; Lamb, G D

    2012-03-15

    Oxidation can decrease or increase the Ca2+ sensitivity of the contractile apparatus in rodent fast-twitch (type II) skeletal muscle fibres, but the reactions and molecular targets involved are unknown. This study examined whether increased Ca2+ sensitivity is due to S-glutathionylation of particular cysteine residues. Skinned muscle fibres were directly activated in heavily buffered Ca2+ solutions to assess contractile apparatus Ca2+ sensitivity. Rat type II fibres were subjected to S-glutathionylation by successive treatments with 2,2′-dithiodipyridine (DTDP) and glutathione (GSH), and displayed a maximal increase in pCa50 (−log10 [Ca2+] at half-maximal force) of ∼0.24 pCa units, with little or no effect on maximum force or Hill coefficient. Partial similar effect was produced by exposure to oxidized gluthathione (GSSG, 10 mM) for 10 min at pH 7.1, and near-maximal effect by GSSG treatment at pH 8.5. None of these treatments significantly altered Ca2+ sensitivity in rat type I fibres. Western blotting showed that both the DTDP–GSH and GSSG–pH 8.5 treatments caused marked S-glutathionylation of the fast troponin I isoform (TnI(f)) present in type II fibres, but not of troponin C (TnC) or myosin light chain 2. Both the increased Ca2+ sensitivity and glutathionylation of TnI(f) were blocked by N-ethylmaleimide (NEM). S-nitrosoglutathione (GSNO) also increased Ca2+ sensitivity, but only in conditions where it caused S-glutathionylation of TnI(f). In human type II fibres from vastus lateralis muscle, DTDP–GSH treatment also caused similar increased Ca2+ sensitivity and S-glutathionylation of TnI(f). When the slow isoform of TnI in type I fibres of rat was partially substituted (∼30%) with TnI(f), DTDP–GSH treatment caused a significant increase in Ca2+ sensitivity (∼0.08 pCa units). TnIf in type II fibres from toad and chicken muscle lack Cys133 present in mammalian TnIf, and such fibres showed no change in Ca2+ sensitivity with DTDP–GSH nor any S

  6. Reactor pressure vessel vented head

    DOEpatents

    Sawabe, J.K.

    1994-01-11

    A head for closing a nuclear reactor pressure vessel shell includes an arcuate dome having an integral head flange which includes a mating surface for sealingly mating with the shell upon assembly therewith. The head flange includes an internal passage extending therethrough with a first port being disposed on the head mating surface. A vent line includes a proximal end disposed in flow communication with the head internal passage, and a distal end disposed in flow communication with the inside of the dome for channeling a fluid therethrough. The vent line is fixedly joined to the dome and is carried therewith when the head is assembled to and disassembled from the shell. 6 figures.

  7. Firing Properties of Rat Lateral Mammillary Single Units: Head Direction, Head Pitch, and Angular Head Velocity

    PubMed Central

    Stackman, Robert W.; Taube, Jeffrey S.

    2006-01-01

    Many neurons in the rat anterodorsal thalamus (ADN) and postsubiculum (PoS) fire selectively when the rat points its head in a specific direction in the horizontal plane, independent of the animal’s location and ongoing behavior. The lateral mammillary nuclei (LMN) are interconnected with both the ADN and PoS and, therefore, are in a pivotal position to influence ADN/PoS neurophysiology. To further understand how the head direction (HD) cell signal is generated, we recorded single neurons from the LMN of freely moving rats. The majority of cells discharged as a function of one of three types of spatial correlates: (1) directional heading, (2) head pitch, or (3) angular head velocity (AHV). LMN HD cells exhibited higher peak firing rates and greater range of directional firing than that of ADN and PoS HD cells. LMN HD cells were modulated by angular head velocity, turning direction, and anticipated the rat’s future HD by a greater amount of time (~95 msec) than that previously reported for ADN HD cells (~25 msec). Most head pitch cells discharged when the rostrocaudal axis of the rat’s head was orthogonal to the horizontal plane. Head pitch cell firing was independent of the rat’s location, directional heading, and its body orientation (i.e., the cell discharged whenever the rat pointed its head up, whether standing on all four limbs or rearing). AHV cells were categorized as fast or slow AHV cells depending on whether their firing rate increased or decreased in proportion to angular head velocity. These data demonstrate that LMN neurons code direction and angular motion of the head in both horizontal and vertical planes and support the hypothesis that the LMN play an important role in processing both egocentric and allocentric spatial information. PMID:9787007

  8. Chryse 'Alien Head'

    NASA Technical Reports Server (NTRS)

    2005-01-01

    26 January 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an impact crater in Chryse Planitia, not too far from the Viking 1 lander site, that to seems to resemble a bug-eyed head. The two odd depressions at the north end of the crater (the 'eyes') may have formed by wind or water erosion. This region has been modified by both processes, with water action occurring in the distant past via floods that poured across western Chryse Planitia from Maja Valles, and wind action common occurrence in more recent history. This crater is located near 22.5oN, 47.9oW. The 150 meter scale bar is about 164 yards long. Sunlight illuminates the scene from the left/lower left.

  9. NASA head sworn in

    NASA Astrophysics Data System (ADS)

    James C. Fletcher was sworn in on May 12, 1986, as administrator of the National Aeronautics and Space Administration (NASA). At a news conference after he was sworn in, Fletcher said that NASA would deal with both its technical problems and its procedural problems before the shuttle will fly again. According to press accounts, he stressed that funds should be made available to replace the Challenger orbiter, which was lost in an explosion on January 28.Fletcher, who had also headed the agency from 1971 to 1977, succeeds James M. Beggs, who was indicted in December 1985 for conspiring to defraud the federal government while serving as a senior executive at the General Dynamics Corporation.

  10. Head of Administration

    NASA Astrophysics Data System (ADS)

    2005-03-01

    Purpose and scope of the position: The main task is to provide efficient administrative services and advice to the Director General, Division Leaders and to staff members in the scientific and technical areas in the fields of financial planning and accounting, personnel management, purchasing, legal and contractual matters, information systems and building and site maintenance. As a member of the ESO Management the Head of Administration contributes essentially to the development of the overall policy, strategic planning, relations to the members of the personnel and maintains professional contacts at highest level outside the Organisation. ESO employs in total approximately 650 staff members and the Administration Division comprises the Administration at the Headquarters in Garching near Munich and the Administration in Santiago (Chile). The successful candidate will be supported by some 50 qualified staff members.

  11. Dual-Head Robotic Welder

    NASA Technical Reports Server (NTRS)

    Beard, Gary S.

    1990-01-01

    Robotic welder uses two welding heads simultaneously. Developed for assembly of "hot dog" shell on main injector for Space Shuttle main engine, concept applicable to other, similarly rounded or contoured workpieces. Opposed heads reduce distortion and stress in opposed weld joints and speed up welding operations.

  12. Kansas: Early Head Start Initiative

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Kansas Early Head Start (KEHS) provides comprehensive services following federal Head Start Program Performance Standards for pregnant women and eligible families with children from birth to age 4. KEHS was implemented in 1998 using Child Care and Development Block Grant (CCDBG) quality set-aside dollars augmented by a transfer of federal…

  13. Cutting Head for Ultrasonic Lithotripsy

    NASA Technical Reports Server (NTRS)

    Angulo, Earl D. (Inventor); Goodfriend, Roger (Inventor)

    1989-01-01

    A cutting head for attachment to the end of the wire probe of an ultrasonic kidney stone disintegration instrument. The cutting head has a plurality of circumferentially arranged teeth formed at one end thereof to provide a cup-shaped receptacle for kidney stones encountered during the disintegration procedure. An integral reduced diameter collar diminishes stress points in the wire and reduces breakage thereof.

  14. Vision Screening For Head Starters.

    ERIC Educational Resources Information Center

    Foley, Celia

    To determine which children in the Head Start program may have vision problems, Head Start teachers and staff do vision "screening." This booklet demonstrates how to do the screening using the Snellen "E Chart." Trouble signs that the test administrator should be aware of are listed, and vision scores are explained simply. Amblyopia is defined,…

  15. Nebraska: Early Head Start Initiative

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Since 1999, Nebraska's Early Head Start Infant/Toddler Quality Initiative has supported Early Head Start (EHS) and community child care partnerships to improve the quality and professionalism of infant and toddler care. EHS programs apply to receive funding to establish partnerships with center-based or home-based child care.The initiative has…

  16. The Acquisition of [Head] Movement.

    ERIC Educational Resources Information Center

    Pye, Clifton

    An analysis of one theory of the acquisition of head movement by children is presented, using longitudinal data from the Mayan language, K'iche'. This theory assumes that children would just require positive evidence of head movement in the input language to instantiate the constructions of their own grammar. The Incorporation Theory addresses the…

  17. Interview with Joe F. Head

    ERIC Educational Resources Information Center

    West, Kim

    2008-01-01

    This article presents an interview with Joe F. Head, Dean of University Admissions and Enrollment Services at Kennesaw State University (KSU) in Georgia, who has more than 35 years of experience in admissions and enrollment services. After completing an M.Ed. in higher education at Georgia Southern University, Head immediately landed a position as…

  18. The Start of Head Start

    ERIC Educational Resources Information Center

    Neugebauer, Roger

    2010-01-01

    The creation of the Head Start program occurred at break-neck speed with many dramatic turns and many colorful players. No one tells the story better than Edward Zigler in "Head Start: The Inside Story of America's Most Successful Educational Experiment"--a detailed and personal, behind the scenes look at the program's inception. From this…

  19. Head Start Impact Study: First Year Findings

    ERIC Educational Resources Information Center

    Puma, Michael; Bell, Stephen; Cook, Ronna; Heid, Camilla; Lopez, Michael

    2005-01-01

    The Congressionally-mandated Head Start Impact Study is being conducted across 84 nationally representative grantee/delegate agencies. Approximately 5,000 newly entering 3- and 4-year-old children applying for Head Start were randomly assigned to either a Head Start group that had access to Head Start program services or to a non-Head Start group…

  20. Stereotactic Body Radiotherapy for Head and Neck Tumors

    ClinicalTrials.gov

    2016-04-18

    Squamous Cell Carcinoma of the Head and Neck; Nasopharyngeal Carcinoma; Salivary Gland Cancer; Head and Neck Sarcoma; Paraganglioma of Head and Neck; Chordoma of Head and Neck; Chondrosarcoma of Head and Neck; Angiofibroma of Head and Neck

  1. Turbidity Current Head Mixing

    NASA Astrophysics Data System (ADS)

    Hernandez, David; Sanchez, Miguel Angel; Medina, Pablo

    2010-05-01

    A laboratory experimental set - up for studying the behaviour of sediment in presence of a turbulent field with zero mean flow is compared with the behaviour of turbidity currents [1] . Particular interest is shown on the initiation of sediment motion and in the sediment lift - off. The behaviour of the turbidity current in a flat ground is compared with the zero mean flow oscilating grid generated turbulence as when wave flow lifts off suspended sediments [2,3]. Some examples of the results obtained with this set-up relating the height of the head of the turbidity current to the equilibrium level of stirred lutoclines are shown. A turbulent velocity u' lower than that estimated by the Shield diagram is required to start sediment motion. The minimum u' required to start sediment lift - off, is a function of sediment size, cohesivity and resting time. The lutocline height depends on u', and the vorticity at the lutocline seems constant for a fixed sediment size [1,3]. Combining grid stirring and turbidty current head shapes analyzed by means of advanced image analysis, sediment vertical fluxes and settling speeds can be measured [4,5]. [1] D. Hernandez Turbulent structure of turbidity currents and sediment transport Ms Thesis ETSECCPB, UPC. Barcelona 2009. [2] A. Sánchez-Arcilla; A. Rodríguez; J.C. Santás; J.M. Redondo; V. Gracia; R. K'Osyan; S. Kuznetsov; C. Mösso. Delta'96 Surf-zone and nearshore measurements at the Ebro Delta. A: International Conference on Coastal Research through large Scale Experiments (Coastal Dynamics '97). University of Plymouth, 1997, p. 186-187. [3] P. Medina, M. A. Sánchez and J. M. Redondo. Grid stirred turbulence: applications to the initiation of sediment motion and lift-off studies Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere. 26, Issue 4, 2001, Pages 299-304 [4] M.O. Bezerra, M. Diez, C. Medeiros, A. Rodriguez, E. Bahia., A. Sanchez-Arcilla and J.M. Redondo. Study on the influence of waves on

  2. Head and Neck Cancer: Symptoms and Signs

    MedlinePlus

    ... Symptoms and Signs Request Permissions Print to PDF Head and Neck Cancer - Symptoms and Signs Approved by the Cancer. ... Cancer Research and Advocacy Survivorship Blog About Us Head and Neck Cancer Guide Cancer.Net Guide Head and Neck ...

  3. Keeping Your Head On Target

    PubMed Central

    Wong, Aaron L.; Zee, David S.; Jinnah, H. A.

    2013-01-01

    The mechanisms by which the human brain controls eye movements are reasonably well understood, but those for the head less so. Here, we show that the mechanisms for keeping the head aimed at a stationary target follow strategies similar to those for holding the eyes steady on stationary targets. Specifically, we applied the neural integrator hypothesis that originally was developed for holding the eyes still in eccentric gaze positions to describe how the head is held still when turned toward an eccentric target. We found that normal humans make head movements consistent with the neural integrator hypothesis, except that additional sensory feedback is needed, from proprioceptors in the neck, to keep the head on target. We also show that the complicated patterns of head movements in patients with cervical dystonia can be predicted by deficits in a neural integrator for head motor control. These results support ideas originally developed from animal studies that suggest fundamental similarities between oculomotor and cephalomotor control, as well as a conceptual framework for cervical dystonia that departs considerably from current clinical views. PMID:23825431

  4. Eye and head motion during head turns in spaceflight

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    Eye-head motion was studied pre-, in- and postflight during single voluntary head turns. A transient increase in vestibulo-ocular reflex (VOR) gain occurred early in the flight, but later trended toward normal. This increased gain was produced by a relative increase in eye counterrotation velocity. Asymmetries in gain with right and left turns also occurred, caused by asymmetries in eye counterrotation velocities. These findings were remarkably similar to those from Soviet primate studies using gaze fixation targets, except the human study trended more rapidly toward normal. These findings differ substantially from those measuring VOR gain by head oscillation, in which no significant changes were found inflight. No visual disturbances were noted in either test condition or in normal activities. These head turn studies are the only ones to date documenting any functional change in VOR in weightlessness.

  5. Cutting Head for Ultrasonic Lithotripsy

    NASA Technical Reports Server (NTRS)

    Angulo, E. D.; Goodfriend, R.

    1987-01-01

    Kidney stones lodged in urinary tract disintegrated with increased safety and efficiency by cutting head attached to end of vibrated wire probe. Aligns probe with stone and enables probe to vibrate long enough to disintegrate stone. Design of cutting head reduces risk of metal-fatigue-induced breakage of probe tip leaving metal fragments in urinary tract. Teeth of cutting head both seat and fragment kidney stone, while extension of collar into catheter lessens mechanical strain in probe wire, increasing probe life and lessening danger of in situ probe breakage.

  6. Topiramate Responsive Exploding Head Syndrome

    PubMed Central

    Palikh, Gaurang M.; Vaughn, Bradley V.

    2010-01-01

    Exploding head syndrome is a rare phenomenon but can be a significant disruption to quality of life. We describe a 39-year-old female with symptoms of a loud bang and buzz at sleep onset for 3 years. EEG monitoring confirmed these events occurred in transition from stage 1 sleep. This patient reported improvement in intensity of events with topiramate medication. Based on these results, topiramate may be an alternative method to reduce the intensity of events in exploding head syndrome. Citation: Palikh GM; Vaughn BV. Topiramate responsive exploding head syndrome. J Clin Sleep Med 2010;6(4):382-383. PMID:20726288

  7. Anaphylaxis Due to Head Injury

    PubMed Central

    Bruner, Heather C.; Bruner, David I.

    2015-01-01

    Both anaphylaxis and head injury are often seen in the emergency department, but they are rarely seen in combination. We present a case of a 30-year-old woman who presented with anaphylaxis with urticaria and angioedema following a minor head injury. The patient responded well to intramuscular epinephrine without further complications or airway compromise. Prior case reports have reported angioedema from hereditary angioedema during dental procedures and maxillofacial surgery, but there have not been any cases of first-time angioedema or anaphylaxis due to head injury. PMID:25987924

  8. Head-Up Tilt.

    PubMed

    Xu, Jinyi; Yang, Lihong; Zhang, Qiang; Li, Shuaibing; Qiao, Zihao; Fang, Ying; Zhao, Guihua; Wang, Qingyi; Liu, Guanghui

    2015-01-01

    Autonomic dysfunction has been associated with paroxysmal atrial fibrillation (PAF). The head-up tilt test (HUTT) is an important diagnostic tool for autonomic dysfunction. The aim of this study was to examine atrial fibrillation recurrence after RFCA by performing HUTT. A total of 488 consecutive patients with PAF who underwent RFCA were prospectively enrolled. HUTT was positive in 154 (31.6%) patients after a mean follow-up of 22.7 ± 3.5 months, and 163 (33.4%) had a recurrence. HUTT positive was significantly higher in PAF patients with recurrence compared to those without (68 (41.7%) versus 86 (26.5%), P < 0.001). Multivariate Cox regression analysis revealed that HUTT positive (HR: 1.96; 95% CI: 1.49-2.48, P < 0.001), left atrial diameter (HR: 1.77; 95%CI: 1.15-2.11, P = 0.004), AF duration (HR: 1.27; 95%CI: 0.98-1.83, P = 0.014), and sleep apnea (HR: 1.02; 95%CI: 0.81-1.53, P = 0.032) were independent predictors of clinical recurrence after RFCA. The success rate of ablation was 70.4% in patients in the HUTT negative group compared with 58.4% in patients in the HUTT positive group (log-rank P = 0.006). Patients with a positive headup tilt test were at an increased risk of AF recurrence after catheter ablation. Our results suggest that HUTT was a significant predictor for AF recurrence after catheter ablation for PAF. PMID:26370369

  9. Preventing head injuries in children

    MedlinePlus

    ... strapped in with the safety harness. Store all firearms and bullets in a locked cabinet. ... of Health and Human Services. Centers for Disease Control and Prevention. Heads up. Facts for physicians about ...

  10. Heater head for stirling engine

    DOEpatents

    Corey, John A.

    1985-07-09

    A monolithic heater head assembly which augments cast fins with ceramic inserts which narrow the flow of combustion gas and obtains high thermal effectiveness with the assembly including an improved flange design which gives greater durability and reduced conduction loss.

  11. Tensile Tests of Round-head, Flat-head, and Brazier-head Rivets

    NASA Technical Reports Server (NTRS)

    Schuette, Evan H; Bartone, Leonard M; Mandel, Merven W

    1944-01-01

    An investigation was conducted to determine the tensile strength of round-head (AN43C), flat-head(AN442), and brazier-head (AN4556) aluminum-alloy rivets because of the scarcity of information on the tensile strength of rivets. The results of the investigation are presented as curves that show the variation of the ratio of the tensile strength of the rivet to the tensile strength of the rivet crank with the ratio of the sheet thickness to the rivet diameter for the different types of rivet.

  12. Indications for ulnar head replacement.

    PubMed

    Berger, Richard A

    2008-08-01

    Implanting an endoprosthesis is a clinically proven means of reestablishing mechanical contact between the distal radius and ulna, thus providing the foundation for stability of the entire forearm. The indications for, contraindications to, and outcomes of ulnar head replacement are discussed, together with the underlying mechanics, pathomechanics of ulnar head excision, the theoretical basis for implant arthroplasty, and the designs that have been employed. PMID:18836608

  13. Cutting head for ultrasonic lithotripsy

    NASA Technical Reports Server (NTRS)

    Anguluo, E. D.; Goodfriend, R. (Inventor)

    1985-01-01

    A cutting head for attachment to the end of the wire probe of an ultrasonic kidney stone disintegration instrument is described. The cutting head has a plurality of circumferentially arranged teeth formed at one end thereof to provide a cup shaped receptacle for kidney stones encountered during the disintegration procedure. An integral reduced diameter collar diminishes stress points in the wire and reduce breakage thereof.

  14. Ghost Head Nebula

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Looking like a colorful holiday card, a new image from NASA's Hubble Space Telescope reveals a vibrant green and red nebula far from Earth.

    The image of NGC 2080, taken by Hubble's Wide Field and Planetary Camera 2, designed and built by NASA's Jet Propulsion Laboratory, Pasadena, Calif., is available online at http://www.jpl.nasa.gov/images/wfpc . Images like this help astronomers investigate star formation in nebulas.

    NGC 2080, nicknamed 'The Ghost Head Nebula,' is one of a chain of star-forming regions lying south of the 30 Doradus nebula in the Large Magellanic Cloud. 30 Doradus is the largest star-forming complex in the local group of galaxies. This 'enhanced color' picture is composed of three narrow-band-filter images obtained by Hubble on March 28, 2000.

    The red and blue light come from regions of hydrogen gas heated by nearby stars. The green light on the left comes from glowing oxygen. The energy to illuminate the green light is supplied by a powerful stellar wind, a stream of high-speed particles coming from a massive star just outside the image. The central white region is a combination of all three emissions and indicates a core of hot, massive stars in this star-formation region. Intense emission from these stars has carved a bowl-shaped cavity in surrounding gas.

    In the white region, the two bright areas (the 'eyes of the ghost') - named A1 (left) and A2 (right) -- are very hot, glowing 'blobs' of hydrogen and oxygen. The bubble in A1 is produced by the hot, intense radiation and powerful stellar wind from one massive star. A2 contains more dust and several hidden, massive stars. The massive stars in A1 and A2 must have formed within the last 10,000 years, since their natal gas shrouds are not yet disrupted by the powerful radiation of the newborn stars.

    The Space Telescope Science Institute is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract with the Goddard Space Flight Center

  15. 29 CFR 1917.93 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Head protection. 1917.93 Section 1917.93 Labor Regulations...) MARINE TERMINALS Personal Protection § 1917.93 Head protection. (a) The employer shall ensure that each... the head from falling objects. (b)(1) The employer must ensure that head protection complies with...

  16. 29 CFR 1917.93 - Head protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Head protection. 1917.93 Section 1917.93 Labor Regulations...) MARINE TERMINALS Personal Protection § 1917.93 Head protection. (a) The employer shall ensure that each... the head from falling objects. (b)(1) The employer must ensure that head protection complies with...

  17. 29 CFR 1926.100 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Head protection. 1926.100 Section 1926.100 Labor... § 1926.100 Head protection. (a) Employees working in areas where there is a possible danger of head... Institute, Z89.1-1969, Safety Requirements for Industrial Head Protection. (c) Helmets for the...

  18. 29 CFR 1917.93 - Head protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Head protection. 1917.93 Section 1917.93 Labor Regulations...) MARINE TERMINALS Personal Protection § 1917.93 Head protection. (a) The employer shall ensure that each... the head from falling objects. (b)(1) The employer must ensure that head protection complies with...

  19. 29 CFR 1917.93 - Head protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Head protection. 1917.93 Section 1917.93 Labor Regulations...) MARINE TERMINALS Personal Protection § 1917.93 Head protection. (a) The employer shall ensure that each... the head from falling objects. (b)(1) The employer must ensure that head protection complies with...

  20. 29 CFR 1917.93 - Head protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Head protection. 1917.93 Section 1917.93 Labor Regulations...) MARINE TERMINALS Personal Protection § 1917.93 Head protection. (a) The employer shall ensure that each... the head from falling objects. (b)(1) The employer must ensure that head protection complies with...

  1. Communicating printed headings to the ear.

    PubMed

    Lorch, Robert F; Chen, Hung-Tao; Jawahir, Aqeel A; Lemarié, Julie

    2016-05-01

    Two experiments compared three methods of translating printed headings into an auditory format. In both experiments, college students listened to a text with instructions to stop the recording whenever they heard a heading and type the hierarchical level and exact wording of the heading. Listeners were poor at identifying headings and their levels if the headings were not distinguished from the rest of the text. However, listeners were very good at identifying headings if any method of signalling was used to distinguish headings and communicate their hierarchical level. The methods included: (1) tones preceding headings, (2) changes of speaker to indicate headings or (3) verbal labels preceding headings. Although all three signalling methods improved identification of a heading's hierarchical level, the labelling method was the most effective means of communicating hierarchical level. Thus, the study identifies a simple method of effectively communicating headings in spoken text. Practitioner Summary: The study attempted to identify effective ways of communicating heading information in spoken text. College students listened to texts in order to detect headings and record their wording and hierarchical level. Performance was excellent when headings were preceded by verbal phrases that signalled the upcoming headings and their levels. PMID:27267653

  2. The perception of heading during eye movements

    NASA Technical Reports Server (NTRS)

    Royden, Constance S.; Banks, Martin S.; Crowell, James A.

    1992-01-01

    Warren and Hannon (1988, 1990), while studying the perception of heading during eye movements, concluded that people do not require extraretinal information to judge heading with eye/head movements present. Here, heading judgments are examined at higher, more typical eye movement velocities than the extremely slow tracking eye movements used by Warren and Hannon. It is found that people require extraretinal information about eye position to perceive heading accurately under many viewing conditions.

  3. [Bobble-head doll syndrome].

    PubMed

    Roubergue, A; Beauvais, P; Richardet, J M

    1985-05-01

    A new case of Bobble-head doll syndrome with aqueductal stenosis is presented in a 14 year-old boy. Ventriculocisternostomy performed 8 years after the onset of the abnormal movement resulted in moderate reduction of the head bobbling. Twenty-two cases were found in a review of the literature. In all cases there was a chronic slowly progressive hydrocephalus with usually a cyst of the third ventricle; aqueductal stenosis was less frequent. When recorded, psychomotor development was impaired. Treatment is neurosurgical. Pathogenesis remains unknown. PMID:4074089

  4. Rotary head type reproducing apparatus

    DOEpatents

    Takayama, Nobutoshi; Edakubo, Hiroo; Kozuki, Susumu; Takei, Masahiro; Nagasawa, Kenichi

    1986-01-01

    In an apparatus of the kind arranged to reproduce, with a plurality of rotary heads, an information signal from a record bearing medium having many recording tracks which are parallel to each other with the information signal recorded therein and with a plurality of different pilot signals of different frequencies also recorded one by one, one in each of the recording tracks, a plurality of different reference signals of different frequencies are simultaneously generated. A tracking error is detected by using the different reference signals together with the pilot signals which are included in signals reproduced from the plurality of rotary heads.

  5. Variation in natural head position and establishing corrected head position.

    PubMed

    Barbera, A L; Sampson, W J; Townsend, G C

    2014-06-01

    Corrected head position (CHP) has been simulated by using the Frankfurt horizontal (FH) for over 100 years but FH varies between individuals. Because CHP is biologically relevant for orthodontic diagnosis and treatment planning, orthognathic surgical planning, and art, this study examined relationships between head position and selected cephalometric planes. Natural head position cephalograms of Aboriginal Australians and two contemporary samples from private orthodontic practices were analysed. Each sample comprised 40 individuals (20 males and 20 females). The Aboriginal Australian sample comprised longitudinal data (T1 early adolescent, T2 late adolescent, and T3 adult), enabling examination of natural head position (NHP) reproducibility over a period of approximately 8 years. Results of reproducibility differences revealed an absolute mean=2.9°, range=-7.9° to 8.2°, and standard deviation=3.6°. Stable basicranial line (SBL), neutral horizontal axis (NHA), FH, palatal plane (P plane), and Krogman-Walker plane (KW plane) demonstrated near parallelism and their mean angulations from the true horizontal (HOR) ranged between -4.6° and 2.4°. While NHP is not consistently reproducible at the individual level, the combined use of multiple planes such as SBL, P plane, and KW plane enables a more consistent CHP to be achieved. PMID:24785580

  6. Head kinematics during shaking associated with abusive head trauma.

    PubMed

    Lintern, T O; Puhulwelle Gamage, N T; Bloomfield, F H; Kelly, P; Finch, M C; Taberner, A J; Nash, M P; Nielsen, P M F

    2015-09-18

    Abusive head trauma (AHT) is a potentially fatal result of child abuse but the mechanisms of injury are controversial. To address the hypothesis that shaking alone is sufficient to elicit the injuries observed, effective computational and experimental models are necessary. This paper investigates the use of a coupled rigid-body computational modelling framework to reproduce in vivo shaking kinematics in AHT. A sagittal plane OpenSim computational model of a lamb was developed and used to interpret biomechanical data from in vivo shaking experiments. The acceleration of the head during shaking was used to provide in vivo validation of the associated computational model. Results of this study demonstrated that peak accelerations occurred when the head impacted the torso and produced acceleration magnitudes exceeding 200ms(-)(2). The computational model demonstrated good agreement with the experimental measurements and was shown to be able to reproduce the high accelerations that occur during impact. The biomechanical results obtained with the computational model demonstrate the utility of using a coupled rigid-body modelling framework to describe infant head kinematics in AHT. PMID:26256822

  7. The Longest Run of Heads.

    ERIC Educational Resources Information Center

    Schilling, Mark F.

    1990-01-01

    Developed are simple recursion formulas for generating the exact distribution of the longest run of heads, both for a fair coin and for a biased coin. Discusses the applications of runs-related phenomena such as molecular biology, Markov chains, geometric variables, and random variables. (YP)

  8. Graham confirmed as OSTP Head

    NASA Astrophysics Data System (ADS)

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

  9. HANDBOOK FOR PROJECT HEAD START.

    ERIC Educational Resources Information Center

    GRAHAM, JORY

    THIS BOOKLET WAS DESIGNED TO MEET SOME IMMEDIATE NEEDS FOR THE FIRST SUMMER SESSION OF PROJECT HEAD START. IT CONTAINS SOME OF THE MOST WORKABLE AND PROMISING TEACHING METHODS IN THE ENTIRE FIELD OF COMPENSATORY EDUCATIONS, METHODS THAT HAVE BEEN USED IN PRIVATELY SPONSORED CENTERS AND HAVE PROVED VALUABLE IN COPING WITH PROBLEMS ENCOUNTERED IN…

  10. Femoral head cartilage disarticulation disorder

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Femoral head cartilage disarticulation disorder and necrosis is a major skeletal problem in broiler breeders since they are maintained for a long time in the farm. The etiology of this disease is not well understood. A field study was conducted to understand the basis of this metabolic disease. Six ...

  11. Head Start Planned Variation Program.

    ERIC Educational Resources Information Center

    Klein, Jenny

    There is little agreement concerning which methods of preschool intervention are most effective. In order to evaluate several approaches to early childhood education, Project Head Start, in conjunction with Project Follow Through, has initiated the Planned Variation program. This year only a pilot project is underway with eight schools…

  12. Head Start Dental Health Curriculum.

    ERIC Educational Resources Information Center

    Administration for Children, Youth, and Families (DHHS), Washington, DC. Head Start Bureau.

    This curriculum for Head Start programs provides preschool learning experiences that teach about dental health. The majority of the curriculum guide is devoted to the following lesson plans: (1) "Introduction of 'Smiley the Super Pup'," an optional puppet character which may be used to review the concepts covered in each lesson; (2) "Visiting the…

  13. Neuroelectromagnetic Forward Head Modeling Toolbox

    PubMed Central

    Acar, Zeynep Akalin; Makeig, Scott

    2014-01-01

    This paper introduces a Neuroelectromagnetic Forward Head Modeling Toolbox (NFT) running under MATLAB (The Mathworks, Inc.) for generating realistic head models from available data (MRI and/or electrode locations) and for computing numerical solutions for the forward problem of electromagnetic source imaging. The NFT includes tools for segmenting scalp, skull, cerebrospinal fluid (CSF) and brain tissues from T1-weighted magnetic resonance (MR) images. The Boundary Element Method (BEM) is used for the numerical solution of the forward problem. After extracting segmented tissue volumes, surface BEM meshes can be generated. When a subject MR image is not available, a template head model can be warped to measured electrode locations to obtain an individualized head model. Toolbox functions may be called either from a graphic user interface compatible with EEGLAB (http://sccn.ucsd.edu/eeglab), or from the MATLAB command line. Function help messages and a user tutorial are included. The toolbox is freely available under the GNU Public License for noncommercial use and open source development. PMID:20457183

  14. Model of beam head erosion

    SciTech Connect

    Lee, E.P.

    1980-08-08

    An analytical model of beam head dynamics is presented, leading to an estimate of the erosion rate due to the combined effects of Ohmic dissipation and scattering. Agreement with the results of a computer simulation and detailed one-dimensional computations is good in all respects except for the scaling of the erosion rate with net current.

  15. Head nurse or hotel manager?

    PubMed

    McAlvanah, M

    1989-01-01

    The responsibility of making room assignments for patients can be both a challenging and frustrating experience for a head nurse. Many factors must be considered when making room assignments while consumer dissatisfaction with the process must be handled creatively and with understanding. PMID:2734042

  16. Head banging in young children.

    PubMed

    Vinson, R P; Gelinas-Sorell, D F

    1991-05-01

    Head banging is a rhythmic motor activity that may occur in normal infants and young children, as well as in children with underlying psychiatric or neurologic disease. Once underlying pathology has been excluded, parents should be reassured about the benign nature of the activity. PMID:2021098

  17. Hurricane Rina Headed to Mexico

    NASA Video Gallery

    An animation of NOAA GOES-13 satellite observations from October 23 at 2:45 p.m. EDT through Oct. 25 at 1:30 p.m. EDT shows a strengthening Hurricane Rina in the western Caribbean Sea and headed fo...

  18. Drugs Approved for Head and Neck Cancer

    MedlinePlus

    ... Professionals Questions to Ask about Your Treatment Research Drugs Approved for Head and Neck Cancer This page ... and neck cancer that are not listed here. Drugs Approved for Head and Neck Cancer Abitrexate (Methotrexate) ...

  19. Adjustment of saccade characteristics during head movements.

    NASA Technical Reports Server (NTRS)

    Morasso, P.; Bizzi, E.; Dichgans, J.

    1973-01-01

    Saccade characteristics have been studied during coordinated eye-head movements in monkeys. Amplitude, duration, and peak velocity of saccades with head turning were compared with saccades executed while the head was artificially restrained. The results indicate that the saccade characteristics are modulated as a function of head movement, hence the gaze movement (eye+head) exactly matches saccades with head fixed. Saccade modulation is achieved by way of negative vestibulo-ocular feedback. The neck proprioceptors, because of their longer latency, are effective only if the head starts moving prior to the onset of saccade. It is concluded that saccades make with head turning are not 'ballistic' movements because their trajectory is not entirely predetermined by a central command.

  20. Head Start on Science Preliminary Findings.

    ERIC Educational Resources Information Center

    Ritz, William C.; Von Blum, Ruth

    For many Head Start teachers and staff, the word "science" conjures up uncomfortable feelings and memories. The purpose of this project--a collaborative effort of California State University, Long Beach and the Head Start Program of Long Beach Unified School District (LBUSD)--was to prepare Head Start staff to become more capable, comfortable,…

  1. Effects of Headings on Text Processing.

    ERIC Educational Resources Information Center

    Brooks, Larry W.; And Others

    1983-01-01

    Two experiments examined the effects of embedded and intact (outline) headings on the processing of complex text material by college students. Results indicated that embedded headings reliably improved delayed test performance. It was further found that instructions in the use of headings as processing aids facilitated test performance. (Author/PN)

  2. 29 CFR 1910.135 - Head protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 5 2011-07-01 2011-07-01 false Head protection. 1910.135 Section 1910.135 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Personal Protective Equipment § 1910.135 Head protection. (a) General... in areas where there is a potential for injury to the head from falling objects. (2) The...

  3. 29 CFR 1915.155 - Head protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Head protection. 1915.155 Section 1915.155 Labor... (PPE) § 1915.155 Head protection. (a) Use. (1) The employer shall ensure that each affected employee wears a protective helmet when working in areas where there is a potential for injury to the head...

  4. 33 CFR 142.30 - Head protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Head protection. 142.30 Section... CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.30 Head... conductors shall wear a head protector meeting the specifications of ANSI Z89.1, for the hazard involved....

  5. 29 CFR 1915.155 - Head protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Head protection. 1915.155 Section 1915.155 Labor... (PPE) § 1915.155 Head protection. (a) Use. (1) The employer shall ensure that each affected employee wears a protective helmet when working in areas where there is a potential for injury to the head...

  6. 33 CFR 142.30 - Head protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Head protection. 142.30 Section... CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.30 Head... conductors shall wear a head protector meeting the specifications of ANSI Z89.1, for the hazard involved....

  7. 49 CFR 572.16 - Head.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Head. 572.16 Section 572.16 Transportation Other... OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 3-Year-Old Child § 572.16 Head. (a) The head consists of the assembly designated as SA 103C 010 on drawing No. SA 103C 001, and conforms...

  8. 29 CFR 1918.103 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Head protection. 1918.103 Section 1918.103 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Personal Protective Equipment § 1918.103 Head... in areas where there is a potential for injury to the head from falling objects. (b)(1) The...

  9. 29 CFR 1910.135 - Head protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 5 2014-07-01 2014-07-01 false Head protection. 1910.135 Section 1910.135 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Personal Protective Equipment § 1910.135 Head protection. (a) General... in areas where there is a potential for injury to the head from falling objects. (2) The...

  10. 49 CFR 572.16 - Head.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Head. 572.16 Section 572.16 Transportation Other... OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 3-Year-Old Child § 572.16 Head. (a) The head consists of the assembly designated as SA 103C 010 on drawing No. SA 103C 001, and conforms...

  11. 31 CFR 0.106 - Bureau Heads.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... explanation of the applicable post-employment restrictions contained in 18 U.S.C. 207 and 5 CFR part 2641 and... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Bureau Heads. 0.106 Section 0.106... RULES OF CONDUCT General Provisions Responsibilities § 0.106 Bureau Heads. Bureau heads or designees...

  12. 29 CFR 1910.135 - Head protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 5 2012-07-01 2012-07-01 false Head protection. 1910.135 Section 1910.135 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Personal Protective Equipment § 1910.135 Head protection. (a) General... in areas where there is a potential for injury to the head from falling objects. (2) The...

  13. 29 CFR 1918.103 - Head protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Head protection. 1918.103 Section 1918.103 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Personal Protective Equipment § 1918.103 Head... in areas where there is a potential for injury to the head from falling objects. (b)(1) The...

  14. 33 CFR 142.30 - Head protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Head protection. 142.30 Section... CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.30 Head... conductors shall wear a head protector meeting the specifications of ANSI Z89.1, for the hazard involved....

  15. 29 CFR 1915.155 - Head protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Head protection. 1915.155 Section 1915.155 Labor... (PPE) § 1915.155 Head protection. (a) Use. (1) The employer shall ensure that each affected employee wears a protective helmet when working in areas where there is a potential for injury to the head...

  16. 29 CFR 1915.155 - Head protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Head protection. 1915.155 Section 1915.155 Labor... (PPE) § 1915.155 Head protection. (a) Use. (1) The employer shall ensure that each affected employee wears a protective helmet when working in areas where there is a potential for injury to the head...

  17. 29 CFR 1918.103 - Head protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Head protection. 1918.103 Section 1918.103 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Personal Protective Equipment § 1918.103 Head... in areas where there is a potential for injury to the head from falling objects. (b)(1) The...

  18. 33 CFR 142.30 - Head protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Head protection. 142.30 Section... CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.30 Head... conductors shall wear a head protector meeting the specifications of ANSI Z89.1, for the hazard involved....

  19. 29 CFR 1918.103 - Head protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Head protection. 1918.103 Section 1918.103 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Personal Protective Equipment § 1918.103 Head... in areas where there is a potential for injury to the head from falling objects. (b)(1) The...

  20. 29 CFR 1910.135 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Head protection. 1910.135 Section 1910.135 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Personal Protective Equipment § 1910.135 Head protection. (a) General... in areas where there is a potential for injury to the head from falling objects. (2) The...

  1. 29 CFR 1915.155 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Head protection. 1915.155 Section 1915.155 Labor... (PPE) § 1915.155 Head protection. (a) Use. (1) The employer shall ensure that each affected employee wears a protective helmet when working in areas where there is a potential for injury to the head...

  2. 29 CFR 1910.135 - Head protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 5 2013-07-01 2013-07-01 false Head protection. 1910.135 Section 1910.135 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Personal Protective Equipment § 1910.135 Head protection. (a) General... in areas where there is a potential for injury to the head from falling objects. (2) The...

  3. 29 CFR 1918.103 - Head protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Head protection. 1918.103 Section 1918.103 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Personal Protective Equipment § 1918.103 Head... in areas where there is a potential for injury to the head from falling objects. (b)(1) The...

  4. HISTOLOGY AND PHYSIOLOGY OF FUSARIUM HEAD BLIGHT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium head blight re-emerged as a devastating disease of wheat and barley in the 1990s in the midwestern U.S. Research efforts to control the disease have been hampered by limited knowledge of how the fungal head blight pathogens infect and damage head tissue and what natural defenses the plant h...

  5. Combustor with non-circular head end

    SciTech Connect

    Kim, Won -Wook; McMahan, Kevin Weston

    2015-09-29

    The present application provides a combustor for use with a gas turbine engine. The combustor may include a head end with a non-circular configuration, a number of fuel nozzles positioned about the head end, and a transition piece extending downstream of the head end.

  6. Dimensions of Family Coping with Head Injury.

    ERIC Educational Resources Information Center

    Kosciulek, John F.

    1994-01-01

    Examined dimensions underlying family coping with head injury. Data from 150 families with a member with a head injury identified 3 dimensions of coping: individual-to-family versus family-to-community coping; family-respite versus head-injury-focused coping; and cognitive versus behavioral coping. Findings have implications for family stress and…

  7. [The bobble head doll syndrome].

    PubMed

    Notholt-Heerich, B; Körholz, D; Voit, T; Lumenta, C

    1987-01-01

    A 4,1 year old girl with bobble head doll syndrome is described. The child showed the typical 2-3 per second anterior-posterior movements of the head. The girl had a retarded motor development and retarded growth. On CT scan we found a cyst within the third ventricle and a hydrocephalus of the lateral ventricles. To reduce the hydrocephalus we implanted a ventricular-cardial low pressure shunt system. Repeated emptying of the cyst via an Ommaya reservoir had no long-term effect. Implantation of a cysto-peritoneal shunt-system led to a reduction of the cyst (determined by CT scan) and an improvement of the symptoms. PMID:3586562

  8. Low cutter load raise head

    SciTech Connect

    Saxman, W.C.

    1981-03-31

    A raise head having a multiplicity of cutters for enlarging a pilot hole into a larger diameter hole by disintegrating the earth formations that surround the pilot hole is provided that will require lower cutter loads to penetrate the formations being bored by directing the rock fracture planes toward the pilot hole forcing the rock to yield with less input energy. The cutters are positioned on the raise head to provide an earth formation contact profile with a major portion of said earth formation contact profile extending outward and upward from said pilot hole. The included angle between the major portion of the earth formation contact profile and the axis of the pilot hole is less than 90/sup 0/.

  9. Head Resistance Due to Radiators

    NASA Technical Reports Server (NTRS)

    Kleinschmidt, R V; Parsons, S R

    1920-01-01

    Part 1 deals with the head resistance of a number of common types of radiator cores at different speeds in free air, as measured in the wind tunnel at the bureau of standards. This work was undertaken to determine the characteristics of various types of radiator cores, and in particular to develop the best type of radiator for airplanes. Some 25 specimens of core were tested, including practically all the general types now in use, except the flat plate type. Part 2 gives the results of wind tunnel tests of resistance on a model fuselage with a nose radiator. Part 3 presents the results of preliminary tests of head resistance of a radiator enclosed in a streamlined casing. Special attention is given to the value of wing radiator and of the radiator located in the open, especially when it is provided with a properly designed streamlined casing.

  10. Sealed head access area enclosure

    DOEpatents

    Golden, Martin P.; Govi, Aldo R.

    1978-01-01

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

  11. Family Connections: Helping Early Head Start/Head Start Staff and Parents Address Mental Health Challenges

    ERIC Educational Resources Information Center

    Beardslee, William R.; Avery, Mary Watson; Ayoub, Catherine; Watts, Caroline L.

    2009-01-01

    Early Head Start/Head Start teachers and staff encounter parents who have wrestled with depression and other adversities every day. This article describes an innovative program of trainings for and consultation to Early Head Start/Head Start staff to help them effectively deal with mental heath challenges faced by parents and children. The program…

  12. Hot gas engine heater head

    DOEpatents

    Berntell, John O.

    1983-01-01

    A heater head for a multi-cylinder double acting hot gas engine in which each cylinder is surrounded by an annular regenerator unit, and in which the tops of each cylinder and its surrounding regenerator are interconnected by a multiplicity of heater tubes. A manifold for the heater tubes has a centrally disposed duct connected to the top of the cylinder and surrounded by a wider duct connecting the other ends of the heater tubes with the regenerator unit.

  13. ACR Appropriateness Criteria Head Trauma.

    PubMed

    Shetty, Vilaas S; Reis, Martin N; Aulino, Joseph M; Berger, Kevin L; Broder, Joshua; Choudhri, Asim F; Kendi, A Tuba; Kessler, Marcus M; Kirsch, Claudia F; Luttrull, Michael D; Mechtler, Laszlo L; Prall, J Adair; Raksin, Patricia B; Roth, Christopher J; Sharma, Aseem; West, O Clark; Wintermark, Max; Cornelius, Rebecca S; Bykowski, Julie

    2016-06-01

    Neuroimaging plays an important role in the management of head trauma. Several guidelines have been published for identifying which patients can avoid neuroimaging. Noncontrast head CT is the most appropriate initial examination in patients with minor or mild acute closed head injury who require neuroimaging as well as patients with moderate to severe acute closed head injury. In short-term follow-up neuroimaging of acute traumatic brain injury, CT and MRI may have complementary roles. In subacute to chronic traumatic brain injury, MRI is the most appropriate initial examination, though CT may have a complementary role in select circumstances. Advanced neuroimaging techniques are areas of active research but are not considered routine clinical practice at this time. In suspected intracranial vascular injury, CT angiography or venography or MR angiography or venography is the most appropriate imaging study. In suspected posttraumatic cerebrospinal fluid leak, high-resolution noncontrast skull base CT is the most appropriate initial imaging study to identify the source, with cisternography reserved for problem solving. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. PMID:27262056

  14. Five-Channel Polychromator Head

    NASA Technical Reports Server (NTRS)

    Eskridge, Richard; Dobson, Chris; Lee, Mike; Robertson, Tony

    1995-01-01

    Five-channel polychromator head samples Raman-scattering spectrum simultaneously at five wavelengths. Each channel consists of 1-mm fiber-optic cable that is individually translatable along dispersion axis of spectrometer to provide both flexibility and fine-tuning capability. Laser raman thermometer not thermometer in usual sense of word, but noncontact spectrometer that measures temperature indirectly in terms of relative intensities of selected Raman-scattering spectral lines.

  15. Arthroplasty in Femoral Head Osteonecrosis

    PubMed Central

    Nam, Dong Cheol; Jung, Kwangyoung

    2014-01-01

    Osteonecrosis of the femoral head is a destructive joint disease requiring early hip arthroplasty. The polyethylene-metal design using a 22-mm femoral head component, introduced by Charnley in 1950, has been widely used for over half a century. Since then, different materials with the capacity to minimize friction between bearing surfaces and various cement or cementless insert fixations have been developed. Although the outcome of second and third generation designs using better bearing materials and technologies has been favorable, less favorable results are seen with total hip arthroplasty in young patients with osteonecrosis. Selection of appropriate materials for hip arthroplasty is important for any potential revisions that might become inevitable due to the limited durability of a prosthetic hip joint. Alternative hip arthroplasties, which include hemiresurfacing arthroplasty and bipolar hemiarthroplasty, have not been found to have acceptable outcomes. Metal-on-metal resurfacing has recently been suggested as a feasible option for young patients with extra physical demands; however, concerns about complications such as hypersensitivity reaction or pseudotumor formation on metal bearings have emerged. To ensure successful long-term outcomes in hip arthroplasty, factors such as insert stabilization and surfaces with less friction are essential. Understanding these aspects in arthroplasty is important to selection of proper materials and to making appropriate decisions for patients with osteonecrosis of the femoral head. PMID:27536561

  16. Head Start Oral Health Assessment.

    PubMed

    Reed, Rebecca; York, Jill; Dady, Nadege; Chaviano-Moran, Rosa; Jiang, Shuying; Holtzman, Joseph

    2016-05-01

    Purpose A Head Start program located in Paterson, New Jersey considered establishing a school-based dental clinic to address unmet oral health needs such as access to care and the need for restorative treatment. The purpose of this study was to establish the oral health status of Head Start children, their treatment needs, and parents' interest and willingness to utilize a school-based dental clinic. Description School-based dental care has been used to address access to care issues, particularly among children who live in underserved areas. A 21 item survey was used to correlate the results of an oral exam performed on the Head Start children and the parents' preferences, beliefs and access patterns. Fisher's exact test and Chi squared test were used to study the association among variable with significance levels set at 0.05. Assessment The oral exam revealed a high caries rate amongst all of the children. Parental responses indicated strong support for the establishment of a school-based clinic and identified the need for further parental education. Having a regular source of care was found to be unrelated to treatment needs. Conclusion Further education of the parents regarding the child's oral health is critical to the success and viability of this school-based clinic. PMID:27017227

  17. Animal Models of Head Trauma

    PubMed Central

    Cernak, Ibolja

    2005-01-01

    Summary: Animal models of traumatic brain injury (TBI) are used to elucidate primary and secondary sequelae underlying human head injury in an effort to identify potential neuroprotective therapies for developing and adult brains. The choice of experimental model depends upon both the research goal and underlying objectives. The intrinsic ability to study injury-induced changes in behavior, physiology, metabolism, the blood/tissue interface, the blood brain barrier, and/or inflammatory- and immune-mediated responses, makes in vivo TBI models essential for neurotrauma research. Whereas human TBI is a highly complex multifactorial disorder, animal trauma models tend to replicate only single factors involved in the pathobiology of head injury using genetically well-defined inbred animals of a single sex. Although such an experimental approach is helpful to delineate key injury mechanisms, the simplicity and hence inability of animal models to reflect the complexity of clinical head injury may underlie the discrepancy between preclinical and clinical trials of neuroprotective therapeutics. Thus, a search continues for new animal models, which would more closely mimic the highly heterogeneous nature of human TBI, and address key factors in treatment optimization. PMID:16389305

  18. Porcine Head Response to Blast

    PubMed Central

    Shridharani, Jay K.; Wood, Garrett W.; Panzer, Matthew B.; Capehart, Bruce P.; Nyein, Michelle K.; Radovitzky, Raul A.; Bass, Cameron R. ‘Dale’

    2012-01-01

    Recent studies have shown an increase in the frequency of traumatic brain injuries related to blast exposure. However, the mechanisms that cause blast neurotrauma are unknown. Blast neurotrauma research using computational models has been one method to elucidate that response of the brain in blast, and to identify possible mechanical correlates of injury. However, model validation against experimental data is required to ensure that the model output is representative of in vivo biomechanical response. This study exposes porcine subjects to primary blast overpressures generated using a compressed-gas shock tube. Shock tube blasts were directed to the unprotected head of each animal while the lungs and thorax were protected using ballistic protective vests similar to those employed in theater. The test conditions ranged from 110 to 740 kPa peak incident overpressure with scaled durations from 1.3 to 6.9 ms and correspond approximately with a 50% injury risk for brain bleeding and apnea in a ferret model scaled to porcine exposure. Instrumentation was placed on the porcine head to measure bulk acceleration, pressure at the surface of the head, and pressure inside the cranial cavity. Immediately after the blast, 5 of the 20 animals tested were apneic. Three subjects recovered without intervention within 30 s and the remaining two recovered within 8 min following respiratory assistance and administration of the respiratory stimulant doxapram. Gross examination of the brain revealed no indication of bleeding. Intracranial pressures ranged from 80 to 390 kPa as a result of the blast and were notably lower than the shock tube reflected pressures of 300–2830 kPa, indicating pressure attenuation by the skull up to a factor of 8.4. Peak head accelerations were measured from 385 to 3845 G’s and were well correlated with peak incident overpressure (R2 = 0.90). One SD corridors for the surface pressure, intracranial pressure (ICP), and head acceleration are

  19. Effects of vestibular loss on head stabilization in response to head and body perturbations

    NASA Technical Reports Server (NTRS)

    Shupert, C. L.; Horak, F. B.; Peterson, B. W. (Principal Investigator)

    1996-01-01

    Control of head position during postural responses is important to facilitate both the interpretation of vestibular signals and the stabilization of gaze. In these experiments, we compared head stabilization for two different postural tasks: 1) in response to perturbations at the head, and 2) in response to perturbations induced at the support surface, which perturb both body and head position. To determine whether normal vestibular function is necessary for head stabilization in these two tasks, responses to forward and backward mechanical perturbations of the head and body were compared for 13 normal subjects and 4 patients with profound bilateral vestibular loss (two with vestibular loss in adulthood and two in infancy). Normal subjects showed little neck muscle activity for body perturbations, but large, early activations in both neck extensors and flexors for head perturbations. In contrast, vestibular patients showed excessive neck muscle activation for body perturbations and reduced or absent neck muscle activity for head perturbations. Patients with vestibular loss in adulthood also showed increased head acceleration in response to both head and body perturbations, but patients with vestibular loss in infancy showed more normal head accelerations. For body perturbations, the differences in head acceleration between patients and normals were greater for later head acceleration peaks, indicating poor head control during the execution of the postural response. Trunk angle changes were also higher in the patients for forward body perturbations, indicating that poorer control of trunk position could have contributed to their poorer head stabilization. These results indicate that the vestibular system plays an important role in head and trunk stabilization for both head and body perturbations. However, the more normal head accelerations of the patients with infant vestibular loss also indicate that other mechanisms, possibly involving neck reflexes, can at least

  20. Head position modulates optokinetic nystagmus.

    PubMed

    Pettorossi, V E; Ferraresi, A; Botti, F M; Panichi, R; Barmack, N H

    2011-08-01

    Orientation and movement relies on both visual and vestibular information mapped in separate coordinate systems. Here, we examine how coordinate systems interact to guide eye movements of rabbits. We exposed rabbits to continuous horizontal optokinetic stimulation (HOKS) at 5°/s to evoke horizontal eye movements, while they were statically or dynamically roll-tilted about the longitudinal axis. During monocular or binocular HOKS, when the rabbit was roll-tilted 30° onto the side of the eye stimulated in the posterior → anterior (P → A) direction, slow phase eye velocity (SPEV) increased by 3.5-5°/s. When the rabbit was roll-tilted 30° onto the side of the eye stimulated in the A → P direction, SPEV decreased to ~2.5°/s. We also tested the effect of roll-tilt after prolonged optokinetic stimulation had induced a negative optokinetic afternystagmus (OKAN II). In this condition, the SPEV occurred in the dark, "open loop." Modulation of SPEV of OKAN II depended on the direction of the nystagmus and was consistent with that observed during "closed loop" HOKS. Dynamic roll-tilt influenced SPEV evoked by HOKS in a similar way. The amplitude and the phase of SPEV depended on the frequency of vestibular oscillation and on HOKS velocity. We conclude that the change in the linear acceleration of the gravity vector with respect to the head during roll-tilt modulates the gain of SPEV depending on its direction. This modulation improves gaze stability at different image retinal slip velocities caused by head roll-tilt during centric or eccentric head movement. PMID:21735244

  1. Resonance in a head massager

    NASA Astrophysics Data System (ADS)

    Ribeiro, Jair Lúcio Prados

    2015-04-01

    Mechanical structures such as pendula, bridges, or buildings always exhibit one (or more) natural oscillation frequency.1 If that structure is subjected to oscillatory forces of this same frequency, resonance occurs, with consequent increase of the structure oscillation amplitude. There is no shortage of simple experiments for demonstrating resonance in high school classes using a variety of materials, such as saw blades,2 guitars,3 pendulums,4 wine glasses,5 bottles,6 Ping-Pong balls,7 and pearl strings.8 We present here an experimental demonstration using only an inexpensive head (or scalp) massager, which can be purchased for less than a dollar.

  2. Reactor Pressure Vessel Head Packaging & Disposal

    SciTech Connect

    Wheeler, D. M.; Posivak, E.; Freitag, A.; Geddes, B.

    2003-02-26

    Reactor Pressure Vessel (RPV) Head replacements have come to the forefront due to erosion/corrosion and wastage problems resulting from the susceptibility of the RPV Head alloy steel material to water/boric acid corrosion from reactor coolant leakage through the various RPV Head penetrations. A case in point is the recent Davis-Besse RPV Head project, where detailed inspections in early 2002 revealed significant wastage of head material adjacent to one of the Control Rod Drive Mechanism (CRDM) nozzles. In lieu of making ASME weld repairs to the damaged head, Davis-Besse made the decision to replace the RPV Head. The decision was made on the basis that the required weld repair would be too extensive and almost impractical. This paper presents the packaging, transport, and disposal considerations for the damaged Davis-Besse RPV Head. It addresses the requirements necessary to meet Davis Besse needs, as well as the regulatory criteria, for shipping and burial of the head. It focuses on the radiological characterization, shipping/disposal package design, site preparation and packaging, and the transportation and emergency response plans that were developed for the Davis-Besse RPV Head project.

  3. Head movement during walking in the cat.

    PubMed

    Zubair, Humza N; Beloozerova, Irina N; Sun, Hai; Marlinski, Vladimir

    2016-09-22

    Knowledge of how the head moves during locomotion is essential for understanding how locomotion is controlled by sensory systems of the head. We have analyzed head movements of the cat walking along a straight flat pathway in the darkness and light. We found that cats' head left-right translations, and roll and yaw rotations oscillated once per stride, while fore-aft and vertical translations, and pitch rotations oscillated twice. The head reached its highest vertical positions during second half of each forelimb swing, following maxima of the shoulder/trunk by 20-90°. Nose-up rotation followed head upward translation by another 40-90° delay. The peak-to-peak amplitude of vertical translation was ∼1.5cm and amplitude of pitch rotation was ∼3°. Amplitudes of lateral translation and roll rotation were ∼1cm and 1.5-3°, respectively. Overall, cats' heads were neutral in roll and 10-30° nose-down, maintaining horizontal semicircular canals and utriculi within 10° of the earth horizontal. The head longitudinal velocity was 0.5-1m/s, maximal upward and downward linear velocities were ∼0.05 and ∼0.1m/s, respectively, and maximal lateral velocity was ∼0.05m/s. Maximal velocities of head pitch rotation were 20-50°/s. During walking in light, cats stood 0.3-0.5cm taller and held their head 0.5-2cm higher than in darkness. Forward acceleration was 25-100% higher and peak-to-peak amplitude of head pitch oscillations was ∼20°/s larger. We concluded that, during walking, the head of the cat is held actively. Reflexes appear to play only a partial role in determining head movement, and vision might further diminish their role. PMID:27339731

  4. Heading in football. Part 1: Development of biomechanical methods to investigate head response

    PubMed Central

    Shewchenko, N; Withnall, C; Keown, M; Gittens, R; Dvorak, J

    2005-01-01

    Objectives: There has been growing controversy regarding long term effects of repeated low severity head impacts such as when heading a football. However, there are few scientific data substantiating these concerns in terms of the biomechanical head response to impact. The present study aimed to develop a research methodology to investigate the biomechanical response of human subjects during intentional heading and identify strategies for reducing head impact severity. Methods: A controlled laboratory study was carried out with seven active football players, aged 20–23 and of average stature and weight. The subjects were fitted with photographic targets for kinematic analysis and instrumented to measure head linear/angular accelerations and neck muscle activity. Balls were delivered at two speeds (6 m/s and 8 m/s) as the subjects executed several specific forward heading manoeuvres in the standing position. Heading speeds up to 11 m/s were seen when the head closing speed was considered. One subject demonstrating averaged flexion–extension muscle activity phased with head acceleration data and upper torso kinematics was used to validate a biofidelic 50th percentile human model with a detailed head and neck. The model was exercised under ball incoming speeds of 6–7 m/s with parameter variations including torso/head alignment, neck muscle tensing, and follow through. The model output was subsequently compared with additional laboratory tests with football players (n = 3). Additional heading scenarios were investigated including follow through, non-active ball impact, and non-contact events. Subject and model head responses were evaluated with peak linear and rotational accelerations and maximum incremental head impact power. Results: Modelling of neck muscle tensing predicted lower head accelerations and higher neck loads whereas volunteer head acceleration reductions were not consistent. Modelling of head–torso alignment predicted a modest reduction in

  5. Anatomy of the infant head

    SciTech Connect

    Bosma, J.F.

    1986-01-01

    This text is mainly an atlas of illustration representing the dissection of the head and upper neck of the infant. It was prepared by the author over a 20-year period. The commentary compares the anatomy of the near-term infant with that of a younger fetus, child, and adult. As the author indicates, the dearth of anatomic information about postnatal anatomic changes represents a considerable handicap to those imaging infants. In part 1 of the book, anatomy is related to physiologic performance involving the pharynx, larynx, and mouth. Sequential topics involve the regional anatomy of the head (excluding the brain), the skeleton of the cranium, the nose, orbit, mouth, larynx, pharynx, and ear. To facilitate use of this text as a reference, the illustrations and text on individual organs are considered separately (i.e., the nose, the orbit, the eye, the mouth, the larynx, the pharynx, and the ear). Each part concerned with a separate organ includes materials from the regional illustrations contained in part 2 and from the skeleton, which is treated in part 3. Also included in a summary of the embryologic and fetal development of the organ.

  6. A Pre-Hispanic Head

    PubMed Central

    Bianucci, Raffaella; Jeziorska, Maria; Lallo, Rudy; Mattutino, Grazia; Massimelli, Massimo; Phillips, Genevieve; Appenzeller, Otto

    2008-01-01

    This report on a male head revealed biologic rhythms, as gleaned from hydrogen isotope ratios in hair, consistent with a South-American origin and Atomic Mass Spectrometry radiocarbon dating (AMS) compatible with the last pre-Hispanic period (1418–1491 AD, 95.4% probability). Biopsies showed exceptionally well-preserved tissues. The hair contained high levels of toxic elements (lead, arsenic and mercury) incompatible with life. There was no evidence for lead deposition in bone consistent with post-mortem accumulation of this toxic element in the hair. We propose that the high content of metals in hair was the result of metabolic activity of bacteria leading to metal complexation in extra cellular polymeric substances (EPS). This is a recognized protective mechanism for bacteria that thrive in toxic environments. This mechanism may account for the tissues preservation and gives a hint at soil composition where the head was presumably buried. Our results have implications for forensic toxicology which has, hitherto, relied on hair analyses as one means to reconstruct pre-mortem metabolism and for detecting toxic elements accumulated during life. Our finding also has implications for other archaeological specimens where similar circumstances may distort the results of toxicological studies. PMID:18446229

  7. Clinical Trials in Head Injury

    PubMed Central

    NARAYAN, RAJ K.; MICHEL, MARY ELLEN; Ansell, Beth; Baethmann, Alex; Biegon, Anat; Bracken, Michael B.; Bullock, M. Ross; Choi, Sung C.; Clifton, Guy L.; Contant, Charles F.; Coplin, William M.; Dietrich, W. Dalton; Ghajar, Jamshid; Grady, Sean M.; Grossman, Robert G.; Hall, Edward D.; Heetderks, William; Hovda, David A.; Jallo, Jack; Katz, Russell L.; Knoller, Nachshon; Kochanek, Patrick M.; Maas, Andrew I.; Majde, Jeannine; Marion, Donald W.; Marmarou, Anthony; Marshall, Lawrence F.; McIntosh, Tracy K.; Miller, Emmy; Mohberg, Noel; Muizelaar, J. Paul; Pitts, Lawrence H.; Quinn, Peter; Riesenfeld, Gad; Robertson, Claudia S.; Strauss, Kenneth I.; Teasdale, Graham; Temkin, Nancy; Tuma, Ronald; Wade, Charles; Walker, Michael D.; Weinrich, Michael; Whyte, John; Wilberger, Jack; Young, A. Byron; Yurkewicz, Lorraine

    2006-01-01

    Traumatic brain injury (TBI) remains a major public health problem globally. In the United States the incidence of closed head injuries admitted to hospitals is conservatively estimated to be 200 per 100,000 population, and the incidence of penetrating head injury is estimated to be 12 per 100,000, the highest of any developed country in the world. This yields an approximate number of 500,000 new cases each year, a sizeable proportion of which demonstrate signficant long-term disabilities. Unfortunately, there is a paucity of proven therapies for this disease. For a variety of reasons, clinical trials for this condition have been difficult to design and perform. Despite promising pre-clinical data, most of the trials that have been performed in recent years have failed to demonstrate any significant improvement in outcomes. The reasons for these failures have not always been apparent and any insights gained were not always shared. It was therefore feared that we were running the risk of repeating our mistakes. Recognizing the importance of TBI, the National Institute of Neurological Disorders and Stroke (NINDS) sponsored a workshop that brought together experts from clinical, research, and pharmaceutical backgrounds. This workshop proved to be very informative and yielded many insights into previous and future TBI trials. This paper is an attempt to summarize the key points made at the workshop. It is hoped that these lessons will enhance the planning and design of future efforts in this important field of research. PMID:12042091

  8. Head and neck position sense.

    PubMed

    Armstrong, Bridget; McNair, Peter; Taylor, Denise

    2008-01-01

    Traumatic minor cervical strains are common place in high-impact sports (e.g. tackling) and premature degenerative changes have been documented in sports people exposed to recurrent impact trauma (e.g. scrummaging in rugby) or repetitive forces (e.g. Formula 1 racing drivers, jockeys). While proprioceptive exercises have been an integral part of rehabilitation of injuries in the lower limb, they have not featured as prominently in the treatment of cervical injuries. However, head and neck position sense (HNPS) testing and re-training may have relevance in the management of minor sports-related neck injuries, and play a role in reducing the incidence of ongoing pain and problems with function. For efficacious programmes to be developed and tested, fundamental principles associated with proprioception in the cervical spine should be considered. Hence, this article highlights the importance of anatomical structures in the cervical spine responsible for position sense, and how their interaction with the CNS affects our ability to plan and execute effective purposeful movements. This article includes a review of studies examining position sense in subjects with and without pathology and describes the effects of rehabilitation programmes that have sought to improve position sense. In respect to the receptors providing proprioceptive information for the CNS, the high densities and complex arrays of spindles found in cervical muscles suggest that these receptors play a key role. There is some evidence suggesting that ensemble encoding of discharge patterns from muscle spindles is relayed to the CNS and that a pattern recognition system is used to establish joint position and movement. Sensory information from neck proprioceptive receptors is processed in tandem with information from the vestibular system. There are extensive anatomical connections between neck proprioceptive inputs and vestibular inputs. If positional information from the vestibular system is inaccurate or

  9. Modeling heading in adult soccer players.

    PubMed

    Ponce, Ernesto; Ponce, Daniel; Andresen, Max

    2014-01-01

    Heading soccer balls can generate mild brain injuries and in the long run can lead to difficulty in solving problems, memory deficits, and language difficulties. Researchers evaluated the effects on the head for both correct and incorrect heading techniques. They based the head's geometry on medical images. They determined the injury's magnitude by comparing the neurological tissue's resistance with predictions of the generated stresses. The evaluation examined fast playing conditions in adult soccer, taking into account the ball's speed and the type of impact. Mathematical simulations using the finite element method indicated that correctly heading balls arriving at moderate speed presents a low risk of brain injury. However, damage can happen around the third cervical vertebra. These results coincide with medical studies. Incorrect heading greatly increases the brain injury risk and can alter the parietal area. PMID:25248195

  10. Fusobacterial head and neck infections in children.

    PubMed

    Brook, Itzhak

    2015-07-01

    Fusobacterium species are increasingly recognized as a cause of head and neck infections in children. These infections include acute and chronic otitis, sinusitis, mastoiditis, and tonsillitis; peritonsillar and retropharyngeal abscesses; Lemierre syndrome; post-anginal cervical lymphadenitis; and periodontitis. They can also be involved in brain abscess and bacteremia associated with head and neck infections. This review describes the clinical spectrum of head and neck fusobacterial infection in children and their management. PMID:25980688

  11. Paragangliomas of the Head and Neck.

    PubMed

    Woolen, Sean; Gemmete, Joseph J

    2016-05-01

    Paragangliomas of the head and neck are rare vascular skull-base tumors derived from the paraganglionic system with an estimated incidence of 1:30,000 accounting for 3% of all paragangliomas. The most common paraganglioma locations of the head and neck in descending order are the carotid body, jugular, tympanic, and vagal paragangliomas. This article discusses the clinical characterics, normal anatamy, imaging findings and protocols, pathology, staging, and differential diagnosis for paragangliomas of the head and neck. PMID:27154608

  12. Head-Mounted and Head-Up Display Glossary

    NASA Technical Reports Server (NTRS)

    Newman, Richard L.; Allen, J. Edwin W. (Technical Monitor)

    1997-01-01

    One of the problems in head-up and helmet-mounted display (HMD) literature has been a lack of standardization of words and abbreviations. Several different words have been used for the same concept; for example, flight path angle, flight path marker, velocity vector, and total velocity vector all refer to the same thing. In other cases, the same term has been used with two different meanings, such as binocular field-of-view which means the field-of-view visible to both left and right eyes according to some or the field-of-view visible to either the left or right eye or both according to others. Many of the terms used in HMD studies have not been well-defined. We need to have a common language to ensure that system descriptions are communicated. As an example, the term 'stabilized' has been widely used with two meanings. 'Roll-stabilized' has been used to mean a symbol which rotates to indicate the roll or bank of the aircraft. 'World-stabilized' and 'head-stabilized' have both been used to indicate symbols which move to remain fixed with respect to external objects. HMDs present unique symbology problems not found in HUDs. Foremost among these is the issue of maintaining spatial orientation of the symbols. All previous flight displays, round dial instruments, HDDs, and HUDs have been fixed in the cockpit. With the HMD, the flight display can move through a large angle. The coordinates use in transforming from the real-world to the aircraft to the HMD have not been consistently defined. This glossary contains terms relating to optics and vision, displays, and flight information, weapons and aircraft systems. Some definitions, such as Navigation Display, have been added to clarify the definitions for Primary Flight Display and Primary Flight Reference. A list of HUD/HMD related abbreviations is also included.

  13. Bilateral internuclear ophthalmoplegia following mild head injury.

    PubMed

    Muthukumar, N; Veerarajkumar, N; Madeswaran, K

    2001-05-01

    A 7-year-old child presented with bilateral internuclear ophthalmoplegia (INO) following a trivial head injury. CT was normal. MRI revealed a pontine lesion. Two months after the injury the patient was neurologically normal. INO following head injury is rare. Rarer still is INO following mild head injury. To date, only four cases of INO had been reported following mild head injury; the present case is the fifth and the first in which the lesion was documented using MRI. The relevant literature is reviewed. PMID:11417420

  14. Trial of Postoperative Radiation, Cisplatin, and Panitumumab in Locally Advanced Head and Neck Cancer

    ClinicalTrials.gov

    2016-06-28

    Cancer of Head; Cancer of Head and Neck; Cancer of Neck; Cancer of the Head; Cancer of the Head and Neck; Cancer of the Neck; Head and Neck Cancer; Head Cancer; Head Neoplasms; Head, Neck Neoplasms; Neck Cancer; Neck Neoplasms; Neoplasms, Head; Neoplasms, Head and Neck; Neoplasms, Neck; Neoplasms, Upper Aerodigestive Tract; UADT Neoplasms; Upper Aerodigestive Tract Neoplasms

  15. Image data rate converter having a drum with a fixed head and a rotatable head

    NASA Technical Reports Server (NTRS)

    Billingsley, F. C. (Inventor)

    1973-01-01

    A data-rate converter is disclosed comprising a rotatable data-storing drum with at least one fixed read/record head and a rotatable read/record head. The latter is rotatable in a circular path about the drum axis of rotation. The drum is positionable in any one of a plurality of axial positions with respect to the heads, so that at least one drum track is aligned with the fixed head in one drum position and with the rotatable head in another drum position. When a track is aligned with the fixed head, data may be recorded therin or read out therefrom at a rate which is a function of drum rotation, while when aligned with the rotatable head, data may be recorded or read out at a rate which is a function of the rates and directions of rotation of both the drum and the head.

  16. Radial head button holing: a cause of irreducible anterior radial head dislocation.

    PubMed

    Shin, Su-Mi; Chai, Jee Won; You, Ja Yeon; Park, Jina; Bae, Kee Jeong

    2016-10-01

    "Buttonholing" of the radial head through the anterior joint capsule is a known cause of irreducible anterior radial head dislocation associated with Monteggia injuries in pediatric patients. To the best of our knowledge, no report has described an injury consisting of buttonholing of the radial head through the annular ligament and a simultaneous radial head fracture in an adolescent. In the present case, the radiographic findings were a radial head fracture with anterior dislocation and lack of the anterior fat pad sign. Magnetic resonance imaging (MRI) clearly demonstrated anterior dislocation of the fractured radial head through the torn annular ligament. The anterior joint capsule and proximal portion of the annular ligament were interposed between the radial head and capitellum, preventing closed reduction of the radial head. Familiarity with this condition and imaging findings will aid clinicians to make a proper diagnosis and fast decision to perform an open reduction. PMID:27502623

  17. An evaluation of flight path formats head-up and head-down

    NASA Technical Reports Server (NTRS)

    Sexton, George A.; Moody, Laura E.; Evans, Joanne; Williams, Kenneth E.

    1988-01-01

    Flight path primary flight display formats were incorporated on head-up and head-down electronic displays and integrated into an Advanced Concepts Flight Simulator. Objective and subjective data were collected while ten airline pilots evaluated the formats by flying an approach and landing task under various ceiling, visibility and wind conditions. Deviations from referenced/commanded airspeed, horizontal track, vertical track and touchdown point were smaller using the head-up display (HUD) format than the head-down display (HDD) format, but not significantly smaller. Subjectively, the pilots overwhelmingly preferred (1) flight path formats over attitude formats used in current aircraft, and (2) the head-up presentation over the head-down, primarily because it eliminated the head-down to head-up transition during low visibility landing approaches. This report describes the simulator, the flight displays, the format evaluation, and the results of the objective and subjective data.

  18. When climate twitches, evolution takes great leaps

    SciTech Connect

    Kerr, R.A.

    1992-09-18

    Earth's climate system has ridden a slow roller coaster for the past 60 million years. It warmed gradually until about 53 million years ago, reaching a peak that brought crocodiles to northern Canada; then it entered a long, undulating downgrade toward the ice-age world of the past few million years. Because the same span of time brought major evolutionary changes, including the rise of modern mammals, paleontologists have long assumed that these slow temperature changes helped spur the processes of evolution. But recent findings have suggested that another, more potent mechanisms was also at work: Abrupt climate excursions, superimposed on these long-term trends, have now been linked to rapid periods of mammal evolution. The evidence for short, sharp evolutionary shocks comes from studies of a pair of mirror-image climate shifts at opposite ends of the Eocene epoch, 55 million and 33.5 million years ago. In both cases, researchers studying the record of climate preserved in sea-floor sediments have found that a gradual climate change-warming in the first case, cooling in the second - suddenly steepened into a short-lived pulse of extreme warming or cooling. The short time scale of these events and their clear coincidence with turning points in the evolution of mammals are providing the tightest links yet between global climate change and evolution on land.

  19. Where Is Health Care Headed?

    PubMed

    Bland, Jeffrey

    2016-06-01

    Looking at the trends, developments, and discoveries points us toward the future, but it is only when we consider these in the context of our understanding about the origins of disease that we can truly gain a clearer view of where health care is headed. This is the view that moves us from a focus on the diagnosis and treatment of a disease to an understanding of the origin of the alteration in function in the individual. This change in both perspective and understanding of the origin of disease is what will lead us to a systems approach to health care that delivers personalized and precision care that is based on the inherent rehabilitative power that resides within the genome. PMID:27547161

  20. Natural head position: An overview

    PubMed Central

    Meiyappan, N.; Tamizharasi, S.; Senthilkumar, K. P.; Janardhanan, K.

    2015-01-01

    Cephalometrics has given us a different perspective of interpreting various skeletal problems in the dentofacial complex. Natural head position (NHP) is a reproducible, physiologically determined aspect of function. To determine NHP, a horizontal or vertical reference line outside the crania was used, but preference was given generally to the horizontal. Various intra and extracranial cephalometric horizontal reference planes have been used to formulate diagnosis and plan individualized treatment for an integrated correction of the malocclusion cephalometrics is constantly undergoing refinements in its techniques and analyses to improve the clinical applications. Even though various methods for establishing NHP have been proposed, still it remains a challenge to the clinicians to implement the concept of NHP thoroughly in all the stages of treatment because of practical difficulties in the clinical scenario. PMID:26538891

  1. Reactor vessel lower head integrity

    SciTech Connect

    Rubin, A.M.

    1997-02-01

    On March 28, 1979, the Three Mile Island Unit 2 (TMI-2) nuclear power plant underwent a prolonged small break loss-of-coolant accident that resulted in severe damage to the reactor core. Post-accident examinations of the TMI-2 reactor core and lower plenum found that approximately 19,000 kg (19 metric tons) of molten material had relocated onto the lower head of the reactor vessel. Results of the OECD TMI-2 Vessel Investigation Project concluded that a localized hot spot of approximately 1 meter diameter had existed on the lower head. The maximum temperature on the inner surface of the reactor pressure vessel (RPV) in this region reached 1100{degrees}C and remained at that temperature for approximately 30 minutes before cooling occurred. Even under the combined loads of high temperature and high primary system pressure, the TMI-2 RPV did not fail. (i.e. The pressure varied from about 8.5 to 15 MPa during the four-hour period following the relocation of melt to the lower plenum.) Analyses of RPV failure under these conditions, using state-of-the-art computer codes, predicted that the RPV should have failed via local or global creep rupture. However, the vessel did not fail; and it has been hypothesized that rapid cooling of the debris and the vessel wall by water that was present in the lower plenum played an important role in maintaining RPV integrity during the accident. Although the exact mechanism(s) of how such cooling occurs is not known, it has been speculated that cooling in a small gap between the RPV wall and the crust, and/or in cracks within the debris itself, could result in sufficient cooling to maintain RPV integrity. Experimental data are needed to provide the basis to better understand these phenomena and improve models of RPV failure in severe accident codes.

  2. Radiation therapy for head and neck neoplasms

    SciTech Connect

    Wang, C.C.

    1990-01-01

    This book presents the clinical manifestations of disease, applied anatomy pertaining to the management of head and neck tumors, and results of conventional radiation therapy for uncommon tumors have been explored. It also contains an additional chapter on altered fractionation radiation therapy pertaining to irradiation of major head and neck tumors.

  3. Head Start Impact Study. Final Report

    ERIC Educational Resources Information Center

    Puma, Michael; Bell, Stephen; Cook, Ronna; Heid, Camilla; Shapiro, Gary; Broene, Pam; Jenkins, Frank; Fletcher, Philip; Quinn, Liz; Friedman, Janet; Ciarico, Janet; Rohacek, Monica; Adams, Gina; Spier, Elizabeth

    2010-01-01

    This report addresses the following four questions by reporting on the impacts of Head Start on children and families during the children's preschool, kindergarten, and 1st grade years: (1) What difference does Head Start make to key outcomes of development and learning (and in particular, the multiple domains of school readiness) for low-income…

  4. Head Start Impact Study. Technical Report

    ERIC Educational Resources Information Center

    Puma, Michael; Bell, Stephen; Cook, Ronna; Heid, Camilla; Shapiro, Gary; Broene, Pam; Jenkins, Frank; Fletcher, Philip; Quinn, Liz; Friedman, Janet; Ciarico, Janet; Rohacek, Monica; Adams, Gina; Spier, Elizabeth

    2010-01-01

    This Technical Report is designed to provide technical detail to support the analysis and findings presented in the "Head Start Impact Study Final Report" (U.S. Department of Health and Human Services, January 2010). Chapter 1 provides an overview of the Head Start Impact Study and its findings. Chapter 2 provides technical information on the…

  5. The Texas Head Start Metro Models.

    ERIC Educational Resources Information Center

    Riley, Mary Tom, Ed.; Flores, Alfredo R., Ed.

    The Texas Metro Network (TMN) is an informal group of Head Start Directors and Executive Directors organized for the purposes of improving the delivery of training and technical assistance and for assisting communication between large scale Head Start programs in the metropolitan areas of Texas. In pursuit of these aims, each member unit of the…

  6. The Role of the Primary School Head.

    ERIC Educational Resources Information Center

    Davies, Lester

    1987-01-01

    This study uses Henry Mintzberg's structural observation method to examine British primary school head teachers' work patterns and determine the nature of their role. Head teachers' days were characterized by brevity, variety, and fragmentation similar to those discussed in findings of other empirical managerial studies. Leadership roles stressed…

  7. Using Music with Head Start Children.

    ERIC Educational Resources Information Center

    Griffin, Louise

    This pamphlet describes the function of music in Head Start programs. Suggestions are made to help children sense motion and develop their self-concepts and motor coordination skills through rhythmic songs and activities. The construction and use of rhythm instruments are suggested as a means of involving mothers in Head Start programs. Certain…

  8. High density tape/head interface study

    NASA Technical Reports Server (NTRS)

    Csengery, L. C.

    1983-01-01

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

  9. 21 CFR 868.1930 - Stethoscope head.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Stethoscope head. 868.1930 Section 868.1930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1930 Stethoscope head. (a) Identification....

  10. 21 CFR 868.1930 - Stethoscope head.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stethoscope head. 868.1930 Section 868.1930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1930 Stethoscope head. (a) Identification....

  11. 21 CFR 868.1930 - Stethoscope head.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Stethoscope head. 868.1930 Section 868.1930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1930 Stethoscope head. (a) Identification....

  12. 21 CFR 868.1930 - Stethoscope head.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Stethoscope head. 868.1930 Section 868.1930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1930 Stethoscope head. (a) Identification....

  13. 21 CFR 868.1930 - Stethoscope head.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Stethoscope head. 868.1930 Section 868.1930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1930 Stethoscope head. (a) Identification....

  14. 49 CFR 572.32 - Head.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Head. 572.32 Section 572.32 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES Hybrid III Test Dummy § 572.32 Head....

  15. "Starfish" Heater Head For Stirling Engine

    NASA Technical Reports Server (NTRS)

    Vitale, N.

    1993-01-01

    Proposed "starfish" heater head for Stirling engine enables safe use of liquid sodium as heat-transfer fluid. Sodium makes direct contact with heater head but does not come in contact with any structural welds. Design concept minimizes number of, and simplifies nonstructural thermal welds and facilitates inspection of such welds.

  16. 49 CFR 572.82 - Head.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Head. 572.82 Section 572.82 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.82 Head. The...

  17. 49 CFR 572.82 - Head.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Head. 572.82 Section 572.82 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.82 Head. The...

  18. 49 CFR 572.82 - Head.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Head. 572.82 Section 572.82 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.82 Head. The...

  19. 49 CFR 572.82 - Head.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Head. 572.82 Section 572.82 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.82 Head. The...

  20. 49 CFR 572.82 - Head.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Head. 572.82 Section 572.82 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.82 Head. The...

  1. 49 CFR 572.112 - Head assembly.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... to its application in a test. (2) Clean the impact surface of the head skin and impact plate surface... degrees with the impact surface and its anterior-posterior axis is horizontal ±1 degree. (4) Drop the head... means that ensures a smooth, clean release into a rigidly supported flat horizontal steel plate,...

  2. 49 CFR 572.112 - Head assembly.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... to its application in a test. (2) Clean the impact surface of the head skin and impact plate surface... degrees with the impact surface and its anterior-posterior axis is horizontal ±1 degree. (4) Drop the head... means that ensures a smooth, clean release into a rigidly supported flat horizontal steel plate,...

  3. Marshall Space Flight Center head development program

    NASA Technical Reports Server (NTRS)

    Harrer, Jim

    1994-01-01

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

  4. University Department Heads: Agents of Changes.

    ERIC Educational Resources Information Center

    Reyna, Sheila Sullivan

    A theoretical framework for the process of faculty renewal in the 1980s was proposed, based on examination of the role of department heads as in-house agents of change for staff development. Support for the theory was sought using three empirical statements to test the relationship of department heads' manipulative orientation and social insight…

  5. Borrelia recurrentis in Head Lice, Ethiopia

    PubMed Central

    Boutellis, Amina; Mediannikov, Oleg; Bilcha, Kassahun Desalegn; Ali, Jemal; Campelo, Dayana; Barker, Stephen C.

    2013-01-01

    Since the 1800s, the only known vector of Borrelia recurrentis has been the body louse. In 2011, we found B. recurrentis DNA in 23% of head lice from patients with louse-borne relapsing fever in Ethiopia. Whether head lice can transmit these bacteria from one person to another remains to be determined. PMID:23648147

  6. Administration for Children and Families: Head Start

    ERIC Educational Resources Information Center

    US Department of Health and Human Services, 2010

    2010-01-01

    This paper presents an overview of the Head Start program. Under the American Recovery and Reinvestment Act (Recovery Act), $1 billion will be provided to the Office of Head Start to promote the school readiness of low-income children, including children on federally-recognized reservations and children of migratory farm workers, by enhancing…

  7. Head Injury in Partner-Abusive Men.

    ERIC Educational Resources Information Center

    Rosenbaum, Alan; And Others

    1994-01-01

    Fifty-three partner-abusive men, 45 maritally satisfied, and 32 maritally discordant, nonviolent men were evaluated for past history of head injury. Logistic regressions confirmed head injury was significant predictor of being a batterer. Implications of findings for both marital aggression and posthead injury rehabilitation are discussed. (Author)

  8. Abusive head trauma: past, present, and future.

    PubMed

    Narang, Sandeep; Clarke, Jennifer

    2014-12-01

    Abusive head trauma has a robust and interesting scientific history. Recently, the American Academy of Pediatrics has endorsed a change in terminology to a term that is more general in describing the vast array of abusive mechanisms that can result in pediatric head injury. Simply defined, abusive head trauma is "child physical abuse that results in injury to the head or brain." Abusive head trauma is a relatively common cause of childhood neurotrauma, with an estimated incidence of 16 to 33 cases per 100,000 children per year in the first 2 years of life. Clinical findings are variable; AHT should be considered in all children with neurologic signs and symptoms, especially if no or only mild trauma is described. Subdural and retinal hemorrhages are the most common findings. The current best evidence-based literature has identified some features--apnea and severe retinal hemorrhages--that reliably discriminate abusive from accidental injury. Longitudinal studies of outcomes in abusive head trauma patients demonstrate that approximately one-third of the children are severely disabled, one third of them are moderately disabled, and one third have no or only mild symptoms. Abusive head trauma cases are complex cases that require a rigorous, multidisciplinary team approach. The clinician can establish this diagnosis with confidence if he/she maintains a high index of suspicion for the diagnosis, has knowledge of the signs, symptoms, and risk factors of abusive head trauma, and reasonably excludes other etiologies on the differential diagnosis. PMID:25316728

  9. Head Start. What Works Clearinghouse Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2015

    2015-01-01

    "Head Start" is a national, federally funded program that provides services to promote school readiness for children from birth to age 5 from predominantly low-income families. Based on a review of the research, the WWC found "Head Start" to have potentially positive effects on general reading achievement and no discernible…

  10. Newborns' Head Orientation toward Sounds Within Hemifields.

    ERIC Educational Resources Information Center

    Fenwick, Kimberley; And Others

    This experiment examined the accuracy with which newborn infants orient their heads toward a sound positioned off midline within hemifields. The study also evaluated newborns' ability to update the angle of their head turn to match a change in localization of an ongoing sound. Alert newborns were held in a supine position and presented a sound at…

  11. Systematic Biases in Human Heading Estimation

    PubMed Central

    Cuturi, Luigi F.; MacNeilage, Paul R.

    2013-01-01

    Heading estimation is vital to everyday navigation and locomotion. Despite extensive behavioral and physiological research on both visual and vestibular heading estimation over more than two decades, the accuracy of heading estimation has not yet been systematically evaluated. Therefore human visual and vestibular heading estimation was assessed in the horizontal plane using a motion platform and stereo visual display. Heading angle was overestimated during forward movements and underestimated during backward movements in response to both visual and vestibular stimuli, indicating an overall multimodal bias toward lateral directions. Lateral biases are consistent with the overrepresentation of lateral preferred directions observed in neural populations that carry visual and vestibular heading information, including MSTd and otolith afferent populations. Due to this overrepresentation, population vector decoding yields patterns of bias remarkably similar to those observed behaviorally. Lateral biases are inconsistent with standard Bayesian accounts which predict that estimates should be biased toward the most common straight forward heading direction. Nevertheless, lateral biases may be functionally relevant. They effectively constitute a perceptual scale expansion around straight ahead which could allow for more precise estimation and provide a high gain feedback signal to facilitate maintenance of straight-forward heading during everyday navigation and locomotion. PMID:23457631

  12. Historical Perspectives on Project Head Start.

    ERIC Educational Resources Information Center

    Slaughter, Diana T.

    Historical changes in the emphasis and focus of Project Head Start from 1965 to the present are briefly reviewed in this paper. Head Start was conceived of as primary prevention designed to enable children from lower income families to obtain educational prerequisites to formal schooling. The early years of the project were also characterized by…

  13. Heading Tuning in Macaque Area V6

    PubMed Central

    Fan, Reuben H.; Liu, Sheng; DeAngelis, Gregory C.

    2015-01-01

    Cortical areas, such as the dorsal subdivision of the medial superior temporal area (MSTd) and the ventral intraparietal area (VIP), have been shown to integrate visual and vestibular self-motion signals. Area V6 is interconnected with areas MSTd and VIP, allowing for the possibility that V6 also integrates visual and vestibular self-motion cues. An alternative hypothesis in the literature is that V6 does not use these sensory signals to compute heading but instead discounts self-motion signals to represent object motion. However, the responses of V6 neurons to visual and vestibular self-motion cues have never been studied, thus leaving the functional roles of V6 unclear. We used a virtual reality system to examine the 3D heading tuning of macaque V6 neurons in response to optic flow and inertial motion stimuli. We found that the majority of V6 neurons are selective for heading defined by optic flow. However, unlike areas MSTd and VIP, V6 neurons are almost universally unresponsive to inertial motion in the absence of optic flow. We also explored the spatial reference frames of heading signals in V6 by measuring heading tuning for different eye positions, and we found that the visual heading tuning of most V6 cells was eye-centered. Similar to areas MSTd and VIP, the population of V6 neurons was best able to discriminate small variations in heading around forward and backward headings. Our findings support the idea that V6 is involved primarily in processing visual motion signals and does not appear to play a role in visual–vestibular integration for self-motion perception. SIGNIFICANCE STATEMENT To understand how we successfully navigate our world, it is important to understand which parts of the brain process cues used to perceive our direction of self-motion (i.e., heading). Cortical area V6 has been implicated in heading computations based on human neuroimaging data, but direct measurements of heading selectivity in individual V6 neurons have been lacking. We

  14. Head Start Impact Study: First Year Findings. Executive Summary

    ERIC Educational Resources Information Center

    Puma, Michael; Bell, Stephen; Cook, Ronna; Heid, Camilla; Lopez, Michael

    2005-01-01

    The Congressionally-mandated Head Start Impact Study is being conducted across 84 nationally representative grantee/delegate agencies. Approximately 5,000 newly entering 3- and 4-year-old children applying for Head Start were randomly assigned to either a Head Start group that had access to Head Start program services or to a non-Head Start group…

  15. A Guide for Providing Social Services in Head Start.

    ERIC Educational Resources Information Center

    Administration for Children, Youth, and Families (DHHS), Washington, DC. Head Start Bureau.

    The social services component of Head Start links family, Head Start, and the community. This document addresses components of Head Start, providing Head Start staff who have social services responsibility with a guide to the provision of services to families. The chapters in the guide are: (1) "Overview of Head Start," including its origins,…

  16. Bobbling head in a young subject

    PubMed Central

    Bhattacharyya, Kalyan B.; Deb, Sumit; Ghosh, S. N.; Mondal, S.

    2014-01-01

    Bobble-head Doll Syndrome is a rare and unique movement disorder found in children. Clinically, it is characterized by a to and fro or side to side movement of the head at the frequency of 2 to 3 Hz. It is mostly associated with cystic lesions around the third ventricle, choroid plexus papilloma, aqueductal stenosis and other rare disorders. An eleven year old child presented in the outpatient department with continuous to and fro movement of the head and declining vision for the last one month. MRI Scan showed a large contrast-enhanced lesion in the region of the third ventricle along with gross hydrocephalus. Ventriculo-peritoneal shunt was inserted and the movements of the head disappeared completely. Bobble-head doll syndrome is a rare condition and therefore this case is presented and the literature reviewed. PMID:25506155

  17. Bobbling head in a young subject.

    PubMed

    Bhattacharyya, Kalyan B; Deb, Sumit; Ghosh, S N; Mondal, S

    2014-10-01

    Bobble-head Doll Syndrome is a rare and unique movement disorder found in children. Clinically, it is characterized by a to and fro or side to side movement of the head at the frequency of 2 to 3 Hz. It is mostly associated with cystic lesions around the third ventricle, choroid plexus papilloma, aqueductal stenosis and other rare disorders. An eleven year old child presented in the outpatient department with continuous to and fro movement of the head and declining vision for the last one month. MRI Scan showed a large contrast-enhanced lesion in the region of the third ventricle along with gross hydrocephalus. Ventriculo-peritoneal shunt was inserted and the movements of the head disappeared completely. Bobble-head doll syndrome is a rare condition and therefore this case is presented and the literature reviewed. PMID:25506155

  18. Intrapartum sonographic imaging of fetal head asynclitism.

    PubMed

    Ghi, T; Youssef, A; Pilu, G; Malvasi, A; Ragusa, A

    2012-02-01

    Anterior asynclitism was suspected on digital examination of a laboring woman with late arrest of dilatation and no evidence of fetal head progression. Clinical examination revealed a fixed non-engaged fetal head (station −1), with a transverse posterior sagittal suture. A static three-dimensional volume was obtained by translabial ultrasound, offline analysis of which confirmed the clinical diagnosis of anterior asynclitism. Owing to the posterior twisting of the head towards the sacrum, the midline echo could only be obtained by cutting the volume with an oblique line, the direction of which was not perpendicular to the pubis as expected in cases of synclitic head. The sonographic appearance of the midline echo approaching the sacrum in a non-engaged transverse fetal head strongly supports the clinical suspicion of anterior asynclitism. PMID:21523842

  19. Management of head injuries in children.

    PubMed

    Conchie, Henry; Palmer, Sarah; Fernando, Katalin; Paul, Siba Prosad

    2016-07-01

    Head injury is the most common cause of injury-related death and permanent disability in children. Minor head trauma is common in childhood and does not require any medical treatment. Although deficits can occur even after mild to moderate head injury, they are markedly greater and become clinically evident following severe head injury. It is important that emergency department clinicians are aware of the signs and symptoms that indicate severe traumatic brain injury and triage for urgent intervention in those children who present with these signs and symptoms. Clinicians also need to know when children can be sent home with reassurance and information, and when they require admission or transfer to a neurosurgical unit. This article examines the literature on head injuries in children, describes assessment, management and treatment, and provides a simple management algorithm. PMID:27384805

  20. Natural convection around the human head.

    PubMed

    Clark, R P; Toy, N

    1975-01-01

    1. Factors determining the convective flow patterns around the human head in 'still' conditions are discussed in relation to body posture. 2. The flow patterns have been visualized using a schlieren optical system which reveals that the head has a thicker 'insulating' layer of convecting air in the erect posture than in the supine position. 3. Local convective and radiative heat transfer measurements from the head have been using surface calorimeters. These results are seen to be closely related to the thickness of the convective boundary layer flows. 4. The total convective and radiative heat loss from the head of a subject in the erect and supine position has been evaluated from the local measurements. For the head of the supine subject the heat loss was found to be 30% more than when the subject was standing. PMID:1142118

  1. Immunotherapy With MK-3475 in Surgically Resectable Head and Neck Squamous Cell Carcinoma

    ClinicalTrials.gov

    2016-07-11

    Cancer of Head and Neck; Head and Neck Cancer; Neoplasms, Head and Neck; Carcinoma, Squamous Cell of Head and Neck; Squamous Cell Carcinoma of the Head and Neck; Squamous Cell Carcinoma, Head and Neck

  2. Elbow dislocation with irreparable fracture radial head

    PubMed Central

    Tanna, Dilip

    2013-01-01

    Background: Treatment of elbow dislocation with irreparable radial head fracture needs replacement of radial head to achieve stability of elbow. An alternate method in cases of elbow dislocation with radial head fracture can be resection of radial head with repair of medial collateral ligament. We report a retrospective analysis of cases of elbow dislocation with irreparable radial head treated by excision head of radius and repair of MCL. Materials and Methods: Nine patients of elbow dislocation with associated irreparable fractures of the head of the radius were included in this analysis (6 F:3 M, Age: 35-47 years). Radial head excision was done through the lateral approach and MCL was sutured using no 3 Ethibond using medial approach. Above elbow plaster was given for 6 weeks and gradual mobilization was done thereafter. All patients were assessed at final followup using Mayo elbow performance score (MEPS). Results: Mean followup was 19.55 ± 7.12 months (range 14-36 months). There was no extension deficit when compared to opposite side with mean range of flexion of 138.8° ± 6.97° (range 130 -145°). Mean pronation was 87.7° ± 4.4° (range 80-90°) and mean supination was 87.7 ± 4.62° (range 80-90°). The mean MEPS was 98.8 ± 3.33 (range 90-100). No patient had pain, sensory complaints, subluxation or redislocation. All were able to carry out their daily activities without disability. Conclusion: Radial head excision with MCL repair is an acceptable option for treatment of patients with elbow dislocation and irreparable radial head fracture. PMID:23798760

  3. Sword-Like Trauma to the Shoulder with Open Head-Splitting Fracture of the Head

    PubMed Central

    Pantazis, Konstantinos; Iliopoulos, Ilias; Seferlis, Ioannis; Kokkalis, Zinon

    2016-01-01

    Head-splitting fractures occur as a result of violent compression of the head against the glenoid; the head splits and the tuberosities may remain attached to the fragments or split and separate. Isolated humeral head-splitting fractures are rare injuries. Favorable results with osteosynthesis can be difficult to achieve because of the very proximal location of the head fracture and associated poor vascularity. We present a case of a 67-year-old man who sustained a severe, sword-like trauma to his left shoulder after a road traffic accident with associated isolated open Gustilo-Anderson IIIA humeral head-splitting fracture. Bony union was achieved with minimal internal fixation but the clinical outcome deteriorated due to accompanying axillary nerve apraxia. To our knowledge, this type of sword-like injury with associated humeral head-split fracture has not previously been reported. PMID:27478665

  4. Heading in the right direction? An innovative approach toward proper patient head positioning

    SciTech Connect

    Grush, William H.; Steffen, Gary A

    2002-12-31

    An in-house-manufactured modification of the standard A-F foam rubber head-neck supports (aka. Timo Supports) was designed to eliminate clinical setup problems with head immobilization and instability during treatment, thus providing for a more comfortable head rest for the patient. The custom design of this head holder seeks to eliminate superior-to-inferior shift, and minimize the lateral right-to-left rotational movement of the head when coupled with an AquaPlast casting system. By focusing attention to the seating of the occipital portion of the head and contour of the patient's neck, the aforementioned problems of movement were addressed, while adhering to the interests of patient comfort in this modified head support system.

  5. Sword-Like Trauma to the Shoulder with Open Head-Splitting Fracture of the Head.

    PubMed

    Panagopoulos, Andreas; Pantazis, Konstantinos; Iliopoulos, Ilias; Seferlis, Ioannis; Kokkalis, Zinon

    2016-01-01

    Head-splitting fractures occur as a result of violent compression of the head against the glenoid; the head splits and the tuberosities may remain attached to the fragments or split and separate. Isolated humeral head-splitting fractures are rare injuries. Favorable results with osteosynthesis can be difficult to achieve because of the very proximal location of the head fracture and associated poor vascularity. We present a case of a 67-year-old man who sustained a severe, sword-like trauma to his left shoulder after a road traffic accident with associated isolated open Gustilo-Anderson IIIA humeral head-splitting fracture. Bony union was achieved with minimal internal fixation but the clinical outcome deteriorated due to accompanying axillary nerve apraxia. To our knowledge, this type of sword-like injury with associated humeral head-split fracture has not previously been reported. PMID:27478665

  6. "Stuttering" after minor head trauma.

    PubMed

    Strasberg, Stephen; Johnson, Elizabeth J; Parry, Thomas

    2016-03-01

    Traumatic brain injury (TBI) is defined as impairment in brain function as a result of mechanical force. It is classified based on clinical findings using the Glasgow Coma Scale (GCS). Mild TBI is defined as GCS 14-15; moderate, 9-13; and severe, 3-8. Patients with the same TBI classification may have very different underlying pathology. In moderate to severe TBI, the primary pathology may include contusions, hemorrhage, diffuse axonal injury, direct cellular damage, "tearing and shearing of the tissues, loss of the blood-brain barrier, disruption of the neurochemical homeostasis and loss of the electrochemical function". Although the primary pathology associated with mild TBI may be milder versions of the same pathology associated with moderate and severe TBI, it is generally a metabolic injury. However, it is reported that 15% of patients with mild TBI and a GCS score of 14 or 15 will have an intracranial lesion; less than 1% of these require neurosurgical intervention. Although patients with mild TBI may have intracranial lesions, it is rare that the presenting and only physical examination finding is an isolated neurologic finding. Here we present a case of isolated head trauma with a single physical examination finding--expressive aphasia. PMID:26371830

  7. An Experimental Device to Record Infant Head Movements.

    ERIC Educational Resources Information Center

    Jouen, Francois

    1981-01-01

    Analyzes methods used to record infant head position and the limits of these methods. An experimental device is proposed which records infant head turning and head righting when the vestibular system is stimulated. (Author/DB)

  8. Resonance of human brain under head acceleration

    PubMed Central

    Laksari, Kaveh; Wu, Lyndia C.; Kurt, Mehmet; Kuo, Calvin; Camarillo, David C.

    2015-01-01

    Although safety standards have reduced fatal head trauma due to single severe head impacts, mild trauma from repeated head exposures may carry risks of long-term chronic changes in the brain's function and structure. To study the physical sensitivities of the brain to mild head impacts, we developed the first dynamic model of the skull–brain based on in vivo MRI data. We showed that the motion of the brain can be described by a rigid-body with constrained kinematics. We further demonstrated that skull–brain dynamics can be approximated by an under-damped system with a low-frequency resonance at around 15 Hz. Furthermore, from our previous field measurements, we found that head motions in a variety of activities, including contact sports, show a primary frequency of less than 20 Hz. This implies that typical head exposures may drive the brain dangerously close to its mechanical resonance and lead to amplified brain–skull relative motions. Our results suggest a possible cause for mild brain trauma, which could occur due to repetitive low-acceleration head oscillations in a variety of recreational and occupational activities. PMID:26063824

  9. Resonance of human brain under head acceleration.

    PubMed

    Laksari, Kaveh; Wu, Lyndia C; Kurt, Mehmet; Kuo, Calvin; Camarillo, David C

    2015-07-01

    Although safety standards have reduced fatal head trauma due to single severe head impacts, mild trauma from repeated head exposures may carry risks of long-term chronic changes in the brain's function and structure. To study the physical sensitivities of the brain to mild head impacts, we developed the first dynamic model of the skull-brain based on in vivo MRI data. We showed that the motion of the brain can be described by a rigid-body with constrained kinematics. We further demonstrated that skull-brain dynamics can be approximated by an under-damped system with a low-frequency resonance at around 15 Hz. Furthermore, from our previous field measurements, we found that head motions in a variety of activities, including contact sports, show a primary frequency of less than 20 Hz. This implies that typical head exposures may drive the brain dangerously close to its mechanical resonance and lead to amplified brain-skull relative motions. Our results suggest a possible cause for mild brain trauma, which could occur due to repetitive low-acceleration head oscillations in a variety of recreational and occupational activities. PMID:26063824

  10. The compressive stiffness of human pediatric heads.

    PubMed

    Loyd, Andre Matthew; Nightingale, Roger W; Luck, Jason F; Song, Yin; Fronheiser, Lucy; Cutcliffe, Hattie; Myers, Barry S; Dale Bass, Cameron R

    2015-11-01

    Head injury is a persistent and costly problem for both children and adults. Globally, approximately 10 million people are hospitalized each year for head injuries. Knowing the structural properties of the head is important for modeling the response of the head in impact, and for providing insights into mechanisms of head injury. Hence, the goal of this study was to measure the sub-injurious structural stiffness of whole pediatric heads. 12 cadaveric pediatric (20-week-gestation to 16 years old) heads were tested in a battery of viscoelastic compression tests. The heads were compressed in both the lateral and anterior-posterior directions to 5% of gauge length at normalized deformation rates of 0.0005/s, 0.01/s, 0.1/s, and 0.3/s. Because of the non-linear nature of the response, linear regression models were used to calculate toe region (<2.5%) and elastic region (>2.5%) stiffness separately so that meaningful comparisons could be made across rate, age, and direction. The results showed that age was the dominant factor in predicting the structural stiffness of the human head. A large and statistically significant increase in the stiffness of both the toe region and the elastic region was observed with increasing age (p<0.0001), but no significant difference was seen across direction or normalized deformation rate. The stiffness of the elastic region increased from as low as 5 N/mm in the neonate to >4500 N/mm in the 16 year old. The changes in stiffness with age may be attributed to the disappearance of soft sutures and the thickening of skull bones with age. PMID:26476760

  11. Closed head trauma and aphasia1

    PubMed Central

    Heilman, Kenneth M.; Safran, Arthur; Geschwind, Norman

    1971-01-01

    A prospective study has been done on the relationship between closed head trauma and aphasia. The most frequent type of aphasia seen after closed head injury is an anomic aphasia. This aphasia is often associated with other defects of higher cortical function. The second most common type of aphasia is a Wernicke's aphasia. Other types of aphasia were not seen in this study. The areas of the head which when injured produce aphasia are the right orbitofrontal region and the left temporoparietal region. The prognosis for recovery appeared highly variable. PMID:5571313

  12. Achievements in rotary head magnetic recording

    NASA Astrophysics Data System (ADS)

    Mallinson, John C.

    1990-06-01

    The principal achievements since 1980 in rotary head recording on magnetic tape are outlined. These developments are related to fundamental improvements in recording media, heads, the design of tape transports, and signal processing. The D-1 and D-2 video tape recorders (VTRs), the Hi-Band 8-mm video cassette recorder (VCR), and the rotary digital audio tape (R-DAT) recorders are discussed. The future of rotary head recorders for consumer digital VCRs, professional high-definition TV (HDTV) VTRs, and consumer HDTV VCRs is assessed.

  13. Compact organic vapor jet printing print head

    DOEpatents

    Forrest, Stephen; McGraw, Gregory

    2016-02-02

    A first device is provided. The first device includes a print head, and a first gas source hermetically sealed to the print head. The print head further includes a first layer further comprising a plurality of apertures, each aperture having a smallest dimension of 0.5 to 500 microns. A second layer is bonded to the first layer. The second layer includes a first via in fluid communication with the first gas source and at least one of the apertures. The second layer is made of an insulating material.

  14. Compact organic vapor jet printing print head

    SciTech Connect

    Forrest, Stepehen R; McGraw, Gregory

    2015-01-27

    A first device is provided. The first device includes a print head, and a first gas source hermetically sealed to the print head. The print head further includes a first layer further comprising a plurality of apertures, each aperture having a smallest dimension of 0.5 to 500 microns. A second layer is bonded to the first layer. The second layer includes a first via in fluid communication with the first gas source and at least one of the apertures. The second layer is made of an insulating material.

  15. NSF Acting Head Mulls Job, Science Issues

    ERIC Educational Resources Information Center

    Zerkel, Fred H.

    1976-01-01

    Richard C. Atkinson, acting head of the National Science Foundation, gives his views on problems facing NSF and the science community and predicts growing support for basic research in the next decade. (MLH)

  16. Vacuum compatible miniature CCD camera head

    DOEpatents

    Conder, Alan D.

    2000-01-01

    A charge-coupled device (CCD) camera head which can replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating x-rays, such as within a target chamber where laser produced plasmas are studied. The camera head is small, capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, which allows for close(0.04" for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high energy density plasmas, for a variety of military industrial, and medical imaging applications.

  17. TMI-2 reactor vessel head removal

    SciTech Connect

    Bengel, P.R.; Smith, M.D.; Estabrook, G.A.

    1984-12-01

    This report describes the safe removal and storage of the Three Mile Island Unit 2 reactor vessel head. The head was removed in July 1984 to permit the removal of the plenum and the reactor core, which were damaged during the 1979 accident. From July 1982, plans and preparations were made using a standard head removal procedure modified by the necessary precautions and changes to account for conditions caused by the accident. After data acquisition, equipment and structure modifications, and training the head was safely removed and stored and the internals indexing fixture and a work platform were installed on top of the vessel. Dose rates during and after the operation were lower than expected; lessons were learned from the operation which will be applied to the continuing fuel removal operations activities.

  18. Head module control of mediator interactions.

    PubMed

    Takagi, Yuichiro; Calero, Guillermo; Komori, Hirofumi; Brown, Jesse A; Ehrensberger, Andreas H; Hudmon, Andy; Asturias, Francisco; Kornberg, Roger D

    2006-08-01

    Yeast Mediator proteins interacting with Med17(Srb4) have been expressed at a high level with the use of recombinant baculoviruses and recovered in homogeneous form as a seven subunit, 223 kDa complex. Electron microscopy and single-particle analysis identify this complex as the Mediator head module. The recombinant head module complements "headless" Mediator for the initiation of transcription in vitro. The module interacts with an RNA polymerase II-TFIIF complex, but not with the polymerase or TFIIF alone. This interaction is lost in the presence of a DNA template and associated RNA transcript, recapitulating the release of Mediator that occurs upon the initiation of transcription. Disruption of the head module in a temperature-sensitive mutant in vivo leads to the release of middle and tail modules from a transcriptionally active promoter. The head module evidently controls Mediator-RNA polymerase II and Mediator-promoter interactions. PMID:16885025

  19. Head Lice: Malathion Frequently Asked Questions

    MedlinePlus

    ... signs of infestation. Does malathion kill head lice eggs? Yes. The malathion lotion (Ovide*) available by prescription in the United States can kill some lice eggs. Back To Top *Use of trade names is ...

  20. Head and neck mucosal melanoma: a review.

    PubMed

    Lourenço, Silvia V; Fernandes, Juliana D; Hsieh, Ricardo; Coutinho-Camillo, Claudia M; Bologna, Sheyla; Sangueza, Martin; Nico, Marcello M S

    2014-07-01

    Head and neck mucosal melanoma (MM) is an aggressive and rare neoplasm of melanocytic origin. To date, few retrospective series and case reports have been reported on MM. This article reviews the current evidence on head and neck MM and the molecular pathways that mediate the pathogenesis of this disease. Head and neck MM accounts for 0.7%-3.8% of all melanomas and involve (in decreasing order of frequency) the sinonasal cavity, oral cavity, pharynx, larynx, and upper esophagus. Although many studies have examined MM of the head and neck and the underlying molecular pathways, individual genetic and molecular alterations were less investigated. Further studies are needed to complement existing data and to increase our understanding of melanocytes tumorigenesis. PMID:24423929

  1. [Minor Head Injury – a Silent Epidemic].

    PubMed

    Stocker, Reto; Letta, Claudio

    2016-05-11

    The vast majority out of the 20 000 patients annually hospitalized after sustaining a head injury belong to the minor head injury/cerebral concussion continuum. Fortunately, most of the patients show full recovery after days to weeks. However, about 15 % of these patients suffer from prolonged up to permanent sequels potentially impairing their quality of life to a considerable extent. This especially holds true for those who suffer from recurrent minor head injuries (i.e. victims from contact sport accidents). Unfortunately, many of these patients are never diagnosed in an appropriate way and therefore looked at as hypochondriacs or simulants. This prevents adequate rehabilitation and support. This review aims to present current knowledge about pathophysiology and clinical features of minor head injuries and to give some information about diagnostics and treatment according to current guidelines. PMID:27167479

  2. Ultrasound, normal fetus - head measurements (image)

    MedlinePlus

    ... Many health care providers like to have fetal measurements to verify the size of the fetus and ... any abnormalities. This ultrasound is of a head measurement, indicated by the cross hairs and dotted lines.

  3. Compressional head waves in attenuative formations

    SciTech Connect

    Liu, Q.H.; Chang, C.

    1994-12-31

    The attenuation of compressional head waves in a fluid-filled borehole is studied with the branch-cut integration method. The borehole fluid and solid formation are both assumed lossy with quality factors Q{sub f}({omega}) for the fluid, and Q{sub c}({omega}) and Q{sub s}({omega}) for the compressional and shear waves in the solid, respectively. The branch-cut integration method used in this work is an extension of that for a lossless medium. With this branch-cut integration method, the authors can isolate the groups of individual arrivals such as the compressional head waves and shear head waves, and study the attenuation of those particular wavefields in lossy media. This study, coupled with experimental work to be performed, may result in an effective way of measuring compressional head wave attenuation in the field.

  4. Heater head for a Stirling engine

    SciTech Connect

    Darooka, D.K.

    1988-09-06

    A heater head is described for a compound Stirling engine modules, each including a displacer cylinder coaxially aligned with the displacer cylinder of the other of the engine modules, a displacer piston mounted for reciprocation in the displacer cylinder.

  5. Drugs Approved for Head and Neck Cancer

    Cancer.gov

    This page lists cancer drugs approved by the Food and Drug Administration (FDA) for head and neck cancer. The list includes generic names and brand names. The drug names link to NCI’s Cancer Drug Information summaries.

  6. Repellency against head lice (Pediculus humanus capitis).

    PubMed

    Semmler, Margit; Abdel-Ghaffar, Fathy; Al-Rasheid, Khaled; Klimpel, Sven; Mehlhorn, Heinz

    2010-02-01

    The head louse problem increases at all levels of the international societies due to activities or life conditions that lead to often hair contacts among people. Lice occur exclusively on humans. Thus, they avoid dropping down from a head and therefore accept even a bad smelling hair of new a host. Due to this behaviour, there are only a few products on the markets which dare to claim a repellency activity that protects humans from infestation with head lice. The present study shows that a combination of an extract of the seeds of the plant Vitex agnus castus (monk pepper) and the compound paramenthan-3,8-diol (which is also found in some plants, e.g. Eucalyptus) act synergistically and are able to protect human hair for at least 7 h from invasion of head lice (Pediculus humanus capitis). The recently developed product containing both compounds is named Licatack Preventive Spray. PMID:20054562

  7. Treatment Alternatives Following Mild Head Injury.

    ERIC Educational Resources Information Center

    Novack, Thomas A.; And Others

    1988-01-01

    Discusses treatment alternatives which may alleviate problems in recovery following mild head injury, including providing education, cognitive stimulation, stress management training, individual counseling, group discussion, and physical activity in a day treatment setting. (Author/ABL)

  8. Intellectual Changes after Closed Head Injury

    ERIC Educational Resources Information Center

    Becker, Bruce

    1975-01-01

    This study provided more details on the nature of the intellectual deficit suffered by persons having closed head injuries and the recovery process as measured on the Wechsler Adult Intelligence Scale (WAIS). (Author/RK)

  9. Vacuum compatible miniature CCD camera head

    SciTech Connect

    Conder, A.D.

    2000-06-20

    A charge-coupled device (CCD) camera head is disclosed which can replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating x-rays, such as within a target chamber where laser produced plasmas are studied. The camera head is small, capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, which allows for close (0.04 inches for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high energy density plasmas, for a variety of military, industrial, and medical imaging applications.

  10. TMI-2 reactor vessel head removal

    SciTech Connect

    Bengel, P.R.; Smith, M.D.; Estabrook, G.A.

    1985-09-01

    This report describes the safe removal and storage of the Three Mile Island Unit 2 (TMI-2) reactor vessel head. The head was removed in July 1984 to permit the removal of the plenum and the reactor core, which were damaged during the 1979 accident. From July 1982, plans and preparations were made using a standard head removal procedure modified by the necessary precautions and changes to account for conditions caused by the accident. After data acquisition, equipment and structure modifications, and training, the head was safely removed and stored; and the internals indexing fixture and a work platform were installed on top of the vessel. Dose rates during and after the operation were lower than expected; lessons were learned from the operation which will be applied to the continuing fuel removal operations activities.

  11. Classification and management of mild head trauma

    PubMed Central

    Andrade, Almir F; Paiva, Wellingson S; Soares, Matheus S; De Amorim, Robson LO; Tavares, Wagner M; Teixeira, Manoel J

    2011-01-01

    Mild head trauma had been defined in patients with direct impact or deceleration effect admitted with a Glasgow Coma Scale score of 13–15. It is one of the most frequent causes of morbidity in emergency medicine. Although common, several controversies persist about its clinical management. In this paper, we describe the Brazilian guidelines for mild head trauma, based on a critical review of the relevant literature. PMID:21475628

  12. Neck injury response to direct head impact.

    PubMed

    Ivancic, Paul C

    2013-01-01

    Previous in vivo studies have observed flexion of the upper or upper/middle cervical spine and extension at inferior spinal levels due to direct head impacts. These studies hypothesized that hyperflexion may contribute to injury of the upper or middle cervical spine during real-life head impact. Our objectives were to determine the cervical spine injury response to direct head impact, document injuries, and compare our results with previously reported in vivo data. Our model consisted of a human cadaver neck (n=6) mounted to the torso of a rear impact dummy and carrying a surrogate head. Rearward force was applied to the model's forehead using a cable and pulley system and free-falling mass of 3.6kg followed by 16.7kg. High-speed digital cameras tracked head, vertebral, and pelvic motions. Average peak spinal rotations observed during impact were statistically compared (P<0.05) to physiological ranges obtained from intact flexibility tests. Peak head impact force was 249 and 504N for the 3.6 and 16.7kg free-falling masses, respectively. Occipital condyle loads reached 205.3N posterior shear, 331.4N compression, and 7.4Nm extension moment. We observed significant increases in intervertebral extension peaks above physiologic at C6/7 (26.3° vs. 5.7°) and C7/T1 (29.7° vs. 4.6°) and macroscopic ligamentous and osseous injuries at C6 through T1 due to the 504N impacts. Our results indicate that a rearward head shear force causes complex neck loads of posterior shear, compression, and extension moment sufficient to injure the lower cervical spine. Real-life neck injuries due to motor vehicle crashes, sports impacts, or falls are likely due to combined loads transferred to the neck by direct head impact and torso inertial loads. PMID:22613632

  13. 49 CFR 572.16 - Head.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 3-Year-Old Child § 572.16 Head. (a) The... SA 103C 002, sheet 8. (b) When the head is impacted by a test probe specified in § 572.21(a)(1) at 7... acceleration-time curve for this test is unimodal at or above the 50g level, and lies at or above that...

  14. Forced Fusion in Multisensory Heading Estimation

    PubMed Central

    de Winkel, Ksander N.; Katliar, Mikhail; Bülthoff, Heinrich H.

    2015-01-01

    It has been shown that the Central Nervous System (CNS) integrates visual and inertial information in heading estimation for congruent multisensory stimuli and stimuli with small discrepancies. Multisensory information should, however, only be integrated when the cues are redundant. Here, we investigated how the CNS constructs an estimate of heading for combinations of visual and inertial heading stimuli with a wide range of discrepancies. Participants were presented with 2s visual-only and inertial-only motion stimuli, and combinations thereof. Discrepancies between visual and inertial heading ranging between 0-90° were introduced for the combined stimuli. In the unisensory conditions, it was found that visual heading was generally biased towards the fore-aft axis, while inertial heading was biased away from the fore-aft axis. For multisensory stimuli, it was found that five out of nine participants integrated visual and inertial heading information regardless of the size of the discrepancy; for one participant, the data were best described by a model that explicitly performs causal inference. For the remaining three participants the evidence could not readily distinguish between these models. The finding that multisensory information is integrated is in line with earlier findings, but the finding that even large discrepancies are generally disregarded is surprising. Possibly, people are insensitive to discrepancies in visual-inertial heading angle because such discrepancies are only encountered in artificial environments, making a neural mechanism to account for them otiose. An alternative explanation is that detection of a discrepancy may depend on stimulus duration, where sensitivity to detect discrepancies differs between people. PMID:25938235

  15. Local scouring around L-head groynes

    NASA Astrophysics Data System (ADS)

    Dehghani, A. A.; Azamathulla, H. Md.; Hashemi Najafi, S. A.; Ayyoubzadeh, S. A.

    2013-11-01

    Groynes have been widely used to redirect the flow in channels and to protect eroding river banks. In general, groynes are more beneficial to aquatic habitat resources than other types of bank protection structures. One of the most important problems for designers is the estimation of maximum local scour depth in the vicinity of groynes. Due to constriction of flow area, a local velocity increased and scouring around the groyne is formed. From literatures, it can be seen that among various type of groynes, straight ones are more investigated; however, L-head groyne generally leads to larger sediment deposits between groynes, less scour at their head, and greater protection to the banks. An L-head groyne consists of parallel and perpendicular wall to flow direction. In this study, the maximum depth of scour around straight and L-head groynes is compared. Also, the effect of parallel wall angle (the angle between parallel and perpendicular walls) on maximum depth of scour was investigated and the optimal angle was determined. The results show that the maximum depth of scour around L-head groynes with parallel walls toward upstream direction is less than that of straight groynes. The distance to the thalweg line from the L-head groyne decreased compared to that of the straight groyne. The optimal angle for L-head groynes with a parallel wall in the downstream direction is found to be θ = 110° and for L-head groynes with parallel wall in the upstream direction is identified to be θ = 60°.

  16. Relative femoral head size in early hominids.

    PubMed

    Corruccini, R S; McHenry, H M

    1978-07-01

    Relative growth of the human femur head is studied by a logarithmic principal components method. Growth rates differ according to the population sampled and the other body dimensions being compared, and especially according to sex. The results do not support biomechanical assumptions of strongly positive allometry of the femur head, which have been used to argue that the australopithecine hip joint was not relatively small. PMID:98052

  17. Can imaginary head tilt shorten postrotatory nystagmus?

    NASA Technical Reports Server (NTRS)

    Gianna-Poulin, C. C.; Voelker, C. C.; Erickson, B.; Black, F. O.

    2001-01-01

    In healthy subjects, head tilt upon cessation of a constant-velocity yaw head rotation shortens the duration of postrotatory nystagmus. The presumed mechanism for this effect is that the velocity storage of horizontal semicircular canal inputs is being discharged by otolith organ inputs which signal a constant yaw head position when the head longitudinal axis is no longer earth-vertical. In the present study, normal subjects were rotated head upright in the dark on a vertical-axis rotational chair at 60 degrees/s for 75 s and were required to perform a specific task as soon as the chair stopped. Horizontal position of the right eye was recorded with an infra-red video camera. The average eye velocity (AEV) was measured over a 30-s interval following chair acceleration/deceleration. The ratios (postrotatory AEV/perrotatory AEV) were 1.1 (SD 0.112) when subjects (N=10) kept their head erect, 0.414 (SD 0.083) when subjects tilted their head forward, 1.003 (SD 0.108) when subjects imagined watching a TV show, 1.012 (SD 0.074) when subjects imagined looking at a painting on a wall, and 0.995 (SD 0.074) when subjects imagined floating in a prone position on a lake. Thus, while actual head tilt reduced postrotatory nystagmus, the imagination tasks did not have a statistically significant effect on postrotatory nystagmus. Therefore, velocity storage does not appear to be under the influence of cortical neural signals when subjects imagine that they are floating in a prone orientation.

  18. Head CT scan in Iranian minor head injury patients: evaluating current decision rules.

    PubMed

    Sadegh, Robab; Karimialavijeh, Ehsan; Shirani, Farzaneh; Payandemehr, Pooya; Bahramimotlagh, Hooman; Ramezani, Mahtab

    2016-02-01

    The objective of this study is to select one of the seven available clinical decision rules for minor head injury, for managing Iranian patients. This was a prospective cohort study evaluating medium- or high-risk minor head injury patients presenting to the Emergency Department. Patients with minor head trauma who were eligible for brain imaging based on seven available clinical decision rules (National Institute for Health and Clinical Excellence (NICE), National Emergency X-Radiography Utilization Study (NEXUS)-II, Neurotraumatology Committee of the World Federation of Neurosurgical Societies (NCWFNS), New Orleans, American College of Emergency Physicians (ACEP) Guideline, Scandinavian, and Canadian computed tomography (CT) head rule) were selected. Subjects were underwent a non-contrast axial spiral head CT scan. The outcome was defined as abnormal and normal head CT scan. Univariate analysis and stepwise linear regression were applied to show the best combination of risk factors for detecting CT scan abnormalities. Five hundred patients with minor head trauma were underwent brain CT scan. The following criteria were derived by stepwise linear regression: Glasgow Coma Scale (GCS) less than 15, confusion, signs of basal skull fracture, drug history of warfarin, vomiting more than once, loss of consciousness, focal neurologic deficit, and age over 65 years. This model has 86.15 % (75.33-93.45 %) sensitivity and 46.44 % (46.67-51.25 %) specificity in detecting minor head injury patients with CT scan abnormalities (95 % confidence interval). Of seven decision rules, only the Canadian CT Head Rule possesses seven of the eight high-risk factors associated with abnormal head CT results which were identified by this study. This study underlines the Canadian CT Head Rule's utility in Iranian minor head injury patients. Our study encourages researchers to evaluate available guidelines in different communities. PMID:26407978

  19. Electro-optic voltage sensor head

    DOEpatents

    Crawford, Thomas M.; Davidson, James R.; Woods, Gregory K.

    1999-01-01

    The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers.

  20. Electro-optic voltage sensor head

    DOEpatents

    Crawford, T.M.; Davidson, J.R.; Woods, G.K.

    1999-08-17

    The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers. 6 figs.

  1. Cold head maintenance with minimal service interruption

    NASA Astrophysics Data System (ADS)

    Radovinsky, A. L.; Michael, P. C.; Zhukovsky, A.; Forton, E.; Paradis, Y.; Nuttens, V.; Minervini, J. V.

    2015-12-01

    Turn-key superconducting magnet systems are increasingly conduction-cooled by cryogenerators. Gifford-McMahon systems are reliable and cost effective, but require annual maintenance. A usual method of servicing is replacing the cold head of the cryocooler. It requires a complicated design with a vacuum chamber separate from the main vacuum of the cryostat, as well as detachable thermal contacts, which add to the thermal resistance of the cooling heat path and reduce the reliability of the system. We present a rapid warm-up scheme to bring the cold head body, which remains rigidly affixed to the cold mass, to room temperature, while the cold mass remains at cryogenic temperature. Electric heaters thermally attached to the cold head stations are used to warm them up, which permits conventional cold head maintenance with no danger of contaminating the inside of the cold head body. This scheme increases the efficiency of the cooling system, facilitates annual maintenance of the cold head and returning the magnet to operation in a short time.

  2. Effect of heading perception on microsaccade dynamics.

    PubMed

    Piras, Alessandro; Raffi, Milena; Persiani, Michela; Perazzolo, Monica; Squatrito, Salvatore

    2016-10-01

    The present study shows the relationship between microsaccades and heading perception. Recent research demonstrates that microsaccades during fixation are necessary to overcome loss of vision due to continuous stimulation of the retinal receptors, even at the potential cost of a decrease in visual acuity. The goal of oculomotor fixational mechanisms might be not retinal stabilization, but controlled image motion adjusted to be optimal for visual processing. Thus, patterns of microsaccades may be exploited to help to understand the oculomotor system, aspects of visual perception, and the dynamics of visual attention. We presented an expansion optic flow in which the dot speed simulated a heading directed to the left or to the right of the subject, who had to signal the perceived heading by making a saccade toward the perceived direction. We recorded microsaccades during the optic flow stimulation to investigate their characteristics before and after the response. The time spent on heading perception was similar between right and left direction, and response latency was shorter during correct than incorrect responses. Furthermore, we observed that correct heading perception is associated with longer, larger and faster microsaccade characteristics. The time-course of microsaccade rate shows a modulation across the perception process similar to that seen for other local perception tasks, while the main direction is oriented toward the opposite side with respect to the perceived heading. Microsaccades enhance visual perception and, therefore, represent a fundamental motor process, with a specific effect for the build-up of global visual perception of space. PMID:27327105

  3. Videometric head tracker for augmented reality applications

    NASA Astrophysics Data System (ADS)

    Janin, Adam L.; Zikan, Karel; Mizell, David; Banner, Mike; Sowizral, Henry A.

    1995-12-01

    For the past three years, we have been developing augmented reality technology for application to a variety of touch labor tasks in aircraft manufacturing and assembly. The system would be worn by factory workers to provide them with better-quality information for performing their tasks than was previously available. Using a see-through head-mounted display (HMD) whose optics are set at a focal length of about 18 in., the display and its associated head tracking system can be used to superimpose and stabilize graphics on the surface of a work piece. This technology would obviate many expensive marking systems now used in aerospace manufacturing. The most challenging technical issue with respect to factory applications of AR is head position and orientation tracking. It requires high accuracy, long- range tracking in a high-noise environment. The approach we have chosen uses a head- mounted miniature video camera. The user's wearable computer system utilizes the camera to find fiducial markings that have been placed on known coordinates on or near the work piece. The system then computes the user's position and orientation relative to the fiducial marks. It is referred to as a `videometric' head tracker. In this paper, we describe the steps we took and the results we obtained in the process of prototyping our videometric head tracker, beginning with analytical and simulation results, and continuing through the working prototypes.

  4. What are Head Cavities? - A History of Studies on Vertebrate Head Segmentation.

    PubMed

    Kuratani, Shigeru; Adachi, Noritaka

    2016-06-01

    Motivated by the discovery of segmental epithelial coeloms, or "head cavities," in elasmobranch embryos toward the end of the 19th century, the debate over the presence of mesodermal segments in the vertebrate head became a central problem in comparative embryology. The classical segmental view assumed only one type of metamerism in the vertebrate head, in which each metamere was thought to contain one head somite and one pharyngeal arch, innervated by a set of cranial nerves serially homologous to dorsal and ventral roots of spinal nerves. The non-segmental view, on the other hand, rejected the somite-like properties of head cavities. A series of small mesodermal cysts in early Torpedo embryos, which were thought to represent true somite homologs, provided a third possible view on the nature of the vertebrate head. Recent molecular developmental data have shed new light on the vertebrate head problem, explaining that head mesoderm evolved, not by the modification of rostral somites of an amphioxus-like ancestor, but through the polarization of unspecified paraxial mesoderm into head mesoderm anteriorly and trunk somites posteriorly. PMID:27268975

  5. Development of age-specific Japanese head phantoms for dose evaluation in paediatric head CT examinations.

    PubMed

    Yamauchi-Kawaura, C; Fujii, K; Akahane, K; Yamauchi, M; Narai, K; Aoyama, T; Katsu, T; Obara, S; Imai, K; Ikeda, M

    2015-02-01

    In this study, the authors developed age-specific physical head phantoms simulating the physique of Japanese children for dose evaluation in paediatric head computed tomography (CT) examinations. Anatomical structures at 99 places in 0-, 0.5-, 1- and 3-y-old Japanese patients were measured using DICOM viewer software from CT images, and the head phantom of each age was designed. For trial manufacture, a 3-y-old head phantom consisting of acrylic resin and gypsum was produced by machine processing. Radiation doses for the head phantom were measured with radiophotoluminescence glass dosemeters and Si-pin photodiode dosemeters. To investigate whether the phantom shape was suitable for dose evaluation, organ doses in the same scan protocol were compared between the 3-y-old head and commercially available anthropomorphic phantoms having approximately the same head size. The doses of organs in both phantoms were equivalent. The authors' designed paediatric head phantom will be useful for dose evaluation in paediatric head CT examinations. PMID:24821932

  6. Head and neck injury risks in heavy metal: head bangers stuck between rock and a hard bass

    PubMed Central

    Patton, Declan

    2008-01-01

    Objective To investigate the risks of mild traumatic brain injury and neck injury associated with head banging, a popular dance form accompanying heavy metal music. Design Observational studies, focus group, and biomechanical analysis. Participants Head bangers. Main outcome measures Head Injury Criterion and Neck Injury Criterion were derived for head banging styles and both popular heavy metal songs and easy listening music controls. Results An average head banging song has a tempo of about 146 beats per minute, which is predicted to cause mild head injury when the range of motion is greater than 75°. At higher tempos and greater ranges of motion there is a risk of neck injury. Conclusion To minimise the risk of head and neck injury, head bangers should decrease their range of head and neck motion, head bang to slower tempo songs by replacing heavy metal with adult oriented rock, only head bang to every second beat, or use personal protective equipment. PMID:19091761

  7. 49 CFR 572.72 - Head assembly and test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Head assembly and test procedure. 572.72 Section... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 6-Year-Old Child § 572.72 Head assembly and test procedure. (a) Head assembly. The head consists of...

  8. Into Adulthood: A Study of the Effects of Head Start.

    ERIC Educational Resources Information Center

    Oden, Sherri; Schweinhart, Lawrence J.; Weikart, David P.

    This report describes the Long-Term Benefits of Head Start (LTBHS) study designed to address questions regarding the long-term effects of the Head Start program on the children and families served. Following the introduction, Chapter 2 presents a review of the research on Head Start, focusing on Head Start Planned Variation research, major…

  9. Kinematics of a Head-Neck Model Simulating Whiplash

    ERIC Educational Resources Information Center

    Colicchia, Giuseppe; Zollman, Dean; Wiesner, Hartmut; Sen, Ahmet Ilhan

    2008-01-01

    A whiplash event is a relative motion between the head and torso that occurs in rear-end automobile collisions. In particular, the large inertia of the head results in a horizontal translation relative to the thorax. This paper describes a simulation of the motion of the head and neck during a rear-end (whiplash) collision. A head-neck model that…

  10. Heading in Soccer: Integral Skill or Grounds for Cognitive Dysfunction?

    ERIC Educational Resources Information Center

    Kirkendall, Donald T.; Garrett, William E., Jr.

    2001-01-01

    Discusses how purposeful heading of soccer balls and head injuries affect soccer players' cognitive dysfunction. Cognitive deficits may occur for many reasons. Heading cannot be blamed when details of the actual event and impact are unknown. Concussions are the most common head injury in soccer and a factor in cognitive deficits and are probably…

  11. 28 CFR 71.39 - Appeal to authority head.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Appeal to authority head. 71.39 Section... Justice § 71.39 Appeal to authority head. (a) Any defendant who has filed a timely answer and who is... the authority head by filing a notice of appeal with the authority head in accordance with...

  12. 25 CFR 700.69 - Head of household.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Head of household. 700.69 Section 700.69 Indians THE... Policies and Instructions Definitions § 700.69 Head of household. (a) Household. A household is: (1) A... and is now legally divorced. (b) Head of household. The head of household is that individual...

  13. 49 CFR 179.220-8 - Tank heads.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Tank heads. 179.220-8 Section 179.220-8...-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-8 Tank heads. (a) Tank heads of the inner... dished or ellipsoidal for pressure on concave side. (b) Flanged and dished heads must have main...

  14. 22 CFR 35.39 - Appeal to authority head.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Appeal to authority head. 35.39 Section 35.39... Appeal to authority head. (a) Any defendant who has filed a timely answer and who is determined in an... head by filing a notice of appeal with the authority head in accordance with this section. (b)(1)...

  15. 29 CFR 1620.21 - Head of household.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 4 2014-07-01 2014-07-01 false Head of household. 1620.21 Section 1620.21 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION THE EQUAL PAY ACT § 1620.21 Head of household. Since a “head of household” or “head of family” status bears no relationship to...

  16. 45 CFR 79.39 - Appeal to authority head.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 1 2014-10-01 2014-10-01 false Appeal to authority head. 79.39 Section 79.39... REMEDIES § 79.39 Appeal to authority head. (a) Any defendant who has filed a timely answer and who is... the authority head by filing a notice of appeal with the authority head in accordance with...

  17. 22 CFR 35.39 - Appeal to authority head.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Appeal to authority head. 35.39 Section 35.39... Appeal to authority head. (a) Any defendant who has filed a timely answer and who is determined in an... head by filing a notice of appeal with the authority head in accordance with this section. (b)(1)...

  18. 48 CFR 218.271 - Head of contracting activity determinations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Head of contracting... Emergency Acquisition Flexibilities 218.271 Head of contracting activity determinations. For contract..., biological, chemical, or radiological attack, the term “head of the agency” is replaced with “head of...

  19. 28 CFR 71.39 - Appeal to authority head.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Appeal to authority head. 71.39 Section... Justice § 71.39 Appeal to authority head. (a) Any defendant who has filed a timely answer and who is... the authority head by filing a notice of appeal with the authority head in accordance with...

  20. 31 CFR 7.3 - Responsibilities of heads of offices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Responsibilities of heads of offices... INVENTIONS § 7.3 Responsibilities of heads of offices. (a) Heads of bureaus or offices in the Department... part. (b) Heads of bureaus or offices are responsible for obtaining from the employee the...

  1. 45 CFR 79.39 - Appeal to authority head.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Appeal to authority head. 79.39 Section 79.39... REMEDIES § 79.39 Appeal to authority head. (a) Any defendant who has filed a timely answer and who is... the authority head by filing a notice of appeal with the authority head in accordance with...

  2. 49 CFR 572.142 - Head assembly and test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Head assembly and test procedure. 572.142 Section...-year-Old Child Crash Test Dummy, Alpha Version § 572.142 Head assembly and test procedure. (a) The head assembly (refer to § 572.140(a)(1)(i)) for this test consists of the head (drawing 210-1000), adapter...

  3. 25 CFR 700.69 - Head of household.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Head of household. 700.69 Section 700.69 Indians THE... Policies and Instructions Definitions § 700.69 Head of household. (a) Household. A household is: (1) A... and is now legally divorced. (b) Head of household. The head of household is that individual...

  4. 28 CFR 71.39 - Appeal to authority head.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Appeal to authority head. 71.39 Section... Justice § 71.39 Appeal to authority head. (a) Any defendant who has filed a timely answer and who is... the authority head by filing a notice of appeal with the authority head in accordance with...

  5. 49 CFR 179.220-8 - Tank heads.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Tank heads. 179.220-8 Section 179.220-8...-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-8 Tank heads. (a) Tank heads of the inner... dished or ellipsoidal for pressure on concave side. (b) Flanged and dished heads must have main...

  6. 29 CFR 1620.21 - Head of household.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 4 2013-07-01 2013-07-01 false Head of household. 1620.21 Section 1620.21 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION THE EQUAL PAY ACT § 1620.21 Head of household. Since a “head of household” or “head of family” status bears no relationship to...

  7. 22 CFR 35.39 - Appeal to authority head.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Appeal to authority head. 35.39 Section 35.39... Appeal to authority head. (a) Any defendant who has filed a timely answer and who is determined in an... head by filing a notice of appeal with the authority head in accordance with this section. (b)(1)...

  8. 22 CFR 35.39 - Appeal to authority head.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Appeal to authority head. 35.39 Section 35.39... Appeal to authority head. (a) Any defendant who has filed a timely answer and who is determined in an... head by filing a notice of appeal with the authority head in accordance with this section. (b)(1)...

  9. 34 CFR 33.39 - Appeal to Department head.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 1 2012-07-01 2012-07-01 false Appeal to Department head. 33.39 Section 33.39... to Department head. (a) Any defendant who has filed a timely answer and who is determined in an... head by filing a notice of appeal with the Department head in accordance with this section. (b)(1)...

  10. 15 CFR 25.39 - Appeal to authority head.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false Appeal to authority head. 25.39... § 25.39 Appeal to authority head. (a) Any respondent who has filed a timely answer and who is... the authority head by filing a notice of appeal with the authority head in accordance with...

  11. 31 CFR 7.3 - Responsibilities of heads of offices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false Responsibilities of heads of offices... INVENTIONS § 7.3 Responsibilities of heads of offices. (a) Heads of bureaus or offices in the Department... part. (b) Heads of bureaus or offices are responsible for obtaining from the employee the...

  12. 45 CFR 79.39 - Appeal to authority head.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Appeal to authority head. 79.39 Section 79.39... REMEDIES § 79.39 Appeal to authority head. (a) Any defendant who has filed a timely answer and who is... the authority head by filing a notice of appeal with the authority head in accordance with...

  13. 5 CFR 185.139 - Appeal to authority head.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Appeal to authority head. 185.139 Section... FRAUD CIVIL REMEDIES § 185.139 Appeal to authority head. (a) Any defendant who has filed a timely answer... such decision to the authority head by filing a notice of appeal with the authority head in...

  14. 49 CFR 572.142 - Head assembly and test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly and test procedure. 572.142 Section...-year-Old Child Crash Test Dummy, Alpha Version § 572.142 Head assembly and test procedure. (a) The head assembly (refer to § 572.140(a)(1)(i)) for this test consists of the head (drawing 210-1000), adapter...

  15. 31 CFR 7.3 - Responsibilities of heads of offices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Responsibilities of heads of offices... INVENTIONS § 7.3 Responsibilities of heads of offices. (a) Heads of bureaus or offices in the Department... part. (b) Heads of bureaus or offices are responsible for obtaining from the employee the...

  16. 28 CFR 71.39 - Appeal to authority head.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Appeal to authority head. 71.39 Section... Justice § 71.39 Appeal to authority head. (a) Any defendant who has filed a timely answer and who is... the authority head by filing a notice of appeal with the authority head in accordance with...

  17. 48 CFR 218.271 - Head of contracting activity determinations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Head of contracting... Emergency Acquisition Flexibilities 218.271 Head of contracting activity determinations. For contract..., biological, chemical, or radiological attack, the term “head of the agency” is replaced with “head of...

  18. 5 CFR 185.139 - Appeal to authority head.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Appeal to authority head. 185.139 Section... FRAUD CIVIL REMEDIES § 185.139 Appeal to authority head. (a) Any defendant who has filed a timely answer... such decision to the authority head by filing a notice of appeal with the authority head in...

  19. 48 CFR 218.271 - Head of contracting activity determinations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Head of contracting... Emergency Acquisition Flexibilities 218.271 Head of contracting activity determinations. For contract..., biological, chemical, or radiological attack, the term “head of the agency” is replaced with “head of...

  20. 31 CFR 7.3 - Responsibilities of heads of offices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false Responsibilities of heads of offices... INVENTIONS § 7.3 Responsibilities of heads of offices. (a) Heads of bureaus or offices in the Department... part. (b) Heads of bureaus or offices are responsible for obtaining from the employee the...

  1. 48 CFR 218.270 - Head of contracting activity determinations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Head of contracting... Emergency Acquisition Flexibilities 218.270 Head of contracting activity determinations. For contract..., biological, chemical, or radiological attack, the term “head of the agency” is replaced with “head of...

  2. 15 CFR 25.39 - Appeal to authority head.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false Appeal to authority head. 25.39... § 25.39 Appeal to authority head. (a) Any respondent who has filed a timely answer and who is... the authority head by filing a notice of appeal with the authority head in accordance with...

  3. 45 CFR 79.39 - Appeal to authority head.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 1 2013-10-01 2013-10-01 false Appeal to authority head. 79.39 Section 79.39... REMEDIES § 79.39 Appeal to authority head. (a) Any defendant who has filed a timely answer and who is... the authority head by filing a notice of appeal with the authority head in accordance with...

  4. 29 CFR 1620.21 - Head of household.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Head of household. 1620.21 Section 1620.21 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION THE EQUAL PAY ACT § 1620.21 Head of household. Since a “head of household” or “head of family” status bears no relationship to...

  5. 49 CFR 179.220-8 - Tank heads.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Tank heads. 179.220-8 Section 179.220-8...-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-8 Tank heads. (a) Tank heads of the inner... dished or ellipsoidal for pressure on concave side. (b) Flanged and dished heads must have main...

  6. 25 CFR 700.69 - Head of household.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false Head of household. 700.69 Section 700.69 Indians THE... Policies and Instructions Definitions § 700.69 Head of household. (a) Household. A household is: (1) A... and is now legally divorced. (b) Head of household. The head of household is that individual...

  7. 29 CFR 1620.21 - Head of household.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 4 2011-07-01 2011-07-01 false Head of household. 1620.21 Section 1620.21 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION THE EQUAL PAY ACT § 1620.21 Head of household. Since a “head of household” or “head of family” status bears no relationship to...

  8. 15 CFR 25.39 - Appeal to authority head.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Appeal to authority head. 25.39... § 25.39 Appeal to authority head. (a) Any respondent who has filed a timely answer and who is... the authority head by filing a notice of appeal with the authority head in accordance with...

  9. 15 CFR 25.39 - Appeal to authority head.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Appeal to authority head. 25.39... § 25.39 Appeal to authority head. (a) Any respondent who has filed a timely answer and who is... the authority head by filing a notice of appeal with the authority head in accordance with...

  10. 34 CFR 33.39 - Appeal to Department head.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 1 2011-07-01 2011-07-01 false Appeal to Department head. 33.39 Section 33.39... to Department head. (a) Any defendant who has filed a timely answer and who is determined in an... head by filing a notice of appeal with the Department head in accordance with this section. (b)(1)...

  11. 29 CFR 1620.21 - Head of household.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 4 2012-07-01 2012-07-01 false Head of household. 1620.21 Section 1620.21 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION THE EQUAL PAY ACT § 1620.21 Head of household. Since a “head of household” or “head of family” status bears no relationship to...

  12. 5 CFR 185.139 - Appeal to authority head.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Appeal to authority head. 185.139 Section... FRAUD CIVIL REMEDIES § 185.139 Appeal to authority head. (a) Any defendant who has filed a timely answer... such decision to the authority head by filing a notice of appeal with the authority head in...

  13. 31 CFR 7.3 - Responsibilities of heads of offices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false Responsibilities of heads of offices... INVENTIONS § 7.3 Responsibilities of heads of offices. (a) Heads of bureaus or offices in the Department... part. (b) Heads of bureaus or offices are responsible for obtaining from the employee the...

  14. 45 CFR 79.39 - Appeal to authority head.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Appeal to authority head. 79.39 Section 79.39... REMEDIES § 79.39 Appeal to authority head. (a) Any defendant who has filed a timely answer and who is... the authority head by filing a notice of appeal with the authority head in accordance with...

  15. 49 CFR 179.220-8 - Tank heads.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Tank heads. 179.220-8 Section 179.220-8...-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-8 Tank heads. (a) Tank heads of the inner... dished or ellipsoidal for pressure on concave side. (b) Flanged and dished heads must have main...

  16. 25 CFR 700.69 - Head of household.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false Head of household. 700.69 Section 700.69 Indians THE... Policies and Instructions Definitions § 700.69 Head of household. (a) Household. A household is: (1) A... and is now legally divorced. (b) Head of household. The head of household is that individual...

  17. 5 CFR 185.139 - Appeal to authority head.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Appeal to authority head. 185.139 Section... FRAUD CIVIL REMEDIES § 185.139 Appeal to authority head. (a) Any defendant who has filed a timely answer... such decision to the authority head by filing a notice of appeal with the authority head in...

  18. 49 CFR 179.400-7 - Tank heads.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Tank heads. 179.400-7 Section 179.400-7...-7 Tank heads. (a) Tank heads of the inner tank and outer jacket must be flanged and dished, or ellipsoidal. (b) Flanged and dished heads must have— (1) A main inside dish radius not greater than...

  19. 22 CFR 35.39 - Appeal to authority head.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Appeal to authority head. 35.39 Section 35.39... Appeal to authority head. (a) Any defendant who has filed a timely answer and who is determined in an... head by filing a notice of appeal with the authority head in accordance with this section. (b)(1)...

  20. 25 CFR 700.69 - Head of household.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Head of household. 700.69 Section 700.69 Indians THE... Policies and Instructions Definitions § 700.69 Head of household. (a) Household. A household is: (1) A... and is now legally divorced. (b) Head of household. The head of household is that individual...

  1. 21 CFR 892.1920 - Radiographic head holder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiographic head holder. 892.1920 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1920 Radiographic head holder. (a) Identification. A radiographic head holder is a device intended to position the patient's head during...

  2. 45 CFR 1311.1 - Head Start Fellows Program Purpose.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 4 2012-10-01 2012-10-01 false Head Start Fellows Program Purpose. 1311.1 Section... SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION FOR CHILDREN, YOUTH AND FAMILIES, HEAD START PROGRAM HEAD START FELLOWS PROGRAM § 1311.1 Head Start Fellows Program Purpose. (a) This...

  3. 34 CFR 33.39 - Appeal to Department head.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 1 2014-07-01 2014-07-01 false Appeal to Department head. 33.39 Section 33.39... to Department head. (a) Any defendant who has filed a timely answer and who is determined in an... head by filing a notice of appeal with the Department head in accordance with this section. (b)(1)...

  4. 15 CFR 25.39 - Appeal to authority head.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Appeal to authority head. 25.39... § 25.39 Appeal to authority head. (a) Any respondent who has filed a timely answer and who is... the authority head by filing a notice of appeal with the authority head in accordance with...

  5. 28 CFR 71.39 - Appeal to authority head.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Appeal to authority head. 71.39 Section... Justice § 71.39 Appeal to authority head. (a) Any defendant who has filed a timely answer and who is... the authority head by filing a notice of appeal with the authority head in accordance with...

  6. 34 CFR 33.39 - Appeal to Department head.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 1 2013-07-01 2013-07-01 false Appeal to Department head. 33.39 Section 33.39... to Department head. (a) Any defendant who has filed a timely answer and who is determined in an... head by filing a notice of appeal with the Department head in accordance with this section. (b)(1)...

  7. 48 CFR 218.271 - Head of contracting activity determinations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Head of contracting... Emergency Acquisition Flexibilities 218.271 Head of contracting activity determinations. For contract..., biological, chemical, or radiological attack, the term “head of the agency” is replaced with “head of...

  8. Head injuries: a study evaluating the impact of the NICE head injury guidelines

    PubMed Central

    Hassan, Z; Smith, M; Littlewood, S; Bouamra, O; Hughes, D; Biggin, C; Amos, K; Mendelow, A; Lecky, F

    2005-01-01

    Background: The NICE head injury guidelines recommend a different approach in the management of head injury patients. It suggests that CT head scan should replace skull x ray (SXR) and observation/admission as the first investigation. We wished to determine the impact of NICE on SXR, CT scan, and admission on all patients with head injury presenting to the ED setting and estimate the cost effectiveness of these guidelines, which has not been quantified to date. Design: Study of head injury patients presenting to two EDs before and after implementation of NICE guidelines Methods: The rate of SXR, CT scan, and admission were determined six months before and one month after NICE implementation in both centres. The before study also looked at predicted rates had NICE been applied. This enabled predicted and actual cost effectiveness to be determined. Result: 1130 patients with head injury were studied in four 1 month periods (two in each centre). At the teaching hospital, the CT head scan rate more than doubled (3% to 7%), the SXR declined (37% to 4%), while the admission rate more than halved (9% to 4%). This represented a saving of £3381 per 100 head injury patients: greater than predicted with no adverse events. At the District General Hospital, the CT head scan rate more than quadrupled (1.4% to 9%), the SXR dropped (19 to 0.57%), while the admission rate declined (7% to 5%). This represented a saving of £290 per 100 head injury patients: less than predicted. Conclusion: The implementation of the NICE guidelines led to a two to fivefold increase in the CT head scan rate depending on the cases and baseline departmental practice. However, the reduction in SXR and admission appears to more than offset these costs without compromising patient outcomes. PMID:16299190

  9. Predictors of Positive Head CT Scan and Neurosurgical Procedures After Minor Head Trauma

    PubMed Central

    Kisat, Mehreen; Zafar, Syed Nabeel; Latif, Asad; Villegas, Cassandra V.; Efron, David T.; Stevens, Kent A.; Haut, Elliott R; Schneider, Eric B.; Zafar, Hasnain; Haider, Adil H.

    2012-01-01

    Background There continues to be an ongoing debate regarding the utility of Head CT scans in patients with a normal Glasgow Coma Scale (GCS) after minor head injury. The objective of this study is to determine patient and injury characteristics that predict a positive head CT scan or need for a Neurosurgical Procedure (NSP) among patients with blunt head injury and a normal GCS. Materials and Methods Retrospective analysis of adult patients in the National Trauma Data Bank who presented to the ED with a history of blunt head injury and a normal GCS of 15. The primary outcomes were a positive head CT scan or a NSP. Multivariate logistic regression controlling for patient and injury characteristics was used to determine predictors of each outcome. Results Out of a total of 83,566 patients, 24,414 (29.2%) had a positive head CT scan and 3,476 (4.2%) underwent a NSP. Older patients and patients with a history of fall (as compared to a motor vehicle crash) were more likely to have a positive finding on a head CT scan. Male patients, African-Americans (as compared to Caucasians) and those who presented with a fall were more likely to have a NSP. Conclusions Older age, male gender, ethnicity and mechanism of injury are significant predictors of a positive finding on head CT scans and the need for neurosurgical procedures. This study highlights patient and injury specific characteristics that may help in identifying patients with supposedly minor head injury who will benefit from a head CT scan. PMID:21872271

  10. [Hygienic aspects of pig's head meat. 1. Obtaining and processing pigs' heads].

    PubMed

    Bijker, P G; Koolmees, P A

    1988-05-01

    Pigs's head meat is mainly obtained in specialised deboning plants and provides raw materials for the manufacture of meat products and snacks. Few data on hygiene in processing and production of pig's heads or on the bacteriological quality and tissue composition of pig's head meat have so far been published. The object of the present investigation was to supplement these data and to examine the extent to which this quality could be improved by Good Manufacturing Practices (GMP's). A total number of 11 slaughter-houses and 14 deboning plants were studied. Hygiene was assessed by two investigators on the basis of a check list. Temperatures of rooms, heads and head meat were measured. Twenty-one samples (7 x 3) were taken in each of nine deboning plants for bacteriological and histological examination. The investigations carried out in slaughter-houses showed that pig's heads were only washed in five out of eleven slaughter-houses. Cleansing and disinfection of the apparatus used in splitting the carcasses were omitted or merely carried out incidentally during slaughter. Assessment of hygiene in the deboning plants ranged from adequate to satisfactory in 13 out of 14 plants. The average aerobic colony count in Log N g-1 of pig's head meat was 6.7 +/- 0.7; this was 4.4 +/- 0.9 for counts of colony-forming units (CFU) of Enterobacteriaceae. Tonsils, mucous membranes, bone, hair and dirt were found to be present in 8, 13, 21, 39 and 9 per cent of the samples respectively. As a result of the manual cleavage of heads, relatively large bone particles (greater than 8 mm) were detected in the head meat. It is concluded that an improvement of the hygienic quality of pig's head meat can mainly be achieved by taking more care in obtaining pig's heads. PMID:3287680

  11. The Effects of Head Start Health Services: Executive Summary of the Head Start Health Evaluation.

    ERIC Educational Resources Information Center

    Fosburg, Linda B.; And Others

    This report summarizes findings of an evaluation of Head Start health services. Chapter one presents an overview of the background of the evaluation project. Chapter two highlights findings for the major evaluation questions. These questions focus specifically on children's health status prior to entry into Head Start, health services subsequently…

  12. The Head to Head That Had to Happen: A Case Study of Television Sport and Entrepreneurship.

    ERIC Educational Resources Information Center

    Whannel, Garry

    The race between Mary Decker and Zola Budd, a head to head confrontation in the 1985 Olympic Games, is examined within the broader context of the transformation taking place in sports as a result of the combined efforts of television and the economic forces of sponsorship. Athletics is going through this process of transformation both economically…

  13. Head Rotation Detection in Marmoset Monkeys

    NASA Astrophysics Data System (ADS)

    Simhadri, Sravanthi

    Head movement is known to have the benefit of improving the accuracy of sound localization for humans and animals. Marmoset is a small bodied New World monkey species and it has become an emerging model for studying the auditory functions. This thesis aims to detect the horizontal and vertical rotation of head movement in marmoset monkeys. Experiments were conducted in a sound-attenuated acoustic chamber. Head movement of marmoset monkey was studied under various auditory and visual stimulation conditions. With increasing complexity, these conditions are (1) idle, (2) sound-alone, (3) sound and visual signals, and (4) alert signal by opening and closing of the chamber door. All of these conditions were tested with either house light on or off. Infra-red camera with a frame rate of 90 Hz was used to capture of the head movement of monkeys. To assist the signal detection, two circular markers were attached to the top of monkey head. The data analysis used an image-based marker detection scheme. Images were processed using the Computation Vision Toolbox in Matlab. The markers and their positions were detected using blob detection techniques. Based on the frame-by-frame information of marker positions, the angular position, velocity and acceleration were extracted in horizontal and vertical planes. Adaptive Otsu Thresholding, Kalman filtering and bound setting for marker properties were used to overcome a number of challenges encountered during this analysis, such as finding image segmentation threshold, continuously tracking markers during large head movement, and false alarm detection. The results show that the blob detection method together with Kalman filtering yielded better performances than other image based techniques like optical flow and SURF features .The median of the maximal head turn in the horizontal plane was in the range of 20 to 70 degrees and the median of the maximal velocity in horizontal plane was in the range of a few hundreds of degrees per

  14. 49 CFR 179.100-8 - Tank heads.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Tank heads. 179.100-8 Section 179.100-8... Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100-8 Tank heads. (a) The tank head shape... adjacent to the head and the minor axis shall be one-half the major axis. (b) Each tank head made...

  15. 49 CFR 179.100-8 - Tank heads.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Tank heads. 179.100-8 Section 179.100-8... Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100-8 Tank heads. (a) The tank head shape... adjacent to the head and the minor axis shall be one-half the major axis. (b) Each tank head made...

  16. 49 CFR 179.100-8 - Tank heads.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Tank heads. 179.100-8 Section 179.100-8... Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100-8 Tank heads. (a) The tank head shape... adjacent to the head and the minor axis shall be one-half the major axis. (b) Each tank head made...

  17. 49 CFR 179.100-8 - Tank heads.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Tank heads. 179.100-8 Section 179.100-8... Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100-8 Tank heads. (a) The tank head shape... adjacent to the head and the minor axis shall be one-half the major axis. (b) Each tank head made...

  18. GPS Position and Heading Circuitry for Ships

    NASA Technical Reports Server (NTRS)

    Cooke, Michael P.; Yim, Hester J.; Gomez, Susan F.

    2003-01-01

    Circuit boards that contain radio-frequency (RF) and digital circuitry have been developed by NASA to satisfy a requirement of the Port of Houston Authority for relatively inexpensive Global Positioning System (GPS) receivers that indicate the azimuthal headings as well as the positions of ships. The receiver design utilizes the unique architecture of the Mitel commercial chip-set, which provides for an accurate GPS-based heading-determination device. The major components include two RF front ends (each connected to a separate antenna), a surface-acoustic-wave intermediate-frequency filter between second- and third-stage mixers, a correlator, and a reduced-instruction- set computer. One of the RF front ends operates as a master, the other as a slave. Both RF front ends share a 10-MHz sinusoidal clock oscillator, which provides for more accurate carrier phase measurements between the two antennas. The outputs of the RF front ends are subjected to conventional GPS processing. The commercial-based chip-set design approach provides an inexpensive open architecture GPS platform, which can be used in developing and implementing unique GPS-heading and attitude-determination algorithms for specific applications. The heading is estimated from the GPS position solutions of the two antennas by an algorithm developed specifically for this application. If a third (and preferably a fourth) antenna were added, it would be possible to estimate the attitude of the GPS receiver in three dimensions instead of only its heading in a horizontal plane.

  19. Aspects of abuse: abusive head trauma.

    PubMed

    Hinds, Tanya; Shalaby-Rana, Eglal; Jackson, Allison M; Khademian, Zarir

    2015-03-01

    Abusive Head Trauma (AHT) is a form of child physical abuse that involves inflicted injury to the brain and its associated structures. Abusive Head Trauma, colloquially called Shaken Baby Syndrome, is the most common cause of serious or fatal brain injuries in children aged 2 years and younger. The American Academy of Pediatrics recommends the term Abusive Head Trauma, as opposed to Shaken Baby Syndrome, as the former term encompasses multiple forms of inflicted head injury (inertial, contact, and hypoxic-ischemic) and a range of clinical presentations and radiologic findings and their sequelae. Children diagnosed with AHT are 5 times more likely to die compared with accidentally head-injured children, yet signs and symptoms are not always obvious, and therefore the diagnosis can be overlooked. Therefore, the American Academy of Pediatrics has tasked pediatricians with knowing how and when to begin an evaluation of children with signs and symptoms that could possibly be due to AHT. Overall, a detailed history of present illness and medical history, recognition of physical and radiological findings, and careful interpretation of retinal pathology are important aspects of formulating the differential diagnoses and increasing or decreasing the index of suspicion for AHT. PMID:25771265

  20. Architecture of the Mediator head module.

    PubMed

    Imasaki, Tsuyoshi; Calero, Guillermo; Cai, Gang; Tsai, Kuang-Lei; Yamada, Kentaro; Cardelli, Francesco; Erdjument-Bromage, Hediye; Tempst, Paul; Berger, Imre; Kornberg, Guy Lorch; Asturias, Francisco J; Kornberg, Roger D; Takagi, Yuichiro

    2011-07-14

    Mediator is a key regulator of eukaryotic transcription, connecting activators and repressors bound to regulatory DNA elements with RNA polymerase II (Pol II). In the yeast Saccharomyces cerevisiae, Mediator comprises 25 subunits with a total mass of more than one megadalton (refs 5, 6) and is organized into three modules, called head, middle/arm and tail. Our understanding of Mediator assembly and its role in regulating transcription has been impeded so far by limited structural information. Here we report the crystal structure of the essential Mediator head module (seven subunits, with a mass of 223 kilodaltons) at a resolution of 4.3 ångströms. Our structure reveals three distinct domains, with the integrity of the complex centred on a bundle of ten helices from five different head subunits. An intricate pattern of interactions within this helical bundle ensures the stable assembly of the head subunits and provides the binding sites for general transcription factors and Pol II. Our structural and functional data suggest that the head module juxtaposes transcription factor IIH and the carboxy-terminal domain of the largest subunit of Pol II, thereby facilitating phosphorylation of the carboxy-terminal domain of Pol II. Our results reveal architectural principles underlying the role of Mediator in the regulation of gene expression. PMID:21725323

  1. Geometric Morphometrics of Rodent Sperm Head Shape

    PubMed Central

    Varea Sánchez, María; Bastir, Markus; Roldan, Eduardo R. S.

    2013-01-01

    Mammalian spermatozoa, particularly those of rodent species, are extremely complex cells and differ greatly in form and dimensions. Thus, characterization of sperm size and, particularly, sperm shape represents a major challenge. No consensus exists on a method to objectively assess size and shape of spermatozoa. In this study we apply the principles of geometric morphometrics to analyze rodent sperm head morphology and compare them with two traditional morphometry methods, that is, measurements of linear dimensions and dimensions-derived parameters calculated using formulae employed in sperm morphometry assessments. Our results show that geometric morphometrics clearly identifies shape differences among rodent spermatozoa. It is also capable of discriminating between size and shape and to analyze these two variables separately. Thus, it provides an accurate method to assess sperm head shape. Furthermore, it can identify which sperm morphology traits differ between species, such as the protrusion or retraction of the base of the head, the orientation and relative position of the site of flagellum insertion, the degree of curvature of the hook, and other distinct anatomical features and appendices. We envisage that the use of geometric morphometrics may have a major impact on future studies focused on the characterization of sperm head formation, diversity of sperm head shape among species (and underlying evolutionary forces), the effects of reprotoxicants on changes in cell shape, and phenotyping of genetically-modified individuals. PMID:24312234

  2. Heat exchanger, head and shell acceptance criteria

    SciTech Connect

    Lam, P.S.; Sindelar, R.L.

    1992-09-01

    Instability of postulated flaws in the head component of the heat exchanger could not produce a large break, equivalent to a DEGB in the PWS piping, due to the configuration of the head and restraint provided by the staybolts. Rather, leakage from throughwall flaws in the head would increase with flaw length with finite leakage areas that are bounded by a post-instability flaw configuration. Postulated flaws at instability in the shell of the heat exchanger or in the cooling water nozzles could produce a large break in the Cooling Water System (CWS) pressure boundary. An initial analysis of flaw stability for postulated flaws in the heat exchanger head was performed in January 1992. This present report updates that analysis and, additionally, provides acceptable flaw configurations to maintain defined structural or safety margins against flaw instability of the external pressure boundary components of the heat exchanger, namely the head, shell, and cooling water nozzles. Structural and flaw stability analyses of the heat exchanger tubes, the internal pressure boundary of the heat exchangers or interface boundary between the PWS and CWS, were previously completed in February 1992 as part of the heat exchanger restart evaluation and are not covered in this report.

  3. Acceptance criteria for heat exchanger head staybolts

    SciTech Connect

    Sindelar, R.L.; Lam, P.S.; Barnes, D.M.; Placr, A.; Morrison, J.M.

    1991-01-01

    Each of the six primary coolant loop systems of the Savannah River Site production reactors contains two parallel single-pass heat exchangers to transfer heat from the primary coolant (D{sub 2}O) to the secondary cooling water (H{sub 2}O). The configuration of the heat exchangers includes a plenary space defined by the heat exchanger tubesheet and the heat exchanger head at both the heat exchanger inlet and outlet to the primary piping. The primary restraint of the heat exchanger head (Type 304 stainless steel) is provided by 84 staybolts (Type 303 stainless steel) which attach to the tubesheet. The staybolts were cap seal-welded in the mid-1960's and are immersed in moderator. Access to inspect the staybolts is limited to a recently-developed ultrasonic technique shooting a beam through the staybolt assembly. Acceptance Criteria to allow disposition of flaws detected by UT inspection have been developed. The structural adequacy to protect against collapse loading of the head is demonstrated by finite element analysis of the head assembly and fracture analysis of flaw postulates in the staybolts. Both normal operation and normal operation plus seismic loading conditions were considered. Several bounding cases containing various configurations of nonactive (exceeding critical flaw size) staybolts were analyzed. The model of the head assembly can be applied to evaluate any active staybolt configurations based on the results from future inspections. 9 refs.

  4. Acceptance criteria for heat exchanger head staybolts

    SciTech Connect

    Sindelar, R.L.; Lam, P.S.; Barnes, D.M.; Placr, A.; Morrison, J.M.

    1991-12-31

    Each of the six primary coolant loop systems of the Savannah River Site production reactors contains two parallel single-pass heat exchangers to transfer heat from the primary coolant (D{sub 2}O) to the secondary cooling water (H{sub 2}O). The configuration of the heat exchangers includes a plenary space defined by the heat exchanger tubesheet and the heat exchanger head at both the heat exchanger inlet and outlet to the primary piping. The primary restraint of the heat exchanger head (Type 304 stainless steel) is provided by 84 staybolts (Type 303 stainless steel) which attach to the tubesheet. The staybolts were cap seal-welded in the mid-1960`s and are immersed in moderator. Access to inspect the staybolts is limited to a recently-developed ultrasonic technique shooting a beam through the staybolt assembly. Acceptance Criteria to allow disposition of flaws detected by UT inspection have been developed. The structural adequacy to protect against collapse loading of the head is demonstrated by finite element analysis of the head assembly and fracture analysis of flaw postulates in the staybolts. Both normal operation and normal operation plus seismic loading conditions were considered. Several bounding cases containing various configurations of nonactive (exceeding critical flaw size) staybolts were analyzed. The model of the head assembly can be applied to evaluate any active staybolt configurations based on the results from future inspections. 9 refs.

  5. Autofocus module for multilaser print heads

    NASA Astrophysics Data System (ADS)

    Zambuto, James J.

    1998-12-01

    Polaroid's Optical Engineering Department has developed an autofocus module designed for use with Polaroid's multi-laser print head. The print head and focus module are now being manufactured and sold as part of a high-quality laser printer for 14' X 17' medical diagnostic images. The focus module is mated and aligned to a cylinder that is clamped into a V on the print head to utilize the semi-kinematic methodology of the print head. The printer clamps the film onto an external drum that is spun at 3300 RPM. While being spun, the profile of the film is 350 micrometer peak to valley. The print head's focus tolerance is plus or minus 5 micrometer, which is a consequence of using binary film, laser diodes, and the required gray scale. A moving objective lens that tracks the film based on real-time focus information is needed. Polaroid has developed a new focus sensor and assembly process that is economical, reliable and simple. The new sensor can be assembled in 15 minutes and replaces a more complicated design.

  6. Rotation axes of the head during positioning, head shaking, and locomotion.

    PubMed

    Kunin, Mikhail; Osaki, Yasuhiro; Cohen, Bernard; Raphan, Theodore

    2007-11-01

    Static head orientations obey Donders' law and are postulated to be rotations constrained by a Fick gimbal. Head oscillations can be voluntary or generated during natural locomotion. Whether the rotation axes of the voluntary oscillations or during locomotion are constrained by the same gimbal is unknown and is the subject of this study. Head orientation was monitored with an Optotrak (Northern Digital). Human subjects viewed visual targets wearing pin-hole goggles to achieve static head positions with the eyes centered in the orbit. Incremental rotation axes were determined for pitch and yaw by computing the velocity vectors during head oscillation and during locomotion at 1.5 m/s on a treadmill. Static head orientation could be described by a generalization of the Fick gimbal by having the axis of the second rotation rotate by a fraction, k, of the angle of the first rotation without a third rotation. We have designated this as a k-gimbal system. Incremental rotation axes for both pitch and yaw oscillations were functions of the pitch but not the yaw head positions. The pivot point for head oscillations was close to the midpoint of the interaural line. During locomotion, however, the pivot point was considerably lower. These findings are well explained by an implementation of the k-gimbal model, which has a rotation axis superimposed on a Fick-gimbal system. This could be realized physiologically by the head interface with the dens and occipital condyles during head oscillation with a contribution of the lower spine to pitch during locomotion. PMID:17898142

  7. Effect of clenching with a mouthguard on head acceleration during heading of a soccer ball.

    PubMed

    Narimatsu, Keishiro; Takeda, Tomotaka; Nakajima, Kazunori; Konno, Michiyo; Ozawa, Takamitsu; Ishigami, Keiichi

    2015-01-01

    Concussions are acceleration-deceleration injuries that occur when biomechanical forces are transmitted to the cerebral tissues. By limiting acceleration of the head, enhanced cervical muscle activity derived from clenching with a mouthguard (MG) may reduce the incidence or severity of concussions following impact. The purpose of this study was to investigate the effect of voluntary clenching with a proper MG on acceleration of the head during "heading" of a soccer ball. Eleven male high school soccer players (mean age, 16.8 years) participated in the study. Each player was given a customized MG. An automated soccer machine was used to project the ball at the participants at a constant speed. The participants headed the ball under 3 different oral conditions: drill 1, heading freely performed without instruction and without the MG; drill 2, heading performed as the subject was instructed to clench the masseter muscles tightly while not wearing the MG; drill 3, heading performed as the subject was instructed to clench tightly while wearing the MG. Each participant repeated each drill 5 times. Linear acceleration of the head was measured with a 3-axis accelerometer. Activity of the masseter and sternocleidomastoid muscles was measured by wireless electromyography. Weak masseter and sternocleidomastoid muscle activity was observed during drill 1. After the soccer players had been instructed to clench their masseter muscles (drills 2 and 3), statistically significant decreases in head acceleration and increases in masseter and sternocleidomastoid muscle activity were observed (P < 0.05; paired t test). The effect was stronger when the players wore the MG. Dentists should encourage soccer players to habitually clench while wearing a proper mouthguard to strengthen cervical muscle resistance as a way to mitigate the damage caused by heading. PMID:26545274

  8. Abnormal head position in infantile nystagmus syndrome.

    PubMed

    Noval, Susana; González-Manrique, Mar; Rodríguez-Del Valle, José María; Rodríguez-Sánchez, José María

    2011-01-01

    Infantile nystagmus is an involuntary, bilateral, conjugate, and rhythmic oscillation of the eyes which is present at birth or develops within the first 6 months of life. It may be pendular or jerk-like and, its intensity usually increases in lateral gaze, decreasing with convergence. Up to 64% of all patients with nystagmus also present strabismus, and even more patients have an abnormal head position. The abnormal head positions are more often horizontal, but they may also be vertical or take the form of a tilt, even though the nystagmus itself is horizontal. The aim of this article is to review available information about the origin and treatment of the abnormal head position associated to nystagmus, and to describe our treatment strategies. PMID:24533187

  9. Car Accident Reconstruction and Head Injury Correlation

    NASA Astrophysics Data System (ADS)

    Chawla, A.; Grover, V.; Mukherjee, S.; Hassan, A. M.

    2013-04-01

    Estimation of brain damage remains an elusive issue and controlled tests leading to brain damage cannot be carried out on volunteers. This study reconstructs real-world car accidents to estimate the kinematics of the head impact. This data is to be used to estimate the head injury measures through computer simulations and then correlate reported skull as well as brain damage to impact measures; whence validating the head FE model (Willinger, IJCrash 8:605-617, 2003). In this study, two crash cases were reconstructed. Injury correlation was successful in one of these cases in that the injuries to the brain of one of the car drivers could be correlated in terms of type, location and severity when compared with the tolerance limits of relevant injury parameters (Willinger, IJCrash 8:605-617, 2003).

  10. Head wave correlations in ambient noise.

    PubMed

    Gebbie, John; Siderius, Martin

    2016-07-01

    Ambient ocean noise is processed with a vertical line array to reveal coherent time-separated arrivals suggesting the presence of head wave multipath propagation. Head waves, which are critically propagating water waves created by seabed waves traveling parallel to the water-sediment interface, can propagate faster than water-only waves. Such eigenrays are much weaker than water-only eigenrays, and are often completely overshadowed by them. Surface-generated noise is different whereby it amplifies the coherence between head waves and critically propagating water-only waves, which is measured by cross-correlating critically steered beams. This phenomenon is demonstrated both experimentally and with a full wave simulation. PMID:27475213

  11. Computerized system for translating a torch head

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

  12. Practical design of magnetic heading sensors

    NASA Technical Reports Server (NTRS)

    Garner, H. D.

    1986-01-01

    Although fluxgate magnetometers have been in use for many years, and a number of theoretical studies of these sensors are available, very little information has been published on the engineering choices relating to the detailed design of magnetometers intended for navigational applications in aircraft and other vehicles. This paper addresses some of the problems encountered in the design of the sensing head, the choice of operating mode, and the design of the supporting electronics for a simple low-cost magnetometer system which will produce a digital readout of the magnetic heading of the vehicle in which it is mounted. A major goal of this study has been to develop a design which minimizes circuit complexity, is easy to fabricate and calibrate, and utilizes a minimum of specialized components. Such a magnetometer system is intended either as a stand-alone indicating instrument or as a source of magnetic heading information for a more sophisticated navigational system.

  13. Head assembly for multiposition borehole extensometer

    SciTech Connect

    Frank, D.N.

    1983-05-10

    A head assembly for a borehole extensometer and an improved extensometer for measuring subsurface subsidence. A plurality of inflatable anchors provide discrete measurement points. A metering rod is fixed to each of the anchors which are displaced when subsidence occurs, thereby translating the attached rod. The head assembly includes a sprocket wheel rotatably mounted on a standpipe and engaged by a chain which is connected at one end to the metering rod and at the other end to a counterweight. A second sprocket wheel connected to the standpipe also engages the chain and drives a connected potentiometer. The head assembly converts the linear displacement of the metering rod to the rotary motion of the second sprocket wheel, which is measured by the potentiometer, producing a continuous electrical output.

  14. Head assembly for multiposition borehole extensometer

    SciTech Connect

    Frank, D.N.

    1981-06-09

    A head assembly for a borehole extensometer and an improved extensometer for measuring subsurface subsidence. A plurality of inflatable anchors provide discrete measurement points. A metering rod is fixed to each of the anchors which are displaced when subsidence occurs, thereby translating the attached rod. The head assembly includes a sprocket wheel rotatably mounted on a standpipe and engaged by a chain which is connected at one end to the metering rod and at the other end to a counterweight. A second sprocket wheel connected to the standpipe also engages the chain and drives a connected potentiometer. The head assembly converts the linear displacement of the metering rod to the rotary motion of the second sprocket wheel, which is measured by the potentiometer, producing a continuous electrical output.

  15. Radiotherapy for Head and Neck Cancer

    PubMed Central

    Yeh, Shyh-An

    2010-01-01

    Treatment for patients with head and neck cancer requires a multidisciplinary approach. Radiotherapy is employed as a primary treatment or as an adjuvant to surgery. Each specific subsite dictates the appropriate radiotherapy techniques, fields, dose, and fractionation scheme. Quality of life is also an important issue in the management of head and neck cancer. The radiation-related complications have a tremendous impact on the quality of life. Modern radiotherapy techniques, such as intensity-modulated radiotherapy and image-guided radiotherapy, can offer precise radiation delivery and reduce the dose to the surrounding normal tissues without compromise of target coverage. In the future, efforts should be made in the exploration of novel strategies to improve treatment outcome in patients with head and neck cancer. PMID:22550433

  16. Head assembly for multiposition borehole extensometer

    DOEpatents

    Frank, Donald N.

    1983-01-01

    A head assembly for a borehole extensometer and an improved extensometer for measuring subsurface subsidence. A plurality of inflatable anchors provide discrete measurement points. A metering rod is fixed to each of the anchors which are displaced when subsidence occurs, thereby translating the attached rod. The head assembly includes a sprocket wheel rotatably mounted on a standpipe and engaged by a chain which is connected at one end to the metering rod and at the other end to a counterweight. A second sprocket wheel connected to the standpipe also engages the chain and drives a connected potentiometer. The head assembly converts the linear displacement of the metering rod to the rotary motion of the second sprocket wheel, which is measured by the potentiometer, producing a continuous electrical output.

  17. Head stereotypies in STXBP1 encephalopathy.

    PubMed

    Kim, Young Ok; Korff, Christian M; Villaluz, Mel Michel G; Suls, Arvid; Weckhuysen, Sarah; De Jonghe, Peter; Scheffer, Ingrid E

    2013-08-01

    STXBP1 encephalopathy is associated with a range of movement disorders. We observed head stereotypies in three patients. These comprised a slow (<1Hz), high-amplitude, horizontal, 'figure-of-eight' pattern, beginning at age 4-6 years and resulting in neck muscle hypertrophy, in two males; a faster (2-3Hz), side-to-side, 'no' movement, starting at the age of 9 years 6 months was observed in one female. Upper limb and truncal stereotypies and vocalization occurred intermittently with the head movements. The stereotypies increased with excitement but settled with concentration and sleep. Head and upper limb stereotypies are valuable clinical clues to the diagnosis of STXBP1 encephalopathy in patients with profound impairments. PMID:23763664

  18. Variability of blowfly head optomotor responses.

    PubMed

    Rosner, R; Egelhaaf, M; Grewe, J; Warzecha, A K

    2009-04-01

    Behavioural responses of an animal are variable even when the animal experiences the same sensory input several times. This variability can arise from stochastic processes inherent to the nervous system. Also, the internal state of an animal may influence a particular behavioural response. In the present study, we analyse the variability of visually induced head pitch responses of tethered blowflies by high-speed cinematography. We found these optomotor responses to be highly variable in amplitude. Most of the variability can be attributed to two different internal states of the flies with high and low optomotor gain, respectively. Even within a given activity state, there is some variability of head optomotor responses. The amount of this variability differs for the two optomotor gain states. Moreover, these two activity states can be distinguished on a fine timescale and without visual stimulation, on the basis of the occurrence of peculiar head jitter movements. Head jitter goes along with high gain optomotor responses and haltere oscillations. Halteres are evolutionary transformed hindwings that oscillate when blowflies walk or fly. Their main function is to serve as equilibrium organs by detecting Coriolis forces and to mediate gaze stabilisation. However, their basic oscillating activity was also suggested to provide a gain-modulating signal. Our experiments demonstrate that halteres are not necessary for high gain head pitch to occur. Nevertheless, we find the halteres to be responsible for one component of head jitter movements. This component may be the inevitable consequence of their function as equilibrium and gaze-stabilising organs. PMID:19329750

  19. Management of femoral head osteonecrosis: Current concepts

    PubMed Central

    Tripathy, Sujit Kumar; Goyal, Tarun; Sen, Ramesh Kumar

    2015-01-01

    Osteonecrosis of femoral head (ONFH) is a disabling condition of young individuals with ill-defined etiology and pathogenesis. Remains untreated, about 70-80% of the patients progress to secondary hip arthritis. Both operative and nonoperative treatments have been described with variable success rate. Early diagnosis and treatment is the key for success in preserving the hip joint. Once femoral head collapses (>2 mm) or if there is secondary degeneration, hip conservation procedures become ineffective and arthroplasty remains the only better option. We reviewed 157 studies that evaluate different treatment modalities of ONFH and then a final consensus on treatment was made. PMID:25593355

  20. Imaging of head and neck emergencies.

    PubMed

    Brucker, Justin L; Gentry, Lindell R

    2015-01-01

    The anatomy of the head and neck contains very few structures that could be considered expendable and, consequently, is exceptionally intolerant to infection, inflammation, and injury. Acute pathologic processes in this body region, therefore, tend to result in significant suffering, functional impairment, or life endangerment if the diagnosis is missed or treatment is delayed. Many emergent processes within the cervical region also need to be considered for their possible impact on structures within the head and chest, into which there are many routes for potential communication. PMID:25476182