Effect of temperature on endplate potential rundown and recovery in rat diaphragm.
Moyer, M; van Lunteren, E
2001-05-01
The amplitude of neuromuscular junction end-plate potentials (EPPs) decreases quickly within a train but recovers nearly completely from train to train during intermittent stimulation. Rundown has been shown to be dependent not only on the rate of transmitter release but also on the rate of replenishment of the depleted neurotransmitter at the site of release. Two groups of processes have been proposed for synaptic vesicle recycling, both of which involve multiple energy-requiring steps and enzymatic reactions and which therefore would be expected to be very temperature-sensitive. The present study tested the hypothesis that low temperature therefore increases the rate of EPP amplitude rundown. Studies were performed in vitro on rat diaphragm and used micro-conotoxin to allow normal-sized EPPs to be recorded from intact fibers. EPP amplitude rundown during intermittent stimulation at 20 and 50 Hz (duty cycle 333 ms) was greater at 20 degrees C than it was at 37 degrees C. Initially, temperature affected only intra-train rundown but, over longer periods of stimulation, both intra- and inter-train rundown were significantly accelerated by cold temperature. Cumulative EPP amplitudes were calculated by successively adding the amplitudes of each EPP during the stimulation period to provide an estimate of total neurotransmitter release in the neuromuscular junction. The cumulative EPP amplitude was significantly lower at 20 degrees C than it was at 37 degrees C during both 20 and 50 Hz stimulation. These data indicate that the mechanism involved in EPP amplitude rundown and recovery is temperature-sensitive, with a greater decrement in EPP amplitude at cold than at warm temperatures.
Muscle paralyzing effect of the juice from the trunk of the banana tree.
Singh, Y N; Dryden, W F
1985-01-01
The effect of an extract from the trunk of the banana tree (Musa sapientum) was investigated in isolated skeletal muscle preparations from the chick, mouse and frog using twitch tension and intracellular recording techniques. The extract produced, in the same concentration range and after an initial period of twitch augmentation, paralysis of skeletal muscle in both directly and indirectly stimulated preparations. It also had a dose-dependent stimulant effect on the muscle causing a contracture. The neuromuscular blockade was reversed by calcium, but only when added before complete paralysis of the muscle. On the other hand, neostigmine usually hastened the blockade and aggravated the contracture. The frequency of the miniature endplate potential in the mouse phrenic nerve-diaphragm preparation greatly increased initially, declining to an elevated plateau. Effects on quantal content of endplate potentials (e.p.p.s) were studied in the transected mouse phrenic nerve-hemidiaphragm using trains of e.p.p.s. In the presence of the extract, only a few e.p.p. trains could normally be evoked, probably due to nerve terminal block. When quantal content could be measured at low concentrations of the extract, an increase was usually obtained. Muscle action potentials in the frog sartorius muscle were decreased in amplitude until no further potentials could be generated. The results suggest that the nature of the block produced by the extract resembles that of a potent local anaesthetic with an initial atypical labilizing effect on cell calcium rather than a conventional curariform block.
Gillingwater, Thomas H; Thomson, Derek; Mack, Till G A; Soffin, Ellen M; Mattison, Richard J; Coleman, Michael P; Ribchester, Richard R
2002-01-01
Axons in WldS mutant mice are protected from Wallerian degeneration by overexpression of a chimeric Ube4b/Nmnat (Wld) gene. Expression of Wld protein was independent of age in these mice. However we identified two distinct neuromuscular synaptic responses to axotomy. In young adult Wlds mice, axotomy induced progressive, asynchronous synapse withdrawal from motor endplates, strongly resembling neonatal synapse elimination. Thus, five days after axotomy, 50–90 % of endplates were still partially or fully occupied and expressed endplate potentials (EPPs). By 10 days, fewer than 20 % of endplates still showed evidence of synaptic activity. Recordings from partially occupied junctions indicated a progressive decrease in quantal content in inverse proportion to endplate occupancy. In Wlds mice aged > 7 months, axons were still protected from axotomy but synapses degenerated rapidly, in wild-type fashion: within three days less than 5 % of endplates contained vestiges of nerve terminals. The axotomy-induced synaptic withdrawal phenotype decayed with a time constant of ∼30 days. Regenerated synapses in mature Wlds mice recapitulated the juvenile phenotype. Within 4–6 days of axotomy 30–50 % of regenerated nerve terminals still occupied motor endplates. Age-dependent synapse withdrawal was also seen in transgenic mice expressing the Wld gene. Co-expression of Wld protein and cyan fluorescent protein (CFP) in axons and neuromuscular synapses did not interfere with the protection from axotomy conferred by the Wld gene. Thus, Wld expression unmasks age-dependent, compartmentally organised programmes of synapse withdrawal and degeneration. PMID:12231635
Meunier, Frédéric A; Mercado, José A; Molgó, Jordi; Tosteson, Thomas R; Escalona de Motta, Gladys
1997-01-01
The actions of a chromatographically identified extract of the marine dinoflagellate Ostreopsis lenticularis, named ostreotoxin-3 (OTX-3), were studied on frog isolated neuromuscular preparations. OTX-3 (1–10 μg ml−1) applied to cutaneous pectoris nerve-muscle preparations depolarized skeletal muscle fibres and caused spontaneous contractions. The depolarization was neither reversed by prolonged washing nor by (+)-tubocurarine. OTX-3 decreased the amplitude of miniature end plate potentials (m.e.p.ps) but did not affect their frequency. Extracellular recording of compound action potentials revealed that OTX-3 affected neither excitability nor conduction along intramuscular nerve branches. End-plate potentials (e.p.ps) elicited by nerve stimulation were reduced in amplitude by OTX-3 and even showed reversed polarity in junctions deeply depolarized by the toxin. Membrane depolarization induced by OTX-3 was decreased about 70% in muscles pretreated for 30 min with 10 μM tetrodotoxin. In contrast, muscles pretreated with 5 μM μ-conotoxin GIIIA were completely insensitive to OTX-3-induced depolarization. OTX-3 did not affect e.p.p. amplitude and the quantal content of e.p.ps in junctions in which muscle depolarization was abolished by μ-conotoxin GIIIA. OTX-3 is a novel type of sodium-channel activating toxin that discriminates between nerve and skeletal muscle membranes. PMID:9249261
Blocking p75 (NTR) receptors alters polyinnervationz of neuromuscular synapses during development.
Garcia, Neus; Tomàs, Marta; Santafe, Manel M; Lanuza, Maria A; Besalduch, Nuria; Tomàs, Josep
2011-09-01
High-resolution immunohistochemistry shows that the receptor protein p75(NTR) is present in the nerve terminal, muscle cell, and glial Schwann cell at the neuromuscular junction (NMJ) of postnatal rats (P4-P6) during the synapse elimination period. Blocking the receptor with the antibody anti-p75-192-IgG (1-5 μg/ml, 1 hr) results in reduced endplate potentials (EPPs) in mono- and polyinnervated synapses ex vivo, but the mean number of functional inputs per NMJ does not change for as long as 3 hr. Incubation with exogenous brain-derived neurotrophic factor (BDNF) for 1 hr (50 nM) resulted in a significant increase in the size of the EPPs in all nerve terminals, and preincubation with anti-p75-192-IgG prevented this potentiation. Long exposure (24 hr) in vivo of the NMJs to the antibody anti-p75-192-IgG (1-2 μg/ml) results in a delay of postnatal synapse elimination and even some regrowth of previously withdrawn axons, but also in some acceleration of the morphologic maturation of the postsynaptic nicotinic acetylcholine receptor (nAChR) clusters. The results indicate that p75(NTR) is involved in both ACh release and axonal retraction during postnatal axonal competition and synapse elimination. Copyright © 2011 Wiley-Liss, Inc.
Melaré, Rodolfo; Floriano, Rafael Stuani; Gracia, Marta; Rodrigues-Simioni, Léa; Cruz-Höfling, Maria Alice da; Rocha, Thalita
2016-11-01
Bites by Bothrops snakes normally induce local pain, haemorrhage, oedema and myonecrosis. Mammalian isolated nerve-muscle preparations exposed to Bothrops venoms and their phospholipase A 2 toxins (PLA 2 ) can exhibit a neurotoxic pattern as increase in frequency of miniature end-plate potentials (MEPPs) as well as in amplitude of end-plate potentials (EPPs); neuromuscular facilitation followed by complete and irreversible blockade without morphological evidence for muscle damage. In this work, we analysed the ultrastructural damage induced by Bothrops jararacussu and Bothrops bilineatus venoms and their PLA 2 toxins (BthTX-I and Bbil-TX) in mouse isolated nerve-phrenic diaphragm preparations (PND). Under transmission electron microscopy (TEM), PND preparations previously exposed to B. jararacussu and B. bilineatus venoms and BthTX-I and Bbil-TX toxins showed hypercontracted and loosed myofilaments; unorganized sarcomeres; clusters of edematous sarcoplasmic reticulum and mitochondria; abnormal chromatin distribution or apoptotic-like nuclei. The principal affected organelles, mitochondria and sarcoplasmic reticulum, were those related to calcium buffering and, resulting in sarcomeres and myofilaments hypercontraction. Schwann cells were also damaged showing edematous axons and mitochondria as well as myelin sheath alteration. These ultrastructural changes caused by both of Bothrops venoms and toxins indicate that the neuromuscular blockade induced by them in vitro can also be associated with nerve and muscle degeneration. © 2016 Wiley Periodicals, Inc.
NASA Technical Reports Server (NTRS)
Chen, B. M.; Grinnell, A. D.
1997-01-01
Neurotransmitter release from frog motor nerve terminals is strongly modulated by change in muscle length. Over the physiological range, there is an approximately 10% increase in spontaneous and evoked release per 1% muscle stretch. Because many muscle fibers do not receive suprathreshold synaptic inputs at rest length, this stretch-induced enhancement of release constitutes a strong peripheral amplifier of the spinal stretch reflex. The stretch modulation of release is inhibited by peptides that block integrin binding of natural ligands. The modulation varies linearly with length, with a delay of no more than approximately 1-2 msec and is maintained constant at the new length. Moreover, the stretch modulation persists in a zero Ca2+ Ringer and, hence, is not dependent on Ca2+ influx through stretch activated channels. Eliminating transmembrane Ca2+ gradients and buffering intraterminal Ca2+ to approximately normal resting levels does not eliminate the modulation, suggesting that it is not the result of release of Ca2+ from internal stores. Finally, changes in temperature have no detectable effect on the kinetics of stretch-induced changes in endplate potential (EPP) amplitude or miniature EPP (mEPP) frequency. We conclude, therefore, that stretch does not act via second messenger pathways or a chemical modification of molecules involved in the release pathway. Instead, there is direct mechanical modulation of release. We postulate that tension on integrins in the presynaptic membrane is transduced mechanically into changes in the position or conformation of one or more molecules involved in neurotransmitter release, altering sensitivity to Ca2+ or the equilibrium for a critical reaction leading to vesicle fusion.
Datyner, M. E.; Gage, P. W.
1973-01-01
1. Crude venom (TSV) from the Australian tiger snake (Notechis scutatus scutatus) has both presynaptic and postsynaptic effects at the neuromuscular junctions of toads. 2. TSV (50 μg/ml) rapidly blocked indirectly elicited muscle twitches without affecting the compound action potential in the sciatic nerve or twitches elicited by direct stimulation. 3. Low concentrations of the venom (1-10 μg/ml) reduced the amplitude of miniature endplate potentials (m.e.p.ps) and inhibited the depolarization of muscle fibres normally caused by carbachol. It was concluded that a fraction of the venom binds to acetylcholine receptors. 4. The frequency of m.e.p.ps was at first increased by TSV at a concentration of 1 μg/ml. Occasional, high frequency `bursts' of m.e.p.ps were recorded in some preparations. The mean frequency of m.e.p.ps appeared to fall after several hours in the venom. 5. The quantal content of endplate potentials (e.p.ps) was reduced by the venom. With low concentrations (1 μg/ml), an initial increase in quantal content was often seen. When the quantal content was markedly depressed there was no parallel reduction in the amplitude of nerve terminal spikes recorded extracellularly, though a later fall in size and slowing of time course was often seen. 6. There was evidence that TSV eventually changed the normal Poisson characteristics of the spontaneous release of quanta and this may be correlated with electronmicroscopic changes in nerve terminals. 7. Tiger snake antivenene counteracted the postsynaptic, but not the presynaptic effects of TSV when they had developed. PMID:4367126
Malomouzh, Artem I; Petrov, Konstantin A; Nurullin, Leniz F; Nikolsky, Evgeny E
2015-12-01
Gamma-aminobutyric acid (GABA) is an amino acid which acts as a neurotransmitter in the central nervous system. Here, we studied the effects of GABA on non-quantal, spontaneous, and evoked quantal acetylcholine (ACh) release from motor nerve endings. We found that while the application of 10 μM of GABA had no effect on spontaneous quantal ACh release, as detected by the frequency of miniature endplate potentials, GABA reduced the non-quantal ACh release by 57%, as determined by the H-effect value. Finally, the evoked quantal ACh release, estimated by calculating the quantal content of full-sized endplate potentials (EPPs), was reduced by 34%. GABA's inhibitory effect remained unchanged after pre-incubation with picrotoxin, an ionotropic GABAA receptor blocker, but was attenuated following application of the GABAB receptor blocker CGP 55845, which itself had no effect on ACh release. An inhibitor of phospholipase C, U73122, completely prevented the GABA-induced decrease in ACh release. Immunofluorescence demonstrated the presence of both subunits of the GABAB receptor (GABAB R1 and GABAB R2) in the neuromuscular junction. These findings suggest that metabotropic GABAB receptors are expressed in the mammalian neuromuscular synapse and their activation results in a phospholipase C-mediated reduction in the intensity of non-quantal and evoked quantal ACh release. We investigated the effect of gamma-aminobutyric acid (GABA) on neuromuscular transmission. GABA reduced the non-quantal and evoked quantal release of acetylcholine. These effects are mediated by GABAB receptors and are implemented via phospholipase C (PLC) activation. Our findings suggest that in the mammalian neuromuscular synapse, metabotropic GABAB receptors are expressed and their activation results in a reduction in the intensity of acetylcholine release. © 2015 International Society for Neurochemistry.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Grandič, Marjana; Aráoz, Romulo; Molgó, Jordi
APS12-2, a non-competitive acetylcholinesterase inhibitor, is one of the synthetic analogs of polymeric alkylpyridinium salts (poly-APS) isolated from the marine sponge Reniera sarai. In the present work the effects of APS12-2 were studied on isolated mouse phrenic nerve–hemidiaphragm muscle preparations, using twitch tension measurements and electrophysiological recordings. APS12-2 in a concentration-dependent manner blocked nerve-evoked isometric muscle contraction (IC{sub 50} = 0.74 μM), without affecting directly-elicited twitch tension up to 2.72 μM. The compound (0.007–3.40 μM) decreased the amplitude of miniature endplate potentials until a complete block by concentrations higher than 0.68 μM, without affecting their frequency. Full size endplate potentials,more » recorded after blocking voltage-gated muscle sodium channels, were inhibited by APS12-2 in a concentration-dependent manner (IC{sub 50} = 0.36 μM) without significant change in the resting membrane potential of the muscle fibers up to 3.40 μM. The compound also blocked acetylcholine-evoked inward currents in Xenopus oocytes in which Torpedo (α1{sub 2}β1γδ) muscle-type nicotinic acetylcholine receptors (nAChRs) have been incorporated (IC{sub 50} = 0.0005 μM), indicating a higher affinity of the compound for Torpedo (α1{sub 2}β1γδ) than for the mouse (α1{sub 2}β1γε) nAChR. Our data show for the first time that APS12-2 blocks neuromuscular transmission by a non-depolarizing mechanism through an action on postsynaptic nAChRs of the skeletal neuromuscular junction. -- Highlights: ► APS12-2 produces concentration-dependent inhibition of nerve-evoked muscle contraction in vitro. ► APS12-2 blocks MEPPs and EPPs at the neuromuscular junction. APS12-2 blocks ACh-activated current in Xenopus oocytes incorporated with Torpedo nAChRs.« less
Lambooij, Mattijs S; Koster, Ferry
2016-05-20
Escalation of commitment is the tendency that (innovation) projects continue, even if it is clear that they will not be successful and/or become extremely costly. Escalation prevention potential (EPP), the capability of an organization to stop or steer implementation processes that do not meet their expectations, may prevent an organization of losing time and money on unsuccessful projects. EPP consists of a set of checks and balances incorporated in managerial practices that safeguard management against irrational (but very human) decisions and may limit the escalation of implementation projects. We study whether successful implementation of electronic medical records (EMRs) relates to EPP and investigate the organizational factors accounting for this relationship. Structural equation modelling (SEM), using questionnaire data of 427 doctors and 631 nurses who had experience with implementation and use of EMRs in hospitals, was applied to study whether formal governance and organizational culture mediate the relationship between EPP and the perceived added value of EMRs. Doctors and nurses in hospitals with more EPP report more successful implementation of EMR (in terms of perceived added value of the EMR). Formal governance mediates the relation between EPP and implementation success. We found no evidence that open or innovative culture explains the relationship between EPP and implementation success. There is a positive relationship between the level of EPP and perceived added value of EMRs. This relationship is explained by formal governance mechanisms of organizations. This means that management has a set of tangible tools to positively affect the success of innovation processes. However, it also means that management needs to be able to critically reflect on its (previous) actions and decisions and is willing to change plans if elements of EPP signal that the implementation process is hampered.
Reiter, Matthew E.; Andersen, David E.; Raedeke, Andrew H.; Humburg, Dale D.
2017-01-01
Inter- and intra-specific interactions are potentially important factors influencing the distribution of populations. Aerial survey data, collected during range-wide breeding population surveys for Eastern Prairie Population (EPP) Canada Geese (Branta canadensis interior), 1987–2008, were evaluated to assess factors influencing their nesting distribution. Specifically, associations between nesting Lesser Snow Geese (Chen caerulescens caerulescens) and EPP Canada Geese were quantified; and changes in the spatial distribution of EPP Canada Geese were identified. Mixed-effects Poisson regression models of EPP Canada Goose nest counts were evaluated within a cross-validation framework. The total count of EPP Canada Goose nests varied moderately among years between 1987 and 2008 with no long-term trend; however, the total count of nesting Lesser Snow Geese generally increased. Three models containing factors related to previous EPP Canada Goose nest density (representing recruitment), distance to Hudson Bay (representing brood-habitat), nesting habitat type, and Lesser Snow Goose nest density (inter-specific associations) were the most accurate, improving prediction accuracy by 45% when compared to intercept-only models. EPP Canada Goose nest density varied by habitat type, was negatively associated with distance to coastal brood-rearing areas, and suggested density-dependent intra-specific effects on recruitment. However, a non-linear relationship between Lesser Snow and EPP Canada Goose nest density suggests that as nesting Lesser Snow Geese increase, EPP Canada Geese locally decline and subsequently the spatial distribution of EPP Canada Geese on western Hudson Bay has changed.
The effect of papaine on the time course of the end-plate current.
Humar, M; Kordas, M; Melik, Z
1980-07-01
Papaine is known to detach cholinesterases from the synaptic cleft. It could be expected that this would result in an increase of the amplitude and half-time of the end-plate current. Thus, the effect of papaine on the end-plate current. Thus, the effect of papaine on the end-plate current should be similar to the effect of anticholinesterase methanesulfonylfluoride. The end-plate current was recorded in frog skeletal muscle at various levels of membrane potential, before and after papaine was added to the bath. The effect of papaine was an increase of the half-time of the end-plate current, similarly as after treatment of the muscle by methanesulfonylfluoride. It seems that both papaine and methanesulfonylfluoride have a similar mechanism of action. In either experimental condition hydrolysis of transmitter is decreased or abolished, which results in an increase of the half-time of the end-plate current.
Cao, Yong; Liao, Shenghui; Zeng, Hao; Ni, Shuangfei; Tintani, Francis; Hao, Yongqiang; Wang, Lei; Wu, Tianding; Lu, Hongbin; Duan, Chunyue; Hu, Jianzhong
2017-01-01
A better understanding of functional changes in the intervertebral disc (IVD) and interaction with endplate is essential to elucidate the pathogenesis of IVD degeneration disease (IDDD). To date, the simultaneous depiction of 3D micro-architectural changes of endplate with aging and interaction with IVD remains a technical challenge. We aim to characterize the 3D morphology changes of endplate and IVD during aging using PPCST. The lumbar vertebral level 4/5 IVDs harvested from 15-day-, 4- and 24-month-old mice were initially evaluated by PPCST with histological sections subsequently analyzed to confirm the imaging efficiency. Quantitative assessments of age-related trends after aging, including mean diameter, volume fraction and connectivity of the canals, and endplate porosity and thickness, reached a peak at 4 months and significantly decreased at 24 months. The IVD volume consistently exhibited same trend of variation with the endplate after aging. In this study, PPCST simultaneously provided comprehensive details of 3D morphological changes of the IVD and canal network in the endplate and the interaction after aging. The results suggest that PPCST has the potential to provide a new platform for attaining a deeper insight into the pathogenesis of IDDD, providing potential therapeutic targets. PMID:28266560
Effects of dithiothreitol on end-plate currents.
Terrar, D A
1978-01-01
1. End-plate currents have been studied in frog cutaneus pectoris nerve-muscle preparations mounted in continuously flowing solution, using the voltage clamp technique. 2. Exposure of the muscle to 1 mM-dithiothreitol reduced the amplitude of end-plate currents by a factor of 2.7 (mean; range 1.6-3.4; twelve fibres). 3. 1 mM-dithiothreitol also caused a 2.7-fold (2.3-3.1) increase in the rate of decay, and a 1.4-fold (1.3-1.6) decrease in the time to peak of end-plate currents. During the onset of action of dithiothreitol, there was little or no indication of departure of end-plate current decay from a simple exponential. 4. Dithiothreitol actions on amplitude and decay of end-plate currents developed with similar time courses and both effects were slower in onset at pH 7.2 than at pH 8.5. 5. The actions of dithiothreitol were reversed by exposure of the muscle to 1 mM-5,5'-dithio-bis-(2-nitrobenzoic acid). 6. Following dithiothreitol treatment, the rates of decay of end-plate currents continued to depend on membrane potential; there was little or no change in the slope of the relation between in (rate of decay) and membrane potential, consistent with little or no change in the dipole moment of a gating molecule for ion channels. 7. Dithiothreitol changed the relation between peak end-plate current and membrane potential, so that peak conductance increased at more negative membrane potentials; this finding could be accounted for in terms of the closure of ion-channel gates becoming faster though remaining voltage-sensitive after exposure to dithiothreitol. 8. It is concluded that dithiothreitol causes changes in the kinetics of gating of ion channels associated with receptors and that these changes accompany changes in the binding of ACh to receptors. PMID:25960
Exacerbation of erythropoietic protoporphyria by hyperthyroidism.
Minder, Elisabeth I; Haldemann, Andreas R; Schneider-Yin, Xiaoye
2010-12-01
Erythropoietic protoporphyria (EPP) is a hereditary disorder caused by deficiency of ferrochelatase, the last enzyme in the heme biosynthetic pathway. The majority of EPP patients present with a clinical symptom of painful phototoxicity. Liver damage, the most serious complication of EPP, occurs in <5% of the patients. This report describes a case of an EPP patient who complained of worsening cutaneous symptoms, nervousness, and insomnia. Laboratory tests showed highly increased protoporphyrin concentration in erythrocytes and elevated serum transaminases that are indicative of EPP-related liver damage. The subsequent finding of decreased serum thyroid-stimulating hormone (TSH) and increased free triiodothyronine (FT3) and free thyroxine (FT4) concentrations, as well antibodies against both thyroid peroxidase (TPO) and TSH receptors, led to the diagnosis of Graves' disease. The patient received 500 MBq of radioiodine (I(131)). Three months after the radioactive iodine therapy, the thyroid volume was reduced to 30% of pretherapeutic volume. Although the patient was slightly hypothyroidic, his liver enzymes returned to normal, his erythrocytic protoporphyrin concentration dropped fivefold, and his skin symptoms improved dramatically. The coexistence of Graves' disease and EPP is a statistically rare event as, besides our patient, there was one additional case reported in the literature. Although the exact mechanism whereby Graves' disease interacts with EPP is yet to be explored, we recommend testing thyroid function in EPP patients with liver complication to exclude hyperthyroidism as a potential cause.
Simulation of miniature endplate potentials in neuromuscular junctions by using a cellular automaton
NASA Astrophysics Data System (ADS)
Avella, Oscar Javier; Muñoz, José Daniel; Fayad, Ramón
2008-01-01
Miniature endplate potentials are recorded in the neuromuscular junction when the acetylcholine contents of one or a few synaptic vesicles are spontaneously released into the synaptic cleft. Since their discovery by Fatt and Katz in 1952, they have been among the paradigms in neuroscience. Those potentials are usually simulated by means of numerical approaches, such as Brownian dynamics, finite differences and finite element methods. Hereby we propose that diffusion cellular automata can be a useful alternative for investigating them. To illustrate this point, we simulate a miniature endplate potential by using experimental parameters. Our model reproduces the potential shape, amplitude and time course. Since our automaton is able to track the history and interactions of each single particle, it is very easy to introduce non-linear effects with little computational effort. This makes cellular automata excellent candidates for simulating biological reaction-diffusion processes, where no other external forces are involved.
Dual Electrolytic Plasma Processing for Steel Surface Cleaning and Passivation
NASA Astrophysics Data System (ADS)
Yang, L.; Zhang, P.; Shi, J.; Liang, J.; Tian, W. B.; Zhang, Y. M.; Sun, Z. M.
2017-10-01
To remove the rust on rebars and passivate the fresh surfaces, electrodes reversing electrolytic plasma processing (EPP) was proposed and conducted in a 10 wt.% Na2CO3 aqueous solution. The morphology and the composition of the surface were investigated by SEM and XPS. Experimental results show that the rust on the surface was removed effectively by cathode EPP, and a passive film containing Cr2O3 was achieved by the succeeding anode EPP treatment, by a simple operation of reversing the bias. The corrosion resistance was evaluated in a 3.5 wt.% NaCl aqueous solution using an electrochemical workstation. In comparison, the corrosion resistance was improved by the succeeding anode EPP treatment, which is evidenced by a positive shift of the open-circuit potential, an increase in the electrochemical impedance representing the inner layer by 76.8% and the decrease in the corrosion current density by 49.6%. This is an effective and environment-friendly technique to clean and passivate rebars and similar steel materials.
Besalduch, Núria; Santafé, Manel M; Garcia, Neus; Gonzalez, Carmen; Tomás, Marta; Tomás, Josep; Lanuza, Maria A
2011-04-01
We studied structural and functional features of the neuromuscular junction in adult mice (P30) genetically deficient in the protein kinase C (PKC) theta isoform. Confocal and electron microscopy shows that there are no differences in the general morphology of the endplates between PKC theta-deficient and wild-type (WT) mice. Specifically, there is no difference in the density of the synaptic vesicles. However, the myelin sheath is not as thick in the intramuscular nerve fibers of the PKC theta-deficient mice. We found a significant reduction in the size of evoked endplate potentials and in the frequency of spontaneous, asynchronous, miniature endplate potentials in the PKC theta-deficient neuromuscular preparations in comparison with the WT, but the mean amplitude of the spontaneous potentials is not different. These changes indicate that PKC theta has a presynaptic role in the function of adult neuromuscular synapses. Copyright © 2010 Wiley-Liss, Inc.
Epp: A C++ EGSnrc user code for x-ray imaging and scattering simulations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lippuner, Jonas; Elbakri, Idris A.; Cui Congwu
2011-03-15
Purpose: Easy particle propagation (Epp) is a user code for the EGSnrc code package based on the C++ class library egspp. A main feature of egspp (and Epp) is the ability to use analytical objects to construct simulation geometries. The authors developed Epp to facilitate the simulation of x-ray imaging geometries, especially in the case of scatter studies. While direct use of egspp requires knowledge of C++, Epp requires no programming experience. Methods: Epp's features include calculation of dose deposited in a voxelized phantom and photon propagation to a user-defined imaging plane. Projection images of primary, single Rayleigh scattered, singlemore » Compton scattered, and multiple scattered photons may be generated. Epp input files can be nested, allowing for the construction of complex simulation geometries from more basic components. To demonstrate the imaging features of Epp, the authors simulate 38 keV x rays from a point source propagating through a water cylinder 12 cm in diameter, using both analytical and voxelized representations of the cylinder. The simulation generates projection images of primary and scattered photons at a user-defined imaging plane. The authors also simulate dose scoring in the voxelized version of the phantom in both Epp and DOSXYZnrc and examine the accuracy of Epp using the Kawrakow-Fippel test. Results: The results of the imaging simulations with Epp using voxelized and analytical descriptions of the water cylinder agree within 1%. The results of the Kawrakow-Fippel test suggest good agreement between Epp and DOSXYZnrc. Conclusions: Epp provides the user with useful features, including the ability to build complex geometries from simpler ones and the ability to generate images of scattered and primary photons. There is no inherent computational time saving arising from Epp, except for those arising from egspp's ability to use analytical representations of simulation geometries. Epp agrees with DOSXYZnrc in dose calculation, since they are both based on the well-validated standard EGSnrc radiation transport physics model.« less
High Fidelity – No Evidence for Extra-Pair Paternity in Siberian Jays (Perisoreus infaustus)
Gienapp, Phillip; Merilä, Juha
2010-01-01
Extra-pair paternity (EPP) in birds is related to a number of ecological and social factors. For example, it has been found to be positively related with breeding density, negatively with the amount of paternal care and especially high rates have been observed in group-living species. Siberian jays (Perisoreous infaustus) breed at low densities and have extended parental care, which leads to the expectation of low rates of EPP. On the other hand, Siberian jays live in groups which can include also unrelated individuals, and provide opportunities for extra-pair matings. To assess the potential occurrence of EPP in Siberian jays, we analysed a large data pool (n = 1029 offspring) covering ca. 30 years of samples from a Finnish Siberian jay population. Paternities were assigned based on up to 21 polymorphic microsatellite markers with the additional information from field observations. We were unable to find any evidence for occurrence of EPP in this species. Our findings are in line with earlier studies and confirm the generally low rates of EPP in related Corvid species. These results suggest that ecological factors may be more important than social factors (group living) in determining costs and benefits of extra-pair paternity. PMID:20711255
Shape memory alloy-based moment connections with superior self-centering properties
NASA Astrophysics Data System (ADS)
Farmani, Mohammad Amin; Ghassemieh, Mehdi
2016-07-01
Superelastic shape memory alloys (SMAs) have the potential to create a spontaneous recentering mechanism on the connections of a structural system under seismic actions, which results in mitigation of the damage in the main structural members. In this article, innovative types of steel beam-to-column moment connections incorporating SMA bolts and plates are introduced and studied through a numerical approach. First, SMA bolted end-plate connection model is produced and analyzed by means of the finite element method to validate the numerical analysis against the prior experimental results. Then, the performance of eleven different end-plate moment connection models subjected to cyclic loading is investigated. By selecting the lower values for the moment capacity based on bolts strength in comparison to the flexural resistance of the beam, the plastic hinge is transferred from the beam section to the beam-column interface. Hence, employing superelastic materials at the connection interface could be potentially effective in providing the desired self-centering effect in the connection. To this end, the impact of utilizing superelastic SMA bolts and end-plates instead of using the conventional structural steel on the overall cyclic response of the connections is evaluated in this study. Results show that extended end-plate connections equipped with SMA bolts and end-plates, if properly proportioned and detailed, not only exhibit a clear reduction in the residual drifts after a seismic event, but also can meet the ductility requirements with good energy dissipation and sufficient stiffness.
Bainbridge, A; Tachtsidis, I; Faulkner, S D; Price, D; Zhu, T; Baer, E; Broad, K D; Thomas, D L; Cady, E B; Robertson, N J; Golay, X
2014-11-15
Multimodal measurements combining broadband near-infrared spectroscopy (NIRS) and phosphorus magnetic resonance spectroscopy ((31)P MRS) assessed associations between changes in the oxidation state of cerebral mitochondrial cytochrome-c-oxidase (Δ[oxCCO]) and (31)P metabolite peak-area ratios during and after transient cerebral hypoxia-ischemia (HI) in the newborn piglet. Twenty-four piglets (aged<24 h) underwent transient HI (inspired oxygen fraction 9% and bilateral carotid artery occlusion for ~20 min). Whole-brain (31)P MRS and NIRS data were acquired every minute. Inorganic phosphate (Pi)/epp, phosphocreatine (PCr)/epp, and total nucleotide triphosphate (NTP)/epp were measured by (31)P MRS and were plotted against Δ[oxCCO] during HI and recovery (epp=exchangeable phosphate pool=Pi+PCr+2γ-NTP+β-NTP). During HI Δ[oxCCO], PCr/epp and NTP/epp declined and Pi/epp increased. Significant correlations were seen between (31)P ratios and Δ[oxCCO]; during HI a threshold point was identified where the relationship between Δ[oxCCO] and both NTP/epp and Pi/epp changed significantly. Outcome at 48 h related to recovery of Δ[oxCCO] and (31)P ratios 1h post-HI (survived: 1-h NTP/epp 0.22 ± 0.02, Δ[oxCCO] -0.29 ± 0.50 μM; died: 1-h NTP/epp 0.10 ± 0.04, Δ[oxCCO] -2.41 ± 1.48 μM). Both lowered Δ[oxCCO] and NTP/epp 1h post-HI indicated mitochondrial impairment. Animals dying before 48 h had slower recovery of both Δ[oxCCO] and (31)P ratios by 1 h after HI. © 2013.
Polarization entanglement purification for concatenated Greenberger-Horne-Zeilinger state
NASA Astrophysics Data System (ADS)
Zhou, Lan; Sheng, Yu-Bo
2017-10-01
Entanglement purification plays a fundamental role in long-distance quantum communication. In the paper, we put forward the first polarization entanglement purification protocol (EPP) for one type of nonlocal logic-qubit entanglement, i.e., concatenated Greenberger-Horne-Zeilinger (C-GHZ) state, resorting to the photon-atom interaction in low-quality (Q) cavity. In contrast to existing EPPs, this protocol can purify the bit-flip error and phase-flip error in both physic and logic level. Instead of measuring the photons directly, this protocol only requires to measure the atom states to judge whether the protocol is successful. In this way, the purified logic entangled states can be preserved for further application. Moreover, it makes this EPP repeatable so as to obtain a higher fidelity of logic entangled states. As the logic-qubit entanglement utilizes the quantum error correction (QEC) codes, which has an inherent stability against noise and decoherence, this EPP combined with the QEC codes may provide a double protection for the entanglement from the channel noise and may have potential applications in long-distance quantum communication.
Transition from moving to stationary double layers in a single-ended Q machine
NASA Technical Reports Server (NTRS)
Song, Bin; Merlino, R. L.; D'Angelo, N.
1990-01-01
Large-amplitude (less than about 100 percent) relaxation oscillations in the plasma potential are known to be generated when the cold endplate of a single-ended Q machine is biased positively. These oscillations are associated with double layers that form near the hot plate (plasma source) and travel toward the endplate at about the ion-acoustic velocity. At the endplate they dissolve and then form again near the hot plate, the entire process repeating itself in a regular manner. By admitting a sufficient amount of neutral gas into the system, the moving double layers were slowed down and eventually stopped. The production of stationary double layers requires an ion source on the high-potential side of the double layers. These ions are provided by ionization of the neutral gas by electrons that are accelerated through the double layer. The dependence of the critical neutral gas pressure required for stationary double-layer formation on endplate voltage, magnetic field strength, and neutral atom mass has been examined. These results are discussed in terms of a simple model of ion production and loss, including ion losses across the magnetic field.
The permeability of the endplate channel to organic cations in frog muscle
1980-01-01
The relative permeability of endplate channels to many organic cations was determined by reversal-potential criteria. Endplate currents induced by iontophoretic "puffs" of acetylcholine were studied by a Vaseline gap, voltage clamp method in cut muscle fibers. Reversal potential changes were measured as the NaCl of the bathing medium was replaced by salts of organic cations, and permeability ratios relative to Na+ ions were calculated from the Goldman-Hodgkin-Katz equation. 40 small monovalent organic cations had permeability ratios larger than 0.1. The most permeant including NH4+, hydroxylamine, hydrazine, methylamine, guanidine, and several relatives of guanidine had permeability ratios in the range 1.3--2.0. However, even cations such as imidazole, choline, tris(hydroxymethyl)aminomethane, triethylamine, and glycine methylester were appreciably permeant with permeability ratios of 0.13--0.95. Four compounds with two charged nitrogen groups were also permeant. Molecular models of the permeant ions suggest that the smallest cross-section of the open pore must be at least as large as a square, 6.5 A x 6.5 A. Specific chemical factors seem to be less important than access or friction in determining the ionic selectivity of the endplate channel. PMID:6247422
Presynaptic pH and vesicle fusion in Drosophila larvae neurones.
Caldwell, Lesley; Harries, Peter; Sydlik, Sebastian; Schwiening, Christof J
2013-11-01
Both intracellular pH (pHi) and synaptic cleft pH change during neuronal activity yet little is known about how these pH shifts might affect synaptic transmission by influencing vesicle fusion. To address this we imaged pH- and Ca(2+) -sensitive fluorescent indicators (HPTS, Oregon green) in boutons at neuromuscular junctions. Electrical stimulation of motor nerves evoked presynaptic Ca(2+) i rises and pHi falls (∼0.1 pH units) followed by recovery of both Ca(2+) i and pHi. The plasma-membrane calcium ATPase (PMCA) inhibitor, 5(6)-carboxyeosin diacetate, slowed both the calcium recovery and the acidification. To investigate a possible calcium-independent role for the pHi shifts in modulating vesicle fusion we recorded post-synaptic miniature end-plate potential (mEPP) and current (mEPC) frequency in Ca(2+) -free solution. Acidification by propionate superfusion, NH(4)(+) withdrawal, or the inhibition of acid extrusion on the Na(+)/H(+) exchanger (NHE) induced a rise in miniature frequency. Furthermore, the inhibition of acid extrusion enhanced the rise induced by propionate addition and NH(4)(+) removal. In the presence of NH(4)(+), 10 out of 23 cells showed, after a delay, one or more rises in miniature frequency. These findings suggest that Ca(2+) -dependent pHi shifts, caused by the PMCA and regulated by NHE, may stimulate vesicle release. Furthermore, in the presence of membrane permeant buffers, exocytosed acid or its equivalents may enhance release through positive feedback. This hitherto neglected pH signalling, and the potential feedback role of vesicular acid, could explain some important neuronal excitability changes associated with altered pH and its buffering. Copyright © 2013 Wiley Periodicals, Inc.
Sagittal endplate morphology of the lower lumbar spine.
Lakshmanan, Palaniappan; Purushothaman, Balaji; Dvorak, Vlasta; Schratt, Walter; Thambiraj, Sathya; Boszczyk, Maximilian
2012-05-01
The sagittal profile of lumbar endplates is discrepant from current simplified disc replacement and fusion device design. Endplate concavity is symmetrical in the coronal plane but shows considerable variability in the sagittal plane, which may lead to implant-endplate mismatch. The aim of this investigation is to provide further analysis of the sagittal endplate morphology of the mid to lower lumbar spine study (L3–S1), thereby identifying the presence of common endplate shape patterns across these levels and providing morphological reference values complementing the findings of previous studies. Observational study. A total of 174 magnetic resonance imaging (MRI) scans of the adult lumbar spine from the digital archive of our centre, which met the inclusion criteria, were studied. Superior (SEP) and inferior (IEP) endplate shape was divided into flat (no concavity), oblong (homogeneous concavity) and ex-centric (inhomogeneous concavity). The concavity depth (ECD) and location of concavity apex (ECA) relative to endplate diameter of the vertebrae L3–S1 were determined. Flat endplates were only predominant at the sacrum SEP (84.5%). The L5 SEP was flat in 24.7% and all other endplates in less than 10%. The majority of endplates were concave with a clear trend of endplate shape becoming more ex-centric from L3 IEP (56.9% oblong vs. 37.4% ex-centric) to L5 IEP (4% oblong vs. 94.3% ex-centric). Ex-centric ECA were always found in the posterior half of the lumbar endplates. Both the oblong and ex-centric ECD was 2-3 mm on average with the IEP of a motion segment regularly possessing the greater depth. A sex- or age-related difference could not be found. The majority of lumbar endplates are concave, while the majority of sacral endplates are flat. An oblong and an ex-centric endplate shape can be distinguished, whereby the latter is more common at the lower lumbar levels. The apex of the concavity of ex-centric discs is located in the posterior half of the endplate and the concavity of the inferior endplate is deeper than that of the superior endplate. Based on the above, the current TDR and ALIF implant design does not sufficiently match the morphology of lumbar endplates in the sagittal plane.
New support for an old hypothesis: density affects extra-pair paternity
Mayer, Christian; Pasinelli, Gilberto
2013-01-01
Density has been suggested to affect variation in extra-pair paternity (EPP) in avian mating systems, because increasing density promotes encounter rates and thus mating opportunities. However, the significance of density affecting EPP variation in intra- and interspecific comparisons has remained controversial, with more support from intraspecific comparisons. Neither experimental nor empirical studies have consistently provided support for the density hypothesis. Testing the density hypothesis is challenging because density measures may not necessarily reflect extra-pair mating opportunities, mate guarding efforts may covary with density, populations studied may differ in migratory behavior and/or climatic conditions, and variation in density may be insufficient. Accounting for these potentially confounding factors, we tested whether EPP rates within and among subpopulations of the reed bunting (Emberiza schoeniclus) were related to density. Our analyses were based on data from 13 subpopulations studied over 4 years. Overall, 56.4% of totally 181 broods contained at least one extra-pair young (EPY) and 37.1% of totally 669 young were of extra-pair origin. Roughly 90% of the extra-pair fathers were from the adjacent territory or from the territory after the next one. Within subpopulations, the proportion of EPY in broods was positively related to local breeding density. Similarly, among subpopulations, proportion of EPY was positively associated with population density. EPP was absent in subpopulations consisting of single breeding pairs, that is, without extra-pair mating opportunities. Our study confirms that density is an important biological factor, which significantly influences the amount of EPP within and among subpopulations, but also suggests that other mechanisms influence EPP beyond the variation explained by density. PMID:23533071
NASA Astrophysics Data System (ADS)
Jung, Jae Hwan; Kim, Mi Jeong; Yoon, Hyun Sik; Hung, Pham Anh; Chun, Ho Hwan; Park, Dong Woo
2012-12-01
We investigated the aerodynamic characteristics of a three-dimensional (3D) wing with an endplate in the vicinity of the free surface by solving incompressible Navier-Stokes equations with the turbulence closure model. The endplate causes a blockage effect on the flow, and an additional viscous effect especially near the endplate. These combined effects of the endplate significantly reduce the magnitudes of the velocities under the lower surface of the wing, thereby enhancing aerodynamic performance in terms of the force coefficients. The maximum lift-to-drag ratio of a wing with an endplate is increased 46% compared to that of wing without an endplate at the lowest clearance. The tip vortex of a wing-with-endplate (WWE) moved laterally to a greater extent than that of a wing-without-endplate (WOE). This causes a decrease in the induced drag, resulting in a reduction in the total drag.
Imaging Electron Spectrometer (IES) Electron Preprocessor (EPP) Design
NASA Technical Reports Server (NTRS)
Fennell, J. F.; Osborn, J. V.; Christensen, John L. (Technical Monitor)
2001-01-01
The Aerospace Corporation developed the Electron PreProcessor (EPP) to support the Imaging Electron Spectrometer (IES) that is part of the RAPID experiment on the ESA/NASA CLUSTER mission. The purpose of the EPP is to collect raw data from the IES and perform processing and data compression on it before transferring it to the RAPID microprocessor system for formatting and transmission to the CLUSTER satellite data system. The report provides a short history of the RAPID and CLUSTER programs and describes the EPP design. Four EPP units were fabricated, tested, and delivered for the original CLUSTER program. These were destroyed during a launch failure. Four more EPP units were delivered for the CLUSTER II program. These were successfully launched and are operating nominally on orbit.
Kishida, Kazuki; Ohkusu-Tsukada, Kozo; Hori, Makito; Konnai, Masaki; Abiko, Chieko; Suzuki, Yoshikazu; Yamanome, Yukito; Yoshimura, Hisashi; Michishita, Masaki; Takahashi, Kimimasa
2013-05-01
Intrahepatic eosinophilic proliferative pylephlebitis (EPP) in Japanese Black (JB) cattle generally has been considered to be an atypical form of fascioliasis. However, there are many cases of EPP in which no Fasciola spp. have been detected in the livers of affected cattle. The aims of this study were to ascertain the relationship between EPP and hepatic fascioliasis and to investigate the role of food allergy in the disease. Histologically, EPP lesions were characterised by severe endothelial proliferation of the interlobular veins, accompanied by varying degrees of fibrosis and eosinophilic infiltration in portal areas, which could be differentiated from chronic cholangiohepatitis, the typical lesion of hepatic fascioliasis. In addition to hepatic lesions, all cases of EPP had varying degrees of eosinophilic infiltration in the perilymphoid red pulp of the spleen, whereas both affected and unaffected animals had eosinophilic infiltrates in the mucosa of the small intestine. Antibodies against Fasciola spp. were detected in 1/14 EPP cases by ELISA; the seropositive case had EPP in combination with chronic cholangitis. There was no significant difference in total concentration of IgE between cases of EPP and unaffected cattle. Serum IgE levels specific to curly dock (Rumex crispus) and oats (Avena sativa) were higher in EPP cases than in unaffected cattle by allergen profiling screening testing and ELISA. The results of this study suggest that hepatic fascioliasis is unlikely to be the cause of EPP in JB cattle and that food allergens should be investigated as possible aetiological agents. Copyright © 2012 Elsevier Ltd. All rights reserved.
Surface modification of polypropylene based particle foams
NASA Astrophysics Data System (ADS)
Schreier, P.; Trassl, C.; Altstädt, V.
2014-05-01
This paper deals with the modification of the surface properties of expanded polypropylene (EPP). EPP is a semi-hard to soft elastic thermoplastic foam. The characteristic surface of EPP shows process-related steam nozzle imprints and gussets. Therefore EPP does not satisfy the quality requirements for visible automotive applications. In order to meet these demands, plastic surfaces are usually enhanced with functional or decorative coatings, e.g. textiles, plastic films or paint. The coating of plastics with low surface energies such as PP often leads to adhesion problems by reason of the missing polar and functional groups. This paper gives an evaluation of activation and pre-treatment methods of EPP, with the aim to identify the most suitable pre-treatment method. For this purpose five typical surface treatment methods - flame treatment, corona, fluorination, atmospheric and low-pressure plasma - were performed on EPP samples. As a comparison criterion the maximum increase in the adhesion force between a polyurethane-based coating and the modified EPP substrate was selected. Moreover the influence of the selected pre-treatment method on the increase in the total surface energy and its polar component was investigated by the drop shape analysis method. The results showed that the contact angle measurement is a suitable method to determine the polar and disperse fractions of the surface tension of EPP. Furthermore, all performed methods increased the adhesion of EPP.
Direct EPP Affects on the Middle Atmosphere
NASA Technical Reports Server (NTRS)
Jackman, Charles H.
2011-01-01
Energetic precipitating particles (EPPs) can cause significant direct constituent changes in the mesosphere and stratosphere (middle atmosphere) during certain periods. Both protons and electrons can influence the polar middle atmosphere through ionization and dissociation processes. EPPs can enhance HOx (H, OH, HO2) through the formation of positive ions followed by complex ion chemistry and NOx (N, NO, NO2) through the dissociation of molecular nitrogen. The HOx increases result in direct ozone destruction in the mesosphere and upper stratosphere via several catalytic loss cycles. Such middle atmospheric HOx-caused ozone loss is rather short-lived due to the relatively short lifetime (hours) of the HOx constituents. The NOx family has a considerably longer lifetime than the HOx family and can also lead to catalytic ozone destruction. EPP-caused enhancements of the NOx family can affect ozone directly, if produced in the stratosphere. Ozone decreases from the EPPs lead to a reduction in atmospheric heating and, subsequent atmospheric cooling. Conversely, EPPs can cause direct atmospheric heating through Joule heating. Measured HOx constituents OH and HO2 showed increases due to solar protons. Observed NOx constituents NO and NO2 were enhanced due to both solar protons and precipitating electrons. Other hydrogen- and nitrogen-ocntaining constituents were also measured to be directly influenced by EPPs, including N2O, HNO3, HO2NO2, N2OS, H2O2, ClONO2, HCl, and HOCl. Observed constituents ClO and CO were directly affected by EPPs as well. Many measurements indicated significant direct ozone decreases. A significant number of satellites housed instruments, which observed direct EPP-caused atmospheric effects, including Nimbus 4 (BUV), Nimbus 7 (SBUV), several NOAA platforms (SBUV/2), SME, UARS (HALOE, CLAES), SCISAT-1 (ACE-FTS), Odin (OSIRIS), Envisat-l (GOMOS, MIPAS, SCIAMACHY), and Aura (MLS). Measurements by rockets and ground-based radar also indicated EPP direct impacts. Atmospheric models have been used with some success in predicting the direct EPP impacts on the mesosphere and stratosphere. A review of the observed direct effects of EPP on the middle atmosphere will be given in this presentation.
In vitro comparison of endplate preparation between four mini-open interbody fusion approaches.
Tatsumi, Robert; Lee, Yu-Po; Khajavi, Kaveh; Taylor, William; Chen, Foster; Bae, Hyun
2015-04-01
Discectomy and endplate preparation are important steps in interbody fusion for ensuring sufficient arthrodesis. While modern less-invasive approaches for lumbar interbody fusion have gained in popularity, concerns exist regarding their ability to allow for adequate disc space and endplate preparation. Thus, the purpose of this study was to quantitatively and qualitatively evaluate and compare disc space and endplate preparation achieved with four less-invasive approaches for lumbar interbody fusion in cadaveric spines. A total of 24 disc spaces (48 endplates) from L2 to L5 were prepared in eight cadaveric torsos using mini-open anterior lumbar interbody fusion (mini-ALIF), minimally invasive posterior lumbar interbody fusion (MAS PLIF), minimally invasive transforaminal lumbar interbody fusion (MAS TLIF) or minimally invasive lateral, transpsoas interbody fusion (XLIF) on two specimens each, for a total of six levels and 12 endplates prepared per procedure type. Following complete discectomy and endplate preparation, spines were excised and split axially at the interbody disc spaces. Endplates were digitally photographed and evaluated using image analysis software. Area of endplate preparation was measured and qualitative evaluation was also performed to grade the quality of preparation. The XLIF approach resulted in the greatest relative area of endplate preparation (58.3 %) while mini-ALIF resulted in the lowest at 35.0 %. Overall, there were no differences in percentage of preparation between cranial and caudal endplates, though this was significantly different in the XLIF group (65 vs 52 %, respectively). ALL damage was observed in 3 MAS TLIF levels. Percentage of endplate that was deemed to have complete disc removal was highest in XLIF group with 90 % compared to 65 % in MAS TLIF group, 43 % in MAS PLIF, and 40 % in mini-ALIF group. Endplate damage area was highest in the MAS TLIF group at 48 % and lowest in XLIF group at 4 %. These results demonstrate that adequate endplate preparation for interbody fusion can be achieved utilizing various minimally invasive approach techniques (mini-ALIF, MAS TLIF, MAS PLIF, XLIF), however, XLIF appears to provide a greater area of and more complete endplate preparation.
Youssef, J A; McKinley, T O; Yerby, S A; McLain, R F
1999-06-01
A bending analysis of pedicle screws inserted into vertebral body analogues. Intravertebral and intrapedicular pedicle screw bending moments were studied as a function of sagittal insertion angle. To determine how the pedicle screw bending moment is affected by changes in the insertion angle. There is a significant incidence of failure when pedicle screws are used to instrument unstable spinal segments. Extrinsic factors that affect screw bending failure have been poorly characterized. Previous work has demonstrated that intrapedicular pedicle screw bending moments are significantly affected by the sagittal location and depth of pedicle screw placement. Pedicle screw transducers were inserted in analogue vertebrae at one of three orientations: 7 degrees cephalad (toward the superior endplate), 7 degrees caudal (toward the inferior endplate), or parallel to the superior endplate (control). An axial load was applied to the superior endplate of the vertebra, and screw bending moments were recorded directly from the transducers. Screws angled 7 degrees cephalad developed significantly greater mean intrapedicular bending moments compared with screws inserted caudal or control screws. There was no significant difference in bending moments realized within the vertebral body for the three screw positions. Angulating pedicle screws toward the superior endplate increased bending moments within the pedicle. If attention to optimal screw insertion technique can reduce bending moments and potential for screw failure without increasing morbidity, surgical risk, or operative time, then proper insertion technique takes on new importance.
Electromagnetic Analysis of ITER Diagnostic Equatorial Port Plugs During Plasma Disruptions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Y. Zhai, R. Feder, A. Brooks, M. Ulrickson, C.S. Pitcher and G.D. Loesser
2012-08-27
ITER diagnostic port plugs perform many functionsincluding structural support of diagnostic systems under high electromagnetic loads while allowing for diagnostic access to the plasma. The design of diagnostic equatorial port plugs (EPP) are largely driven by electromagnetic loads and associate responses of EPP structure during plasma disruptions and VDEs. This paper summarizes results of transient electromagnetic analysis using Opera 3d in support of the design activities for ITER diagnostic EPP. A complete distribution of disruption loads on the Diagnostic First Walls (DFWs), Diagnostic Shield Modules (DSMs) and the EPP structure, as well as impact on the system design integration duemore » to electrical contact among various EPP structural components are discussed.« less
Levin, Lia; Sefati, Noga
2018-04-23
Unemployment is a harsh social phenomenon with far reaching negative implications. Unemployed individuals often seek assistance from social workers working in Municipal Departments of Social Services around the world. However, little to no research exists on the factors involved in social workers' choice to engage in employment-promoting practices (EPP). The current study aimed to tackle this gap of knowledge, providing initial conclusions about the relationship between social workers' attitudes towards unemployment, their knowledge regarding EPP, the extent to which they perceive their organisations as endorsing EPP and their actual implementation. The main research question dealt with the extent to which each of the examined factors, in itself or in combination with others, would be the best predictor of social workers' utilisation of EPP. The study sample consisted of 163 social workers in Israel with varied experience in working with the unemployed, all working in public sector social services. Structural equation modelling performed on the attained data revealed that knowledge, skills and perceived organisational endorsement of EPP were positively associated with implementation of EPP. Contrary to the hypothesised, attitudes towards unemployment were not associated with the implementation of such practices. At the same time, professional training and seniority were associated with EPP only through the mediation of perceived organisational endorsement. Ultimately, perceived organisational endorsement of EPP emerged as the most influential factor involved in social workers' decision to carry out EPP with their service-users. Consequences of these findings for social work education, supervision, research and policy making are discussed, referring to the local Israeli context as well as its possible international inferences. © 2018 John Wiley & Sons Ltd.
Electromagnetic Analysis For The Design Of ITER Diagnostic Port Plugs During Plasma Disruptions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhai, Y
2014-03-03
ITER diagnostic port plugs perform many functions including structural support of diagnostic systems under high electromagnetic loads while allowing for diagnostic access to plasma. The design of diagnotic equatorial port plugs (EPP) are largely driven by electromagnetic loads and associate response of EPP structure during plasma disruptions and VDEs. This paper summarizes results of transient electromagnetic analysis using Opera 3d in support of the design activities for ITER diagnostic EPP. A complete distribution of disruption loads on the Diagnostic First Walls (DFWs). Diagnostic Shield Modules (DSMs) and the EPP structure, as well as impact on the system design integration duemore » to electrical contact among various EPP structural components are discussed.« less
Bansode, Vijay B.; Koentgen, Frank; Trüb, Judith; Pelczar, Pawel; Schneider-Yin, Xiaoye; Minder, Elisabeth I.
2017-01-01
ABSTRACT Erythropoietic protoporphyria (EPP) is caused by deficiency of ferrochelatase (FECH), which incorporates iron into protoporphyrin IX (PPIX) to form heme. Excitation of accumulated PPIX by light generates oxygen radicals that evoke excessive pain and, after longer light exposure, cause ulcerations in exposed skin areas of individuals with EPP. Moreover, ∼5% of the patients develop a liver dysfunction as a result of PPIX accumulation. Most patients (∼97%) have a severe FECH mutation (Mut) in trans to an intronic polymorphism (c.315-48C), which reduces ferrochelatase synthesis by stimulating the use of an aberrant 3′ splice site 63 nt upstream of the normal site for exon 4. In contrast, with the predominant c.315-48T allele, the correct splice site is mostly used, and individuals with a T/Mut genotype do not develop EPP symptoms. Thus, the C allele is a potential target for therapeutic approaches that modify this splicing decision. To provide a model for pre-clinical studies of such approaches, we engineered a mouse containing a partly humanized Fech gene with the c.315-48C polymorphism. F1 hybrids obtained by crossing these mice with another inbred line carrying a severe Fech mutation (named m1Pas) show a very strong EPP phenotype that includes elevated PPIX in the blood, enlargement of liver and spleen, anemia, as well as strong pain reactions and skin lesions after a short period of light exposure. In addition to the expected use of the aberrant splice site, the mice also show a strong skipping of the partly humanized exon 3. This will limit the use of this model for certain applications and illustrates that engineering of a hybrid gene may have unforeseeable consequences on its splicing. PMID:28093505
Recovering Wood and McCarthy's ERP-prototypes by means of ERP-specific procrustes-rotation.
Beauducel, André
2018-02-01
The misallocation of treatment-variance on the wrong component has been discussed in the context of temporal principal component analysis of event-related potentials. There is, until now, no rotation-method that can perfectly recover Wood and McCarthy's prototypes without making use of additional information on treatment-effects. In order to close this gap, two new methods: for component rotation were proposed. After Varimax-prerotation, the first method identifies very small slopes of successive loadings. The corresponding loadings are set to zero in a target-matrix for event-related orthogonal partial Procrustes- (EPP-) rotation. The second method generates Gaussian normal distributions around the peaks of the Varimax-loadings and performs orthogonal Procrustes-rotation towards these Gaussian distributions. Oblique versions of this Gaussian event-related Procrustes- (GEP) rotation and of EPP-rotation are based on Promax-rotation. A simulation study revealed that the new orthogonal rotations recover Wood and McCarthy's prototypes and eliminate misallocation of treatment-variance. In an additional simulation study with a more pronounced overlap of the prototypes GEP Promax-rotation reduced the variance misallocation slightly more than EPP Promax-rotation. Comparison with Existing Method(s): Varimax- and conventional Promax-rotations resulted in substantial misallocations of variance in simulation studies when components had temporal overlap. A substantially reduced misallocation of variance occurred with the EPP-, EPP Promax-, GEP-, and GEP Promax-rotations. Misallocation of variance can be minimized by means of the new rotation methods: Making use of information on the temporal order of the loadings may allow for improvements of the rotation of temporal PCA components. Copyright © 2017 Elsevier B.V. All rights reserved.
Barriers faced by expanded practice dental hygienists in Oregon.
Coplen, Amy E; Bell, Kathryn P
2015-04-01
Oregon allows dental hygienists to provide services without the supervision of a dentist if they hold an expanded practice permit (EPP). This study surveyed practicing and non-practicing EPP holders with the purpose of assessing perceived barriers to practicing independently and better educating students to begin independent practice upon graduation. A survey was developed, approved by the institutional review board and pilot tested with current Expanded Practice Dental Hygienists (EPDHs). A list of EPDHs was obtained from the Oregon State Dental Board, and 181 surveys were mailed in November 2011. The response rate was 39% (n=71). Data from this study indicate a large number of new EPP holders, with 62% (n=41) holding their permit for 3 years or less, but only 41% (n=29) of respondents are actually providing care in a setting requiring an EPP. Responding practicing EPDHs reported barriers including: challenges with insurance reimbursement, lack of knowledge/acceptance, equipment cost/maintenance, difficulty obtaining a collaborative agreement/cooperating facility, advertising and inability to make a living wage. Responding non-practicing EPDHs reported barriers including: currently working in another setting, lack of business knowledge, time, start-up cost, inability to make a living wage, lack of opportunity, reimbursement difficulties and lack of experience. Perceived barriers to practicing independently differ between those practicing utilizing their EPP and those not practicing. Ways to eliminate barriers for both practicing and non-practicing EPDHs should be explored. There is potential to reduce the barriers to independent practice through curricular changes, public health partnerships among EPDHs, and new health care systems that specifically address barriers found through this study. Copyright © 2015 The American Dental Hygienists’ Association.
Atmospheric Effects of Energetic Particle Precipitation in the Arctic Winter 1978-1979 Revisited
NASA Technical Reports Server (NTRS)
Holt, L. A.; Randall, C. E.; Harvey, V. L.; Remsberg, E. E.; Stiller, G. P.; Funke, B.; Bernath, P. F.; Walker, K. A.
2012-01-01
The Limb Infrared Monitor of the Stratosphere (LIMS) measured polar stratospheric enhancements of NO2 mixing ratios due to energetic particle precipitation (EPP) in the Arctic winter of 1978-1979. Recently reprocessed LIMS data are compared to more recent measurements from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) and the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) to place the LIMS measurements in the context of current observations. The amount of NOx (NO + NO2) entering the stratosphere that has been created by EPP in the mesosphere and lower thermosphere (EPP-NOx) has been quantified for the 1978-1979 and 2002-2003 through 2008-2009 Arctic winters. The NO2 enhancements in the LIMS data are similar to those in MIPAS and ACE-FTS data in the Arctic winters of 2002-2003, 2004-2005, 2006-2007, and 2007-2008. The largest enhancement by far is in 2003-2004 (approximately 2.2 Gmol at 1500 K), which is attributed to a combination of elevated EPP and unusual dynamics that led to strong descent in the upper stratosphere/lower mesosphere in late winter. The enhancements in 2005-2006 and 2008-2009, during which large stratospheric NOx enhancements were caused by a dynamical situation similar to that in 2003 2004, are larger than in all the other years (except 2003-2004) at 3000 K. However, by 2000 K the enhancements in 2005-2006 (2008-2009) are on the same order of magnitude as (smaller than) all other years. These results highlight the importance of the timing of the descent in determining the potential of EPP-NOx for reaching the middle stratosphere.
Gong, Lin; Jiang, Changqing; Liu, Li; Wan, Shengxiang; Tan, Wen; Ma, Sushuang; Jia, Xiaojian; Wang, Meiwei; Hu, Azhen; Shi, Yu; Zhang, Yu; Shen, Yuanyuan; Wang, Feng; Chen, Yun
2018-01-01
Neurotrophin-3 (NT-3) has potential as a therapeutic agent for the treatment of patients with denervated muscle atrophy. However, the endogenous secretion of NT-3 is low and exogenous NT-3 lacks sufficient time to accumulate due to its short half-life. The transfection of NT-3 has been demonstrated to have a beneficial effect on denervated muscle and motor endplates. Neural stem cells (NSCs) differentiate into neurons and form motor endplate nerve-muscle connections. It has been previously demonstrated that local and noninvasive transfection can be performed using ultrasound with microbubbles (MBs). In the current study, hematoxylin and eosin, acetylcholinesterase and gold chloride staining, as well as transmission electron microscopy, were performed to verify the effects of this treatment strategy. The results demonstrated that using ultrasound with MBs for the transfection of NT-3 into NSCs, and their subsequent transplantation in vivo , attenuated the atrophy of denervated muscle and reduced motor endplate degeneration. This noninvasive, efficient and targeted treatment strategy may therefore be a potential treatment for patients with denervated muscle atrophy.
Rhee, Wootack; Ha, Seongil; Lim, Jae Hyeon; Jang, Il Tae
2014-01-01
Objective Using alendronate after spinal fusion is a controversial issue due to the inhibition of osteoclast mediated bone resorption. In addition, there are an increasing number of reports that the endplate degeneration influences the lumbar spinal fusion. The object of this retrospective controlled study was to evaluate how the endplate degeneration and the bisphosphonate medication influence the spinal fusion through radiographic evaluation. Methods In this study, 44 patients who underwent single-level posterior lumbar interbody fusion (PLIF) using cage were examined from April 2007 to March 2009. All patients had been diagnosed as osteoporosis and would be recommended for alendronate medication. Endplate degeneration is categorized by the Modic changes. The solid fusion is defined if there was bridging bone between the vertebral bodies, either within or external to the cage on the plain X-ray and if there is less than 5° of angular difference in dynamic X-ray. Results In alendronate group, fusion was achieved in 66.7% compared to 73.9% in control group (no medication). Alendronate did not influence the fusion rate of PLIF. However, there was the statistical difference of fusion rate between the endplate degeneration group and the group without endplate degeneration. A total of 52.4% of fusion rate was seen in the endplate degeneration group compared to 91.3% in the group without endplate degeneration. The endplate degeneration suppresses the fusion process of PLIF. Conclusion Alendronate does not influence the fusion process in osteoporotic patients. The endplate degeneration decreases the fusion rate. PMID:25620981
NASA Astrophysics Data System (ADS)
Asikainen, T.; Salminen, A.; Maliniemi, V.; Mursula, K.
2017-12-01
Energetic particle precipitation (EPP) has been shown to cause ozone loss in the stratosphere during polar winter. This has been suggested to enhance polar vortex with the effect propagating even to ground level, where it is observed as a more positive phase of the Northern Annular Mode (NAM), the dominant ground circulation pattern in the winter time at high latitudes. Recent research has also shown that the quasi-biennial oscillation (QBO) modulates the relationship between the ground NAM and EPP so that the positive correlation between the two is more clearly seen in the easterly phase of QBO measured at 30 hPa height especially during the late winter season. Here we elaborate the QBO modulated connection between EPP and NAM by studying how the EPP affects the stratospheric polar vortex in the two phases of the QBO. Since the EPP presumably affects the polar stratosphere via indirect ozone loss we will study how the EPP modulates the amount of ozone, the stratospheric temperatures and zonal winds in the two QBO phases.
NASA Astrophysics Data System (ADS)
Salminen, Antti; Asikainen, Timo; Maliniemi, Ville; Mursula, Kalevi
2017-04-01
Energetic particle precipitation (EPP) has been shown to cause ozone loss in the stratosphere during polar winter. This has been suggested to enhance polar vortex with the effect propagating even to ground level, where it is observed as a more positive phase of the Northern Annular Mode (NAM), the dominant ground circulation pattern in the winter time at high latitudes. Recent research has also shown that the quasi-biennial oscillation (QBO) modulates the relationship between the ground NAM and EPP so that the positive correlation between the two is more clearly seen in the easterly phase of QBO measured at 30 hPa height especially during the late winter season. Here we elaborate the QBO modulated connection between EPP and NAM by studying how the EPP affects the stratospheric polar vortex in the two phases of the QBO. Since the EPP presumably affects the polar stratosphere via indirect ozone loss we will study how the EPP modulates the amount of ozone, the stratospheric temperatures and zonal winds in the two QBO phases.
Tzermiadianos, Michael N.; Renner, Susan M.; Phillips, Frank M.; Hadjipavlou, Alexander G.; Zindrick, Michael R.; Havey, Robert M.; Voronov, Michael
2008-01-01
This study investigated the effect of endplate deformity after an osteoporotic vertebral fracture in increasing the risk for adjacent vertebral fractures. Eight human lower thoracic or thoracolumbar specimens, each consisting of five vertebrae were used. To selectively fracture one of the endplates of the middle VB of each specimen a void was created under the target endplate and the specimen was flexed and compressed until failure. The fractured vertebra was subjected to spinal extension under 150 N preload that restored the anterior wall height and vertebral kyphosis, while the fractured endplate remained significantly depressed. The VB was filled with cement to stabilize the fracture, after complete evacuation of its trabecular content to ensure similar cement distribution under both the endplates. Specimens were tested in flexion-extension under 400 N preload while pressure in the discs and strain at the anterior wall of the adjacent vertebrae were recorded. Disc pressure in the intact specimens increased during flexion by 26 ± 14%. After cementation, disc pressure increased during flexion by 15 ± 11% in the discs with un-fractured endplates, while decreased by 19 ± 26.7% in the discs with the fractured endplates. During flexion, the compressive strain at the anterior wall of the vertebra next to the fractured endplate increased by 94 ± 23% compared to intact status (p < 0.05), while it did not significantly change at the vertebra next to the un-fractured endplate (18.2 ± 7.1%, p > 0.05). Subsequent flexion with compression to failure resulted in adjacent fracture close to the fractured endplate in six specimens and in a non-adjacent fracture in one specimen, while one specimen had no adjacent fractures. Depression of the fractured endplate alters the pressure profile of the damaged disc resulting in increased compressive loading of the anterior wall of adjacent vertebra that predisposes it to wedge fracture. This data suggests that correction of endplate deformity may play a role in reducing the risk of adjacent fractures. PMID:18795344
Correlation of cervical endplate strength with CT measured subchondral bone density
Ordway, Nathaniel R.; Lu, Yen-Mou; Zhang, Xingkai; Cheng, Chin-Chang; Fang, Huang
2007-01-01
Cervical interbody device subsidence can result in screw breakage, plate dislodgement, and/or kyphosis. Preoperative bone density measurement may be helpful in predicting the complications associated with anterior cervical surgery. This is especially important when a motion preserving device is implanted given the detrimental effect of subsidence on the postoperative segmental motion following disc replacement. To evaluate the structural properties of the cervical endplate and examine the correlation with CT measured trabecular bone density. Eight fresh human cadaver cervical spines (C2–T1) were CT scanned and the average trabecular bone densities of the vertebral bodies (C3–C7) were measured. Each endplate surface was biomechanically tested for regional yield load and stiffness using an indentation test method. Overall average density of the cervical vertebral body trabecular bone was 270 ± 74 mg/cm3. There was no significant difference between levels. The yield load and stiffness from the indentation test of the endplate averaged 139 ± 99 N and 156 ± 52 N/mm across all cervical levels, endplate surfaces, and regional locations. The posterior aspect of the endplate had significantly higher yield load and stiffness in comparison to the anterior aspect and the lateral aspect had significantly higher yield load in comparison to the midline aspect. There was a significant correlation between the average yield load and stiffness of the cervical endplate and the trabecular bone density on regression analysis. Although there are significant regional variations in the endplate structural properties, the average of the endplate yield loads and stiffnesses correlated with the trabecular bone density. Given the morbidity associated with subsidence of interbody devices, a reliable and predictive method of measuring endplate strength in the cervical spine is required. Bone density measures may be used preoperatively to assist in the prediction of the strength of the vertebral endplate. A threshold density measure has yet to be established where the probability of endplate fracture outweighs the benefit of anterior cervical procedure. PMID:17712574
NASA Astrophysics Data System (ADS)
Hoelscher, Mary Helen
While many lesbian, gay, bisexual, transgender, and queer (LGBTQ) students are able to resiliently navigate their public school education many others experience harsh school climates and negative health and educational outcomes. Harassment and bullying of LGBTQ students in school environments have been linked to numerous negative psychological and academic outcomes for students diverse in sexual orientation and/or gender identity. Preparing teacher candidates (TCs) to respond effectively to harassment and bullying of students and to create inclusive curriculum has been recommended to improve outcomes for students. Yet the development of these teaching practices has not been pursued broadly in educator preparation programs (EPPs) or specifically in science EPPs (SEPPs). This dissertation broadens the notion of diversity traditionally attended to in EPPs through three studies. The first study is a holistic single-case study of an LGBTQ-inclusive EPP. It focused on the following three research questions: What were the contextual features that surrounded the LGBTQ-inclusive EPP? What were the specific elements of LGBTQ inclusion in the EPP? And, what were the strengths and weaknesses of the LGBTQ-inclusive EPP? This study drew primarily from data collected from interviews with faculty and administrators in a large post-baccalaureate 5th year preparation for licensure program. Document analysis was used to triangulate and expand upon the data collected during the interviews. A framework for analyzing LGBTQ inclusion across the components of an EPP was developed as part of this study. This study has direct implications for the particular EPP, but also clarifies research needs around LGBTQ inclusion in secondary EPPs. While little has research exists about LGBTQ inclusion in EPPs, far less has been attempted and understood in the discipline of secondary life science. The second study thus narrows its focus from the particulars of LGBTQ inclusion in an EPP to the possibilities for LGBTQ inclusion in life science educator preparation. This study, thus, is theoretical as it sets about exploring possibilities for LGBTQ inclusion across life science education curriculum by drawing from the literature about the needs of LGBT and questioning students, the small amount of scholarly work related to science teacher education, and other scholarly work that relates to preparing teachers for gender and sexual diversity in secondary settings. The second study explored possibilities for LGBTQ inclusion in science teacher education. The third study, a holistic multiple-case study, explored science teacher candidates' adoption of LGBTQ inclusion in their praxis during a science EPP (SEPP). The research questions guiding this study were: what were science TCs' commitments to LGBTQ-inclusive praxis? What were science TCs' enactments of LGBTQ-inclusive praxis? And, what supports and barriers influenced TCs' commitment to and enactment of LGBTQ-inclusive praxis during the SEPP? Understanding these commitments, enactments, and the supports and barriers to them will benefit the particular SEPP and contribute to greater understanding of the capacities and needs of science TCs as they are challenged to fully welcome and educate the diversity of learners who enter their classrooms. The set of studies concludes with a discussion of implications for EPPs and future research that may lead to the realization of a vision of classroom practices that are inclusive of LGBTQ students for the benefit of schools and communities.
Oravec, Daniel; Quazi, Abrar; Xiao, Angela; Yang, Ellen; Zauel, Roger; Flynn, Michael J; Yeni, Yener N
2015-12-01
Endplate morphology is understood to play an important role in the mechanical behavior of vertebral bone as well as degenerative processes in spinal tissues; however, the utility of clinical imaging modalities in assessment of the vertebral endplate has been limited. The objective of this study was to evaluate the ability of two clinical imaging modalities (digital tomosynthesis, DTS; high resolution computed tomography, HRCT) to assess endplate topography by correlating the measurements to a microcomputed tomography (μCT) standard. DTS, HRCT, and μCT images of 117 cadaveric thoracolumbar vertebrae (T10-L1; 23 male, 19 female; ages 36-100 years) were segmented, and inferior and superior endplate surface topographical distribution parameters were calculated. Both DTS and HRCT showed statistically significant correlations with μCT approaching a moderate level of correlation at the superior endplate for all measured parameters (R(2)Adj=0.19-0.57), including averages, variability, and higher order statistical moments. Correlation of average depths at the inferior endplate was comparable to the superior case for both DTS and HRCT (R(2)Adj=0.14-0.51), while correlations became weak or nonsignificant for higher moments of the topography distribution. DTS was able to capture variations in the endplate topography to a slightly better extent than HRCT, and taken together with the higher speed and lower radiation cost of DTS than HRCT, DTS appears preferable for endplate measurements. Copyright © 2015 Elsevier Inc. All rights reserved.
Hyperconcavity of the lumbar vertebral endplates in the elite football lineman.
Moorman, Claude T; Johnson, David C; Pavlov, Helene; Barnes, Ronnie; Warren, Russell F; Speer, Kevin P; Guettler, Joseph H
2004-09-01
Hyperconcavity of the vertebral endplates is a previously unreported radiologic phenomenon. To analyze hyperconcavity of the vertebral endplates with expansion of the disk space in pre-National Football League lineman and to determine its clinical significance. Descriptive anatomical study. Over a 2-year period (1992-1993), 266 elite football linemen were evaluated at the National Football League scouting combine held in Indianapolis, Indiana. Evaluation focused on the lumbosacral spine and included history, physical examination, and lateral radiographs. Measurements were taken of all the vertebral endplate defects of involved vertebrae and compared with an age-matched control group of 110 patients. The analyzed data revealed the following: (1) hyperconcavity of the vertebral endplates appeared as a distinct entity in a high percentage of pre-National Football League lineman (33%) compared with age-matched controls (8%), (2) there was a trend toward a lower incidence of lumbosacral spine symptoms in those players who displayed hyperconcavity of the vertebral endplates (16%) versus those who did not (25%), and (3) when hyperconcavity of the vertebral endplates was present, all 5 lumbosacral disk spaces were commonly affected. Hyperconcavity of the vertebral endplates and hypertrophy of the disk space are likely adaptive changes occurring over time in response to the repetitive high loading and axial stress experienced in football line play.
Antosh, Ivan J; DeVine, John G; Carpenter, Clyde T; Woebkenberg, Brian J; Yoest, Stephen M
2010-12-01
Disc arthroplasty is an alternative to fusion following anterior discectomy when treating either cervical radiculopathy or myelopathy. Its theoretical benefits include preservation of the motion segment and the potential prevention of adjacent-segment degeneration. There is a paucity of data regarding the ability to use MR imaging to evaluate the adjacent segments. The purpose of this study was for the authors to introduce open MR imaging as an alternative method in imaging adjacent segments following cervical disc arthroplasty using a Co-Cr implant and to report their preliminary results using this technique. Postoperative cervical MR images were obtained in the first 16 patients in whom the porous coated motion (PCM-V) cervical arthroplasty system was used to treat a single level between C-3 and C-7. Imaging was performed in all 16 patients with a closed 1.5-T unit, and in the final 6 patients it was also performed with an open 0.2-T unit. All images were evaluated by an independent radiologist observer for the ability to visualize the superior endplate, disc space, and inferior endplate at the superior and inferior adjacent levels. Utilizing the 1.5-T magnet to assess the superior adjacent level, the superior endplate, disc space, and inferior endplate could each be visualized less than 50% of the time on sagittal T1- and sagittal and axial T2-weighted images. Similarly, the inferior adjacent level structures were adequately visualized less than 50% of the time, with the exception of slightly improved visualization of the inferior endplate on T1-weighted images (56%). Axial images allowed worse visualization than sagittal images at both the superior and inferior adjacent levels. Utilizing the 0.2-T magnet to assess the superior and inferior adjacent levels, the superior endplate, disc space, and inferior endplate were adequately visualized in 100% of images. Based on the results of this case series, it appears that the strength of the magnet affects the artifact from the Co-Cr endplates. The open 0.2-T MR imaging unit reduces artifact at adjacent levels after cervical disc arthroplasty without a significant reduction in the image quality. Magnetic resonance imaging can be used to evaluate the adjacent segments after disc arthroplasty if magnet strength is addressed, providing another means to assess the long-term efficacy of this novel treatment.
Sassa, S; Zalar, G L; Poh-Fitzpatrick, M B; Anderson, K E; Kappas, A
1982-01-01
In this paper we show that the ferrochelatase defect in erythropoietic protoporphyria (EPP) can readily be identified in mitogen-stimulated lymphocytes since such cells from patients with EPP accumulate approximately twice as much protoporphyrin IX as cells from normal subjects when incubated with a porphyrin precursor, gamma-aminolevulinic acid (ALA). Treatment of cultures with ALA and with the iron chelator, CaMgEDTA significantly increased the level of protoporphyrin IX in mitogen-stimulated lymphocytes from normal subjects, while the same treatment failed to produce an increase in protoporphyrin IX in cell preparations from EPP patients. In contrast to the results with the chelator treatment, supplementation of the cultures with iron and ALA reduced the level of protoporphyrin IX in normal cells, but not in EPP cells. These findings are compatible with a partial deficiency of ferrochelatase in EPP lymphocytes. The gene defects of acute intermittent porphyria and hereditary coproporphyria have previously been identified using lymphocyte preparations from the gene carriers of these diseases. The present study demonstrates that EPP represents another form of human porphyria in which the gene defect of the disease can now be identified in lymphocyte preparations. PMID:6804493
FY17 Status Report on the Initial EPP Finite Element Analysis of Grade 91 Steel
DOE Office of Scientific and Technical Information (OSTI.GOV)
Messner, M. C.; Sham, T. -L.
This report describes a modification to the elastic-perfectly plastic (EPP) strain limits design method to account for cyclic softening in Gr. 91 steel. The report demonstrates that the unmodified EPP strain limits method described in current ASME code case is not conservative for materials with substantial cyclic softening behavior like Gr. 91 steel. However, the EPP strain limits method can be modified to be conservative for softening materials by using softened isochronous stress-strain curves in place of the standard curves developed from unsoftened creep experiments. The report provides softened curves derived from inelastic material simulations and factors describing the transformationmore » of unsoftened curves to a softened state. Furthermore, the report outlines a method for deriving these factors directly from creep/fatigue tests. If the material softening saturates the proposed EPP strain limits method can be further simplified, providing a methodology based on temperature-dependent softening factors that could be implemented in an ASME code case allowing the use of the EPP strain limits method with Gr. 91. Finally, the report demonstrates the conservatism of the modified method when applied to inelastic simulation results and two bar experiments.« less
NASA Technical Reports Server (NTRS)
Murray, Harry E
1946-01-01
A vertical-tail model with stub fuselage was tested in combination with various simulated horizontal tails to determine the effect of horizontal-tail span and location on the aerodynamic characteristics of the vertical tail. Available theoretical data on end-plate effects were collected and presented in the form most suitable for design purposes. Reasonable agreement was obtained between the measured and theoretical end-plate effects of horizontal tails on vertical tails, and the data indicated that the end-plate effect was determined more by the location of the horizontal tail than by the span of the horizontal tail. The horizontal tail gave most end-plate effect when located near either tip of the vertical tail and, when located near the base of the vertical tail, the end-plate effect was increased by moving the horizontal tail rearward.
Zhang, Yu; Tang, Yibo; Shen, Hongxing
2017-12-01
In order to reduce the incidence of adjacent segment disease (ASD), the current study was designed to establish Chinese finite element models of normal 3rd~7th cervical vertebrae (C3-C7) and anterior cervical corpectomy and fusion (ACCF) with internal fixation , and analyze the influence of screw sagittal angle (SSA) on stress on endplate of adjacent cervical segments. Mimics 8.1 and Abaqus/CAE 6.10 softwares were adopted to establish finite element models. For C4 superior endplate and C6 inferior endplate, their anterior areas had the maximum stress in anteflexion position, and their posterior areas had the maximum stress in posterior extension position. As SSA increased, the stress reduced. With an increase of 10° in SSA, the stress on anterior areas of C4 superior endplate and C6 inferior endplate reduced by 12.67% and 7.99% in anteflexion position, respectively. With an increase of 10° in SSA, the stress on posterior areas of C4 superior endplate and C6 inferior endplate reduced by 9.68% and 10.22% in posterior extension position, respectively. The current study established Chinese finite element models of normal C3-C7 and ACCF with internal fixation , and demonstrated that as SSA increased, the stress on endplate of adjacent cervical segments decreased. In clinical surgery, increased SSA is able to play important role in protecting the adjacent cervical segments and reducing the incidence of ASD.
Preliminary test results in support of integrated EPP and SMT design methods development
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Yanli; Jetter, Robert I.; Sham, T. -L.
2016-02-09
The proposed integrated Elastic Perfectly-Plastic (EPP) and Simplified Model Test (SMT) methodology consists of incorporating a SMT data-based approach for creep-fatigue damage evaluation into the EPP methodology to avoid using the creep-fatigue interaction diagram (the D diagram) and to minimize over-conservatism while properly accounting for localized defects and stress risers. To support the implementation of the proposed code rules and to verify their applicability, a series of thermomechanical tests have been initiated. One test concept, the Simplified Model Test (SMT), takes into account the stress and strain redistribution in real structures by including representative follow-up characteristics in the test specimen.more » The second test concept is the two-bar thermal ratcheting tests with cyclic loading at high temperatures using specimens representing key features of potential component designs. This report summaries the previous SMT results on Alloy 617, SS316H and SS304H and presents the recent development on SMT approach on Alloy 617. These SMT specimen data are also representative of component loading conditions and have been used as part of the verification of the proposed integrated EPP and SMT design methods development. The previous two-bar thermal ratcheting test results on Alloy 617 and SS316H are also summarized and the new results from two bar thermal ratcheting tests on SS316H at a lower temperature range are reported.« less
Significance of Vertebral Endplate Failure in Symptomatic Lumbar Disc Herniation.
Sahoo, Madan Mohan; Mahapatra, Sudhir Kumar; Kaur, Sheetal; Sarangi, Jitendra; Mohapatra, Manoranjan
2017-05-01
Prospective cohort study. Endplate lesions though have been implicated in the genesis of lumbar disc herniation (LDH), very little is known regarding their clinical course. Thus, the present study is aimed to investigate the incidence and types of endplate failure (EPF) in LDH and its correlation with the clinical symptoms and prognosis. Clinical and magnetic resonance imaging (MRI) features of 66 patients with isolated single level LDH were studied. Three-dimensional fast spoiled gradient (3D FSPGR) MRI and computed tomography scans were used to identify the bony and cartilaginous EPF. Twenty-five patients were operated on and 41 patients were treated conservatively. Changes in the pain score, function and neurology were noted at 3, 6, 12, 24, and 36 weeks. Endplate lesions were observed in 64 patients (96.9%), including bony endplate failure (bony failure) in 47 patients (71.2%) and isolated cartilaginous endplate lesions in 17 patients (25.7%). Bony failure group had similar pain and functional scores but more severe neurological deficit at the initial evaluation. Clinical parameters improved in all groups, but the recovery was lesser in conservatively treated bony failure patients. Endplate lesions are commonly associated with symptomatic LDH. Presence of bony failure can increase neurological deficit and reduce the chance of recovery with conservative management. The 3D FSPGR sequence of MRI can be successfully used for detection of the endplate lesions in the herniated disc.
Influence of tip end-plate on noise of small axial fan
NASA Astrophysics Data System (ADS)
Mao, Hongya; Wang, Yanping; Lin, Peifeng; Jin, Yingzi; Setoguchi, Toshiaki; Kim, Heuy Dong
2017-02-01
In this work, tip end-plate is used to improve the noise performance of small axial fans. Both numerical simulations and experimental methods were adopted to study the fluid flow and noise level of axial fans. Four modified models and the prototype are simulated. Influences of tip end-plate on static characteristics, internal flow field and noise of small axial fans are analyzed. The results show that on basis of the prototype, the model with the tip end-plate of 2 mm width and changed length achieved best noise performance. The overall sound pressure level of the model with the tip end-plate of 2 mm width and changed length is 2.4 dB less than that of the prototype at the monitoring point in specified far field. It is found that the mechanism of noise reduction is due to the decrease of vorticity variation on the surface of blades caused by the tip end-plate. Compared with the prototype, the static pressure of the model with the tip end-plate of 2 mm width and changed length at design flow rate decreases by 2 Pa and the efficiency decreases by 0.8%. It is concluded that the method of adding tip end-plate to impeller blades has a positive influence on reducing noise, but it may diminish the static characteristics of small axial fan to some extent.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hollinger, Greg L.
Background: The current rules in the nuclear section of the ASME Boiler and Pressure Vessel (B&PV) Code , Section III, Subsection NH for the evaluation of strain limits and creep-fatigue damage using simplified methods based on elastic analysis have been deemed inappropriate for Alloy 617 at temperatures above 1200F (650C)1. To address this issue, proposed code rules have been developed which are based on the use of elastic-perfectly plastic (E-PP) analysis methods and which are expected to be applicable to very high temperatures. The proposed rules for strain limits and creep-fatigue evaluation were initially documented in the technical literature 2,more » 3, and have been recently revised to incorporate comments and simplify their application. The revised code cases have been developed. Task Objectives: The goal of the Sample Problem task is to exercise these code cases through example problems to demonstrate their feasibility and, also, to identify potential corrections and improvements should problems be encountered. This will provide input to the development of technical background documents for consideration by the applicable B&PV committees considering these code cases for approval. This task has been performed by Hollinger and Pease of Becht Engineering Co., Inc., Nuclear Services Division and a report detailing the results of the E-PP analyses conducted on example problems per the procedures of the E-PP strain limits and creep-fatigue draft code cases is enclosed as Enclosure 1. Conclusions: The feasibility of the application of the E-PP code cases has been demonstrated through example problems that consist of realistic geometry (a nozzle attached to a semi-hemispheric shell with a circumferential weld) and load (pressure; pipe reaction load applied at the end of the nozzle, including axial and shear forces, bending and torsional moments; through-wall transient temperature gradient) and design and operating conditions (Levels A, B and C).« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jetter, R. I.; Messner, M. C.; Sham, T. -L.
The goal of the proposed integrated Elastic Perfectly-Plastic (EPP) and Simplified Model Test (SMT) methodology is to incorporate an SMT data based approach for creep-fatigue damage evaluation into the EPP methodology to avoid the separate evaluation of creep and fatigue damage and eliminate the requirement for stress classification in current methods; thus greatly simplifying evaluation of elevated temperature cyclic service. This methodology should minimize over-conservatism while properly accounting for localized defects and stress risers. To support the implementation of the proposed methodology and to verify the applicability of the code rules, analytical studies and evaluation of thermomechanical test results continuedmore » in FY17. This report presents the results of those studies. An EPP strain limits methodology assessment was based on recent two-bar thermal ratcheting test results on 316H stainless steel in the temperature range of 405 to 7050C. Strain range predictions from the EPP evaluation of the two-bar tests were also evaluated and compared with the experimental results. The role of sustained primary loading on cyclic life was assessed using the results of pressurized SMT data from tests on Alloy 617 at 9500C. A viscoplastic material model was used in an analytic simulation of two-bar tests to compare with EPP strain limits assessments using isochronous stress strain curves that are consistent with the viscoplastic material model. A finite element model of a prior 304H stainless steel Oak Ridge National Laboratory (ORNL) nozzle-to-sphere test was developed and used for an EPP strain limits and creep-fatigue code case damage evaluations. A theoretical treatment of a recurring issue with convergence criteria for plastic shakedown illustrated the role of computer machine precision in EPP calculations.« less
Significance of Vertebral Endplate Failure in Symptomatic Lumbar Disc Herniation
Sahoo, Madan Mohan; Kaur, Sheetal; Sarangi, Jitendra; Mohapatra, Manoranjan
2017-01-01
Study Design: Prospective cohort study. Objective: Endplate lesions though have been implicated in the genesis of lumbar disc herniation (LDH), very little is known regarding their clinical course. Thus, the present study is aimed to investigate the incidence and types of endplate failure (EPF) in LDH and its correlation with the clinical symptoms and prognosis. Methods: Clinical and magnetic resonance imaging (MRI) features of 66 patients with isolated single level LDH were studied. Three-dimensional fast spoiled gradient (3D FSPGR) MRI and computed tomography scans were used to identify the bony and cartilaginous EPF. Twenty-five patients were operated on and 41 patients were treated conservatively. Changes in the pain score, function and neurology were noted at 3, 6, 12, 24, and 36 weeks. Results: Endplate lesions were observed in 64 patients (96.9%), including bony endplate failure (bony failure) in 47 patients (71.2%) and isolated cartilaginous endplate lesions in 17 patients (25.7%). Bony failure group had similar pain and functional scores but more severe neurological deficit at the initial evaluation. Clinical parameters improved in all groups, but the recovery was lesser in conservatively treated bony failure patients. Conclusion: Endplate lesions are commonly associated with symptomatic LDH. Presence of bony failure can increase neurological deficit and reduce the chance of recovery with conservative management. The 3D FSPGR sequence of MRI can be successfully used for detection of the endplate lesions in the herniated disc. PMID:28660105
Evaluation of the expert patient program in a Chinese population with permanent colostomy.
Cheng, Fang; Xu, Qin; Dai, Xiao-dong; Yang, Lin-li
2012-01-01
A colostomy can negatively impact patients' quality of life. Recent research findings suggest that self-efficacy and psychosocial adjustment are positively associated with quality of life, but there are few research reports about the self-efficacy and psychosocial adjustment of patients with a permanent colostomy. The objective of the study was to evaluate the effect of a 3-week Expert Patient Program (EPP) on colostomy knowledge, stoma care self-efficacy, self-management, and psychosocial adjustment in Chinese patients who had a permanent colostomy. Eleven patients with permanent colostomy volunteered to be trained to be expert patients. Eighty-one patients with permanent colostomy were recruited and participated in the 3-week EPP courses. Questionnaires with items about knowledge on colostomy, stoma care self efficacy, self-management, and psychosocial adjustment were administered before and at 4 weeks following the EPP courses. Each EPP participant also completed a verbal interview at the end of the program. The EPP participants demonstrated statistically significant improvement (P < .01) in knowledge, self-efficacy, self-management, and psychosocial adjustment to colostomy (mean [SD]: 51.89 [11.45] vs 89.22 [19.90], 71.56 [5.93] vs 85.61 [14.32], 125.44 [19.27] vs 140.78 [15.34], 47.59 [9.64] vs 53.37 [10.68], respectively). Most participants gave positive ratings to the EPP. This study showed that the EPP was applied effectively in patients with permanent colostomy. This study highlights the importance of psychosocial support for patients with permanent colostomy. It offers a model of self-help practice in colostomy patients, supported by community that can benefit more patients with permanent colostomy.
Octanol reduces end-plate channel lifetime
Gage, Peter W.; McBurney, Robert N.; Van Helden, Dirk
1978-01-01
1. Post-synaptic effects of n-octanol at concentrations of 0·1-1 mM were examined in toad sartorius muscles by use of extracellular and voltage-clamp techniques. 2. Octanol depressed the amplitude and duration of miniature end-plate currents and hence depressed neuromuscular transmission. 3. The decay of miniature end-plate currents remained exponential in octanol solutions even when the time constant of decay (τD) was decreased by 80-90%. 4. The lifetime of end-plate channels, obtained by analysis of acetylcholine noise, was also decreased by octanol. The average lifetime measured from noise spectra agreed reasonably well with the time constant of decay of miniature end-plate currents, both in control solution and in octanol solutions. 5. Octanol caused a reduction in the conductance of end-plate channels. Single channel conductance was on average about 25 pS in control solution and 20 pS in octanol. 6. In most cells the normal voltage sensitivity of the decay of miniature end-plate currents was retained in octanol solutions. The lifetime of end-plate channels measured from acetylcholine noise also remained voltage-sensitive in octanol solutions. In some experiments in which channel lifetime was exceptionally reduced the voltage sensitivity was less than normal. 7. In octanol solutions, τD was still very sensitive to temperature changes in most cells although in some the temperature sensitivity of τD was clearly reduced. Changes in τD with temperature could generally be fitted by the Arrhenius equation suggesting that a single step reaction controlled the decay of currents both in control and in octanol solutions. In some cells in which τD became less than 0·3 ms, the relationship between τD and temperature became inconsistent with the Arrhenius equation. 8. As the decay of end-plate currents in octanol solutions remains exponential, and the voltage and temperature sensitivity can be unchanged even when τD is significantly reduced, it seems likely that octanol decreases τD by increasing the rate of the reaction which normally controls the lifetime of end-plate channels. PMID:203674
Post-recurrence chemotherapy for mesothelioma patients undergoing extrapleural pneumonectomy.
Takuwa, Teruhisa; Hashimoto, Masaki; Matsumoto, Seiji; Kondo, Nobuyuki; Kuribayash, Kozo; Nakano, Takashi; Hasegawa, Seiki
2017-10-01
Additional chemotherapy is often not feasible in patients with recurrent malignant pleural mesothelioma (MPM) undergoing extrapleural pneumonectomy (EPP), due to deteriorated cardiopulmonary reserve. We thus examined the feasibility and efficacy of additional chemotherapy in patients with recurrent MPM after EPP. A retrospective review was conducted of 59 consecutive patients who underwent bi-/tri-modal treatment with induction chemotherapy, EPP, and radiation therapy from July 2004 to August 2013 at Hyogo College of Medicine (Nishinomiya, Japan). Of 59 patients, 39 (male/female = 31/8, right/left = 15/24, pathological stage I/II/III/IV = 1/7/23/3, bi-/tri-modality = 27/12) relapsed at a median age of 62 (range 37-71) years. The median time to recurrence after EPP was 11.6 months. Of the 39 relapsed patients, 12 received best supportive care alone, six started but discontinued chemotherapy, and the remaining 21 (53%) completed more than three cycles of intravenous chemotherapy. The median survival time after EPP was significantly longer in 21 patients who received additional chemotherapy than in 18 patients who did not (39.2 vs. 12.2 months, P = 0.009). Additional systemic chemotherapy was successfully administered in more than 50% of relapsed patients after bi-/tri-modal treatment, which included EPP, and resulted in a longer survival in comparison with best supportive care alone.
Surface modification by electrolytic plasma processing for high Nb-TiAl alloys
NASA Astrophysics Data System (ADS)
Gui, Wanyuan; Hao, Guojian; Liang, Yongfeng; Li, Feng; Liu, Xiao; Lin, Junpin
2016-12-01
Metal surface modification by electrolytic plasma processing (EPP) is an innovative treatment widely commonly applied to material processing and pretreatment process of coating and galvanization. EPP involves complex processes and a great deal of parameters, such as preset voltage, current, solution temperature and processing time. Several characterization methods are presented in this paper for evaluating the micro-structure surfaces of Ti45Al8Nb alloys: SEM, EDS, XRD and 3D topography. The results showed that the oxide scale and other contaminants on the surface of Ti45Al8Nb alloys can be effectively removed via EPP. The typical micro-crater structure of the surface of Ti45Al8Nb alloys were observed by 3D topography after EPP to find that the mean diameter of the surface structure and roughness value can be effectively controlled by altering the processing parameters. The mechanical properties of the surface according to nanomechanical probe testing exhibited slight decrease in microhardness and elastic modulus after EPP, but a dramatic increase in surface roughness, which is beneficial for further processing or coating.
NASA Astrophysics Data System (ADS)
Meraner, Katharina; Schmidt, Hauke
2018-01-01
Energetic particles enter the polar atmosphere and enhance the production of nitrogen oxides and hydrogen oxides in the winter stratosphere and mesosphere. Both components are powerful ozone destroyers. Recently, it has been inferred from observations that the direct effect of energetic particle precipitation (EPP) causes significant long-term mesospheric ozone variability. Satellites observe a decrease in mesospheric ozone up to 34 % between EPP maximum and EPP minimum. Stratospheric ozone decreases due to the indirect effect of EPP by about 10-15 % observed by satellite instruments. Here, we analyze the climate impact of winter boreal idealized polar mesospheric and polar stratospheric ozone losses as caused by EPP in the coupled Max Planck Institute Earth System Model (MPI-ESM). Using radiative transfer modeling, we find that the radiative forcing of mesospheric ozone loss during polar night is small. Hence, climate effects of mesospheric ozone loss due to energetic particles seem unlikely. Stratospheric ozone loss due to energetic particles warms the winter polar stratosphere and subsequently weakens the polar vortex. However, those changes are small, and few statistically significant changes in surface climate are found.
Zhang, Fan; Xu, Hao-Cheng; Yin, Bo; Xia, Xin-Lei; Ma, Xiao-Sheng; Wang, Hong-Li; Yin, Jun; Shao, Ming-Hao; Lyu, Fei-Zhou; Jiang, Jian-Yuan
2016-08-01
To evaluate the biomechanical characteristics of endplate-conformed cervical cages by finite element method (FEM) analysis and cadaver study. Twelve specimens (C2 -C7 ) and a finite element model (C3 -C7 ) were subjected to biomechanical evaluations. In the cadaver study, specimens were randomly assigned to intact (I), endplate-conformed (C) and non-conformed (N) groups with C4-5 discs as the treated segments. The morphologies of the endplate-conformed cages were individualized according to CT images of group C and the cages fabricated with a 3-D printer. The non-conformed cages were wedge-shaped and similar to commercially available grafts. Axial pre-compression loads of 73.6 N and moment of 1.8 Nm were used to simulate flexion (FLE), extension (EXT), lateral bending (LB) and axial rotation (AR). Range of motion (ROM) at C4-5 of each specimen was recorded and film sensors fixed between the cages and C5 superior endplates were used to detect interface stress. A finite element model was built based on the CT data of a healthy male volunteer. The morphologies of the endplate-conformed and wedge-shaped, non-conformed cervical cages were both simulated by a reverse engineering technique and implanted at the segment of C4-5 in the finite element model for biomechanical evaluation. Force loading and grouping were similar to those applied in the cadaver study. ROM of C4-5 in group I were recorded to validate the finite element model. Additionally, maximum cage-endplate interface stresses, stress distribution contours on adjoining endplates, intra-disc stresses and facet loadings at adjacent segments were measured and compared between groups. In the cadaver study, Group C showed a much lower interface stress in all directions of motion (all P < 0.05) and the ROM of C4-5 was smaller in FLE-EXT (P = 0.001) but larger in AR (P = 0.017). FEM analysis produced similar results: the model implanted with an endplate-conformed cage presented a lower interface stress with a more uniform stress distribution than that implanted with a non-conformed cage. Additionally, intra-disc stress and facet loading at the adjacent segments were obviously increased in both groups C and N, especially those at the supra-jacent segments. However, stress increase was milder in group C than in group N for all directions of motion. Endplate-conformed cages can decrease cage-endplate interface stress in all directions of motion and increase cervical stability in FLE-EXT. Additionally, adjacent segments are possibly protected because intra-disc stress and facet loading are smaller after endplate-conformed cage implantation. However, axial stability was reduced in group C, indicating that endplate-conformed cage should not be used alone and an anterior plate system is still important in anterior cervical discectomy and fusion. © 2016 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.
Erythropoietic Protoporphyria (EPP) or Protoporphyria
... protoporphyrin can differentiate X-linked protoporphyria from EPP. Molecular genetic testing can confirm a diagnosis of X-linked ... systematically and comprehensively plan an affected child’s treatment. Genetic ... expression and characterization of erythroid-specific 5-aminolevulinate ...
Fatehi, M; Rowan, E G; Harvey, A L
2002-01-01
The effects of Pa-1G, a phospholipase A(2) (PLA(2)) from the venom of the Australian king brown snake (Pseudechis australis) were determined on the release of acetylcholine, muscle resting membrane potential and motor nerve terminal action potential at mouse neuromuscular junction. Intracellular recording from endplate regions of mouse triangularis sterni nerve-muscle preparations revealed that Pa-1G (800 nM) significantly reduced the amplitude of endplate potentials within 10 min exposure. The quantal content of endplate potentials was decreased to 58+/-6% of control after 30 min exposure to 800 nM Pa-1G. The toxin also caused a partial depolarisation of mouse muscle fibres within 60 min exposure. Extracellular recording of action potentials at motor nerve terminals showed that Pa-1G reduced the waveforms associated with both sodium and potassium conductances. To investigate whether this was a direct or indirect effect of the toxin on these ionic currents, whole cell patch clamp experiments were performed using human neuroblastoma (SK-N-SH) cells and B82 mouse fibroblasts stably transfected with rKv1.2. Patch clamp recording experiments confirmed that potassium currents sensitive to alpha-dendrotoxin recorded from B82 cells and sodium currents in SK-N-SH cells were not affected by the toxin. Since neither facilitation of acetylcholine release at mouse neuromuscular junction nor depression of potassium currents in B82 cells has been observed, the apparent blockade of potassium currents at mouse motor nerve endings induced by the toxin is unlikely to be due to a selective block of potassium channels.
Rodrigues, Samantha A; Thambyah, Ashvin; Broom, Neil D
2015-03-01
The annulus-endplate anchorage system performs a critical role in the disc, creating a strong structural link between the compliant annulus and the rigid vertebrae. Endplate failure is thought to be associated with disc herniation, a recent study indicating that this failure mode occurs more frequently than annular rupture. The aim was to investigate the structural principles governing annulus-endplate anchorage and the basis of its strength and mechanisms of failure. Loading experiments were performed on ovine lumbar motion segments designed to induce annulus-endplate failure, followed by macro- to micro- to fibril-level structural analyses. The study was funded by a doctoral scholarship from our institution. Samples were loaded to failure in three modes: torsion using intact motion segments, in-plane tension of the anterior annulus-endplate along one of the oblique fiber angles, and axial tension of the anterior annulus-endplate. The anterior region was chosen for its ease of access. Decalcification was used to investigate the mechanical influence of the mineralized component. Structural analysis was conducted on both the intact and failed samples using differential interference contrast optical microscopy and scanning electron microscopy. Two main modes of anchorage failure were observed--failure at the tidemark or at the cement line. Samples subjected to axial tension contained more tidemark failures compared with those subjected to torsion and in-plane tension. Samples decalcified before testing frequently contained damage at the cement line, this being more extensive than in fresh samples. Analysis of the intact samples at their anchorage sites revealed that annular subbundle fibrils penetrate beyond the cement line to a limited depth and appear to merge with those in the vertebral and cartilaginous endplates. Annulus-endplate anchorage is more vulnerable to failure in axial tension compared with both torsion and in-plane tension and is probably due to acute fiber bending at the soft-hard interface of the tidemark. This finding is consistent with evidence showing that flexion, which induces a similar pattern of axial tension, increases the risk of herniation involving endplate failure. The study also highlights the important strengthening role of calcification at this junction and provides new evidence of a fibril-based form of structural integration across the cement line. Copyright © 2015 Elsevier Inc. All rights reserved.
Lavery, Katherine A; O'Neill, Brenda; Parker, Michael; Elborn, J Stuart; Bradley, Judy M
2011-08-01
To investigate the efficacy of a disease-specific Expert Patient Programme (EPP) compared with usual care in patients with bronchiectasis. Proof-of-concept randomized controlled trial. Regional respiratory center. Adult patients (N=64; age, >18y) with a primary diagnosis of bronchiectasis based on a respiratory physician's assessment including a computed tomographic scan. Patients were randomly assigned to an intervention (usual care plus EPP; n=32) or control group (usual care only; n=32). The primary outcome measure was the Chronic Disease Self-efficacy Scale (CDSS). Other outcome measures included the Revised Illness Perception Questionnaire (IPQ-R), the St Georges Respiratory Questionnaire, and standard EPP questionnaires. Data were collected at baseline, postintervention, and 3 and 6 months postintervention. This disease-specific EPP for patients with bronchiectasis significantly improved self-efficacy in 6 of 10 subscales (CDSS subscales: exercise regularly [P=.02]; get information about disease [P=.03]; obtain help from community, family, and friends [P=.06]; communicate with physician [P=.85]; manage disease in general [P=.05]; do chores [P=.04]; social/recreational activities [P=.03]; manage symptoms [P<.01]; manage shortness of breath [P=.08]; control/manage depression [P=.01]) compared with usual care. There was no improvement on IPQ-R score. Patients who received the intervention reported more symptoms and decreased quality of life between 3 and 6 months postintervention and an increase in some components of self reported health care use. Patients receiving the disease-specific EPP indicated they were satisfied with the intervention and learned new self-management techniques. There were no significant differences in lung function over time. This original study indicates that a disease-specific EPP results in short-term improvements in self-efficacy. Based on these positive preliminary findings, a larger adequately powered study is justified to investigate the efficacy of a disease-specific EPP in patients with bronchiectasis. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
Maietti, Annalisa; Tedeschi, Paola; Stagno, Caterina; Bordiga, Matteo; Travaglia, Fabiano; Locatelli, Monica; Arlorio, Marco; Brandolini, Vincenzo
2012-06-01
Two morphologically different cultivars of Italian melons (Baggio and Giusto) were characterized considering samples harvested in different times, at the beginning (BPP) and at the end of the physiological plant production period (EPP). Proximate composition, protein, minerals, pH, phenolic content, antioxidant capacity, ascorbic acid, carotenoids, condensed tannins, and flavonoids were measured, showing a significant decrease in EPP samples (phenolics, antioxidant capacity, condensed tannins, and flavonoids); ascorbic acid decreased in Giusto cv, carotenoids in Baggio cv. Mineral content increased in either the cultivars (EPP samples). Year-to-year difference was significantly highlighted; the plant growing cycle significantly affected the chemotype. Despite these effects, the Principal Component Analysis (PCA) permitted the discrimination of Baggio from Giusto cv, and the discrimination of BPP from EPP samples as well. © 2012 Institute of Food Technologists®
Maselli, Ricardo A; Arredondo, Juan; Vázquez, Jessica; Chong, Jessica X; Bamshad, Michael J; Nickerson, Deborah A; Lara, Marian; Ng, Fiona; Lo, Victoria L; Pytel, Peter; McDonald, Craig M
2017-08-01
Defects in genes encoding the isoforms of the laminin alpha subunit have been linked to various phenotypic manifestations, including brain malformations, muscular dystrophy, ocular defects, cardiomyopathy, and skin abnormalities. We report here a severe defect of neuromuscular transmission in a consanguineous patient with a homozygous variant in the laminin alpha-5 subunit gene (LAMA5). The variant c.8046C>T (p.Arg2659Trp) is rare and has a predicted deleterious effect. The affected individual, who also carries a rare homozygous sequence variant in LAMA1, had muscle weakness, myopia, and facial tics. Magnetic resonance imaging of brain showed mild volume loss and periventricular T2 prolongation. Repetitive nerve stimulation revealed 50% decrement of compound muscle action potential amplitudes and 250% facilitation immediately after exercise, Endplate studies identified a profound reduction of the endplate potential quantal content and endplates with normal postsynaptic folding that were denuded or partially occupied by small nerve terminals. Expression studies revealed that p.Arg2659Trp caused decreased binding of laminin alpha-5 to SV2A and impaired laminin-521 cell-adhesion and cell projection support in primary neuronal cultures. In summary, this report describing severe neuromuscular transmission failure in a patient with a LAMA5 mutation expands the list of phenotypes associated with defects in genes encoding alpha-laminins. © 2017 Wiley Periodicals, Inc.
Protection of human muscle acetylcholinesterase from soman by pyridostigmine bromide.
Maselli, Ricardo A; Henderson, John D; Ng, Jarae; Follette, David; Graves, Gregory; Wilson, Barry W
2011-04-01
Pretreatment with pyridostigmine bromide (PB) of human intercostal muscle fibers exposed to the irreversible acetylcholinesterase (AChE) inhibitor soman was investigated. Muscles were pretreated with 3 × 10(-6) M PB or saline for 20 minutes, then exposed to 10(-7) M soman for 10 minutes. AChE of muscles treated with soman alone was inhibited >95%. In contrast, PB pretreatment of soman-exposed bundles protected 20% of AChE activity. AChE of bundles exposed to PB alone recovered after 4 hours, but bundles exposed to both PB and soman did not. Soman-induced reduction of resting membrane potentials and increment of amplitudes and decay times of miniature endplate potentials (MEPPs) were partially corrected by PB pretreatment. In vitro pretreatment of human muscles with PB protected up to 20% of muscle AChE and ameliorated some deleterious effects on endplate physiology induced by soman. Copyright © 2011 Wiley Periodicals, Inc.
Garcia, Neus; Santafé, Manel M; Tomàs, Marta; Lanuza, Maria A; Besalduch, Nuria; Tomàs, Josep
2010-04-05
Confocal immunohistochemistry shows that neurotrophin-3 (NT-3) and its receptor tropomyosin-related tyrosin kinase C (trkC) are present in both neonatal (P6) and adult (P45) mouse motor nerve terminals in neuromuscular junctions (NMJ) colocalized with several synaptic proteins. NT-3 incubation (1-3h, in the range 10-200ng/ml) does not change the size of the evoked and spontaneous endplate potentials at P45. However, NT-3 (1h, 100ng/ml) strongly potentiates evoked ACh release from the weak (70%) and the strong (50%) axonal inputs on dually innervated postnatal endplates (P6) but not in the most developed postnatal singly innervated synapses at P6. The present results indicate that NT-3 has a role in the developmental mechanism that eliminates redundant synapses though it cannot modulate synaptic transmission locally as the NMJ matures.
Correlates of genetic monogamy in socially monogamous mammals: insights from Azara's owl monkeys
Huck, Maren; Fernandez-Duque, Eduardo; Babb, Paul; Schurr, Theodore
2014-01-01
Understanding the evolution of mating systems, a central topic in evolutionary biology for more than 50 years, requires examining the genetic consequences of mating and the relationships between social systems and mating systems. Among pair-living mammals, where genetic monogamy is extremely rare, the extent of extra-group paternity rates has been associated with male participation in infant care, strength of the pair bond and length of the breeding season. This study evaluated the relationship between two of those factors and the genetic mating system of socially monogamous mammals, testing predictions that male care and strength of pair bond would be negatively correlated with rates of extra-pair paternity (EPP). Autosomal microsatellite analyses provide evidence for genetic monogamy in a pair-living primate with bi-parental care, the Azara's owl monkey (Aotus azarae). A phylogenetically corrected generalized least square analysis was used to relate male care and strength of the pair bond to their genetic mating system (i.e. proportions of EPP) in 15 socially monogamous mammalian species. The intensity of male care was correlated with EPP rates in mammals, while strength of pair bond failed to reach statistical significance. Our analyses show that, once social monogamy has evolved, paternal care, and potentially also close bonds, may facilitate the evolution of genetic monogamy. PMID:24648230
Correlates of genetic monogamy in socially monogamous mammals: insights from Azara's owl monkeys.
Huck, Maren; Fernandez-Duque, Eduardo; Babb, Paul; Schurr, Theodore
2014-05-07
Understanding the evolution of mating systems, a central topic in evolutionary biology for more than 50 years, requires examining the genetic consequences of mating and the relationships between social systems and mating systems. Among pair-living mammals, where genetic monogamy is extremely rare, the extent of extra-group paternity rates has been associated with male participation in infant care, strength of the pair bond and length of the breeding season. This study evaluated the relationship between two of those factors and the genetic mating system of socially monogamous mammals, testing predictions that male care and strength of pair bond would be negatively correlated with rates of extra-pair paternity (EPP). Autosomal microsatellite analyses provide evidence for genetic monogamy in a pair-living primate with bi-parental care, the Azara's owl monkey (Aotus azarae). A phylogenetically corrected generalized least square analysis was used to relate male care and strength of the pair bond to their genetic mating system (i.e. proportions of EPP) in 15 socially monogamous mammalian species. The intensity of male care was correlated with EPP rates in mammals, while strength of pair bond failed to reach statistical significance. Our analyses show that, once social monogamy has evolved, paternal care, and potentially also close bonds, may facilitate the evolution of genetic monogamy.
Lightweight bipolar storage battery
NASA Technical Reports Server (NTRS)
Rowlette, John J. (Inventor)
1992-01-01
An apparatus [10] is disclosed for a lightweight bipolar battery of the end-plate cell stack design. Current flow through a bipolar cell stack [12] is collected by a pair of copper end-plates [16a,16b] and transferred edgewise out of the battery by a pair of lightweight, low resistance copper terminals [28a,28b]. The copper terminals parallel the surface of a corresponding copper end-plate [16a,16b] to maximize battery throughput. The bipolar cell stack [12], copper end-plates [16a,16b] and copper terminals [28a,28b] are rigidly sandwiched between a pair of nonconductive rigid end-plates [20] having a lightweight fiber honeycomb core which eliminates distortion of individual plates within the bipolar cell stack due to internal pressures. Insulating foam [30] is injected into the fiber honeycomb core to reduce heat transfer into and out of the bipolar cell stack and to maintain uniform cell performance. A sealed battery enclosure [ 22] exposes a pair of terminal ends [26a,26b] for connection with an external circuit.
Geometry of the intervertebral volume and vertebral endplates of the human spine.
van der Houwen, E B; Baron, P; Veldhuizen, A G; Burgerhof, J G M; van Ooijen, P M A; Verkerke, G J
2010-01-01
Replacement of a degenerated vertebral disc with an artificial intervertebral disc (AID) is currently possible, but poses problems, mainly in the force distribution through the vertebral column. Data on the intervertebral disc space geometry will provide a better fit of the prosthesis to the vertebrae, but current literature on vertebral disc geometry is very scarce or not suitable. In this study, existing CT-scans of 77 patients were analyzed to measure the intervertebral disc and vertebral endplate geometry of the lumbar spine. Ten adjacent points on both sides of the vertebrae (S1-superior to T12-inferior) and sagittal and transverse diameters were measured to describe the shape of the caudal and cranial vertebral planes of the vertebrae. It was found that the largest endplate depth is located in the middle or posterior regions of the vertebra, that there is a linear relationship between all inferior endplate depths and the endplate location (p < 0.0001) within the spinal column, and that the superior endplate depth increases with age by about 0.01 mm per year (p < 0.02). The wedge angle increases from T12-L1 to L5-S1. The results allow for improvement of the fit of intervertebral disc-prostheses to the vertebrae and optimized force transmission through the vertebral column.
Nekkanty, Srikant; Yerramshetty, Janardhan; Kim, Do-Gyoon; Zauel, Roger; Johnson, Evan; Cody, Dianna D.; Yeni, Yener N.
2013-01-01
Stress magnitude and variability as estimated from large scale finite element (FE) analyses have been associated with compressive strength of human vertebral cancellous cores but these relationships have not been explored for whole vertebral bodies. In this study, the objectives were to investigate the relationship of FE-calculated stress distribution parameters with experimentally determined strength, stiffness, and displacement based ductility measures in human whole vertebral bodies, investigate the effect of endplate loading conditions on vertebral stiffness, strength, and ductility and test the hypothesis that endplate topography affects vertebral ductility and stress distributions. Eighteen vertebral bodies (T6-L3 levels; 4 female and 5 male cadavers, aged 40-98 years) were scanned using a flat panel CT system and followed with axial compression testing with Wood’s metal as filler material to maintain flat boundaries between load plates and specimens. FE models were constructed using reconstructed CT images and filler material was added digitally. Two different FE models with different filler material modulus simulating Wood’s metal and intervertebral disc (W-layer and D-layer models) were used. Element material modulus to cancellous bone was based on image gray value. Average, standard deviation, and coefficient of variation of von Mises stress in vertebral bone for W-layer and D-layer models and also the ratios of FE parameters from the two models (W/D) were calculated. Inferior and superior endplate surface topographical distribution parameters were calculated. Experimental stiffness, maximum load and work to fracture had the highest correlation with FE-calculated stiffness while experimental ductility measures had highest correlations with FE-calculated average von Mises stress and W-layer to D-layer stiffness ratio. Endplate topography of the vertebra was also associated with its structural ductility and the distribution parameter that best explained this association was kurtosis of inferior endplate topography. Our results indicate that endplate topography variations may provide insight into the mechanisms responsible for vertebral fractures. PMID:20633709
A fast one-chip event-preprocessor and sequencer for the Simbol-X Low Energy Detector
NASA Astrophysics Data System (ADS)
Schanz, T.; Tenzer, C.; Maier, D.; Kendziorra, E.; Santangelo, A.
2010-12-01
We present an FPGA-based digital camera electronics consisting of an Event-Preprocessor (EPP) for on-board data preprocessing and a related Sequencer (SEQ) to generate the necessary signals to control the readout of the detector. The device has been originally designed for the Simbol-X low energy detector (LED). The EPP operates on 64×64 pixel images and has a real-time processing capability of more than 8000 frames per second. The already working releases of the EPP and the SEQ are now combined into one Digital-Camera-Controller-Chip (D3C).
Morsch, Marco; Reddel, Stephen W; Ghazanfari, Nazanin; Toyka, Klaus V; Phillips, William D
2013-01-01
In myasthenia gravis, the neuromuscular junction is impaired by the antibody-mediated loss of postsynaptic acetylcholine receptors (AChRs). Muscle weakness can be improved upon treatment with pyridostigmine, a cholinesterase inhibitor, or with 3,4-diaminopyridine, which increases the release of ACh quanta. The clinical efficacy of pyridostigmine is in doubt for certain forms of myasthenia. Here we formally examined the effects of these compounds in the antibody-induced mouse model of anti-muscle-specific kinase (MuSK) myasthenia gravis. Mice received 14 daily injections of IgG from patients with anti-MuSK myasthenia gravis. This caused reductions in postsynaptic AChR densities and in endplate potential amplitudes. Systemic delivery of pyridostigmine at therapeutically relevant levels from days 7 to 14 exacerbated the anti-MuSK-induced structural alterations and functional impairment at motor endplates in the diaphragm muscle. No such effect of pyridostigmine was found in mice receiving control human IgG. Mice receiving smaller amounts of MuSK autoantibodies did not display overt weakness, but 9 days of pyridostigmine treatment precipitated generalised muscle weakness. In contrast, one week of treatment with 3,4-diaminopyridine enhanced neuromuscular transmission in the diaphragm muscle. Both pyridostigmine and 3,4-diaminopyridine increase ACh in the synaptic cleft yet only pyridostigmine potentiated the anti-MuSK-induced decline in endplate ACh receptor density. These results thus suggest that ongoing pyridostigmine treatment potentiates anti-MuSK-induced AChR loss by prolonging the activity of ACh in the synaptic cleft. PMID:23440963
Morsch, Marco; Reddel, Stephen W; Ghazanfari, Nazanin; Toyka, Klaus V; Phillips, William D
2013-05-15
In myasthenia gravis, the neuromuscular junction is impaired by the antibody-mediated loss of postsynaptic acetylcholine receptors (AChRs). Muscle weakness can be improved upon treatment with pyridostigmine, a cholinesterase inhibitor, or with 3,4-diaminopyridine, which increases the release of ACh quanta. The clinical efficacy of pyridostigmine is in doubt for certain forms of myasthenia. Here we formally examined the effects of these compounds in the antibody-induced mouse model of anti-muscle-specific kinase (MuSK) myasthenia gravis. Mice received 14 daily injections of IgG from patients with anti-MuSK myasthenia gravis. This caused reductions in postsynaptic AChR densities and in endplate potential amplitudes. Systemic delivery of pyridostigmine at therapeutically relevant levels from days 7 to 14 exacerbated the anti-MuSK-induced structural alterations and functional impairment at motor endplates in the diaphragm muscle. No such effect of pyridostigmine was found in mice receiving control human IgG. Mice receiving smaller amounts of MuSK autoantibodies did not display overt weakness, but 9 days of pyridostigmine treatment precipitated generalised muscle weakness. In contrast, one week of treatment with 3,4-diaminopyridine enhanced neuromuscular transmission in the diaphragm muscle. Both pyridostigmine and 3,4-diaminopyridine increase ACh in the synaptic cleft yet only pyridostigmine potentiated the anti-MuSK-induced decline in endplate ACh receptor density. These results thus suggest that ongoing pyridostigmine treatment potentiates anti-MuSK-induced AChR loss by prolonging the activity of ACh in the synaptic cleft.
The permeability of endplate channels to monovalent and divalent metal cations
1980-01-01
The relative permeability of endplate channels to monovalent and divalent metal ions was determined from reversal potentials. Thallium is the most permeant ion with a permeability ratio relative to Na+ of 2.5. The selectivity among alkali metals is weak with a sequence, Cs+ greater than Rb+ greater than K+ greater than Na+ greater than Li+, and permeability ratios of 1.4, 1.3, 1.1, 1.0, and 0.9. The selectivity among divalent ions is also weak, with a sequence for alkaline earths of Mg++ greater than Ca++ greater than Ba++ greater than Sr++. The transition metal ions Mn++, Co++, Ni++, Zn++, and Cd++ are also permeant. Permeability ratios for divalent ions decreased as the concentration of divalent ion was increased in a manner consistent with the negative surface potential theory of Lewis (1979 J. Physiol. (Lond.). 286: 417--445). With 20 mM XCl2 and 85.5 mM glucosamine.HCl in the external solution, the apparent permeability ratios for the alkaline earth cations (X++) are in the range 0.18--0.25. Alkali metal ions see the endplate channel as a water-filled, neutral pore without high-field-strength sites inside. Their permeability sequence is the same as their aqueous mobility sequence. Divalent ions, however, have a permeability sequence almost opposite from their mobility sequence and must experience some interaction with groups in the channel. In addition, the concentrations of monovalent and divalent ions are increased near the channel mouth by a weak negative surface potential. PMID:6247423
Kalina, Maria; Kalina-Faska, Barbara; Gruszczyńska, Katarzyna; Baron, Jan; Cisowska, Anita; Morawiec, Karolina; Biel-Lewandowska, Paulina; Małecka-Tendera, Ewa
2015-01-01
Structural defects of the hypothalamic-pituitary area in MRI are suggested as being a more accurate marker of growth hormone deficiency (GHD) than laboratory assays. To compare auxological characteristics in GHD children with normal pituitary (NP) function and with ectopic posterior pituitary (EPP), prior to therapy with recombinant human growth hormone (rhGH), extending the follow-up to two years following treatment. Eighty-six (86) GHD patients were divided into two groups depending on the pituitary MRI: the EPP (23 children, 3.2-16.8 years old) and the NP group (63 children, 3.3-14.8 years old). Height deficits in the population (hSD) and parents (hSD-mpSD) and the change of hSD and bone/chronological age ratio were assessed before and after 12 and 24 months of rhGH therapy. Height deficits before treatment were significantly greater in EPP compared to NP [median -4.07 (-7.06, -2.75) vs -3.15 (-4.9, -2.35) for hSD, and -3.65 (-7.06, -1.21) vs -1.83 (-4.31, -0.28) for hSD-mpSD; p<0.05]. Bone age was significantly delayed in the EPP group [0.62 (0.27, 0.92) vs 0.75 (0.21, 0.71); p<0.05]; differences remained significant during follow-up. After 12 months of rhGH therapy, EPP showed significantly greater catch-up growth compared to NP [ΔhSD=1.2 (0.42, 2.69) vs 0.74 (0.05, 1.48); p<0.05]. In the 2nd year, height velocity slowed down and was comparable in the two groups. At the conclusion of the study, hSD was similar in both groups, but hSD-mpSD was more deviated in EPP [-1.79 (-3.71, -1.21) vs -1.1 (0.98, -0.07); p<0.05]. The study showed relevant auxologic differences between EPP and NP children, as well as beneficial effects of rhGH therapy in both groups.
ERIC Educational Resources Information Center
Dixon, Paul W.; Ahern, Elsie H.
1973-01-01
EPPS scores from 167 high school seniors (Study 1, S1), 137 introductory psychology students (S2), and students from an innovative college program (S3) were compared using analysis of variance, image analysis, and factor pattern comparison. (Editor)
Cartilage of the Intervertebral Disc Eng-Plate, A Histological, Histochemical, Fine Structure Study.
1982-08-01
degeneration (Nachemson et al., 1970). These and related studies consider the end-plates to be composed of hyaline cartilage and thus homologues of articular...results of this study in rhesus indicate, that while present, the cartilage of the end-plate is quite different in structure and presumably...HZSTOLO6ZCAL,-ETCfU) I AUG 82 N 5 NUSSBAUM IUNCLASSIFDATRL8R-1222NL.rnximommmB~iIEND2 AFAMRL-TR-81 - 122 " CARTILAGE OF THE INTERVERTEBRAL DISC END-PLATE A
Xu, Hong-Guang; Ma, Ming-Ming; Zheng, Quan; Shen, Xiang; Wang, Hong; Zhang, Shu-Feng; Xu, Jia-Jia; Wang, Chuan-Dong; Zhang, Xiao-Ling
2016-08-15
The changes of endplate chondrocytes induced by intermittent cyclic mechanical tension (ICMT) were observed by realtime reverse transcription-polymerase chain reaction, immunofluorescence, and Western blot analysis. To investigate the role of RhoA/ROCK-1 signaling pathway and E-cadherin/P120-catenin complex in endplate chondrocytes degeneration induced by ICMT. ICMT can induce the endplate chondrocyte degeneration. However, the relationship between P120-catenin or RhoA/ROCK-1 signaling pathway and endplate chondrocytes degeneration induced by ICMT is not clear. ICMT (strain at 0.5 Hz sinusoidal curve at 8% elongation) was applied to rat endplate chondrocytes for 6 days, 16 hours a day. The cell viability and apoptosis were examined by the LIVE/DEAD assay and flow cytometry. Histological staining was used to examine the lumbar disc tissue morphology and extracellular matrix. To regulate RhoA/ROCK-1 signaling pathway and the expression of E-cadherin and P120-catenin, RhoA/ROCK-1 pathway-specific inhibitors, E-cadherin, and p120-catenin plasmid were applied. Coimmunoprecipitation was employed to examine the interaction between E-cadherin and P120-catenin, P120-catenin, and RhoA. The related gene expression and protein location was examined by realtime reverse transcription-polymerase chain reaction, Western blot, and immunofluorescence. There was no change of viability verified by LIVE/DEAD assay and flow cytometry after ICMT loading. ICMT loading led to RhoA/ROCK-1 signaling activation and the loss of the chondrogenic phenotype of endplate chondrocytes. Inhibition of RhoA/ROCK-1 signaling pathway significantly ameliorated the degeneration induced by ICMT. The expression of P120-catenin and E-cadherin were inhibited by ICMT. ICMT reduced the interaction between P120-catenin and E-cadherin. Furthermore, over-expression of P120-catenin and E-cadherin can suppress the expression of chondrogenic gene, over-expression of P120-catenin can suppress the RhoA/ROCK-1 signaling pathway, but over-expression of E-cadherin cannot do it. P120-catenin protects endplate chondrocytes from ICMT Induced degeneration by inhibiting the expression of RhoA/ROCK-1 signaling pathway. N/A.
EPP Monitor, Volume 8, Issues 1&2, Spring/Summer 2004
ERIC Educational Resources Information Center
Guerrier, Martine
2004-01-01
This issue of EPP Monitor contains the following articles: "Countdown for Justice," Five Quick and Inexpensive Ways to End Overcrowding," "Third Grade Retention -- Deja Vu All Over Again," High-Need African-American and Latino Students Doing Better in Suburban Districts," "An Emerging Consensus on Facts, not…
Finite Element Study of a Lumbar Intervertebral Disc Nucleus Replacement Device.
Coogan, Jessica S; Francis, W Loren; Eliason, Travis D; Bredbenner, Todd L; Stemper, Brian D; Yoganandan, Narayan; Pintar, Frank A; Nicolella, Daniel P
2016-01-01
Nucleus replacement technologies are a minimally invasive alternative to spinal fusion and total disc replacement that have the potential to reduce pain and restore motion for patients with degenerative disc disease. Finite element modeling can be used to determine the biomechanics associated with nucleus replacement technologies. The current study focuses on a new nucleus replacement device designed as a conforming silicone implant with an internal void. A validated finite element model of the human lumbar L3-L4 motion segment was developed and used to investigate the influence of the nucleus replacement device on spine biomechanics. In addition, the effect of device design changes on biomechanics was determined. A 3D, L3-L4 finite element model was constructed from medical imaging data. Models were created with the normal intact nucleus, the nucleus replacement device, and a solid silicone implant. Probabilistic analysis was performed on the normal model to provide quantitative validation metrics. Sensitivity analysis was performed on the silicone Shore A durometer of the device. Models were loaded under axial compression followed by flexion/extension, lateral bending, or axial rotation. Compressive displacement, endplate stresses, reaction moment, and annulus stresses were determined and compared between the different models. The novel nucleus replacement device resulted in similar compressive displacement, endplate stress, and annulus stress and slightly higher reaction moment compared with the normal nucleus. The solid implant resulted in decreased displacement, increased endplate stress, decreased annulus stress, and decreased reaction moment compared with the novel device. With increasing silicone durometer, compressive displacement decreased, endplate stress increased, reaction moment increased, and annulus stress decreased. Finite element analysis was used to show that the novel nucleus replacement device results in similar biomechanics compared with the normal intact nucleus.
Finite Element Study of a Lumbar Intervertebral Disc Nucleus Replacement Device
Coogan, Jessica S.; Francis, W. Loren; Eliason, Travis D.; Bredbenner, Todd L.; Stemper, Brian D.; Yoganandan, Narayan; Pintar, Frank A.; Nicolella, Daniel P.
2016-01-01
Nucleus replacement technologies are a minimally invasive alternative to spinal fusion and total disc replacement that have the potential to reduce pain and restore motion for patients with degenerative disc disease. Finite element modeling can be used to determine the biomechanics associated with nucleus replacement technologies. The current study focuses on a new nucleus replacement device designed as a conforming silicone implant with an internal void. A validated finite element model of the human lumbar L3–L4 motion segment was developed and used to investigate the influence of the nucleus replacement device on spine biomechanics. In addition, the effect of device design changes on biomechanics was determined. A 3D, L3–L4 finite element model was constructed from medical imaging data. Models were created with the normal intact nucleus, the nucleus replacement device, and a solid silicone implant. Probabilistic analysis was performed on the normal model to provide quantitative validation metrics. Sensitivity analysis was performed on the silicone Shore A durometer of the device. Models were loaded under axial compression followed by flexion/extension, lateral bending, or axial rotation. Compressive displacement, endplate stresses, reaction moment, and annulus stresses were determined and compared between the different models. The novel nucleus replacement device resulted in similar compressive displacement, endplate stress, and annulus stress and slightly higher reaction moment compared with the normal nucleus. The solid implant resulted in decreased displacement, increased endplate stress, decreased annulus stress, and decreased reaction moment compared with the novel device. With increasing silicone durometer, compressive displacement decreased, endplate stress increased, reaction moment increased, and annulus stress decreased. Finite element analysis was used to show that the novel nucleus replacement device results in similar biomechanics compared with the normal intact nucleus. PMID:27990418
Geerts, Cornelia J; Plomp, Jaap J; Koopmans, Bastijn; Loos, Maarten; van der Pijl, Elizabeth M; van der Valk, Martin A; Verhage, Matthijs; Groffen, Alexander J A
2015-07-01
Tomosyn-1 (STXBP5) is a soluble NSF attachment protein receptor complex-binding protein that inhibits vesicle fusion, but the role of tomosyn-2 (STXBP5L) in the mammalian nervous system is still unclear. Here we generated tomosyn-2 null (Tom2(KO/KO)) mice, which showed impaired motor performance. This was accompanied by synaptic changes at the neuromuscular junction, including enhanced spontaneous acetylcholine release frequency and faster depression of muscle motor endplate potentials during repetitive stimulation. The postsynaptic geometric arrangement and function of acetylcholine receptors were normal. We conclude that tomosyn-2 supports motor performance by regulation of transmitter release willingness to sustain synaptic strength during high-frequency transmission, which makes this gene a candidate for involvement in neuromuscular disorders.
Buffers more than buffering agent: introducing a new class of stabilizers for the protein BSA.
Gupta, Bhupender S; Taha, Mohamed; Lee, Ming-Jer
2015-01-14
In this study, we have analyzed the influence of four biological buffers on the thermal stability of bovine serum albumin (BSA) using dynamic light scattering (DLS). The investigated buffers include 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES), 4-(2-hydroxyethyl)-1-piperazine-propanesulfonic acid (EPPS), 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid sodium salt (HEPES-Na), and 4-morpholinepropanesulfonic acid sodium salt (MOPS-Na). These buffers behave as a potential stabilizer for the native structure of BSA against thermal denaturation. The stabilization tendency follows the order of MOPS-Na > HEPES-Na > HEPES ≫ EPPS. To obtain an insight into the role of hydration layers and peptide backbone in the stabilization of BSA by these buffers, we have also explored the phase transition of a thermoresponsive polymer, poly(N-isopropylacrylamide (PNIPAM)), a model compound for protein, in aqueous solutions of HEPES, EPPS, HEPES-Na, and MOPS-Na buffers at different concentrations. It was found that the lower critical solution temperatures (LCST) of PNIPAM in the aqueous buffer solutions substantially decrease with increase in buffer concentration. The mechanism of interactions between these buffers and protein BSA was probed by various techniques, including UV-visible, fluorescence, and FTIR. The results of this series of studies reveal that the interactions are mainly governed by the influence of the buffers on the hydration layers surrounding the protein. We have also explored the possible binding sites of BSA with these buffers using a molecular docking technique. Moreover, the activities of an industrially important enzyme α-chymotrypsin (α-CT) in 0.05 M, 0.5 M, and 1.0 M of HEPES, EPPS, HEPES-Na, and MOPS-Na buffer solutions were analyzed at pH = 8.0 and T = 25 °C. Interestingly, the activities of α-CT were found to be enhanced in the aqueous solutions of these investigated buffers. Based upon the Jones-Dole viscosity parameters, the kosmotropic or chaotropic behaviors of the investigated buffers at 25 °C have been examined.
The Dependency Axiom and the Relation between Agreement and Movement
ERIC Educational Resources Information Center
Linares Scarcerieau, Carlo Andrei
2012-01-01
Agreement and movement go hand in hand in a number of constructions across languages, and this correlation has played an important role in syntactic theory. The current standard approach to this "movement-agreement connection" is the Agree+EPP model, whose EPP component has often been questioned on conceptual grounds. The goal of this…
The Development of a Comprehensive Intervention Plan for Millsboro Middle School
ERIC Educational Resources Information Center
Hudson, LouAnn
2012-01-01
The focus of this Executive Position Paper (EPP) is school improvement through the development and implementation a comprehensive, research-based, intervention plan for Millsboro Middle School (MMS) in the Indian River School District (IRSD). Studies conducted for this EPP began with an informal investigation of MMS data that included the Delaware…
Report on FY17 testing in support of integrated EPP-SMT design methods development
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Yanli .; Jetter, Robert I.; Sham, T. -L.
The goal of the proposed integrated Elastic Perfectly-Plastic (EPP) and Simplified Model Test (SMT) methodology is to incorporate a SMT data-based approach for creep-fatigue damage evaluation into the EPP methodology to avoid the separate evaluation of creep and fatigue damage and eliminate the requirement for stress classification in current methods; thus greatly simplifying evaluation of elevated temperature cyclic service. The purpose of this methodology is to minimize over-conservatism while properly accounting for localized defects and stress risers. To support the implementation of the proposed methodology and to verify the applicability of the code rules, thermomechanical tests continued in FY17. Thismore » report presents the recent test results for Type 1 SMT specimens on Alloy 617 with long hold times, pressurization SMT on Alloy 617, and two-bar thermal ratcheting test results on SS316H at the temperature range of 405 °C to 705 °C. Preliminary EPP strain range analysis on the two-bar tests are critically evaluated and compared with the experimental results.« less
Wei, Xiang-Lan; Fang, Ru-Tang; Yang, Yong-Hua; Bi, Xue-Yuan; Ren, Guo-Xia; Luo, A-Li; Zhao, Ming; Zang, Wei-Jin
2015-10-27
Liver fibrosis is a feature in the majority of chronic liver diseases and oxidative stress is considered to be its main pathogenic mechanism. Antioxidants including vitamin E, are effective in preventing liver fibrogenesis. Several plant-drived antioxidants, such as silymarin, baicalin, beicalein, quercetin, apigenin, were shown to interfere with liver fibrogenesis. The antioxidans above are polyphenols, flavonoids or structurally related compounds which are the main chemical components of Pomegranate peels and seeds, and the antioxidant activity of Pomegranate peels and seeds have been verified. Here we investigated whether the extracts of pomegranate peels (EPP) and seeds (EPS) have preventive efficacy on liver fibrosis induced by carbon tetrachloride (CCl4) in rats and explored its possible mechanisms. The animal model was established by injection with 50 % CCl4 subcutaneously in male wistar rats twice a week for four weeks. Meanwhile, EPP and EPS were administered orally every day for 4 weeks, respectively. The protective effects of EPP and EPS on biochemical metabolic parameters, liver function, oxidative markers, activities of antioxidant enzymes and liver fibrosis were determined in CCl4-induced liver toxicity in rats. Compared with the sham group, the liver function was worse in CCl4 group, manifested as increased levels of serum alanine aminotransferase, aspartate aminotransferase and total bilirubin. EPP and EPS treatment significantly ameliorated these effects of CCl4. EPP and EPS attenuated CCl4-induced increase in the levels of TGF-β1, hydroxyproline, hyaluronic acid laminin and procollagen type III. They also restored the decreased superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities and inhibited the formation of lipid peroxidized products in rats treated with CCl4. The EPP and EPS have protective effects against liver fibrosis induced by CCl4, and its mechanisms might be associated with their antioxidant activity, the ability of decreasing the level of TGF-β1 and inhibition of collagen synthesis.
Ghazanfari, Nazanin; Morsch, Marco; Reddel, Stephen W; Liang, Simon X; Phillips, William D
2014-01-01
Muscle-specific kinase (MuSK) autoantibodies from myasthenia gravis patients can block the activation of MuSK in vitro and/or reduce the postsynaptic localization of MuSK. Here we use a mouse model to examine the effects of MuSK autoantibodies upon some key components of the postsynaptic MuSK pathway and upon the regulation of junctional ACh receptor (AChR) numbers. Mice became weak after 14 daily injections of anti-MuSK-positive patient IgG. The intensity and area of AChR staining at the motor endplate was markedly reduced. Pulse-labelling of AChRs revealed an accelerated loss of pre-existing AChRs from postsynaptic AChR clusters without a compensatory increase in incorporation of (newly synthesized) replacement AChRs. Large, postsynaptic AChR clusters were replaced by a constellation of tiny AChR microaggregates. Puncta of AChR staining also appeared in the cytoplasm beneath the endplate. Endplate staining for MuSK, activated Src, rapsyn and AChR were all reduced in intensity. In the tibialis anterior muscle there was also evidence that phosphorylation of the AChR β-subunit-Y390 was reduced at endplates. In contrast, endplate staining for β-dystroglycan (through which rapsyn couples AChR to the synaptic basement membrane) remained intense. The results suggest that anti-MuSK IgG suppresses the endplate density of MuSK, thereby down-regulating MuSK signalling activity and the retention of junctional AChRs locally within the postsynaptic membrane scaffold. PMID:24860174
Identifying osteoporotic vertebral endplate and cortex fractures
Santiago, Fernando Ruiz; Deng, Min; Nogueira-Barbosa, Marcello H.
2017-01-01
Osteoporosis is the most common metabolic bone disease, and vertebral fractures (VFs) are the most common osteoporotic fracture. A single atraumatic VF may lead to the diagnosis of osteoporosis. Prevalent VFs increase the risk of future vertebral and non-vertebral osteoporotic fracture independent of bone mineral density (BMD). The accurate and clear reporting of VF is essential to ensure patients with osteoporosis receive appropriate treatment. Radiologist has a vital role in the diagnosis of this disease. Several morphometrical and radiological methods for detecting osteoporotic VF have been proposed, but there is no consensus regarding the definition of osteoporotic VF. A vertebra may fracture yet not ever result in measurable changes in radiographic height or area. To overcome these difficulties, algorithm-based qualitative approach (ABQ) was developed with a focus on the identification of change in the vertebral endplate. Evidence of endplate fracture (rather than variation in vertebral shape) is the primary indicator of osteoporotic fracture according to ABQ criteria. Other changes that may mimic osteoporotic fractures should be systemically excluded. It is also possible that vertebral cortex fracture may not initially occur in endplate. Particularly, vertebral cortex fracture can occur in anterior vertebral cortex without gross vertebral deformity (VD), or fractures deform the anterior vertebral cortex without endplate disruption. This article aims to serve as a teaching material for physicians or researchers to identify vertebral endplate/cortex fracture (ECF). Emphasis is particularly dedicated to identifying ECF which may not be associated apparent vertebral body collapse. We believe a combined approach based on standardized radiologic evaluation by experts and morphometry measurement is the most appropriate approach to detect and classify VFs. PMID:29184768
Giniatullin, R A; Talantova, M; Vyskocil, F
1997-08-01
1. The desensitization induced by bath-applied carbachol or acetylcholine (ACh) and potentiated by proadifen (SKF 525A) was studied in the frog sartorius with intact synaptic acetylcholinesterase (AChE). 2. The reduction in the density and number of postsynaptic receptors produced by desensitization lowered the amplitude of the endplate currents (EPCs) and shortened the EPC decay when the quantal content (m) of the EPC was about 170 and when multiple release of quanta at single active zones was highly probably. The shortening of high-quantal-content EPCs persisted for at least 15 min after the wash-out of agonists, at a time when the amplitude had recovered fully. 3. The decay times of the low-quantal-content EPCs recorded from preparations pretreated with 5 mM Mg2+ (m approximately 70) and single-quantum miniature endplate currents (MEPCs) were not affected by carbachol, ACh or proadifen. 4. The desensitization of ACh receptors potentiated by proadifen, prevented completely the 6- to 8-fold prolongation of EPC which was induced by neostigmine inhibition of synaptic AChE. 5. It is assumed that high-quantal-content EPCs increase the incidence of multiple quanta release at single active zones and the probability of repetitive binding of ACh molecules which leads to EPC prolongation. The shortening which persists after complete recovery of the amplitude during wash-out of the exogenous agonist is probably due to 'trapping' of ACh molecules onto rapidly desensitized receptors and the reduced density of functional AChRs during the quantum action.
The Teaching of the Code of Ethics and Standard Practices for Texas Educator Preparation Programs
ERIC Educational Resources Information Center
Davenport, Marvin; Thompson, J. Ray; Templeton, Nathan R.
2015-01-01
The purpose of this descriptive quantitative research study was to answer three basic informational questions: (1) To what extent ethics training, as stipulated in Texas Administrative Code Chapter 247, was included in the EPP curriculum; (2) To what extent Texas public universities with approved EPP programs provided faculty opportunities for…
RESEARCH ON EFFECTS OF ACETYLCHOLINE ON THE MAMMALIAN MOTOR END-PLATE
presumably through the release of a chemical mediator. (3) The chemical sensitivity of end-plate receptors in muscles from patients with myasthenia ... gravis is normal, suggesting that the neuromuscular defect in this disease is of pre-junctional origin.
Human Disc Nucleus Properties and Vertebral Endplate Permeability
Rodriguez, Azucena G.; Slichter, Chloe K.; Acosta, Frank L.; Rodriguez-Soto, Ana E.; Burghardt, Andrew J.; Majumdar, Sharmila; Lotz, Jeffrey C.
2010-01-01
Study of human cadaveric discs quantifying endplate permeability and porosity and correlating these with measures of disc quality: cell density, proteoglycan content, and overall degeneration. Permeability and porosity increased with age and were not correlated with cell density or overall degeneration, suggesting that endplate calcification may not accelerate disc degeneration. Study Design Experimental quantification of relationships between vertebral endplate morphology, permeability, disc cell density, glycosaminoglycan content and degeneration in samples harvested from human cadaveric spines. Objective To test the hypothesis that variation in endplate permeability and porosity contribute to changes in intervertebral disc cell density and overall degeneration. Summary of Background Data Cells within the intervertebral disc are dependent on diffusive exchange with capillaries in the adjacent vertebral bone. Previous findings suggest that blocked routes of transport negatively affect disc quality, yet there are no quantitative relationships between human vertebral endplate permeability, porosity, cell density and disc degeneration. Such relationships would be valuable for clarifying degeneration risk factors, and patient features that may impede efforts at disc tissue engineering. Methods Fifty-one motion segments were harvested from 13 frozen cadaveric human lumbar spines (32 to 85 years) and classified for degeneration using the MRI-based Pfirrmann scale. A cylindrical core was harvested from the center of each motion segment that included vertebral bony and cartilage endplates along with adjacent nucleus tissue. The endplate mobility, a type of permeability, was measured directly using a custom-made permeameter before and after the cartilage endplate was removed. Cell density within the nucleus tissue was estimated using the picogreen method while the nuclear GAG content was quantified using the DMMB technique. Specimens were imaged at 8 μm resolution using microCT, bony porosity was calculated. Analysis of variance, linear regression, and multiple comparison tests were used to analyze the data. Results Nucleus cell density increased as the disc height decreased (R2=0.13; p=0.01) but was not related to subchondral bone porosity (p>0.5), total mobility (p>0.4) or age (p>0.2). When controlling for disc height however, a significant, negative effect of age on cell density was observed (p=0.03). In addition to this, GAG content decreased with age non-linearly (R2=0.83, p<0.0001) and a cell function measurement, GAGs/cell decreased with degeneration (R2=0.24; p<0.0001). Total mobility (R2=0.14; p<0.01) and porosity (R2=0.1, p<0.01) had a positive correlation with age. Conclusion Although cell density increased with degeneration, cell function indicated that GAGs/cell decreased. Since permeability and porosity increase with age and degeneration, this implies that cell dysfunction, rather than physical barriers to transport, accelerate disc disease. PMID:21240044
Ryu, Robert; Techy, Fernando; Varadarajan, Ravikumar; Amirouche, Farid
2016-02-01
To study effects (stress loads) of lumbar fusion on the remaining segments (adjacent or not) of the lumbar spine in the setting of degenerated adjacent discs. A lumbar spine finite element model was built and validated. The full model of the lumbar spine was a parametric finite element model of segments L 1-5 . Numerous hypothetical combinations of one-level lumbar spine fusion and one-level disc degeneration were created. These models were subjected to 10 Nm flexion and extension moments and the stresses on the endplates and consequently on the intervertebral lumbar discs measured. These values were compared to the stresses on healthy lumbar spine discs under the same load and fusion scenarios. Increased stress at endplates was observed only in the settings of L4-5 fusion and L3-4 disc degeneration (8% stress elevation at L2,3 in flexion or extension, and 25% elevation at L3,4 in flexion only). All other combinations showed less endplate stress than did the control model. For fusion at L3-4 and degeneration at L4-5 , the stresses in the endplates at the adjacent level inferior to the fused disc decreased for both loading disc height reductions. Stresses in flexion decreased after fusion by 29.5% and 25.8% for degeneration I and II, respectively. Results for extension were similar. For fusion at L2-3 and degeneration at L4-5 , stresses in the endplates decreased more markedly at the degenerated (30%), than at the fused level (14%) in the presence of 25% disc height reduction and 10 Nm flexion, whereas in extension stresses decreased more at the fused (24.3%) than the degenerated level (5.86%). For fusion at L3-4 and degeneration at L2-3 , there were no increases in endplate stress in any scenario. For fusion at L4-5 and degeneration at L3-4 , progression of degeneration from I to II had a significant effect only in flexion. A dramatic increase in stress was noted in the endplates of the degenerated disc (L3-4 ) in flexion for degeneration II. Stresses are greater in flexion at the endplates of L3-4 and in flexion and extension at L2-3 in the presence of L3-4 disc disease and L4-5 fusion than in the control group. In all other combinations of fusion and disc disease, endplate stress was less for all levels tested than in the control model. © 2016 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.
Personal protective equipment for the Ebola virus disease: A comparison of 2 training programs.
Casalino, Enrique; Astocondor, Eugenio; Sanchez, Juan Carlos; Díaz-Santana, David Enrique; Del Aguila, Carlos; Carrillo, Juan Pablo
2015-12-01
Personal protective equipment (PPE) for preventing Ebola virus disease (EVD) includes basic PPE (B-PPE) and enhanced PPE (E-PPE). Our aim was to compare conventional training programs (CTPs) and reinforced training programs (RTPs) on the use of B-PPE and E-PPE. Four groups were created, designated CTP-B, CTP-E, RTP-B, and RTP-E. All groups received the same theoretical training, followed by 3 practical training sessions. A total of 120 students were included (30 per group). In all 4 groups, the frequency and number of total errors and critical errors decreased significantly over the course of the training sessions (P < .01). The RTP was associated with a greater reduction in the number of total errors and critical errors (P < .0001). During the third training session, we noted an error frequency of 7%-43%, a critical error frequency of 3%-40%, 0.3-1.5 total errors, and 0.1-0.8 critical errors per student. The B-PPE groups had the fewest errors and critical errors (P < .0001). Our results indicate that both training methods improved the student's proficiency, that B-PPE appears to be easier to use than E-PPE, that the RTP achieved better proficiency for both PPE types, and that a number of students are still potentially at risk for EVD contamination despite the improvements observed during the training. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
FY16 Status Report on Development of Integrated EPP and SMT Design Methods
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jetter, R. I.; Sham, T. -L.; Wang, Y.
2016-08-01
The goal of the Elastic-Perfectly Plastic (EPP) combined integrated creep-fatigue damage evaluation approach is to incorporate a Simplified Model Test (SMT) data based approach for creep-fatigue damage evaluation into the EPP methodology to avoid the separate evaluation of creep and fatigue damage and eliminate the requirement for stress classification in current methods; thus greatly simplifying evaluation of elevated temperature cyclic service. The EPP methodology is based on the idea that creep damage and strain accumulation can be bounded by a properly chosen “pseudo” yield strength used in an elastic-perfectly plastic analysis, thus avoiding the need for stress classification. The originalmore » SMT approach is based on the use of elastic analysis. The experimental data, cycles to failure, is correlated using the elastically calculated strain range in the test specimen and the corresponding component strain is also calculated elastically. The advantage of this approach is that it is no longer necessary to use the damage interaction, or D-diagram, because the damage due to the combined effects of creep and fatigue are accounted in the test data by means of a specimen that is designed to replicate or bound the stress and strain redistribution that occurs in actual components when loaded in the creep regime. The reference approach to combining the two methodologies and the corresponding uncertainties and validation plans are presented. Results from recent key feature tests are discussed to illustrate the applicability of the EPP methodology and the behavior of materials at elevated temperature when undergoing stress and strain redistribution due to plasticity and creep.« less
Reducing School Factors That Lead to Student Dropout at Sussex Central High School
ERIC Educational Resources Information Center
Jerns, Pamela Renee
2012-01-01
The focus of this Executive Position Paper (EPP) is to address the dropout rate at Sussex Central High School (SCHS) in the Indian River School District (IRSD). Studies conducted for this EPP align with current research--student dropout is a result of culminating school-based factors that include poor attendance and lack of exposure to rigorous…
Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-18
... Officer (ECO); and (5) the retention by BlackRock of an Independent Monitor (IM). The purpose of these... parties. The EPPs are to be developed with the cooperation of both the ECO and the IM, and such EPPs are... constitute Violations. The ECO will make a written determination as to whether such transgressions constitute...
Ghazanfari, Nazanin; Morsch, Marco; Reddel, Stephen W; Liang, Simon X; Phillips, William D
2014-07-01
Muscle-specific kinase (MuSK) autoantibodies from myasthenia gravis patients can block the activation of MuSK in vitro and/or reduce the postsynaptic localization of MuSK. Here we use a mouse model to examine the effects of MuSK autoantibodies upon some key components of the postsynaptic MuSK pathway and upon the regulation of junctional ACh receptor (AChR) numbers. Mice became weak after 14 daily injections of anti-MuSK-positive patient IgG. The intensity and area of AChR staining at the motor endplate was markedly reduced. Pulse-labelling of AChRs revealed an accelerated loss of pre-existing AChRs from postsynaptic AChR clusters without a compensatory increase in incorporation of (newly synthesized) replacement AChRs. Large, postsynaptic AChR clusters were replaced by a constellation of tiny AChR microaggregates. Puncta of AChR staining also appeared in the cytoplasm beneath the endplate. Endplate staining for MuSK, activated Src, rapsyn and AChR were all reduced in intensity. In the tibialis anterior muscle there was also evidence that phosphorylation of the AChR β-subunit-Y390 was reduced at endplates. In contrast, endplate staining for β-dystroglycan (through which rapsyn couples AChR to the synaptic basement membrane) remained intense. The results suggest that anti-MuSK IgG suppresses the endplate density of MuSK, thereby down-regulating MuSK signalling activity and the retention of junctional AChRs locally within the postsynaptic membrane scaffold. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.
FY16 Progress Report on Test Results In Support Of Integrated EPP and SMT Design Methods Development
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Yanli; Jetter, Robert I.; Sham, T. -L.
2016-08-08
The proposed integrated Elastic Perfectly-Plastic (EPP) and Simplified Model Test (SMT) methodology consists of incorporating an SMT data-based approach for creep-fatigue damage evaluation into the EPP methodology to avoid using the creep-fatigue interaction diagram (the D diagram) and to minimize over-conservatism while properly accounting for localized defects and stress risers. To support the implementation of the proposed code rules and to verify their applicability, a series of thermomechanical tests have been initiated. This report presents the recent test results for Type 2 SMT specimens on Alloy 617, Pressurization SMT on Alloy 617, Type 1 SMT on Gr. 91, and two-barmore » thermal ratcheting test results on Alloy 617 with a new thermal loading profile.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Muresan, Ioana Cristina; Balc, Roxana
Beam-to-column end-plate bolted connections are usually used as moment-resistant connections in steel framed structures. For this joint type, the deformability is governed by the deformation capacity of the column flange and end-plate under tension and elongation of the bolts. All these elements around the beam tension flange form the tension region of the joint, which can be modeled by means of equivalent T-stubs. In this paper a beam-to-column end-plate bolted connection is substituted with a T-stub of appropriate effective length and it is analyzed using the commercially available finite element software ABAQUS. The performance of the model is validated bymore » comparing the behavior of the T-stub from the numerical simulation with the behavior of the connection as a whole. The moment-rotation curve of the T-stub obtained from the numerical simulation is compared with the behavior of the whole extended end-plate connection, obtained by numerical simulation, experimental tests and analytical approach.« less
Mattei, Tobias A
2017-06-01
Previous studies have demonstrated lower rates of cement extravasation when comparing balloon kyphoplasty with vertebroplasty, an effect attributed to the low-pressure injection. However, in patients with isolated endplate fractures, balloon kyphoplasty may lead to further endplate damage and increased risks of intradiscal extravasation. The author provides a stepwise description of a new technique called cavitational kyphoplasty that allows targeted low-pressure cement injection without the necessity of balloon inflation. The new technique of cavitational kyphoplasty has been shown to be specially useful in patients with isolated endplate fractures without significant loss of the vertebral body height.
Creating a More Inclusive Talent Pool for the GeoSciences in NOAA Mission Fields:
NASA Astrophysics Data System (ADS)
Rousseau, J.; Trotman, A. A.
2014-12-01
The National Oceanic and Atmospheric Administration (NOAA) Educational Partnership Program (EPP) with Minority Serving Institutions (MSI) is recognized as a model federal Science, Technology, Engineering, and Mathematics, (STEM) education investment. The EPP has a premier goal of increasing the numbers of students, especially from underrepresented communities, who are trained and awarded degrees in NOAA mission-relevant STEM fields. This goal is being achieved through awards to support undergraduate and graduate level student scholarships and to enhance NOAA mission-relevant education, research and internships at EPP Cooperative Science Centers located at MSIs. The internships allow undergraduate students to gain technical experience in STEM fields while gaining an understanding of a science mission agency such as NOAA. EPP has built evidence supporting the value of internships with its Undergraduate Scholarship Program (USP). Program metrics are used to refine and improve the internship to ensure student success. Scholarships are competitively awarded and requires applicants to submit a personal statement detailing the NOAA-relevant professional experience the applicant seeks to acquire, and gauges the depth of understanding of the work of NOAA.A focus is the EPP USP Student Internship at NOAA, which has two training phases. The first occurs at NOAA HQ in Maryland and incorporates exposure to NOAA professional culture including mentoring and professional development for scholarship recipients. The second occurs at NOAA facilities in the 50 states and US Territories. The internship projects are conducted under the supervision of a NOAA mentor and allow the scholars to: acquire increased science and technology skills: be attached to a research group and participate in a research activity as part of the team; and, acquire practical experience and knowledge of the day-to-day work of the NOAA facility. EPP has recently initiated the Experiential Research and Training Opportunities (NERTO) for students from the CSCs. The NERTO is a longer term immersion at NOAA facilities, with a NOAA mentor working collaboratively with their academic advisor on a NOAA science priority. Consequently, the NERTO is strengthening the undergraduate to graduate education and workforce pipeline.
Serrano-León, Juan S; Bergamaschi, Keityane B; Yoshida, Cristiana M P; Saldaña, Erick; Selani, Miriam M; Rios-Mera, Juan D; Alencar, Severino M; Contreras-Castillo, Carmen J
2018-06-01
This study aimed to develop chitosan films incorporating natural antioxidants from peanut skin (EPS) and pink pepper residue (EPP) extracts, as well as to evaluate their effects on lipid oxidation, pH, color, and microbial counts of a restructured chicken product. EPS had higher phenolic content and antioxidant activity compared to EPP. When both extracts were applied to chicken meat and the chitosan films, there were no differences for color, pH and total mesophilic counts compared to control at the end of the storage period. For lipid oxidation (peroxide value and thiobarbituric acid reactive substances), both extracts proved to be as effective as butylated hydroxytoluene to maintain the oxidative stability of the chicken product. The microbial counts of psychrotrophic microorganisms were significantly lower for treatments with active films. Chitosan active films with residue extracts may maintain the quality of chicken products due to their antioxidant and antimicrobial potential. Copyright © 2018 Elsevier Ltd. All rights reserved.
Indian hedgehog contributes to human cartilage endplate degeneration.
Wang, Shaowei; Yang, Kun; Chen, Shuai; Wang, Jiying; Du, Guoqing; Fan, Shunwu; Wei, Lei
2015-08-01
To determine the role of Indian hedgehog (Ihh) signaling in human cartilage endplate (CEP) degeneration. CEP-degenerated tissues from patients with Modic I or II changes (n = 9 and 45, respectively) and normal tissues from vertebral burst fracture patients (n = 17) were collected. Specimens were either cut into slices for organ culture ex vivo or digested to isolate chondrocytes for cell culture in vitro. Ihh expression and the effect of Ihh on cartilage degeneration were determined by investigating degeneration markers in this study. Ihh expression and cartilage degeneration markers significantly increased in the Modic I and II groups. The expression of cartilage degeneration markers was positively correlated with degeneration severity. Gain-of-function for Ihh promoted expression of cartilage degeneration markers in vitro, while loss-of-function for Ihh inhibited their expression both in vitro and ex vivo. These findings demonstrated that Ihh promotes CEP degeneration. Blocking Ihh pathway has potential clinical usage for attenuating CEP degeneration.
Hasegawa, Seiki; Okada, Morihito; Tanaka, Fumihiro; Yamanaka, Takeharu; Soejima, Toshinori; Kamikonya, Norihiko; Tsujimura, Tohru; Fukuoka, Kazuya; Yokoi, Kohei; Nakano, Takashi
2016-06-01
We conducted a prospective multi-institutional study to determine the feasibility of trimodality therapy (TMT) comprising induction chemotherapy followed by extrapleural pneumonectomy (EPP) and radiation therapy in Japanese patients with malignant pleural mesothelioma (MPM). Major eligibility criteria were histologically confirmed diagnosis of MPM, including clinical subtypes T0-3, N0-2, M0 disease; no prior treatment for the disease; age 20-75 years; Eastern Cooperative Oncology Group performance status 0 or 1; predicted postoperative forced expiratory volume >1000 ml in 1 s; written informed consent. Treatment methods comprised induction chemotherapy using pemetrexed (500 mg/m(2)) plus cisplatin (60 mg/m(2)) for three cycles, followed by EPP and postoperative hemithoracic radiation therapy (54 Gy). Primary endpoints were macroscopic complete resection (MCR) rate for EPP and treatment-related mortality for TMT. Forty-two eligible patients were enrolled: median age 64.5 (range 43-74) years; M:F = 39:3, clinical stage I:II:III = 14:13:15; histological type epithelioid were sarcomatoid; biphasic; others = 28:1:9:4. Of 42 patients, 30 completed EPP with MCR and 17 completed TMT. The trial met the primary endpoints, with an MCR rate of 71 % (30/42) and treatment-related mortality of 9.5 % (4/42). Overall median survival time and 2-year survival rate for 42 registered patients were 19.9 months and 42.9 %, respectively. Two-year relapse-free survival rate of 30 patients who completed EPP with MCR was 37.0 %. This phase II study met the predefined primary endpoints, but its risk/benefit ratio was not satisfactory.
Extrapleural pneumonectomy for malignant mesothelioma: an Italian multicenter retrospective study.
Spaggiari, Lorenzo; Marulli, Giuseppe; Bovolato, Pietro; Alloisio, Marco; Pagan, Vittore; Oliaro, Alberto; Ratto, Giovanni Battista; Facciolo, Francesco; Sacco, Rocco; Brambilla, Daniela; Maisonneuve, Patrick; Mucilli, Felice; Alessandrini, Gabriele; Leoncini, Giacomo; Ruffini, Enrico; Fontana, Paolo; Infante, Maurizio; Pariscenti, Gian Luca; Casiraghi, Monica; Rea, Federico
2014-06-01
This study assessed perioperative outcome and long-term survival in a large series of patients with malignant pleural mesothelioma who underwent extrapleural pneumonectomy (EPP) to identify prognostic factors allowing better patient selection. We retrospectively collected data from nine referral centers for thoracic surgery in Italy. Perioperative outcome and survival data were available for 518 malignant pleural mesothelioma patients (84.4% with epithelial tumors, 68.0% with pathologic stage 3 disease) who underwent EPP with intention-to-treat (R0/R1) between 2000 and 2010. Induction chemotherapy was administered in 271 patients (52.3%) and adjuvant therapy in 373 patients (72.0%), including radiotherapy in 213 patients (41.1%), adjuvant chemotherapy in 43 patients (8.3%), and both in 117 patients (22.6%). In all, 136 patients (26.3%) had major complications after EPP, and 36 (6.9%) died within 90 days after surgery. The median overall survival was 18 months, with a 1-, 2-, and 3-year overall survival of 65%, 41%, and 27%, respectively. At multivariable analysis adjusted for age and disease stage, male sex (hazard ratio [HR] 1.47, 95% confidence interval [CI]: 1.12 to 1.92), nonepithelial histology (HR 1.96, 95% CI: 1.48 to 2.58), and trimodality treatment using induction chemotherapy (HR 0.61, 95% CI: 0.43 to 0.85) were significantly associated with survival. Development of a major complication also significantly worsened outcome (HR 1.85, 95% CI: 1.37 to 2.50). The success of EPP in the context of a multimodality treatment depends on a series of patient characteristics. Female patients, patients with epithelial tumors, and patients who received induction chemotherapy will best benefit from EPP. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.
Martinez-Enriquez, Eduardo; Sun, Mengchan; Velasco-Ocana, Miriam; Birkenfeld, Judith; Pérez-Merino, Pablo; Marcos, Susana
2016-07-01
Measurement of crystalline lens geometry in vivo is critical to optimize performance of state-of-the-art cataract surgery. We used custom-developed quantitative anterior segment optical coherence tomography (OCT) and developed dedicated algorithms to estimate lens volume (VOL), equatorial diameter (DIA), and equatorial plane position (EPP). The method was validated ex vivo in 27 human donor (19-71 years of age) lenses, which were imaged in three-dimensions by OCT. In vivo conditions were simulated assuming that only the information within a given pupil size (PS) was available. A parametric model was used to estimate the whole lens shape from PS-limited data. The accuracy of the estimated lens VOL, DIA, and EPP was evaluated by comparing estimates from the whole lens data and PS-limited data ex vivo. The method was demonstrated in vivo using 2 young eyes during accommodation and 2 cataract eyes. Crystalline lens VOL was estimated within 96% accuracy (average estimation error across lenses ± standard deviation: 9.30 ± 7.49 mm3). Average estimation errors in EPP were below 40 ± 32 μm, and below 0.26 ± 0.22 mm in DIA. Changes in lens VOL with accommodation were not statistically significant (2-way ANOVA, P = 0.35). In young eyes, DIA decreased and EPP increased statistically significantly with accommodation (P < 0.001) by 0.14 mm and 0.13 mm, respectively, on average across subjects. In cataract eyes, VOL = 205.5 mm3, DIA = 9.57 mm, and EPP = 2.15 mm on average. Quantitative OCT with dedicated image processing algorithms allows estimation of human crystalline lens volume, diameter, and equatorial lens position, as validated from ex vivo measurements, where entire lens images are available.
NWP model forecast skill optimization via closure parameter variations
NASA Astrophysics Data System (ADS)
Järvinen, H.; Ollinaho, P.; Laine, M.; Solonen, A.; Haario, H.
2012-04-01
We present results of a novel approach to tune predictive skill of numerical weather prediction (NWP) models. These models contain tunable parameters which appear in parameterizations schemes of sub-grid scale physical processes. The current practice is to specify manually the numerical parameter values, based on expert knowledge. We developed recently a concept and method (QJRMS 2011) for on-line estimation of the NWP model parameters via closure parameter variations. The method called EPPES ("Ensemble prediction and parameter estimation system") utilizes ensemble prediction infra-structure for parameter estimation in a very cost-effective way: practically no new computations are introduced. The approach provides an algorithmic decision making tool for model parameter optimization in operational NWP. In EPPES, statistical inference about the NWP model tunable parameters is made by (i) generating an ensemble of predictions so that each member uses different model parameter values, drawn from a proposal distribution, and (ii) feeding-back the relative merits of the parameter values to the proposal distribution, based on evaluation of a suitable likelihood function against verifying observations. In this presentation, the method is first illustrated in low-order numerical tests using a stochastic version of the Lorenz-95 model which effectively emulates the principal features of ensemble prediction systems. The EPPES method correctly detects the unknown and wrongly specified parameters values, and leads to an improved forecast skill. Second, results with an ensemble prediction system emulator, based on the ECHAM5 atmospheric GCM show that the model tuning capability of EPPES scales up to realistic models and ensemble prediction systems. Finally, preliminary results of EPPES in the context of ECMWF forecasting system are presented.
2001-01-01
ofAcetylcholinesterase at Motor Endplates John P. Petrali and Kenneth R. Mills INTRODUCTION Acetylcholinesterase (AChE) is the modulating enzyme of cholin ...utilized for this study was the Pelco 3440, 800 W. The animal used was the haired guinea pig, which was euthanatized by an overdose of Na pentobarbital
Low rate loading-induced convection enhances net transport into the intervertebral disc in vivo.
Gullbrand, Sarah E; Peterson, Joshua; Mastropolo, Rosemarie; Roberts, Timothy T; Lawrence, James P; Glennon, Joseph C; DiRisio, Darryl J; Ledet, Eric H
2015-05-01
The intervertebral disc primarily relies on trans-endplate diffusion for the uptake of nutrients and the clearance of byproducts. In degenerative discs, diffusion is often diminished by endplate sclerosis and reduced proteoglycan content. Mechanical loading-induced convection has the potential to augment diffusion and enhance net transport into the disc. The ability of convection to augment disc transport is controversial and has not been demonstrated in vivo. To determine if loading-induced convection can enhance small molecule transport into the intervertebral disc in vivo. Net transport was quantified via postcontrast enhanced magnetic resonance imaging (MRI) into the discs of the New Zealand white rabbit lumbar spine subjected to in vivo cyclic low rate loading. Animals were administered the MRI contrast agent gadodiamide intravenously and subjected to in vivo low rate loading (0.5 Hz, 200 N) via a custom external loading apparatus for either 2.5, 5, 10, 15, or 20 minutes. Animals were then euthanized and the lumbar spines imaged using postcontrast enhanced MRI. The T1 constants in the nucleus, annulus, and cartilage endplates were quantified as a measure of gadodiamide transport into the loaded discs compared with the adjacent unloaded discs. Microcomputed tomography was used to quantify subchondral bone density. Low rate loading caused the rapid uptake and clearance of gadodiamide in the nucleus compared with unloaded discs, which exhibited a slower rate of uptake. Relative to unloaded discs, low rate loading caused a maximum increase in transport into the nucleus of 16.8% after 5 minutes of loading. Low rate loading increased the concentration of gadodiamide in the cartilage endplates at each time point compared with unloaded levels. Results from this study indicate that forced convection accelerated small molecule uptake and clearance in the disc induced by low rate mechanical loading. Low rate loading may, therefore, be therapeutic to the disc as it may enhance the nutrient uptake and waste product clearance. Copyright © 2015 Elsevier Inc. All rights reserved.
Kaiser, Sara A.; Sillett, T. Scott; Risk, Benjamin B.; Webster, Michael S.
2015-01-01
Environmental factors can shape reproductive investment strategies and influence the variance in male mating success. Environmental effects on extrapair paternity have traditionally been ascribed to aspects of the social environment, such as breeding density and synchrony. However, social factors are often confounded with habitat quality and are challenging to disentangle. We used both natural variation in habitat quality and a food supplementation experiment to separate the effects of food availability—one key aspect of habitat quality—on extrapair paternity (EPP) and reproductive success in the black-throated blue warbler, Setophaga caerulescens. High natural food availability was associated with higher within-pair paternity (WPP) and fledging two broods late in the breeding season, but lower EPP. Food-supplemented males had higher WPP leading to higher reproductive success relative to controls, and when in low-quality habitat, food-supplemented males were more likely to fledge two broods but less likely to gain EPP. Our results demonstrate that food availability affects trade-offs in reproductive activities. When food constraints are reduced, males invest in WPP at the expense of EPP. These findings imply that environmental change could alter how individuals allocate their resources and affect the selective environment that drives variation in male mating success. PMID:25673677
EMG and EPP-integrated human-machine interface between the paralyzed and rehabilitation exoskeleton.
Yin, Yue H; Fan, Yuan J; Xu, Li D
2012-07-01
Although a lower extremity exoskeleton shows great prospect in the rehabilitation of the lower limb, it has not yet been widely applied to the clinical rehabilitation of the paralyzed. This is partly caused by insufficient information interactions between the paralyzed and existing exoskeleton that cannot meet the requirements of harmonious control. In this research, a bidirectional human-machine interface including a neurofuzzy controller and an extended physiological proprioception (EPP) feedback system is developed by imitating the biological closed-loop control system of human body. The neurofuzzy controller is built to decode human motion in advance by the fusion of the fuzzy electromyographic signals reflecting human motion intention and the precise proprioception providing joint angular feedback information. It transmits control information from human to exoskeleton, while the EPP feedback system based on haptic stimuli transmits motion information of the exoskeleton back to the human. Joint angle and torque information are transmitted in the form of air pressure to the human body. The real-time bidirectional human-machine interface can help a patient with lower limb paralysis to control the exoskeleton with his/her healthy side and simultaneously perceive motion on the paralyzed side by EPP. The interface rebuilds a closed-loop motion control system for paralyzed patients and realizes harmonious control of the human-machine system.
A simple microstructure return model explaining microstructure noise and Epps effects
NASA Astrophysics Data System (ADS)
Saichev, A.; Sornette, D.
2014-01-01
We present a novel simple microstructure model of financial returns that combines (i) the well-known ARFIMA process applied to tick-by-tick returns, (ii) the bid-ask bounce effect, (iii) the fat tail structure of the distribution of returns and (iv) the non-Poissonian statistics of inter-trade intervals. This model allows us to explain both qualitatively and quantitatively important stylized facts observed in the statistics of both microstructure and macrostructure returns, including the short-ranged correlation of returns, the long-ranged correlations of absolute returns, the microstructure noise and Epps effects. According to the microstructure noise effect, volatility is a decreasing function of the time-scale used to estimate it. The Epps effect states that cross correlations between asset returns are increasing functions of the time-scale at which the returns are estimated. The microstructure noise is explained as the result of the negative return correlations inherent in the definition of the bid-ask bounce component (ii). In the presence of a genuine correlation between the returns of two assets, the Epps effect is due to an average statistical overlap of the momentum of the returns of the two assets defined over a finite time-scale in the presence of the long memory process (i).
Parametric study of extended end-plate connection using finite element modeling
NASA Astrophysics Data System (ADS)
Mureşan, Ioana Cristina; Bâlc, Roxana
2017-07-01
End-plate connections with preloaded high strength bolts represent a convenient, fast and accurate solution for beam-to-column joints. The behavior of framework joints build up with this type of connection are sensitive dependent on geometrical and material characteristics of the elements connected. This paper presents results of parametric analyses on the behavior of a bolted extended end-plate connection using finite element modeling program Abaqus. This connection was experimentally tested in the Laboratory of Faculty of Civil Engineering from Cluj-Napoca and the results are briefly reviewed in this paper. The numerical model of the studied connection was described in detail in [1] and provides data for this parametric study.
2011-01-01
in the number of quanta released per impulse or a reduction in the desensitization rate of AChRs, which are potentially adaptive, do not seem to occur... potential , Medical chemical defense 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON...must adapt to allow for survival of the organism in the absence of AChE. Nerve-elicited muscle contractions, miniature endplate potentials (MEPPs) and
Degenerative changes of the canine cervical spine after discectomy procedures, an in vivo study.
Grunert, Peter; Moriguchi, Yu; Grossbard, Brian P; Ricart Arbona, Rodolfo J; Bonassar, Lawrence J; Härtl, Roger
2017-06-23
Discectomies are a common surgical treatment for disc herniations in the canine spine. However, the effect of these procedures on intervertebral disc tissue is not fully understood. The objective of this study was to assess degenerative changes of cervical spinal segments undergoing discectomy procedures, in vivo. Discectomies led to a 60% drop in disc height and 24% drop in foraminal height. Segments did not fuse but showed osteophyte formation as well as endplate sclerosis. MR imaging revealed terminal degenerative changes with collapse of the disc space and loss of T2 signal intensity. The endplates showed degenerative type II Modic changes. Quantitative MR imaging revealed that over 95% of Nucleus Pulposus tissue was extracted and that the nuclear as well as overall disc hydration significantly decreased. Histology confirmed terminal degenerative changes with loss of NP tissue, loss of Annulus Fibrosus organization and loss of cartilage endplate tissue. The bony endplate displayed sclerotic changes. Discectomies lead to terminal degenerative changes. Therefore, these procedures should be indicated with caution specifically when performed for prophylactic purposes.
Pan, Feng; Mi, Jing-Yi; Zhang, Yan; Pan, Xiao-Yun; Rui, Yong-Jun
2016-06-01
The failure to accept reinnervation is considered to be one of the reasons for the poor motor functional recovery of intrinsic hand muscles (IHMs) after nerve injury. Rat could be a suitable model to be used in simulating motor function recovery of the IHMs after nerve injury as to the similarities in function and anatomy of the muscles between human and rat. However, few studies have reported the muscle fiber types composition and endplate morphologic characteristics of intrinsic forepaw muscles (IFMs) in the rat. In this study, the myosin heavy chain isoforms and acetylcholine receptors were stained by immunofluorescence to show the muscle fiber types composition and endplates on type-identified fibers of the lumbrical muscles (LMs), interosseus muscles (IMs), abductor digiti minimi (AM) and flexor pollicis brevis (FM) in rat forepaw. The majority of IFMs fibers were labeled positively for fast-switch fiber. However, the IMs were composed of only slow-switch fiber. With the exception of the IMs, the other IFMs had a part of hybrid fibers. Two-dimensional morphological characteristics of endplates on I and IIa muscle fiber had no significant differences among the IFMs. The LMs is the most suitable IFMs of rat to stimulate reinnervation of the IHMs after nerve injury. Gaining greater insight into the muscle fiber types composition and endplate morphology in the IFMs of rat may help understand the pathological and functional changes of IFMs in rat model stimulating reinnervation of IHMs after peripheral nerve injury.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Du, Fang-Fang; Li, Tao; Long, Gui-Lu, E-mail: gllong@tsinghua.edu.cn
Hyperentanglement, defined as the entanglement in multiple degrees of freedom (DOFs) of a photonic quantum system, has attracted much attention recently as it can improve the channel capacity of quantum communication largely. Here we present a refined hyperentanglement purification protocol (hyper-EPP) for two-photon systems in mixed hyperentangled states in both the spatial-mode and polarization DOFs, assisted by cavity quantum electrodynamics. By means of the spatial (polarization) quantum state transfer process, the quantum states that are discarded in the previous hyper-EPPs can be preserved. That is, the spatial (polarization) state of a four-photon system with high fidelity can be transformed intomore » another four-photon system with low fidelity, not disturbing its polarization (spatial) state, which makes this hyper-EPP take the advantage of possessing a higher efficiency.« less
A Primer on Bayesian Analysis for Experimental Psychopathologists
Krypotos, Angelos-Miltiadis; Blanken, Tessa F.; Arnaudova, Inna; Matzke, Dora; Beckers, Tom
2016-01-01
The principal goals of experimental psychopathology (EPP) research are to offer insights into the pathogenic mechanisms of mental disorders and to provide a stable ground for the development of clinical interventions. The main message of the present article is that those goals are better served by the adoption of Bayesian statistics than by the continued use of null-hypothesis significance testing (NHST). In the first part of the article we list the main disadvantages of NHST and explain why those disadvantages limit the conclusions that can be drawn from EPP research. Next, we highlight the advantages of Bayesian statistics. To illustrate, we then pit NHST and Bayesian analysis against each other using an experimental data set from our lab. Finally, we discuss some challenges when adopting Bayesian statistics. We hope that the present article will encourage experimental psychopathologists to embrace Bayesian statistics, which could strengthen the conclusions drawn from EPP research. PMID:28748068
Multi-copy entanglement purification with practical spontaneous parametric down conversion sources
NASA Astrophysics Data System (ADS)
Zhang, Shuai-Shuai; Shu, Qi; Zhou, Lan; Sheng, Yu-Bo
2017-06-01
Entanglement purification is to distill the high quality entanglement from the low quality entanglement with local operations and classical communications. It is one of the key technologies in long-distance quantum communication. We discuss an entanglement purification protocol (EPP) with spontaneous parametric down conversion (SPDC) sources, in contrast to previous EPP with multi-copy mixed states, which requires ideal entanglement sources. We show that the SPDC source is not an obstacle for purification, but can benefit the fidelity of the purified mixed state. This EPP works for linear optics and is feasible in current experiment technology. Project supported by the National Natural Science Foundation of China (Grant Nos. 11474168 and 61401222), the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20151502), the Qing Lan Project in Jiangsu Province, China, and a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions, China.
2017-12-06
jsc2017e136942 - In the town of Baikonur, Kazakhstan, Expedition 54-55 backup crewmembers Jeanette Epps of NASA, Sergey Prokopyev of the Russian Federal Space Agency (Roscosmos) and Alexander Gerst of the European Space Agency lay flowers Dec. 6 at the sta
2017-12-06
jsc2017e136944 - In the town of Baikonur, Kazakhstan, Expedition 54-55 backup crewmembers Jeanette Epps of NASA, Sergey Prokopyev of the Russian Federal Space Agency (Roscosmos) and Alexander Gerst of the European Space Agency lay flowers Dec. 6 at the sta
X-linked dominant protoporphyria: The first reported Japanese case.
Ninomiya, Yukiko; Kokunai, Yasuhito; Tanizaki, Hideaki; Akasaka, Eijiro; Nakano, Hajime; Moriwaki, Shinichi
2016-04-01
A 12-year-old boy with photosensitivity since 3 years of age presented with small concavities on both cheeks, the nasal root and the dorsal surface of both hands. According to the clinical features, erythropoietic protoporphyria (EPP) was suspected. Urine and blood samples were tested for porphyrin derivatives, which revealed a markedly elevated level of erythrocyte protoporphyrin (EP) and a diagnosis of EPP was made. The patient's mother had no photosensitivity, however, lesions appearing slightly as small scars were found on the dorsum of her right hand; his elder sister and father showed no rash. The EP levels were elevated in samples from his mother and mildly elevated in those from his elder sister and father. To obtain a definitive diagnosis, genetic analyses were performed using samples from all family members, which revealed no mutations in the ferrochelatase-encoding gene (FECH), which is responsible for EPP. Instead, a pathological mutation of the 5-aminolevulinic acid synthase-encoding gene (ALAS2) was identified in samples from the patient, his mother and his elder sister, confirming a definitive diagnosis of X-linked dominant protoporphyria (XLDPP). This is the first Japanese family reported to have XLDPP, demonstrating evidence of the condition in Japan. In addition, because XLDPP is very similar to EPP in its clinical aspects and laboratory findings, a genetic analysis is required for the differential diagnosis. © 2015 Japanese Dermatological Association.
Sinclair, Sarina K; Bell, Spencer; Epperson, Richard Tyler; Bloebaum, Roy D
2013-05-01
To gain an understanding of the vertebral cortical endplate and factors that may affect the ability to achieve skeletal attachment to intervertebral implants and fusion, this study aimed to characterize the hypermineralized tissue on the cortical endplate of the vertebral body on a commonly used animal model. Skeletally mature sheep were injected with tetracycline prior to euthanasia and the C2-C3, T5-T6, and L2-L3 spinal motion segments were excised and prepared. Vertebral tissues were imaged using backscatter electron (BSE) imaging, histology, and tetracycline labeling was used to assess bone remodeling within different tissue layers. It was determined that the hypermineralized tissue layer was calcified fibrocartilage (CFC). No tetracycline labels were identified in the CFC layer, in contrast to single and double labels that were present in the underlying bone, indicating the CFC present on the cortical endplate was not being actively remodeled. The average thickness of the CFC layer was 146.3 ± 70.53 µm in the cervical region, 98.2 ± 40.29 µm in the thoracic region, and 150.89 ± 69.25 µm in the lumbar region. This difference in thickness may be attributed to the regional biomechanical properties of the spine. Results from this investigation indicate the presence of a nonremodeling tissue on the cortical endplate of the vertebral body in sheep spines, which attaches the intervertebral disc to the vertebrae. This tissue, if not removed, would likely prevent successful bony attachment to an intervertebral device in spinal fusion studies and total disc replacement surgeries. Copyright © 2013 Wiley Periodicals, Inc.
Uraoka, Hideyuki; Higashino, Kosaku; Morimoto, Masatoshi; Yamashita, Kazuta; Tezuka, Fumitake; Takata, Yoichiro; Sakai, Toshinori; Nagamachi, Akihiro; Murase, Masaaki; Sairyo, Koichi
2018-02-01
The lesion of the lumbar endplate is sometimes identified in the vertebrae of children and adolescents. The purpose of this study is to compare between skeletal maturity and chronological age. The second purpose of this study is to clarify the lesions of the lumbar endplate based on the maturation of the lumbar vertebral body. Six hundred and thirty-two (485 men and 147 women) consecutive patients were included. The mean age at the first medical examination was 13.8 years. Their skeletal maturity was evaluated based on the appearances of the secondary ossification center of L3. The area of the endplate lesions was classified into five types. The apophyseal stage was observed from 10 years old to 18 years old, and the apophyseal stage was shown the peak at 14 years old. The appearance of the apophyseal ring was observed earlier in female patients than in male patients. For the concave type, the lesion at upper level vertebra was more prevalent. The anterior and middle type of the lesion at upper level vertebra was more prevalent. For the posterior type, the lesion of the inferior rim of L4 and the lesion of the rim of L5 were more prevalent. This study emerged after comparing skeletal maturity based on the maturation of the lumbar vertebral body with the chronological age of a large number of patients and examining the lesions of the lumbar endplate based on the stage of maturation of the lumbar vertebral body.
Effect of prosthesis endplate lordosis angles on L5-S1 kinematics after disc arthroplasty.
Tsitsopoulos, Parmenion P; Wojewnik, Bartosz; Voronov, Leonard I; Havey, Robert M; Renner, Susan M; Zelenakova, Julia; McIntosh, Braden; Carandang, Gerard; Abjornson, Celeste; Patwardhan, Avinash G
2012-06-01
We hypothesized that L5-S1 kinematics will not be affected by the lordosis distribution between the prosthesis endplates. Twelve cadaveric lumbosacral spines (51.3 ± 9.8 years) were implanted with 6° or 11° prostheses (ProDisc-L) with four combinations of superior/inferior lordosis (6°/0°, 3°/3°, 11°/0°, 3°/8°). Specimens were tested intact and after prostheses implantation with different lordosis distributions. Center of rotation (COR) and range of motion (ROM) were quantified. Six-degree lordosis prostheses (n = 7) showed no difference in flexion-extension ROM, regardless of design (6°/0° or 3°/3°) (p > 0.05). In lateral bending (LB), both designs reduced ROM (p < 0.05). In axial rotation, only the 3°/3° design reduced ROM (p < 0.05). Eleven-degree lordosis prostheses (n = 5) showed no difference in flexion-extension ROM for either design (p > 0.05). LB ROM decreased with distributed lordosis prostheses (3°/8°) (p < 0.05). Overall, L5-S1 range of motion was not markedly influenced by lordosis distribution among the two prosthesis endplates. The ProDisc-L prosthesis design where all lordosis is concentrated in the superior endplate yielded COR locations that were anterior and caudal to intact controls. The prosthesis with lordosis distributed between the two endplates yielded a COR that tended to be closer to intact. Further clinical and biomechanical studies are needed to assess the long-term impact of lordosis angle distribution on the fate of the facet joints.
Moreira, K G; Prates, M V; Andrade, F A C; Silva, L P; Beirão, P S L; Kushmerick, C; Naves, L A; Bloch, C
2010-08-01
Neurotoxicity is a major symptom of envenomation caused by Brazilian coral snake Micrurus frontalis. Due to the small amount of material that can be collected, no neurotoxin has been fully sequenced from this venom. In this work we report six new three-finger like toxins isolated from the venom of the coral snake M. frontalis which we named Frontoxin (FTx) I-VI. Toxins were purified using multiple steps of RP-HPLC. Molecular masses were determined by MALDI-TOF and ESI ion-trap mass spectrometry. The complete amino acid sequence of FTx II, III, IV and V were determined by sequencing of overlapping proteolytic fragments by Edman degradation and by de novo sequencing. The amino acid sequences of FTx I, II, III and VI predict 4 conserved disulphide bonds and structural similarity to previously reported short-chain alpha-neurotoxins. FTx IV and V each contained 10 conserved cysteines and share high similarity with long-chain alpha-neurotoxins. At the frog neuromuscular junction FTx II, III and IV reduced miniature endplate potential amplitudes in a time-and concentration-dependent manner suggesting Frontoxins block nicotinic acetylcholine receptors. Copyright 2010 Elsevier Ltd. All rights reserved.
High frequency of extra-pair paternity in an urban population of Cooper's Hawks
Rosenfield, Robert N.; Sonsthagen, Sarah A.; Stout, William C.; Talbot, Sandra L.
2015-01-01
Raptors exhibit some of the highest rates of intra-pair copulations among birds, perhaps in an attempt by males to reduce the risk of being cuckolded. Indeed, the frequency of extra-pair fertilizations reported in studies of raptors to date is relatively low (0-11.2%). Socially monogamous Cooper's Hawks (Accipiter cooperii) exhibit one of the highest copulation rates among birds, yet there are no published accounts of extra-pair copulations (or paternity). We studied a population of Cooper's Hawks in Milwaukee, Wisconsin, during three breeding seasons (2003, 2004, and 2007), examining the possible effects of age (1 yr old vs. ≥ 2 yr old), adult mass, and brood size on the frequency of extra-pair paternity (EPP). We found that 19.3% of nestlings (N = 27/140) were extra-pair young (EPY), and 34% of all broods (N = 15/44) had at least one EPY. The sires of the EPY in our study were identified for only two broods, suggesting that floater males may have engaged in extra-pair copulations with territorial females. We found that brood size was a good predictor of the occurrence of EPP (EPP) in nests, but adult mass and female age were not. To our knowledge, these possible correlates of the occurrence of EPP in raptors had not previously been investigated. Male Cooper's Hawks provide food for females during the pre-nesting period, and delivery of food is, in contrast to other raptor species, typically followed by copulation. Thus, one possible explanation of the relatively high rates of EPP in our study is that females might accept or even solicit extra-pair copulations from males other than their mates as a means of maximizing energy intake for egg production. Such behavior might be particularly likely in our study area, i.e., a food-rich urban setting with a high breeding density of Cooper's Hawks.
Canadian hepatitis C look-back investigation to detect transmission from an infected general surgeon
Dawar, Meenakshi; Stuart, Tammy L; Sweet, Lamont E; Neatby, Anne M; Abbott, Lewis P; Andonov, Anton P; Wong, Tom; Gervais, Robert; Stirling, Rob
2010-01-01
BACKGROUND: In February 2007, a general surgeon in Charlottetown, Prince Edward Island, tested positive for hepatitis C virus (HCV). The surgeon’s infection onset date could not be determined; however, episodic hepatic enzyme elevations were first detected in November 2004 and again in February 2007. HCV transmission during surgery, alhough rare, has been documented. A phased look-back HCV screening program was conducted to detect HCV transmission from this surgeon to patients who underwent the highest-risk procedures in the three years before his positive test. METHODS: Highest-risk procedures were defined as exposure-prone procedures (EPP) in which exposure to the surgeon’s blood was most likely. EPP patients from January 2004 to February 2007 were identified using hospital and administrative records. Linkages with the provincial notifiable disease for HCV was performed, and death records for deceased EPP patients were reviewed. Eligible patients were invited for screening. RESULTS: Of 6248 patients seen in phase 1, 272 (4.4%) were identified to be EPP. Of the 272 patients, 248 (91.1%) were invited for HCV testing and 24 (8.8%) were deceased. To date, 231 of 248 (93.1%) patients have presented for screening. Two patients (one alive, one deceased) were HCV positive before their EPP. Viral sequence of the surgeon’s isolate is unrelated to the first patient; the second individual has a resolved infection (polymerase chain reaction negative). No new transmission events were identified in the screened patients. The 95% CI of the transmission probability was estimated to be 0 to 0.016. INTERPRETATION: HCV transmission from the surgeon during a 38-month look back was unlikely. In the absence of protocols for investigating HCV transmission from infected health care workers, screening was initially prioritized to the highest-risk patients. The investigation has been satisfactorily terminated based on these results. PMID:21358878
Seismic behavior of outrigger truss-wall shear connections using multiple steel angles
NASA Astrophysics Data System (ADS)
Li, Xian; Wang, Wei; Lü, Henglin; Zhang, Guangchang
2016-06-01
An experimental investigation on the seismic behavior of a type of outrigger truss-reinforced concrete wall shear connection using multiple steel angles is presented. Six large-scale shear connection models, which involved a portion of reinforced concrete wall and a shear tab welded onto a steel endplate with three steel angles, were constructed and tested under combined actions of cyclic axial load and eccentric shear. The effects of embedment lengths of steel angles, wall boundary elements, types of anchor plates, and thicknesses of endplates were investigated. The test results indicate that properly detailed connections exhibit desirable seismic behavior and fail due to the ductile fracture of steel angles. Wall boundary elements provide beneficial confinement to the concrete surrounding steel angles and thus increase the strength and stiffness of connections. Connections using whole anchor plates are prone to suffer concrete pry-out failure while connections with thin endplates have a relatively low strength and fail due to large inelastic deformations of the endplates. The current design equations proposed by Chinese Standard 04G362 and Code GB50011 significantly underestimate the capacities of the connection models. A revised design method to account for the influence of previously mentioned test parameters was developed.
2017-12-06
jsc2017e136939 - At the Cosmonaut Hotel crew quarters in Baikonur, Kazakhstan, the Expedition 54-55 backup crewmembers take a stroll down the Walk of Cosmonauts Dec. 6 to lay flowers in traditional pre-launch ceremonies. From left to right are Jeanette Epp
Transitioning from traditional to green cleaners: an analysis of custodian and manager focus groups.
Simcox, Nancy; Wakai, Sara; Welsh, Loyola; Westinghouse, Carol; Morse, Tim
2012-01-01
Custodians represent one of the largest occupational groups using cleaning agents, and yet their voices are infrequently heard in relation to the introduction of "green" cleaners and the laws regarding environmentally preferable products (EPP). This study reflects worker voices on use and effectiveness of chemicals, as well as incentives and obstacles for green cleaning programs. Sixty-four custodians and staff participated in 10 focus groups. Data were entered into Atlas Ti and the constant comparative method of qualitative data analysis was used to identify themes. Themes included satisfaction in a "well-done" job, more effort required for job, lack of involvement in EPP selection process, EPP's ease of use for workers with English as a Second Language (ESL), misuse of disinfectants, health complaints, and need for training. This study shows that custodians have a voice, and that improved communication and feedback among all the stakeholders are needed to make the transition to green cleaning more effective.
Promiscuity drives sexual selection in a socially monogamous bird.
Webster, Michael S; Tarvin, Keith A; Tuttle, Elaina M; Pruett-Jones, Stephen
2007-09-01
Many socially monogamous species paradoxically show signs of strong sexual selection, suggesting cryptic sources of sexual competition among males. Darwin argued that sexual selection could operate in monogamous systems if breeding sex ratios are biased or if some males attract highly fecund females. Alternatively, sexual selection might result from promiscuous copulations outside the pair bond, although several recent studies have cast doubt on this possibility, in particular by showing that variance in apparent male reproductive success (number of social young) differs little from variance in actual male reproductive success (number of young sired). Our results from a long-term study of the socially monogamous splendid fairy-wren (Malurus splendens) demonstrate that such comparisons are misleading and do not adequately assess the effects of extra-pair paternity (EPP). By partitioning the opportunity for selection and calculating Bateman gradients, we show that EPP has a strong effect on male annual and lifetime fitness, whereas other proposed mechanisms of sexual selection do not. Thus, EPP drives sexual selection in this, and possibly other, socially monogamous species.
NASA Astrophysics Data System (ADS)
Roman, D. R.; Smith, D. A.
2017-12-01
In 2022, the National Geodetic Survey will replace all three NAD 83 reference frames with four new terrestrial reference frames. Each frame will be named after a tectonic plate (North American, Pacific, Caribbean and Mariana) and each will be related to the IGS frame through three Euler Pole parameters (EPPs). This talk will focus on three main areas of error propagation when defining coordinates in these four frames. Those areas are (1) use of the small angle approximation to relate true rotation about an Euler Pole to small rotations about three Cartesian axes (2) The current state of the art in determining the Euler Poles of these four plates and (3) the combination of both IGS Cartesian coordinate uncertainties and EPP uncertainties into coordinate uncertainties in the four new frames. Discussion will also include recent efforts at improving the Euler Poles for these frames and expected dates when errors in the EPPs will cause an unacceptable level of uncertainty in the four new terrestrial reference frames.
The Influence of a Lower Heated Tube on Nucleate Pool Boiling from a Horizontal Tube
1992-06-01
9 C. CONDENSER SECTION .................................... 12 D. COOLING SECTION...lower tube kc thermal conductivity of copper L active boiling tube length Lu non-boiling tube length x Nu Nusselt number p tube outside wall perimeter Pr...teflon endplates. 2. A condenser , assembled using a similar Pyrex-glass tee with aluminum endplates. 3. A reservoir for R- 114 liquid storage. 4. A
Sano, Ichiya; Tanito, Masaki; Uchida, Koji; Katsube, Takashi; Kitagaki, Hajime; Ohira, Akihiro
2015-01-01
To evaluate ocular fluid filtration and endplate positioning in glaucomatous eyes with long-tube glaucoma drainage devices (GDDs) using magnetic resonance imaging (MRI) and the effects of various factors on postoperative intraocular pressure (IOP). This observational case series included 27 consecutive glaucomatous eyes (18 men, 7 women; mean age ± standard error, 63.0±2.0 years) who underwent GDD implantation (n = 8 Ahmed Glaucoma Valves [AGV] and n = 19 Baerveldt Glaucoma Implants [BGI]). Tubes were inserted into the pars plana in 23 eyes and anterior chamber in 4 eyes. Six months postoperatively, high-resolution orbital images were obtained using 3-Tesla MRI with head-array coils, and the filtering bleb volume, bleb height, and distances between the anterior endplate edge and corneal center or limbus or between the endplate and orbital wall were measured. In MR images obtained by three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) sequences, the shunt endplate was identified as low-intensity signal, and the filtering bleb was identified as high-intensity signals above and below the endplate in all eyes. The 6-month-postoperative IOP level was correlated negatively with bleb volume (r = -0.4510, P = 0.0182) and bleb height (r = -0.3954, P = 0.0412). The postoperative IOP was significantly (P = 0.0026) lower in BGI-implanted eyes (12.2±0.7 mmHg) than AGV-implanted eyes (16.7±1.2 mmHg); bleb volume was significantly (P = 0.0093) larger in BGI-implanted eyes (478.8±84.2 mm3) than AGV-implanted eyes (161.1±52.3 mm3). Other parameters did not differ. The presence of intraorbital/periocular accumulation of ocular fluid affects postoperative IOP levels in eyes implanted with long-tube GDDs. Larger filtering blebs after BGI than AGI implantations explain lower postoperative IOP levels achieved with BGI than AGV. The findings will contribute to better understanding of IOP reducing mechanism of long-tube GDDs.
Agricultural management affects evolutionary processes in a migratory songbird
Perlut, N.G.; Freeman-Gallant, C. R.; Strong, A.M.; Donovan, T.M.; Kilpatrick, C.W.; Zalik, N.J.
2008-01-01
Hay harvests have detrimental ecological effects on breeding songbirds, as harvesting results in nest failure. Importantly, whether harvesting also affects evolutionary processes is not known. We explored how hay harvest affected social and genetic mating patterns, and thus, the overall opportunity for sexual selection and evolutionary processes for a ground-nesting songbird, the Savannah sparrow (Passerculus sandwichensis). On an unharvested field, 55% of females were in polygynous associations, and social polygyny was associated with greater rates of extra-pair paternity (EPP). In this treatment, synchrony explained variation in EPP rates, as broods by more synchronous females had more EPP than broods by asynchronous females. In contrast, on a harvested field, simultaneous nest failure caused by haying dramatically decreased the overall incidence of EPP by increasing the occurrence of social monogamy and, apparently, the ability of polygynous males to maintain paternity in their own nests. Despite increased social and genetic monogamy, these haying-mediated changes in mating systems resulted in greater than twofold increase in the opportunity for sexual selection. This effect arose, in part, from a 30% increase in the variance associated with within-pair fertilization success, relative to the unharvested field. This effect was caused by a notable increase (+110%) in variance associated with the quality of social mates following simultaneous nest failure. Because up to 40% of regional habitat is harvested by early June, these data may demonstrate a strong population-level effect on mating systems, sexual selection, and consequently, evolutionary processes. ?? 2008 The Authors.
Fatehi, M; Rowan, E G; Harvey, A L
1995-12-01
Previous studies have shown that homologous phospholipases A2 (PLA2) (Pa-3, Pa-9C, Pa-10F and Pa-11) from the venom of the Australian king brown snake, Pseudechis australis, significantly reduce the resting membrane potentials and quantal contents of endplate potentials recorded from endplate regions of mouse triangularis sterni nerve-muscle preparations. It is not clear whether PLA2 activity is essential for their neuromuscular activities. Therefore, pharmacological studies were carried out to determine whether neuromuscular activity of the toxins changed after treatment with the phospholipase A2 inhibitors 7,7-dimethyl-eicosadienoic acid (DEDA) and manoalide. After incubation of the toxins with manoalide (120 nM), or DEDA (50 microM), no PLA2 activity against 1-stearoyl 2-[3H]arachidonoylglycerophosphocholine was detected. After incubation with manoalide and/or DEDA, the toxins did not depolarize muscle fibre membranes up to 60 min after administration. However, manoalide and DEDA had different influences on the inhibitory effect of these toxic enzymes on acetylcholine release from nerve terminals. Manoalide abolished the inhibitory effect of the toxins on evoked release of acetylcholine. In contrast, DEDA was not able to prevent the reduction of quantal content of endplate potentials induced by the toxins. This study provides evidence that the depolarizing action and the inhibitory effect on release of acetylcholine exerted by these toxic PLA2 from king brown snake are independent phenomena. The evidence for this conclusion was that inhibition of enzymatic activity with an arachidonic acid analogue (DEDA) abolished the depolarizing effect of the toxins but not the effects on the quantal release of acetylcholine from mouse motor nerve terminals. The data suggest that the depolarizing effect of these toxins is probably due to the enzymatic activity. Since manoalide interacts with lysine residues of PLA2 polypeptides, and, as shown here, manoalide prevented inhibition of neurotransmitter release, lysine residues may play an important role in the inhibitory activity of these toxins.
Experimental Investigation of a Wing-in-Ground Effect Craft
Tofa, M. Mobassher; Ahmed, Yasser M.; Jamei, Saeed; Priyanto, Agoes; Rahimuddin
2014-01-01
The aerodynamic characteristics of the wing-in-ground effect (WIG) craft model that has a noble configuration of a compound wing was experimentally investigated and Universiti Teknologi Malaysia (UTM) wind tunnel with and without endplates. Lift and drag forces, pitching moment coefficients, and the centre of pressure were measured with respect to the ground clearance and the wing angle of attack. The ground effect and the existence of the endplates increase the wing lift-to-drag ratio at low ground clearance. The results of this research work show new proposed design of the WIG craft with compound wing and endplates, which can clearly increase the aerodynamic efficiency without compromising the longitudinal stability. The use of WIG craft is representing an ambitious technology that will help in reducing time, effort, and money of the conventional marine transportation in the future. PMID:24701170
Experimental investigation of a wing-in-ground effect craft.
Tofa, M Mobassher; Maimun, Adi; Ahmed, Yasser M; Jamei, Saeed; Priyanto, Agoes; Rahimuddin
2014-01-01
The aerodynamic characteristics of the wing-in-ground effect (WIG) craft model that has a noble configuration of a compound wing was experimentally investigated and Universiti Teknologi Malaysia (UTM) wind tunnel with and without endplates. Lift and drag forces, pitching moment coefficients, and the centre of pressure were measured with respect to the ground clearance and the wing angle of attack. The ground effect and the existence of the endplates increase the wing lift-to-drag ratio at low ground clearance. The results of this research work show new proposed design of the WIG craft with compound wing and endplates, which can clearly increase the aerodynamic efficiency without compromising the longitudinal stability. The use of WIG craft is representing an ambitious technology that will help in reducing time, effort, and money of the conventional marine transportation in the future.
NASA Technical Reports Server (NTRS)
Kaufman, L. G., II; Johnson, C. B.
1977-01-01
Surface pressure distributions are presented for regions where three-dimensional separated flow effects are prominent on swept-wing-elevon-end-plate models of 0 degree, 50 degree, and 70 degree sweepback, and with 0 degree, 10 degree, 20 degree, and 30 degree elevon deflections. Surface-oil-flow photographs and pressure distributions on the flat-plate wing, elevon, and end-plate surfaces are presented for numerous geometric variations, including various spacings between the elevon and the end plate, with and without a tip fin. The data, for a free-stream Mach number of 6 and a wing-root-chord Reynolds number of 20 x 10 to the sixth power, reveal considerably larger regions of elevon induced loads on the adjacent end-plate surface than would be anticipated by using inviscid flow analyses.
Predicting Subsequent Service Potential for Former Army Prisoners
1983-03-25
Esteem Scale, and Hudson’s (1974) Index of Self - Esteem , fou9d significant d_ e.re.e beteen-gr duates-and-non-gj The results of the two studies are...a greater need for autonomy, on the EPPS, and less self - esteem , on the Rosenberg (1965) scale. 400 Table 1 Predicting Graduation/Discharge from...Acceptance (CPI) .588 Education Completed .410 Socialization (CPI) -.445 Highest Pay Grade -.388 Social Presence (CPI) -.443 Marital Status .388 Self - Esteem (Rosenberg
Incident Energy Focused Design and Validation for the Floating Potential Probe
NASA Technical Reports Server (NTRS)
Fincannon, James
2002-01-01
Utilizing the spacecraft shadowing and incident energy analysis capabilities of the NASA Glenn Research Center Power and Propulsion Office's SPACE System Power Analysis for Capability Evaluation) computer code, this paper documents the analyses for various International Space Station (ISS) Floating Potential Probe (EPP) preliminary design options. These options include various solar panel orientations and configurations as well as deployment locations on the ISS. The incident energy for the final selected option is characterized. A good correlation between the predicted data and on-orbit operational telemetry is demonstrated. Minor deviations are postulated to be induced by degradation or sensor drift.
GOES-16 On-Orbit Dual Isolation Performance Characterization Results
NASA Technical Reports Server (NTRS)
Carter, Delano; Clapp, Brian; Early, Derrick; Freesland, Douglas; Chapel, Jim; Bailey, Robert; Krimchansky, Alexander
2016-01-01
The Geostationary Operational Environmental Satellite-R Series (GOES-R) is the first of the next generation geostationary weather satellites. GOES-R successfully launched on November19, 2016 and renamed GOES-16 upon entering geostationary orbit. Subsequently, GOES-16post-launch testing began. This paper presents the GOES-16 Satellite Dynamic Interaction Characterization results for the Earth Pointed Platform (EPP) stowed, referred to as the Reaction Wheel Assembly (RWA) Isolation Only configuration, and deployed, referred to as the Dual Isolation configuration. GOES-R represents a quantum increase in Earth and solar weather observation capabilities, with 4 times the resolution, 5 times the observation rate, and 3 times the number of spectral bands for Earth observations. With the improved resolution, comes the instrument suites increased sensitivity to disturbances over a broad spectrum 0-512Hz. Sources of disturbance include reaction wheels, thruster firings for station keeping and momentum management, gimbal motion, and internal instrument disturbances. To minimize the impact of these disturbances, the baseline design included an EPP, a stiff optical bench to which the two nadir pointed instruments are collocated together with the Guidance Navigation Control (GNC) star trackers and Inertial Measurement Units (IMUs). The EPP is passively isolated from the spacecraft bus with Honeywell D-Strut isolators providing attenuation for frequencies above 5 Hz in all six degrees-of-freedom. To reduce the risk of wheel disturbances impacting performance, a secondary passive isolation system manufactured by Moog CSA Engineering was incorporated under each of the six 160 Nms reaction wheels, tuned to provide attenuation at frequencies above 50 Hz. Integrated wheel and isolator testing was performed on a Kistler table at NASA Goddard Space Flight Center. Pre-launch Satellite Dynamic Interaction Characterization high-fidelity simulations and ground testing were conducted to evaluate jitter performance for two cases: 1) deployed EPP and reaction wheel (Dual Isolation) and 2) EPP hard mounted (RWA Isolation Only) to the spacecraft. A comparison of pre-launch to post-launch Satellite Dynamic Interaction Characterization results are also presented in this paper.
Structural Pituitary Abnormalities Associated With CHARGE Syndrome
Gregory, Louise C.; Gevers, Evelien F.; Baker, Joanne; Kasia, Tessa; Chong, Kling; Josifova, Dragana J.; Caimari, Maria; Bilan, Frederic; McCabe, Mark J.
2013-01-01
Introduction: CHARGE syndrome is a multisystem disorder that, in addition to Kallmann syndrome/isolated hypogonadotrophic hypogonadism, has been associated with anterior pituitary hypoplasia (APH). However, structural abnormalities such as an ectopic posterior pituitary (EPP) have not yet been described in such patients. Objective: The aims of the study were: 1) to describe the association between CHARGE syndrome and a structurally abnormal pituitary gland; and 2) to investigate whether CHD7 variants, which are identified in 65% of CHARGE patients, are common in septo-optic dysplasia /hypopituitarism. Methods: We describe 2 patients with features of CHARGE and EPP. CHD7 was sequenced in these and other patients with septo-optic dysplasia/hypopituitarism. Results: EPP, APH, and GH, TSH, and probable LH/FSH deficiency were present in 1 patient, and EPP and APH with GH, TSH, LH/FSH, and ACTH deficiency were present in another patient, both of whom had features of CHARGE syndrome. Both had variations in CHD7 that were novel and undetected in control cohorts or in the international database of CHARGE patients, but were also present in their unaffected mothers. No CHD7 variants were detected in the patients with septo-optic dysplasia/hypopituitarism without additional CHARGE features. Conclusion: We report a novel association between CHARGE syndrome and structural abnormalities of the pituitary gland in 2 patients with variations in CHD7 that are of unknown significance. However, CHD7 mutations are an uncommon cause of septo-optic dysplasia or hypopituitarism. Our data suggest the need for evaluation of pituitary function/anatomy in patients with CHARGE syndrome. PMID:23526466
NASA Astrophysics Data System (ADS)
Roman, D. R.
2017-12-01
In 2022, the National Geodetic Survey will replace all three NAD 83 reference frames the four new terrestrial reference frames. Each frame will be named after a tectonic plate (North American, Pacific, Caribbean and Mariana) and each will be related to the IGS frame through three Euler Pole parameters (EPPs). This talk will focus on practical application in the Caribbean region. A working group is being re-established for development of the North American region and will likely also result in analysis of the Pacific region as well. Both of these regions are adequately covered with existing CORS sites to model the EPPs. The Mariana region currently lacks sufficient coverage, but a separate project is underway to collect additional information to help in defining EPPs for that region at a later date. The Caribbean region has existing robust coverage through UNAVCO's COCONet and other data sets, but these require further analysis. This discussion will focus on practical examination of Caribbean sites to establish candidates for determining the Caribbean frame EPPs as well as an examination of any remaining velocities that might inform a model of the remaining velocities within that frame (Intra-Frame Velocity Model). NGS has a vested interest in defining such a model to meet obligations to U.S. citizens in Puerto Rico and the U.S. Virgin Islands. Beyond this, NGS aims to collaborate with other countries in the region through efforts with SIRGAS and UN-GGIM-Americas for a more acceptable regional model to serve everyone's needs.
Towards an improved ensemble precipitation forecast: A probabilistic post-processing approach
NASA Astrophysics Data System (ADS)
Khajehei, Sepideh; Moradkhani, Hamid
2017-03-01
Recently, ensemble post-processing (EPP) has become a commonly used approach for reducing the uncertainty in forcing data and hence hydrologic simulation. The procedure was introduced to build ensemble precipitation forecasts based on the statistical relationship between observations and forecasts. More specifically, the approach relies on a transfer function that is developed based on a bivariate joint distribution between the observations and the simulations in the historical period. The transfer function is used to post-process the forecast. In this study, we propose a Bayesian EPP approach based on copula functions (COP-EPP) to improve the reliability of the precipitation ensemble forecast. Evaluation of the copula-based method is carried out by comparing the performance of the generated ensemble precipitation with the outputs from an existing procedure, i.e. mixed type meta-Gaussian distribution. Monthly precipitation from Climate Forecast System Reanalysis (CFS) and gridded observation from Parameter-Elevation Relationships on Independent Slopes Model (PRISM) have been employed to generate the post-processed ensemble precipitation. Deterministic and probabilistic verification frameworks are utilized in order to evaluate the outputs from the proposed technique. Distribution of seasonal precipitation for the generated ensemble from the copula-based technique is compared to the observation and raw forecasts for three sub-basins located in the Western United States. Results show that both techniques are successful in producing reliable and unbiased ensemble forecast, however, the COP-EPP demonstrates considerable improvement in the ensemble forecast in both deterministic and probabilistic verification, in particular in characterizing the extreme events in wet seasons.
Numerical weather prediction model tuning via ensemble prediction system
NASA Astrophysics Data System (ADS)
Jarvinen, H.; Laine, M.; Ollinaho, P.; Solonen, A.; Haario, H.
2011-12-01
This paper discusses a novel approach to tune predictive skill of numerical weather prediction (NWP) models. NWP models contain tunable parameters which appear in parameterizations schemes of sub-grid scale physical processes. Currently, numerical values of these parameters are specified manually. In a recent dual manuscript (QJRMS, revised) we developed a new concept and method for on-line estimation of the NWP model parameters. The EPPES ("Ensemble prediction and parameter estimation system") method requires only minimal changes to the existing operational ensemble prediction infra-structure and it seems very cost-effective because practically no new computations are introduced. The approach provides an algorithmic decision making tool for model parameter optimization in operational NWP. In EPPES, statistical inference about the NWP model tunable parameters is made by (i) generating each member of the ensemble of predictions using different model parameter values, drawn from a proposal distribution, and (ii) feeding-back the relative merits of the parameter values to the proposal distribution, based on evaluation of a suitable likelihood function against verifying observations. In the presentation, the method is first illustrated in low-order numerical tests using a stochastic version of the Lorenz-95 model which effectively emulates the principal features of ensemble prediction systems. The EPPES method correctly detects the unknown and wrongly specified parameters values, and leads to an improved forecast skill. Second, results with an atmospheric general circulation model based ensemble prediction system show that the NWP model tuning capacity of EPPES scales up to realistic models and ensemble prediction systems. Finally, a global top-end NWP model tuning exercise with preliminary results is published.
Improvements in prevalence trend fitting and incidence estimation in EPP 2013
Brown, Tim; Bao, Le; Eaton, Jeffrey W.; Hogan, Daniel R.; Mahy, Mary; Marsh, Kimberly; Mathers, Bradley M.; Puckett, Robert
2014-01-01
Objective: Describe modifications to the latest version of the Joint United Nations Programme on AIDS (UNAIDS) Estimation and Projection Package component of Spectrum (EPP 2013) to improve prevalence fitting and incidence trend estimation in national epidemics and global estimates of HIV burden. Methods: Key changes made under the guidance of the UNAIDS Reference Group on Estimates, Modelling and Projections include: availability of a range of incidence calculation models and guidance for selecting a model; a shift to reporting the Bayesian median instead of the maximum likelihood estimate; procedures for comparison and validation against reported HIV and AIDS data; incorporation of national surveys as an integral part of the fitting and calibration procedure, allowing survey trends to inform the fit; improved antenatal clinic calibration procedures in countries without surveys; adjustment of national antiretroviral therapy reports used in the fitting to include only those aged 15–49 years; better estimates of mortality among people who inject drugs; and enhancements to speed fitting. Results: The revised models in EPP 2013 allow closer fits to observed prevalence trend data and reflect improving understanding of HIV epidemics and associated data. Conclusion: Spectrum and EPP continue to adapt to make better use of the existing data sources, incorporate new sources of information in their fitting and validation procedures, and correct for quantifiable biases in inputs as they are identified and understood. These adaptations provide countries with better calibrated estimates of incidence and prevalence, which increase epidemic understanding and provide a solid base for program and policy planning. PMID:25406747
Eating disorders need more experimental psychopathology.
Jansen, Anita
2016-11-01
Eating disorders are severe and disabling mental disorders. The scientific study of eating disorders has expanded dramatically over the past few decades, and provided significant understanding of eating disorders and their treatments. Those significant advances notwithstanding, there is scant knowledge about key processes that are crucial to clinical improvement. The lack of understanding mechanisms that cause, maintain and change eating disorders, currently is the biggest problem facing the science of eating disorders. It hampers the development of really effective interventions that could be fine-tuned to target the mechanisms of change and, therefore, the development of more effective treatments. It is argued here that the science of eating disorders and eating disorder treatment could benefit tremendously from pure experimental studies into its mechanisms of change, that is, experimental psychopathology (EPP). To illustrate why eating disorders need more EPP research, some key symptoms - restriction of intake, binge eating and body overvaluation - will be discussed. EPP studies challenge some generally accepted views and offer a fresh new look at key symptoms. This will, consequently, better inform eating disorder treatments. Copyright © 2016. Published by Elsevier Ltd.
A fast event preprocessor for the Simbol-X Low-Energy Detector
NASA Astrophysics Data System (ADS)
Schanz, T.; Tenzer, C.; Kendziorra, E.; Santangelo, A.
2008-07-01
The Simbol-X1 Low Energy Detector (LED), a 128 × 128 pixel DEPFET array, will be read out very fast (8000 frames/second). This requires a very fast onboard data preprocessing of the raw data. We present an FPGA based Event Preprocessor (EPP) which can fulfill this requirements. The design is developed in the hardware description language VHDL and can be later ported on an ASIC technology. The EPP performs a pixel related offset correction and can apply different energy thresholds to each pixel of the frame. It also provides a line related common-mode correction to reduce noise that is unavoidably caused by the analog readout chip of the DEPFET. An integrated pattern detector can block all invalid pixel patterns. The EPP has an internal pipeline structure and can perform all operation in realtime (< 2 μs per line of 64 pixel) with a base clock frequency of 100 MHz. It is utilizing a fast median-value detection algorithm for common-mode correction and a new pattern scanning algorithm to select only valid events. Both new algorithms were developed during the last year at our institute.
Optimizing Eco-Efficiency Across the Procurement Portfolio.
Pelton, Rylie E O; Li, Mo; Smith, Timothy M; Lyon, Thomas P
2016-06-07
Manufacturing organizations' environmental impacts are often attributable to processes in the firm's upstream supply chain. Environmentally preferable procurement (EPP) and the establishment of environmental purchasing criteria can potentially reduce these indirect impacts. Life-cycle assessment (LCA) can help identify the purchasing criteria that are most effective in reducing environmental impacts. However, the high costs of LCA and the problems associated with the comparability of results have limited efforts to integrate procurement performance with quantitative organizational environmental performance targets. Moreover, environmental purchasing criteria, when implemented, are often established on a product-by-product basis without consideration of other products in the procurement portfolio. We develop an approach that utilizes streamlined LCA methods, together with linear programming, to determine optimal portfolios of product impact-reduction opportunities under budget constraints. The approach is illustrated through a simulated breakfast cereal manufacturing firm procuring grain, containerboard boxes, plastic packaging, electricity, and industrial cleaning solutions. Results suggest that extending EPP decisions and resources to the portfolio level, recently made feasible through the methods illustrated herein, can provide substantially greater CO2e and water-depletion reductions per dollar spend than a product-by-product approach, creating opportunities for procurement organizations to participate in firm-wide environmental impact reduction targets.
Cunningham, Bryan W; Hu, Nianbin; Zorn, Candace M; McAfee, Paul C
2010-02-01
Using a synthetic vertebral model, the authors quantified the comparative fixation strengths and failure mechanisms of 6 cervical disc arthroplasty devices versus 2 conventional methods of cervical arthrodesis, highlighting biomechanical advantages of prosthetic endplate fixation properties. Eight cervical implant configurations were evaluated in the current investigation: 1) PCM Low Profile; 2) PCM V-Teeth; 3) PCM Modular Flange; 4) PCM Fixed Flange; 5) Prestige LP; 6) Kineflex/C disc; 7) anterior cervical plate + interbody cage; and 8) tricortical iliac crest. All PCM treatments contained a serrated implant surface (0.4 mm). The PCM V-Teeth and Prestige contained 2 additional rows of teeth, which were 1 mm and 2 mm high, respectively. The PCM Modular and Fixed Flanged devices and anterior cervical plate were augmented with 4 vertebral screws. Eight pullout tests were performed for each of the 8 conditions by using a synthetic fixation model consisting of solid rigid polyurethane foam blocks. Biomechanical testing was conducted using an 858 Bionix test system configured with an unconstrained testing platform. Implants were positioned between testing blocks, using a compressive preload of -267 N. Tensile load-to-failure testing was performed at 2.5 mm/second, with quantification of peak load at failure (in Newtons), implant surface area (in square millimeters), and failure mechanisms. The mean loads at failure for the 8 implants were as follows: 257.4 +/- 28.54 for the PCM Low Profile; 308.8 +/- 15.31 for PCM V-Teeth; 496.36 +/- 40.01 for PCM Modular Flange; 528.03+/- 127.8 for PCM Fixed Flange; 306.4 +/- 31.3 for Prestige LP; 286.9 +/- 18.4 for Kineflex/C disc; 635.53 +/- 112.62 for anterior cervical plate + interbody cage; and 161.61 +/- 16.58 for tricortical iliac crest. The anterior plate exhibited the highest load at failure compared with all other treatments (p < 0.05). The PCM Modular and Fixed Flange PCM constructs in which screw fixation was used exhibited higher pullout loads than all other treatments except the anterior plate (p < 0.05). The PCM VTeeth and Prestige and Kineflex/C implants exhibited higher pullout loads than the PCM Low Profile and tricortical iliac crest (p < 0.05). Tricortical iliac crest exhibited the lowest pullout strength, which was different from all other treatments (p < 0.05). The surface area of endplate contact, measuring 300 mm(2) (PCM treatments), 275 mm(2) (Prestige LP), 250 mm(2) (Kineflex/C disc), 180 mm(2) (plate + cage), and 235 mm(2) (tricortical iliac crest), did not correlate with pullout strength (p > 0.05). The PCM, Prestige, and Kineflex constructs, which did not use screw fixation, all failed by direct pullout. Screw fixation devices, including anterior plates, led to test block fracture, and tricortical iliac crest failed by direct pullout. These results demonstrate a continuum of fixation strength based on prosthetic endplate design. Disc arthroplasty constructs implanted using vertebral body screw fixation exhibited the highest pullout strength. Prosthetic endplates containing toothed ridges (>or= 1 mm) or keels placed second in fixation strength, whereas endplates containing serrated edges exhibited the lowest fixation strength. All treatments exhibited greater fixation strength than conventional tricortical iliac crest. The current study offers insights into the benefits of various prosthetic endplate designs, which may potentially improve acute fixation following cervical disc arthroplasty.
Sinis, Nektarios; Horn, Frauke; Genchev, Borislav; Skouras, Emmanouil; Merkel, Daniel; Angelova, Srebrina K; Kaidoglou, Katerina; Michael, Joern; Pavlov, Stoyan; Igelmund, Peter; Schaller, Hans-Eberhard; Irintchev, Andrey; Dunlop, Sarah A; Angelov, Doychin N
2009-10-01
The outcome of peripheral nerve injuries requiring surgical repair is poor. Recent work has suggested that electrical stimulation (ES) of denervated muscles could be beneficial. Here we tested whether ES has a positive influence on functional recovery after injury and surgical repair of the facial nerve. Outcomes at 2 months were compared to animals receiving sham stimulation (SS). Starting on the first day after end-to-end suture (facial-facial anastomosis), electrical stimulation (square 0.1 ms pulses at 5 Hz at an ex tempore established threshold amplitude of between 3.0 and 5.0V) was delivered to the vibrissal muscles for 5 min a day, 3 times a week. Restoration of vibrissal motor performance following ES or SS was evaluated using the video-based motion analysis and correlated with the degree of collateral axonal branching at the lesion site, the number of motor endplates in the target musculature and the quality of their reinnervation, i.e. the degree of mono- versus poly-innervation. Neither protocol reduced collateral branching. ES did not improve functional outcome, but rather reduced the number of innervated motor endplates to approximately one-fifth of normal values and failed to reduce the proportion of poly-innervated motor endplates. We conclude that ES is not beneficial for recovery of whisker function after facial nerve repair in rats.
Evaluation of intervertebral disc cartilaginous endplate structure using magnetic resonance imaging.
Moon, Sung M; Yoder, Jonathon H; Wright, Alexander C; Smith, Lachlan J; Vresilovic, Edward J; Elliott, Dawn M
2013-08-01
The cartilaginous endplate (CEP) is a thin layer of hyaline cartilage positioned between the vertebral endplate and nucleus pulposus (NP) that functions both as a mechanical barrier and as a gateway for nutrient transport into the disc. Despite its critical role in disc nutrition and degeneration, the morphology of the CEP has not been well characterized. The objective of this study was to visualize and report observations of the CEP three-dimensional morphology, and quantify CEP thickness using an MRI FLASH (fast low-angle shot) pulse sequence. MR imaging of ex vivo human cadaveric lumbar spine segments (N = 17) was performed in a 7T MRI scanner with sequence parameters that were selected by utilizing high-resolution T1 mapping, and an analytical MRI signal model to optimize image contrast between CEP and NP. The CEP thickness at five locations along the mid-sagittal AP direction (center, 5 mm, 10 mm off-center towards anterior and posterior) was measured, and analyzed using two-way ANOVA and a post hoc Bonferonni test. For further investigation, six in vivo volunteers were imaged with a similar sequence in a 3T MRI scanner. In addition, decalcified and undecalcified histology was performed, which confirmed that the FLASH sequence successfully detected the CEP. CEP thickness determined by MRI in the mid-sagittal plane across all lumbar disc levels and locations was 0.77 ± 0.24 mm ex vivo. The CEP thickness was not different across disc levels, but was thinner toward the center of the disc. This study demonstrates the potential of MRI FLASH imaging for structural quantification of the CEP geometry, which may be developed as a technique to evaluate changes in the CEP with disc degeneration in future applications.
Cholinergic regulation of the evoked quantal release at frog neuromuscular junction
Nikolsky, Eugeny E; Vyskočil, František; Bukharaeva, Ella A; Samigullin, Dmitry; Magazanik, Lev G
2004-01-01
The effects of cholinergic drugs on the quantal contents of the nerve-evoked endplate currents (EPCs) and the parameters of the time course of quantal release (minimal synaptic latency, main modal value of latency histogram and variability of synaptic latencies) were studied at proximal, central and distal regions of the frog neuromuscular synapse. Acetylcholine (ACh, 5 × 10−4 m), carbachol (CCh, 1 × 10−5 m) or nicotine (5 × 10−6 m) increased the numbers of EPCs with long release latencies mainly in the distal region of the endplate (90–120 μm from the last node of Ranvier), where the synchronization of transmitter release was the most pronounced. The parameters of focally recorded motor nerve action potentials were not changed by either ACh or CCh. The effects of CCh and nicotine on quantal dispersion were reduced substantially by 5 × 10−7 m (+)tubocurarine (TC). The muscarinic agonists, oxotremorine and the propargyl ester of arecaidine, as well as antagonists such as pirenzepine, AF-DX 116 and methoctramine, alone or in combination, did not affect the dispersion of the release. Muscarinic antagonists did not block the dispersion action of CCh. Cholinergic drugs either decreased the quantal content mo (muscarinic agonist, oxotremorine M, and nicotinic antagonist, TC), or decreased mo and dispersed the release (ACh, CCh and nicotine). The effects on mo were not related either to the endplate region or to the initial level of release dispersion. It follows that the mechanisms regulating the amount and the time course of transmitter release are different and that, among other factors, they are altered by presynaptic nicotinic receptors. PMID:15254150
Development of Ultrasound to Measure In-vivo Dynamic Cervical Spine Intervertebral Disc Mechanics
2014-01-01
The deformation between C4 and C6 measured by the US probe was affected by bulging of the IVD and soft tissues during compressive loading as...endplates of the vertebrae and cartilaginous endplate of the discs were added to all segments. Figure 28 Coronal views of the updated C4-T1 FEM (a...the ligaments and soft tissue connections that provide stability to the cervical spine FSUs were added (Figures 30 and 31). For the anterior
Numerical studies of CO2 and brine leakage into a shallow aquifer through an open wellbore
NASA Astrophysics Data System (ADS)
Wang, Jingrui; Hu, Litang; Pan, Lehua; Zhang, Keni
2018-03-01
Industrial-scale geological storage of CO2 in saline aquifers may cause CO2 and brine leakage from abandoned wells into shallow fresh aquifers. This leakage problem involves the flow dynamics in both the wellbore and the storage reservoir. T2Well/ECO2N, a coupled wellbore-reservoir flow simulator, was used to analyze CO2 and brine leakage under different conditions with a hypothetical simulation model in water-CO2-brine systems. Parametric studies on CO2 and brine leakage, including the salinity, excess pore pressure (EPP) and initially dissolved CO2 mass fraction, are conducted to understand the mechanism of CO2 migration. The results show that brine leakage rates increase proportionally with EPP and inversely with the salinity when EPP varies from 0.5 to 1.5 MPa; however, there is no CO2 leakage into the shallow freshwater aquifer if EPP is less than 0.5 MPa. The dissolved CO2 mass fraction shows an important influence on the CO2 plume, as part of the dissolved CO2 becomes a free phase. Scenario simulation shows that the gas lifting effect will significantly increase the brine leakage rate into the shallow freshwater aquifer under the scenario of 3.89% dissolved CO2 mass fraction. The equivalent porous media (EPM) approach used to model the wellbore flow has been evaluated and results show that the EPM approach could either under- or over-estimate brine leakage rates under most scenarios. The discrepancies become more significant if a free CO2 phase evolves. Therefore, a model that can correctly describe the complex flow dynamics in the wellbore is necessary for investigating the leakage problems.
Alagappan, Uma; Pramono, Zacharias A D; Chong, Wei-Sheng
2017-03-01
Erythropoietic protoporphyria (EPP) is a rare inherited disorder of heme biosynthesis caused by decreased activity of the enzyme ferrochelatase (FECH ). The frequency of the hypomorphic c.333-48C allele in a population directly contributes to the prevalence of EPP in the same population. This study sought to identify the molecular basis of EPP in a Chinese patient from Singapore and the c.333-48C allele frequency among the Chinese population in Singapore. FECH gene was screened for mutation in the patient's DNA sample by polymerase chain reaction amplification and DNA sequencing. To validate the identified mutation, the FECH region harboring the mutation was screened in DNA samples from all healthy controls. One patient and 46 ethnically matched healthy controls were included in the study. A novel c.474dupC which leads to a frameshift and premature stop codon was identified in one allele, while the other allele showed to carry c.333-48C and c.337C>T variants in the patient's FECH. The frequency of the c.333-48C hypomorphic allele is 27% among Chinese population in Singapore. c.474dupC in one allele trans to hypomorphic c.333-48C and c.337C>T allele in FECH gene may be the underlying cause of the clinical EPP of the studied patient. The FECH hypomorphic c.333-48C allele frequency in Singapore is lower than the Han Chinese (41.3%) and Japanese (43%) populations but nearly the same as the Southeast Asian (31%) population and higher than the European (2.7-11%) population. © 2016 The International Society of Dermatology.
Grasset, Leslie; Joly, Pierre; Jacqmin-Gadda, Hélène; Letenneur, Luc; Wittwer, Jérôme; Amieva, Hélène; Helmer, Catherine; Dartigues, Jean François
2017-01-01
To analyse the impact of a risk factor on several epidemiological indicators of death and dementia; the example of sport practice is presented. A population of 3670 non-demented subjects living at home and aged 65 and older from the PAQUID study were followed for 22 years. Sport practice was documented at baseline. Dementia (according to DSM-III-R criteria) and death were assessed at each visit. Analyses were performed with an Illness-Death model, providing results on the risks of dementia and death, probabilities and life expectancies. A total of 743 subjects (20.2%) participated in regular sport practice. During the follow-up, the proportion of death was lower in the elderly people practicing sport (EPPS), whereas the proportion of incident dementia cases was the same. The adjusted model showed a decreased risk of dementia (HR = 0.84 (0.72-1.00)) and of death for non-demented subjects (HR = 0.61 (0.51-0.71)) for EPPS but a similar risk of death with dementia in both sport groups. The probability of remaining alive without dementia was higher in EPPS, whereas the probability of dying was lower. The mean lifetime without dementia was 3 years higher for the EPPS, but the mean lifetime with dementia was the same. A preventive measure on a protective factor that is more effective for preventing death than dementia could lead to an increased lifetime without dementia; however, the number of demented cases may remain unchanged, even if the risk of developing dementia is reduced. This dynamic is important to forecast the need for health care and social services for the elderly.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Messner, Mark C.; Sham, Sam; Wang, Yanli
This report summarizes the experiments performed in FY17 on Gr. 91 steels. The testing of Gr. 91 has technical significance because, currently, it is the only approved material for Class A construction that is strongly cyclic softening. Specific FY17 testing includes the following activities for Gr. 91 steel. First, two types of key feature testing have been initiated, including two-bar thermal ratcheting and Simplified Model Testing (SMT). The goal is to qualify the Elastic – Perfectly Plastic (EPP) design methodologies and to support incorporation of these rules for Gr. 91 into the ASME Division 5 Code. The preliminary SMT testmore » results show that Gr. 91 is most damaging when tested with compression hold mode under the SMT creep fatigue testing condition. Two-bar thermal ratcheting test results at a temperature range between 350 to 650o C were compared with the EPP strain limits code case evaluation, and the results show that the EPP strain limits code case is conservative. The material information obtained from these key feature tests can also be used to verify its material model. Second, to provide experimental data in support of the viscoplastic material model development at Argonne National Laboratory, selective tests were performed to evaluate the effect of cyclic softening on strain rate sensitivity and creep rates. The results show the prior cyclic loading history decreases the strain rate sensitivity and increases creep rates. In addition, isothermal cyclic stress-strain curves were generated at six different temperatures, and a nonisothermal thermomechanical testing was also performed to provide data to calibrate the viscoplastic material model.« less
Affairs happen—to whom? A study on extrapair paternity in common nightingales
Wilhelm, Kerstin; Wirth, Jutta; Weiss, Michael; Kipper, Silke
2017-01-01
Abstract Most birds engage in extrapair copulations despite great differences across and within species. Besides cost and benefit considerations of the two sex environmental factors have been found to alter mating strategies within or between populations and/or over time. For socially monogamous species, the main advantage that females might gain from mating with multiple males is probably increasing their offspring’s genetic fitness. Since male (genetic) quality is mostly not directly measurable for female birds, (extrapair) mate choice is based on male secondary traits. In passerines male song is such a sexual ornament indicating male phenotypic and/or genetic quality and song repertoires seem to affect female mate choice in a number of species. Yet their role in extrapair mating behavior is not well understood. In this study, we investigated the proportion of extrapair paternity (EPP) in a population of common nightingales Luscinia megarhynchos. We found that EPP rate was rather high (21.5% of all offspring tested) for a species without sexual dimorphism and high levels of paternal care. Furthermore, the occurrence of EPP was strongly related to the spatial distribution of male territories with males settling in densely occupied areas having higher proportions of extrapair young within their own brood. Also, song repertoire size affected EPP: here larger repertoires of social mates were negatively related to the probability of being cuckolded. When directly comparing repertoires sizes of social and extrapair mates, extrapair mates tended to have larger repertoires. We finally discuss our results as a hint for a flexible mating strategy in nightingales where several factors—including ecological as well as male song features—need to be considered when studying reproductive behavior in monogamous species with complex song. PMID:29492002
END-PLATE ACETYLCHOLINE RECEPTOR: STRUCTURE, MECHANISM, PHARMACOLOGY, AND DISEASE
Sine, Steven M.
2012-01-01
The synapse is a localized neurohumoral contact between a neuron and an effector cell and may be considered the quantum of fast intercellular communication. Analogously, the postsynaptic neurotransmitter receptor may be considered the quantum of fast chemical to electrical transduction. Our understanding of postsynaptic receptors began to develop about a hundred years ago with the demonstration that electrical stimulation of the vagus nerve released acetylcholine and slowed the heart beat. During the past 50 years, advances in understanding postsynaptic receptors increased at a rapid pace, owing largely to studies of the acetylcholine receptor (AChR) at the motor endplate. The endplate AChR belongs to a large superfamily of neurotransmitter receptors, called Cys-loop receptors, and has served as an exemplar receptor for probing fundamental structures and mechanisms that underlie fast synaptic transmission in the central and peripheral nervous systems. Recent studies provide an increasingly detailed picture of the structure of the AChR and the symphony of molecular motions that underpin its remarkably fast and efficient chemoelectrical transduction. PMID:22811427
Zhang, Zhenjun; Fogel, Guy R; Liao, Zhenhua; Sun, Yitao; Liu, Weiqiang
2018-06-01
Lateral lumbar interbody fusion using cage supplemented with fixation has been used widely in the treatment of lumbar disease. A combined fixation (CF) of lateral plate and spinous process plate may provide multiplanar stability similar to that of bilateral pedicle screws (BPS) and may reduce morbidity. The biomechanical influence of the CF on cage subsidence and facet joint stress has not been well described. The aim of this study was to compare biomechanics of various fixation options and to verify biomechanical effects of the CF. The surgical finite element models with various fixation options were constructed based on computed tomography images. The lateral plate and posterior spinous process plate were applied (CF). The 6 motion modes were simulated. Range of motion (ROM), cage stress, endplate stress, and facet joint stress were compared. For the CF model, ROM, cage stress, and endplate stress were the minimum in almost all motion modes. Compared with BPS, the CF reduced ROM, cage stress, and endplate stress in all motion modes. The ROM was reduced by more than 10% in all motion modes except for flexion; cage stress and endplate stress were reduced more than 10% in all motion modes except for rotation-left. After interbody fusion, facet joint stress was reduced substantially compared with the intact conditions in all motion modes except for flexion. The combined plate fixation may offer an alternative to BPS fixation in lateral lumbar interbody fusion. Copyright © 2018 Elsevier Inc. All rights reserved.
Gray, W P; Keohane, C; Kirwan, W O
1997-10-01
The motor nerve transplantation (MNT) technique is used to transfer an intact nerve into a denervated muscle by harvesting a neurovascular pedicle of muscle containing motor endplates from the motor endplate zone of a donor muscle and implanting it into a denervated muscle. Thirty-six adult New Zealand White rabbits underwent reinnervation of the left long peroneal (LP) muscle (fast twitch) with a motor nerve graft from the soleus muscle (slow twitch). The right LP muscle served as a control. Reinnervation was assessed using microstimulatory single-fiber electromyography (SFEMG), alterations in muscle fiber typing and grouping, and isometric response curves. Neurofilament antibody was used for axon staining. The neurofilament studies provided direct evidence of nerve growth from the motor nerve graft into the adjacent denervated muscle. Median motor endplate jitter was 13 microsec preoperatively, and 26 microsec at 2 months, 29.5 microsec at 4 months, and 14 microsec at 6 months postoperatively (p < 0.001). Isometric tetanic tension studies showed a progressive functional recovery in the reinnervated muscle over 6 months. There was no histological evidence of aberrant reinnervation from any source outside the nerve pedicle. Isometric twitch responses and adenosine triphosphatase studies confirmed the conversion of the reinnervated LP muscle to a slow-type muscle. Acetylcholinesterase studies confirmed the presence of functioning motor endplates beneath the insertion of the motor nerve graft. It is concluded that the MNT technique achieves motor reinnervation by growth of new nerve fibers across the pedicle graft into the recipient muscle.
Brown, Stephen H M; Gregory, Diane E; McGill, Stuart M
2008-01-01
In a healthy spine, end-plate fractures occur from excessive pressurization of the intervening nucleus. Younger spines are most susceptible to such type of injury due to the highly hydraulic nature of their intervertebral discs. The purpose of this paper was to confirm this fracture mechanism of the healthy spine through the pressurization of the nucleus in the absence of external compressive loading. Sixteen functional porcine spine units were dissected and both injection and pressure transducer needles were inserted into the nucleus of the intervertebral disc. Hydraulic fluid was rapidly injected into the nucleus until failure occurred. Peak pressure and rate of pressure development were monitored. Spine units were dissected to determine the type and location of fracture. Fifteen of the 16 spine units fractured (the remaining unit had a degenerated disc). Of the 15 fractures, 13 occurred at the posterior margin of the end-plate along the lines of the growth plates. A slightly exponential relationship was found between peak pressure and its rate of development (R(2) = 0.544). Also, in each of the growth-plate fractured specimens, nuclear material was forcefully emitted, during fracture, from the intervertebral disc into the vertebral foramen. The posterior end-plate fractures produced here are similar to those often seen in young adult humans. This provides insight into a mechanism of fracture development through pressurization of the nucleus that might be seen in older adolescents and younger adults during athletic events or mild trauma.
Observations on the elimination of polyneuronal innervation in developing mammalian skeletal muscle.
O'Brien, R A; Ostberg, A J; Vrbová, G
1978-01-01
1. The mechanism responsible for the elimination of polyneuronal innervation in developing rat soleus muscles was studied electrophysiologically and histologically. 2. Initially all the axons contacting a single end-plate have simple bulbous terminals. As elimination proceeds one axon develops terminal branches while the other terminals remain bulbous and may be seen in contact with, or a short distance away from, the end-plate. It is suggested that the branched terminal remains in contact with the muscle fibre while the other terminals withdraw. 3. At a time when polyneuronal innervation can no longer be detected electrophysiologically, the histological technique still shows the presence of end-plates contacted by more than one nerve terminal. 4. The effect of activity on the disappearance of polyneuronal innervation was examined. Activity was increased by electrical stimulation of the right sciatic nerve. This procedure also produced reflex activity in the contralateral limb. In both cases polyneuronal innervation was eliminated more rapidly in the active muscles. 5. The finding that proteolytic enzymes are released from muscles treated with acetylcholine (ACh), and the observation of the more rapid elimination of supernumerary terminals at the end-plates of active muscles, lead to the suggestion that superfluous nerve-muscle contacts are removed by the proteolytic enzymes in response to neuromuscular activity. The selective stabilization of only one of the terminals is discussed in the light of these results. Images Plate 1 Plate 2 PMID:722562
Celebrating the 21st anniversary of empowerment evaluation with our critical friends.
Fetterman, David; Wandersman, Abraham
2017-08-01
This special topic edition of E&PP presents the insights of luminaries in the field who have helped shape empowerment evaluation with their critiques, concerns, and congratulations. We celebrate their contributions to empowerment evaluation. This special topic edition of E&PP presents their comments about an evaluation approach that, according to president Stewart Donaldson, has "gone viral" across the globe (Donaldson, 2015). To set the stage for these critical friends' comments, additional context for their discussion is provided. In addition, this special topic edition concludes with a brief comment on their thoughts. Copyright © 2016 Elsevier Ltd. All rights reserved.
CAD-Based Shielding Analysis for ITER Port Diagnostics
NASA Astrophysics Data System (ADS)
Serikov, Arkady; Fischer, Ulrich; Anthoine, David; Bertalot, Luciano; De Bock, Maartin; O'Connor, Richard; Juarez, Rafael; Krasilnikov, Vitaly
2017-09-01
Radiation shielding analysis conducted in support of design development of the contemporary diagnostic systems integrated inside the ITER ports is relied on the use of CAD models. This paper presents the CAD-based MCNP Monte Carlo radiation transport and activation analyses for the Diagnostic Upper and Equatorial Port Plugs (UPP #3 and EPP #8, #17). The creation process of the complicated 3D MCNP models of the diagnostics systems was substantially accelerated by application of the CAD-to-MCNP converter programs MCAM and McCad. High performance computing resources of the Helios supercomputer allowed to speed-up the MCNP parallel transport calculations with the MPI/OpenMP interface. The found shielding solutions could be universal, reducing ports R&D costs. The shield block behind the Tritium and Deposit Monitor (TDM) optical box was added to study its influence on Shut-Down Dose Rate (SDDR) in Port Interspace (PI) of EPP#17. Influence of neutron streaming along the Lost Alpha Monitor (LAM) on the neutron energy spectra calculated in the Tangential Neutron Spectrometer (TNS) of EPP#8. For the UPP#3 with Charge eXchange Recombination Spectroscopy (CXRS-core), an excessive neutron streaming along the CXRS shutter, which should be prevented in further design iteration.
Small area estimation of proportions with different levels of auxiliary data.
Chandra, Hukum; Kumar, Sushil; Aditya, Kaustav
2018-03-01
Binary data are often of interest in many small areas of applications. The use of standard small area estimation methods based on linear mixed models becomes problematic for such data. An empirical plug-in predictor (EPP) under a unit-level generalized linear mixed model with logit link function is often used for the estimation of a small area proportion. However, this EPP requires the availability of unit-level population information for auxiliary data that may not be always accessible. As a consequence, in many practical situations, this EPP approach cannot be applied. Based on the level of auxiliary information available, different small area predictors for estimation of proportions are proposed. Analytic and bootstrap approaches to estimating the mean squared error of the proposed small area predictors are also developed. Monte Carlo simulations based on both simulated and real data show that the proposed small area predictors work well for generating the small area estimates of proportions and represent a practical alternative to the above approach. The developed predictor is applied to generate estimates of the proportions of indebted farm households at district-level using debt investment survey data from India. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Crawford, Charles H; Glassman, Steven D; Gum, Jeffrey L; Carreon, Leah Y
2017-01-01
Advancements in the understanding of adult spinal deformity have led to a greater awareness of the role of the pelvis in maintaining sagittal balance and alignment. Pelvic incidence has emerged as a key radiographic measure and should closely match lumbar lordosis. As proper measurement of the pelvic incidence requires accurate identification of the S-1 endplate, lumbosacral transitional anatomy may lead to errors. The purpose of this study is to demonstrate how lumbosacral transitional anatomy may lead to errors in the measurement of pelvic parameters. The current case highlights one of the potential complications that can be avoided with awareness. The authors report the case of a 61-year-old man who had undergone prior lumbar surgeries and then presented with symptomatic lumbar stenosis and sagittal malalignment. Radiographs showed a lumbarized S-1. Prior numbering of the segments in previous surgical and radiology reports led to a pelvic incidence calculation of 61°. Corrected numbering of the segments using the lumbarized S-1 endplate led to a pelvic incidence calculation of 48°. Without recognition of the lumbosacral anatomy, overcorrection of the lumbar lordosis might have led to negative sagittal balance and the propensity to develop proximal junction failure. This case illustrates that improper identification of lumbosacral transitional anatomy may lead to errors that could affect clinical outcome. Awareness of this potential error may help improve patient outcomes.
A murine model of elastase- and cigarette smoke-induced emphysema.
Rodrigues, Rubia; Olivo, Clarice Rosa; Lourenço, Juliana Dias; Riane, Alyne; Cervilha, Daniela Aparecida de Brito; Ito, Juliana Tiyaki; Martins, Milton de Arruda; Lopes, Fernanda Degobbi Tenório Quirino Dos Santos
2017-01-01
To describe a murine model of emphysema induced by a combination of exposure to cigarette smoke (CS) and instillation of porcine pancreatic elastase (PPE). A total of 38 C57BL/6 mice were randomly divided into four groups: control (one intranasal instillation of 0.9% saline solution); PPE (two intranasal instillations of PPE); CS (CS exposure for 60 days); and CS + PPE (two intranasal instillations of PPE + CS exposure for 60 days). At the end of the experimental protocol, all animals were anesthetized and tracheostomized for calculation of respiratory mechanics parameters. Subsequently, all animals were euthanized and their lungs were removed for measurement of the mean linear intercept (Lm) and determination of the numbers of cells that were immunoreactive to macrophage (MAC)-2 antigen, matrix metalloproteinase (MMP)-12, and glycosylated 91-kDa glycoprotein (gp91phox) in the distal lung parenchyma and peribronchial region. Although there were no differences among the four groups regarding the respiratory mechanics parameters assessed, there was an increase in the Lm in the CS + PPE group. The numbers of MAC-2-positive cells in the peribronchial region and distal lung parenchyma were higher in the CS + PPE group than in the other groups, as were the numbers of cells that were positive for MMP-12 and gp91phox, although only in the distal lung parenchyma. Our model of emphysema induced by a combination of PPE instillation and CS exposure results in a significant degree of parenchymal destruction in a shorter time frame than that employed in other models of CS-induced emphysema, reinforcing the importance of protease-antiprotease imbalance and oxidant-antioxidant imbalance in the pathogenesis of emphysema. Descrever um modelo murino de enfisema induzido por exposição a fumaça de cigarro (FC) e instilação de elastase pancreática porcina (EPP). Trinta e oito camundongos C57BL/6 foram aleatoriamente divididos em quatro grupos: controle (uma instilação intranasal de solução salina a 0,9%); EPP (duas instilações intranasais de EPP); FC (exposição a FC durante 60 dias) e FC + EPP (duas instilações intranasais de EPP + exposição a FC durante 60 dias). No fim do protocolo experimental, todos os animais foram anestesiados e traqueostomizados para o cálculo de parâmetros de mecânica respiratória. Em seguida, todos os animais foram sacrificados e seus pulmões foram removidos para a medição da intercepção linear média (Lm) e a determinação do número de células imunorreativas a antígeno macrofágico (MAC)-2, metaloproteinase da matriz (MMP)-12 e glicoproteína glicosilada de 91 kDa (gp91phox) no parênquima pulmonar distal e na região peribrônquica. Embora não tenha havido diferenças entre os quatro grupos quanto aos parâmetros de mecânica respiratória avaliados, houve aumento da Lm no grupo FC + EPP. O número de células positivas para MAC-2 na região peribrônquica e no parênquima pulmonar distal foi maior no grupo FC + EPP do que nos outros grupos, assim como o foi o número de células positivas para MMP-12 e gp91phox, porém somente no parênquima pulmonar distal. Nosso modelo de enfisema induzido por instilação de EPP e exposição a FC resulta em um grau significativo de destruição parenquimatosa em um período de tempo menor que o empregado em outros modelos de enfisema induzido por FC, o que reforça a importância do desequilíbrio entre proteases e antiproteases e entre oxidantes e antioxidantes na patogênese do enfisema.
Guidelines for pre-clinical animal and cellular models of MuSK-myasthenia gravis.
Phillips, W D; Christadoss, P; Losen, M; Punga, A R; Shigemoto, K; Verschuuren, J; Vincent, A
2015-08-01
Muscle-specific tyrosine kinase (MuSK) autoantibodies are the hallmark of a form of myasthenia gravis (MG) that can challenge the neurologist and the experimentalist. The clinical disease can be difficult to treat effectively. MuSK autoantibodies affect the neuromuscular junction in several ways. When added to muscle cells in culture, MuSK antibodies disperse acetylcholine receptor clusters. Experimental animals actively immunized with MuSK develop MuSK autoantibodies and muscle weakness. Weakness is associated with reduced postsynaptic acetylcholine receptor numbers, reduced amplitudes of miniature endplate potentials and endplate potentials, and failure of neuromuscular transmission. Similar impairments have been found in mice injected with IgG from MG patients positive for MuSK autoantibody (MuSK-MG). The active and passive models have begun to reveal the mechanisms by which MuSK antibodies disrupt synaptic function at the neuromuscular junction, and should be valuable in developing therapies for MuSK-MG. However, translation into new and improved treatments for patients requires procedures that are not too cumbersome but suitable for examining different aspects of MuSK function and the effects of potential therapies. Study design, conduct and analysis should be carefully considered and transparently reported. Here we review what has been learnt from animal and culture models of MuSK-MG, and offer guidelines for experimental design and conduct of studies, including sample size determination, randomization, outcome parameters and precautions for objective data analysis. These principles may also be relevant to the increasing number of other antibody-mediated diseases that are now recognized. Copyright © 2014 Elsevier Inc. All rights reserved.
Powley, Terry L.; Mittal, Ravinder K.; Baronowsky, Elizabeth A.; Hudson, Cherie N.; Martin, Felecia N.; McAdams, Jennifer L.; Mason, Jacqueline K.; Phillips, Robert J.
2013-01-01
Little is known about the architecture of the vagal motor units that control esophageal striated muscle, in spite of the fact that these units are necessary, and responsible, for peristalsis. The present experiment was designed to characterize the motor neuron projection fields and terminal arbors forming esophageal motor units. Nucleus ambiguus compact formation neurons of the rat were labeled by bilateral intracranial injections of the anterograde tracer dextran biotin. After tracer transport, thoracic and abdominal esophagi were removed and prepared as whole mounts of muscle wall without mucosa or submucosa. Labeled terminal arbors of individual vagal motor neurons (n = 78) in the esophageal wall were inventoried, digitized and analyzed morphometrically. The size of individual vagal motor units innervating striated muscle, throughout thoracic and abdominal esophagus, averaged 52 endplates per motor neuron, a value indicative of fine motor control. A majority (77%) of the motor terminal arbors also issued one or more collateral branches that contacted neurons, including nitric oxide synthase-positive neurons, of local myenteric ganglia. Individual motor neuron terminal arbors co-innervated, or supplied endplates in tandem to, both longitudinal and circular muscle fibers in roughly similar proportions (i.e., two endplates to longitudinal for every three endplates to circular fibers). Both the observation that vagal motor unit collaterals project to myenteric ganglia and the fact that individual motor units co-innervate longitudinal and circular muscle layers are consistent with the hypothesis that elements contributing to peristaltic programming inhere, or are “hardwired,” in the peripheral architecture of esophageal motor units. PMID:24044976
Powley, Terry L; Mittal, Ravinder K; Baronowsky, Elizabeth A; Hudson, Cherie N; Martin, Felecia N; McAdams, Jennifer L; Mason, Jacqueline K; Phillips, Robert J
2013-12-01
Little is known about the architecture of the vagal motor units that control esophageal striated muscle, in spite of the fact that these units are necessary, and responsible, for peristalsis. The present experiment was designed to characterize the motor neuron projection fields and terminal arbors forming esophageal motor units. Nucleus ambiguus compact formation neurons of the rat were labeled by bilateral intracranial injections of the anterograde tracer dextran biotin. After tracer transport, thoracic and abdominal esophagi were removed and prepared as whole mounts of muscle wall without mucosa or submucosa. Labeled terminal arbors of individual vagal motor neurons (n=78) in the esophageal wall were inventoried, digitized and analyzed morphometrically. The size of individual vagal motor units innervating striated muscle, throughout thoracic and abdominal esophagus, averaged 52 endplates per motor neuron, a value indicative of fine motor control. A majority (77%) of the motor terminal arbors also issued one or more collateral branches that contacted neurons, including nitric oxide synthase-positive neurons, of local myenteric ganglia. Individual motor neuron terminal arbors co-innervated, or supplied endplates in tandem to, both longitudinal and circular muscle fibers in roughly similar proportions (i.e., two endplates to longitudinal for every three endplates to circular fibers). Both the observation that vagal motor unit collaterals project to myenteric ganglia and the fact that individual motor units co-innervate longitudinal and circular muscle layers are consistent with the hypothesis that elements contributing to peristaltic programming inhere, or are "hardwired," in the peripheral architecture of esophageal motor units. © 2013.
Castañeda-Villa, N; Jiménez-González, A; Ortiz-Posadas, M R
2015-08-01
Since 1974, the Bachelor of Biomedical Engineering Program (BBME) is offered at Universidad Autónoma Metropolitana-Iztapalapa, in Mexico City. By design, it must be completed in four years (12 trimesters) and, in the latter three, the senior students work on a BME project, which is done by completing three modules: Project Seminar (PS), Project on BME I and Project on BME II. In the PS module, the student must find a problem of interest in the BME field and suggest a solution through the development of an Engineering Project Proposal (EPP). Currently, the module is being taught by two faculty members of the BBME, who instruct students on how to develop their EPPs and evaluate their progress by reviewing a number of EPPs during the trimester. This generates a huge workload for the module instructors, which makes it necessary to involve more faculty members trimester-to-trimester (i.e. every 12 weeks) and, therefore, to create a set of systematic guidelines that ease the evaluation process for new instructors. Hence, the purpose of this paper is to present an assessment strategy (in the form of an assessment matrix) for the PS module as well as some preliminary results after two trimesters of its implementation.
Pina, Gisela de M. S.; Lia, Erica N.; Berretta, Andresa A.; Nascimento, Andresa P.; Torres, Elina C.; Buszinski, Andrei F. M.; de Campos, Tatiana A.; Martins, Vicente de P.
2017-01-01
Our hypothesis tested the efficacy and safety of a mucoadhesive oral gel formulation of Brazilian propolis extract compared to miconazole oral gel for the treatment of denture stomatitis due to Candida spp. infection in older adults. Forty patients were randomly allocated in a noninferiority clinical trial into two groups. The control group (MIC) received 20 mg/g miconazole oral gel and the study group (PROP) received mucoadhesive formulation containing standardized extract of 2% (20 mg/g) propolis (EPP-AF®) during 14 days. Patients were examined on days 1, 7, and 14. The Newton's score was used to classify the severity of denture stomatitis. The colony forming unity count (CFU/mL) was quantified and identified (CHROMagar Candida®) before and after the treatment. Baseline characteristics did not differ between groups. Both treatments reduced Newton's score (P < 0.0001), indicating a clinical improvement of the symptoms of candidiasis with a clinical cure rate of 70%. The microbiological cure with significant reduction in fungal burden on T14 was 70% in the miconazole group and 25% in the EPP-AF group. The EPP-AF appears to be noninferior to miconazole considering the clinical cure rate and could be recommended as an alternative treatment in older patients. PMID:28396692
van Nierop, M; van Os, J; Gunther, N; van Zelst, C; de Graaf, R; ten Have, M; van Dorsselaer, S; Bak, M; Myin-Germeys, I; van Winkel, R
2014-06-01
Based on theoretical considerations and animal studies, mediation of 'social defeat' (SD) in the association between childhood trauma (CT) and psychosis was investigated. Trained interviewers administered a structured interview assessing CT, psychotic experiences and other psychopathology in 6646 participants in the second Netherlands Mental Health Survey and Incidence Study (NEMESIS-2). Childhood trauma was associated with psychotic experiences making up the extended psychosis phenotype (EPP), as well as with a diagnosis of psychotic disorder (PD). Similarly, CT was associated with a priori selected items indexing SD (discouraged, hopeless, worthless, loss of self-confidence, low self-esteem, better off dead, suicidal thoughts) and with a measure of affective dysregulation (AD), which in turn were also associated with psychosis. While SD and AD individually acted as mediators in the association between CT and EPP, only SD acted as a mediator in the association between CT and PD. Cannabis use did not mediate the association between CT and EPP or PD. The present results suggest a developmental model implicating SD as an important mediator in the link between childhood adverse experiences and later development of psychotic experiences. The combined mediation by SD and AD is compatible with an 'affective pathway' to early psychosis. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Matthews-Bellinger, J; Salpeter, M M
1978-01-01
1. The distribution of acetylcholine receptors (AChR) at frog cutaneous pectoris neuromuscular junctions was studied quantitatively using [1125]alpha-bungarotoxin (alpha-BTX) labelling and EM autoradiography. 2. We found that, as in mouse end-plates, the AChR is localized uniformly along the thickened post-junctional membrane. In the frog muscle this specialized membrane constitutes approximately the top 50% of the junctional folds. 3. The receptor site density is approximately 26,000 +/- 6000 sites/micrometer2 on the thickened post-junctional membrane and falls sharply to approximately 50 sites/micrometer2 within 15 micrometer from the axon terminal. 4. alpha-BTX site density on the presynaptic axonal membrane was directly determined to be at most 5% of the value on the thickened post-junctional membrane. 5. The high post junctional AChR site density leads us to conclude that: (a) each quantum of ACh needs to spread only over a very small post-junctional area (to be called the 'critical area') before it encounters as many AChR (plus AchE) sites as there are ACh molecules in the quantum (for a packet of 10(4) ACh molecules this critical area is approximately 0.3 micrometer2), (b) the average concentration of ACh prevailing in the cleft over this critical area during a quantal response will be approximately 10(-3)M (independent of the size of the quantal packet), and (c) since 10(-3)M-ACh is large compared to any estimates of the dissociation constant Kd for ACh binding to the AChR, the ACh will essentially saturate the AChR within the critical area (provided the ACh binding rate is sufficiently faster than the ACh spreading rate). 6. The total receptive surface for a frog end-plate is calculated to be approximately 1500 micrometer2, and therefore an end-plate potential resulting from 300 quanta will be due to the activation of less than 10% of the total receptive area. 7. Free diffusion would allow each small post-junctional critical area to be reached in less than 15 musec. Therefore, either the recorded rise time of the miniature end-plate is not predominantly a function of ACh diffusion time, or, as suggested by Gage & McBurney (1975), the net rate of movement of ACh in the cleft is much slower than indicated by the free diffusion constant. Images Fig. 1a and b Fig. 2 Figs. 3, 5 Fig. 4 PMID:307600
NASA Technical Reports Server (NTRS)
Sivells, James C; Deters, Owen J
1946-01-01
A method is presented for determining the jet-boundary and plan-form corrections necessary for application to test data for a partial-span model with a reflection plane, an end plate, or no end plate in a closed circular wind tunnel. Examples are worked out for a partial-span model with each of the three end conditions in the Langley 19-foot pressure tunnel and the corrections are applied to measured values of lift, drag, pitching-moment, rolling-moment, and yawing-moment coefficients.
Workforce and graduate school outcomes of NOAA's Educational Partnership Program
NASA Astrophysics Data System (ADS)
Christenson, T.; Kaplan, M.
2017-12-01
Underrepresented groups, including Black, Hispanic, Native American, Alaska Native, Native Hawaiian and Pacific Island professionals remain underrepresented in STEM fields generally, and in the ocean and atmospheric sciences specifically. NOAA has tried to address this disparity through a number of initiatives under the Educational Partnership Program with Minority Serving Institutions (EPP MSI) which currently has two components: four Cooperative Science Centers (CSCs) aligned with NOAA's mission areas; and an Undergraduate Scholarship Program (USP), both established in 2001. In order to determine the outcomes for the program participants and the impacts of these programs on degree completions and on the workforce, the EPP MSI undertook a multi-pronged effort to identify career and education achievements for 80% of the approximately 1750 EPP MSI alumni, 75% of whom are from underrepresented groups. This was accomplished through 1) searching online resources (e.g. professional web pages, LinkedIn, etc.), 2) personal communication with program-associated faculty, 3) National Student Clearinghouse, 4) a survey of former scholars conducted by Insight Policy Research, and 5) self-reporting though NOAA's Voluntary Alumni Update System. Results show that 60% of CSC alumni currently hold an advanced degree in a STEM field with another 8% currently working toward one. 66% of EPP Undergraduate Scholars go to graduate school. 72% of CSC and USP alumni are currently employed in or pursuing a graduate degree in a NOAA-related* field. More than 70 CSC graduates currently work for NOAA as contractors or federal employees while more than 240 work for other government agencies. More than 400 are employed in the private sector. Of more than 225 PhD graduates, 66 have completed or currently hold post-doctoral positions in NOAA mission fields; 71 have held faculty positions at major universities. However, one challenge is retaining diverse STEM talent within the Geosciences in light of the lure of lucrative jobs in other STEM fields and ensuring robust outcomes beyond degree completions.
Kalina, Maria A; Kalina-Faska, Barbara; Gruszczyńska, Katarzyna; Baron, Jan; Małecka-Tendera, Ewa
2012-01-01
The purpose of this study is to assess the relationship between magnetic resonance images (MRI) of the hypothalamic-pituitary (H-P) region and response to recombinant human growth hormone (rhGH) treatment in short children with growth hormone deficiency, basing on changes of auxologic parameters, as well as to answer the question if MRI may serve for selecting and monitoring the rhGH responders. The study group comprised 85 children treated with rhGH, aged 7.3-18.7 years, followed for the mean period of 3.2 years (range, 2.1-9.5 years). Auxologic parameters (height deficit hSDS, deviation from the mid-parental height hSDS-mpSDS, bone delay index bone age/chronological age ratio (BA/CA)) were assessed before, during and at the end of rhGH treatment; growth velocity was calculated before and during rhGH therapy. Parameters were correlated with the MRI of the H-P region. Structural anomalies of the H-P region were found in 22 (25.9%) children: empty sella syndrome (ESS) in 12 (14.1%) patients, ectopic posterior pituitary (EPP) in ten (11.8%). Patients' height deficit and their deviation from parental height before rhGH therapy was significantly greater in the EPP group (median hSDS = -3.8; hSDS-mpSDS = -2.5), bone age delay was the greatest in the ESS group (median BA/CA = 0.69), after therapy - in the EPP group (median BA/CA = 0.82). Growth velocity improved in the first year of the rhGH therapy in all groups; however, the most significant acceleration was observed in the EPP group (median delta hSDS = 0.9), then stabilised and was comparable in all groups. MRI may be helpful in predicting response to the rhGH treatment, providing midline abnormalities are taken into account.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Allen, Aaron M.; Den, Robert; Department of Radiation Oncology, Brigham and Women's Hospital, Boston, MA
2007-08-01
Purpose: Extrapleural pneumonectomy (EPP) is an effective treatment of malignant pleural mesothelioma. We compared the outcomes after moderate-dose hemithoracic radiotherapy (MDRT) and high-dose hemithoracic RT (HDRT) after EPP for malignant pleural mesothelioma. Methods and Materials: Between July 1994 and April 2004, 39 patients underwent EPP and adjuvant RT at Dana-Farber Cancer Institute/Brigham and Women's Hospital. Between 1994 and 2002, MDRT, including 30 Gy to the hemithorax, 40 Gy to the mediastinum, and boosts to positive margins or nodes to 54 Gy, was given, generally with concurrent chemotherapy. In 2003, HDRT to 54 Gy with a matched photon/electron technique was given,more » with sequential chemotherapy. Results: A total of 39 patients underwent RT after EPP. The median age was 59 years (range, 44-77). The histologic type was epithelial in 25 patients (64%) and mixed or sarcomatoid in 14 patients (36%). Of the 39 patients, 24 underwent MDRT and 15 (39%) HDRT. The median follow-up was 23 months (range, 6-71). The median overall survival was 19 months (95% confidence interval, 14-24). The median time to distant failure (DF) and local failure (LF) was 20 months (95% confidence interval, 14-26) and 26 months (95% confidence interval, 16-36), respectively. On univariate and multivariate analyses, only a mixed histologic type was predictive of inferior DF (p <0.006) and overall survival (p <0.004). The RT technique was not predictive of LF, DF, or overall survival. The LF rate was 50% (12 of 24) after MDRT and 27% (4 of 15) after HDRT (p = NS). Four patients who had undergone HDRT were alive and without evidence of disease at the last follow-up. Conclusions: High-dose hemithoracic RT appears to limit in-field LF compared with MDRT. However, DF remains a significant challenge, with one-half of our patients experiencing DF.« less
Cleaning Products Pilot Project
This 1997 case study documents a three-year effort to identify and compare environmentally preferable commercial cleaning products and to implement the Environmentally Preferable Purchasing Program (EPP).
Vohs, Jenifer L; Leonhardt, Bethany L; James, Alison V; Francis, Michael M; Breier, Alan; Mehdiyoun, Nikki; Visco, Andrew C; Lysaker, Paul H
2018-05-01
Poor insight impedes treatment in early phase psychosis (EPP). This manuscript outlines preliminary findings of an investigation of the novel metacognitively oriented integrative psychotherapy, Metacognitive Reflection and Insight Therapy, for individuals with early phase psychosis (MERIT-EP). Twenty adults with EPP and poor insight were randomized to either six months of MERIT-EP or treatment as usual (TAU). Therapists were trained and therapy was successfully delivered under routine, outpatient conditions. Insight, assessed before and after treatment, revealed significant improvement for the MERIT-EP, but not TAU, group. These results suggest MERIT-EP is feasible to deliver, accepted by patients, and leads to clinically significant improvements in insight. Copyright © 2017 Elsevier B.V. All rights reserved.
Prevalence, Patterns, and Genetic Association Analysis of Modic Vertebral Endplate Changes.
Kanna, Rishi Mugesh; Shanmuganathan, Rajasekaran; Rajagopalan, Veera Ranjani; Natesan, Senthil; Muthuraja, Raveendran; Cheung, Kenneth Man Chee; Chan, Danny; Kao, Patrick Yu Ping; Yee, Anita; Shetty, Ajoy Prasad
2017-08-01
A prospective genetic association study. The etiology of Modic changes (MCs) is unclear. Recently, the role of genetic factors in the etiology of MCs has been evaluated. However, studies with a larger patient subset are lacking, and candidate genes involved in other disc degeneration phenotypes have not been evaluated. We studied the prevalence of MCs and genetic association of 41 candidate genes in a large Indian cohort. MCs are vertebral endplate signal changes predominantly observed in the lumbar spine. A significant association between MCs and lumbar disc degeneration and nonspecific low back pain has been described, with the etiopathogenesis implicating various mechanical, infective, and biochemical factors. We studied 809 patients using 1.5-T magnetic resonance imaging to determine the prevalence, patterns, distribution, and type of lumbar MCs. Genetic association analysis of 71 single nucleotide polymorphisms (SNPs) of 41 candidate genes was performed based on the presence or absence of MCs. SNPs were genotyped using the Sequenome platform, and an association test was performed using PLINK software. The mean age of the study population (n=809) was 36.7±10.8 years. Based on the presence of MCs, the cohort was divided into 702 controls and 107 cases (prevalence, 13%). MCs were more commonly present in the lower (149/251, 59.4%) than in the upper (102/251, 40.6%) endplates. L4-5 endplates were the most commonly affected levels (30.7%). Type 2 MCs were the most commonly observed pattern (n=206, 82%). The rs2228570 SNP of VDR ( p =0.02) and rs17099008 SNP of MMP20 ( p =0.03) were significantly associated with MCs. Genetic polymorphisms of SNPs of VDR and MMP20 were significantly associated with MCs. Understanding the etiopathogenetic mechanisms of MCs is important for planning preventive and therapeutic strategies.
Ventral Dural Injury After Oblique Lumbar Interbody Fusion.
Chang, JaeChil; Kim, Jin-Sung; Jo, Hyunjin
2017-02-01
Oblique lumbar interbody fusion (OLIF) through the oblique corridor between the aorta and anterior border of psoas muscle is favored among spinal surgeons who employ minimally invasive techniques. We report a case of ventral dural tear after OLIF that was associated with the inaccurate trajectory direction of endplate preparation. This is the first report to our knowledge of ventral dural tear associated with OLIF. A 72-year-old woman presented with right leg pain and numbness. X-rays showed degenerative spondylolisthesis and loss of disc height at L4-L5 and L5-S1 levels. Magnetic resonance imaging revealed right-sided paracentral disc herniation at the L3-L4 level and foraminal disc herniation at L4-L5. The initial surgical plan was OLIF of L3-L4 and L4-L5 after percutaneous screw fixation without laminectomy. With the patient in the lateral position, discectomy and endplate preparation were done successfully at the L3-L4 level, and the same procedure was done at the L4-L5 level for OLIF. A sharp Cobbs elevator for endplate preparation triggered a ventral dural defect at the L4-L5 level. We changed the patient's position to attempt dural repair. The ventral dural defect could not be repaired because it was too large. After the herniated rootlets were repositioned, TachoComb was patched over the defect site. Postoperatively, the patient has no definite neurologic deficits. When a surgeon performs OLIF, ventral dural injury should be avoided during the procedure of endplate preparation and contralateral annular release. Copyright © 2016 Elsevier Inc. All rights reserved.
Log and data from a trench across the Hubbell Spring Fault Zone, Bernalillo County, New Mexico
Personius, S.F.; Eppes, M.C.; Mahan, S.A.; Love, D.W.; Mitchell, D.K.; Murphy, Anne
2000-01-01
This report contains field and laboratory data resulting from a trench study of the Hubbell Spring fault zone near Albuquerque, New Mexico. This trench was excavated in September, 1997, as part of earthquake hazards investigations of Quaternary faults in the Albuquerque metropolitan area. The trench was excavated across the youngest of several fault strands near the northern end of the Hubbell Spring fault zone. The site is located on Pueblo of Isleta tribal lands, approximately 1 km south of the southern boundary of Kirtland Air Force Base. Thus the paleoearthquake data derived from investigations at the Hubbell Spring site will be useful in assessing potential earthquake hazards in Isleta Pueblo, Kirtland Air Force Base/Sandia National Laboratories, and the Albuquerque metropolitan area. The purpose of this report is to present a detailed trench log, a scarp profile, soils data (table 1), magnetic susceptibility data (table 2), luminescence and uranium-series ages (tables 3 and 4), and detailed unit descriptions (table 5) obtained in this investigation. S.F. Personius had primary responsibility for siting, excavating, describing, and interpreting the trench; S.A. Mahan did the luminescence dating, and James B. Paces did the uranium-series dating. M.C. Eppes and D.W. Love assisted with trench logging and mapping; and M.C. Eppes, D.K. Mitchell, and A. Murphy did the soils analyses.
Rotation Capacity of Bolted Flush End-Plate Stiffened Beam-to-Column Connection
NASA Astrophysics Data System (ADS)
Ostrowski, Krzysztof; Kozłowski, Aleksander
2017-06-01
One of the flexibility parameters of semi-rigid joints is rotation capacity. Plastic rotation capacity is especially important in plastic design of framed structures. Current design codes, including Eurocode 3, do not posses procedures enabling designers to obtain value of rotation capacity. In the paper the calculation procedure of the rotation capacity for stiffened bolted flush end-plate beam-to-column connections has been proposed. Theory of experiment design was applied with the use of Hartley's PS/DS-P:Ha3 plan. The analysis was performed with the use of finite element method (ANSYS), based on the numerical experiment plan. The determination of maximal rotation angle was carried out with the use of regression analysis. The main variables analyzed in parametric study were: pitch of the bolt "w" (120-180 mm), the distance between the bolt axis and the beam upper edge cg1 (50-90 mm) and the thickness of the end-plate tp (10-20 mm). Power function was proposed to describe available rotation capacity of the joint. Influence of the particular components on the rotation capacity was also investigated. In the paper a general procedure for determination of rotation capacity was proposed.
Hizay, Arzu; Ozsoy, Umut; Demirel, Bahadir Murat; Ozsoy, Ozlem; Angelova, Srebrina K; Ankerne, Janina; Sarikcioglu, Sureyya Bilmen; Dunlop, Sarah A; Angelov, Doychin N; Sarikcioglu, Levent
2012-06-01
Despite increased understanding of peripheral nerve regeneration, functional recovery after surgical repair remains disappointing. A major contributing factor is the extensive collateral branching at the lesion site, which leads to inaccurate axonal navigation and aberrant reinnervation of targets. To determine whether the Y tube reconstruction improved axonal regrowth and whether this was associated with improved function. We used a Y-tube conduit with the aim of improving navigation of regenerating axons after facial nerve transection in rats. Retrograde labeling from the zygomatic and buccal branches showed a halving in the number of double-labeled facial motor neurons (15% vs 8%; P < .05) after Y tube reconstruction compared with facial-facial anastomosis coaptation. However, in both surgical groups, the proportion of polyinnervated motor endplates was similar (≈ 30%; P > .05), and video-based motion analysis of whisking revealed similarly poor function. Although Y-tube reconstruction decreases axonal branching at the lesion site and improves axonal navigation compared with facial-facial anastomosis coaptation, it fails to promote monoinnervation of motor endplates and confers no functional benefit.
Does bone cement in percutaneous vertebroplasty act as a stress riser?
Aquarius, René; van der Zijden, Astrid Maria; Homminga, Jasper; Verdonschot, Nico; Tanck, Esther
2013-11-15
An in vitro cadaveric study. To determine whether percutaneous vertebroplasty (PVP) with a clinically relevant amount of bone cement is capable of causing stress peaks in adjacent-level vertebrae. It is often suggested that PVP of a primary spinal fracture causes stress peaks in adjacent vertebrae, thereby leading to additional fractures. The in vitro studies that demonstrated this relationship, however, use bigger volumes of bone cement used clinically. Ten fresh-frozen vertebrae were loaded until failure, while registering force and displacement as well as the pressure under the lower endplate. After failure, the vertebrae were augmented with clinically relevant amounts of bone cement and then again loaded until failure. The force, displacement, and pressure under the lower endplate were again registered. Stress peaks were not related to the location of the injected bone cement. Both failure load and stiffness were significantly lower after augmentation. On the basis of our findings, we conclude that vertebral augmentation with clinically relevant amounts of bone cement does not lead to stress peaks under the endplate. It is therefore unlikely that PVP, in itself, causes detrimental stresses in the adjacent vertebrae, leading to new vertebral fractures. N/A.
Man, Yi; Zheng, Yue-huan; Cao, Peng; Chen, Bo; Zheng, Tao; Sun, Chang-hui; Lu, Jiong
2011-06-07
To test the nickel-titanium (Ni-Ti) shape memory alloys of vertebral body reduction fixator with assisted distraction bar for the treatment of traumatic and osteoporotic vertebral body fracture. A Ni-Ti shape memory alloys of vertebral body reduction fixator with assisted distraction bar was implanted into the compressed fracture specimens through vertebral pedicle with the radiographic monitoring to reduce the collapsed endplate as well as distract the compressed vertebral fracture. Radiographic film and computed tomographic reconstruction technique were employed to evaluate the effects of reduction and distraction. A biomechanic test machine was used to measure the fatigue and the stability of deformation of fixation segments. Relying on the effect of temperature shape memory, such an assembly could basically reduce the collapsed endplate as well as distract the compressed vertebral fracture. And when unsatisfied results of reduction and distraction occurred, its super flexibility could provide additional distraction strength. A Ni-Ti shape memory alloys of vertebral body reduction fixator with assisted distraction bar may provide effective endplate reduction, restore the vertebral height and the immediate biomechanic spinal stability. So the above assembly is indicated for the treatment of traumatic and osteoporotic vertebral body fracture.
Preconditioned mesenchymal stem cells treat myasthenia gravis in a humanized preclinical model
Sudres, Muriel; Maurer, Marie; Robinet, Marieke; Bismuth, Jacky; Truffault, Frédérique; Girard, Diane; Dragin, Nadine; Attia, Mohamed; Fadel, Elie; Santelmo, Nicola; Sicsic, Camille; Brenner, Talma
2017-01-01
Myasthenia gravis (MG) with anti–acetylcholine receptor (AChR) Abs is an autoimmune disease characterized by severe defects in immune regulation and thymic inflammation. Because mesenchymal stem cells (MSCs) display immunomodulatory features, we investigated whether and how in vitro–preconditioned human MSCs (cMSCs) could treat MG disease. We developed a new humanized preclinical model by subcutaneously grafting thymic MG fragments into immunodeficient NSG mice (NSG-MG model). Ninety percent of the animals displayed human anti-AChR Abs in the serum, and 50% of the animals displayed MG-like symptoms that correlated with the loss of AChR at the muscle endplates. Interestingly, each mouse experiment recapitulated the MG features of each patient. We next demonstrated that cMSCs markedly improved MG, reducing the level of anti-AChR Abs in the serum and restoring AChR expression at the muscle endplate. Resting MSCs had a smaller effect. Finally, we showed that the underlying mechanisms involved (a) the inhibition of cell proliferation, (b) the inhibition of B cell–related and costimulatory molecules, and (c) the activation of the complement regulator DAF/CD55. In conclusion, this study shows that a preconditioning step promotes the therapeutic effects of MSCs via combined mechanisms, making cMSCs a promising strategy for treating MG and potentially other autoimmune diseases. PMID:28405609
Holm, P. S.; Scanlon, K. J.; Dietel, M.
1994-01-01
A major problem in cytostatic treatment of many tumours is the development of multidrug resistance (MDR4). This is most often accompanied by the overexpression of a membrane transport protein, P-glycoprotein, and its encoding mRNA. In order to reverse the resistant phenotype in cell cultures, we constructed a specific hammerhead ribozyme possessing catalytic activity that cleaves the 3'-end of the GUC sequence in codon 880 of the mdr1 mRNA. We demonstrated that the constructed ribozyme is able to cleave a reduced substrate mdr1 mRNA at the GUC position under physiological conditions in a cell-free system. A DNA sequence encoding the ribozyme gene was then incorporated into a mammalian expression vector (pH beta APr-1 neo) and transfected into the human pancreatic carcinoma cell line EPP85-181RDB, which is resistant to daunorubicin and expresses the MDR phenotype. The expressed ribozyme decreased the level of mdr1 mRNA expression, inhibited the formation of P-glycoprotein and reduced the cell's resistance to daunorubicin dramatically; this means that the resistant cells were 1,600-fold more resistant than the parental cell line (EPP85-181P), whereas those cell clones that showed ribozyme expression were only 5.3-fold more resistant than the parental cell line. Images Figure 1 Figure 3 Figure 2 PMID:7914421
Evaluation of Physicians’ Awareness of Pediatric Diseases in Iran
Abolhassani, Hassan; Mirminachi, Babak; Daryabeigi, Maedeh; Agharahimi, Zahra; Aghamohammadi, Asghar; Rabbani, Ali; Rezaei, Nima
2014-01-01
Objective: Physicians’ awareness about pediatric health problems is very important in health system. This has not been investigated in Iran as yet. Therefore this study was conducted to characterize the knowledge of the Iranian physicians which has direct association with health status of children. Methods: One hundred and four physicians, mainly pediatric specialists (58.6%) working in the state hospitals (45.1%) were enrolled. They filled a valid and reliable questionnaire, containing 26 questions about basic and important pediatric issues before and after an educational pediatric program (EPP). Findings : Thirty nine (37.5%) physicians answered correctly more than 2/3 of all questions (passed the examination) before EPP, which increased to 42.3% after EEP. Subgroup analysis showed that the total scores of general practitioners (P=0.007) was significantly increased after the EPP. Moreover, physicians with shorter practicing time (P=0.006) and those with shorter time past graduation (P=0.01) had a significant improvement in their total scores after the program. The best scores of educational issues were documented in growth and development (16.0%; P=0.04), followed by dermatology (9.2%, P=0.04), urology (9.1%; P=0.04), and asthma and allergy (9.0%, P=0.04). Conclusion: This study revealed that there are gaps in the knowledge of professionals about the pediatric issues. PMID:25793051
Intraoperative intracavitary hyperthermic chemotherapy for malignant pleural mesothelioma
2017-01-01
Malignant pleural mesothelioma (MPM) is a dreadful disease with a poor prognosis. Multimodality therapy including surgical macroscopic complete resection is performed to treat operable MPM. Intraoperative intracavitary hyperthermic chemotherapy for MPM was reviewed. Appropriate papers published between 2006 and present were extracted by the PubMed advanced search by MPM (Title/Abstract), chemotherapy (Title/Abstract), and hyperthermia (All fields). Among the selected papers, those written in English, and treated more than ten MPM patients were reviewed. The intraoperative intracavitary hyperthermic chemotherapy has been performed following extrapleural pneumonectomy (EPP) or pleurectomy/decortication (P/D) for MPM. Cisplatin was mainly used for perfusion, and the morbidity and mortality was acceptable. In conclusion, the intraoperative intracavitary hyperthermic chemotherapy following EPP or P/D for MPM might enhance local control in the chest cavity. PMID:28706901
NASA Astrophysics Data System (ADS)
Funke, Bernd; Ball, William; Bender, Stefan; Gardini, Angela; Harvey, V. Lynn; Lambert, Alyn; López-Puertas, Manuel; Marsh, Daniel R.; Meraner, Katharina; Nieder, Holger; Päivärinta, Sanna-Mari; Pérot, Kristell; Randall, Cora E.; Reddmann, Thomas; Rozanov, Eugene; Schmidt, Hauke; Seppälä, Annika; Sinnhuber, Miriam; Sukhodolov, Timofei; Stiller, Gabriele P.; Tsvetkova, Natalia D.; Verronen, Pekka T.; Versick, Stefan; von Clarmann, Thomas; Walker, Kaley A.; Yushkov, Vladimir
2017-03-01
We compare simulations from three high-top (with upper lid above 120 km) and five medium-top (with upper lid around 80 km) atmospheric models with observations of odd nitrogen (NOx = NO + NO2), temperature, and carbon monoxide from seven satellite instruments (ACE-FTS on SciSat, GOMOS, MIPAS, and SCIAMACHY on Envisat, MLS on Aura, SABER on TIMED, and SMR on Odin) during the Northern Hemisphere (NH) polar winter 2008/2009. The models included in the comparison are the 3-D chemistry transport model 3dCTM, the ECHAM5/MESSy Atmospheric Chemistry (EMAC) model, FinROSE, the Hamburg Model of the Neutral and Ionized Atmosphere (HAMMONIA), the Karlsruhe Simulation Model of the Middle Atmosphere (KASIMA), the modelling tools for SOlar Climate Ozone Links studies (SOCOL and CAO-SOCOL), and the Whole Atmosphere Community Climate Model (WACCM4). The comparison focuses on the energetic particle precipitation (EPP) indirect effect, that is, the polar winter descent of NOx largely produced by EPP in the mesosphere and lower thermosphere. A particular emphasis is given to the impact of the sudden stratospheric warming (SSW) in January 2009 and the subsequent elevated stratopause (ES) event associated with enhanced descent of mesospheric air. The chemistry climate model simulations have been nudged toward reanalysis data in the troposphere and stratosphere while being unconstrained above. An odd nitrogen upper boundary condition obtained from MIPAS observations has further been applied to medium-top models. Most models provide a good representation of the mesospheric tracer descent in general, and the EPP indirect effect in particular, during the unperturbed (pre-SSW) period of the NH winter 2008/2009. The observed NOx descent into the lower mesosphere and stratosphere is generally reproduced within 20 %. Larger discrepancies of a few model simulations could be traced back either to the impact of the models' gravity wave drag scheme on the polar wintertime meridional circulation or to a combination of prescribed NOx mixing ratio at the uppermost model layer and low vertical resolution. In March-April, after the ES event, however, modelled mesospheric and stratospheric NOx distributions deviate significantly from the observations. The too-fast and early downward propagation of the NOx tongue, encountered in most simulations, coincides with a temperature high bias in the lower mesosphere (0.2-0.05 hPa), likely caused by an overestimation of descent velocities. In contrast, upper-mesospheric temperatures (at 0.05-0.001 hPa) are generally underestimated by the high-top models after the onset of the ES event, being indicative for too-slow descent and hence too-low NOx fluxes. As a consequence, the magnitude of the simulated NOx tongue is generally underestimated by these models. Descending NOx amounts simulated with medium-top models are on average closer to the observations but show a large spread of up to several hundred percent. This is primarily attributed to the different vertical model domains in which the NOx upper boundary condition is applied. In general, the intercomparison demonstrates the ability of state-of-the-art atmospheric models to reproduce the EPP indirect effect in dynamically and geomagnetically quiescent NH winter conditions. The encountered differences between observed and simulated NOx, CO, and temperature distributions during the perturbed phase of the 2009 NH winter, however, emphasize the need for model improvements in the dynamical representation of elevated stratopause events in order to allow for a better description of the EPP indirect effect under these particular conditions.
NASA Astrophysics Data System (ADS)
Akamatsu, G.; Ikari, Y.; Ohnishi, A.; Nishida, H.; Aita, K.; Sasaki, M.; Yamamoto, Y.; Sasaki, M.; Senda, M.
2016-08-01
Amyloid PET is useful for early and/or differential diagnosis of Alzheimer’s disease (AD). Quantification of amyloid deposition using PET has been employed to improve diagnosis and to monitor AD therapy, particularly in research. Although MRI is often used for segmentation of gray matter and for spatial normalization into standard Montreal Neurological Institute (MNI) space where region-of-interest (ROI) template is defined, 3D MRI is not always available in clinical practice. The purpose of this study was to examine the feasibility of PET-only amyloid quantification with an adaptive template and a pre-defined standard ROI template that has been empirically generated from typical cases. A total of 68 subjects who underwent brain 11C-PiB PET were examined. The 11C-PiB images were non-linearly spatially normalized to the standard MNI T1 atlas using the same transformation parameters of MRI-based normalization. The automatic-anatomical-labeling-ROI (AAL-ROI) template was applied to the PET images. All voxel values were normalized by the mean value of cerebellar cortex to generate the SUVR-scaled images. Eleven typical positive images and eight typical negative images were normalized and averaged, respectively, and were used as the positive and negative template. Positive and negative masks which consist of voxels with SUVR ⩾1.7 were extracted from both templates. Empirical PiB-prone ROI (EPP-ROI) was generated by subtracting the negative mask from the positive mask. The 11C-PiB image of each subject was non-rigidly normalized to the positive and negative template, respectively, and the one with higher cross-correlation was adopted. The EPP-ROI was then inversely transformed to individual PET images. We evaluated differences of SUVR between standard MRI-based method and PET-only method. We additionally evaluated whether the PET-only method would correctly categorize 11C-PiB scans as positive or negative. Significant correlation was observed between the SUVRs obtained with AAL-ROI and those with EPP-ROI when MRI-based normalization was used, the latter providing higher SUVR. When EPP-ROI was used, MRI-based method and PET-only method provided almost identical SUVR. All 11C-PiB scans were correctly categorized into positive and negative using a cutoff value of 1.7 as compared to visual interpretation. The 11C-PiB SUVR were 2.30 ± 0.24 and 1.25 ± 0.11 for the positive and negative images. PET-only amyloid quantification method with adaptive templates and EPP-ROI can provide accurate, robust and simple amyloid quantification without MRI.
The interaction between hexamethonium and tubocurarine on the rat neuromuscular junction.
Rang, H. P.; Rylett, R. J.
1984-01-01
The ability of hexamethonium (C6) to reverse the neuromuscular blocking action of tubocurarine (Tc) has been reinvestigated at the voltage clamped endplate of the omohyoid muscle of rat. The possibility that a weak anticholinesterase action of C6 could contribute to the paradoxical potentiation of the peak amplitude of the endplate response has been examined. C6 (50-200 microM) caused an increase in the amplitude of nerve-evoked endplate currents (e.p.cs) recorded in the presence of 0.6 microM Tc. The effect decreased with hyperpolarization of the muscle fibre. Irreversible inhibition of acetylcholinesterase resulted in a loss of the anti-curare effect of C6. C6 did not cause an increase in e.p.c. amplitude when acetylcholine (ACh) receptors were blocked irreversibly by alpha-bungaratoxin. When transmission was blocked by increased Mg2+ concentration, C6 (50-400 microM) reduced the amplitude of e.p.cs without appreciably affecting their time course. C6 caused a decrease in the amplitude of miniature endplate currents (m.e.p.cs) the effect being slightly increased when the fibre was hyperpolarized. An e-fold increase in the effectiveness of C6 occurred with approximately 58 mV hyperpolarization. High concentrations (greater than 400 microM) affected the time course of m.e.p.cs in a manner suggestive of open channel block, but this was not evident at 200 microM, the concentration that was most effective in reversing Tc block. When tested against responses to short ionophoretic pulses of agonists, C6 was less effective against ACh (EC50ca. 300 microM) than against carbachol (CCh) (EC50 100 microM). When cholinesterase was irreversibly inhibited, C6 blocked responses to both agonists equally (EC50ca. 100 microM). The effectiveness of C6 in blocking the action of CCh was reduced 10 fold in the presence of 0.6 microM Tc, implying that the two antagonists compete for the same binding site. C6 (50-200 microM) in the presence of Tc (0.6 microM) increased the response to ionophoretically applied ACh but not that to CCh. C6 was equipotent in blocking m.e.p.cs and responses to ionophoretically applied ACh whereas Tc was more potent against the exogenously applied agonist. C6 was a weak inhibitor of acetylcholinesterase activity in rat muscle homogenates (EC50 1.5 mM). The results are discussed in terms of the kinetic hypothesis advanced by Ginsborg & Stephenson (1974) to account for the Tc reversal phenomenon.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:6141831
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chance, William W.; Rice, David C.; Allen, Pamela K.
Purpose: To investigate safety, efficacy, and recurrence after hemithoracic intensity modulated radiation therapy after pleurectomy/decortication (PD-IMRT) and after extrapleural pneumonectomy (EPP-IMRT). Methods and Materials: In 2009-2013, 24 patients with mesothelioma underwent PD-IMRT to the involved hemithorax to a dose of 45 Gy, with an optional integrated boost; 22 also received chemotherapy. Toxicity was scored with the Common Terminology Criteria for Adverse Events v4.0. Pulmonary function was compared at baseline, after surgery, and after IMRT. Kaplan-Meier analysis was used to calculate overall survival (OS), progression-free survival (PFS), time to locoregional failure, and time to distant metastasis. Failures were in-field, marginal, or outmore » of field. Outcomes were compared with those of 24 patients, matched for age, nodal status, performance status, and chemotherapy, who had received EPP-IMRT. Results: Median follow-up time was 12.2 months. Grade 3 toxicity rates were 8% skin and 8% pulmonary. Pulmonary function declined from baseline to after surgery (by 21% for forced vital capacity, 16% for forced expiratory volume in 1 second, and 19% for lung diffusion of carbon monoxide [P for all = .01]) and declined still further after IMRT (by 31% for forced vital capacity [P=.02], 25% for forced expiratory volume in 1 second [P=.01], and 30% for lung diffusion of carbon monoxide [P=.01]). The OS and PFS rates were 76% and 67%, respectively, at 1 year and 56% and 34% at 2 years. Median OS (28.4 vs 14.2 months, P=.04) and median PFS (16.4 vs 8.2 months, P=.01) favored PD-IMRT versus EPP-IMRT. No differences were found in grade 4-5 toxicity (0 of 24 vs 3 of 24, P=.23), median time to locoregional failure (18.7 months vs not reached, P not calculable), or median time to distant metastasis (18.8 vs 11.8 months, P=.12). Conclusions: Hemithoracic intensity modulated radiation therapy after pleurectomy/decortication produced little high-grade toxicity but led to progressive declines in pulmonary function; OS and PFS were better in PD-IMRT compared with EPP-IMRT.« less
Chance, William W; Rice, David C; Allen, Pamela K; Tsao, Anne S; Fontanilla, Hiral P; Liao, Zhongxing; Chang, Joe Y; Tang, Chad; Pan, Hubert Y; Welsh, James W; Mehran, Reza J; Gomez, Daniel R
2015-01-01
To investigate safety, efficacy, and recurrence after hemithoracic intensity modulated radiation therapy after pleurectomy/decortication (PD-IMRT) and after extrapleural pneumonectomy (EPP-IMRT). In 2009-2013, 24 patients with mesothelioma underwent PD-IMRT to the involved hemithorax to a dose of 45 Gy, with an optional integrated boost; 22 also received chemotherapy. Toxicity was scored with the Common Terminology Criteria for Adverse Events v4.0. Pulmonary function was compared at baseline, after surgery, and after IMRT. Kaplan-Meier analysis was used to calculate overall survival (OS), progression-free survival (PFS), time to locoregional failure, and time to distant metastasis. Failures were in-field, marginal, or out of field. Outcomes were compared with those of 24 patients, matched for age, nodal status, performance status, and chemotherapy, who had received EPP-IMRT. Median follow-up time was 12.2 months. Grade 3 toxicity rates were 8% skin and 8% pulmonary. Pulmonary function declined from baseline to after surgery (by 21% for forced vital capacity, 16% for forced expiratory volume in 1 second, and 19% for lung diffusion of carbon monoxide [P for all = .01]) and declined still further after IMRT (by 31% for forced vital capacity [P=.02], 25% for forced expiratory volume in 1 second [P=.01], and 30% for lung diffusion of carbon monoxide [P=.01]). The OS and PFS rates were 76% and 67%, respectively, at 1 year and 56% and 34% at 2 years. Median OS (28.4 vs 14.2 months, P=.04) and median PFS (16.4 vs 8.2 months, P=.01) favored PD-IMRT versus EPP-IMRT. No differences were found in grade 4-5 toxicity (0 of 24 vs 3 of 24, P=.23), median time to locoregional failure (18.7 months vs not reached, P not calculable), or median time to distant metastasis (18.8 vs 11.8 months, P=.12). Hemithoracic intensity modulated radiation therapy after pleurectomy/decortication produced little high-grade toxicity but led to progressive declines in pulmonary function; OS and PFS were better in PD-IMRT compared with EPP-IMRT. Copyright © 2015 Elsevier Inc. All rights reserved.
Bassat, Quique; Mulenga, Modest; Tinto, Halidou; Piola, Patrice; Borrmann, Steffen; Menéndez, Clara; Nambozi, Michael; Valéa, Innocent; Nabasumba, Carolyn; Sasi, Philip; Bacchieri, Antonella; Corsi, Marco; Ubben, David; Talisuna, Ambrose; D'Alessandro, Umberto
2009-01-01
Background Artemisinin combination therapies (ACTs) are currently the preferred option for treating uncomplicated malaria. Dihydroartemisinin-piperaquine (DHA-PQP) is a promising fixed-dose ACT with limited information on its safety and efficacy in African children. Methodology/Principal Findings The non-inferiority of DHA-PQP versus artemether-lumefantrine (AL) in children 6–59 months old with uncomplicated P. falciparum malaria was tested in five African countries (Burkina Faso, Kenya, Mozambique, Uganda and Zambia). Patients were randomised (2∶1) to receive either DHA-PQP or AL. Non-inferiority was assessed using a margin of −5% for the lower limit of the one-sided 97.5% confidence interval on the treatment difference (DHA-PQP vs. AL) of the day 28 polymerase chain reaction (PCR) corrected cure rate. Efficacy analysis was performed in several populations, and two of them are presented here: intention-to-treat (ITT) and enlarged per-protocol (ePP). 1553 children were randomised, 1039 receiving DHA-PQP and 514 AL. The PCR-corrected day 28 cure rate was 90.4% (ITT) and 94.7% (ePP) in the DHA-PQP group, and 90.0% (ITT) and 95.3% (ePP) in the AL group. The lower limits of the one-sided 97.5% CI of the difference between the two treatments were −2.80% and −2.96%, in the ITT and ePP populations, respectively. In the ITT population, the Kaplan-Meier estimate of the proportion of new infections up to Day 42 was 13.55% (95% CI: 11.35%–15.76%) for DHA-PQP vs 24.00% (95% CI: 20.11%–27.88%) for AL (p<0.0001). Conclusions/Significance DHA-PQP is as efficacious as AL in treating uncomplicated malaria in African children from different endemicity settings, and shows a comparable safety profile. The occurrence of new infections within the 42-day follow up was significantly lower in the DHA-PQP group, indicating a longer post-treatment prophylactic effect. Trial Registration Controlled-trials.com ISRCTN16263443 PMID:19936217
Wan, Xiaomeng; Min, Yuanzeng; Bludau, Herdis; Keith, Andrew; Sheiko, Sergei S; Jordan, Rainer; Wang, Andrew Z; Sokolsky-Papkov, Marina; Kabanov, Alexander V
2018-03-27
Nanoparticle-based systems for concurrent delivery of multiple drugs can improve outcomes of cancer treatments, but face challenges because of differential solubility and fairly low threshold for incorporation of many drugs. Here we demonstrate that this approach can be used to greatly improve the treatment outcomes of etoposide (ETO) and platinum drug combination ("EP/PE") therapy that is the backbone for treatment of prevalent and deadly small cell lung cancer (SCLC). A polymeric micelle system based on amphiphilic block copolymer poly(2-oxazoline)s (POx) poly(2-methyl-2-oxazoline- block-2-butyl-2-oxazoline- block-2-methyl-2-oxazoline) (P(MeOx- b-BuOx- b-MeOx) is used along with an alkylated cisplatin prodrug to enable co-formulation of EP/PE in a single high-capacity vehicle. A broad range of drug mixing ratios and exceptionally high two-drug loading of over 50% wt. drug in dispersed phase is demonstrated. The highly loaded POx micelles have worm-like morphology, unprecedented for drug loaded polymeric micelles reported so far, which usually form spheres upon drug loading. The drugs co-loading in the micelles result in a slowed-down release, improved pharmacokinetics, and increased tumor distribution of both drugs. A superior antitumor activity of co-loaded EP/PE drug micelles compared to single drug micelles or their combination as well as free drug combination was demonstrated using several animal models of SCLC and non-small cell lung cancer.
Prevalence, Patterns, and Genetic Association Analysis of Modic Vertebral Endplate Changes
Kanna, Rishi Mugesh; Rajagopalan, Veera Ranjani; Natesan, Senthil; Muthuraja, Raveendran; Cheung, Kenneth Man Chee; Chan, Danny; Kao, Patrick Yu Ping; Yee, Anita; Shetty, Ajoy Prasad
2017-01-01
Study Design A prospective genetic association study. Purpose The etiology of Modic changes (MCs) is unclear. Recently, the role of genetic factors in the etiology of MCs has been evaluated. However, studies with a larger patient subset are lacking, and candidate genes involved in other disc degeneration phenotypes have not been evaluated. We studied the prevalence of MCs and genetic association of 41 candidate genes in a large Indian cohort. Overview of Literature MCs are vertebral endplate signal changes predominantly observed in the lumbar spine. A significant association between MCs and lumbar disc degeneration and nonspecific low back pain has been described, with the etiopathogenesis implicating various mechanical, infective, and biochemical factors. Methods We studied 809 patients using 1.5-T magnetic resonance imaging to determine the prevalence, patterns, distribution, and type of lumbar MCs. Genetic association analysis of 71 single nucleotide polymorphisms (SNPs) of 41 candidate genes was performed based on the presence or absence of MCs. SNPs were genotyped using the Sequenome platform, and an association test was performed using PLINK software. Results The mean age of the study population (n=809) was 36.7±10.8 years. Based on the presence of MCs, the cohort was divided into 702 controls and 107 cases (prevalence, 13%). MCs were more commonly present in the lower (149/251, 59.4%) than in the upper (102/251, 40.6%) endplates. L4–5 endplates were the most commonly affected levels (30.7%). Type 2 MCs were the most commonly observed pattern (n=206, 82%). The rs2228570 SNP of VDR (p=0.02) and rs17099008 SNP of MMP20 (p=0.03) were significantly associated with MCs. Conclusions Genetic polymorphisms of SNPs of VDR and MMP20 were significantly associated with MCs. Understanding the etiopathogenetic mechanisms of MCs is important for planning preventive and therapeutic strategies. PMID:28874978
Does location of rotation center in artificial disc affect cervical biomechanics?
Mo, Zhongjun; Zhao, Yanbin; Du, Chengfei; Sun, Yu; Zhang, Ming; Fan, Yubo
2015-04-15
A 3-dimensional finite element investigation. To compare the biomechanical performances of different rotation centers (RCs) in the prevalent artificial cervical discs. Various configurations are applied in artificial discs. Design parameters may influence the biomechanics of implanted spine. The RC is a primary variation in the popular artificial discs. Implantation of 5 prostheses was simulated at C5-C6 on the basis of a validated finite element cervical model (C3-C7). The prostheses included ball-in-socket design with a fixed RC located on the inferior endplate (BS-FI) and on the superior endplate (BS-FS), with a mobile RC at the inferior endplate (BS-MI), dual articulation with a mobile RC between the endplates (DA-M), and sliding articulation with various RCs (SA-V). The spinal motions in flexion and extension served as a displacement loading at the C3 vertebrae. Total disc replacements reduced extension moment. The ball-in-socket designs required less flexion moment, whereas the flexion stiffness of the spines with DA-M and SA-V was similar to that of the healthy model. The contributions of the implanted level to the global motions increased in the total disc replacements, except in the SA-V and DA-M models (in flexion). Ball-in-socket designs produced severe stress distributions in facet cartilage, whereas DA-M and SA-V produced more severe stress distribution on the bone-implant interface. Cervical stability was extremely affected in extension and partially affected in flexion by total disc replacement. With the prostheses with mobile RC, cervical curvature was readjusted under a low follower load. The SA-V and BS-FS designs exhibited better performances in the entire segmental stiffness and in the stability of the operative level than the BS-MI and BS-FI designs in flexion. The 5 designs demonstrated varying advantages relative to the stress distribution in the facet cartilages and on the bone-implant interface. 5.
Zone-dependent changes in human vertebral trabecular bone: clinical implications.
Thomsen, Jesper Skovhus; Ebbesen, E N; Mosekilde, Li
2002-05-01
We have previously shown that there are pronounced age-related changes in human vertebral cancellous bone density and microarchitecture. However, the magnitude of these changes seemed to be dependent on zone location in the vertebral body-the central third vs. the areas adjacent to the endplates. The aim of the present study was, therefore, to investigate whether such zone-specific differences could be identified by static histomorphometric measures. The material comprised 48 individuals (24 women aged 19-97 years, and 24 men aged 23-95 years). Three of the women had a known fracture of the L-2. From each L-2, thick frontal sections of half of the vertebra were embedded undecalcified in methylmethacrylate, cut into 10-microm-thick sections, and stained with aniline blue. The sections were scanned into a computer, and classic static histomorphometry was performed on the images. The histomorphometry was performed on both the whole section and on the separate zones (central and sub-endplate zone). The results showed that trabecular bone volume, trabecular number, and connectivity density decreased significantly faster with age, whereas marrow space star volume increased significantly faster with age in the zones adjacent to the endplates than in the central zone. The other histomorphometric measures showed no zone specificity in relation to aging. However, trabecular thickness and trabecular separation were both higher at all ages in the central zone than in the sub-endplate zone, although this was significant only for trabecular separation. The described differences might have significant clinical implications concerning quantitative computed tomography (QCT) scanning, X-ray analyses, and assessment of fracture liability in the human spine, but the underlying pathogenesis is still not known. This study shows that the human vertebral body can be described as two distinct zones with very specific age-related changes in density and microstructure. This zone-specificity is important for the correct interpretation of clinical data.
Stensby, J Derek; Kaliney, Ryan W; Alford, Bennett; Shen, Francis H; Patrie, James T; Fox, Michael G
2016-03-01
The purpose of this study is to determine whether recombinant human morphogenetic protein-2 (rhBMP-2) alters the findings on routine radiographs performed after transforaminal lumbar interbody fusion (TLIF). A retrospective review of 256 TLIF procedures in 200 patients was performed over a 4-year period. The rhBMP-2 group included 204 TLIFs in 160 patients, and the control group included 52 TLIFs in 40 patients. Two musculoskeletal radiologists reviewed the postoperative radiographs for endplate resorption, resorption resolution, new bone formation, bridging bone, and allograft migration. Statistical analysis was performed using logistic regression. The median age was 53 years in the rhBMP-2 group and 54 years in the control group (p = 0.182). The groups were similar with regard to sex (p = 0.517), single or multilevel TLIF (p = 0.921), specific TLIF levels (p = 0.53), and median radiographic follow-up (373 vs 366 days; p = 0.34). Findings that were more common in the rhBMP-2 group than in the control group included endplate resorption (38% [78/204] vs 12% [6/52]; odds ratio [OR], 4.67; 95% CI, 1.99-12.54; p < 0.001), resorption resolution (59% [46/78] vs 0% [0/6]; OR, 8.09; 95% CI, 1.41 to ∞; p = 0.022), new bone formation (84% [171/204] vs 67% [35/52]; OR, 2.51; 95% CI, 1.24-4.99; p = 0.011), bridging bone (55% [112/204] vs 31% [16/52]; OR, 2.73; 95% CI, 1.43-5.34; p = 0.002), and allograft migration (17% [35/204] vs 2% [1/52]; OR, 6.30; 95% CI, 0.91-151.41; p = 0.065). A statistically significant higher frequency of endplate resorption, new bone formation, and bone bridging is present in TLIF augmented by rhBMP-2 compared with TLIF performed without rhBMP-2. Endplate resorption resolves without treatment in most cases after rhBMP-2 use.
Qualitative Measurement of Environmentally Preferable Purchasing Among Federal Employees in 2000
The U.S. Environmental Protection Agency’s (EPA’s) Environmentally Preferable Purchasing (EPP) program is mandated by Executive Order 13101 to green the federal government. This was a study to determine federal attitudes.
Insights into public export promotion programs in an emerging economy: the case of Malaysian SMEs.
Ayob, Abu H; Freixanet, Joan
2014-10-01
This study evaluates the impact of public export promotion programs (EPPs) among small and medium-sized enterprises (SMEs) in Malaysia. Three indicators, level of awareness, frequency of use, and perception of usefulness, were examined according to a firm's export status. The global evaluation suggests that exporters are more frequent users of EPPs and perceive them to be more useful than non-exporters. Nonetheless, both groups demonstrate higher levels of awareness, are frequent users, and perceive the programs relating to export info/knowledge are more usefulness than programs relating to financial assistance. Further analysis also reveals that the frequency of use and the perception of usefulness for most programs are positively related to export experience, but not to export turnover. This study offers insights into the effectiveness of export programs for encouraging export initiation and expansion in an emerging economy. Copyright © 2014 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Al-Hashimi, M. H.; Wiese, U.-J.
2009-12-01
We consider wave packets of free particles with a general energy-momentum dispersion relation E(p). The spreading of the wave packet is determined by the velocity v=∂pE. The position-velocity uncertainty relation ΔxΔv⩾12|<∂p2E>| is saturated by minimal uncertainty wave packets Φ(p)=Aexp(-αE(p)+βp). In addition to the standard minimal Gaussian wave packets corresponding to the non-relativistic dispersion relation E(p)=p2/2m, analytic calculations are presented for the spreading of wave packets with minimal position-velocity uncertainty product for the lattice dispersion relation E(p)=-cos(pa)/ma2 as well as for the relativistic dispersion relation E(p)=p2+m2. The boost properties of moving relativistic wave packets as well as the propagation of wave packets in an expanding Universe are also discussed.
2017-11-30
jsc2017e136057 - On a snowy night at Red Square Moscow, Expedition 54-55 backup crewmembers Sergey Prokopyev of the Russian Federal Space Agency (Roscosmos, left), Jeanette Epps of NASA (center) and Alexander Gerst of the European Space Agency (right) pay homage at the Kremlin Wall where Russian space icons are interred in traditional pre-launch ceremonies Nov. 30. They are backups to Anton Shkaplerov of Roscosmos, Scott Tingle of NASA and Norishige Kanai of the Japan Aerospace Exploration Agency (JAXA), who will launch from the Baikonur Cosmodrome in Kazakhstan on the Soyuz MS-07 spacecraft Dec. 17 for a five-month mission on the International Space Station...Andrey Shelepin/Gagarin Cosmonaut Training Center.
2017-11-30
jsc2017e136055 - On a snowy night at Red Square in Moscow, Expedition 54-55 backup crewmember Jeanette Epps of NASA lays flowers at the Kremlin Wall where Russian space icons are interred in traditional pre-launch ceremonies Nov. 30. Looking on are backup crewmembers Sergey Prokopyev of the Russian Federal Space Agency (Roscosmos, left) and Alexander Gerst of the European Space Agency. They are backups to Anton Shkaplerov of Roscosmos, Scott Tingle of NASA and Norishige Kanai of the Japan Aerospace Exploration Agency (JAXA), who will launch from the Baikonur Cosmodrome in Kazakhstan on the Soyuz MS-07 spacecraft Dec. 17 for a five-month mission on the International Space Station...Andrey Shelepin/Gagarin Cosmonaut Training Center.
Ion acceleration in a helicon source due to the self-bias effect
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wiebold, Matt; Sung, Yung-Ta; Scharer, John E.
2012-05-15
Time-averaged plasma potential differences up to 165 V over several hundred Debye lengths are observed in low pressure (p{sub n} < 1 mTorr) expanding argon plasmas in the Madison Helicon eXperiment (MadHeX). The potential gradient leads to ion acceleration greater than that predicted by ambipolar expansion, exceeding E{sub i} Almost-Equal-To 7 kT{sub e} in some cases. RF power up to 500 W at 13.56 MHz is supplied to a half-turn, double-helix antenna in the presence of a nozzle magnetic field, adjustable up to 1 kG. A retarding potential analyzer (RPA) measures the ion energy distribution function (IEDF) and a sweptmore » emissive probe measures the plasma potential. Single and double probes measure the electron density and temperature. Two distinct mode hops, the capacitive-inductive (E-H) and inductive-helicon (H-W) transitions, are identified by jumps in density as RF power is increased. In the capacitive (E) mode, large fluctuations of the plasma potential (V{sub p-p} Greater-Than-Or-Equivalent-To 140V, V{sub p-p}/V{sub p} Almost-Equal-To 150%) exist at the RF frequency and its harmonics. The more mobile electrons can easily respond to RF-timescale gradients in the plasma potential whereas the inertially constrained ions cannot, leading to an initial flux imbalance and formation of a self-bias voltage between the source and expansion chambers. In the capacitive mode, the ion acceleration is not well described by an ambipolar relation, while in the inductive and helicon modes the ion acceleration more closely follows an ambipolar relation. The scaling of the potential gradient with the argon flow rate and RF power are investigated, with the largest potential gradients observed for the lowest flow rates in the capacitive mode. The magnitude of the self-bias voltage agrees with that predicted for RF self-bias at a wall. Rapid fluctuations in the plasma potential result in a time-dependent axial electron flux that acts to 'neutralize' the accelerated ion population, resulting in a zero net time-averaged current through the acceleration region when an insulating upstream boundary condition is enforced. Grounding the upstream endplate increases the self-bias voltage compared to a floating endplate.« less
NASA Astrophysics Data System (ADS)
Wiebold, Matthew D.
Time-averaged plasma potential differences up to ˜ 165 V over several hundred Debye lengths are observed in low pressure (pn < 1 mTorr) expanding argon plasmas in the Madison Helicon Experiment. The potential gradient leads to ion acceleration exceeding Ei ≈ 7 kTe in some cases. Up to 1 kW of 13.56 MHz RF power is supplied to a half-turn, double-helix antenna in the presence of a nozzle magnetic field up to 1 kG. An RPA measures the IEDF and an emissive probe measures the plasma potential. Single and double probes measure the electron density and temperature. Two distinct mode hops, the capacitive-inductive (E-H) and inductive-helicon (H-W) transitions, are identified by jumps in electron density as RF power is increased. In the capacitive mode, large fluctuations of the plasma potential (Vp--p ≳ 140 V, Vp--p/Vp ≈ 150%) exist at the RF frequency, leading to formation of a self-bias voltage. The mobile electrons can flow from the upstream region during an RF cycle whereas ions cannot, leading to an initial imbalance of flux, and the self-bias voltage builds as a result. The plasma potential in the expansion chamber is held near the floating potential for argon (Vp ≈ 5kTe/e). In the capacitive mode, the ion acceleration is not well described by an ambipolar relation. The accelerated population decay is consistent with that predicted by charge-exchange collisions. Grounding the upstream endplate increases the self-bias voltage compared to a floating endplate. In the inductive and helicon modes, the ion acceleration more closely follows an ambipolar relation, a result of decreased capacitive coupling due to the decreased RF skin depth. The scaling of the potential gradient with the argon flow rate, magnetic field and RF power are investigated, with the highest potential gradients observed for the lowest flow rates in the capacitive mode. The magnitude of the self-bias voltage agrees well with that predicted for RF sheaths. Use of the self-bias effect in a plasma thruster is explored, possibly for a low thrust, high specific impulse mode in a multi-mode helicon thruster. This work could also explain similar potential gradients in expanding helicon plasmas that are ascribed to double layer formation in the literature.
Valadão, Priscila Aparecida Costa; Naves, Lígia Araújo; Gomez, Renato Santiago; Guatimosim, Cristina
2013-11-01
Etomidate is an intravenous anesthetic used during anesthesia induction. This agent induces spontaneous movements, especially myoclonus after its administration suggesting a putative primary effect at the central nervous system or the periphery. Therefore, the aim of this study was to investigate the presynaptic and postsynaptic effects of etomidate at the mouse neuromuscular junction (NMJ). Diaphragm nerve muscle preparations were isolated and stained with the styryl dye FM1-43, a fluorescent tool that tracks synaptic vesicles exo-endocytosis that are key steps for neurotransmission. We observed that etomidate induced synaptic vesicle exocytosis in a dose-dependent fashion, an effect that was independent of voltage-gated Na(+) channels. By contrast, etomidate-evoked exocytosis was dependent on extracellular Ca(2+) because its effect was abolished in Ca(2+)-free medium and also inhibited by omega-Agatoxin IVA (30 and 200nM) suggesting the participation of P/Q-subtype Ca(2+) channels. Interestingly, even though etomidate induced synaptic vesicle exocytosis, we did not observe any significant difference in the frequency and amplitude of miniature end-plate potentials (MEPPs) in the presence of the anesthetic. We therefore investigated whether etomidate could act on nicotinic acetylcholine receptors labeled with α-bungarotoxin-Alexa 594 and we observed less fluorescence in preparations exposed to the anesthetic. In conclusion, our results suggest that etomidate exerts a presynaptic effect at the NMJ inducing synaptic vesicle exocytosis, likely through the activation of P-subtype voltage gated Ca(2+) channels without interfering with MEPPs frequency. The present data contribute to a better understanding about the effect of etomidate at the neuromuscular synapse and may help to explain some clinical effects of this agent. Copyright © 2013 Elsevier Ltd. All rights reserved.
Fields, Aaron J.; Berg-Johansen, Britta; Metz, Lionel N.; Miller, Stephanie; La, Brandan; Liebenberg, Ellen C.; Coughlin, Dezba G.; Graham, James L.; Stanhope, Kimber L.; Havel, Peter J.; Lotz, Jeffrey C.
2015-01-01
Type 2 diabetes (T2D) adversely affects many tissues, and the greater incidence of discogenic low back pain among diabetic patients suggests that the intervertebral disc is affected too. Using a rat model of polygenic obese T2D, we demonstrate that diabetes compromises several aspects of disc composition, matrix homeostasis and biomechanical behavior. Coccygeal motion segments were harvested from 6-month-old lean Sprague-Dawley rats, obese Sprague-Dawley rats, and diabetic obese UCD-T2DM rats (diabetic for 69 ± 7 days). Findings indicated that diabetes but not obesity reduced disc glycosaminoglycan and water contents, and these degenerative changes correlated with increased vertebral endplate thickness and decreased endplate porosity, and with higher levels of the advanced glycation end-product (AGE) pentosidine. Consistent with their diminished glycosaminoglycan and water contents and their higher AGE levels, discs from diabetic rats were stiffer and exhibited less creep when compressed. At the matrix level, elevated expression of hypoxia-inducible genes and catabolic markers in the discs from diabetic rats coincided with increased oxidative stress and greater interactions between AGEs and one of their receptors (RAGE). Taken together, these findings indicate that endplate sclerosis, increased oxidative stress and AGE/RAGE-mediated interactions could be important factors for explaining the greater incidence of disc pathology in T2D. PMID:25641259
DOE Office of Scientific and Technical Information (OSTI.GOV)
Krayenbuehl, Jerome; Hartmann, Matthias; Lomax, Anthony J.
Purpose: To perform comparative planning for intensity-modulated radiotherapy (IMRT) and proton therapy (PT) for malignant pleural mesothelioma after radical surgery. Methods and Materials: Eight patients treated with IMRT after extrapleural pleuropneumonectomy (EPP) were replanned for PT, comparing dose homogeneity, target volume coverage, and mean and maximal dose to organs at risk. Feasibility of PT was evaluated regarding the dose distribution with respect to air cavities after EPP. Results: Dose coverage and dose homogeneity of the planning target volume (PTV) were significantly better for PT than for IMRT regarding the volume covered by >95% (V95) for the high-dose PTV. The meanmore » dose to the contralateral kidney, ipsilateral kidney, contralateral lung, liver, and heart and spinal cord dose were significantly reduced with PT compared with IMRT. After EPP, air cavities were common (range, 0-850 cm{sup 3}), decreasing from 0 to 18.5 cm{sup 3}/day. In 2 patients, air cavity changes during RT decreased the generalized equivalent uniform dose (gEUD) in the case of using an a value of < - 10 to the PTV2 to <2 Gy in the presence of changing cavities for PT, and to 40 Gy for IMRT. Small changes were observed for gEUD of PTV1 because PTV1 was reached by the beams before air. Conclusion: Both PT and IMRT achieved good target coverage and dose homogeneity. Proton therapy accomplished additional dose sparing of most organs at risk compared with IMRT. Proton therapy dose distributions were more susceptible to changing air cavities, emphasizing the need for adaptive RT and replanning.« less
Sexual conflict arising from extrapair matings in birds.
Chaine, Alexis S; Montgomerie, Robert; Lyon, Bruce E
2015-01-20
The discovery that extrapair copulation (EPC) and extrapair paternity (EPP) are common in birds led to a paradigm shift in our understanding of the evolution of mating systems. The prevalence of extrapair matings in pair-bonded species sets the stage for sexual conflict, and a recent focus has been to consider how this conflict can shape variation in extrapair mating rates. Here, we invert the causal arrow and consider the consequences of extrapair matings for sexual conflict. Extrapair matings shift sexual conflict from a simple two-player (male vs. female) game to a game with three or more players, the nature of which we illustrate with simple diagrams that highlight the net costs and benefits of extrapair matings to each player. This approach helps identify the sorts of traits that might be under selection because of sexual conflict. Whether EPP is driven primarily by the extrapair male or the within-pair female profoundly influences which players are in conflict, but the overall pattern of conflict varies little among different mating systems. Different aspects of conflict are manifest at different stages of the breeding cycle and can be profitably considered as distinct episodes of selection caused by conflict. This perspective is illuminating both because conflict between specific players can change across episodes and because the traits that evolve to mediate conflict likely differ between episodes. Although EPP clearly leads to sexual conflict, we suggest that the link between sexual conflict and multiple paternity might be usefully understood by examining how deviations from lifetime sexual monogamy influence sexual conflict. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.
Sexual Conflict Arising from Extrapair Matings in Birds
Chaine, Alexis S.; Montgomerie, Robert; Lyon, Bruce E.
2015-01-01
The discovery that extrapair copulation (EPC) and extrapair paternity (EPP) are common in birds led to a paradigm shift in our understanding of the evolution of mating systems. The prevalence of extrapair matings in pair-bonded species sets the stage for sexual conflict, and a recent focus has been to consider how this conflict can shape variation in extrapair mating rates. Here, we invert the causal arrow and consider the consequences of extrapair matings for sexual conflict. Extrapair matings shift sexual conflict from a simple two-player (male vs. female) game to a game with three or more players, the nature of which we illustrate with simple diagrams that highlight the net costs and benefits of extrapair matings to each player. This approach helps identify the sorts of traits that might be under selection because of sexual conflict. Whether EPP is driven primarily by the extrapair male or the within-pair female profoundly influences which players are in conflict, but the overall pattern of conflict varies little among different mating systems. Different aspects of conflict are manifest at different stages of the breeding cycle and can be profitably considered as distinct episodes of selection caused by conflict. This perspective is illuminating both because conflict between specific players can change across episodes and because the traits that evolve to mediate conflict likely differ between episodes. Although EPP clearly leads to sexual conflict, we suggest that the link between sexual conflict and multiple paternity might be usefully understood by examining how deviations from lifetime sexual monogamy influence sexual conflict. PMID:25605708
Relich, R. F.; Doyle, L.; Espina, N.; Fuller, D.; Karchmer, T.; Lainesse, A.; Mortensen, J. E.; Pancholi, P.; Veros, W.; Harrington, S. M.
2016-01-01
Common causes of chronic diarrhea among travelers worldwide include protozoan parasites. The majority of parasitic infections are caused by Giardia duodenalis, Entamoeba histolytica, Cryptosporidium parvum, and Cryptosporidium hominis. Similarly, these species cause the majority of parasitic diarrhea acquired in the United States. Detection of parasites by gold standard microscopic methods is time-consuming and requires considerable expertise; enzyme immunoassays and direct fluorescent-antibody (DFA) stains have lowered hands-on time for testing, but improvements in sensitivity and technical time may be possible with a PCR assay. We performed a clinical evaluation of a multiplex PCR panel, the enteric parasite panel (EPP), for the detection of these common parasites using the BD Max instrument, which performs automated extraction and amplification. A total of 2,495 compliant specimens were enrolled, including 2,104 (84%) specimens collected prospectively and 391 (16%) specimens collected retrospectively. Approximately equal numbers were received in 10% formalin (1,273 specimens) and unpreserved (1,222 specimens). The results from the EPP were compared to those from alternate PCR and bidirectional sequencing (APCR), as well as DFA (G. duodenalis and C. parvum or C. hominis) or trichrome stain (E. histolytica). The sensitivity and specificity for prospective and retrospective specimens combined were 98.2% and 99.5% for G. duodenalis, 95.5% and 99.6 for C. parvum or C. hominis, and 100% and 100% for E. histolytica, respectively. The performance of the FDA-approved BD Max EPP compared well to the reference methods and may be an appropriate substitute for microscopic examination or immunoassays. PMID:27535690
Prognostic impact of peakVO2-changes in stable CHF on chronic beta-blocker treatment.
Frankenstein, L; Nelles, M; Hallerbach, M; Dukic, D; Fluegel, A; Schellberg, D; Katus, H A; Remppis, A; Zugck, C
2007-11-15
Peak oxygen uptake (pVO2) is used for risk stratification in chronic heart failure (CHF), but little is known about the prognostic impact of pVO2-changes in patients on chronic beta-blocker (BBL) therapy. We therefore prospectively evaluated individual pVO2-changes at a 6-month interval in patients all receiving BBL. 194 patients with stable CHF on stable medication were included (V1) and underwent clinical evaluation and exercise testing. Testing was repeated (V2) at 5.7+/-1.5 months after V1 and patients were followed >12 months after V2. Death or hospitalisation due to cardiac reasons was the predefined EP (EPP, end-point positive; n=62; EPN, end-point negative; n=113). Initial characteristics did not differ between EPP and EPN. Multivariate cox regression analysis revealed that change of pVO2 (EPP: -0.6+/-2.6 ml/kg min; EPN: +2.5+/-3.3 ml/kg min; p<0.001) was independent to pVO2, LVEF, NTproBNP and NYHA at V2 for prediction of the combined end-point during follow-up. An increase of pVO2 by 10% was identified as an adequate cut-off value for risk stratification and ROC-analysis showed the significant incremental prognostic value of the determination of pVO2 changes in combination with pVO2. Serial measurements of pVO2 yield additional information for risk stratification in clinically homogenous CHF patients receiving BBL. This is the first study demonstrating this fact within a narrow predefined interval with all patients on BBL.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 970.2301-1 Federal Acquisition Regulations System DEPARTMENT OF ENERGY AGENCY SUPPLEMENTARY REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Environment, Energy and Water Efficiency, Renewable Energy... http://www.hss.energy.gov/pp/epp. Contractors operating DOE facilities shall comply with the...
Self-Other Orientations and the Edwards Personal Preference Schedule
ERIC Educational Resources Information Center
Santee, Richard T.
1975-01-01
A modified version of the Edwards Personal Preference Schedule (EPPS) was administered to measure self and other orientations on 15 personality variables. The respondents were shown to have different preferences for themselves than for others. (Author/DEP)
A GLM Post-processor to Adjust Ensemble Forecast Traces
NASA Astrophysics Data System (ADS)
Thiemann, M.; Day, G. N.; Schaake, J. C.; Draijer, S.; Wang, L.
2011-12-01
The skill of hydrologic ensemble forecasts has improved in the last years through a better understanding of climate variability, better climate forecasts and new data assimilation techniques. Having been extensively utilized for probabilistic water supply forecasting, interest is developing to utilize these forecasts in operational decision making. Hydrologic ensemble forecast members typically have inherent biases in flow timing and volume caused by (1) structural errors in the models used, (2) systematic errors in the data used to calibrate those models, (3) uncertain initial hydrologic conditions, and (4) uncertainties in the forcing datasets. Furthermore, hydrologic models have often not been developed for operational decision points and ensemble forecasts are thus not always available where needed. A statistical post-processor can be used to address these issues. The post-processor should (1) correct for systematic biases in flow timing and volume, (2) preserve the skill of the available raw forecasts, (3) preserve spatial and temporal correlation as well as the uncertainty in the forecasted flow data, (4) produce adjusted forecast ensembles that represent the variability of the observed hydrograph to be predicted, and (5) preserve individual forecast traces as equally likely. The post-processor should also allow for the translation of available ensemble forecasts to hydrologically similar locations where forecasts are not available. This paper introduces an ensemble post-processor (EPP) developed in support of New York City water supply operations. The EPP employs a general linear model (GLM) to (1) adjust available ensemble forecast traces and (2) create new ensembles for (nearby) locations where only historic flow observations are available. The EPP is calibrated by developing daily and aggregated statistical relationships form historical flow observations and model simulations. These are then used in operation to obtain the conditional probability density function (PDF) of the observations to be predicted, thus jointly adjusting individual ensemble members. These steps are executed in a normalized transformed space ('z'-space) to account for the strong non-linearity in the flow observations involved. A data window centered on each calibration date is used to minimize impacts from sampling errors and data noise. Testing on datasets from California and New York suggests that the EPP can successfully minimize biases in ensemble forecasts, while preserving the raw forecast skill in a 'days to weeks' forecast horizon and reproducing the variability of climatology for 'weeks to years' forecast horizons.
Physiological basis of a steady endogenous current in rat lumbrical muscle
1984-01-01
In an attempt to determine the mechanism by which rat skeletal muscle endplates generate a steady outward current, we measured the effects of several drugs (furosemide, bumetanide, 9-anthracene carboxylic acid [9- AC]) and changes in external ion concentration (Na+, K+, Cl-, Ba++) on resting membrane potential (Vm) and on the steady outward current. Each of the following treatments caused a 10-15-mV hyperpolarization of the membrane: replacement of extracellular Cl- with isethionate, addition of furosemide or bumetanide, and addition of 9-AC. These results suggest that Cl- is actively accumulated by the muscle fibers and that the equilibrium potential of Cl- is more positive than the membrane potential. Removal of external Na+ also caused a large hyperpolarization and is consistent with evidence in other tissues that active Cl- accumulation requires external Na+. The same treatments greatly reduced or abolished the steady outward current, with a time course that paralleled the changes in Vm. These results cannot be explained by a model in which the steady outward current is assumed to arise as a result of a nonuniform distribution of Na+ conductance, but they are consistent with models in which the steady current is produced by a nonuniform distribution of GCl or GK. Other treatments (Na+-free and K+-free solutions, and 50 microM BaCl2) caused a temporary reversal of the steady current. Parallel measurements of Vm suggested that in none of these cases did the electrochemical driving force for K+ change sign, which makes it unlikely that the steady current arises as a result of a nonuniform distribution of GK. All of the results, however, are consistent with a model in which the steady outward current arises as a result of a nonuniform distribution of Cl- conductance, with GCl lower near the endplate than in extrajunctional regions. PMID:6325581
Garcia, N; Santafe, M M; Tomas, M; Lanuza, M A; Besalduch, N; Tomas, J
2010-01-01
We use immunocytochemistry to show that neurotrophin-4 (NT-4) and its receptor proteins (p75(NTR) and tropomyosin-related tyrosine kinase B) are present in neonatal neuromuscular junctions (NMJ) colocalized with several synaptic markers. NT-4 incubation (1h, in the range 2-12 nM) does not change the size of the endplate potential between P6 and P45. However, extended exposure (3h) to a relatively low dose of NT-4 (2 nM) potentiates ACh release (approx. 70%) in adult but not in neonatal muscles. The present results suggest that the developmental mechanism of axonal competition and neonatal elimination of redundant synapses cannot be modulated by added NT-4. However, this neurotrophin was able to modulate synaptic transmission locally in the adult NMJ.
Blood lead and the symptoms of lead absorption
Williams, M K; Walford, Joan; King, E
1983-01-01
ABSTRACT Eighty-one percent of all hourly paid men who had been employed for more than six months in a factory making lead acid batteries and plastics completed a modified Cornell medical index health questionnaire. Blood lead and erythrocyte protoporphyrin (EPP) were also measured. The questions were grouped into symptom categories as follows: all physical, all psychological, “potentially lead induced,” pulmonary, cardiovascular, gastrointestinal, skin, nervous system, genitourinary, and fatigue. For each symptom category the pooled percentages of men whose symptom scores were above the common median of the three blood lead groups 10-, 40-, and 60 and over μg/100 ml (0·48-, 1·93-, and 2·90 and over μmol/l) within age/smoking subgroups were calculated. In every symptom category the percentages in the two lower blood lead groups differed little, but the percentages were consistently higher in men with blood concentration of 60 μg/100 ml (2·90 μmol/l) and over. Differences between a combined 10-59 μg/100 ml (0·48-2·85 μmol/l) blood lead group and the 60 and over μg/100 ml (≥2·90 μmol/l) group were statistically significant at the 0·01 level for “potentially lead induced” symptoms and at the 0·05 level for skin and psychological symptoms. Broadly similar results were obtained with four log10 EPP groups 0·6-, 1·5-, 1·7-, and ≥2·0, but differences did not reach statistical significance. There was no obvious explanation as to why symptoms that are not found in classic lead poisoning should be increased almost as much as those that are. It was thought that these results could be biased due to the men's knowledge of the symptoms associated with lead exposure, but the possibility that they may be partly due to lead absorption cannot be excluded. PMID:6871117
NASA Astrophysics Data System (ADS)
Satyanarayana, G.; Narayana, K. L.; Boggarapu, Nageswara Rao
2018-03-01
In the nuclear industry, a critical welding process is joining of an end plate to a fuel rod to form a fuel bundle. Literature on zirconium welding in such a critical operation is limited. A CFD model is developed and performed for the three-dimensional non-linear thermo-fluid analysis incorporating buoyancy and Marnangoni stress and specifying temperature dependent properties to predict weld geometry and temperature field in and around the melt pool of laser spot during welding of a zirconium alloy E110 endplate with a fuel rod. Using this method, it is possible to estimate the weld pool dimensions for the specified laser power and laser-on-time. The temperature profiles will estimate the HAZ and microstructure. The adequacy of generic nature of the model is validated with existing experimental data.
Mwale, F; Roughley, P; Antoniou, J
2004-12-15
Tissue engineering of intervertebral discs (IVD) using mesenchymal stem cells (MSCs) induced to differentiate into a disc-cell phenotype has been considered as an alternative treatment for disc degeneration. However, since there is no unique marker characteristic of discs and since hyaline cartilage and immature nucleus pulposus (NP) possess similar macromolecules in their extracellular matrix, it is currently difficult to recognize MSC conversion to a disc cell. This study was performed to compare the proteoglycan to collagen ratio (measured as GAG to hydroxyproline ratio) in the NP of normal disc to that of the hyaline cartilage of the endplate within the same group of individuals and test the hypothesis that this ratio can be used for in vivo studies to distinguish between a normal NP and hyaline cartilage phenotype. Whole human lumbar spine specimens from fresh cadavers, ranging in age from 12 weeks to 79 years, were used to harvest the IVDs and adjacent endplates. The GAG to hydroxyproline ratio within the NP of young adults is approximately 27:1, whereas the ratio within the hyaline cartilage endplate of the same aged individuals is about 2:1. The production of an extracellular matrix with a high proteoglycan to collagen ratio can be used in vivo to distinguish NP cells from chondrocytes, and could help in identifying a NP-like phenotype in vivo as opposed to a chondrocyte when MSCs are induced to differentiate for tissue engineering of a disc.
[Establishment and validation of normal human L1-L5 lumbar three-dimensional finite element model].
Zhu, Zhenqi; Liu, Chenjun; Wang, Jiefu; Wang, Kaifeng; Huang, Zhixin; Wang, Weida; Liu, Haiying
2014-10-14
To create and validate a L1-L5 lumbar three-dimensional finite element model. The L1-L5 lumbar spines of a male healthy volunteer were scanned with computed tomography (CT). And a L1-L5 lumbar three-dimensional finite element model was created with the aid of software packages of Mimics, Geomagic and Ansys. Then border conditions were set, unit type was determined, finite element mesh was divided and a model was established for loading and calculating. Average model stiffness under the conditions of flexion, extension, lateral bending and axial rotation was calculated and compared with the outcomes of former articles for validation. A normal human L1-L5 lumbar three-dimensional finite element model was established to include 459 340 elements and 661 938 nodes. After constraining the inferior endplate of L5 vertebral body, 500 kg × m × s⁻² compressive loading was imposed averagely on the superior endplate of L1 vertebral body. Then 10 kg × m² × s⁻² moment simulating flexion, extension, lateral bending and axial rotation were imposed on the superior endplate of L1 vertebral body. Eventually the average stiffness of all directions was calculated and it was similar to the outcomes of former articles. The L1-L5 lumbar three-dimensional finite element model is validated so that it may used with biomechanical simulation and analysis of normal or surgical models.
Godano, Elisabetta; Morana, Giovanni; Di Iorgi, Natascia; Pistorio, Angela; Allegri, Anna Elsa Maria; Napoli, Flavia; Gastaldi, Roberto; Calcagno, Annalisa; Patti, Giuseppa; Gallizia, Annalisa; Notarnicola, Sara; Giaccardi, Marta; Noli, Serena; Severino, Mariasavina; Tortora, Domenico; Rossi, Andrea; Maghnie, Mohamad
2018-06-01
To investigate the role of T2-DRIVE MRI sequence in the accurate measurement of pituitary stalk (PS) size and the identification of PS abnormalities in patients with hypothalamic-pituitary disorders without the use of gadolinium. This was a retrospective study conducted on 242 patients who underwent MRI due to pituitary dysfunction between 2006 and 2015. Among 135 eligible patients, 102 showed eutopic posterior pituitary (PP) gland and 33 showed 'ectopic' PP (EPP). Two readers independently measured the size of PS in patients with eutopic PP at the proximal, midpoint and distal levels on pre- and post-contrast T1-weighted as well as T2-DRIVE images; PS visibility was assessed on pre-contrast T1 and T2-DRIVE sequences in those with EPP. The length, height, width and volume of the anterior pituitary (AP), PP height and length and PP area were analyzed. Significant agreement between the two readers was obtained for T2-DRIVE PS measurements in patients with 'eutopic' PP; a significant difference was demonstrated between the intraclass correlation coefficient calculated on the T2-DRIVE and the T1-pre- and post-contrast sequences. The percentage of PS identified by T2-DRIVE in EPP patients was 72.7% compared to 30.3% of T1 pre-contrast sequences. A significant association was found between the visibility of PS on T2-DRIVE and the height of AP. T2-DRIVE sequence is extremely precise and reliable for the evaluation of PS size and the recognition of PS abnormalities; the use of gadolinium-based contrast media does not add significant information and may thus be avoided. © 2018 European Society of Endocrinology.
NASA Technical Reports Server (NTRS)
Freesland, Doug; Carter, Delano; Chapel, Jim; Clapp, Brian; Howat, John; Krimchansky, Alexander
2015-01-01
The Geostationary Operational Environmental Satellite-R Series (GOES-R) is the first of the next generation geostationary weather satellites, scheduled for delivery in late 2015. GOES-R represents a quantum increase in Earth and solar weather observation capabilities, with 4 times the resolution, 5 times the observation rate, and 3 times the number of spectral bands for Earth observations. With the improved resolution, comes the instrument suite's increased sensitive to disturbances over a broad spectrum 0-512 Hz. Sources of disturbance include reaction wheels, thruster firings for station keeping and momentum management, gimbal motion, and internal instrument disturbances. To minimize the impact of these disturbances, the baseline design includes an Earth Pointed Platform (EPP), a stiff optical bench to which the two nadir pointed instruments are collocated together with the Guidance Navigation & Control (GN&C) star trackers and Inertial Measurement Units (IMUs). The EPP is passively isolated from the spacecraft bus with Honeywell D-Strut isolators providing attenuation for frequencies above approximately 5 Hz in all six degrees-of-freedom. A change in Reaction Wheel Assembly (RWA) vendors occurred very late in the program. To reduce the risk of RWA disturbances impacting performance, a secondary passive isolation system manufactured by Moog CSA Engineering was incorporated under each of the six 160 Nms RWAs, tuned to provide attenuation at frequencies above approximately 50 Hz. Integrated wheel and isolator testing was performed on a Kistler table at NASA Goddard Space Flight Center. High fidelity simulations were conducted to evaluate jitter performance for four topologies: 1) hard mounted no isolation, 2) EPP isolation only, 2) RWA isolation only, and 4) dual isolation. Simulation results demonstrate excellent performance relative to the pointing stability requirements, with dual isolated Line of Sight (LOS) jitter less than 1 micron rad.
Huang, Tzu-ting; Yeh, Chieh-Ying; Tsai, Yc-Chen
2011-04-01
to examine the effect of individual counselling on diet and physical activity from pregnancy to six months post partum, or from birth to six months post partum, on weight retention among Taiwanese women. a randomised controlled trial assigned participants to two experimental groups [from pregnancy to six months post partum (EP) and from birth to six months post partum (EPP)] and one comparison group. a 3900-bed medical centre in northern Taiwan with around 3000 births annually. a sample of 189 women who had regular check-ups during pregnancy and gave birth at the medical centre. the comparison group received the routine outpatient department obstetric educational programme. The EP group attended regularly scheduled clinic visits with individualised dietary and physical activity education plans from 16 gestational weeks to six months post partum, and received on brochure. The EPP group received the same educational intervention as the EP group from 24-48 hours after birth to six months post partum. body weight, body mass index, health-promoting behaviour and psycho-social variables (self-efficacy, body image, depression and social support). average gestational weight gain was 14.02, 15.27 and 16.22 kg in the three EP, EPP and comparison groups respectively, and average weight retention at six months post partum was 2.34, 4.06 and 5.08 kg in the three groups, respectively. a diet and physical activity intervention from pregnancy is effective for reducing post-pregnancy weight retention. the findings of the present study should be taken into consideration when incorporating significant others and weight-loss maintenance strategies with interventions for a healthier family lifestyle. Copyright © 2009 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Verronen, P. T.; Andersson, M. E.; Marsh, D. R.; Kovacs, T.; Plane, J. M. C.; Päivärinta, S. M.
2016-12-01
Energetic particle precipitation (EPP) and ion chemistry affect the neutral composition of the polar middle atmosphere. For example, production of odd nitrogen and odd hydrogen during EPP events can decrease ozone by tens of percent. However, the standard ion chemistry parameterizations used in atmospheric models neglect the effects on some important species, such as nitric acid. We present WACCM-D, a variant of the Whole Atmosphere Community Climate Model, which includes a set of lower ionosphere (D-region) chemistry: 307 reactions of 20 positive ions and 21 negative ions. Compared to the Sodankylä Ion and Neutral Chemistry (SIC), a state-of-the-art 1-D model of the D-region chemistry, WACCM-D represents the lower ionosphere well. Comparison of ion concentrations between the models shows that the WACCM-D bias is typically within ±10% or less below 70 km. At 70-90 km, when strong altitude gradients in ionization rates and/or ion concentrations exist, the bias can be larger for some ions but is still within tens of percent. We also compare WACCM-D results for the January 2005 solar proton event (SPE) to those from the standard WACCM and observations from the Aura/MLS and SCISAT/ACE-FTS instruments. The results indicate that WACCM-D improves the modeling of {HNO3}, {HCl}, {ClO}, {OH}, and {NOx} during the SPE. For example, Northern Hemispheric {HNO3} from WACCM-D shows an increase by two orders of magnitude at 40-70 km compared to WACCM, reaching 2.6 ppbv, in agreement with the observations. Based on our results, WACCM-D provides a state-of-the-art global representation of D-region ion chemistry and improves modeling of EPP atmospheric effects considerably.
An Investigation on Low Velocity Impact Response of Multilayer Sandwich Composite Structures
Jedari Salami, S.; Sadighi, M.; Shakeri, M.; Moeinfar, M.
2013-01-01
The effects of adding an extra layer within a sandwich panel and two different core types in top and bottom cores on low velocity impact loadings are studied experimentally in this paper. The panel includes polymer composite laminated sheets for faces and the internal laminated sheet called extra layer sheet, and two types of crushable foams are selected as the core material. Low velocity impact tests were carried out by drop hammer testing machine to the clamped multilayer sandwich panels with expanded polypropylene (EPP) and polyurethane rigid (PUR) in the top and bottom cores. Local displacement of the top core, contact force and deflection of the sandwich panel were obtained for different locations of the internal sheet; meanwhile the EPP and PUR were used in the top and bottom cores alternatively. It was found that the core material type has made significant role in improving the sandwich panel's behavior compared with the effect of extra layer location. PMID:24453804
2007-06-01
objectives, and because of their 26 Kotler Philip and Keller Kevin Lane, Marketing Management 12e...pp. 143-156. Kotler , Philip and Keller, Kevin Lane. Marketing Management 12e, Prentice Hall, 2005. NPS Academic Catalog 2007. NPS Registrar Office
2014-07-22
JSC2014-E-068003 (July 2014) --- NASA astronaut Jeanette Epps and European Space Agency astronaut Thomas Pesquet, who represent half the NEEMO 18 crew, waste little time in performing experiments and other assignments inside a 400 square-foot habitat housing them for nine days underwater off Key Largo. Photo credit: NASA
Fatal pneumonitis associated with intensity-modulated radiation therapy for mesothelioma
DOE Office of Scientific and Technical Information (OSTI.GOV)
Allen, Aaron M.; Czerminska, Maria; Jaenne, Pasi A.
2006-07-01
Purpose: To describe the initial experience at Dana-Farber Cancer Institute/Brigham and Women's Hospital with intensity-modulated radiation therapy (IMRT) as adjuvant therapy after extrapleural pneumonectomy (EPP) and adjuvant chemotherapy. Methods and Materials: The medical records of patients treated with IMRT after EPP and adjuvant chemotherapy were retrospectively reviewed. IMRT was given to a dose of 54 Gy to the clinical target volume in 1.8 Gy daily fractions. Treatment was delivered with a dynamic multileaf collimator using a sliding window technique. Eleven of 13 patients received heated intraoperative cisplatin chemotherapy (225 mg/m{sup 2}). Two patients received neoadjuvant intravenous cisplatin/pemetrexed, and 10 patientsmore » received adjuvant cisplatin/pemetrexed chemotherapy after EPP but before radiation therapy. All patients received at least 2 cycles of intravenous chemotherapy. The contralateral lung was limited to a V20 (volume of lung receiving 20 Gy or more) of 20% and a mean lung dose (MLD) of 15 Gy. All patients underwent fluorodeoxyglucose positron emission tomography (FDG-PET) for staging, and any FDG-avid areas in the hemithorax were given a simultaneous boost of radiotherapy to 60 Gy. Statistical comparisons were done using two-sided t test. Results: Thirteen patients were treated with IMRT from December 2004 to September 2005. Six patients developed fatal pneumonitis after treatment. The median time from completion of IMRT to the onset of radiation pneumonitis was 30 days (range 5-57 days). Thirty percent of patients (4 of 13) developed acute Grade 3 nausea and vomiting. One patient developed acute Grade 3 thrombocytopenia. The median V20, MLD, and V5 (volume of lung receiving 5 Gy or more) for the patients who developed pneumonitis was 17.6% (range, 15.3-22.3%), 15.2 Gy (range, 13.3-17 Gy), and 98.6% (range, 81-100%), respectively, as compared with 10.9% (range, 5.5-24.7%) (p = 0.08), 12.9 Gy (range, 8.7-16.9 Gy) (p = 0.07), and 90% (range, 66-98.3%) (p = 0.20), respectively, for the patients who did not develop pneumonitis. Conclusions: Intensity-modulated RT treatment for mesothelioma after EPP and adjuvant chemotherapy resulted in a high rate of fatal pneumonitis when standard dose parameters were used. We therefore recommend caution in the utilization of this technique. Our data suggest that with IMRT, metrics such as V5 and MLD should be considered in addition to V20 to determine tolerance levels in future patients.« less
1985-04-04
S85-29711 (April 1985) --- Ronald C. Epps, right of the training division in the mission operations directorate, briefs the Saudi Arabian payload specialist, Sultan Salman Abdelazize Al-Saud, and his backup, Abdulmohsen Hamad Al-Bassam, in the flight control room (FCR) of the mission control center (MCC). Erlinda Stevenson is also pictured.
Teacher Perceptions of Administrator Leadership Styles Regarding Job Satisfaction
ERIC Educational Resources Information Center
Johnson, Zachary Tyler
2017-01-01
One of the greatest challenges within education is a growing shortage of teachers (Epps & Foor, 2015). Various factors can be attributed to this phenomenon; however, two major factors that influence teachers to leave the profession are accountability and administrator leadership styles (Weinbaum, Weis, & Beaver, 2012). These two factors…
Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-08
... support of the scholarship application by academic professors/advisors. NOAA OEd student scholar alumni... are required to update the student tracker database with the required student information. In addition... System database form, 17 hours; undergraduate application form, 8 hours; reference forms, 1 hour; alumni...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-09
... form in support of the scholarship application by academic professors/advisors. NOAA OEd student... grantees are required to update the student tracker database with the required student information. In... Tracking System database form, 17 hours; undergraduate application form, 8 hours; reference forms, 1 hour...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-22
... completion of a NOAA student scholar reference form in support of the scholarship application by academic... internal tracking purposes. NOAA OEd grantees are required to update the student tracker database with the... tracker database form, 16 hours; graduate application form, 8 hours; undergraduate application form, 8...
The Role of International School Counselors in U.S. College Recruitment Strategy
ERIC Educational Resources Information Center
Foley, Amy Greenwald
2013-01-01
The University of Delaware has embraced a global admissions initiative with minimal experience in international endeavors and a limited budget for international recruitment. This EPP serves as exploratory research for improving our understanding of the international student market in Latin America and working more effectively with international…
PERSONALITY CHARACTERISTICS OF INNOVATIVE PHYSICS TEACHERS.
ERIC Educational Resources Information Center
WALBERG, HERBERT J.; WELCH, WAYNE W.
TO DETERMINE HOW THE INNOVATIVE PHYSICS TEACHER'S PERSONALITY DIFFERS FROM HIS NON-INNOVATIVE COLLEAGUE'S AND HOW HIS PERSONALITY IS RELATED TO HIS KNOWLEDGE OF PHYSICS AND HIS ATTITUDES TOWARD TEACHING, 36 MALE PHYSICS TEACHERS WERE GIVEN THE ALLPORT-VERNON-LINDZEY STUDY OF VALUES (AVL), THE EDWARDS PERSONAL PREFERENCE SCHEDULE (EPPS), THE…
Getting Home on Time: Predicting Timely Permanence for Young Children.
ERIC Educational Resources Information Center
Potter, Cathryn C.; Klein-Rothschild, Susan
2002-01-01
Studied the multivariate predictors of timely permanence for children served by Colorado's Expedited Permanency Planning (EPP) Project. Used qualitative interviews with child welfare and court personnel to identify critical barriers to and supports for effective permanency planning focusing on the areas of: (1) concurrent planning practice and…
Van der Kloot, W
1988-01-01
1. Following motor nerve stimulation there is a period of greatly enhanced quantal release, called the early release period or ERP (Barrett & Stevens, 1972b). Until now, measurements of the probability of quantal releases at different points in the ERP have come from experiments in which quantal output was greatly reduced, so that the time of release of individual quanta could be detected or so that the latency to the release of the first quantum could be measured. 2. A method has been developed to estimate the timing of quantal release during the ERP that can be used at much higher levels of quantal output. The assumption is made that each quantal release generates an end-plate current (EPC) that rises instantaneously and then decays exponentially. The peak amplitude of the quantal currents and the time constant for their decay are measured from miniature end-plate currents (MEPCs). Then a number of EPCs are averaged, and the times of release of the individual quanta during the ERP estimated by a simple mathematical method for deconvolution derived by Cohen, Van der Kloot & Attwell (1981). 3. The deconvolution method was tested using data from preparations in high-Mg2+ low-Ca2+ solution. One test was to reconstitute the averaged EPCs from the estimated times of quantal release and the quantal currents, by using Fourier convolution. The reconstructions fit well to the originals. 4. Reconstructions were also made from averaged MEPCs which do not rise instantaneously and the estimated times of quantal release.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2466987
Walter, BA; Illien-Junger, S; Nasser, P; Hecht, AC; Iatridis, JC
2014-01-01
Intervertebral disc (IVD) degeneration is a common cause of back pain, and attempts to develop therapies are frustrated by lack of model systems that mimic the human condition. Human IVD organ culture models can address this gap, yet current models are limited since vertebral endplates are removed to maintain cell viability, physiological loading is not applied, and mechanical behaviors are not measured. This study aimed to (i) establish a method for isolating human IVDs from autopsy with intact vertebral endplates, and (ii) develop and validate an organ culture loading system for human or bovine IVDs. Human IVDs with intact endplates were isolated from cadavers within 48 hours of death and cultured for up to 21 days. IVDs remained viable with ~80% cell viability in nucleus and annulus regions. A dynamic loading system was designed and built with the capacity to culture 9 bovine or 6 human IVDs simultaneously while applying simulated physiologic loads (maximum force: 4kN) and measuring IVD mechanical behaviors. The loading system accurately applied dynamic loading regimes (RMS error <2.5N and total harmonic distortion <2.45%), and precisely evaluated mechanical behavior of rubber and bovine IVDs. Bovine IVDs maintained their mechanical behavior and retained >85% viable cells throughout the 3 week culture period. This organ culture loading system can closely mimic physiological conditions and be used to investigate response of living human and bovine IVDs to mechanical and chemical challenges and to screen therapeutic repair techniques. PMID:24725441
Jesse, Mary Kristen; Petersen, Brian; Glueck, Deborah; Kriedler, Sarah
2015-01-01
The most widely researched risk/complication following vertebroplasty (VP) or kyphoplasty (KP) is that of adjacent level fracture (ALF). Current literature results regarding the effect of intradiscal extravasation of cement on the risk of ALF is conflicting with about half of the studies concluding there is no added risk with endplate extravasation and half of the studies reporting opposite conclusions. The purpose of the study is to further stratify the data to determine whether specifically the location and extent of endplate cement extravasation more strongly affect ALF risk in osteoporotic patients following either VP or balloon KP. Retrospective cohort study. University teaching hospital. One hundred and fifty-six cemented levels in 80 patients, treated at a single center between 2008 and 2012 were reviewed. Age, gender, T-score, body mass index, and osteoporosis type (primary or secondary) were recorded. An ALF was defined as a fracture: 1) in a non-cemented vertebra; 2) adjacent to a cemented level; and 3) not due to trauma or malignancy. Location of the cement extravasation (anterior, middle, or posterior third of the vertebral body) and extravasation extent (percentage of the intervertebral disc height occupied by the bolus) were measured. A logistic modeling strategy permitted examining the association between the location and extent of extravasation and the odds of ALF. ALF occurred in 14 of the 52 patients (27%) and 20 of the 98 levels (20.4%) remaining after exclusions. Odds of ALF were 5.9 times higher (95% CI: 1.6 to 21.2, P = 0.008) with extravasation when compared to no leakage. Odds of ALF in a given patient were 22.6 times higher (95% CI: 3.0 to 170.9, P = 0.003) with anterior extravasation when compared to no leakage. Leakage in the middle or posterior thirds and extent of extravasation were not associated with ALF. Limitations of the study include the retrospective study design and small sample size as well as the retrospective implementation of follow-up criteria posing risk of selection bias. Cement endplate extravasation isolated to the anterior third of the vertebral body is associated with is significantly higher odds of ALF after VP or KP in patients with osteoporosis.
Low cost, lightweight fuel cell elements
NASA Technical Reports Server (NTRS)
Kindler, Andrew (Inventor)
2001-01-01
New fuel cell elements for use in liquid feed fuel cells are provided. The elements including biplates and endplates are low in cost, light in weight, and allow high efficiency operation. Electrically conductive elements are also a part of the fuel cell elements.
Closing the Gap: Public Libraries and Senior Learners
ERIC Educational Resources Information Center
Welliver, Hilary
2017-01-01
This executive position paper (EPP) examines the gap in Delaware's public library services to senior citizens engaged in lifelong learning. Re-envisioning the public library as a center that provides support of lifelong learning for the whole individual and improving the quality of life for Kent County's seniors is one approach that may keep…
Haberman Star Teacher Interview as a Predictor of Success in Urban Teacher Preparation
ERIC Educational Resources Information Center
Waddell, Jennifer H.; Marszalek, Jacob M.
2018-01-01
In urban schools, along with skills for effective teaching, successful teachers must also possess values and belief systems conducive to teaching effectively in diverse settings (Becker, Kennedy, & Hundersmarck, 2003; Haberman, 2008; Metzgar & Wu, 2008). As demonstrated in CAEP standard 3, there is a critical need for EPPs to admit…
ERIC Educational Resources Information Center
Friman, Margareta; Nyberg, Claes; Norlander, Torsten
2004-01-01
A descriptive qualitative analysis of in-depth interviews involving seven provincial Soccer Association referees was carried out in order to find out how referees experience threats and aggression directed to soccer referees. The Empirical Phenomenological Psychological method (EPP-method) was used. The analysis resulted in thirty categories which…
Cradle to Gate Life Cycle Assessment of North American Cellulosic Fiberboard Production
Maureen Puettmann; Richard Bergman; Elaine Oneil
2016-01-01
All consumer products have an environmental footprint. Quantifying that footprint has become more common with the advent of Environmental Preferential Purchasing (EPP), an emergent world-wide phenomenon. The forest products industry in particular has been challenged regarding its environmental sustainability. The greatest challenges with respect to practices center on...
CAEP Challenges for a Mid-South U.S. College Teacher Education Program
ERIC Educational Resources Information Center
Moffett, David W.
2016-01-01
What are the challenges faced by a mid-south liberal arts college teacher education program, in its attempt to successfully meet the new Council for the Accreditation of Educator Preparation (CAEP) accreditation requirements? The Investigator studied the Educator Program Provider (EPP) during academic year 2015-2016. The challenges faced by the…
Affordability Constraints in Major Defense Acquisitions
2016-11-01
Fence Inc 1 30-May-2014 4-Oct-2012 4-Nov-2015 32 SSC 5-Jul-2012 33 VH-92A (VXX) 5-Apr-2013 17-Apr-2014 34 FAB -T CPT 26-Oct...Development EPAWSS Eagle Passive/Active Warning and Survivability System EPP Extended Planning Period EPS Enhanced Polar System FAB -T CPT Family of
ERIC Educational Resources Information Center
Campos, Priscilla Bernadette
To ascertain differences in the area of non-intellectual characteristics among senior students and successful practitioners in four paramedical groups, data collected by administering the Edwards Personal Preference Schedule (EPPS) were statistically analyzed. This test, measuring the relative strength of 15 personality needs, was given to 396…
2014-05-21
CAPE CANAVERAL, Fla. – Chirold Epp, the Autonomous Landing and Hazard Avoidance Technology, or ALHAT, project manager, speaks to members of the media inside a facility near the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. Behind Epp is the Project Morpheus prototype lander. Project Morpheus tests NASA’s ALHAT sensors and an engine that runs on liquid oxygen and methane, which are green propellants. These new capabilities could be used in future efforts to deliver cargo to planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Frankie Martin
PLUTO'S SEASONS: NEW PREDICTIONS FOR NEW HORIZONS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Young, L. A.
Since the last Pluto volatile transport models were published in 1996, we have (1) new stellar occultation data from 2002 and 2006-2012 that show roughly twice the pressure as the first definitive occultation from 1988, (2) new information about the surface properties of Pluto, (3) a spacecraft due to arrive at Pluto in 2015, and (4) a new volatile transport model that is rapid enough to allow a large parameter-space search. Such a parameter-space search coarsely constrained by occultation results reveals three broad solutions: a high-thermal inertia, large volatile inventory solution with permanent northern volatiles (PNVs; using the rotational northmore » pole convention); a lower thermal-inertia, smaller volatile inventory solution with exchanges of volatiles between hemispheres and a pressure plateau beyond 2015 (exchange with pressure plateau, EPP); and solutions with still smaller volatile inventories, with exchanges of volatiles between hemispheres and an early collapse of the atmosphere prior to 2015 (exchange with early collapse, EEC). PNV and EPP are favored by stellar occultation data, but EEC cannot yet be definitively ruled out without more atmospheric modeling or additional occultation observations and analysis.« less
Development of a Liquefied Noble Gas Time Projection Chamber
NASA Astrophysics Data System (ADS)
Lesser, Ezra; White, Aaron; Aidala, Christine
2015-10-01
Liquefied noble gas detectors have been used for various applications in recent years for detecting neutrinos, neutrons, photons, and potentially dark matter. The University of Michigan is developing a detector with liquid argon to produce scintillation light and ionization electrons. Our data collection method will allow high-resolution energy measurement and spatial reconstruction of detected particles by using multi-pixel silicon photomultipliers (SiPM) and a cylindrical time projection chamber (TPC) with a multi-wire endplate. We have already designed a liquid argon condenser and purification unit surrounded by an insulating vacuum, constructed circuitry for temperature and pressure sensors, and created software to obtain high-accuracy sensor readouts. The status of detector development will be presented. Funded through the Michigan Memorial Phoenix Project.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Patel, Pretesh R., E-mail: patel073@mc.duke.edu; Yoo, Sua; Broadwater, Gloria
Purpose: To assess the impact of increasing experience with intensity-modulated radiation therapy (IMRT) after extrapleural pneumonectomy (EPP) for malignant pleural mesothelioma (MPM). Methods and Materials: The records of all patients who received IMRT following EPP at Duke University Medical Center between 2005 and 2010 were reviewed. Target volumes included the preoperative extent of the pleural space, chest wall incisions, involved nodal stations, and a boost to close/positive surgical margins if applicable. Patients were typically treated with 9-11 beams with gantry angles, collimator rotations, and beam apertures manually fixed to avoid the contalateral lung and to optimize target coverage. Toxicity wasmore » graded retrospectively using National Cancer Institute common toxicity criteria version 4.0. Target coverage and contralateral lung irradiation were evaluated over time by using linear regression. Local control, disease-free survival, and overall survival rates were estimated using the Kaplan-Meier method. Results: Thirty patients received IMRT following EPP; 21 patients also received systemic chemotherapy. Median follow-up was 15 months. The median dose prescribed to the entire ipsilateral hemithorax was 45 Gy (range, 40-50.4 Gy) with a boost of 8-25 Gy in 9 patients. Median survival was 23.2 months. Two-year local control, disease-free survival, and overall survival rates were 47%, 34%, and 50%, respectively. Increasing experience planning MPM cases was associated with improved coverage of planning target volumes (P=.04). Similarly, mean lung dose (P<.01) and lung V5 (volume receiving 5 Gy or more; P<.01) values decreased with increasing experience. Lung toxicity developed after IMRT in 4 (13%) patients at a median of 2.2 months after RT (three grade 3-4 and one grade 5). Lung toxicity developed in 4 of the initial 15 patients vs none of the last 15 patients treated. Conclusions: With increasing experience, target volume coverage improved and dose to the contralateral lung decreased. Rates of pulmonary toxicity were relatively low. However, both local and distant control rates remained suboptimal.« less
Evaluating the Impact of Expanded Practice Dental Hygienists in Oregon: An Outcomes Assessment.
Bell, Kathryn P; Coplen, Amy E
2016-06-01
Currently the dental hygiene practice model in Oregon includes the Expanded Practice Dental Hygienist (EPDH), which allows dental hygienists with an Expanded Practice Permit (EPP) to provide care to limited access populations without the supervision of a dentist. The number and types of services provided by EPDH practitioners is thus far undocumented. The purpose of this study is to conduct an outcomes assessment of EPDH practitioners in order to quantify the impact, defined by count of services, on the access to care crisis in Oregon. A 16 question confidential survey was developed and approved by the Pacific University institutional review board. The mail-based survey was sent to 181 EPDHs in Oregon in November 2011 (all EPDHs except pilot testers and one author). A second mailing was sent to non-respondents. Data were analyzed using descriptive statistics and chi-square analysis in SPSS. The response rate was 39% (n=71). Approximately 41% (n=29) of the respondents were currently using their EPP to provide care to limited access patients with an additional 21% (n=15) planning to start their own expanded practice. The majority of practicing EPDHs provide care in residential care facilities (n=21) and in school settings (n=13). Of the current practicing EPP holders, 76% practice ≤10 hours per week, and 66% make <$10,000 per year. Total services reported in an average month from all responding EPDH practitioners were: 254 adult prophylaxes, 1,003 child prophylaxes, 106 adult fluorides, 901 child fluorides and 1,994 fluoride varnishes, among many other preventive procedures. To a limited extent, the amount and type of services provided by EPDHs has now been quantified, and EPDHs are making an impact on the access to care crisis in Oregon. Continued outcomes assessment is needed to further quantify the impact of EPDHs. Copyright © 2016 The American Dental Hygienists’ Association.
Evaluating the impact of expanded practice dental hygienists in Oregon: an outcomes assessment.
Bell, Kathryn P; Coplen, Amy E
2015-02-01
Currently the dental hygiene practice model in Oregon includes the Expanded Practice Dental Hygienist (EPDH), which allows dental hygienists with an Expanded Practice Permit (EPP) to provide care to limited access populations without the supervision of a dentist. The number and types of services provided by EPDH practitioners is thus far undocumented. The purpose of this study is to conduct an outcomes assessment of EPDH practitioners in order to quantify the impact, defined by count of services, on the access to care crisis in Oregon. A 16 question confidential survey was developed and approved by the Pacific University institutional review board. The mail-based survey was sent to 181 EPDHs in Oregon in November 2011 (all EPDHs except pilot testers and one author). A second mailing was sent to non-respondents. Data were analyzed using descriptive statistics and chi-square analysis in SPSS. The response rate was 39% (n = 71). Approximately 41% (n = 29) of the respondents were currently using their EPP to provide care to limited access patients with an additional 21% (n = 15) planning to start their own expanded practice. The majority of practicing EPDHs provide care in residential care facilities (n = 21) and in school settings (n=13). Of the current practicing EPP holders, 76% practice ≤ 10 hours per week, and 66% make < $10,000 per year. Total services reported in an average month from all responding EPDH practitioners were: 254 adult prophylaxes, 1,003 child prophylaxes, 106 adult fluorides, 901 child fluorides and 1,994 fluoride varnishes, among many other preventive procedures. To a limited extent, the amount and type of services provided by EPDHs has now been quantified, and EPDHs are making an impact on the access to care crisis in Oregon. Continued outcomes assessment is needed to further quantify the impact of EPDHs. Copyright © 2015 The American Dental Hygienists’ Association.
de Souza, Elaine Dantas; Moralez-Silva, Emmanuel; Valdes, Talita Alvarenga; Cortiço Corrêa Rodrigues, Vera Lúcia
2017-01-01
Colonial waterbirds such as herons, egrets and spoonbills exhibit ecological characteristics that could have promoted the evolution of conspecific brood parasitism and extra-pair copulation. However, an adequate characterization of the genetic mating systems of this avian group has been hindered by the lack of samples of elusive candidate parents which precluded conducting conventional parentage allocation tests. Here, we investigate the genetic mating system of the invasive cattle egret using hematophagous insects contained in fake eggs to collect blood from incubating adults in a wild breeding colony. We tested a protocol with a previously unused Neotropical Triatominae, Panstrongylus megistus, obtained blood samples from males and females in 31 nests built on trees, drew blood from 89 nestlings at those nests, and genotyped all samples at 14 microsatellite loci, including six new species-specific loci. We comparatively addressed the performance of parentage allocation versus kinship classification of nestlings to infer the genetic mating system of cattle egrets. In line with previous behavioral observations, we found evidence in support of a non-monogamous genetic mating system, including extra-pair paternity (EPP) and conspecific brood parasitism (CBP). Parentage allocation tests detected a higher percentage of nests with alternative reproductive tactics (EPP: 61.7%; CBP: 64.5%) than the kinship classification method (EPP: 50.0%; CBP: 43.3%). Overall, these results indicate that rates of alternative reproductive tactics inferred in the absence of parental genetic information could be underestimated and should be interpreted with caution. This study highlights the importance of incorporating samples from candidate parents to adequately determine the genetic mating system of a species. We expand knowledge on the reproductive tactics of colonial waterbirds, contributing novel data on the genetic mating system of the cattle egret, valuable for the design of management strategies for this invasive bird. PMID:28854191
Miño, Carolina Isabel; de Souza, Elaine Dantas; Moralez-Silva, Emmanuel; Valdes, Talita Alvarenga; Cortiço Corrêa Rodrigues, Vera Lúcia; Del Lama, Sílvia Nassif
2017-01-01
Colonial waterbirds such as herons, egrets and spoonbills exhibit ecological characteristics that could have promoted the evolution of conspecific brood parasitism and extra-pair copulation. However, an adequate characterization of the genetic mating systems of this avian group has been hindered by the lack of samples of elusive candidate parents which precluded conducting conventional parentage allocation tests. Here, we investigate the genetic mating system of the invasive cattle egret using hematophagous insects contained in fake eggs to collect blood from incubating adults in a wild breeding colony. We tested a protocol with a previously unused Neotropical Triatominae, Panstrongylus megistus, obtained blood samples from males and females in 31 nests built on trees, drew blood from 89 nestlings at those nests, and genotyped all samples at 14 microsatellite loci, including six new species-specific loci. We comparatively addressed the performance of parentage allocation versus kinship classification of nestlings to infer the genetic mating system of cattle egrets. In line with previous behavioral observations, we found evidence in support of a non-monogamous genetic mating system, including extra-pair paternity (EPP) and conspecific brood parasitism (CBP). Parentage allocation tests detected a higher percentage of nests with alternative reproductive tactics (EPP: 61.7%; CBP: 64.5%) than the kinship classification method (EPP: 50.0%; CBP: 43.3%). Overall, these results indicate that rates of alternative reproductive tactics inferred in the absence of parental genetic information could be underestimated and should be interpreted with caution. This study highlights the importance of incorporating samples from candidate parents to adequately determine the genetic mating system of a species. We expand knowledge on the reproductive tactics of colonial waterbirds, contributing novel data on the genetic mating system of the cattle egret, valuable for the design of management strategies for this invasive bird.
Fox, Matthew P; Brooks, Daniel; Kuhn, Louise; Aldrovandi, Grace; Sinkala, Moses; Kankasa, Chipepo; Mwiya, Mwiya; Horsburgh, Robert; Thea, Donald M
2008-05-01
In developing countries, where mother-to-child transmission of HIV through breast-feeding is common, little is known about the impact of postpartum transmission on child survival. This study assessed whether children infected postpartum have longer survival from time of infection versus those infected during gestation or delivery. We used a prospective cohort study to analyze data from 213 HIV-infected children enrolled in a breast-feeding intervention trial in Lusaka, Zambia (2001 to 2004). We compared mortality 1 year after HIV infection in children stratified by age of infection: 0 to 3 days (intrauterine [IU] group), 4 to 40 days (intrapartum/early postpartum [IP/EPP] group), and >40 days (postpartum [PP] group). A total of 61, 71, and 81 children were infected in the IU, IP/EPP, and PP groups, respectively. Children with intrauterine or intrapartum/early postpartum transmission had higher mortality over the first 12 months after infection than children with postpartum transmission (P = 0.001 and P = 0.006, respectively); no differences were detected between children with intrauterine and intrapartum/early postpartum transmission. Nearly 20% of the IU and IP/EPP groups died by 100 days after infection, whereas nearly 10% of the PP group had died by this time. After adjusting for birth weight, maternal CD4 cell count, breast-feeding, and maternal death, children infected postpartum had one quarter the mortality rate (hazard ratio [HR] = 0.27, 95% confidence interval [CI]: 0.15 to 0.50) of those infected in utero. Stopping breast-feeding increased mortality in infected children (HR = 3.1, 95% CI: 1.8 to 5.3). This study demonstrates a survival benefit among children infected postpartum versus children infected during pregnancy or delivery and a benefit to increased breast-feeding duration among infected children. Testing children for HIV early may provide a means to allow for earlier intervention.
Faizan, Ahmad; Goel, Vijay K; Biyani, Ashok; Garfin, Steven R; Bono, Christopher M
2012-03-01
Studies delineating the adjacent level effect of single level disc replacement systems have been reported in literature. The aim of this study was to compare the adjacent level biomechanics of bi-level disc replacement, bi-level fusion and a construct having adjoining level disc replacement and fusion system. In total, biomechanics of four models- intact, bi level disc replacement, bi level fusion and fusion plus disc replacement at adjoining levels- was studied to gain insight into the effects of various instrumentation systems on cranial and caudal adjacent levels using finite element analysis (73.6N+varying moment). The bi-level fusion models are more than twice as stiff as compared to the intact model during flexion-extension, lateral bending and axial rotation. Bi-level disc replacement model required moments lower than intact model (1.5Nm). Fusion plus disc replacement model required moment 10-25% more than intact model, except in extension. Adjacent level motions, facet loads and endplate stresses increased substantially in the bi-level fusion model. On the other hand, adjacent level motions, facet loads and endplate stresses were similar to intact for the bi-level disc replacement model. For the fusion plus disc replacement model, adjacent level motions, facet loads and endplate stresses were closer to intact model rather than the bi-level fusion model, except in extension. Based on our finite element analysis, fusion plus disc replacement procedure has less severe biomechanical effects on adjacent levels when compared to bi-level fusion procedure. Bi-level disc replacement procedure did not have any adverse mechanical effects on adjacent levels. Copyright © 2011 Elsevier Ltd. All rights reserved.
Wang, Kuan; Deng, Zhen; Wang, Hui-Hao; Li, Zheng-Yan; Niu, Wen-Xin; Chen, Bo; Zhang, Ming-Cai; Yuan, Wei-An; Zhan, Hong-Sheng
2017-05-25
To analyze the relationship between position of head, cervical curvature type and associated cervical balance parameters in a neutral looking-forward posture. Cervical lateral X-rays of 60 patients with cervical spondylosis were selected from January to December 2015. There were 22 males and 38 females with an average age of (35.5±10.9) years old. The measured parameters included cervical curvature type, McGregor slope, C2 lower end plate slope, T1 slope, center of gravity to C7 sagittal vertical offset (CG-C7 SVA), and C2 to C7 sagittal vertical offset (C2-C7 SVA). The parameters were analyzed using Spearman correlation. The cervical curvature type was significantly correlated with C2 lower endplate slope, C0-C2 angle (total degree of C2 lower endplate slope plus McGregor slope), CG-C7 SVA and T1 slope ( P <0.05), but it was not significantly correlated McGregor slope ( P >0.05). C2 lower endplate slope and C2-C7 SVA (r=0.87) were significantly ( P <0.05) correlated with CG-C7 SVA ( P <0.05). There was certain some relationship among position of head, cervical curvature type and associated cervical balance parameters in a neutral looking-forward posture. The center of gravity of the head would backwards shift following faced upward. A position of extension with posterior-shifting of the head would suggest that it may be accompanied with a relatively normal lordosis of the cervical spine. Some patients with abnormal curvature showed slightly bended head in the natural posture. Health education toward these people would be meaningful to restore the balance of their neck.
Expression of miR-625 and Fas in cervical vertebral cartilage endplate.
Zhan, Beilei; Zhan, Yan; Wang, Wei; Zhan, Yunzhong; Liu, Bingsheng
2018-01-01
The aim of the present study was to assess miR-625 and Fas expression in normal and degenerative cervical cartilage endplate (CEP) tissues. Following biof-informatics analysis, the Fas gene was predicted to be one of the targets of miR-625. Quantitative PCR (qPCR) and western blotting were used to detect miR-625 and Fas expression in normal and degenerative CEP. A luciferase reporter assay was used to identify whether miR-625 could directly target the 3' untranslated region (3'-UTR) of Fas. Lentiviral overexpression and/or inhibition vectors of miR-625 (pre-miR-625)/antigomiR-625 were constructed to determine whether overexpression or inhibition of miR-625 could affect Fas and B-cell lymphoma 2 (Bcl-2) expression in cartilaginous endplate cells (CECs) and tissues. qPCR analysis demonstrated that miR-625 expression in degenerative CEP was significantly lower than in normal CEP tissue, while the production of Fas in degenerated CEP was significantly higher. Results from western blotting also showed a significant increase in Fas expression in degenerative CEP. miR-625 can bind directly to the 3'-UTR of the Fas gene. However, this inhibition was attenuated by a target mutation in the miR-625-binding site of the 3'-UTR of Fas mRNA. In addition, following transfection of CECs with pre-miR-625 and antigomiR-625, expression of Fas significantly decreased and increased, respectively, and Bcl-2 expression was upregulated and downregulated, respectively. Upregulation of miR-625 can inhibit Fas expression and further affect Bcl-2 expression in CEP degeneration, suggesting that miR-625-mediated inhibition of the Fas gene is important in cervical degeneration.
Pumberger, Matthias; Hughes, Alexander P; Girardi, Federico P; Gogia, Jaspaul; Kotwal, Suhel Y; Thaler, Christoph; Sama, Andrew A
2012-12-01
Cadaveric study. The purpose of this study was to assess the influence of surgical experience on the efficiency of lumbar discectomy in open transforaminal lumbar interbody fusion. There is limited knowledge about the efficiency of discectomy among surgeons. As a first study, we are evaluating the effect of surgical experience on it. Manual and powered discectomies were randomized and performed by 3 attending spine surgeons and 2 clinical spine fellows. Each discectomy procedure was analyzed for the area of complete endplate preparation, total elapsed time, and number of instrument passes. The surface area of discectomy at each endplate was measured utilizing digital imaging and the appropriate software. For the purpose of the analysis, the superior and the inferior endplates were divided into ipsilateral and contralateral halves, and each half was further divided into ventral and dorsal quadrants. Each quadrant was analyzed in a blinded manner by 2 observers. A total of 40 discectomies were performed on 9 fresh-frozen cadaveric torsos between the levels T12 and S1. A powered discectomy device was used in levels 9 and 11 by the attendings. Manual discectomy was performed in 11 levels by the spine fellows and 9 by the spine attendings. No significant difference was observed between the spine fellows and spine attendings when the manual instruments were used (P = 0.924). However, the spine attending surgeon group had a significantly increased total area of discectomy compared with the fellows (P = 0.003). No significant difference was observed between the groups when instrument passes or the total elapsed time were compared either utilizing the manual or the powered technique. Our results demonstrate that a satisfactory discectomy may be performed by surgeons with relatively less surgical experience in the transforaminal approach using a powered discectomy device.
Hou, Yu; Yao, Qi; Zhang, Genai; Ding, Lixiang; Huang, Hui
2018-01-01
Osteoporotic vertebral compression fracture, always accompanied with pain and height loss of vertebral body, has a significant negative impact on life quality of patients. Vertebroplasty or kyphoplasty is minimal invasive techniques to reconstruct the vertebral height and prevent further collapse of the fractured vertebrae by injecting polymethylmethacrylate into vertebral body. However, recompression of polymethylmethacrylate augmented vertebrae with significant vertebral height loss and aggressive local kyphotic was observed frequently after VP or KP. The purpose of this study was to investigate the effect of polymethylmethacrylate distribution on recompression of the vertebral body after vertebroplasty or kyphoplasty surgery for osteoporotic vertebral compression fracture. A total of 281 patients who were diagnosed with vertebral compression fracture (T5-L5) from June 2014 to June 2016 and underwent vertebroplasty or kyphoplasty by polymethylmethacrylate were retrospectively analyzed. The X-ray films at 1 day and 12 months after surgery were compared to evaluate the recompression of operated vertebral body. Patients were divided into those without recompression (non-recompression group) and those with recompression (recompression group). Polymethylmethacrylate distribution pattern, including location and relationship to endplates, was compared between the two groups by lateral X-ray film. Multivariate logistic regression analysis was performed to assess the potential risk factors associated with polymethylmethacrylate distribution for recompression. One hundred and six (37.7%) patients experienced recompression after surgery during the follow-up period. The polymethylmethacrylate distributed in the middle of vertebral body showed significant differences between two groups. In non-recompression group, the polymethylmethacrylate in the middle portion of vertebral body were closer to endplates than that in the recompression group (upper: t = 31.41, p<0.001; lower: t = 12.19, p<0.001). The higher percentage of the height of polymethylmethacrylate in the middle portion of vertebral body indicates the lower risk of recompression (odds ratio [OR]<0.01, p<0.001). The recompression group and non-recompression group showed significant difference in "contacted" polymethylmethacrylate distribution pattern (polymethylmethacrylate contacted to the both upper/lower endplates) (χ2 = 66.23, p<0.001). The vertebra with a "contacted" polymethylmethacrylate distribution pattern has lower risk of recompression (OR = 0.09, p<0.001). Either more polymethylmethacrylate in the middle portion of vertebral body or "contacted" polymethylmethacrylate distribution pattern had a significantly less incidence of recompression. The findings indicated that the control of polymethylmethacrylate distribution during surgery may reduce the risks of recompression after vertebroplasty or kyphoplasty.
Yao, Qi; Zhang, Genai; Ding, Lixiang; Huang, Hui
2018-01-01
Background Osteoporotic vertebral compression fracture, always accompanied with pain and height loss of vertebral body, has a significant negative impact on life quality of patients. Vertebroplasty or kyphoplasty is minimal invasive techniques to reconstruct the vertebral height and prevent further collapse of the fractured vertebrae by injecting polymethylmethacrylate into vertebral body. However, recompression of polymethylmethacrylate augmented vertebrae with significant vertebral height loss and aggressive local kyphotic was observed frequently after VP or KP. The purpose of this study was to investigate the effect of polymethylmethacrylate distribution on recompression of the vertebral body after vertebroplasty or kyphoplasty surgery for osteoporotic vertebral compression fracture. Methods A total of 281 patients who were diagnosed with vertebral compression fracture (T5-L5) from June 2014 to June 2016 and underwent vertebroplasty or kyphoplasty by polymethylmethacrylate were retrospectively analyzed. The X-ray films at 1 day and 12 months after surgery were compared to evaluate the recompression of operated vertebral body. Patients were divided into those without recompression (non-recompression group) and those with recompression (recompression group). Polymethylmethacrylate distribution pattern, including location and relationship to endplates, was compared between the two groups by lateral X-ray film. Multivariate logistic regression analysis was performed to assess the potential risk factors associated with polymethylmethacrylate distribution for recompression. Results One hundred and six (37.7%) patients experienced recompression after surgery during the follow-up period. The polymethylmethacrylate distributed in the middle of vertebral body showed significant differences between two groups. In non-recompression group, the polymethylmethacrylate in the middle portion of vertebral body were closer to endplates than that in the recompression group (upper: t = 31.41, p<0.001; lower: t = 12.19, p<0.001). The higher percentage of the height of polymethylmethacrylate in the middle portion of vertebral body indicates the lower risk of recompression (odds ratio [OR]<0.01, p<0.001). The recompression group and non-recompression group showed significant difference in “contacted” polymethylmethacrylate distribution pattern (polymethylmethacrylate contacted to the both upper/lower endplates) (χ2 = 66.23, p<0.001). The vertebra with a “contacted” polymethylmethacrylate distribution pattern has lower risk of recompression (OR = 0.09, p<0.001). Conclusions Either more polymethylmethacrylate in the middle portion of vertebral body or “contacted” polymethylmethacrylate distribution pattern had a significantly less incidence of recompression. The findings indicated that the control of polymethylmethacrylate distribution during surgery may reduce the risks of recompression after vertebroplasty or kyphoplasty. PMID:29856859
Santafé, Manel M; Garcia, Neus; Tomàs, Marta; Obis, Teresa; Lanuza, Maria A; Besalduch, Nuria; Tomàs, Josep
2014-02-21
We conducted an electrophysiological study of the functional link between the tropomyosin-related kinase B (trkB) receptor signaling mechanism and serine-threonine kinases, both protein kinase C (PKC) and protein kinase A (PKA). We describe their coordinated role in transmitter release at the neuromuscular junction (NMJ) of the Levator auris longus muscle of the adult mouse. The trkB receptor normally seems to be coupled to stimulate ACh release because inhibiting the trkB receptor with K-252a results in a significant reduction in the size of EPPs. We found that the intracellular PKC pathway can operate as in basal conditions (to potentiate ACh release) without the involvement of the trkB receptor function, although the trkB pathway needs an operative PKC pathway if it is to couple to the release mechanism and potentiate it. To actively stimulate PKA (which also results in ACh release potentiation), the operativity of trkB is a necessary condition, and one effect of trkB may be PKA stimulation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Current Status of the Congenital Myasthenic Syndromes
Engel, Andrew G.
2011-01-01
Congenital myasthenic syndromes (CMS) are heterogeneous disorders in which the safety margin of neuromuscular transmission is compromised by one or more specific mechanisms. Clinical, electrophysiologic, and morphologic studies have paved the way for detecting CMS-related mutations in proteins residing in the nerve terminal, the synaptic basal lamina, and in the postsynaptic region of the motor endplate. The disease proteins identified to date include choline acetyltransferase (ChAT), the endplate species of acetylcholinesterase (AChE), β2-laminin, the acetylcholine receptor (AChR), rapsyn, plectin, Nav1.4, the muscle specific protein kinase (MuSK), agrin, downstream of tyrosine kinase 7 (Dok-7), and glutamine-fructose-6-phosphate transaminase 1 (GFPT1). Myasthenic syndromes associated with centronuclear myopathies were recently recognized. Analysis of properties of expressed mutant proteins contributed to finding improved therapy for most CMS. Despite these advances, the molecular basis of some phenotypically characterized CMS remains elusive. Moreover, other types of CMS and disease genes likely exist and await discovery. PMID:22104196
Land, B R; Harris, W V; Salpeter, E E; Salpeter, M M
1984-01-01
In previous papers we studied the rising phase of a miniature endplate current (MEPC) to derive diffusion and forward rate constants controlling acetylcholine (AcCho) in the intact neuromuscular junction. The present study derives similar values (but with smaller error ranges) for these constants by including experimental results from the falling phase of the MEPC. We find diffusion to be 4 X 10(-6) cm2 s-1, slightly slower than free diffusion, forward binding to be 3.3 X 10(7) M-1 s-1, and the distance from an average release site to the nearest exit from the cleft to be 1.6 micron. We also estimate the back reaction rates. From our values we can accurately describe the shape of MEPCs under different conditions of receptor and esterase concentration. Since we suggest that unbinding is slower than isomerization, we further predict that there should be several short "closing flickers" during the total open time for an AcCho-ligated receptor channel. PMID:6584895
Thermal Behaviour of Beams with Slant End-Plate Connection Subjected to Nonsymmetric Gravity Load
Osman, Mohd Hanim; Talebi, Elnaz
2014-01-01
Research on the steel structures with confining of axial expansion in fixed beams has been quite intensive in the past decade. It is well established that the thermal behaviour has a key influence on steel structural behaviours. This paper describes mechanical behaviour of beams with bolted slant end-plate connection with nonsymmetric gravity load, subjected to temperature increase. Furthermore, the performance of slant connections of beams in steel moment frame structures in the elastic field is investigated. The proposed model proved that this flexible connection system could successfully decrease the extra thermal induced axial force by both of the friction force dissipation among two faces of slant connection and a small upward movement on the slant plane. The applicability of primary assumption is illustrated. The results from the proposed model are examined within various slant angles, thermal and friction factors. It can be concluded that higher thermal conditions are tolerable when slanting connection is used. PMID:24587720
Thermal behaviour of beams with slant end-plate connection subjected to nonsymmetric gravity load.
Zahmatkesh, Farshad; Osman, Mohd Hanim; Talebi, Elnaz
2014-01-01
Research on the steel structures with confining of axial expansion in fixed beams has been quite intensive in the past decade. It is well established that the thermal behaviour has a key influence on steel structural behaviours. This paper describes mechanical behaviour of beams with bolted slant end-plate connection with nonsymmetric gravity load, subjected to temperature increase. Furthermore, the performance of slant connections of beams in steel moment frame structures in the elastic field is investigated. The proposed model proved that this flexible connection system could successfully decrease the extra thermal induced axial force by both of the friction force dissipation among two faces of slant connection and a small upward movement on the slant plane. The applicability of primary assumption is illustrated. The results from the proposed model are examined within various slant angles, thermal and friction factors. It can be concluded that higher thermal conditions are tolerable when slanting connection is used.
NASA Astrophysics Data System (ADS)
Bhattacharya, Purba; Bhattacharya, Deb Sankar; Mukhopadhyay, Supratik; Majumdar, Nayana; Bhattacharya, Sudeb; Colas, Paul; Attié, David
2018-02-01
The R&D activities for the linear collider TPC (LC-TPC) are currently working on the adoption of the micro pattern devices for the gaseous amplification stage. Several beam tests have been carried out at DESY with a 5 GeV electron beam in a 1 T superconducting magnet. We worked on a large prototype TPC with an end-plate that was built, for the first time, using seven resistive bulk Micromegas modules. During experiments, reduced signal sensitivity was observed at the boundary of these modules. Electrostatic field distortion near the module boundaries was considered to be the possible major reason behind these observations. In the present work, we will explore this hypothesis through numerical simulation. Our aim has been to understand the origin of distortions observed close to the edges of the test beam modules and to explore the possibility of using the Garfield simulation framework for investigating a phenomenon as complex as distortion.
ERIC Educational Resources Information Center
O'Donoghue, Grainne; Doody, Catherine; Cusack, Tara
2011-01-01
The purpose of this study was to examine physiotherapy students' perceptions of current education content of entry-level physiotherapy programmes in terms of physical activity (PA) and exercise promotion and prescription (EPP). Sixty-two physiotherapy students from three Irish Universities participated. Three Structured Group Feedback Sessions…
On Social Psychology and Human Nature: An Interview with Roy Baumeister
ERIC Educational Resources Information Center
Lawrence, Natalie Kerr
2008-01-01
Roy F. Baumeister currently holds the Eppes Eminent Professorship in the Department of Psychology at Florida State University. He received his PhD in social psychology from Princeton in 1978 working under Edward E. Jones. After a postdoctoral fellowship in sociology at Berkeley, he spent 23 years on the faculty at Case Western Reserve University,…
Education for Parenthood: Eighth Graders Change Child Rearing Attitudes.
ERIC Educational Resources Information Center
Richett, Diana; Towns, Kathryn
This study examined the effects of an Education for Parenthood Program (EPP) on the childrearing attitudes of eighth grade students. Two eighth grade classes were randomly selected from five sections at a middle school in south central Pennsylvania. One of the classes (both of which were approximatley 60% male and 70% black) was randomly assigned…
Educational Research and Evidence-Based Policy: The Mixed-Method Approach of the EPPE Project
ERIC Educational Resources Information Center
Siraj-Blatchford, I.
2006-01-01
In a review of the challenges to progress in providing social research evidence that might usefully inform policy, Oakley (2004) argues strongly that the "paradigm divide" between qualitative and quantitative research communities continues to constitute a major problem. Oakley refers to a number of recent critiques of what is seen as "misplaced…
ERIC Educational Resources Information Center
Cole, Elaine J.; Fieselman, Laura
2013-01-01
Purpose: The purpose of this paper is to design a community-based social marketing (CBSM) campaign to foster sustainable behavior change in paper reduction, commingled recycling, and purchasing environmentally preferred products (EPP) with faculty and staff at Pacific University Oregon. Design/methodology/approach: A CBSM campaign was developed…
Learning in the Home and at School: How Working Class Children "Succeed against the Odds"
ERIC Educational Resources Information Center
Siraj-Blatchford, Iram
2010-01-01
This paper presents data collected in individual case studies that aimed to investigate children and their families who succeeded against the usual "odds" of disadvantage. Funded as an extension of EPPE 3-11 by the Cabinet Office for the Equalities Review, the study focused particularly closely upon the performance of disadvantaged…
ERIC Educational Resources Information Center
Egan, Bridget A.
2009-01-01
Recent developments in early childhood education in the UK and other parts of Europe have emphasised the importance of dialogue between adults and children. In the UK, the EPPE project paid particular attention to the role of extended child-centred conversations ("sustained shared thinking"--Sylva et al. 2003) as an important element or…
ERIC Educational Resources Information Center
Data Quality Campaign, 2016
2016-01-01
For educator preparation programs (EPPs) to produce effective teachers, they must engage in a process of continuous improvement using timely, high-quality information about the performance of their respective graduates in the classroom as measured by student outcomes. While states have the capacity to provide this information through their…
The effect of anions on bound acetylcholine in frog sartorius muscle.
Ceccarelli, B; Molenaar, P C; Oen, B S; Polak, R L; Torri-Tarelli, F; van Kempen, G T
1989-01-01
1. Frog sartorius muscles were treated with an irreversible cholinesterase inhibitor and then incubated in isotonic potassium propionate solution (isotonic KPr). Total and bound, presumably vesicular, acetylcholine (ACh) in the tissue and ACh in the medium were assayed by mass fragmentography, miniature end-plate potentials (MEPPs) were recorded and the end-plates were investigated by electron microscopy. 2. Incubation in isotonic KPr for 30 min stimulated ACh release and concomitantly decreased total and bound ACh. Nerve stimulation for 30 min by trains of impulses (0.1 s trains of 100 Hz, 1 train s-1) in normal-potassium propionate-containing solution had the same effects. 3. When the tissue was incubated in normal-K+ Ringer solution for 3 h, following chemical or electric stimulation, bound ACh recovered to about 75% of the initial value, provided that Cl- ions were present in the medium. In the presence of propionate instead of Cl- ions almost no recovery of bound ACh took place. There was also recovery of bound ACh in the presence of either NO3- or gluconate ions. In NO3- it was the same as in Cl-, but in gluconate it was less than found in Cl- -containing medium. 4. Recovery of total ACh, in contrast to bound ACh, took place even in the presence of propionate ions, showing that extracellular Cl- is not required for the synthesis of ACh. 5. In terminals recovered in normal Ringer solution, many synaptic vesicles were found, but terminals 'recovered' in propionate solution were depleted of vesicles. 6. From these and other results it is concluded that the recycling of synaptic vesicles normally requires the presence of extracellular chloride. Images Fig. 1 Fig. 2 PMID:2789283
Paxton, E Scott; Moorman, Claude T; Chehab, Eric L; Barnes, Ronnie P; Warren, Russell F; Brophy, Robert H
2010-11-01
Hyperconcavity of the lumbar spine has been found in a disproportionate percentage of college football lineman evaluated at the National Football League (NFL) Combine compared with age-matched controls. College football linemen with hyperconcavity of the lumbar spine are more likely to play in the NFL and to have a longer career in professional football. Cohort study; Level of evidence, 3. Ninety three linemen from the 1992 and 1993 NFL Combines with hyperconcavity of the lumbar spine were compared with 191 linemen from the same combines without these changes in the lumbar spine. The percentage of athletes who played at least 1 game for an NFL team and the average length of career was calculated for both groups. In addition, the length of career for players with these changes was compared with those of matched controls based on other injuries and surgeries, year drafted, and round drafted. There was no difference in the likelihood of playing professional football between linemen with lumbar spine changes (54 of 93 [58%]) and those without (101 of 191 [53%]) (P = .41). There was no significant difference between the 2 groups in length of career in terms of years played, games played, or games started. Hyperconcavity of the lumbar spine does not appear to have any effect on the potential professional American football careers of college football linemen entering the NFL. Endplate changes on radiographs are not a significant screening tool for elite American football linemen. Further study of larger populations is needed to definitively answer whether these adaptive changes in the lumbar spine have any clinical relevance to these athletes.
Fuel cell elements with improved water handling capacity
NASA Technical Reports Server (NTRS)
Kindler, Andrew (Inventor); Lee, Albany (Inventor)
2001-01-01
New fuel cell components for use in liquid feed fuel cell systems are provided. The components include biplates and endplates, having a hydrophilic surface and allow high efficiency operation. Conductive elements and a wicking device also form a part of the fuel cell components of the invention.
ERIC Educational Resources Information Center
Boediono; And Others
The Educational Policy and Planning (EPP) Project assists the Indonesian Ministry of Education and Culture (MOEC) in establishing an information system to improve policy analysis and formulation. There are five elements of the project strategy: increase the ability of MOEC staff to create and use information for use in policy research, strengthen…
"Would You Like to Tidy up Now?" An Analysis of Adult Questioning in the English Foundation Stage
ERIC Educational Resources Information Center
Siraj-Blatchford, Iram; Manni, Laura
2008-01-01
This study provides an extension of analysis concerned with adult questioning carried out in the Researching Effective Pedagogy in the Early Years (REPEY) study. The REPEY study drew on robust quantitative data provided by the Effective Provision of Pre-School Education (EPPE) project to identify the particular pedagogical strategies being applied…
USA PATRIOT Improvement and Reauthorization Act of 2005 (H.R. 3199): A Brief Look
2005-12-09
sales of ephedrine, pseudoephedrine and phenylpropanolamine (EPP) products, 21 U.S.C. 830(d); (b) requires that the products be available only "behind the...counter" and that purchasers of products containing more than 60 mg of pseudoephedrine present a photo Id and sign a log book, 21 U.S.C. 830(e); (c
Applying Multimedia Learning Theories to the Redesign of Residence Life Online Training Modules
ERIC Educational Resources Information Center
Kaliher, Licinia Barrueco
2010-01-01
The purpose of this Executive Position Paper (EPP) is to develop a model for improving the online training modules utilized by a mid-Atlantic Residence Life department. The complexity of the Residence Life staff positions, coupled with demands from other university departments and the need to provide as much information as possible, resulted in an…
The molecular defect of ferrochelatase in a patient with erythropoietic protoporphyria.
Nakahashi, Y; Fujita, H; Taketani, S; Ishida, N; Kappas, A; Sassa, S
1992-01-01
The molecular basis of an inherited defect of ferrochelatase in a patient with erythropoietic protoporphyria (EPP) was investigated. Ferrochelatase is the terminal enzyme in the heme biosynthetic pathway and catalyzes the insertion of ferrous iron into protoporphyrin IX to form heme. In Epstein-Barr virus-transformed lymphoblastoid cells from a proband with EPP, enzyme activity, an immunochemically quantifiable protein, and mRNA content of ferrochelatase were about one-half the normal level. In contrast, the rate of transcription of ferrochelatase mRNA in the proband's cells was normal, suggesting that decreased ferrochelatase mRNA is due to an unstable transcript. cDNA clones encoding ferrochelatase in the proband, isolated by amplification using the polymerase chain reaction, were found to be classified either into those encoding the normal protein or into those encoding an abnormal protein that lacked exon 2 of the ferrochelatase gene, indicating that the proband is heterozygous for the ferrochelatase defect. Genomic DNA analysis revealed that the abnormal allele had a point mutation, C----T, near the acceptor site of intron 1. This point mutation appears to be responsible for the post-transcriptional splicing abnormality resulting in an aberrant transcript of ferrochelatase in this patient. Images PMID:1729699
Surgery for malignant pleural mesothelioma: an international guidelines review
Cardillo, Giuseppe; Zirafa, Carmelina Cristina; Carleo, Francesco; Facciolo, Francesco; Fontanini, Gabriella; Mutti, Luciano; Melfi, Franca
2018-01-01
Currently there is no universally accepted surgical therapy for malignant pleural mesothelioma (MPM). The goal of surgery in this dismal disease is a macroscopic complete resection (MCR) and there are two types of intervention with a curative intent. At one side, there is the extrapleural pneumonectomy (EPP) which consists in an en-bloc resection of the lung, pleura, pericardium and diaphragm and at the other side, there is pleurectomy/decortication (P/D) a lung-sparing surgery. Initially, EPP was considered the only surgical option with a curative aim, but during the decades P/D have acquired a role of increasing importance in MPM therapy. Several randomized prospective trials are required to establish the best strategy in the treatment of pleural mesothelioma. Although which is the best surgical option remains unclear, the International Mesothelioma Interest Group (IMIG), recently have stated that the type of surgery depends on clinical factors and on individual surgical judgment and expertise. Moreover, according to the current evidence, the surgery should be performed in high-volume centres within multimodality protocols. The aim of this study is to examine the currently available international guidelines in the surgical diagnosis and treatment of MPM. PMID:29507797
A Monte-Carlo Benchmark of TRIPOLI-4® and MCNP on ITER neutronics
NASA Astrophysics Data System (ADS)
Blanchet, David; Pénéliau, Yannick; Eschbach, Romain; Fontaine, Bruno; Cantone, Bruno; Ferlet, Marc; Gauthier, Eric; Guillon, Christophe; Letellier, Laurent; Proust, Maxime; Mota, Fernando; Palermo, Iole; Rios, Luis; Guern, Frédéric Le; Kocan, Martin; Reichle, Roger
2017-09-01
Radiation protection and shielding studies are often based on the extensive use of 3D Monte-Carlo neutron and photon transport simulations. ITER organization hence recommends the use of MCNP-5 code (version 1.60), in association with the FENDL-2.1 neutron cross section data library, specifically dedicated to fusion applications. The MCNP reference model of the ITER tokamak, the `C-lite', is being continuously developed and improved. This article proposes to develop an alternative model, equivalent to the 'C-lite', but for the Monte-Carlo code TRIPOLI-4®. A benchmark study is defined to test this new model. Since one of the most critical areas for ITER neutronics analysis concerns the assessment of radiation levels and Shutdown Dose Rates (SDDR) behind the Equatorial Port Plugs (EPP), the benchmark is conducted to compare the neutron flux through the EPP. This problem is quite challenging with regard to the complex geometry and considering the important neutron flux attenuation ranging from 1014 down to 108 n•cm-2•s-1. Such code-to-code comparison provides independent validation of the Monte-Carlo simulations, improving the confidence in neutronic results.
CephFS: a new generation storage platform for Australian high energy physics
NASA Astrophysics Data System (ADS)
Borges, G.; Crosby, S.; Boland, L.
2017-10-01
This paper presents an implementation of a Ceph file system (CephFS) use case at the ARC Center of Excellence for Particle Physics at the Terascale (CoEPP). CoEPP’s CephFS provides a posix-like file system on top of a Ceph RADOS object store, deployed on commodity hardware and without single points of failure. By delivering a unique file system namespace at different CoEPP centres spread across Australia, local HEP researchers can store, process and share data independently of their geographical locations. CephFS is also used as the back-end file system for a WLCG ATLAS user area at the Australian Tier-2. Dedicated SRM and XROOTD services, deployed on top of CoEPP’s CephFS, integrates it in ATLAS data distributed operations. This setup, while allowing Australian HEP researchers to trigger data movement via ATLAS grid tools, also enables local posix-like read access providing greater control to scientists of their data flows. In this article we will present details on CoEPP’s Ceph/CephFS implementation and report performance I/O metrics collected during the testing/tuning phase of the system.
Ondersma, Steven J; Martin, Joanne; Fortson, Beverly; Whitaker, Daniel J; Self-Brown, Shannon; Beatty, Jessica; Loree, Amy; Bard, David; Chaffin, Mark
2017-11-01
Early home visitation (EHV) for child maltreatment prevention is widely adopted but has received inconsistent empirical support. Supplementation with interactive software may facilitate attention to major risk factors and use of evidence-based approaches. We developed eight 20-min computer-delivered modules for use by mothers during the course of EHV. These modules were tested in a randomized trial in which 413 mothers were assigned to software-supplemented e-Parenting Program ( ePP), services as usual (SAU), or community referral conditions, with evaluation at 6 and 12 months. Outcomes included satisfaction, working alliance, EHV retention, child maltreatment, and child maltreatment risk factors. The software was well-received overall. At the 6-month follow-up, working alliance ratings were higher in the ePP condition relative to the SAU condition (Cohen's d = .36, p < .01), with no differences at 12 months. There were no between-group differences in maltreatment or major risk factors at either time point. Despite good acceptability and feasibility, these findings provide limited support for use of this software within EHV. These findings contribute to the mixed results seen across different models of EHV for child maltreatment prevention.
Characterization of Urinary Phthalate Metabolites Among Custodians
Cavallari, Jennifer M.; Simcox, Nancy J.; Wakai, Sara; Lu, Chensheng; Garza, Jennifer L.; Cherniack, Martin
2015-01-01
Phthalates, a ubiquitous class of chemicals found in consumer, personal care, and cleaning products, have been linked to adverse health effects. Our goal was to characterize urinary phthalate metabolite concentrations and to identify work and nonwork sources among custodians using traditional cleaning chemicals and ‘green’ or environmentally preferable products (EPP). Sixty-eight custodians provided four urine samples on a workday (first void, before shift, end of shift, and before bedtime) and trained observers recorded cleaning tasks and types of products used (traditional, EPP, or disinfectant) hourly over the work shifts. Questionnaires were used to assess personal care product use. Four different phthalate metabolites [monoethyl phthalate (MEP), monomethyl phthalate (MMP), mono (2-ethylhexyl) phthalate (MEHP), and monobenzyl phthalate (MBzP)] were quantified using liquid chromatography mass spectrometry. Geometric means (GM) and 95% confidence intervals (95% CI) were calculated for creatinine-adjusted urinary phthalate concentrations. Mixed effects univariate and multivariate modeling, using a random intercept for each individual, was performed to identify predictors of phthalate metabolites including demographics, workplace factors, and personal care product use. Creatinine-adjusted urinary concentrations [GM (95% CI)] of MEP, MMP, MEHP, and MBzP were 107 (91.0–126), 2.69 (2.18–3.30), 6.93 (6.00–7.99), 8.79 (7.84–9.86) µg g−1, respectively. An increasing trend in phthalate concentrations from before to after shift was not observed. Creatinine-adjusted urinary MEP was significantly associated with frequency of traditional cleaning chemical intensity in the multivariate model after adjusting for potential confounding by demographics, workplace factors, and personal care product use. While numerous demographics, workplace factors, and personal care products were statistically significant univariate predictors of MMP, MEHP, and MBzP, few associations persisted in multivariate models. In summary, among this population of custodians, we identified both occupational and nonoccupational predictors of phthalate exposures. Identification of phthalates as ingredients in cleaning chemicals and consumer products would allow workers and consumers to avoid phthalate exposure. PMID:26240196
Jiang, Zengxin; Lu, Wei; Zeng, Qingmin; Li, Defang; Ding, Lei; Wu, Jingping
2018-04-16
Diabetes mellitus (DM) is an important factor in intervertebral disc degeneration (IDD). Apoptosis of cartilage endplate (CEP) cells is one of the initiators of IDD. However, the effects of high glucose on CEP cells are still unknown. Therefore, we conducted the present study to evaluate the effects of high glucose on CEP cells and to identify the mechanisms of those effects. Rat CEP cells were isolated and cultured in 10% foetal bovine serum (FBS, normal control) or high-glucose medium (10% FBS + 0.1 M glucose or 10% FBS + 0.2 M glucose, experimental conditions) for 1 or 3 days. In addition, CEP cells were treated with 0.2 M glucose for 3 days in the presence or absence of alpha-lipoic acid (ALA, 0.15 M). Flow cytometry was performed to identify and quantify the degree of apoptosis. The expression of reactive oxygen species (ROS) was assessed by flow cytometry, and mitochondrial damage (mitochondrial membrane potential) was assessed by fluorescence microscopy. Furthermore, the expression levels of cleaved caspase-3, cleaved caspase-9, Bcl-2, Bax, and cytochrome c were evaluated by Western blotting. High glucose significantly increased apoptosis and ROS accumulation in CEP cells in a dose- and time-dependent manner. Meanwhile, a disrupted mitochondrial membrane potential was detected in rat CEP cells cultured in the two high glucose concentrations. Incubating in high glucose enhanced the expression levels of cleaved caspase-3, cleaved caspase-9, Bax, and cytochrome c but decreased the level of the anti-apoptotic protein Bcl-2. ALA inhibited the expression of cleaved caspase-3, cleaved caspase-9, Bax, and cytochrome c but enhanced the expression of Bcl-2. ALA also prevented disruption of the mitochondrial membrane potential in CEP cells. This study demonstrates that high glucose-induced excessive reactive oxygen species promote mitochondrial damage, thus causing apoptosis in rat CEP cells in a dose- and time-dependent manner. ALA could prevent mitochondrial damage and apoptosis caused by high glucose in CEP cells. The results suggest that appropriate blood glucose control may be the key to preventing IDD in diabetic patients. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.
Schwann Cells in Neuromuscular Junction Formation and Maintenance.
Barik, Arnab; Li, Lei; Sathyamurthy, Anupama; Xiong, Wen-Cheng; Mei, Lin
2016-09-21
The neuromuscular junction (NMJ) is a tripartite synapse that is formed by motor nerve terminals, postjunctional muscle membranes, and terminal Schwann cells (TSCs) that cover the nerve-muscle contact. NMJ formation requires intimate communications among the three different components. Unlike nerve-muscle interaction, which has been well characterized, less is known about the role of SCs in NMJ formation and maintenance. We show that SCs in mice lead nerve terminals to prepatterned AChRs. Ablating SCs at E8.5 (i.e., prior nerve arrival at the clusters) had little effect on aneural AChR clusters at E13.5, suggesting that SCs may not be necessary for aneural clusters. SC ablation at E12.5, a time when phrenic nerves approach muscle fibers, resulted in smaller and fewer nerve-induced AChR clusters; however, SC ablation at E15.5 reduced AChR cluster size but had no effect on cluster density, suggesting that SCs are involved in AChR cluster maturation. Miniature endplate potential amplitude, but not frequency, was reduced when SCs were ablated at E15.5, suggesting that postsynaptic alterations may occur ahead of presynaptic deficits. Finally, ablation of SCs at P30, after NMJ maturation, led to NMJ fragmentation and neuromuscular transmission deficits. Miniature endplate potential amplitude was reduced 3 d after SC ablation, but both amplitude and frequency were reduced 6 d after. Together, these results indicate that SCs are not only required for NMJ formation, but also necessary for its maintenance; and postsynaptic function and structure appeared to be more sensitive to SC ablation. Neuromuscular junctions (NMJs) are critical for survival and daily functioning. Defects in NMJ formation during development or maintenance in adulthood result in debilitating neuromuscular disorders. The role of Schwann cells (SCs) in NMJ formation and maintenance was not well understood. We genetically ablated SCs during development and after NMJ formation to investigate the consequences of the ablation. This study reveals a critical role of SCs in NMJ formation as well as maintenance. Copyright © 2016 the authors 0270-6474/16/369770-12$15.00/0.
Zhang, Bao-cheng; Liu, Hai-bo; Cai, Xian-hua; Wang, Zhi-hua; Xu, Feng; Kang, Hui; Ding, Ran; Luo, Xiao-qing
2015-09-22
The transoral atlantoaxial reduction plate (TARP) fixation has been introduced to achieve reduction, decompression, fixation and fusion of C1-C2 through a transoral-only approach. However, it may also be associated with potential disadvantages, including dysphagia and load shielding of the bone graft. To prevent potential disadvantages related to TARP fixation, a novel transoral atlantoaxial fusion cage with integrated plate (Cage + Plate) device for stabilization of the C1-C2 segment is designed. The aims of the present study were to compare the biomechanical differences between Cage + Plate device and Cage + TARP device for the treatment of basilar invagination (BI) with irreducible atlantoaxial dislocation (IAAD). A detailed, nonlinear finite element model (FEM) of the intact upper cervical spine had been developed and validated. Then a FEM of an unstable BI model treated with Cage + Plate fixation, was compared to that with Cage + TARP fixation. All models were subjected to vertical load with pure moments in flexion, extension, lateral bending and axial rotation. Range of motion (ROM) of C1-C2 segment and maximum von Mises Stress of the C2 endplate and bone graft were quantified for the two devices. Both devices significantly reduced ROM compared with the intact state. In comparison with the Cage + Plate model, the Cage + TARP model reduced the ROM by 82.5 %, 46.2 %, 10.0 % and 74.3 % in flexion, extension, lateral bending, and axial rotation. The Cage + Plate model showed a higher increase stresses on C2 endplate and bone graft than the Cage + TARP model in all motions. Our results indicate that the novel Cage + Plate device may provide lower biomechanical stability than the Cage + TARP device in flexion, extension, and axial rotation, however, it may reduce stress shielding of the bone graft for successful fusion and minimize the risk of postoperative dysphagia. Clinical trials are now required to validate the reproducibility and advantages of our findings using this anchored cage for the treatment of BI with IAAD.
Fuel Cell Vehicle Fleet and Hydrogen Infrastructure at Hickam Air Force Base
2009-04-27
there has been no evidence of busbar or endplate corrosion in the manifold region. The crossover leak was the result of a failed humidification device...leak that develops within the humidifier can lead to a combustible gas mixture entering the fuel cell stack. This humidification device has been
Effect of a nicotinic acetylcholine receptor agonists and antagonists on motor function in mice
USDA-ARS?s Scientific Manuscript database
Nicotinic acetylcholine receptors (nAChR) are ligand-gated cation channels found throughout the body, and serve to mediate diverse physiological functions. Muscle-type nAChR located in the motor endplate region of muscle fibers play an integral role in muscle contraction and thus motor function. The...
Minatel, Elaine; Neto, Humberto Santo; Marques, Maria Julia
2003-11-01
The pattern of innervation of the vertebrate neuromuscular junction is established during early development, when junctions go from multiple to single innervation in the phenomenon of synapse elimination, suggesting that changes at the molecular level in the postsynaptic cell lead to the removal of nerve terminals. The mdx mouse is deficient in dystrophin and associated proteins that are part of the postsynaptic cytoskeleton. We used rhodamine-alpha-bungarotoxin and anti-neurofilament IgG-FITC to stain acetylcholine receptors and nerve terminals of the sternomastoid muscle during postnatal development in mdx and control C57BL/10 mice. Using fluorescence confocal microscopy, we observed that, 7 days after birth, 86.7% of the endplates of mdx mice were monoinnervated (n = 200) compared with 41.4% in control mice (n = 200). By the end of the second postnatal week, all endplates were innervated singly (100% mdx and 94.7% controls, n = 200 per group). These results show that dystrophic fibers achieve single innervation earlier, perhaps because dystrophin or a normal cytoskeletal complex is implicated in this phenomenon.
Sex assessment using measurements of the first lumbar vertebra.
Zheng, Wen Xu; Cheng, Fu Bo; Cheng, Kai Liang; Tian, Yong; Lai, Ying; Zhang, Wen Song; Zheng, Ya Juan; Li, You Qiong
2012-06-10
Sex determination is a vital part of the medico-legal system but can be difficult in cases where the integrity of the body has been compromised. The purpose of this study was to develop a technique for sex assessment from measurements of the first lumber vertebrate. Twenty-nine linear measurements and five ratios were collected from 113 Chinese adult males and 97 Chinese adult females using digital three-dimensional anthropometry methods. By using discriminant analysis, we found that 23 linear measurements and two ratios identified sexual dimorphism (P<0.01), with predictive accuracy ranging from 57.1% to 86.6%. Using a stepwise method of discriminant function analysis, we found three dimensions predicted sex with 88.6% accuracy: (a) upper end-plate width (EPWu), (b) left pedicle height (PHl), and (c) middle end-plate depth (EPDm). This study shows that a single first lumber vertebra can be used for this purpose, and that the discriminant equation will help forensic determination of sex in the Chinese population. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Rajasekaran, S; Kanna, Rishi Mugesh; Senthil, Natesan; Raveendran, Muthuraja; Cheung, Kenneth M C; Chan, Danny; Subramaniam, Sakthikanal; Shetty, Ajoy Prasad
2013-10-01
Although the influence of genetics on the process of disc degeneration is well recognized, in recently published studies, there is a wide variation in the race and selection criteria for such study populations. More importantly, the radiographic features of disc degeneration that are selected to represent the disc degeneration phenotype are variable in these studies. The study presented here evaluates the association between single nucleotide polymorphisms (SNPs) of candidate genes and three distinct radiographic features that can be defined as the degenerative disc disease (DDD) phenotype. The study objectives were to examine the allelic diversity of 58 SNPs related to 35 candidate genes related to lumbar DDD, to evaluate the association in a hitherto unevaluated ethnic Indian population that represents more than one-sixth of the world population, and to analyze how genetic associations can vary in the same study subjects with the choice of phenotype. A cross-sectional, case-control study of an ethnic Indian population was carried out. Fifty-eight SNPs in 35 potential candidate genes were evaluated in 342 subjects and the associations were analyzed against three highly specific markers for DDD, namely disc degeneration by Pfirrmann grading, end-plate damage evaluated by total end-plate damage score, and annular tears evaluated by disc herniations and hyperintense zones. Genotyping of cases and controls was performed on a genome-wide SNP array to identify potential associated disease loci. The results from the genome-wide SNP array were then used to facilitate SNP selection and genotype validation was conducted using Sequenom-based genotyping. Eleven of the 58 SNPs provided evidence of association with one of the phenotypes. For annular tears, rs1042631 SNP of AGC1 and rs467691 SNP of ADAMTS5 were highly significantly associated (p<.01) and SNPs in NGFB, IL1B, IL18RAP, and MMP10 were also significantly associated (p<.05). The rs4076018 SNP of NGFB was highly significant (p<.01) and rs2292657 SNP of GLI1 was significantly (p<.05) correlated to disc degeneration. For end-plate damage, the rs2252070 SNP of MMP 13 showed a significant association (p<.05). Previously associated genes such as COL 9, SKT, CHST 3, CILP, IGFR, SOXp, BMP, MMP 2-12, ADH2, IL1RN, and COX2 were not significantly associated and new associations (NGFB and GLI1) were identified. The validity of all the associations was found to be phenotype dependent. For the first time, genetic associations with DDD have been performed in an Indian population. Apart from identifying new associations, the highlight of the study was that in the same study population with DDD, SNP associations completely changed when different radiographic features were used to define the DDD phenotype. Our study results therefore indicate that standardization of the phenotypes chosen to study the genetics of disc degeneration is essential and should be strongly considered before planning genetic association studies. Copyright © 2013 Elsevier Inc. All rights reserved.
Cultivating a Growth Mindset in Students at a High-Achieving High School
ERIC Educational Resources Information Center
Fegley, Alan D.
2010-01-01
The purpose of this EPP is to develop a plan for changing the mindset of a large number of Haddonfield Memorial High School (HMHS) students from a fixed mindset to a growth mindset. HMHS is by most conventional measures a high performing school. Typically 100% of the students graduate with 96% of the students attending two or four year colleges…
A Mid-Level Dental Provider in Oregon: Dental hygienists' perceptions.
Coplen, Amy E; Bell, Kathryn; Aamodt, Gail L; Ironside, Lynn
2017-10-01
Purpose: Many states are exploring alternative provider models and examining the role of the dental hygienist to address access to care challenges as the United States continues to face increasing demands for oral healthcare services. The purpose of this study was to assess dental hygienists' opinions in the state of Oregon regarding the current limitations of dental hygienists' scope of practice, perceived need for a mid-level provider in Oregon, and personal interest in becoming a mid-level provider. Methods: In December 2013 a survey was mailed to a sample of 1,231 dental hygienists registered in Oregon representing 30% of the licentiates. All licentiates holding expanded practice permits (EPP) were included in the sample (n=351). The following categories were included in the 32-question survey: scope of practice, mid-level provider, current practice, and demographics. Results: A total of 440 surveys were returned for a response rate of 36%. Of the EPP holders, 51% responded to the survey. Over half of respondents (59%) believe that a mid-level provider is needed in the state. Respondents holding membership in the American Dental Hygienists' Association, as well as EPP holders, were significantly more likely to respond that a mid-level dental provider was needed in the state (p<0.0001). Ninety-one percent (n=400) of respondents agreed or strongly agreed that if a mid-level provider was introduced in Oregon, the new provider should be a registered dental hygienist model. Forty-three percent (n=186) of respondents were interested in becoming mid-level providers and 47% (n=203) of respondents believed that the minimum education for a mid-level provider should be a bachelor's degree. The majority, 74% (n=137), of those interested in becoming a mid-level provider indicated a preference in completing their education through online teaching combined with a clinical internship. Conclusion: There is strong support from dental hygienists in Oregon that a need exists for a mid-level dental provider and that this provider model should be dental hygiene based. Individuals interested in developing a curriculum for a mid-level provider should consider including online teaching components with a clinical internship component. Copyright © 2017 The American Dental Hygienists’ Association.
Selection of Drought Tolerant Maize Hybrids Using Path Coefficient Analysis and Selection Index.
Dao, Abdalla; Sanou, Jacob; V S Traore, Edgar; Gracen, Vernon; Danquah, Eric Y
2017-01-01
In drought-prone environments, direct selection for yield is not adequate because of the variable environment and genotype x environment interaction. Therefore, the use of secondary traits in addition to yield has been suggested. The relative usefulness of secondary traits as indirect selection criteria for maize grain yield is determined by the magnitudes of their genetic variance, heritability and genetic correlation with the grain yield. Forty eight testcross hybrids derived from lines with different genetic background and geographical origins plus 7 checks were evaluated in both well-watered and water-stressed conditions over two years for grain yield and secondary traits to determine the most appropriate secondary traits and select drought tolerant hybrids. Study found that broad-sense heritability of grain yield and Ear Per Plant (EPP) increased under drought stress. Ear aspect (EASP) and ear height (EHT) had larger correlation coefficients and direct effect on grain yield but in opposite direction, negative and positive respectively. Traits like, EPP, Tassel Size (TS) and Plant Recovery (PR) contributed to increase yield via EASP by a large negative indirect effect. Under drought stress, EHT had positive and high direct effect and negative indirect effect via plant height on grain yield indicating that the ratio between ear and plant heights (R-EPH) was associated to grain yield. Path coefficient analysis showed that traits EPP, TS, PR, EASP, R-EPH were important secondary traits in the present experiment. These traits were used in a selection index to classify hybrids according to their performance under drought. The selection procedure included also a Relative Decrease in Yield (RDY) index. Some secondary traits reported as significant selection criteria for selection under drought stress were not finally established in the present study. This is because the relationship between grain and secondary traits can be affected by various factors including germplasm, environment and applied statistical analysis. Therefore, different traits and selection procedure should be applied in the selection process of drought tolerant genotypes for diverse genetic materials and growing conditions.
The Extensional Rheology of Non-Newtonian Materials
NASA Technical Reports Server (NTRS)
Spiegelberg, Stephen H.; McKinley, Gareth H.
1996-01-01
The evolution of the transient extensional stresses in dilute and semi-dilute viscoelastic polymer solutions are measured with a filament stretching rheometer of a design similar to that first introduced by Sridhar, et al. The solutions are polystyrene-based (PS) Boger fluids that are stretched at constant strain rates ranging from 0.6 less than or equal to epsilon(0) less than or equal to 4s(exp -1) and to Hencky strains of epsilon greater than 4. The test fluids all strain harden and Trouton ratios exceeding 1000 are obtained at high strains. The experimental data strain hardens at lower strain levels than predicted by bead-spring FENE models. In addition to measuring the transient tensile stress growth, we also monitor the decay of the tensile viscoelastic stress difference in the fluid column following cessation of uniaxial elongation as a function of the total imposed Hencky strain and the strain rate. The extensional stresses initially decay very rapidly upon cessation of uniaxial elongation followed by a slower viscoelastic relaxation, and deviate significantly from FENE relaxation predictions. The relaxation at long times t is greater than or equal to 5 s, is compromised by gravitational draining leading to non-uniform filament profiles. For the most elastic fluids, partial decohension of the fluid filament from the endplates of the rheometer is observed in tests conducted at high strain rates. This elastic instability is initiated near the rigid endplate fixtures of the device and it results in the progressive breakup of the fluid column into individual threads or 'fibrils' with a regular azimuthal spacing. These fibrils elongate and bifurcate as the fluid sample is elongated further. Flow visualization experiments using a modified stretching device show that the instability develops as a consequence of an axisymmetry-breaking meniscus instability in the nonhomogeneous region of highly deformed fluid near the rigid endplate.
Tian, L; Prior, C; Dempster, J; Marshall, I G
1997-11-01
1. The neuronal nicotinic receptor antagonists hexamethonium and methyllycaconitine (MLA) have been used to study the putative prejunctional nicotinic ACh receptors (AChRs) mediating a negative-feedback control of ACh release from motor nerve terminals in voltage-clamped rat phrenic nerve/ hemidiaphragm preparations. 2. Hexamethonium (200 microM), but not MLA (0.4-2.0 microM), decreased the time constant of decay of both endplate currents (e.p.cs) and miniature endplate currents (m.e.p.cs), indicating endplate ion channel block with hexamethonium. However, driving function analysis and reconvolution of e.p.cs and m.e.p.cs indicated that this ion channel block did not compromise the analysis of e.p.c. quantal content. 3. At low frequencies of stimulation (0.5-2 Hz), hexamethonium (200 microM) and MLA (2.0 microM) increased e.p.c. quantal content by 30-40%. At high frequencies (50-150 Hz) neither compound affected e.p.c. quantal content. All effects on quantal content were paralleled by changes in the size of the pool of quanta available for release. 4. The low frequency augmentation of e.p.c. quantal content by hexamethonium was absent when extracellular [Ca2+] was lowered from 2.0 to 0.5 mM. 5. At the concentrations studied, MLA and hexamethonium produced a small (10-20%) decrease in the peak amplitude of m.e.p.cs. 6. Neither apamin (100 nM) nor charybdotoxin (80 nM) had effects on spontaneous or nerve evoked current amplitudes at any frequency of stimulation. Thus the ability of nicotinic antagonists to augment e.p.c. quantal content is not due to inhibition of Ca(2+)-activated K(+)-channels. 7. We suggest that hexamethonium and MLA increase evoked ACh release by blocking prejunctional nicotinic AChRs. These receptors exert a negative feedback control over evoked ACh release and are probably of the alpha-bungarotoxin-insensitive neuronal type.
Tian, >Lijun; Prior, Chris; Dempster, John; Marshall, Ian G
1997-01-01
The neuronal nicotinic receptor antagonists hexamethonium and methyllycaconitine (MLA) have been used to study the putative prejunctional nicotinic ACh receptors (AChRs) mediating a negative-feedback control of ACh release from motor nerve terminals in voltage-clamped rat phrenic nerve/hemidiaphragm preparations. Hexamethonium (200 μM), but not MLA (0.4–2.0 μM), decreased the time constant of decay of both endplate currents (e.p.cs) and miniature endplate currents (m.e.p.cs), indicating endplate ion channel block with hexamethonium. However, driving function analysis and reconvolution of e.p.cs and m.e.p.cs indicated that this ion channel block did not compromise the analysis of e.p.c. quantal content. At low frequencies of stimulation (0.5–2 Hz), hexamethonium (200 μM) and MLA (2.0 μM) increased e.p.c. quantal content by 30–40%. At high frequencies (50–150 Hz) neither compound affected e.p.c. quantal content. All effects on quantal content were paralleled by changes in the size of the pool of quanta available for release. The low frequency augmentation of e.p.c. quantal content by hexamethonium was absent when extracellular [Ca2+] was lowered from 2.0 to 0.5 mM. At the concentrations studied, MLA and hexamethonium produced a small (10–20%) decrease in the peak amplitude of m.e.p.cs. Neither apamin (100 nM) nor charybdotoxin (80 nM) had effects on spontaneous or nerve evoked current amplitudes at any frequency of stimulation. Thus the ability of nicotinic antagonists to augment e.p.c. quantal content is not due to inhibition of Ca2+-activated K+-channels. We suggest that hexamethonium and MLA increase evoked ACh release by blocking prejunctional nicotinic AChRs. These receptors exert a negative feedback control over evoked ACh release and are probably of the α-bungarotoxin-insensitive neuronal type. PMID:9401765
Dudli, Stefan; Liebenberg, Ellen; Magnitsky, Sergey; Miller, Steve; Demir-Deviren, Sibel; Lotz, Jeffrey C
2016-08-01
Modic type I change (MC1) are vertebral bone marrow lesions adjacent to degenerated discs that are specific for discogenic low back pain. The etiopathogenesis is unknown, but occult discitis, in particular with Propionibacteria acnes (P. acnes), has been suggested as a possible etiology. If true, antibiotic therapy should be considered for patients with MC1. However, this hypothesis is controversial. While some studies report up to 40% infection rate in herniated discs, others fail to detect infected discs and attribute reports of positive cultures to contamination during sampling procedure. Irrespective of the clinical controversy, whether it is biologically plausible for P. acnes to cause MC1 has never been investigated. Therefore, the objective of this study was to test if P. acnes can proliferate within discs and cause reactive changes in the adjacent bone marrow. P. acnes was aseptically isolated from a symptomatic human L4/5 disc with MC1 and injected into rat tail discs. We demonstrate proliferation of P. acnes and up-regulation of IL-1 and IL-6 within three days of inoculation. At day-7, disc degeneration was apparent along with fibrotic endplate erosion. TNF-α immunoreactivity was enhanced within the effected endplates along with cellular infiltrates. The bone marrow appeared normal. At day-14, endplates and trabecular bone close to the disc were almost completely resorbed and fibrotic tissue extended into the bone marrow. T-cells and TNF-α immunoreactivity were identified at the disc/marrow junction. On MRI, bone marrow showed MC1-like changes. In conclusion, P. acnes proliferate within the disc, induce degeneration, and cause MC1-like changes in the adjacent bone marrow. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1447-1455, 2016. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.
Kanna, Rishi M; Shetty, Ajoy Prasad; Rajasekaran, S
2014-02-01
Existing research on lumbar disc degeneration has remained inconclusive regarding its etiology, pathogenesis, symptomatology, prevention, and management. Degenerative disc disease (DDD) and disc prolapse (DP) are common diseases affecting the lumbar discs. Although they manifest clinically differently, existing studies on disc degeneration have included patients with both these features, leading to wide variations in observations. The possible relationship or disaffect between DDD and DP is not fully evaluated. To analyze the patterns of lumbar disc degeneration in patients with chronic back pain and DDD and those with acute DP. Prospective, magnetic resonance imaging-based radiological study. Two groups of patients (aged 20-50 years) were prospectively studied. Group 1 included patients requiring a single level microdiscectomy for acute DP. Group 2 included patients with chronic low back pain and DDD. Discs were assessed by magnetic resonance imaging through Pfirmann grading, Schmorl nodes, Modic changes, and the total end-plate damage score for all the five lumbar discs. Group 1 (DP) had 91 patients and group 2 (DDD) had 133 patients. DP and DDD patients differed significantly in the number, extent, and severity of degeneration. DDD patients had a significantly higher number of degenerated discs than DP patients (p<.000). The incidence of multilevel and pan-lumbar degeneration was also significantly higher in DDD group. The pattern of degeneration also differed in both the groups. DDD patients had predominant upper lumbar involvement, whereas DP patients had mainly lower lumbar degeneration. Modic changes were more common in DP patients, especially at the prolapsed level. Modic changes were present in 37% of prolapsed levels compared with 9.9% of normal discs (p<.00). The total end-plate damage score had a positive correlation with disc degeneration in both the groups. Further the mean total end-plate damage score at prolapsed level was also significantly higher. The results suggest that patients with disc prolapse, and those with back pain with DDD are clinically and radiologically different groups of patients with varying patterns, severity, and extent of disc degeneration. This is the first study in literature to compare and identify significant differences in these two commonly encountered patient groups. In patients with single-level DP, the majority of the other discs are nondegenerate, the lower lumbar spine is predominantly involved and the end-plate damage is higher. Patients with back pain and DDD have larger number of degenerate discs, early multilevel degeneration, and predominant upper lumbar degeneration. The knowledge that these two groups of patients are different clinically and radiologically is critical for our improved understanding of the disease and for future studies on disc degeneration and disc prolapse. Copyright © 2014 Elsevier Inc. All rights reserved.
Modic Type 1 Changes: Detection Performance of Fat-Suppressed Fluid-Sensitive MRI Sequences.
Finkenstaedt, Tim; Del Grande, Filippo; Bolog, Nicolae; Ulrich, Nils; Tok, Sina; Kolokythas, Orpheus; Steurer, Johann; Andreisek, Gustav; Winklhofer, Sebastian
2018-02-01
To assess the performance of fat-suppressed fluid-sensitive MRI sequences compared to T1-weighted (T1w) / T2w sequences for the detection of Modic 1 end-plate changes on lumbar spine MRI. Sagittal T1w, T2w, and fat-suppressed fluid-sensitive MRI images of 100 consecutive patients (consequently 500 vertebral segments; 52 female, mean age 74 ± 7.4 years; 48 male, mean age 71 ± 6.3 years) were retrospectively evaluated. We recorded the presence (yes/no) and extension (i. e., Likert-scale of height, volume, and end-plate extension) of Modic I changes in T1w/T2w sequences and compared the results to fat-suppressed fluid-sensitive sequences (McNemar/Wilcoxon-signed-rank test). Fat-suppressed fluid-sensitive sequences revealed significantly more Modic I changes compared to T1w/T2w sequences (156 vs. 93 segments, respectively; p < 0.001). The extension of Modic I changes in fat-suppressed fluid-sensitive sequences was significantly larger compared to T1w/T2w sequences (height: 2.53 ± 0.82 vs. 2.27 ± 0.79, volume: 2.35 ± 0.76 vs. 2.1 ± 0.65, end-plate: 2.46 ± 0.76 vs. 2.19 ± 0.81), (p < 0.05). Modic I changes that were only visible in fat-suppressed fluid-sensitive sequences but not in T1w/T2w sequences were significantly smaller compared to Modic I changes that were also visible in T1w/T2w sequences (p < 0.05). In conclusion, fat-suppressed fluid-sensitive MRI sequences revealed significantly more Modic I end-plate changes and demonstrated a greater extent compared to standard T1w/T2w imaging. · When the Modic classification was defined in 1988, T2w sequences were heavily T2-weighted and thus virtually fat-suppressed.. · Nowadays, the bright fat signal in T2w images masks edema-like changes.. · The conventional definition of Modic I changes is not fully applicable anymore.. · Fat-suppressed fluid-sensitive MRI sequences revealed more/greater extent of Modic I changes.. · Finkenstaedt T, Del Grande F, Bolog N et al. Modic Type 1 Changes: Detection Performance of Fat-Suppressed Fluid-Sensitive MRI Sequences. Fortschr Röntgenstr 2018; 190: 152 - 160. © Georg Thieme Verlag KG Stuttgart · New York.
AGARD Bulletin Technical Programme 1986.
1985-08-01
basic research findings are being exploited by the pharmaceutical industry to develop new performance enhancing drugs with limited side effects and to... effects of nutrients on performance will also be considered. SHORT COURSE ( K Subject to final approval by the National Delegates Board at its Fall...coordinated with the AVP. WORKING GROUP The EPP will initiate Working Group-02 on "Near Water Propagation Effects and Modem System Adaptation". This
ERIC Educational Resources Information Center
Connell, Noreen
2007-01-01
For more than a century, a succession of New York City (NYC) mayors have claimed that they were reducing administrative overhead in the school system and driving more resources to instruction. These claims have been dutifully reported by the press with rarely any effort to verify them. For the last 50 years, the salaries of teachers were increased…
EPPS16: nuclear parton distributions with LHC data.
Eskola, Kari J; Paakkinen, Petja; Paukkunen, Hannu; Salgado, Carlos A
2017-01-01
We introduce a global analysis of collinearly factorized nuclear parton distribution functions (PDFs) including, for the first time, data constraints from LHC proton-lead collisions. In comparison to our previous analysis, EPS09, where data only from charged-lepton-nucleus deep inelastic scattering (DIS), Drell-Yan (DY) dilepton production in proton-nucleus collisions and inclusive pion production in deuteron-nucleus collisions were the input, we now increase the variety of data constraints to cover also neutrino-nucleus DIS and low-mass DY production in pion-nucleus collisions. The new LHC data significantly extend the kinematic reach of the data constraints. We now allow much more freedom for the flavor dependence of nuclear effects than in other currently available analyses. As a result, especially the uncertainty estimates are more objective flavor by flavor. The neutrino DIS plays a pivotal role in obtaining a mutually consistent behavior for both up and down valence quarks, and the LHC dijet data clearly constrain gluons at large momentum fraction. Mainly for insufficient statistics, the pion-nucleus DY and heavy-gauge-boson production in proton-lead collisions impose less visible constraints. The outcome - a new set of next-to-leading order nuclear PDFs called EPPS16 - is made available for applications in high-energy nuclear collisions.
Semeniuk, Patricia; Mildon, Barbara; Purkis, Mary Ellen; Thorne, Sally; Wejr, Patricia
2010-05-01
This paper describes the conceptual structure and organizational framework of the Educator Pathway Project (EPP), which is a unique collaborative capacity-building project creating infrastructure for integrating nursing practice learning and development throughout the service and education sectors in British Columbia. Since 2005, two major health authorities, two universities and the provincial nurses' bargaining association have been engaged in an intensive and dynamic partnership to conceptualize and fundamentally change intersectoral directions and possibilities. This unique initiative has required considerable investment and commitment among all partner organizations, resulting in a clear, shared vision of systemwide support of nursing. With the EPP now in its final year of funding, we are beginning to document its elements and interpret its significant impact on nurses and their workplaces across the regions. In this paper, we describe the overall program design, explain the collaborative partnership mechanisms through which we have been implementing the project and articulate a range of processes through which we are working together to enact significant system-level adjustments aimed at a genuine practice-education continuum. As part of sustaining a strong nursing workforce, we believe that nursing practice and education leaders across Canada are ready to employ this kind of creative approach towards realizing our common goals.
Heritability of female extra-pair paternity rate in song sparrows (Melospiza melodia)
Reid, Jane M.; Arcese, Peter; Sardell, Rebecca J.; Keller, Lukas F.
2011-01-01
The forces driving the evolution of extra-pair reproduction in socially monogamous animals remain widely debated and unresolved. One key hypothesis is that female extra-pair reproduction evolves through indirect genetic benefits, reflecting increased additive genetic value of extra-pair offspring. Such evolution requires that a female's propensity to produce offspring that are sired by an extra-pair male is heritable. However, additive genetic variance and heritability in female extra-pair paternity (EPP) rate have not been quantified, precluding accurate estimation of the force of indirect selection. Sixteen years of comprehensive paternity and pedigree data from socially monogamous but genetically polygynandrous song sparrows (Melospiza melodia) showed significant additive genetic variance and heritability in the proportion of a female's offspring that was sired by an extra-pair male, constituting major components of the genetic architecture required for extra-pair reproduction to evolve through indirect additive genetic benefits. However, estimated heritabilities were moderately small (0.12 and 0.18 on the observed and underlying latent scales, respectively). The force of selection on extra-pair reproduction through indirect additive genetic benefits may consequently be relatively weak. However, the additive genetic variance and non-zero heritability observed in female EPP rate allow for multiple further genetic mechanisms to drive and constrain mating system evolution. PMID:20980302
Wright, David J; Brouwer, Lyanne; Mannarelli, Maria-Elena; Burke, Terry; Komdeur, Jan; Richardson, David S
2016-01-01
The prevalence and significance of precopulatory mate choice remains keenly debated. The major histocompatibility complex (MHC) plays a key role in vertebrate adaptive immunity, and variation at the MHC influences individual survival. Although MHC-dependent mate choice has been documented in certain species, many other studies find no such pattern. This may be, at least in part, because in natural systems constraints may reduce the choices available to individuals and prevent full expression of underlying preferences. We used translocations to previously unoccupied islands to experimentally reduce constraints on female social mate choice in the Seychelles warbler ( Acrocephalus sechellensis ), a species in which patterns of MHC-dependent extrapair paternity (EPP), but not social mate choice, have been observed. We find no evidence of MHC-dependent social mate choice in the new populations. Instead, we find that older males and males with more microsatellite heterozygosity are more likely to have successfully paired. Our data cannot resolve whether these patterns in pairing were due to male-male competition or female choice. However, our research does suggest that female Seychelles warblers do not choose social mates using MHC class I to increase fitness. It may also indicate that the MHC-dependent EPP observed in the source population is probably due to mechanisms other than female precopulatory mate choice based on MHC cues.
Huai, Junling; Zhang, Xinyu; Li, Jialong; Ma, Tingting; Zha, Ping; Jing, Yanjun; Lin, Rongcheng
2018-05-02
Plants continuously monitor environmental conditions (such as light and temperature) and adjust their growth and development accordingly. The transcription factor PHYTOCHROME-INTERACTING FACTOR4 (PIF4) regulates both light and temperature signaling pathways. Here, we identified ENHANCED PHOTOMORPHOGENIC2 (EPP2) as a new repressor of photomorphogenesis in red, far-red, and blue light. Map-based cloning revealed that EPP2 encodes the SEUSS (SEU) transcription regulator. The C-terminus of SEU has transcriptional activation activity and SEU physically interacts with PIF4. Moreover, SEU promotes the expression of many genes, including auxin biosynthetic and responsive genes, and regulates IAA levels in plants. SEU associates with regulatory regions in INDOLE-3-ACETIC ACID INDUCIBLE6 (IAA6) and IAA19 in a PIF4-independent manner, whereas the binding of PIF4 to these genes requires SEU. Furthermore, mutations in SEU affect H3K4me3 methylation at IAA6 and IAA19, and SEU positively regulates warm temperature-mediated hypocotyl growth together with PIF4. Therefore, our results reveal that SEU acts as a central regulator to integrate light and temperature signals to control plant growth by coordinating with PIF4. Copyright © 2018 The Author. Published by Elsevier Inc. All rights reserved.
Mercury's Sodium Exosphere: Observations during the MESSENGER Orbital Phase
NASA Technical Reports Server (NTRS)
Killen, Rosemary M.; Cassidy, Timothy A.; Vervack, Ronald J., Jr.; Burger, Matthew H.; Merkel, Aimee W.; Sarantos, Menelaos; Sprague, Ann L.; McClintock, William E.; Benna, Mehdi; Solomon, Sean C.
2012-01-01
The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft entered into orbit about Mercury on March 18,2011. We now have approximately five Mercury years of data from orbit. Prior to the MESSENGER mission, Mercury's surface-bounded exosphere was known to contain H, He, Na. K, and Ca. The Ultraviolet and Visible Spectrometer (UVVS) began routine orbital observations of both the dayside and nightside exosphere on March 29. 2011, measuring altitude profiles for all previously detected neutral species except for He and K. We focus here on what we have learned about the sodium exosphere: its spatial, seasonal, and sporadic variation. Observations to date permit delineation of the relative roles of photon-stimulated desorption (PSD) and impact vaporization (IV) from seasonal and spatial effects, as well as of the roles of ions both as sputtering agents and in their possible role to enhance the efficiency of PSD. Correlations of Mercury's neutral sodium exosphere with measurements from MESSENGER's Magnetometer (MAG) and Energetic Particle and Plasma Spectrometer (EPPS) provide insight into the roles of ions and electrons. Models incorporating MAG observations provide a basis for identifying the location and area of the surface exposed to solar wind plasma, and EPPS observations reveal episodic populations of energetic electrons in the magnetosphere and the presence of planetary He(+), 0(+), and Na(+),
Cary, Gregory A.; Yoon, Sung Hwan; Torres, Cecilia Garmendia; Wang, Kathie; Hays, Michelle; Ludlow, Catherine; Goodlett, David R.; Dudley, Aimée M.
2014-01-01
Puromycin is an aminonucleoside antibiotic with structural similarity to aminoacyl tRNA. This structure allows the drug to bind the ribosomal A-site and incorporate into nascent polypeptides causing chain termination, ribosomal subunit dissociation, and widespread translational arrest at high concentrations. In contrast, at sufficiently low concentrations, puromycin incorporates primarily at the C-terminus of proteins. While a number of techniques utilize puromycin incorporation as a tool for probing translational activity in vivo, these methods cannot be applied in yeasts that are insensitive to puromycin. Here, we describe a mutant strain of the yeast Saccharomyces cerevisiae that is sensitive to puromycin and characterize the cellular response to the drug. Puromycin inhibits the growth of yeast cells mutant for erg6Δ, pdr1Δ, and pdr3Δ (EPP) on both solid and liquid media. Puromycin also induces the aggregation of the cytoplasmic processing body component Edc3 in the mutant strain. We establish that puromycin is rapidly incorporated into yeast proteins and test the effects of puromycin on translation in vivo. This work establishes the EPP strain as a valuable tool for implementing puromycin-based assays in yeast, which will enable new avenues of inquiry into protein production and maturation. PMID:24610064
Report on FY15 Two-Bar Thermal Ratcheting Test Results
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Yanli; Jetter, Robert I; Baird, Seth T
2015-06-22
Alloy 617 is a reference structural material for very high temperature components of advanced-gas cooled reactors with outlet temperatures in the range of . In order for designers to be able to use Alloy 617 for these high temperature components, Alloy 617 has to be approved for use in Section III (the nuclear section) of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code. A plan has been developed to submit a draft code for Alloy 617 to ASME Section III by 2015. However, the current rules in Subsection NH* for the evaluation of strain limits andmore » creep-fatigue damage using simplified methods based on elastic analysis have been deemed inappropriate for Alloy 617 at temperatures above . The rationale for this exclusion is that at higher temperatures it is not feasible to decouple plasticity and creep deformation, which is the basis for the current simplified rules. This temperature, , is well below the temperature range of interest for this material in High Temperature Gas Cooled Reactor (HTGR) applications. The only current alternative is, thus, a full inelastic analysis which requires sophisticated material models which have been formulated but not yet verified. To address this issue, proposed code rules have been developed which are based on the use of elastic-perfectly plastic (EPP) analysis methods and which are expected to be applicable to very high temperatures. These newly proposed rules also address a long-term objective to provide an option for more simple, comprehensive and easily applied rules than the current so called simplified rules These two-bar tests discussed herein are part of an ongoing series of tests with cyclic loading at high temperatures using specimens representing key features of potential component designs. The initial focus of the two-bar ratcheting test program, to verify the procedure for evaluation of strain limits for Alloy 617 at very high temperatures, has been expanded to respond to guidance from ASME Code committees that the proposed EPP methodology should also apply to other Subsection NH materials throughout their allowed temperature range. To support these objectives, two suites of tests have been accomplished during this reporting period. One suite addresses the issue of the response of Alloy 617 at a lower temperature with tests in range of 500 800oC and a few at 350 650°C. The other suite addresses the response of SS316H up to its current maximum allowed temperature of 1500°F (815°C) In the two-bar test methodology, the two bars can be viewed as specimens taken out of a tubular component across the wall thickness representing the inner wall element and the outer wall element respectively. The two bars are alternately heated and cooled under sustained axial loading to generate ratcheting. A sustained hold time is introduced at the hot extreme of the cycle to capture the accelerated ratcheting and strain accumulation due to creep. Since the boundary conditions are a combination of strain control and load control it is necessary to use two coupled servo-controlled testing machines to achieve the key features of the two-bar representation of actual component behavior. Two-bar thermal ratcheting test results with combinations of applied mean stresses, transient temperature difference and heating and cooling rates were recorded. Tests performed at heating and cooling rates of 30°C/min are comparable to a strain rate of 10 ⁻⁵/sec. At high mean stresses in tension the direction of ratcheting was in-phase with the load, e.g. tensile strain ratcheting under high tensile loading; however, at lower loads, strain ratcheting in compression was observed under net tensile mean stresses. The strain accumulation was proportional to the applied thermal load. However, there was a narrow range of applied load in which the high applied thermal loading did not result in significant strain accumulation. Unfortunately, when the proposed EPP strain limit evaluation rules were applied to the loading history for the two-bar configuration, the predicted narrow range of low strain accumulation did not coincide with the experimental data. However, by the use of inelastic analysis in conjunction with an analytic experiment it was possible to show that the EPP strain limit code case rules could be applied to high temperature structures where the stress and temperature is not uniform throughout which is the general case. Interestingly, the suite of tests on Alloy 617 at the lower temperature range of 500°C to 800oC showed good agreement with the proposed EPP strain limit rules with a much wider band of applied load that exhibited minimal ratcheting. The four tests conducted at the lower temperature range of 350°C to 650°C showed no ratcheting. The suite of tests on SS316H at a temperature range of 515°C to 815°C resembled the results from the tests on Alloy 617 at 650°C to 950°C. Both exhibited a narrow band of applied load wher...« less
The Action of Botulinum Toxin at the Neuromuscular Junction
1980-12-22
fast - twitch " (gastrocnemius) and " slow - twitch " (soleus) muscles ... muscle fibers -"_re not significantly affected by the toxin. It is interesting to note that, although fast - twitch and slow - twitch mucles were...Duchen LW: An electron microscopic study of the changes induced by borulinum o::in in the motor end-plates of slow and fast skeletal muscle fibres of
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bahk, Y.W.; Kim, O.H.; Chung, S.K.
1987-04-01
The informational gains obtained by the use of pinhole collimator scintigraphy (PCS) have been well documented. The present study has been undertaken to prospectively investigate its efficacy in diagnosing several commonly occurring spinal diseases. Patient material consisted of metastatic cancer (39 vertebrae), compression fractures (33 vertebrae), tuberculous spondylitis (17 vertebrae), and pyogenic spondylitis (six vertebrae). PCS findings were characterized in terms of localization, appearance, and homogeneity of abnormal radionuclide accumulation. Thus, metastatic cancer manifested as diffusely or focally homogeneous accumulation within the vertebral body or as a typical short-segmental accumulation along the end-plate, whereas compression fracture manifested as characteristic board-likemore » accumulation along the entire length of end-plates. Tuberculous spondylitis, on the other hand, revealed homogeneous accumulation throughout the vertebral body, and pyogenic spondylitis revealed accumulation at the end-zone of opposing vertebral bodies giving sandwich-like appearance. The disk space at the affected level was not narrowed in the former two diseases but it was narrowed in the latter two. It was concluded that PCS may be useful in differentiating metastatic cancer, compression fracture, tuberculous spondylitis, and pyogenic spondylitis.« less
Height increase, neuromuscular function, and back pain during 6 degrees head-down tilt with traction
NASA Technical Reports Server (NTRS)
Styf, J. R.; Ballard, R. E.; Fechner, K.; Watenpaugh, D. E.; Kahan, N. J.; Hargens, A. R.
1997-01-01
BACKGROUND: Spinal lengthening and back pain are commonly experienced by astronauts exposed to microgravity. METHODS: To develop a ground-based simulation for spinal adaptation to microgravity, we investigated height increase, neuromuscular function and back pain in 6 subjects all of whom underwent two forms of bed rest for 3 d. One form consisted of 6 degrees of head-down tilt (HDT) with balanced traction, while the other was horizontal bed rest (HBR). Subjects had a 2-week recovery period in between the studies. RESULTS: Total body and spinal length increased significantly more and the subjects had significantly more back pain during HDT with balanced traction compared to HBR. The distance between the lower endplate of L4 and upper endplate of S1, as measured by ultrasonography, increased significantly in both treatments to the same degree. Intramuscular pressures in the erector spinae muscles and ankle torque measurements during plantarflexion and dorsiflexion did not change significantly during either treatment. CONCLUSION: Compared to HBR, HDT with balanced traction may be a better method to simulate changes of total body and spinal lengths, as well as back pain seen in microgravity.
Disseminated protothecosis associated with diskospondylitis in a dog.
Manino, Paul M; Oliveira, Fabiano; Ficken, Martin; Swinford, Amy; Burney, Derek
2014-01-01
A 6 yr old female Labrador retriever was evaluated for an acute onset of difficulty walking and a head tilt. Initial physical examination revealed bilateral retinal detachment, a left-sided head tilt, positional rotary nystagmus, and lumbar hyperpathia. Pertinent preliminary diagnostic findings included systemic hypertension, bony lysis and adjacent sclerosis of the vertebral endplates of the first and second lumbar vertebrae, and positive urine and blood cultures for a yeast identified as Candida spp. Concerned about disseminated candidiasis after subsequent subretinal aspirates confirmed the presence of a yeast-like organism, therapy with voriconazole was initiated. Because of progressive clinical deterioration and the poor prognosis for recovery, the dog was eventually euthanized. Postmortem histological examination of tissues, including the affected vertebral endplates, revealed numerous intralesional algae compatible with Prototheca spp. To the authors' knowledge, this report is the first to document a case of protothecal diskospondylitis with possible concurrent candidiasis in a dog. Although typically associated with signs referable to the gastrointestinal tract, this report underscores the importance of not excluding protothecosis as a differential diagnosis when such signs are absent. Lastly, the use of voriconazole appears ineffective for reversing the clinical course of late-stage disseminated protothecosis.
Early effects of carbachol on the morphology of motor endplates of mammalian skeletal muscle fibers.
Voigt, Tilman
2010-03-01
Long-term disturbance of the calcium homeostasis of motor endplates (MEPs) causes necrosis of muscle fibers. The onset of morphological changes in response to this disturbance, particularly in relation to the fiber type, is presently unknown. Omohyoid muscles of mice were incubated for 1-30 minutes in 0.1 mM carbachol, an acetylcholine agonist that causes an inward calcium current. In these muscles, the structural changes of the sarcomeres and the MEP sarcoplasm were evaluated at the light- and electron-microscopic level. Predominantly in type I fibers, carbachol incubation resulted in strong contractures of the sarcomeres underlying the MEPs. Owing to these contractures, the usual beret-like form of the MEP-associated sarcoplasm was deformed into a mushroom-like body. Consequently, the squeezed MEPs partially overlapped the adjacent muscle fiber segments. There are no signs of contractures below the MEPs if muscles were incubated in carbachol in calcium-free Tyrode's solution. Carbachol induced inward calcium current and produced fiber-type-specific contractures. This finding points to differences in the handling of calcium in MEPs. Possible mechanisms for these fiber-type-specific differences caused by carbachol-induced calcium entry are assessed.
Effect of flow rate and concentration difference on reverse electrodialysis system
NASA Astrophysics Data System (ADS)
Kwon, Kilsugn; Han, Jaesuk; Kim, Daejoong
2013-11-01
Various energy conversion technologies have been developed to reduce dependency on limited fossil fuels, including wind power, solar power, hydropower, ocean power, and geothermal power. Among them, reverse electrodialysis (RED), which is one type of salinity gradient power (SGP), has received much attention due to high reliability and simplicity without moving parts. Here, we experimentally evaluated the RED performance with several parameters like flow rate of concentrated and dilute solution, concentration difference, and temperature. RED was composed of endplates, electrodes, spacers, anion exchange membrane, and cation exchange membrane. Endplates are made by a polypropylene. It included the electrodes, flow field for the electrode rinse solution, and path to supply a concentrated and dilute solution. Titanium coated by iridium and ruthenium was used as the electrode. The electrode rinse solution based on hexacyanoferrate system is used to reduce the power loss generated by conversion process form ionic current to electric current. Maximum power monotonously increases as increasing flow rate and concentration difference. Net power has optimal point because pumping power consumption increases with flow rate. This work was supported by Basic Science Research Program (Grat No. NRF-2011-0009993) through the National Research Foundation of Korea.
Ji, Ming-Liang; Qian, Bang-ping; Qiu, Yong; Wang, Bin; Zhu, Ze-zhang; Yu, Yang; Jiang, Jun
2013-10-15
A computed tomographic study. To investigate the change in aortic length in patients with ankylosing spondylitis (AS) with thoracolumbar kyphosis after closing-opening wedge osteotomy (COWO). Several previous studies reported that COWO can effectively correct severe thoracolumbar kyphosis caused by AS. However, one disadvantage of COWO is elongation of the aorta, which increases the risk of aortic injury. To date, no studies have analyzed the alteration in aortic length in patients with AS undergoing COWO for thoracolumbar kyphosis. A total of 21 consecutive patients with AS with a mean age of 38.9 years undergoing COWO for the correction of thoracolumbar kyphosis were retrospectively studied. Radiographical measurements included global kyphosis, thoracic kyphosis, lumbar lordosis, angle of fusion levels, local kyphosis, and anterior height of the osteotomized vertebra. The computed tomographic scans of the spine were used to measure the aortic diameter (at the site of the osteotomy) and length (the length between the superior endplate of the upper instrumented vertebra and the inferior endplate of L4). The aortic length increased by an average of 2.2 cm postoperatively. Significant changes in global kyphosis, local kyphosis, angle of fusion levels, lumbar lordosis, anterior height of the osteotomized vertebra, and aortic diameter at the site of the osteotomy were observed (P < 0.01). Significant correlation was noted between aortic length and changes in global kyphosis (r = 0.525, P = 0.015), local kyphosis (r = 0.654, P = 0.001), angle of fusion levels (r = 0.634, P = 0.002), and lumbar lordosis (r = 0.538, P = 0.012). Aortic lengthening after COWO for correction of kyphosis was quantitatively confirmed by this study. Spine surgeons should be aware of the potential risk for the development of aortic injury in patients with AS undergoing COWO for the correction of thoracolumbar kyphosis. 4.
Imaging of degenerative lumbar intervertebral discs; linking anatomy, pathology and imaging.
Adams, Ashok; Roche, Oran; Mazumder, Asif; Davagnanam, Indran; Mankad, Kshitij
2014-09-01
Low back pain is a common medical condition that has significant implications for healthcare providers and the UK economy. Low back pain can be classified as 'specific' in which an underlying pathophysiological mechanism is identified (eg, herniated intervertebral disc). Advanced imaging should be performed in this situation and in those patients in whom systemic disease is strongly suspected. In the majority (approximately 90%), low back pain in 'non specific' and there is a weak correlation with imaging abnormalities. This is an area of ongoing research and remains controversial in terms of imaging approach and treatment (eg, theory of discogenic pain, interpretation and treatment of endplate changes). With regards Modic endplate changes, current research suggests that an infective component may be involved that may identify novel potential treatments in patients with chronic low back pain refractory to other treatment modalities. MRI is the imaging modality of choice for the assessment of degenerative changes in intervertebral discs. MRI has superior soft tissue contrast resolution when compared to other imaging modalities (eg, plain radiography, CT). An understanding of normal anatomy and MR appearances of intervertebral discs, particularly with regards to how these appearances change with advancing age, is required to aid image interpretation. Knowledge of the spectrum of degenerative processes that may occur in the intervertebral discs is required in order to identify and explain abnormal MRI appearances. As the communication of MRI findings may guide therapeutic decision making and surgical intervention, the terminology used by radiologists must be accurate and consistent. Therefore, description of degenerative disc changes in the current paper is based on the most up-to-date recommendations, the aim being to aid reporting by radiologists and interpretation of reports by referring clinicians. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Functionally Graded Shape Memory Alloy Composites Optimized for Passive Vibration Control
2006-11-20
Nitinol , it is anticipated that the wire can only experience an incomplete hysteresis. 2.1. SMA wires in sleeves continuously bonded to the plate...Gilheany, J. 1995. Control of the natural frequencies of nitinol -reinforced composite beams, Journal of Sound and Vibrations, Vol. 185, 171-185. 3 Ro...J., and Baz, A., 1995. Nitinol -reinforced plates: Part III, Dynamic characteristics, Composites Engineering, Vol. 5, 91-106. 4 Epps, J and Chandra
Non-auditory, electrophysiological potentials preceding dolphin biosonar click production.
Finneran, James J; Mulsow, Jason; Jones, Ryan; Houser, Dorian S; Accomando, Alyssa W; Ridgway, Sam H
2018-03-01
The auditory brainstem response to a dolphin's own emitted biosonar click can be measured by averaging epochs of the instantaneous electroencephalogram (EEG) that are time-locked to the emitted click. In this study, averaged EEGs were measured using surface electrodes placed on the head in six different configurations while dolphins performed an echolocation task. Simultaneously, biosonar click emissions were measured using contact hydrophones on the melon and a hydrophone in the farfield. The averaged EEGs revealed an electrophysiological potential (the pre-auditory wave, PAW) that preceded the production of each biosonar click. The largest PAW amplitudes occurred with the non-inverting electrode just right of the midline-the apparent side of biosonar click generation-and posterior of the blowhole. Although the source of the PAW is unknown, the temporal and spatial properties rule out an auditory source. The PAW may be a neural or myogenic potential associated with click production; however, it is not known if muscles within the dolphin nasal system can be actuated at the high rates reported for dolphin click production, or if sufficiently coordinated and fast motor endplates of nasal muscles exist to produce a PAW detectable with surface electrodes.
Cluster of wound botulism in California: clinical, electrophysiologic, and pathologic study.
Maselli, R A; Ellis, W; Mandler, R N; Sheikh, F; Senton, G; Knox, S; Salari-Namin, H; Agius, M; Wollmann, R L; Richman, D P
1997-10-01
Over a period of 15 months we have seen 6 patients with long-standing history of subcutaneous heroin injections who experienced acute blurred vision, dysphagia, dysarthria, and generalized weakness. Decreased or absent deep tendon reflexes, pupillary abnormalities, incremental responses to fast repetitive nerve stimulation, and positive serology for Clostridia botulinum toxin A were found, but not in all cases. Muscle biopsies showed variable signs of neurogenic atrophy. In vitro electrophysiology studies revealed decreased end-plate potentials quantal content, confirming the presynaptic nature of the disorder. Mechanical ventilation was required in 5 patients. Half of the patients were treated with polyvalent antitoxiin. Prognosis was favorable, though recovery was slow. In conclusion, acute bulbar weakness with visual symptoms in patients with subcutaneous heroin abuse strongly suggets the possibility of wound botulism. High diagnostic suspicion combined with histology and in vitro electrophysiology confirmation of presynaptic failure, especially in seronegative cases, may significantly improve morbidity.
Phan, Kevin; Maharaj, Monish; Assem, Yusuf; Mobbs, Ralph J
2016-09-01
Lumbar interbody fusion represents an effective surgical intervention for patients with lumbar degenerative diseases, spondylolisthesis, disc herniation, pseudoarthrosis and spinal deformities. Traditionally, conventional open anterior lumbar interbody fusion and posterior/transforaminal lumbar interbody fusion techniques have been employed with excellent results, but each with their own advantages and caveats. Most recently, the antero-oblique trajectory has been introduced, providing yet another corridor to access the lumbar spine. Termed the oblique lumbar interbody fusion, this approach accesses the spine between the anterior vessels and psoas muscles, avoiding both sets of structures to allow efficient clearance of the disc space and application of a large interbody device to afford distraction for foraminal decompression and endplate preparation for rapid and thorough fusion. This review aims to summarize the early clinical results and complications of this new technique and discusses potential future directions of research. Copyright © 2016 Elsevier Ltd. All rights reserved.
Modelled thermal and dynamical responses of the middle atmosphere to EPP-induced ozone changes
NASA Astrophysics Data System (ADS)
Karami, K.; Braesicke, P.; Kunze, M.; Langematz, U.; Sinnhuber, M.; Versick, S.
2015-11-01
Energetic particles including protons, electrons and heavier ions, enter the Earth's atmosphere over the polar regions of both hemispheres, where they can greatly disturb the chemical composition of the upper and middle atmosphere and contribute to ozone depletion in the stratosphere and mesosphere. The chemistry-climate general circulation model EMAC is used to investigate the impact of changed ozone concentration due to Energetic Particle Precipitation (EPP) on temperature and wind fields. The results of our simulations show that ozone perturbation is a starting point for a chain of processes resulting in temperature and circulation changes over a wide range of latitudes and altitudes. In both hemispheres, as winter progresses the temperature and wind anomalies move downward with time from the mesosphere/upper stratosphere to the lower stratosphere. In the Northern Hemisphere (NH), once anomalies of temperature and zonal wind reach the lower stratosphere, another signal develops in mesospheric heights and moves downward. Analyses of Eliassen and Palm (EP) flux divergence show that accelerating or decelerating of the stratospheric zonal flow is in harmony with positive and negative anomalies of the EP flux divergences, respectively. This results suggest that the oscillatory mode in the downwelling signal of temperature and zonal wind in our simulations are the consequence of interaction between the resolved waves in the model and the mean stratospheric flow. Therefore, any changes in the EP flux divergence lead to anomalies in the zonal mean zonal wind which in turn feed back on the propagation of Rossby waves from the troposphere to higher altitudes. The analyses of Rossby waves refractive index show that the EPP-induced ozone anomalies are capable of altering the propagation condition of the planetary-scale Rossby waves in both hemispheres. It is also found that while ozone depletion was confined to mesospheric and stratospheric heights, but it is capable to alter Rossby wave propagation down to tropospheric heights. In response to an accelerated polar vortex in the Southern Hemisphere (SH) late wintertime, we found almost two weeks delay in the occurrence of mean dates of Stratospheric Final Warming (SFW). These results suggest that the stratosphere is not merely a passive sink of wave activity from below, but it plays an active role in determining its own budget of wave activity.
Explosive Venting Technology for Cook-Off Response Mitigation
2010-07-01
endplate blew off 188.3 PAX-28 Go 6.4 Explode, HE boiled out, body banana peeled 177.8 PAX-28 No go 7.6 Burn, HE boiled out of fixture, smoking, then burn...PAX-28 5.1-mm diameter vent test was to blow off the top fixture and peel off three out of the four heating bands while leaving the fixture in its
Liphofer, J P; Theodoridis, T; Becker, G T; Koester, O; Schmid, G
2006-11-01
To study the influence of (Modic) signal alterations (SA) of the cartilage endplate (CEP) of vertebrae L3-S1 on the outcome of an in-patient minimally invasive treatment (MIT) using epidural injections on patients with lumbar disc herniation (LDH). The MR images of 59 consecutive patients with LDH within segments L3/L4 - L5/S1 undergoing in-patient minimally invasive treatment with epidural injections were evaluated in a clinical study. The (Modic) signal alterations of the CEP were recorded using T1- and T2-weighted sagittal images. On the basis of the T2-weighted sagittal images, the extension and distribution of the SA were measured by dividing each CEP into 9 areas. The outcome of the MIT was recorded using the Oswestry Disability Index (ODI) before and after therapy and in a 3-month follow-up. Within a subgroup of patients (n = 35), the distribution and extension of the signal alterations were correlated with the development of the ODI. Segments with LDH showed significantly more (p < 0.001) SA of the CEP than segments without LDH. Although the extension of the SA was not dependent on sex, it did increase significantly with age (p = 0.017). The outcome after MIT did not depend on the sex and age of the patients nor on the type of LDH. The SA extension tended to have a negative correlation with the outcome after MIT after 3 months (p = 0.071). A significant negative correlation could be established between the SA extension in the central section of the upper endplate and the outcome after 3 months (p = 0.019). 1. Lumbar disc herniation is clearly associated with the prevalence of (Modic) signal alterations. 2. Extensive signal alterations tend to correlate with a negative outcome of an MIT using epidural injections. 3. Such SA in the central portion of the upper CEP correlate significantly with a negative treatment result. 4. The central portion of the upper CEP being extensively affected by (Modic) SA is a negative predictor for the success of a minimally invasive pain therapy.
Kuisma, Mari; Karppinen, Jaro; Niinimäki, Jaakko; Ojala, Risto; Haapea, Marianne; Heliövaara, Markku; Korpelainen, Raija; Taimela, Simo; Natri, Antero; Tervonen, Osmo
2007-05-01
Cross-sectional comparison of self-reported low back pain (LBP) symptoms and Modic findings on magnetic resonance imaging (MRI). To investigate associations of frequency and intensity of LBP and sciatic pain with Modic changes in a sample of middle-aged male workers with or without whole-body vibration exposure. Vertebral endplate changes are bone marrow lesions visible on MRI and are assumed to be associated with degenerative intervertebral disc disease. Associations of these so-called Modic changes with clinical symptoms are controversial. Furthermore, most of these studies have been performed in selected series of patients. A total of 228 middle-aged male workers (159 train engineers and 69 sedentary controls) from northern Finland underwent sagittal T1 and T2-weighted MRI. Both endplates of 1140 lumbar interspaces were graded for type and extent of Modic changes. Logistic regression was used to analyze associations of pain variables with Modic changes. Train engineers had on the average higher sciatic pain scores than the sedentary controls, but the prevalence of Modic changes was similar in both occupational groups. Altogether, 178 Modic changes in 128 subjects were recorded: 30% were type I, 66% type II, and 4% both types I and II. Eighty percent of changes occurred at L4-L5 or L5-S1. Modic changes at L5-S1 showed significant association with pain symptoms with increased frequency of LBP (odds ratio [OR] 2.28; 95% confidence interval [CI] 1.44-3.15) and sciatica episodes (OR 1.44; 95% CI 1.01-1.89), and with higher LBP visual analog scores during the past week (OR 1.36; 95% CI 1.06-1.70). Type I lesions and extensive lesions in particular were closely associated with pain. Modic changes at L5-S1 and Modic type I lesions are more likely to be associated with pain symptoms than other types of Modic changes or changes located at other lumbar levels.
NASA Astrophysics Data System (ADS)
Smyth, William Henry
2014-02-01
1. Details respecting the parish and manor of Hartwell: locality, geology, produce, and general statistics; 2. The successive lords of the manor of Hartwell, from the Conquest to the present time: Peverel, De Hertewell, Luton, Hampden, and Lee; 3. Particulars respecting Hartwell House: its appartments, paintings, library, museum, numismata, and Egyptian antiquities; 4. Origin of the Hartwell Observatory. The transit-room. The equatorial tower. Mr Epps's meridional observations. The double-stars measured by Captain Smyth. Encke's comet. The meteorological department; Appendix; Index.
Operation JUBILEE: The Allied Raid on Dieppe (1942) -- A Historical Analysis of a Planning Failure
2008-03-06
8217..’ ; I • l345.. THE FORMA ~~N OF ~~T F~RCES ii ~ \\ i J •.~..<a) For any amphIbIous CllDlpalgn lnvolvmg assaults on stroQgly defended coast:i held...the general pulicy of His Majesty’s Governm.ent. although an CXl’I’ptillll might havc been made .. iri the,-.o I .’ .. case of D~eppe,had the
Shake table test of soil-pile groups-bridge structure interaction in liquefiable ground
NASA Astrophysics Data System (ADS)
Tang, Liang; Ling, Xianzhang; Xu, Pengju; Gao, Xia; Wang, Dongsheng
2010-03-01
This paper describes a shake table test study on the seismic response of low-cap pile groups and a bridge structure in liquefiable ground. The soil profile, contained in a large-scale laminar shear box, consisted of a horizontally saturated sand layer overlaid with a silty clay layer, with the simulated low-cap pile groups embedded. The container was excited in three El Centro earthquake events of different levels. Test results indicate that excessive pore pressure (EPP) during slight shaking only slightly accumulated, and the accumulation mainly occurred during strong shaking. The EPP was gradually enhanced as the amplitude and duration of the input acceleration increased. The acceleration response of the sand was remarkably influenced by soil liquefaction. As soil liquefaction occurred, the peak sand displacement gradually lagged behind the input acceleration; meanwhile, the sand displacement exhibited an increasing effect on the bending moment of the pile, and acceleration responses of the pile and the sand layer gradually changed from decreasing to increasing in the vertical direction from the bottom to the top. A jump variation of the bending moment on the pile was observed near the soil interface in all three input earthquake events. It is thought that the shake table tests could provide the groundwork for further seismic performance studies of low-cap pile groups used in bridges located on liquefiable groun.
Fabrizio, Cecilia S; Lam, Tai Hing; Hirschmann, Malia R; Pang, Irene; Yu, Nancy Xiaonan; Wang, Xin; Stewart, Sunita M
2015-08-01
There is a shortage of culturally appropriate, brief, preventive interventions designed to be sustainable and acceptable for community participants in nonwestern cultures. Parents' ability to regulate their emotions is an important factor for psychological well-being of the family. In Chinese societies, emotional regulation may be more important in light of the cultural desirability of maintaining harmonious family relationships. The objectives of our randomized controlled trial were to test the effectiveness of our Effective Parenting Programme (EPP) to increase the use of emotional management strategies (primary outcome) and enhance the parent-child relationship (secondary outcome). We utilized design characteristics that promoted recruitment, retention, and intervention sustainability. We randomized a community sample of 412 Hong Kong middle- and low-income mothers of children aged 6-8 years to the EPP or attention control group. At 3, 6 and 12- month follow up, the Effective Parent Program group reported greater increases in the use of emotion management strategies during parent-child interactions, with small to medium effect size, and lower negative affect and greater positive affect, subjective happiness, satisfaction with the parent-child relationship, and family harmony, compared to the control group, with small to medium effect size. Our results provided evidence of effectiveness for a sustainable, preventive, culturally appropriate, cognitive behaviorally-based emotion management program, in a non-clinical setting for Chinese mothers. HKCTR-1190. Copyright © 2015 Elsevier Ltd. All rights reserved.
Wright, David J.; Brouwer, Lyanne; Mannarelli, Maria-Elena; Burke, Terry; Komdeur, Jan
2016-01-01
The prevalence and significance of precopulatory mate choice remains keenly debated. The major histocompatibility complex (MHC) plays a key role in vertebrate adaptive immunity, and variation at the MHC influences individual survival. Although MHC-dependent mate choice has been documented in certain species, many other studies find no such pattern. This may be, at least in part, because in natural systems constraints may reduce the choices available to individuals and prevent full expression of underlying preferences. We used translocations to previously unoccupied islands to experimentally reduce constraints on female social mate choice in the Seychelles warbler (Acrocephalus sechellensis), a species in which patterns of MHC-dependent extrapair paternity (EPP), but not social mate choice, have been observed. We find no evidence of MHC-dependent social mate choice in the new populations. Instead, we find that older males and males with more microsatellite heterozygosity are more likely to have successfully paired. Our data cannot resolve whether these patterns in pairing were due to male–male competition or female choice. However, our research does suggest that female Seychelles warblers do not choose social mates using MHC class I to increase fitness. It may also indicate that the MHC-dependent EPP observed in the source population is probably due to mechanisms other than female precopulatory mate choice based on MHC cues. PMID:26792973
NASA Astrophysics Data System (ADS)
Carmona, A. M.; Poveda, G.; Sivapalan, M.; Vallejo-Bernal, S. M.; Bustamante, E.
2015-10-01
This paper studies a 3-D generalization of Budyko's framework designed to capture the mutual interdependence among long-term mean actual evapotranspiration (E), potential evapotranspiration (Ep) and precipitation (P). For this purpose we use three dimensionless and dependent quantities: Ψ = E/P, Φ = Ep/P and Ω = E/Ep. This 3-D space and its 2-D projections provide an interesting setting to test the physical soundness of Budyko's hypothesis. We demonstrate analytically that Budyko-type equations are unable to capture the physical limit of the relation between Ω and Φ in humid environments, owing to the unfeasibility of Ep/P → 0 at E/Ep = 1. Using data from 146 sub-catchments in the Amazon River basin we overcome this inconsistency by proposing a physically consistent power law: Ψ = k Φe, with k = 0.66, and e = 0.83 (R2 = 0.93). This power law is compared with two other Budyko-type equations. Taking into account the goodness of fits and the ability to comply with the physical limits of the 3-D space, our results show that the power law is better suited to model the coupled water and energy balances within the Amazon River basin. Moreover, k is found to be related to the partitioning of energy via evapotranspiration in terms of Ω. This suggests that our power law implicitly incorporates the complementary relationship of evapotranspiration into the Budyko curve, which is a consequence of the dependent nature of the studied variables within our 3-D space. This scaling approach is also consistent with the asymmetrical nature of the complementary relationship of evapotranspiration. Looking for a physical explanation for the parameters k and e, the inter-annual variability of individual catchments is studied. Evidence of space-time symmetry in Amazonia emerges, since both between-catchment and between-year variability follow the same Budyko curves. Finally, signs of co-evolution of catchments are explored by linking spatial patterns of the power law parameters with fundamental characteristics of the Amazon River basin. In general, k and e are found to be related to vegetation, topography and water in soils.
Homma, S; Nakajima, Y; Hayashi, K; Toma, S
1986-01-01
Conduction of an action potential along skeletal muscle fibers was graphically displayed by unidimensional latency-topography, UDLT. Since the slopes of the equipotential line were linear and the width of the line was constant, it was possible to calculate conduction velocity from the slope. To determine conduction direction of the muscle action potential elicited by electric stimulation applied directly to the muscle, surface recording electrodes were placed on a two-dimensional plane over a human muscle. Thus a bi-dimensional topography was obtained. Then, twelve or sixteen surface electrodes were placed linearly along the longitudinal direction of the action potential conduction which was disclosed by the bi-dimensional topography. Thus conduction velocity of muscle action potential in man, calculated from the slope, was for m. brachioradialis, 3.9 +/- 0.4 m/s; for m. biceps brachii, 3.6 +/- 0.2 m/s; for m. sternocleidomastoideus, 3.6 +/- 0.4 m/s. By using a tungsten microelectrode to stimulate the motor axons, a convex-like equipotential line of an action potential in UDLT was obtained from human muscle fibers. Since a similar pattern of UDLT was obtained from experiments on isolated frog muscles, in which the muscle action potential was elicited by stimulating the motor axon, it was assumed that the maximum of the curve corresponds to the end-plate region, and that the slopes on both sides indicate bi-directional conduction of the action potential.
Technology advancement of the electrochemical CO2 concentrating process
NASA Technical Reports Server (NTRS)
Schubert, F. H.; Woods, R. R.; Hallick, T. M.; Heppner, D. B.
1977-01-01
A five-cell, liquid-cooled advanced electrochemical depolarized carbon dioxide concentrator module was fabricated. The cells utilized the advanced, lightweight, plated anode current collector concept and internal liquid-cooling. The five cell module was designed to meet the carbon dioxide removal requirements of one man and was assembled using plexiglass endplates. This one-man module was tested as part of an integrated oxygen generation and recovery subsystem.
Reinnervation of Paralyzed Muscle by Nerve Muscle Endplate Band Grafting
2016-10-01
PREPARED FOR: U.S. Army Medical Research and Materiel Command Fort Detrick, Maryland 21702-5012 DISTRIBUTION STATEMENT: Approved for Public Release... Medical Research and Materiel Command Fort Detrick, Maryland 21702-5012 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION / AVAILABILITY STATEMENT...Nyirenda, PhD1 Liancai Mu, MD, PhD1 1Department of Research , Hackensack University Medical Center, Upper Airway Research Laboratory, Hackensack, New
Vaezi, P.; Holland, C.; Thakur, S. C.; ...
2017-04-01
The Controlled Shear Decorrelation Experiment (CSDX) linear plasma device provides a unique platform for investigating the underlying physics of self-regulating drift-wave turbulence/zonal flow dynamics. A minimal model of 3D drift-reduced nonlocal cold ion fluid equations which evolves density, vorticity, and electron temperature fluctuations, with proper sheath boundary conditions, is used to simulate dynamics of the turbulence in CSDX and its response to changes in parallel boundary conditions. These simulations are then carried out using the BOUndary Turbulence (BOUT++) framework and use equilibrium electron density and temperature profiles taken from experimental measurements. The results show that density gradient-driven drift-waves are themore » dominant instability in CSDX. However, the choice of insulating or conducting endplate boundary conditions affects the linear growth rates and energy balance of the system due to the absence or addition of Kelvin-Helmholtz modes generated by the sheath-driven equilibrium E × B shear and sheath-driven temperature gradient instability. Moreover, nonlinear simulation results show that the boundary conditions impact the turbulence structure and zonal flow formation, resulting in less broadband (more quasi-coherent) turbulence and weaker zonal flow in conducting boundary condition case. These results are qualitatively consistent with earlier experimental observations.« less
Lazennec, Jean-Yves; Aaron, Alain; Brusson, Adrien; Rakover, Jean-Patrick; Rousseau, Marc-Antoine
2013-02-01
The viscoelastic lumbar disk prosthesis-elastic spine pad (LP-ESP(®)) is an innovative one-piece deformable but cohesive interbody spacer providing 6 full degrees of freedom about the 3 axes, including shock absorption. A 20-year research program has demonstrated that this concept provides mechanical properties very close to those of a natural disk. Improvements in technology have made it possible to solve the problem of the bond between the elastic component and the titanium endplates and to obtain an excellent biostability. The prosthesis geometry allows limited rotation and translation with resistance to motion (elastic return property) aimed at avoiding overload of the posterior facets. The rotation center can vary freely during motion. It thus differs substantially from current prostheses, which are 2- or 3-piece devices involving 1 or 2 bearing surfaces and providing 3 or 5 degrees of freedom. This design and the adhesion-molding technology differentiate the LP-ESP prosthesis from other mono-elastomeric prostheses, for which the constraints of shearing during rotations or movement are absorbed at the endplate interface. Seven years after the first implantation, we can document in a solid and detailed fashion the course of clinical outcomes and the radiological postural and kinematic behavior of this prosthesis.
2014-03-27
Operations on Alternate Launch and Recovery Surfaces (No. ESL -TR-83-46). Tyndall Air Force Base, FL: Air Force Engineering and Services Center. U.S...Little, D. N., Thompson, M. R., Terrell, R. L., Epps, J. A., & Barenberg, E. J. (1987). Soil Stabilization for Roadways and Airfields (No. ESL -TR...Alternate Launch and Recovery Surfaces (No. ESL -TR-83-46). Tyndall Air Force Base, FL: Air Force Engineering and Services Center. U.S. Army Corps of
Structural Characterization of Atomically Thin Hexagonal Boron Nitride via Raman Spectroscopy
2014-03-27
thickness and the use of depth profiling to maximize spectral returns. Chapter 3 also outlines the experimental set-up and procedures related to...section. 46 Figure 4.8: Unaltered spectral return of both Site 1 (A) and Site 2 ( B ). As to be expected the relative intensity of the Raman...Dent, Modern Raman Spectroscopy : A Practical Approach. Wiley, 2006, p. 224. 59 25. A. B . Kaul, E. W . Wong, L. Epp, and B . D. Hunt, “Two
Inhibition of Xenobiotic-Degrading Hydrolases by Organophosphinates
1986-07-01
TMB-4 doubled the rates of recovery. Concentrations of Lcarboxyl- CIprocaine in blood of mice were increased three-fold for 27 m I" exposure to 0-4...enzyme was found to have recovered 45.7% of its activity 24 h 35 after exposure to 4.87 x 10- 4 M EPP (Table 10). Neither rabbit liver carboxylesterase...case of a competitive mechanism of inhibition. It is possible that IPP and DPP were competitive inhibitors acting by occupation of the active site of
VizieR Online Data Catalog: Improved astrometry bor BE74 stars (Howarth, 2012)
NASA Astrophysics Data System (ADS)
Howarth, I. D.
2012-10-01
Accurate astrometry is required to reliably cross-match 20th-century catalogues against 21st-century surveys. The present work aims to provide such astrometry for the 625 entries of the Bohannan & Epps (BE74; 1974A&AS...18...47B) catalogue of Hα emission-line stars. BE74 targets have been individually identified in digital images and, in most cases, unambiguously matched to entries in the UCAC4 (I/322) astrometric catalogue. (3 data files).
NEW SERDP Project: Copper- Beryllium Alternatives Alloys Development
2011-02-10
ChemistryRefining Lath Martensite: Ms≥200°C Nickel: Cleavage Resistance Cobalt: SRO Recovery Resistance Chromium : Corrosion Resistance σuts > 280 ksi σys...230 ksi (Cr, Mo, V, Fe)2 C Avoid Fe3C, M6C, M7C3, M23C6 ~ 15-5 PH Chromium Partitioning Into Oxide Film epp and icrit Chromium , Molybdenum, Vandium...Primary exposure risk is Be dust or fume inhalation – ~ 4-10% of population show sensitivity to Be – Allergic type reaction in lungs creating fluid
NS(B) (Nitrogen Sulfide (B State)) Spectrum Theory and Code
1989-05-01
8217TRAhS’oTRWCNp laP) ,NIfIP C NOTE: EP- BPP <C FCF RED DEGRADED BANDS C PP- BPP >C FCF BLUE DEGRACED eANCS WRITEC3o*) *BP-EPPs’f9(NN*1,I)-8CNNpIP) 60... FMA X. GT .Ft!ACLC .AND .C FPA X1 /FMAX ) GT..2) THEN XPEAK (N,IoIP)=XI1 YP EAK (N.,!,IP) rnPA)I( PE AX(N, IIP) ,FPAX) FfAX CLD=F PAX ENDIF 5
A Fast Event Preprocessor and Sequencer for the Simbol-X Low Energy Detector
NASA Astrophysics Data System (ADS)
Schanz, T.; Tenzer, C.; Maier, D.; Kendziorra, E.; Santangelo, A.
2009-05-01
The Simbol-X Low Energy Detector (LED), a 128×128 pixel DEPFET (Depleted Field Effect Transistor) array, will be read out at a very high rate (8000 frames/second) and, therefore, requires a very fast on board electronics. We present an FPGA-based LED camera electronics consisting of an Event Preprocessor (EPP) for on board data preprocessing and filtering of the Simbol-X low-energy detector and a related Sequencer (SEQ) to generate the necessary signals to control the readout.
The Development of French Nuclear Forces
1987-11-01
4.1 a rc I -MM RON -- .’-.U . . tn L) L- _*z T M - N EppCV :c 4:-ea THE DEVELOPMENT OF FRENCH NUCLEAR FORCES SMEEC TEV46 P 1 9 1988 Martin J. Wisda...TABLES 1. Transformation of the French Nuclear Force ..... . 100 2. Characteristics of French Nucleac Weapons . . .. 01 3. French Defense Expenditures...pap-er is to examine how and why the French undertook the development of their own nuclear force and through this examination, argue that the French
Jiménez-Martínez, Miriam C; Montalvo-González, Efigenia; Sáyago-Ayerdi, Sonia G; Mercado-Mercado, Gilberto; Ramírez-de León, José A; Paz-Gamboa, Ernestina; Vivar-Vera, Maria A
2017-06-01
The impact of high-pressure processing (HPP) on the polyphenol (PP) content and antioxidant activity (AOX) of plantain pulp was evaluated. Pressures of 400, 500 and 600 MPa were applied to plantain pulp for 90 and 180 s at room temperature (25 °C). Polyphenoloxidase activity, extractable (EPP) and non-extractable PP (NEPP) contents, flavonoid content and AOX (FRAP, ABTS •+ ) were evaluated. In addition, PP identification was performed using high-performance liquid chromatography. Polyphenoloxidase activity was inhibited after HPP under all of the conditions studied. Increases of 110.80% and 137.40% in EPP content under conditions of 500 MPa/180 s and 600 MPa/90 s were observed with a simultaneous improvement in the AOX with increments of up to 128.71%. The treatment under conditions of 500 MPa/90 s had the highest total PP content, including the highest content of flavonoids (0.22 g ellagic acid equivalents kg -1 dry weight) and the proportion of NEPP that contained hydrolysable PPs (91.12 g gallic acid equivalents kg -1 dry weight with high AOX. The identified PPs included catechin, quercetin, gallic and hydroxybenzoic acids. HPP performed at a room temperature can be used for improving the total content of PP compounds in plantain pulp under specific pressure and time conditions. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.
Current issues in malignant pleural mesothelioma evaluation and management.
Ai, Jing; Stevenson, James P
2014-09-01
Malignant pleural mesothelioma (MPM) is an uncommon disease most often associated with occupational asbestos exposure and is steadily increasing in worldwide incidence. Patients typically present at an older age, with advanced clinical stage and other medical comorbidities, making management quite challenging. Despite great efforts, the prognosis of MPM remains poor, especially at progression after initial treatment. Macroscopic complete resection of MPM can be achieved through extrapleural pneumonectomy (EPP) or extended (ie, radical) pleurectomy (e-P/D) in selected patients and can result in prolonged survival when incorporated into a multimodality approach. Given the morbidity associated with surgical resection of MPM, optimizing identification of appropriate patients is essential. Unfortunately, most patients are not candidates for EPP or e-P/D due to advanced stage, age, and/or medical comorbidity. Pemetrexed and platinum combination chemotherapy has become the cornerstone of therapy for patients with unresectable disease because the combination is associated with improved survival and quality of life in treated patients. However, MPM eventually becomes resistant to initial therapy, and benefit to further lines of therapy has not been substantiated in randomized clinical trials. Translational research has provided exciting insights into tumorigenesis, biomarkers, and immune response in MPM, leading to the development of multiple novel therapeutic agents that are currently in clinical trials. These advances hold the promise of a new era in the treatment of MPM and suggest that this disease will not be left behind in the war on cancer. ©AlphaMed Press.
Deal, Cheri; Hasselmann, Caroline; Pfäffle, Roland W; Zimmermann, Alan G; Quigley, Charmian A; Child, Christopher J; Shavrikova, Elena P; Cutler, Gordon B; Blum, Werner F
2013-01-01
Magnetic resonance imaging (MRI) is used to investigate the etiology of growth hormone deficiency (GHD). This study examined relationships between MRI findings and clinical/hormonal phenotypes in children with GHD in the observational Genetics and Neuroendocrinology of Short Stature International Study, GeNeSIS. Clinical presentation, hormonal status and first-year GH response were compared between patients with pituitary imaging abnormalities (n = 1,071), patients with mutations in genes involved in pituitary development/GH secretion (n = 120) and patients with idiopathic GHD (n = 7,039). Patients with hypothalamic-pituitary abnormalities had more severe phenotypes than patients with idiopathic GHD. Additional hormonal deficiencies were found in 35% of patients with structural abnormalities (thyroid-stimulating hormone > adrenocorticotropic hormone > luteinizing hormone/follicle-stimulating hormone > antidiuretic hormone), most frequently in patients with septo-optic dysplasia (SOD). Patients with the triad [ectopic posterior pituitary (EPP), pituitary aplasia/hypoplasia and stalk defects] had a more severe phenotype and better response to GH treatment than patients with isolated abnormalities. The sex ratio was approximately equal for patients with SOD, but there was a significantly higher proportion of males (approximately 70%) in the EPP, pituitary hypoplasia, stalk defects, and triad categories. This large, international database demonstrates the value of classification of GH-deficient patients by the presence and type of hypothalamic-pituitary imaging abnormalities. This information may assist family counseling and patient management. Copyright © 2013 S. Karger AG, Basel.
Lee, Jaeyoung; Yasmin, Shamsunnahar; Eluru, Naveen; Abdel-Aty, Mohamed; Cai, Qing
2018-02-01
In traffic safety literature, crash frequency variables are analyzed using univariate count models or multivariate count models. In this study, we propose an alternative approach to modeling multiple crash frequency dependent variables. Instead of modeling the frequency of crashes we propose to analyze the proportion of crashes by vehicle type. A flexible mixed multinomial logit fractional split model is employed for analyzing the proportions of crashes by vehicle type at the macro-level. In this model, the proportion allocated to an alternative is probabilistically determined based on the alternative propensity as well as the propensity of all other alternatives. Thus, exogenous variables directly affect all alternatives. The approach is well suited to accommodate for large number of alternatives without a sizable increase in computational burden. The model was estimated using crash data at Traffic Analysis Zone (TAZ) level from Florida. The modeling results clearly illustrate the applicability of the proposed framework for crash proportion analysis. Further, the Excess Predicted Proportion (EPP)-a screening performance measure analogous to Highway Safety Manual (HSM), Excess Predicted Average Crash Frequency is proposed for hot zone identification. Using EPP, a statewide screening exercise by the various vehicle types considered in our analysis was undertaken. The screening results revealed that the spatial pattern of hot zones is substantially different across the various vehicle types considered. Copyright © 2017 Elsevier Ltd. All rights reserved.
Ferrandiz-Rovira, Mariona; Allainé, Dominique; Callait-Cardinal, Marie-Pierre; Cohas, Aurélie
2016-07-01
Sexual selection through female mate choice for genetic characteristics has been suggested to be an important evolutionary force maintaining genetic variation in animal populations. However, the genetic targets of female mate choice are not clearly identified and whether female mate choice is based on neutral genetic characteristics or on particular functional loci remains an open question. Here, we investigated the genetic targets of female mate choice in Alpine marmots (Marmota marmota), a socially monogamous mammal where extra-pair paternity (EPP) occurs. We used 16 microsatellites to describe neutral genetic characteristics and two MHC loci belonging to MHC class I and II as functional genetic characteristics. Our results reveal that (1) neutral and MHC genetic characteristics convey different information in this species, (2) social pairs show a higher MHC class II dissimilarity than expected under random mate choice, and (3) the occurrence of EPP increases when social pairs present a high neutral genetic similarity or dissimilarity but also when they present low MHC class II dissimilarity. Thus, female mate choice is based on both neutral and MHC genetic characteristics, and the genetic characteristics targeted seem to be context dependent (i.e., the genes involved in social mate choice and genetic mate choice differ). We emphasize the need for empirical studies of mate choice in the wild using both neutral and MHC genetic characteristics because whether neutral and functional genetic characteristics convey similar information is not universal.
NASA Astrophysics Data System (ADS)
Granger Morgan, M.
2011-04-01
In a book for the general public published a year before his death, Carl Sagan wrote, "Every time a scientific paper presents a bit of data, it's accompanied by an error bar---a quiet but instant reminder that no knowledge is complete or perfect." For those of us educated in experimental natural science such an observation seems so obvious as to hardly need saying. Yet when, after completing a PhD in experimental radio physics, I began to work on problems in environmental and energy risk and policy analysis in the early 1970s, I was amazed to find that the characterization and treatment of uncertainty was almost completely lacking in the analysis of that day. In the first part of this talk, I will briefly summarize how I, and a number of my physics-educated colleagues, have worked to rectify this situation. Doctoral education in the Department of Engineering and Public Policy (EPP) at Carnegie Mellon University has also been shaped by a number of ideas and problem-solving styles that derive from physics. These have been strengthened considerably through integration with a number of ideas from experimental social science -- a field that too many in physics ignore or even belittle. In the second part of the talk, I will describe the PhD program in EPP, talk a bit about some of its unique features, and describe a few of the problems we address.
Lembke, Kayly M; Scudder, Charles; Morton, David B
2017-09-27
Defects in the RNA-binding protein, TDP-43, are known to cause a variety of neurodegenerative diseases, including amyotrophic lateral sclerosis and frontotemporal lobar dementia. A variety of experimental systems have shown that neurons are sensitive to TDP-43 expression levels, yet the specific functional defects resulting from TDP-43 dysregulation have not been well described. Using the Drosophila TDP-43 ortholog TBPH, we previously showed that TBPH-null animals display locomotion defects as third instar larvae. Furthermore, loss of TBPH caused a reduction in cacophony , a Type II voltage-gated calcium channel, expression and that genetically restoring cacophony in motor neurons in TBPH mutant animals was sufficient to rescue the locomotion defects. In the present study, we examined the relative contributions of neuromuscular junction physiology and the motor program to the locomotion defects and identified subsets of neurons that require cacophony expression to rescue the defects. At the neuromuscular junction, we showed mEPP amplitudes and frequency require TBPH. Cacophony expression in motor neurons rescued mEPP frequency but not mEPP amplitude. We also showed that TBPH mutants displayed reduced motor neuron bursting and coordination during crawling and restoring cacophony selectively in two pairs of cells located in the brain, the AVM001b/2b neurons, also rescued the locomotion and motor defects, but not the defects in neuromuscular junction physiology. These results suggest that the behavioral defects associated with loss of TBPH throughout the nervous system can be associated with defects in a small number of genes in a limited number of central neurons, rather than peripheral defects. SIGNIFICANCE STATEMENT TDP-43 dysfunction is a common feature in neurodegenerative diseases, including amyotrophic lateral sclerosis, frontotemporal lobar dementia, and Alzheimer's disease. Loss- and gain-of-function models have shown that neurons are sensitive to TDP-43 expression levels, but the specific defects caused by TDP-43 loss of function have not been described in detail. A Drosophila loss-of-function model displays pronounced locomotion defects that can be reversed by restoring the expression levels of a voltage-gated calcium channel, cacophony. We show these defects can be rescued by expression of cacophony in motor neurons and by expression in two pairs of neurons in the brain. These data suggest that loss of TDP-43 can disrupt the central circuitry of the CNS, opening up identification of alternative therapeutic targets for TDP-43 proteinopathies. Copyright © 2017 the authors 0270-6474/17/379486-12$15.00/0.
Effect of oxygen at high pressure on spontaneous transmitter release.
Colton, J S; Colton, C A
1978-11-01
The effect of oxygen at high pressure (OHP) on resting membrane properties (effective membrane resistance (Reff) and membrane potential (Vm)) and the spontaneous release of excitatory transmitter were examined at the lobster neuromuscular junction. Pressurization with 100% oxygen to 150 pounds per square inch gauge pressure (psig) or with nitrogen to 150 psig (7,000 mmHg nitrogen and 135 mmHg oxygen) produced a decrease in Reff associated with a hyperpolarization of Vm. These changes, however, returned to control values within 20--30 min after completion of pressurization. Spontaneous release of excitatory transmitter was shown to increase dramatically in the presence of 100% oxygen at 150 psig. The increase in miniature end-plate potential (MEPP) frequency persisted beyond the transient changes seen with Reff and Vm. This effect was selective to oxygen, as pressurization with nitrogen did not produce an increase in MEPP frequency. No change in average MEPP amplitude was seen with either OHP or pressure alone. An OHP-induced increase in MEPP frequency was also seen at the frog neuromuscular junction. The results indicate that both glutamate-mediated and acetylcholine-mediated synaptic transmission are altered by OHP.
Du, Ailian; Huang, Shiqian; Zhao, Xiaonan; Zhang, Yun; Zhu, Lixun; Ding, Ji; Xu, Congfeng
2016-01-15
After binding by acetylcholine released from a motor neuron, a nicotinic acetylcholine receptor at the neuromuscular junction produces a localized end-plate potential, which leads to muscle contraction. Improper turnover and renewal of acetylcholine receptors contributes to the pathogenesis of myasthenia gravis. In the present study, we demonstrate that endoplasmic reticulum (ER) stress contributes to acetylcholine receptor degradation in C2C12 myocytes. We further show that ER stress promotes acetylcholine receptor endocytosis and lysosomal degradation, which was dampened by blocking endocytosis or treating with lysosome inhibitor. Knockdown of ER stress proteins inhibited acetylcholine receptor endocytosis and degradation, while rescue assay restored its endocytosis and degradation, confirming the effects of ER stress on promoting endocytosis-mediated degradation of junction acetylcholine receptors. Thus, our studies identify ER stress as a factor promoting acetylcholine receptor degradation through accelerating endocytosis in muscle cells. Blocking ER stress and/or endocytosis might provide a novel therapeutic approach for myasthenia gravis. Copyright © 2015 Elsevier B.V. All rights reserved.
1995-01-01
Acetylcholine-evoked currents mediated by activation of nicotinic receptors in rat parasympathetic neurons were examined using whole-cell voltage clamp. The relative permeability of the neuronal nicotinic acetylcholine (nACh) receptor channel to monovalent and divalent inorganic and organic cations was determined from reversal potential measurements. The channel exhibited weak selectivity among the alkali metals with a selectivity sequence of Cs+ > K+ > Rb+ > Na+ > Li+, and permeability ratios relative to Na+ (Px/PNa) ranging from 1.27 to 0.75. The selectivity of the alkaline earths was also weak, with the sequence of Mg2+ > Sr2+ > Ba2+ > Ca2+, and relative permeabilities of 1.10 to 0.65. The relative Ca2+ permeability (PCa/PNa) of the neuronal nACh receptor channel is approximately fivefold higher than that of the motor endplate channel (Adams, D. J., T. M. Dwyer, and B. Hille. 1980. Journal of General Physiology. 75:493-510). The transition metal cation, Mn2+ was permeant (Px/PNa = 0.67), whereas Ni2+, Zn2+, and Cd2+ blocked ACh-evoked currents with half-maximal inhibition (IC50) occurring at approximately 500 microM, 5 microM and 1 mM, respectively. In contrast to the muscle endplate AChR channel, that at least 56 organic cations which are permeable to (Dwyer et al., 1980), the majority of organic cations tested were found to completely inhibit ACh- evoked currents in rat parasympathetic neurons. Concentration-response curves for guanidinium, ethylammonium, diethanolammonium and arginine inhibition of ACh-evoked currents yielded IC50's of approximately 2.5- 6.0 mM. The organic cations, hydrazinium, methylammonium, ethanolammonium and Tris, were measureably permeant, and permeability ratios varied inversely with the molecular size of the cation. Modeling suggests that the pore has a minimum diameter of 7.6 A. Thus, there are substantial differences in ion permeation and block between the nACh receptor channels of mammalian parasympathetic neurons and amphibian skeletal muscle which represent functional consequences of differences in the primary structure of the subunits of the ACh receptor channel. PMID:7561740
Pitman, Michael J; Berzofsky, Craig E; Alli, Opeyemi; Sharma, Sansar
2013-12-01
Optimal management of vocal fold paralysis would entail recurrent laryngeal nerve (RLN) reinnervation resulting in normal vocal fold motion. Unfortunately, RLN reinnervation currently results in a nonfunctional vocal fold due to synkinetic reinnervation. Therapeutic interventions that guide regenerating axons back to the appropriate muscle would prevent synkinesis and restore vocal fold and glottal function. The initial step toward developing these therapies is the elucidation of the embryologic innervation of the larynx. This study aimed to identify the age of occurrence, timing, and pattern of embryologic innervation of the rat larynx, hypothesizing that differences in these parameters exist between distinct laryngeal muscles. Descriptive anatomic study. The larynx of rats aged embryologic day (E) 15, 16, 17, 19, and 21 were harvested and then sectioned. Two rats were used for each age. Sections were colabeled with neuronal class III β-tubulin polyclonal antibody to identify the presence of axons and alexa 488 conjugate α-bungarotoxin to identify the presence of motor endplates. The age at which axons and motor endplates were first present was noted. The position and pattern of the axons and motor endplates was recorded in relation to each other as well as the musculoskeletal anatomy of the larynx. The time at which axons appeared to innervate the medial thyroarytenoid (MTA) muscle, lateral thyroarytenoid (LTA) muscle, and the posterior cricoarytenoid (PCA) muscle was documented. Findings in the rat suggest the RLN reaches the larynx and begins branching by E15. Axons branch dorsally first and reach the PCA muscle before the other muscles. Branching toward the MTA muscle occurs only after axons have reached the LTA muscle. By E19, RLN axons have been guided to and selected their respective muscles with formation of neuromuscular junctions (NMJs) in the PCA, LTA and MTA muscles, though the formation of NMJs in the MTA muscle was comparatively delayed. This study describes the embryologic innervation of the rat larynx and suggests that there are distinct differences in the age of occurrence, timing, and pattern of innervation of the PCA, LTA, and MTA muscles of the rat. These findings lay the foundation for studies investigating the role of guidance cues in RLN axon guidance and the utility of these cues in the treatment of RLN injury via the stimulation of functional, nonsynkinetic reinnervation. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.
2010-04-01
Lett. 89, 232113 (2006). 9. K. Grove-Rasmussen, H. I. Jørgensen, T. Hayashi , P. E. Lindelof, and T. Fujisawa, Nano Lett. 8, 1055 (2008). 10. D. S...Wong, L. Epp and B. D. Hunt, Nanoletters, 6, 942 (2006). 15 18. K. Maehashi, H. Ozaki, Y. Ohno , K. Inoue, K. Matsumoto, S. Seki, and S. Tagawa, Appl...Phys. Lett. 90, 023103 (2007). 19. Y. Ohno , Y. Asai, K. Maehashi, K. Inoue and K. Matsumoto, Appl. Phys. Lett. 94, 053112 (2009). 20. N. Ai, Y.T
Value of Undergraduate Internship Experiences at NOAA: Analysis of Survey Results
NASA Astrophysics Data System (ADS)
Kaplan, M.
2014-12-01
This presentation will examine survey data from over 500 undergraduates who participated in summer internships at NOAA facilities as Ernest F. Hollings Scholars and Educational Partnership Program (EPP) Undergraduate Scholars. NOAA selects over 100 students per year to receive academic support in their junior and senior years and a paid summer internship at any NOAA facility in the country. Scholars are hosted by NOAA mentors who actively oversee summer research activities. Analysis of survey results identified six thematic impacts from the internship experience (McIntosh and Baek, 2013).
Enhancing Peripheral Nerve Regeneration with a Novel Drug Delivering Nerve Conduit
2017-12-01
control group ) or a conduit that released GDNF. The main outcome measures were muscle atrophy, electrophysiology, motor endplate reinnervation...prepared NGF+GDNF ( Control groups ). 8 Gastrocnemius Atrophy The gastrocnemius muscle weight of the GDNF treated group was ~ 60% of the non...experimental side at 10 weeks. GDNF conduit group (49.4±1.4 %) had statistically less muscle atrophy than the control group (65.1±5.1 %) (pɘ.05) at 10
Reinnervation of Paralyzed Muscle by Nerve-Muscle-Endplate Band Grafting
2017-10-01
of the NMEG would be a critical factor influencing outcomes. In our previous studies , a NMEG was im- planted into an aneural region in the recipient...and demonstrated a sustained release. The factors could be released locally in vitro over periods of 2 weeks13,40 or 4 weeks.40 Experimental studies sug...regeneration studies , a number of exogenous neurotrophic factors have been extensively investigated.69 Due to their rela- tively short half-life in vivo
Joint Collaborative Technology Experiment (JCTE)
2010-12-01
Rm = Earth meridian radius Rn = Earth normal radius Compute: α = ψ + β Lat ldg = Lat ant – (r * cos ( α )) / Rm Lon ldg = Lon ant – (r...Watt selectable Comm-Payload Hardware mounted to 24-in x 7-in x 0.25-in (Length x Width x Thick) Aluminum (AL) plate Designed for dual carriage...was installed into a 24-in long by 7.5-in inner diameter fiberglass tube. This integration included modifying two 7.5-in diameter aluminum endplates
Ruven, Carolin; Li, Wen; Li, Heng; Wong, Wai-Man; Wu, Wutian
2017-01-01
Injuries to peripheral nerves are frequent in serious traumas and spinal cord injuries. In addition to surgical approaches, other interventions, such as cell transplantation, should be considered to keep the muscles in good condition until the axons regenerate. In this study, E14.5 rat embryonic spinal cord fetal cells and cultured neural progenitor cells from different spinal cord segments were injected into transected musculocutaneous nerve of 200–300 g female Sprague Dawley (SD) rats, and atrophy in biceps brachii was assessed. Both kinds of cells were able to survive, extend their axons towards the muscle and form neuromuscular junctions that were functional in electromyographic studies. As a result, muscle endplates were preserved and atrophy was reduced. Furthermore, we observed that the fetal cells had a better effect in reducing the muscle atrophy compared to the pure neural progenitor cells, whereas lumbar cells were more beneficial compared to thoracic and cervical cells. In addition, fetal lumbar cells were used to supplement six weeks delayed surgical repair after the nerve transection. Cell transplantation helped to preserve the muscle endplates, which in turn lead to earlier functional recovery seen in behavioral test and electromyography. In conclusion, we were able to show that embryonic spinal cord derived cells, especially the lumbar fetal cells, are beneficial in the treatment of peripheral nerve injuries due to their ability to prevent the muscle atrophy. PMID:28264437
Park, So Young; Jang, So Young; Shin, Yoon Kyoung; Jung, Dong Keun; Yoon, Byeol A; Kim, Jong Kook; Jo, Young Rae; Lee, Hye Jeong
2017-01-01
The vertebrate neuromuscular junction (NMJ) is considered as a “tripartite synapse” consisting of a motor axon terminal, a muscle endplate, and terminal Schwann cells that envelope the motor axon terminal. The neuregulin 1 (NRG1)-ErbB2 signaling pathway plays an important role in the development of the NMJ. We previously showed that Grb2-associated binder 1 (Gab1), a scaffolding mediator of receptor tyrosine kinase signaling, is required for NRG1-induced peripheral nerve myelination. Here, we determined the role of Gab1 in the development of the NMJ using muscle-specific conditional Gab1 knockout mice. The mutant mice showed delayed postnatal maturation of the NMJ. Furthermore, the selective loss of the gab1 gene in terminal Schwann cells produced delayed synaptic elimination with abnormal morphology of the motor endplate, suggesting that Gab1 in both muscles and terminal Schwann cells is required for proper NMJ development. Gab1 in terminal Schwann cells appeared to regulate the number and process elongation of terminal Schwann cells during synaptic elimination. However, Gab2 knockout mice did not show any defects in the development of the NMJ. Considering the role of Gab1 in postnatal peripheral nerve myelination, our findings suggest that Gab1 is a pleiotropic and important component of NRG1 signals during postnatal development of the peripheral neuromuscular system. PMID:28680299
Park, So Young; Jang, So Young; Shin, Yoon Kyoung; Jung, Dong Keun; Yoon, Byeol A; Kim, Jong Kook; Jo, Young Rae; Lee, Hye Jeong; Park, Hwan Tae
2017-06-01
The vertebrate neuromuscular junction (NMJ) is considered as a "tripartite synapse" consisting of a motor axon terminal, a muscle endplate, and terminal Schwann cells that envelope the motor axon terminal. The neuregulin 1 (NRG1)-ErbB2 signaling pathway plays an important role in the development of the NMJ. We previously showed that Grb2-associated binder 1 (Gab1), a scaffolding mediator of receptor tyrosine kinase signaling, is required for NRG1-induced peripheral nerve myelination. Here, we determined the role of Gab1 in the development of the NMJ using muscle-specific conditional Gab1 knockout mice. The mutant mice showed delayed postnatal maturation of the NMJ. Furthermore, the selective loss of the gab1 gene in terminal Schwann cells produced delayed synaptic elimination with abnormal morphology of the motor endplate, suggesting that Gab1 in both muscles and terminal Schwann cells is required for proper NMJ development. Gab1 in terminal Schwann cells appeared to regulate the number and process elongation of terminal Schwann cells during synaptic elimination. However, Gab2 knockout mice did not show any defects in the development of the NMJ. Considering the role of Gab1 in postnatal peripheral nerve myelination, our findings suggest that Gab1 is a pleiotropic and important component of NRG1 signals during postnatal development of the peripheral neuromuscular system.
Liu, Qing-Guang; Liu, Lin; Huang, Qiang-Min; Nguyen, Thi-Tham; Ma, Yan-Tao; Zhao, Jia-Min
2017-01-01
The aims of this study are to investigate the changes in spontaneous electrical activities (SEAs) and in acetylcholine (ACh), acetylcholine receptor (AChR), and acetylcholine esterase (AChE) levels after dry needling at myofascial trigger spots in model rats. Forty-eight male Sprague-Dawley rats were divided into four groups. Thirty-six rats were assigned to three model groups, which underwent MTrSs modeling intervention. Twelve rats were assigned to the blank control (BC) group. After model construction, the 36 model rats were randomly subdivided into three groups according to treatment: MTrSs model control (MC) and two dry needling groups. One dry needling group received puncturing at MTrSs (DN-M), whereas the other underwent puncturing at non-MTrSs (DN-nM). Dry needling treatment will last for two weeks, once a week. SEAs and ACh, AChR, and AChE levels were measured after one-week rest of dry needling treatment. The amplitudes and frequencies of endplate noise (EPN) and endplate spike (EPS) significantly decreased after dry needling treatment in the DN-M group. Moreover, ACh and AChR levels significantly decreased, whereas AChE significantly increased after dry needling treatment in the DN-M group. Dry needling at the exact MTrSs is more effective than dry needling at non-MTrSs.
2017-01-01
Objective The aims of this study are to investigate the changes in spontaneous electrical activities (SEAs) and in acetylcholine (ACh), acetylcholine receptor (AChR), and acetylcholine esterase (AChE) levels after dry needling at myofascial trigger spots in model rats. Materials and Methods Forty-eight male Sprague-Dawley rats were divided into four groups. Thirty-six rats were assigned to three model groups, which underwent MTrSs modeling intervention. Twelve rats were assigned to the blank control (BC) group. After model construction, the 36 model rats were randomly subdivided into three groups according to treatment: MTrSs model control (MC) and two dry needling groups. One dry needling group received puncturing at MTrSs (DN-M), whereas the other underwent puncturing at non-MTrSs (DN-nM). Dry needling treatment will last for two weeks, once a week. SEAs and ACh, AChR, and AChE levels were measured after one-week rest of dry needling treatment. Results The amplitudes and frequencies of endplate noise (EPN) and endplate spike (EPS) significantly decreased after dry needling treatment in the DN-M group. Moreover, ACh and AChR levels significantly decreased, whereas AChE significantly increased after dry needling treatment in the DN-M group. Conclusion Dry needling at the exact MTrSs is more effective than dry needling at non-MTrSs. PMID:28592980
Distribution of vesicular glutamate transporter 1 (VGLUT1) in the mouse esophagus.
Kraus, T; Neuhuber, W L; Raab, M
2007-08-01
In rat and mouse esophagus, vesicular glutamate transporter 2 (VGLUT2) has been demonstrated to identify vagal intraganglionic laminar endings (IGLEs); this has recently also been shown for VGLUT1 in rat esophagus. In this study, we have investigated the distribution of VGLUT1 in the mouse esophagus and compared these results with the recently published data from the rat esophagus. Unexpectedly, we have discovered that VGLUT1 mostly fails to identify IGLEs in the mouse esophagus. This is surprising, since the distribution of VGLUT2 shows comparable results in both species. Confocal imaging has revealed substantial colocalization of VGLUT1 immunoreactivity (-ir) with cholinergic and nitrergic/peptidergic markers within the myenteric neuropil and in both cholinergic and nitrergic myenteric neuronal cell bodies. VGLUT1 and cholinergic markers have also been colocalized in fibers of the muscularis mucosae, whereas VGLUT1 and nitrergic markers have never been colocalized in fibers of the muscularis mucosae, although this does occur in fibers of the muscularis running to motor endplates. Thus, VGLUT1 is contained in the nitrergic innervation of mouse esophageal motor endplates, another difference from the rat esophagus. VGLUT1-ir is therefore present in extrinsic and intrinsic innervation of the mouse esophagus, but the significant differences from the rat indicate species variations concerning the distribution of VGLUTs in the peripheral nervous system.
Human Cartilage Endplate Permeability Varies with Degeneration and Intervertebral Disc Site
DeLucca, John F.; Cortes, Daniel H.; Jacobs, Nathan T.; Vresilovic, Edward J.; Duncan, Randall L.; Elliott, Dawn M.
2016-01-01
Despite the critical functions the human cartilage endplate (CEP) plays in the intervertebral disc, little is known about its structural and mechanical properties and their changes with degeneration. Quantifying these changes with degeneration is important for understanding how the CEP contributes to the function and pathology of the disc. Therefore the objectives of this study were to quantify the effect of disc degeneration on human CEP mechanical properties, determine the influence of superior and inferior disc site on mechanics and composition, and simulate the role of collagen fibers in CEP and disc mechanics using a validated finite element model. Confined compression data and biochemical composition data were used in a biphasic-swelling model to calculate compressive extrafibrillar elastic and permeability properties. Tensile properties were obtained by applying published tensile test data to an ellipsoidal fiber distribution. Results showed that with degeneration CEP permeability decreased 50–60% suggesting that transport is inhibited in the degenerate disc. CEP fibers are organized parallel to the vertebrae and nucleus pulposus and may contribute to large shear strains (0.1–0.2) and delamination failure of the CEP commonly seen in herniated disc tissue. Fiber-reinforcement also reduces CEP axial strains thereby enhancing fluid flux by a factor of 1.8. Collectively, these results suggest that the structure and mechanics of the CEP may play critical roles in the solute transport and disc mechanics. PMID:26874969
Well-differentiated papillary mesothelioma with invasion to the chest wall.
Torii, Ikuko; Hashimoto, Masaki; Terada, Takayuki; Kondo, Nobuyuki; Fushimi, Hiroaki; Shimazu, Kohki; Takeda, Shin-Ichi; Takuwa, Teruhisa; Okumura, Yoshitomo; Sato, Ayuko; Yamamoto, Tadashi; Fukuoka, Kazuya; Tanaka, Fumihiro; Nishigami, Takashi; Nakano, Takashi; Hasegawa, Seiki; Tsujimura, Tohru
2010-02-01
Well-differentiated papillary mesothelioma (WDPM) is an uncommon tumor with a papillary architecture, bland cytologic features, a tendency toward superficial spread without invasion, and good prognosis with prolonged survival. WDPM occurs primarily in the peritoneum of women, but also rarely in the pleura. We here report a case of 48-year-old woman who developed WDPM in the pleura with no history of asbestos exposure. Tumors were multifocal and widespread with a velvety appearance on the surface of parietal and visceral pleurae resected by extrapleural pneumonectomy (EPP). Tumors showed papillary structures with fibrovascular cores and lined by epithelioid cells. Immunohistochemically, these epithelioid tumor cells were positive for epithelial membrane antigen (EMA), a marker of malignant mesothelioma, with more than 50% positive for p53. Tumor cells microinvaded into subpleural parenchyma of the lung and minimally spread to adipose tissues of the mediastinal lesion. In addition, tumor cells invaded into the chest wall with a trabecular or glandular architecture. Based on these findings, this case is pathologically considered as WDPM of the pleura with malignant potential. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.
MAST Upgrade Status and Future Enhancements
NASA Astrophysics Data System (ADS)
Harrison, James; MAST Upgrade Team Team
2017-10-01
The MAST Upgrade spherical tokamak has unique capabilities to address some of the key issues facing the development of fusion energy. Its main objectives are: 1) development of novel exhaust concepts, 2) contribution to the knowledge base for ITER and 3) to explore potential routes to smaller/cheaper fusion reactors. To fulfil these aims, it is equipped with 19 new poloidal field coils and closed divertors with Super-X capability. BT has been increased by 50% and the pulse length and Ip have increased to 5s and 2MA respectively. Auxiliary heating is provided by on and off axis NBI. The gas fuelling system allows for injection from 10 poloidal locations. The divertors are diagnosed with probes, bolometers, Thomson scattering, IR, visible imaging and spectroscopy. Fast ion physics studies are enhanced with a new fast ion loss detector. Following the construction phase, further enhancements are underway including new diagnostics, a cryoplant to serve the cryopumps and 2 additional neutral beams to increase the heating power from 5 to 10MW. Work supported by the RCUK Energy Programme [Grant Number EP/P012450/1] and EURATOM.
Davis, Timothy T; Hynes, Richard A; Fung, Daniel A; Spann, Scott W; MacMillan, Michael; Kwon, Brian; Liu, John; Acosta, Frank; Drochner, Thomas E
2014-11-01
Access to the intervertebral discs from L2-S1 in one surgical position can be challenging. The transpsoas minimally invasive surgical (MIS) approach is preferred by many surgeons, but this approach poses potential risk to neural structures of the lumbar plexus as they course through the psoas. The lumbar plexus and iliac crest often restrict the L4-5 disc access, and the L5-S1 level has not been a viable option from a direct lateral approach. The purpose of the present study was to investigate an MIS oblique corridor to the L2-S1 intervertebral disc space in cadaveric specimens while keeping the specimens in a lateral decubitus position with minimal disruption of the psoas and lumbar plexus. Twenty fresh-frozen full-torso cadaveric specimens were dissected, and an oblique anatomical corridor to access the L2-S1 discs was examined. Measurements were taken in a static state and with mild retraction of the psoas. The access corridor was defined at L2-5 as the left lateral border of the aorta (or iliac artery) and the anterior medial border of the psoas. The L5-S1 corridor of access was defined transversely from the midsagittal line of the inferior endplate of L-5 to the medial border of the left common iliac vessel and vertically to the first vascular structure that crosses midline. The mean access corridor diameters in the static state and with mild psoas retraction, respectively, were as follows: at L2-3, 18.60 mm and 25.50 mm; at L3-4, 19.25 mm and 27.05 mm; and at L4-5, 15.00 mm and 24.45 mm. The L5-S1 corridor mean values were 14.75 mm transversely, from midline to the left common iliac vessel and 23.85 mm from the inferior endplate of L-5 cephalad to the first midline vessel. The oblique corridor allows access to the L2-S1 discs while keeping the patient in a lateral decubitus position without a break in the table. Minimal psoas retraction without significant tendon disruption allowed for a generous corridor to the disc space. The L5-S1 disc space can be accessed from an oblique angle consistently with gentle retraction of the iliac vessels. This study supports the potential of an MIS oblique retroperitoneal approach to the L2-S1 discs.
Aydin, Cristina; Tibbo, Philip G; Ursuliak, Zenovia
2016-06-01
Cannabis use in people with early phase psychosis (EPP) can have a significant impact on long-term outcomes. The purpose of this investigation was to describe current cannabis use treatment practices in English-speaking early intervention services (EISs) in Canada and determine if their services are informed by available evidence. Thirty-five Canadian English-speaking EISs for psychosis were approached to complete a survey through email, facsimile, or online in order to collect information regarding their current cannabis use treatment practices. Data were acquired from 27 of the 35 (78%) programs approached. Only 12% of EISs offered formal services that targeted cannabis use, whereas the majority (63%) of EISs offered informal services for all substance use, not specifically cannabis. In programs with informal services, individual patient psychoeducation (86%) was slightly more common than individual motivational interviewing (MI) (76%) followed by group patient psychoeducation (52%) and information handouts (52%). Thirty-seven percent of EISs offered formal services for substance use, and compared to programs with informal services, more MI, cognitive-behavioural therapy, and family services were offered, with individual treatment modalities more common than groups. No EISs used contingency management, even though it has some preliminary evidence in chronic populations. Evidence-based service implementation barriers included appropriate training and administrative support. While most English-speaking Canadian EIS programs offer individual MI and psychoeducation, which is in line with the available literature, there is room for improvement in cannabis treatment services based on current evidence for both people with EPP and their families. © The Author(s) 2016.
Porphyria Diagnostics – Part 1: A brief overview of the porphyrias
Ramanujam, Vaithamanithi-Mudumbai Sadagopa; Anderson, Karl Elmo
2015-01-01
The porphyria diseases are a group of metabolic disorders caused by abnormal functioning of heme biosynthesis enzymes and characterized by the excessive accumulation and excretion of porphyrins and their precursors. Precisely which of these chemicals builds up depends on the type of porphyria. Porphyria is not a single disease but a group of nine disorders: acute intermittent porphyria (AIP), hereditary coproporphyria (HCP), variegate porphyria (VP), delta-aminolevelunic acid dehyratase deficiency porphyria (ADP), porphyria cutanea tarda (PCT), hepatoerythropoetic porphyria (HEP), congenital erythropoetic porphyria (CEP), erythropoetic protoporphyria (EPP), and X-linked protoporphyria (XLP). Each porphyria results from overproduction of heme precursors secondary to partial deficiency or, in XLP, increased activity of one of the enzymes of heme biosynthesis. Taken together, all forms of porphyria afflict fewer than 200,000 people in the United States. Based on European studies, the prevalence of the most common porphyria, PCT, is 1 in 10,000, the most common acute porphyria, AlP, is about 1 in 20,000, and the most common erythropoietic porphyria, EPP, is estimated at 1 in 50,000 to 75,000. CEP is extremely rare with prevalence estimates of 1 in 1,000,000 or less. Only 6 cases of ADP are documented. The current porphyria literature is very exhaustive and a brief overview of porphyria diseases is essential in order for the reader to better appreciate the relevance of this area of research prior to undertaking biochemical diagnostics procedures. This unit summarizes the current knowledge on the classification, clinical features, etiology, pathogenesis, and genetics of these porphyria diseases. PMID:26132003
1982-12-01
shown in the figure is the cartilagenous end-plate, which is comprised of a hyaline cartilage structure. It serves as a boundary region between a disk...without whose love and support this study would have been impossible. ii S’ Contents Page Preface.................... .. . ..... . .. .. . ... List of...T Vector transpose (’) Differentiation with respect to time xiv I 1.. AFIT/GAE/AA/82D-24 Abstract This study consisted of two phases. During the
Superconducting Electronic Film Structures
1991-02-14
diameter YBCO films are being tested as the endplates in a cylindrical dielectric resonator. The Q and phase noise of the 15 dielectric resonator will...vortex state. Magnus force ne(v, -VL)x O/C is balanced by a drag force an- Josephson 9 demonstrated that the motion of flux vor- tiparallel to the...age of the same sign as in the normal metal [Fig. 3(b)i. the Magnus force Thus a reversal of the sign of the Hall voltage upon enter- "Se ing the mixed
Reinnervation of Paralyzed Muscle by Nerve-Muscle-Endplate Band Grafting
2015-10-01
frozen in melting isopentane cooled with dry ice and cut on a cryostat (Reichert- Jung 1800; Mannheim, Germany) at –25ºC. Some sections were stained with... Jung 1800; Mannheim, Germany) at –25ºC, and stored at –80ºC until staining was performed. For each muscle, the caudal and rostral segments were cut...The stained sections were examined under a Zeiss photomicroscope (Axiophot-2; Carl Zeiss, Gottingen, Germany) and photographed using a digital camera
Aghayev, Emin; Zullig, Nicolas; Diel, Peter; Dietrich, Daniel; Benneker, Lorin M
2014-03-01
Currently, the diagnosis of pedicle screw (PS) loosening is based on a subjectively assessed halo sign, that is, a radiolucent line around the implant wider than 1 mm in plain radiographs. We aimed at development and validation of a quantitative method to diagnose PS loosening on radiographs. Between 11/2004 and 1/2010 36 consecutive patients treated with thoraco-lumbar spine fusion with PS instrumentation without PS loosening were compared with 37 other patients who developed a clinically manifesting PS loosening. Three different angles were measured and compared regarding their capability to discriminate the loosened PS over the postoperative course. The inter-observer invariance was tested and a receiver operating characteristics curve analysis was performed. The angle measured between the PS axis and the cranial endplate was significantly different between the early and all later postoperative images. The Spearman correlation coefficient for the measurements of two observers at each postoperative time point ranged between 0.89 at 2 weeks to 0.94 at 2 months and 1 year postoperative. The angle change of 1.9° between immediate postoperative and 6-month postoperative was 75% sensitive and 89% specific for the identification of loosened screws (AUC = 0.82). The angle between the PS axis and the cranial endplate showed good ability to change in PS loosening. A change of this angle of at least 2° had a relatively high sensitivity and specificity to diagnose screw loosening.
DeLucca, John F.; Peloquin, John M.; Smith, Lachlan J.; Wright, Alexander C.; Vresilovic, Edward J.; Elliott, Dawn M.
2017-01-01
Geometry is an important indicator of disc mechanical function and degeneration. While the geometry and associated degenerative changes in the nucleus pulposus and the annulus fibrosus are well-defined, the geometry of the cartilage endplate (CEP) and its relationship to disc degeneration are unknown. The objectives of this study were to quantify CEP geometry in three dimensions using an MRI FLASH imaging sequence and evaluate relationships between CEP geometry and age, degeneration, spinal level, and overall disc geometry. To do so, we assessed the MRI-based measurements for accuracy and repeatability. Next, we measured CEP geometry across a larger sample set and correlated CEP geometric parameters to age, disc degeneration, level, and disc geometry. The MRI-based measures resulted in thicknesses (0.3–1 mm) that are comparable to prior measurements of CEP thickness. CEP thickness was greatest at the anterior/posterior (A/P) margins and smallest in the center. The CEP A/P thickness, axial area, and lateral width decreased with age but were not related to disc degeneration. Age-related, but not degeneration-related, changes in geometry suggest that the CEP may not follow the progression of disc degeneration. Ultimately, if the CEP undergoes significant geometric changes with aging and if these can be related to low back pain, a clinically feasible translation of the FLASH MRI-based measurement of CEP geometry presented in this study may prove a useful diagnostic tool. PMID:27232974
A Radiographic Measurement of the Anterior Epidural Space at L4-5 Disc Level.
Xu, Rui-Sheng; Wu, Jie-Shi; Lu, Hai-Dan; Zhu, Hao-Gang; Li, Xia; Dong, Jian; Yuan, Feng-Lai
2017-05-01
To observe the morphology character of the anterior epidural space at the L 4-5 disc level and to provide an anatomical basis for safely and accurately performing a percutaneous endoscopic lumbar discectomy (PELD). Fifty-five cases with L 5 S 1 lumbar disc herniation were included in this study, and cases with L 4-5 disease were excluded. When the puncture needle reached the epidural space at the L 5 S 1 level, iohexol was injected at the pressure of 50 cm H 2 O during the PELD, then C-Arm fluoroscopy was used to obtain standard lumbar frontal and lateral images. The widths of epidural space at the level of the L 4 lower endplate, the L 5 upper endplate, as well as the middle point of the L 4-5 disc were measured from the lumbar lateral X-ray film. Epidural space at the L 4-5 disc plane performs like a trapezium chart with a short side at the head end and a long side at the tail end in the lumbar lateral X-ray radiograph, while the average widths of epidural space were 10.2 ± 2.5, 12.3 ± 2.3, and 13.8 ± 2.6 mm at the upper, middle, and lower level of the L 4-5 disc. Understanding the morphological characteristics of epidural space will contribute to improving the safety of the tranforaminal percutaneous endoscopy technique. © 2017 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.
Human cartilage endplate permeability varies with degeneration and intervertebral disc site.
DeLucca, John F; Cortes, Daniel H; Jacobs, Nathan T; Vresilovic, Edward J; Duncan, Randall L; Elliott, Dawn M
2016-02-29
Despite the critical functions the human cartilage endplate (CEP) plays in the intervertebral disc, little is known about its structural and mechanical properties and their changes with degeneration. Quantifying these changes with degeneration is important for understanding how the CEP contributes to the function and pathology of the disc. Therefore the objectives of this study were to quantify the effect of disc degeneration on human CEP mechanical properties, determine the influence of superior and inferior disc site on mechanics and composition, and simulate the role of collagen fibers in CEP and disc mechanics using a validated finite element model. Confined compression data and biochemical composition data were used in a biphasic-swelling model to calculate compressive extrafibrillar elastic and permeability properties. Tensile properties were obtained by applying published tensile test data to an ellipsoidal fiber distribution. Results showed that with degeneration CEP permeability decreased 50-60% suggesting that transport is inhibited in the degenerate disc. CEP fibers are organized parallel to the vertebrae and nucleus pulposus and may contribute to large shear strains (0.1-0.2) and delamination failure of the CEP commonly seen in herniated disc tissue. Fiber-reinforcement also reduces CEP axial strains thereby enhancing fluid flux by a factor of 1.8. Collectively, these results suggest that the structure and mechanics of the CEP may play critical roles in the solute transport and disc mechanics. Copyright © 2016 Elsevier Ltd. All rights reserved.
Numerical study on air turbines with enhanced techniques for OWC wave energy conversion
NASA Astrophysics Data System (ADS)
Cui, Ying; Hyun, Beom-Soo; Kim, Kilwon
2017-10-01
In recent years, the oscillating water column (OWC) wave energy converter, which can capture wave energy from the ocean, has been widely applied all over the world. As the essential part of the OWC system, the impulse and Wells turbines are capable of converting the low pressure pneumatic energy into the mechanical shaft power. As an enhanced technique, the design of endplate or ring attached to the blade tip is investigated numerically in this paper. 3D numerical models based on a CFD-software FLUENT 12.0 are established and validated by the corresponding experimental results from the reports of Setoguchi et al. (2004) and Takao et al. (2001). Then the flow fields and non-dimensional evaluating coefficients are calculated and analyzed under steady conditions. Results show that the efficiency of impulse turbine with ring can reach up to 0.49 when ϕ=1, which is 4% higher than that in the cases for the endplate-type and the original one. And the ring-type Wells turbine with fixed guide vanes shows the best performance with the maximal efficiency of 0.55, which is 22% higher than that of the original one. In addition, the quasi-steady analysis is used to calculate the mean efficiency and output-work of a wave cycle under sinusoidal flow condition. Taking all together, this study provides support for structural optimization of impulse turbine and Wells turbine in the future.
A 6-DOF parallel bone-grinding robot for cervical disc replacement surgery.
Tian, Heqiang; Wang, Chenchen; Dang, Xiaoqing; Sun, Lining
2017-12-01
Artificial cervical disc replacement surgery has become an effective and main treatment method for cervical disease, which has become a more common and serious problem for people with sedentary work. To improve cervical disc replacement surgery significantly, a 6-DOF parallel bone-grinding robot is developed for cervical bone-grinding by image navigation and surgical plan. The bone-grinding robot including mechanical design and low level control is designed. The bone-grinding robot navigation is realized by optical positioning with spatial registration coordinate system defined. And a parametric robot bone-grinding plan and high level control have been developed for plane grinding for cervical top endplate and tail endplate grinding by a cylindrical grinding drill and spherical grinding for two articular surfaces of bones by a ball grinding drill. Finally, the surgical flow for a robot-assisted cervical disc replacement surgery procedure is present. The final experiments results verified the key technologies and performance of the robot-assisted surgery system concept excellently, which points out a promising clinical application with higher operability. Finally, study innovations, study limitations, and future works of this present study are discussed, and conclusions of this paper are also summarized further. This bone-grinding robot is still in the initial stage, and there are many problems to be solved from a clinical point of view. Moreover, the technique is promising and can give a good support for surgeons in future clinical work.
Dubory, Arnaud; Bouloussa, Houssam; Riouallon, Guillaume; Wolff, Stéphane
2017-12-01
Widely used in traumatic pelvic ring fractures, the iliosacral (IS) screw technique for spino-pelvic fixation remains anecdotal in adult spinal deformity. The objective of this study was to assess anatomical variability of the adult upper sacrum and to provide a user guide of spino-pelvic fixation with IS screws in adult spinal deformity. Anatomical variability of the upper sacrum according to age, gender, height and weight was sought on 30 consecutive pelvic CT-scans. Thus, a user guide of spino-pelvic fixation with IS screws was modeled and assessed on ten CT-scans as described below. Two invariable landmarks usable during the surgical procedure were defined: point A (corresponding to the connector binding the IS screw to the spinal rod), equidistant from the first posterior sacral hole and the base of the S1 articular facet and 10 mm-embedded into the sacrum; point B (corresponding to the tip of the IS screw) located at the junction of the anterior third and middle third of the sacral endplate in the sagittal plane and at the middle of the endplate in the coronal plane. Point C corresponded to the intersection between the A-B direction and the external facet of the iliac wing. Three-dimensional reconstructions modeling the IS screw optimal direction according to the A-B-C straight line were assessed. Age had no effect on the anatomy of the upper sacrum. The distance between the base of the S1 superior articular facet and the top of the first posterior sacral hole was correlated with weight (r = 0.6; 95% CI [0.6-0.9]); p < 0.001). Sacral end-plate thickness increased for male patients (p < 0.001) and was strongly correlated with height (r = 0.6; 95% CI [0.29-0.75]); p < 0.001) and weight (r = 0.8; 95% CI [0.6-0.9]); p < 0.001). The thickness of the inferior part of the S1 vertebral body increased in male patients (p < 0.001). Other measured parameters slightly varied according to gender, height and weight. Simulating the described technique of pelvic fixation, no misplaced IS screw was found whatever the age, gender and morphologic parameters. This user guide of spinopelvic fixation with IS screws seems to be reliable and reproducible independently of age, gender and morphologic characteristics but needs clinical assessment. Level IV.
Number of junctional acetylcholine receptors: control by neural and muscular influences in the rat.
Andreose, J S; Fumagalli, G; Lømo, T
1995-03-01
1. The number of acetylcholine receptors (AChRs) per neuromuscular junction in soleus muscles of adult rats was estimated from counts of 125I-alpha-bungarotoxin binding sites. The muscles were either denervated, denervated and electrically stimulated, paralysed by botulinum toxin (BoTX), or paralysed by tetrodotoxin (TTX). 2. After denervation, the number of junctional AChRs was normal after 18 days and then fell to 54 and 35% of normal after 33 and 57 days, respectively. 3. Direct high frequency muscle stimulation (100 Hz) maintained a normal number of junctional AChRs for at least 2 months when the stimulation started on the day of denervation. When the stimulation was started progressively later, the effect of the stimulation on AChR number disappeared within about a week. The disappearance was gradual and appeared to affect all the muscle fibres equally. 4. Stimulation at 100 Hz, starting on the day of denervation and stopping after 18 days, did not prevent the endplates from losing AChRs during the subsequent 15 days without stimulation. Thus 100 Hz stimulation and innervation are not equivalent in their effects on junctional AChR number. 5. Direct low frequency muscle stimulation from the day of denervation did not maintain a normal number of junctional AChRs, as the number of AChRs fell to 70 and 62% of normal after 33 days of stimulation at 20 and 10 Hz, respectively. 6. Endplates paralysed by BoTX or TTX for 33 days lost about as many junctional AChRs (54 and 55%) as endplates denervated for 33 days (46%). Direct stimulation at 100 Hz during the last 15 days of BoTX treatment reduced but did not prevent this AChR loss (36% loss at 33 days). 7. The results show that when motor nerve terminals in rat soleus muscles are removed by axotomy, they leave a 'trace' which, in conjunction with appropriate muscle stimulation, can maintain a normal number of AChRs in the postsynaptic region. In non-stimulated muscles the trace responsible for this maintenance disappears within about a week. In stimulated muscles it persists for at least 2 months. From indirect evidence it appears that the trace is a factor, or the postsynaptic effect of a factor, released by impulse activity in the nerve, and that its degradation after denervation is accelerated by the acute effects of nerve degeneration.
Report on FY15 Alloy 617 SMT Creep-Fatigue Test Results
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Yanli; Jetter, Robert I.; Baird, Seth T.
For the temperature range of 990-950C, Alloy 617 is a candidate IHX structural material for high temperature gas reactors (HTGRs) because of its high temperature creep properties. Also, its superior strength over a broad temperature range also offers advantages for certain component applications. In order for the designers to be able to use Alloy 617 for these high temperature components, Alloy 617 has to be approved for use in Section III (the nuclear section) of the ASME (American Society of Mechanical Engineers) Boiler and Pressure Vessel Code. A plan has been developed to propose a Code Case for use ofmore » Alloy 617 at elevated temperature in Section III of the ASME Code by September 2015. There has not been a new high temperature material approved for use in Section III for almost 20 years. The Alloy 617 Code Case effort would lead the way to establish a path for Code qualification of new high temperature materials of interest to other advanced SMRs. Creep-fatigue at elevated temperatures is the most damaging structural failure mode. In the past 40 years significant efforts have been devoted to the elevated temperature Code rule development in Section III, Subsection NH* of the ASME Boiler and Pressure Vessel Code, to ascertain conservative structural designs to prevent creep-fatigue failure. The current Subsection NH creep-fatigue procedure was established by the steps of (1) analytically obtaining a detailed stress-strain history, (2) comparing the stress and strain components to cyclic test results deconstructed into stress and strain quantities, and (3) recombining the results to obtain a damage function in the form of the so-called creep-fatigue damage-diagram. The deconstruction and recombination present difficulties in evaluation of test data and determination of cyclic damage in design. The uncertainties in these steps lead to the use of overly conservative design factors in the current creep-fatigue procedure. In addition, and of major significance to the viability of the Alloy 617 Code Case, the use of the current elastic analysis based rules in Subsection NH for the evaluation of strain limits (a precursor for the creep-fatigue rules) and the creep-fatigue rules themselves have been deemed inappropriate for Alloy 617 at temperatures above 650C (Corum and Brass, 1991). The rationale for this exclusion is that at higher temperatures it is not feasible to decouple plasticity and creep, which is the basis for the current simplified rules. This temperature, 650C, is well below the temperature range of interest for this material for the High Temperature Gas Cooled Reactor (HTGR) as well as the VHTR. The only current alternative is, thus, a full inelastic analysis which requires sophisticated material models which have not yet been formulated and verified. To address the prohibition on the use of current methods at very high temperatures, proposed Code rules have been developed which are based on the use of elastic-perfectly plastic (E-PP) analysis methods and which are expected to be applicable to very high temperatures. To provide data to implement the proposed rules and to verify their application, a series of tests have been initiated. One test concept, the Simplified Model Test (SMT), takes into account the stress and strain redistribution in real structures by including representative follow-up characteristics in the test specimen. The correlation parameter between test and design is the elastically calculated strain, and the dependent test variable is the observed cycles to failure. Although the initial priority for the SMT approach is to generate data to support validation of the E-PP Code Case for evaluation of creep-fatigue damage, the broader goal of the SMT approach is to develop a methodology for evaluation of creep fatigue damage which is simpler to implement than the current complex rules and applicable to the full temperature range from ambient conditions to the very high temperature creep regime of 900-950C. Also, guidance has been received from ASME Code committees that the proposed EPP methodology for evaluation of creep-fatigue damage should be extended to the other Subsection NH materials to the extent feasible. Thus, the scope of testing has been expanded to include SS304H and SS316H. This report describes the SMT approach and the development of testing capability to conduct SMT experiments on Alloy 617 and 304H and 316H and stainless steels. These SMT specimen data are also representative of component loading conditions and have been used as part of the verification of the proposed elastic-perfectly plastic Code Cases. Results from the SMT tests on both Alloy 617 and SS316H were compared to the predictions from the EPP Creep-Fatigue Code Case. Two different comparisons were made; one based on design life equal to the test duration and the other with an acceptable design life determined from the EPP Code Case procedure. The latter approach permits the determination of...« less
Modeling Plasma Turbulence and Flows in LAPD using BOUT++
NASA Astrophysics Data System (ADS)
Friedman, B.; Carter, T. A.; Schaffner, D.; Popovich, P.; Umansky, M. V.; Dudson, B.
2010-11-01
A Braginskii fluid model of plasma turbulence in the BOUT code has recently been applied to LAPD at UCLA [1]. While these initial simulations with a reduced model and periodic axial boundary conditions have shown good agreement with measurements (e.g. power spectrum, correlation lengths), these simulations have lacked physics essential for modeling self-consistent, quantitatively correct flows. In particular, the model did not contain parallel plasma flow induced by sheath boundary conditions, and the axisymmetric radial electric field was not consistent with experiment. This work addresses these issues by extending the simulation model in the BOUT++ code [2], a more advanced version of BOUT. Specifically, end-plate sheath boundary conditions are added, as well as equations to evolve electron temperature and parallel ion velocity. Finally, various techniques are used to attempt to match the experimental electric potential profile, including fixing an equilibrium profile, fixing the radial boundaries, and adding an angular momentum source. [4pt] [1] Popovich et al., http://arxiv.org/abs/1005.2418 (2010).[0pt] [2] Dudson et al., Computer Physics Communications 180 (2009).
DOE Office of Scientific and Technical Information (OSTI.GOV)
Krayenbuehl, Jerome Dipl.Phys. E.T.H.; Oertel, Susanne; Davis, J. Bernard
Purpose: The optimal technique for postoperative radiotherapy (RT) after extrapleural pleuropneumonectomy (EPP) of malignant pleural mesothelioma (MPM) remains debated. Methods and Materials: The data from 8 right-sided and 9 left-sided consecutive cases of MPM treated with RT after radical EPP were reviewed. Of the 17 patients, 8 had been treated with three-dimensional (3D) conformal RT (3D-CRT) and 9 with intensity-modulated RT (IMRT) with 6-MV photons. The clinical outcome and adverse events were assessed. For comparative planning, each case was replanned with 3D-CRT using photons and electrons or with IMRT. Homogeneity, doses to the organs at risk, and target volume coveragemore » were analyzed. Results: Both techniques yielded acceptable plans. The dose coverage and homogeneity of IMRT increased by 7.7% for the first planning target volume and 9.7% for the second planning target volume, ensuring {>=}95% of the prescribed dose compared with 3D-CRT (p < 0.01). Compared with 3D-CRT, IMRT increased the dose to the contralateral lung, with an increase in the mean lung dose of 7.8 Gy and an increase in the volume receiving 13 Gy and 20 Gy by 20.5% and 7.2%, respectively (p < 0.01). A negligible dose increase to the contralateral kidney and liver was observed. No differences were seen for the spinal cord and ipsilateral kidney. Two adverse events of clinical relevant lung toxicity were observed with IMRT. Conclusion: Intensity-modulated RT and 3D-CRT are both suitable for adjuvant RT. IMRT improves the planning target volume coverage but delivered greater doses to the organs at risk. Rigid dose constraints for the lung should be respected.« less
Zhang, Li; Li, Xu-Hui; Gao, Zhen; Shen, Si; Liang, Xiao-Gui; Zhao, Xue; Lin, Shan; Zhou, Shun-Li
2017-09-01
Abscisic acid (ABA) accumulates in plants under drought stress, but views on the role of ABA in kernel formation and abortion are not unified. The response of the developing maize kernel to exogenous ABA was investigated by excising kernels from cob sections at four days after pollination and culturing in vitro with different concentrations of ABA (0, 5, 10, 100μM). When ABA was applied at the early post-pollination stage (EPPS), significant weight loss was observed at high ABA concentration (100μM), which could be attributed to jointly affected sink capacity and activity. Endosperm cells and starch granules were decreased significantly with high concentration, and ABA inhibited the activities of soluble acid invertase and acid cell wall invertase, together with earlier attainment of peak values. When ABA was applied at the middle post-pollination stage (MPPS), kernel weight was observably reduced with high concentration and mildly increased with low concentration, which was regulated due to sink activity. The inhibitory effect of high concentration and the mild stimulatory effect of low concentration on sucrose synthase and starch synthase activities were noted, but a peak level of ADP-glucose pyrophosphorylase (AGPase) was stimulated in all ABA treatments. Interestingly, AGPase peak values were advanced by low concentration and postponed by high concentration. In addition, compared with the control, the weight of low ABA concentration treatments were not statistically significant at the two stages, whereas weight loss from high concentration applied at EPPS was considerably obvious compared with that of the MPPS, but neither led to kernel abortion. The temporal- and dose-dependent impacts of ABA reveal a complex process of maize kernel growth and development. Copyright © 2017 Elsevier GmbH. All rights reserved.
Cunha, A T M; Carvalho, J O; Kussano, N R; Martins, C F; Mourão, G B; Dode, M A N
2016-12-01
In this study we examined quality, longevity and ability of epididymal sperm (EP) to bind to oviduct explants (OE) after cooling and cryopreservation. Ejaculated (EJ) and EP sperm from seven bulls were evaluated before, during and after cryopreservation for total (TM), progressive motility (PM), sperm morphology, plasma membrane integrity (PMI) and acrosome integrity (ACI). For longevity, cryopreserved EP, EJ and a third group of cells in which EP spermatozoa were incubated with seminal plasm (SP) for 10 min after thawing (EPP group), were compared, and the groups were analyzed at 0, 3, 6, and 24 h for all parameters. Sperm from each group were co-incubated with OE for 30 min, 6 h, and 24 h for binding evaluation. Data were analyzed by the generalized linear models SAS 9.1 (P < 0.05). After cooling, EP displayed higher TM, higher PMI, and higher ACI (P < 0.05) than EJ. No differences were noted in the percentage of spermatozoa with PMI and AI between EJ and EP for fresh, cooled or cryopreserved sperm. However, a reduction in motility occurred in the EJ sperm after cooling, while in EP group such reduction occurred only after cryopreservation. At 6 h of incubation EP and EPP had higher PMI and ACI than EJ (P < 0.05). The number of spermatozoa bound to OE was similar P > 0.05) for all groups either at 30 min or 24 h. We conclude that EP are more resistant to cooling than EJ, and can bind to OE similarly to EJ. Copyright © 2016 Elsevier Inc. All rights reserved.
Lumbar Spine Musculoskeletal Physiology and Biomechanics During Simulated Military Operations
2015-06-01
decreases at a ll l eve l s except L1L2 when s i tting . Even anteri or/posteri or d i stri but i on o f l oad maintains whole lumbar lordosis as load...more forward. Data shown is mean ± STD. Figure 4. Cobb angle was measured in each position to assess lumbar lordosis . A.) Sagittal Cobb angle is...c C/)..C C) 0 () -(/) (!) !.... (!) .Q 0, !.... (!) ~Ŕ c- =<D ro-.....,e> :!:C O><( ro..c Cl)..c 0 () Lordosis Kyphosis endplate
Front-end electronics of the Belle II drift chamber
NASA Astrophysics Data System (ADS)
Shimazaki, Shoichi; Taniguchi, Takashi; Uchida, Tomohisa; Ikeno, Masahiro; Taniguchi, Nanae; Tanaka, Manobu M.
2014-01-01
This paper describes the performance of the Belle II central drift chamber (CDC) front-end electronics. The front-end electronics consists of a current sensitive preamplifier, a 1/t cancellation circuit, baseline restorers, a comparator for timing measurement and an analog buffer for the dE/dx measurement on a CDC readout card. The CDC readout card is located on the endplate of the CDC. Mass production will be completed after the performance of the chip is verified. The electrical performance and results of a neutron/gamma-ray irradiation test are reported here.
Measurement of the Heat Capacity of He-II Under a Heat Current Near the Lambda Transition
NASA Technical Reports Server (NTRS)
Harter, Alexa W.; Lee, Richard A. M.; Chui, Talso C. P.; Goodstein, David L.
2000-01-01
We present preliminary measurements of the heat capacity of superfluid helium-4 under an applied heat current near the lambda transition. The calorimeter is a standard cylindrical thermal conductivity cell with a 0.6 mm gap between two copper endplates. The sidewall is made of stainless steel. A heat current density in the range of 1 to 4 microW/sq cm is applied through the helium sample while a pulse method is used to measure the heat capacity. Temperature changes are recorded with high-resolution thermometers (HRTs) located on the top and bottom endplates. Corrections are made to the readings of the HRTs to account for the Kapitza boundary resistance and the anomalous Kapitza boundary resistance. After the corrections, both the top and the bottom HRTs. give the same heat capacity values. The heat capacity is found to be much larger than the prediction of recent theories. We also plotted our data on a scaled plot to test the prediction of scaling by the theories. The result and its interpretation will be presented. The cell height was deliberately made to be thin to reduce the effects of gravity. Nonetheless, gravity is expected to have significant effects on the heat capacity data in the temperature range of our measurement. A space experiment would remove this unwanted gravity effect and allow the true physics to be examined. Moreover, in the absence of gravity, a deeper cell can be used allowing HRTs to be mounted on to the sidewall providing direct measurements of the helium temperature, unaffected by the anomalous Kapitza boundary resistance.
Krause Neto, Walter; Silva, Wellington de Assis; Ciena, Adriano P.; de Souza, Romeu R.; Anaruma, Carlos A.; Gama, Eliane F.
2017-01-01
The present study aimed to analyze the morphology of the peripheral nerve, postsynaptic compartment, skeletal muscles and weight-bearing capacity of Wistar rats at specific ages. Twenty rats were divided into groups: 10 months-old (ADULT) and 24 months-old (OLD). After euthanasia, we prepared and analyzed the tibial nerve using transmission electron microscopy and the soleus and plantaris muscles for cytofluorescence and histochemistry. For the comparison of the results between groups we used dependent and independent Student's t-test with level of significance set at p ≤ 0.05. For the tibial nerve, the OLD group presented the following alterations compared to the ADULT group: larger area and diameter of both myelinated fibers and axons, smaller area occupied by myelinated and unmyelinated axons, lower numerical density of myelinated fibers, and fewer myelinated fibers with normal morphology. Both aged soleus and plantaris end-plate showed greater total perimeter, stained perimeter, total area and stained area compared to ADULT group (p < 0.05). Yet, aged soleus end-plate presented greater dispersion than ADULT samples (p < 0.05). For the morphology of soleus and plantaris muscles, density of the interstitial volume was greater in the OLD group (p < 0.05). No statistical difference was found between groups in the weight-bearing tests. The results of the present study demonstrated that the aging process induces changes in the peripheral nerve and postsynaptic compartment without any change in skeletal muscles and ability to carry load in Wistar rats. PMID:29326543
Jaremko, Jacob Lester; Siminoski, Kerry; Firth, Gregory; Matzinger, Mary Ann; Shenouda, Nazih; Konji, Victor N.; Roth, Johannes; Sbrocchi, Anne Marie; Reed, Martin; O’Brien, Kathleen; Nadel, Helen; McKillop, Scott; Kloiber, Reinhard; Dubois, Josée; Coblentz, Craig; Charron, Martin; Ward, Leanne M.
2015-01-01
Children with glucocorticoid-treated illnesses are at risk for osteoporotic vertebral fractures and growing awareness has led to increased monitoring for these fractures. However scant literature describes developmental changes in vertebral morphology that can mimic fractures. The goal of this paper is to aid in distinguishing between normal variants and fractures. We illustrate differences using lateral spine radiographs obtained annually from children recruited to the Canada-wide STeroid-Associated Osteoporosis in the Pediatric Population (STOPP) observational study, in which 400 children with glucocorticoid-treated leukemia, rheumatic disorders, and nephrotic syndrome were enrolled near glucocorticoid initiation and followed prospectively for 6 years. Normal variants mimicking fractures exist in all regions of the spine and fall into two groups. The first group comprises variants mimicking pathological vertebral height loss, including not-yet-ossified vertebral apophyses superiorly and inferiorly which can lead to a vertebral shape easily over-interpreted as anterior wedge fracture, physiologic beaking, and spondylolisthesis associated with shortened posterior vertebral height. The second group includes variants mimicking other radiologic signs of fractures: anterior vertebral artery groove resembling an anterior buckle fracture, Cupid’s bow balloon disk morphology, Schmorl nodes mimicking concave endplate fractures, and parallax artifact resembling endplate interruption or biconcavity. If an unexpected vertebral body contour is detected, careful attention to its location, detailed morphology, and (if available) serial changes over time may clarify whether it is a fracture requiring change in management or simply a normal variant. Awareness of the variants described in this paper can improve accuracy in the diagnosis of pediatric vertebral fractures. PMID:25828359
Why do some intervertebral discs degenerate, when others (in the same spine) do not?
Adams, Michael A; Lama, Polly; Zehra, Uruj; Dolan, Patricia
2015-03-01
This review suggests why some discs degenerate rather than age normally. Intervertebral discs are avascular pads of fibrocartilage that allow movement between vertebral bodies. Human discs have a low cell density and a limited ability to adapt to mechanical demands. With increasing age, the matrix becomes yellowed, fibrous, and brittle, but if disc structure remains intact, there is little impairment in function, and minimal ingrowth of blood vessels or nerves. Approximately half of old lumbar discs degenerate in the sense of becoming physically disrupted. The posterior annulus and lower lumbar discs are most affected, presumably because they are most heavily loaded. Age and genetic inheritance can weaken discs to such an extent that they are physically disrupted during everyday activities. Damage to the endplate or annulus typically decompresses the nucleus, concentrates stress within the annulus, and allows ingrowth of nerves and blood vessels. Matrix disruption progresses by mechanical and biological means. The site of initial damage leads to two disc degeneration "phenotypes": endplate-driven degeneration is common in the upper lumbar and thoracic spine, and annulus-driven degeneration is common at L4-S1. Discogenic back pain can be initiated by tissue disruption, and amplified by inflammation and infection. Healing is possible in the outer annulus only, where cell density is highest. We conclude that some discs degenerate because they are disrupted by excessive mechanical loading. This can occur without trauma if tissues are weakened by age and genetic inheritance. Moderate mechanical loading, in contrast, strengthens all spinal tissues, including discs. © 2014 Wiley Periodicals, Inc.
Caudal lumbar vertebral fractures in California Quarter Horse and Thoroughbred racehorses.
Collar, E M; Zavodovskaya, R; Spriet, M; Hitchens, P L; Wisner, T; Uzal, F A; Stover, S M
2015-09-01
To gain insight into the pathophysiology of equine lumbar vertebral fractures in racehorses. To characterise equine lumbar vertebral fractures in California racehorses. Retrospective case series and prospective case-control study. Racehorse post mortem reports and jockey injury reports were retrospectively reviewed. Vertebral specimens from 6 racehorses affected with lumbar vertebral fractures and 4 control racehorses subjected to euthanasia for nonspinal fracture were assessed using visual, radiographic, computed tomography and histological examinations. Lumbar vertebral fractures occurred in 38 Quarter Horse and 29 Thoroughbred racehorses over a 22 year period, primarily involving the 5th and/or 6th lumbar vertebrae (L5-L6; 87% of Quarter Horses and 48% of Thoroughbreds). Lumbar vertebral fractures were the third most common musculoskeletal cause of death in Quarter Horses and frequently involved a jockey injury. Lumbar vertebral specimens contained anatomical variations in the number of vertebrae, dorsal spinous processes and intertransverse articulations. Lumbar vertebral fractures examined in 6 racehorse specimens (5 Quarter Horses and one Thoroughbred) coursed obliquely in a cranioventral to caudodorsal direction across the adjacent L5-L6 vertebral endplates and intervertebral disc, although one case involved only one endplate. All cases had evidence of abnormalities on the ventral aspect of the vertebral bodies consistent with pre-existing, maladaptive pathology. Lumbar vertebral fractures occur in racehorses with pre-existing pathology at the L5-L6 vertebral junction that is likely predisposes horses to catastrophic fracture. Knowledge of these findings should encourage assessment of the lumbar vertebrae, therefore increasing detection of mild vertebral injuries and preventing catastrophic racehorse and associated jockey injuries. © 2014 EVJ Ltd.
Assessment of scoliosis by direct measurement of the curvature of the spine
NASA Astrophysics Data System (ADS)
Dougherty, Geoff; Johnson, Michael J.
2009-02-01
We present two novel metrics for assessing scoliosis, in which the geometric centers of all the affected vertebrae in an antero-posterior (A-P) radiographic image are used. This is in contradistinction to the existing methods of using selected vertebrae, and determining either their endplates or the intersections of their diagonals, to define a scoliotic angle. Our first metric delivers a scoliotic angle, comparable to the Cobb and Ferguson angles. It measures the sum of the angles between the centers of the affected vertebrae, and avoids the need for an observer to decide on the extent of component curvatures. Our second metric calculates the normalized root-mean-square curvature of the smoothest path comprising piece-wise polynomial splines fitted to the geometric centers of the vertebrae. The smoothest path is useful in modeling the spinal curvature. Our metrics were compared to existing methods using radiographs from a group of twenty subjects with spinal curvatures of varying severity. Their values were strongly correlated with those of the scoliotic angles (r = 0.850 - 0.886), indicating that they are valid surrogates for measuring the severity of scoliosis. Our direct use of positional data removes the vagaries of determining variably shaped endplates, and circumvented the significant interand intra-observer errors of the Cobb and Ferguson methods. Although we applied our metrics to two-dimensional (2- D) data in this paper, they are equally applicable to three-dimensional (3-D) data. We anticipate that they will prove to be the basis for a reliable 3-D measurement and classification system.
Comprehensive evaluation of long-term hydrological data sets: Constraints of the Budyko framework
NASA Astrophysics Data System (ADS)
Greve, Peter; Orlowsky, Boris; Seneviratne, Sonia I.
2013-04-01
An accurate estimate of the climatological land water balance is essential for a wide range of socio-economical issues. Despite the simplicity of the underlying water balance equation, its individual variables are of complex nature. Global estimates, either derived from observations or from models, of precipitation (P ) and especially evapotranspiration (ET) are characterized by high uncertainties. This leads to inconsistent results in determining conditions related to the land water balance and its components. In this study, we consider the Budyko framework as a constraint to evaluate long-term hydrological data sets within the period from 1984 to 2005. The Budyko framework is a well established empirically based relationsship between ET-P and Ep-P , with Ep being the potential evaporation. We use estimates of ET associated with the LandFlux-EVAL initiative (Mueller et. al., 2012), either derived from observations, CMIP5 models or land-surface models (LSMs) driven with observation-based forcing or atmospheric reanalyses. Data sets of P comprise all commonly used global observation-based estimates. Ep is determined by methods of differing complexity with recent global temperature and radiation data sets. Based on this comprehensive synthesis of data sets and methods to determine Ep, more than 2000 possible combinations for ET-P in conjunction with Ep-P are created. All combinations are validated against the Budyko curve and against physical limits within the Budyko phase space. For this purpose we develop an error measure based on the root mean square error which combines both constraints. We find that uncertainties are mainly induced by the ET data sets. In particular, reanalysis and CMIP5 data sets are characterized by low realism. The realism of LSMs is further not primarily controlled by the forcing, as different LSMs driven with the same forcing show significantly different error measures. Our comprehensive approach is thus suitable to detect uncertainties associated with individual data sets. Furthermore, combinations performing well within the Budyko phase space are identified and could be used for future studies, like e.g. to investigate decadal changes of the land water balance. B. MUELLER, M. HIRSCHI, C. JIMENEZ, P. CIAIS, P.A. DIRMEYER, A.J. DOLMAN, J.B. FISHER, Z. GUO, M. JUNG, F. LUDWIG, F. MAIGNAN, D. MIRALLES, M.F. MCCABE, M. REICHSTEIN, J. SHEELD, K. WANG, E.F.WOOD, Y. ZHANG, S.I. SENEVIRATNE (2012): Benchmark products for land evapotranspiration: LandFlux-EVAL multi-dataset synthesis, Hydrol. Earth Syst. Sci., submitted.
Bistatic Radar Cross Section of a Perfectly Conducting Rhombus-Shaped Flat Plate
1990-05-02
1 -3]. A physical optics formulation for the bistatic scattering of...7ESP13900 2 12X1*4*0.’.. MAO, (O5/M**2) oss- 1 ’ ESP13k10 3 SX,.-00se.’ PHASE (DEC) *.....’../ EPP13920 4 2X,’F(t0Z)’.4X,’STTV,4X,’SPPM’,4X,’ STPM ’,4X,’SPTM...3751’, 38116370 a2 ’ S15U4’) ES8115380 ENDIF 18P15390 ENDIF ESPIS400 IFCIANG.GE. 1 )THEN ESP16410 XFCRF.LE.O.0)WRIT£(g,183)TH000,PHDOD,STTN,SPPM, STPM
Determination of the intervertebral disc space from CT images of the lumbar spine
NASA Astrophysics Data System (ADS)
Korez, Robert; Å tern, Darko; Likar, Boštjan; Pernuš, Franjo; Vrtovec, Tomaž
2014-03-01
Degenerative changes of the intervertebral disc are among the most common causes of low back pain, where for individuals with significant symptoms surgery may be needed. One of the interventions is the total disc replacement surgery, where the degenerated disc is replaced by an artificial implant. For designing implants with good bone contact and continuous force distribution, the morphology of the intervertebral disc space and vertebral body endplates is of considerable importance. In this study we propose a method for the determination of the intervertebral disc space from three-dimensional (3D) computed tomography (CT) images of the lumbar spine. The first step of the proposed method is the construction of a model of vertebral bodies in the lumbar spine. For this purpose, a chain of five elliptical cylinders is initialized in the 3D image and then deformed to resemble vertebral bodies by introducing 25 shape parameters. The parameters are obtained by aligning the chain to the vertebral bodies in the CT image according to image intensity and appearance information. The determination of the intervertebral disc space is finally achieved by finding the planes that fit the endplates of the obtained parametric 3D models, and placing points in the space between the planes of adjacent vertebrae that enable surface reconstruction of the intervertebral disc space. The morphometric analysis of images from 20 subjects yielded 11:3 +/- 2:6, 12:1 +/- 2:4, 12:8 +/- 2:0 and 12:9 +/- 2:7 cm3 in terms of L1-L2, L2-L3, L3-L4 and L4-L5 intervertebral disc space volume, respectively.
Fan, Wei; Guo, Li-Xin
2018-06-01
Few studies have evaluated the need for supplementary instrumentation after lumbar interbody fusion under the condition of whole body vibration (WBV) that is typically present in vehicles. This study aimed to determine the effect of posterior pedicle screw fixation on dynamic response of the whole lumbar spine to vertical WBV after transforaminal lumbar interbody fusion (TLIF). A previously validated nonlinear, osteoligamentous finite element (FE) model of the intact L1-sacrum human lumbar spine was modified to simulate single-level (L4-L5) TLIF without and with bilateral pedicle screw fixation (BPSF). Transit dynamic analysis was performed on the 2 developed models under a sinusoidal vertical vibration load of ±40 N and a compressive follower preload of 400 N. The resulting dynamic response results for the 2 models in terms of stresses and deformations were recorded and compared. When compared with no fixation, BPSF decreased dynamic responses of the spinal levels to the vertical vibration after TLIF. At the fused level (L4-L5), vibration amplitudes of the von-Mises stresses in L4 inferior endplate and L5 superior endplate decreased after BPSF by 48.0% and 46.4%, respectively. At other disc levels (L1-L2, L2-L3, L3-L4, and L5-S1), vibration amplitudes of the disc bulge, von-Mises stress in annulus ground substance and intradiscal pressure also produced 4.2%-9.0%, 2.3%-8.9%, and 3.4%-8.8% deceases, respectively, after BPSF. After TLIF, application of BPSF can be helpful in the prevention of spine injury during vertical WBV. Copyright © 2018 Elsevier Inc. All rights reserved.
Kim, Yeo Ju; Cha, Jang Gyu; Shin, Yoon Sang; Chaudhari, Akshay S; Suh, Young Ju; Hwan Yoon, Seung; Gold, Garry E
2018-05-01
The purpose of this study was to evaluate the feasibility of 3D ultrashort TE (UTE) MRI in depicting the cartilaginous endplate (CEP) and its abnormalities and to investigate the association between CEP abnormalities and disk degeneration on T2-weighted spin-echo (SE) MR images in cervical disks in vivo. Eight healthy volunteers and 70 patients were examined using 3-T MRI with the 3D UTE cones trajectory technique (TR/TE, 16.1/0.032, 6.6). In the volunteer study, quantitative and qualitative assessments of CEP depiction were conducted for the 3D UTE and T2-weighted SE imaging. In the patient study, CEP abnormalities were analyzed. Intersequence agreement between the images obtained with the first-echo 3D UTE sequence and the images created by subtracting the second-echo from the first-echo 3D UTE sequence (subtracted 3D UTE) and the intraobserver and interobserver agreements for 3D UTE overall were also tested. The CEP abnormalities on the 3D UTE images correlated with the Miyazaki grading of the T2-weighted SE images. In the volunteer study, the CEP was well visualized on 3D UTE images but not on T2-weighted SE images (p < 0.001). In the patient study, for evaluation of CEP abnormalities, intersequence agreements were substantial to almost perfect, intraobserver agreements were substantial to almost perfect, and interobserver agreements were moderate to substantial (p < 0.001). All of the CEP abnormalities correlated with the Miyazaki grade with statistical significance (p < 0.001). Three-dimensional UTE MRI feasibly depicts the CEP and CEP abnormalities, which may be associated with the severity of disk degeneration on T2-weighted SE MRI.
McClellan, Taylor; Allen, Brian C; Kappus, Matthew; Bhatti, Lubna; Dafalla, Randa A; Snyder, Laurie D; Bashir, Mustafa R
To determine interreader and intrareader repeatability and correlations among measurements of computerized tomography-based anthropomorphic measurements in patients with pulmonary fibrosis undergoing lung transplantation. This was an institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study of 23 randomly selected subjects (19 male and 4 female; median age = 69 years; range: 66-77 years) with idiopathic pulmonary fibrosis undergoing pulmonary transplantation, who had also undergone preoperative thoracoabdominal computerized tomography. Five readers of varying imaging experience independently performed the following cross-sectional area measurements at the inferior endplate of the L3 vertebral body: right and left psoas muscles, right and left paraspinal muscles, total abdominal musculature, and visceral and subcutaneous fat. The following measurements were obtained at the inferior endplate of T6: right and left paraspinal muscles with and without including the trapezius muscles and subcutaneous fat. Three readers repeated all measurements to assess intrareader repeatability. Intrareader repeatability was nearly perfect (interclass correlation coefficients = 0.99, P < 0.001). Interreader agreement was excellent across all 5 readers (interclass correlation coefficients: 0.71-0.99, P < 0.001). Coefficients of variance between measures ranged from 3.2%-6.8% for abdominal measurements, but were higher for thoracic measurements, up to 23.9%. Correlation between total paraspinal and total psoas muscle area was strong (r 2 = 0.67, P < 0.001). Thoracic and abdominal musculature had a weaker correlation (r 2 = 0.35-0.38, P < 0.001). Measures of thoracic and abdominal muscle and fat area are highly repeatable in patients with pulmonary fibrosis undergoing lung transplantation. Measures of muscle area are strongly correlated among abdominal locations, but inversely correlated between abdominal and thoracic locations. Copyright © 2017 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Sandover, J.
1998-08-01
The fatigue approach assumes that the vertebral end-plates are the weak link in the spine subjected to shock and vibration, and fail as a result of material fatigue. The theory assumes that end-plate damage leads to degeneration and pain in the lumbar spine. There is evidence for both the damage predicted and the fatigue mode of failure so that the approach may provide a basis for predictive methods for use in epidemiology and standards. An available data set from a variety of heavy vehicles in practical situations was used for predictions of spinal stress and fatigue life. Although there was some disparity between the predictive methods used, the more developed methods indicated fatigue lives that appeared reasonable, taking into account the vehicles tested and our knowledge of spinal degeneration. It is argued that the modelling and fatigue approaches combined offer a basis for estimating the effects of vibration and shock on health. Although the human variables are such that the approach, as yet, only offers rough estimates, it offers a good basis for understanding. The approach indicates that peak values are important and large peaks dominate risk. The method indicates that long term r.m.s. methods probably underestimate the risk of injury. The BS 6841Wband ISO 2631Wkweightings have shortcomings when used where peak values are important. A simple model may be more appropriate. The principle can be applied to continuous vibration as well as high acceleration events so that one method can be applied universally to continuous vibrations, high acceleration events and mixtures of these. An endurance limit can be hypothesised and, if this limit is sufficiently high, then the need for many measurements can be reduced.
Structure‐function relationships at the human spinal disc‐vertebra interface
Berg‐Johansen, Britta; Fields, Aaron J.; Liebenberg, Ellen C.; Li, Alfred
2017-01-01
ABSTRACT Damage at the intervertebral disc‐vertebra interface associates with back pain and disc herniation. However, the structural and biomechanical properties of the disc‐vertebra interface remain underexplored. We sought to measure mechanical properties and failure mechanisms, quantify architectural features, and assess structure‐function relationships at this vulnerable location. Vertebra‐disc‐vertebra specimens from human cadaver thoracic spines were scanned with micro‐computed tomography (μCT), surface speckle‐coated, and loaded to failure in uniaxial tension. Digital image correlation (DIC) was used to calculate local surface strains. Failure surfaces were scanned using scanning electron microscopy (SEM), and adjacent sagittal slices were analyzed with histology and SEM. Seventy‐one percent of specimens failed initially at the cartilage endplate‐bone interface of the inner annulus region. Histology and SEM both indicated a lack of structural integration between the cartilage endplate (CEP) and bone. The interface failure strength was increased in samples with higher trabecular bone volume fraction in the vertebral endplates. Furthermore, failure strength decreased with degeneration, and in discs with thicker CEPs. Our findings indicate that poor structural connectivity between the CEP and vertebra may explain the structural weakness at this region, and provide insight into structural features that may contribute to risk for disc‐vertebra interface injury. The disc‐vertebra interface is the site of failure in the majority of herniation injuries. Here we show new structure‐function relationships at this interface that may motivate the development of diagnostics, prevention strategies, and treatments to improve the prognosis for many low back pain patients with disc‐vertebra interface injuries. © 2017 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 36:192–201, 2018. PMID:28590060
Arnbak, Bodil; Jensen, Tue S; Egund, Niels; Zejden, Anna; Hørslev-Petersen, Kim; Manniche, Claus; Jurik, Anne G
2016-04-01
To estimate the prevalence of degenerative and spondyloarthritis (SpA)-related magnetic resonance imaging (MRI) findings in the spine and sacroiliac joints (SIJs) and analyse their association with gender and age in persistent low back pain (LBP) patients. Degenerative and SpA-related MRI findings in the whole spine and SIJs were evaluated in Spine Centre patients aged 18-40 years with LBP. Among the 1,037 patients, the prevalence of disc degeneration, disc contour changes and vertebral endplate signal (Modic) changes were 87 % (±SEM 1.1), 82 % (±1.2) and 48 % (±1.6). All degenerative spinal findings were most frequent in men and patients aged 30-40 years. Spinal SpA-related MRI findings were rare. In the SIJs, 28 % (±1.4) had at least one MRI finding, with bone marrow oedema being the most common (21 % (±1.3)). SIJ erosions were most prevalent in patients aged 18-29 years and bone marrow oedema in patients aged 30-40 years. SIJ sclerosis and fatty marrow deposition were most common in women. SIJ bone marrow oedema, sclerosis and erosions were most frequent in women indicating pregnancy-related LBP. The high prevalence of SIJ MRI findings associated with age, gender, and pregnancy-related LBP need further investigation of their clinical importance in LBP patients. • The location of vertebral endplate signal changes supports a mechanical aetiology. • Several sacroiliac joint findings were associated with female gender and pregnancy-related back pain. • Sacroiliac joint bone marrow oedema was frequent and age-associated, indicating a possible degenerative aetiology. • More knowledge of the clinical importance of sacroiliac joint MRI findings is needed.
Stokes, Ian A F; Laible, Jeffrey P; Gardner-Morse, Mack G; Costi, John J; Iatridis, James C
2011-01-01
Intervertebral disks support compressive forces because of their elastic stiffness as well as the fluid pressures resulting from poroelasticity and the osmotic (swelling) effects. Analytical methods can quantify the relative contributions, but only if correct material properties are used. To identify appropriate tissue properties, an experimental study and finite element analytical simulation of poroelastic and osmotic behavior of intervertebral disks were combined to refine published values of disk and endplate properties to optimize model fit to experimental data. Experimentally, nine human intervertebral disks with adjacent hemi-vertebrae were immersed sequentially in saline baths having concentrations of 0.015, 0.15, and 1.5 M and the loss of compressive force at constant height (force relaxation) was recorded over several hours after equilibration to a 300-N compressive force. Amplitude and time constant terms in exponential force-time curve-fits for experimental and finite element analytical simulations were compared. These experiments and finite element analyses provided data dependent on poroelastic and osmotic properties of the disk tissues. The sensitivities of the model to alterations in tissue material properties were used to obtain refined values of five key material parameters. The relaxation of the force in the three bath concentrations was exponential in form, expressed as mean compressive force loss of 48.7, 55.0, and 140 N, respectively, with time constants of 1.73, 2.78, and 3.40 h. This behavior was analytically well represented by a model having poroelastic and osmotic tissue properties with published tissue properties adjusted by multiplying factors between 0.55 and 2.6. Force relaxation and time constants from the analytical simulations were most sensitive to values of fixed charge density and endplate porosity.
Stokes, Ian A. F.; Laible, Jeffrey P.; Gardner-Morse, Mack G.; Costi, John J.; Iatridis, James C.
2011-01-01
Intervertebral disks support compressive forces because of their elastic stiffness as well as the fluid pressures resulting from poroelasticity and the osmotic (swelling) effects. Analytical methods can quantify the relative contributions, but only if correct material properties are used. To identify appropriate tissue properties, an experimental study and finite element analytical simulation of poroelastic and osmotic behavior of intervertebral disks were combined to refine published values of disk and endplate properties to optimize model fit to experimental data. Experimentally, nine human intervertebral disks with adjacent hemi-vertebrae were immersed sequentially in saline baths having concentrations of 0.015, 0.15, and 1.5 M and the loss of compressive force at constant height (force relaxation) was recorded over several hours after equilibration to a 300-N compressive force. Amplitude and time constant terms in exponential force–time curve-fits for experimental and finite element analytical simulations were compared. These experiments and finite element analyses provided data dependent on poroelastic and osmotic properties of the disk tissues. The sensitivities of the model to alterations in tissue material properties were used to obtain refined values of five key material parameters. The relaxation of the force in the three bath concentrations was exponential in form, expressed as mean compressive force loss of 48.7, 55.0, and 140 N, respectively, with time constants of 1.73, 2.78, and 3.40 h. This behavior was analytically well represented by a model having poroelastic and osmotic tissue properties with published tissue properties adjusted by multiplying factors between 0.55 and 2.6. Force relaxation and time constants from the analytical simulations were most sensitive to values of fixed charge density and endplate porosity. PMID:20711754
A Large Animal Model that Recapitulates the Spectrum of Human Intervertebral Disc Degeneration
Gullbrand, Sarah E.; Malhotra, Neil R.; Schaer, Thomas P.; Zawacki, Zosia; Martin, John T.; Bendigo, Justin R.; Milby, Andrew H.; Dodge, George R.; Vresilovic, Edward J.; Elliott, Dawn M.; Mauck, Robert L.; Smith, Lachlan J.
2016-01-01
Objective The objective of this study was to establish a large animal model that recapitulates the spectrum of intervertebral disc degeneration that occurs in humans and which is suitable for pre-clinical evaluation of a wide range of experimental therapeutics. Design Degeneration was induced in the lumbar intervertebral discs of large frame goats by either intradiscal injection of chondroitinase ABC (ChABC) over a range of dosages (0.1U, 1U or 5U) or subtotal nucleotomy. Radiographs were used to assess disc height changes over 12 weeks. Degenerative changes to the discs and endplates were assessed via magnetic resonance imaging (MRI), semi-quantitative histological grading, micro-computed tomography (µCT), and measurement of disc biomechanical properties. Results Degenerative changes were observed for all interventions that ranged from mild (0.1U ChABC) to moderate (1U ChABC and nucleotomy) to severe (5U ChABC). All groups showed progressive reductions in disc height over 12 weeks. Histological scores were significantly increased in the 1U and 5U ChABC groups. Reductions in T2 and T1ρ, and increased Pfirrmann grade were observed on MRI. Resorption and remodeling of the cortical boney endplate adjacent to ChABC injected discs also occurred. Spine segment range of motion was greater and compressive modulus was lower in 1U ChABC and nucleotomy discs compared to intact. Conclusions A large animal model of disc degeneration was established that recapitulates the spectrum of structural, compositional and biomechanical features of human disc degeneration. This model may serve as a robust platform for evaluating the efficacy of therapeutics targeted towards varying degrees of disc degeneration. PMID:27568573
Establishment of a New Zealand rabbit model of spinal tuberculosis.
Geng, Guangqi; Wang, Qian; Shi, Jiandang; Yan, Junfa; Niu, Ningkui; Wang, Zili
2015-04-01
This was an experimental study. To investigate and evaluate the experimental method of establishing a New Zealand rabbit model of spinal tuberculosis. Establishing animal models of tuberculosis is critical to the experimental and clinical study of tuberculosis, especially spinal tuberculosis. However, the rapid spread of Mycobacterium tuberculosis and subsequent high mortality thwarted their effort. Since then, no animal models have been established of spinal tuberculosis. Forty-two New Zealand rabbits were randomly divided into experimental (n=20), control (n=20), and blank groups (n=2). Experimental animals were sensitized by complete Freund's adjuvant. A hole drilled under the upper endplate of the L4 vertebral body was filled with a gelfoam sponge infused with 0.1 mL H37Rv standard M. tuberculosis suspension (in controls, culture medium, and saline). Blank animals received no treatment. Survival 8 weeks after surgery was 89.5%, 94.7%, and 100% in experimental, control, and blank groups, respectively. The model was successfully established in all surviving experimental rabbits. In experimental animals, vertebral body destruction at 4 weeks was 50% by x-ray; 83.3% by computed tomography reconstruction and magnetic resonance imaging; at 8 weeks, 58.8% by x-ray and 100% by computed tomograph reconstruction and magnetic resonance imaging. At 8 weeks, experimental animals developed vertebral destruction, granulation, and necrosis and 17.6% had psoas abscess. Histopathology revealed numerous lymphocytes and epithelioid cells, trabecular bone fracture, and coagulative necrosis in the vertebrae of experimental animals; bacterium culture was 52.9% positive. Control and blank animals showed no such changes. A New Zealand rabbit of spinal tuberculosis model can be successfully established by drilling a hole in the upper endplate of the vertebral body, filling with gelfoam sponge infused with H37Rv standard M. tuberculosis suspension after sensitization by complete Freund's adjuvant.
Akbar, Saleem; Dhar, Shabir A.
2008-01-01
To assess the efficacy and feasibility of vertebroplasty and posterior short-segment pedicle screw fixation for the treatment of traumatic lumbar burst fractures. Short-segment pedicle screw instrumentation is a well described technique to reduce and stabilize thoracic and lumbar spine fractures. It is relatively a easy procedure but can only indirectly reduce a fractured vertebral body, and the means of augmenting the anterior column are limited. Hardware failure and a loss of reduction are recognized complications caused by insufficient anterior column support. Patients with traumatic lumbar burst fractures without neurologic deficits were included. After a short segment posterior reduction and fixation, bilateral transpedicular reduction of the endplate was performed using a balloon, and polymethyl methacrylate cement was injected. Pre-operative and post-operative central and anterior heights were assessed with radiographs and MRI. Sixteen patients underwent this procedure, and a substantial reduction of the endplates could be achieved with the technique. All patients recovered uneventfully, and the neurologic examination revealed no deficits. The post-operative radiographs and magnetic resonance images demonstrated a good fracture reduction and filling of the bone defect without unwarranted bone displacement. The central and anterior height of the vertebral body could be restored to 72 and 82% of the estimated intact height, respectively. Complications were cement leakage in three cases without clinical implications and one superficial wound infection. Posterior short-segment pedicle fixation in conjunction with balloon vertebroplasty seems to be a feasible option in the management of lumbar burst fractures, thereby addressing all the three columns through a single approach. Although cement leakage occurred but had no clinical consequences or neurological deficit. PMID:18193300
Hydrostatic pressure modifies the action of octanol and atropine on frog endplate conductance.
Ashford, M. L.; Macdonald, A. G.; Wann, K. T.
1984-01-01
The effects of octanol, ethanol and atropine were examined on the time course of decay (tau D) of miniature endplate currents (m.e.p.cs) in the frog neuromuscular junction at normal and high pressure. Octanol (25-100 microM) decreased reversibly the tau D of m.e.p.cs in a dose-dependent manner, 100 microM reducing tau D to 0.39 of the control value. Higher concentrations (200-500 microM) additionally depressed the amplitude of m.e.p.cs. Hydrostatic pressure (3.19 and 5.25 MPa) reduced the tau D of octanol (25-100 microM)-shortened m.e.p.cs. Thus 3.19 MPa and 5.25 MPa reduced the tau D in the presence of 100 microM octanol to 0.75 and 0.78 of the octanol treated values. This effect was not completely reversed on decompression. The m.e.p.c. amplitude is reversibly decreased by pressure in the presence of octanol. Hydrostatic pressure (3.19-15.55 MPa) did not modify the effect of ethanol on tau D. At 10.40 and 15.55 MPa the tau D was increased equally in the absence or presence of ethanol. Atropine (60 microM) reduced the tau D and amplitude of m.e.p.cs to 0.33 and 0.63 of the control values. These effects were completely reversible. Hydrostatic pressure (3.19 and 5.25 MPa) reduced the tau D of atropine-shortened m.e.p.cs to 0.82 and 0.77 of the atropine-treated values respectively. This effect was not completely reversed on decompression. Hydrostatic pressure also reversibly depressed the amplitude of atropine-treated m.e.p.cs. The implications of these drug-hydrostatic pressure interactions are discussed. PMID:6333262
Milani, Giovana Barbosa; Filho, A’Dayr Natal; João, Sílvia Maria Amado
2008-01-01
INTRODUCTION Gynoid lipodystrophy (cellulite) has been cited as a common dermatological alteration. It occurs mainly in adult women and tends to gather around the thighs and buttocks. Its presence and severity have been related to many factors, including biotype, age, sex, circulatory changes, and, as some authors have suggested, mechanical alterations such as lumbar hyperlordosis. OBJECTIVE To correlate the degree of cellulite with the angle of lumbar lordosis in asymptomatic women. METHODS Fifty volunteers were evaluated by digital photos, palpation, and thermograph. The degree of cellulite was classified on a scale of 1–4. Analyses were performed on the superior, inferior, right and left buttocks (SRB, IRB, SLB, ILB), and the superior right and left thighs (SRT, SLT). The volunteers underwent a lateral-view X-ray, and the angle of lumbar lordosis was measured using Cobb’s method (inferior endplate of T12 and the superior endplate of S). The data were statistically analyzed using ANOVA and Spearman’s correlation. A significance level of 5% was adopted. RESULTS Volunteers had a mean age of 26.1 ± 4.4 years and a mean body mass index of 20.7 ± 1.9 kg/m2. There was no significant difference in lumbar lordosis angle between those with cellulite classes 2 and 3 (p ≥ 0.297). There was also no correlation between lumbar lordosis angle and the degree of cellulite (p ≥ 0.085 and r ≥ 0.246). CONCLUSIONS The analysis suggests that there is no correlation between the degree of cellulite and the angle of lumbar lordosis as measured using Cobb’s method. PMID:18719762
Ward, Patricia J; Jones, Laura N; Mulligan, Amanda; Goolsby, William; Wilhelm, Jennifer C; English, Arthur W
2016-01-01
Peripheral nerve injuries are common, and functional recovery is very poor. Beyond surgical repair of the nerve, there are currently no treatment options for these patients. In experimental models of nerve injury, interventions (such as exercise and electrical stimulation) that increase neuronal activity of the injured neurons effectively enhance axon regeneration. Here, we utilized optogenetics to determine whether increased activity alone is sufficient to promote motor axon regeneration. In thy-1-ChR2/YFP transgenic mice in which a subset of motoneurons express the light-sensitive cation channel, channelrhodopsin (ChR2), we activated axons in the sciatic nerve using blue light immediately prior to transection and surgical repair of the sciatic nerve. At four weeks post-injury, direct muscle EMG responses evoked with both optical and electrical stimuli as well as the ratio of these optical/electrical evoked EMG responses were significantly greater in mice that received optical treatment. Thus, significantly more ChR2+ axons successfully re-innervated the gastrocnemius muscle in mice that received optical treatment. Sections of the gastrocnemius muscles were reacted with antibodies to Synaptic Vesicle Protein 2 (SV2) to quantify the number of re-occupied motor endplates. The number of SV2+ endplates was greater in mice that received optical treatment. The number of retrogradely-labeled motoneurons following intramuscular injection of cholera toxin subunit B (conjugated to Alexa Fluor 555) was greater in mice that received optical treatment. Thus, the acute (1 hour), one-time optical treatment resulted in robust, long-lasting effects compared to untreated animals as well as untreated axons (ChR2-). We conclude that neuronal activation is sufficient to promote motor axon regeneration, and this regenerative effect is specific to the activated neurons.
In vivo Loads in the Lumbar L3-4 Disc during a Weight Lifting Extension
Wang, Shaobai; Park, Won Man; Kim, Yoon Hyuk; Cha, Thomas; Wood, Kirkham; Li, Guoan
2014-01-01
Background Knowledge of in vivo human lumbar loading is critical for understanding the lumbar function and for improving surgical treatments of lumbar pathology. Although numerous experimental measurements and computational simulations have been reported, non-invasive determination of in vivo spinal disc loads is still a challenge in biomedical engineering. The object of the study is to investigate the in vivo human lumbar disc loads using a subject-specific and kinematic driven finite element approach. Methods Three dimensional (3D) lumbar spine models of three living subjects were created using MR images. A 3D finite element model of the L3-4 disc, including the annulus fibrosus and nucleus pulposus, was built for each subject. The endplate kinematics of the L3-4 segment of each subject during a dynamic weight lifting extension was determined using a dual fluoroscopic imaging technique. The endplate kinematics was used as displacement boundary conditions of the subject specific finite element model of the L3-4 disc to calculate the in-vivo disc forces and moments during the weight lifting activity. Findings During the weight lifting extension, the L3-4 disc experienced maximum shear load of about 230 N or 0.34 bodyweight at the flexion position and maximum compressive load of 1500 N or 2.28 bodyweight at the upright position. The disc experienced a primary flexion-extension moment during the motion which reached a maximum of 4.2 Nm at upright position with stretched arms holding the weight. Interpretation This study provided quantitative data on in vivo disc loading that could help understand intrinsic biomechanics of the spine and improve surgical treatment of pathological discs using fusion or arthroplasty techniques. PMID:24345591
2011-01-01
Active myofascial trigger points are one of the major peripheral pain generators for regional and generalized musculoskeletal pain conditions. Myofascial trigger points are also the targets for acupuncture and/or dry needling therapies. Recent evidence in the understanding of the pathophysiology of myofascial trigger points supports The Integrated Hypothesis for the trigger point formation; however unanswered questions remain. Current evidence shows that spontaneous electrical activity at myofascial trigger point originates from the extrafusal motor endplate. The spontaneous electrical activity represents focal muscle fiber contraction and/or muscle cramp potentials depending on trigger point sensitivity. Local pain and tenderness at myofascial trigger points are largely due to nociceptor sensitization with a lesser contribution from non-nociceptor sensitization. Nociceptor and non-nociceptor sensitization at myofascial trigger points may be part of the process of muscle ischemia associated with sustained focal muscle contraction and/or muscle cramps. Referred pain is dependent on the sensitivity of myofascial trigger points. Active myofascial trigger points may play an important role in the transition from localized pain to generalized pain conditions via the enhanced central sensitization, decreased descending inhibition and dysfunctional motor control strategy. PMID:21439050
The Effect of Electrical Stimulation in Improving Muscle Tone (Clinical)
NASA Astrophysics Data System (ADS)
Azman, M. F.; Azman, A. W.
2017-11-01
Electrical stimulation (ES) and also known as neuromuscular electrical stimulation (NMES) and transcutaneous electrical stimulation (TES) involves the use of electrical current to stimulate the nerves or nerve endings that innervate muscle beneath the skin. Electrical stimulation may be applied superficially on the skin (transcutaneously) or directly into a muscle or muscles (intramuscularly) for the primary purpose of enhancing muscle function. The basic theoretical premise is that if the peripheral nerve can be stimulated, the resulting excitation impulse will be transmitted along the nerve to the motor endplates in the muscle, producing a muscle contraction. In this work, the effect of mere electrical stimulation to the muscle bulk and strength are tested. This paper explains how electrical stimulation can affect the muscle bulk, muscle size, muscle tone, muscle atrophy and muscle strength. The experiment and data collection are performed on 5 subjects and the results obtained are analyzed. This research aims to understand the full potential of electrical stimulation and identifying its possible benefits or disadvantages to the muscle properties. The results indicated that electrical stimulation alone able to improve muscle properties but with certain limits and precautions which might be useful in rehabilitation programme.
Measuring the environmental awareness of young farmers
NASA Astrophysics Data System (ADS)
Kountios, G.; Ragkos, A.; Padadavid, G.; Hadjimitsis, D.
2017-09-01
Young farmers in Europe, especially the beneficiaries of Common Agricultural Policy (CAP) funding schemes, are considered as the ones who could ensure the sustainability of the European Model of Agriculture. Economic efficiency and competitiveness, aversion of depopulation of rural areas and environmental protection constitute some of the key objectives of the CAP and young farmers are expected to play a role to all of them. This study proposes a way of measuring the potential of young farmers to contribute to the latter objectives of the CAP by estimating their environmental attitudes. Data from a questionnaire survey of 492 Greek young farmers were used to design a latent construct measuring their environmental attitudes. The latent construct was designed by means of an Explanatory Factor Analysis (EFA) using the responses to a set of 12 Likert-scale items. The results the EFA yielded a latent construct with three factors related to "Environmental pollution and policies (EPP)", "Environmental factors and food quality (EFF)" and "Farming practices and the environment". These results were validated through a CFA where 8 items in total were categorized in the three factors (latent variables). The utilization of the latent construct for the effective implementation of CAP measures could ameliorate the relationships of agriculture and environment in general.
Nuclear structure functions at a future electron-ion collider
Aschenauer, E. C.; Fazio, S.; Lamont, M. A. C.; ...
2017-12-07
The quantitative knowledge of heavy nuclei's partonic structure is currently limited to rather large values of momentum fraction x { robust experimental constraints below x ~ 10 -2 at low resolution scale Q 2 are particularly scarce. This is in sharp contrast to the free proton's structure which has been probed in deep inelastic scattering (DIS) measurements down to x ~ 10 -5 at perturbative resolution scales. The construction of an Electron-Ion Collider (EIC) with a possibility to operate with a wide variety of nuclei, will allow one to explore the low-x region in much greater detail. In the presentmore » paper we simulate the extraction of the nuclear structure functions from measurements of inclusive and charm reduced cross sections at an EIC. The potential constraints are studied by analyzing simulated data directly in a next-to-leading order global fit of nuclear parton distribution functions based on the recent EPPS16 analysis. A special emphasis is placed on studying the impact an EIC would have on extracting the nuclear gluon PDF, the partonic component most prone to non-linear e ects at low Q 2. In comparison to the current knowledge, we find that the gluon PDF can be measured at an EIC with significantly reduced uncertainties.« less
Nuclear structure functions at a future electron-ion collider
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aschenauer, E. C.; Fazio, S.; Lamont, M. A. C.
The quantitative knowledge of heavy nuclei's partonic structure is currently limited to rather large values of momentum fraction x { robust experimental constraints below x ~ 10 -2 at low resolution scale Q 2 are particularly scarce. This is in sharp contrast to the free proton's structure which has been probed in deep inelastic scattering (DIS) measurements down to x ~ 10 -5 at perturbative resolution scales. The construction of an Electron-Ion Collider (EIC) with a possibility to operate with a wide variety of nuclei, will allow one to explore the low-x region in much greater detail. In the presentmore » paper we simulate the extraction of the nuclear structure functions from measurements of inclusive and charm reduced cross sections at an EIC. The potential constraints are studied by analyzing simulated data directly in a next-to-leading order global fit of nuclear parton distribution functions based on the recent EPPS16 analysis. A special emphasis is placed on studying the impact an EIC would have on extracting the nuclear gluon PDF, the partonic component most prone to non-linear e ects at low Q 2. In comparison to the current knowledge, we find that the gluon PDF can be measured at an EIC with significantly reduced uncertainties.« less
Report on FY15 alloy 617 code rules development
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sham, Sam; Jetter, Robert I; Hollinger, Greg
2015-09-01
Due to its strength at very high temperatures, up to 950°C (1742°F), Alloy 617 is the reference construction material for structural components that operate at or near the outlet temperature of the very high temperature gas-cooled reactors. However, the current rules in the ASME Section III, Division 5 Subsection HB, Subpart B for the evaluation of strain limits and creep-fatigue damage using simplified methods based on elastic analysis have been deemed inappropriate for Alloy 617 at temperatures above 650°C (1200°F) (Corum and Brass, Proceedings of ASME 1991 Pressure Vessels and Piping Conference, PVP-Vol. 215, p.147, ASME, NY, 1991). The rationalemore » for this exclusion is that at higher temperatures it is not feasible to decouple plasticity and creep, which is the basis for the current simplified rules. This temperature, 650°C (1200°F), is well below the temperature range of interest for this material for the high temperature gas-cooled reactors and the very high temperature gas-cooled reactors. The only current alternative is, thus, a full inelastic analysis requiring sophisticated material models that have not yet been formulated and verified. To address these issues, proposed code rules have been developed which are based on the use of elastic-perfectly plastic (EPP) analysis methods applicable to very high temperatures. The proposed rules for strain limits and creep-fatigue evaluation were initially documented in the technical literature (Carter, Jetter and Sham, Proceedings of ASME 2012 Pressure Vessels and Piping Conference, papers PVP 2012 28082 and PVP 2012 28083, ASME, NY, 2012), and have been recently revised to incorporate comments and simplify their application. Background documents have been developed for these two code cases to support the ASME Code committee approval process. These background documents for the EPP strain limits and creep-fatigue code cases are documented in this report.« less
NASA Astrophysics Data System (ADS)
Drożdż, Stanisław; Kwapień, Jarosław; Oświȩcimka, Paweł; Rak, Rafał
2010-10-01
We present a systematic study of various statistical characteristics of high-frequency returns from the foreign exchange market. This study is based on six exchange rates forming two triangles: EUR-GBP-USD and GBP-CHF-JPY. It is shown that the exchange rate return fluctuations for all of the pairs considered are well described by the non-extensive statistics in terms of q-Gaussians. There exist some small quantitative variations in the non-extensivity q-parameter values for different exchange rates (which depend also on the time scales studied), and this can be related to the importance of a given exchange rate in the world's currency trade. Temporal correlations organize the series of returns such that they develop the multifractal characteristics for all of the exchange rates, with a varying degree of symmetry of the singularity spectrum f(α), however. The most symmetric spectrum is identified for the GBP/USD. We also form time series of triangular residual returns and find that the distributions of their fluctuations develop disproportionately heavier tails as compared to small fluctuations, which excludes description in terms of q-Gaussians. The multifractal characteristics of these residual returns reveal such anomalous properties as negative singularity exponents and even negative singularity spectra. Such anomalous multifractal measures have so far been considered in the literature in connection with diffusion-limited aggregation and with turbulence. Studying the cross-correlations among different exchange rates, we found that market inefficiency on short time scales leads to the occurrence of the Epps effect on much longer time scales, but comparable to the ones for the stock market. Although the currency market is much more liquid than the stock markets and has a much greater transaction frequency, the building up of correlations takes up to several hours—a duration that does not differ much from what is observed in the stock markets. This may suggest that non-synchronicity of transactions is not the unique source of the observed effect.
Shan, Zhi; Zhang, Xuyang; Li, Shengyun; Yu, Tianming; Mamuti, Maiwulanjiang; Zhao, Fengdong
2017-03-15
Modic changes (inflammatory-like changes visible on magnetic resonance imaging [MRI] scans of a vertebral end plate) are common and are associated with low back pain, but their origin is unclear. To our knowledge, there have been no previous in vivo animal models of Modic changes. We hypothesized that Modic changes may be related to Propionibacterium acnes. Ten New Zealand White rabbits were injected percutaneously with 1 mL of P. acnes (1.6 × 10 colony forming units/mL) into the subchondral bone superior to the L4-L5 and L5-L6 discs; 10 other control rabbits received sham injections at L4-L5 and 1 mL of normal saline solution (vehicle) at L5-L6. The subchondral bone superior to L3-L4 discs was untreated (blank). Development of Modic changes was investigated with MRI studies before the operation and at 2 weeks and 1, 2, 3, and 6 months postoperatively. Following sacrifice of the rabbits, histological analysis and microcomputed tomography (micro-CT) were performed, and blood samples were analyzed. Cytokine expression in end-plate tissues was quantified using real-time polymerase chain reaction (PCR). The group that received P. acnes showed significantly increased T1-weighted signal intensity at 6 months (mean and standard deviation, 3.43 ± 0.41 [range, 2.42 to 4.44] compared with 2.43 ± 0.66 [range, 1.98 to 2.87] before the injection) and higher T2-weighted signal intensity at 6 months. Positive culture results were obtained from 9 of 20 samples injected with P. acnes. Specimens with positive cultures had a higher prevalence of Modic changes (4 of 9 samples positive for P. acnes compared with 3 of 11 samples negative for P. acnes). Real-time PCR showed significantly increased expression of tumor necrosis factor-α, interleukin-1β, and interferon-γ following injection of P. acnes, but no changes were seen on histological analysis, micro-CT, or blood analysis. P. acnes can survive within the end-plate region and can initiate mild inflammatory-like responses from host cells, leading to signal intensity changes in MRI scans, which potentially resemble Modic changes. Disc degeneration and low back pain are associated with Modic changes. Our results indicate that Modic changes can be associated with P. acnes in the conjunction area of the disc and subchondral bone. These results may be useful for understanding the underlying mechanisms of Modic changes and related pain.
Complicating autoimmune diseases in myasthenia gravis: a review
Nacu, Aliona; Andersen, Jintana Bunpan; Lisnic, Vitalie; Owe, Jone Furlund; Gilhus, Nils Erik
2015-01-01
Abstract Myasthenia gravis (MG) is a rare autoimmune disease of skeletal muscle endplates. MG subgroup is relevant for comorbidity, but usually not accounted for. MG patients have an increased risk for complicating autoimmune diseases, most commonly autoimmune thyroid disease, systemic lupus erythematosus and rheumatoid arthritis. In this review, we present concomitant autoimmune disorders associated with the different MG subgroups, and show how this influences treatment and prognosis. Concomitant MG should always be considered in patients with an autoimmune disorder and developing new neuromuscular weakness, fatigue or respiratory failure. When a second autoimmune disorder is suspected, MG should be included as a differential diagnosis. PMID:25915571
NASA Technical Reports Server (NTRS)
Garland, D. B.
1980-01-01
Modifications were made to the model to improve longitudinal acceleration capability during transition from hovering to wing borne flight. A rearward deflection of the fuselage augmentor thrust vector is shown to be beneficial in this regard. Other agmentor modifications were tested, notably the removal of both endplates, which improved acceleration performance at the higher transition speeds. The model tests again demonstrated minimal interference of the fuselage augmentor on aerodynamic lift. A flapped canard surface also shows negligible influence on the performance of the wing and of the fuselage augmentor.
Long-term effects of vertebroplasty: adjacent vertebral fractures.
Baroud, Gamal; Vant, Christianne; Wilcox, Ruth
2006-01-01
In today's aging population, osteoporosis-related fractures are an ever-growing concern. Vertebroplasty, a promising yet cost-effective treatment for vertebral compression fractures, has an increasing role. The first vertebroplasty procedures were reported by Deramond and Galibert in France in 1987, and international interest grew with continued development of clinical techniques and augmentation materials in Europe and the United States. Initial publications and presentations at peer review meetings demonstrated 60-90% success rates in providing immediate and significant pain relief. The objective of this review is to assemble experimental and computational biomechanical research whose goal is determining and preventing the negative long-term effects ofvertebroplasty, with a specific focus on adjacent vertebral fractures. Biomechanical studies using isolated cancellous bone cylinders have shown that osteoporotic cancellous bone samples augmented by the rigid bone cement were at least 12 times stiffer and 35 times stronger than the untreated osteoporotic cancellous bone samples. The biomechanical efficacy of the procedure to repair the fractured vertebrae and prevent further collapse is determined using single-vertebra models. The strength or load-bearing capacity of a single vertebra is significantly increased following augmentation when compared to the intact strength. However, there is no dear result regarding the overall stiffness of the single vertebra, with studies reporting contradictorily that the stiffness increases, decreases, or does not significantly alter following augmentation. The effects of vertebroplasty on adjacent structures are studied via multisegment models, whose results plainly oppose the findings of the single-vertebra and intravertebral models. Here, augmentation was shown to decrease the overall segment strength by 19% when compared to the matched controls. As well, there is a significant increase in disc pressure compared to the pre-augmentation measurements. This translates to a high hydrostatic pressure adjacent to the augmented vertebra, representing the first evidence of increased loading. Computational finite element (FE) models have found that the rigid cement augmentation results in an increase in loading in the structures adjacent to the augmented vertebra. The mechanism of the increase of the loading is predicted to be the pillar effect of the rigid cement. The cement inhibits the normal endplate bulge into the augmented vertebra and thus pressurizes the adjacent disc, which subsequently increases the loading of the untreated vertebra. The mechanism for adjacent vertebral fractures is still unclear, but from experimental and computational studies, it appears that the change in mechanical loading following augmentation is responsible. The pillar effect of injected cement is hypothesized to decrease the endplate bulge in the augmented vertebra causing an increase in adjacent disc pressure that is communicated to the adjacent vertebra. To confirm the viability of the pillar effect as the responsible mechanism, endplate bulge and disc pressure should be directly measured before and after augmentation. Future studies should be concerned with quantifying the current and ideal mechanical response of the spine and subsequently developing cements that can achieve this optimum response.
Smith, Lachlan J; Martin, John T; Szczesny, Spencer E; Ponder, Katherine P; Haskins, Mark E; Elliott, Dawn M
2010-01-01
Mucopolysaccharidosis VII (MPS VII) is a lysosomal storage disorder characterized by a deficiency in β-glucuronidase activity, leading to systemic accumulation of poorly degraded glycosaminoglycans (GAG). Along with other morbidities, MPS VII is associated with paediatric spinal deformity. The objective of this study was to examine potential associations between abnormal lumbar spine matrix structure and composition in MPS VII, and spine segment and tissue-level mechanical properties, using a naturally occurring canine model with a similar clinical phenotype to the human form of the disorder. Segments from juvenile MPS VII and unaffected dogs were allocated to: radiography, gross morphology, histology, biochemistry, and mechanical testing. MPS VII spines had radiolucent lesions in the vertebral body epiphyses. Histologically, this corresponded to a GAG-rich cartilaginous region in place of bone, and elevated GAG staining was seen in the annulus fibrosus. Biochemically, MPS VII samples had elevated GAG in the outer annulus fibrosus and epiphyses, low calcium in the epiphyses, and high water content in all regions except the nucleus pulposus. MPS VII spine segments had higher range of motion and lower stiffness than controls. Endplate indentation stiffness and failure loads were significantly lower in MPS VII samples, while annulus fibrosus tensile mechanical properties were normal. Vertebral body lesions in MPS VII spines suggest a failure to convert cartilage to bone during development. Low stiffness in these regions likely contributes to mechanical weakness in motion segments and is a potential factor in the progression of spinal deformity. PMID:19918911
Foxa1 and Foxa2 are required for formation of the intervertebral discs.
Maier, Jennifer A; Lo, YinTing; Harfe, Brian D
2013-01-01
The intervertebral disc (IVD) is composed of 3 main structures, the collagenous annulus fibrosus (AF), which surrounds the gel-like nucleus pulposus (NP), and hyaline cartilage endplates, which are attached to the vertebral bodies. An IVD is located between each vertebral body. Degeneration of the IVD is thought to be a major cause of back pain, a potentially chronic condition for which there exist few effective treatments. The NP forms from the embryonic notochord. Foxa1 and Foxa2, transcription factors in the forkhead box family, are expressed early during notochord development. However, embryonic lethality and the absence of the notochord in Foxa2 null mice have precluded the study of potential roles these genes may play during IVD formation. Using a conditional Foxa2 allele in conjunction with a tamoxifen-inducible Cre allele (ShhcreER(T2)), we removed Foxa2 from the notochord of E7.5 mice null for Foxa1. Foxa1(-/-);Foxa2(c/c);ShhcreER(T2) double mutant animals had a severely deformed nucleus pulposus, an increase in cell death in the tail, decreased hedgehog signaling, defects in the notochord sheath, and aberrant dorsal-ventral patterning of the neural tube. Embryos lacking only Foxa1 or Foxa2 from the notochord were indistinguishable from control animals, demonstrating a functional redundancy for these genes in IVD formation. In addition, we provide in vivo genetic evidence that Foxa genes are required for activation of Shh in the notochord.
Foxa1 and Foxa2 Are Required for Formation of the Intervertebral Discs
Maier, Jennifer A.; Lo, YinTing; Harfe, Brian D.
2013-01-01
The intervertebral disc (IVD) is composed of 3 main structures, the collagenous annulus fibrosus (AF), which surrounds the gel-like nucleus pulposus (NP), and hyaline cartilage endplates, which are attached to the vertebral bodies. An IVD is located between each vertebral body. Degeneration of the IVD is thought to be a major cause of back pain, a potentially chronic condition for which there exist few effective treatments. The NP forms from the embryonic notochord. Foxa1 and Foxa2, transcription factors in the forkhead box family, are expressed early during notochord development. However, embryonic lethality and the absence of the notochord in Foxa2 null mice have precluded the study of potential roles these genes may play during IVD formation. Using a conditional Foxa2 allele in conjunction with a tamoxifen-inducible Cre allele (ShhcreERT2), we removed Foxa2 from the notochord of E7.5 mice null for Foxa1. Foxa1−/−;Foxa2c/c;ShhcreERT2 double mutant animals had a severely deformed nucleus pulposus, an increase in cell death in the tail, decreased hedgehog signaling, defects in the notochord sheath, and aberrant dorsal-ventral patterning of the neural tube. Embryos lacking only Foxa1 or Foxa2 from the notochord were indistinguishable from control animals, demonstrating a functional redundancy for these genes in IVD formation. In addition, we provide in vivo genetic evidence that Foxa genes are required for activation of Shh in the notochord. PMID:23383217
Brophy, Carl M; Hoh, Daniel J
2018-06-01
Cervical disc arthroplasty (CDA) has received widespread attention as an alternative to anterior fusion due to its similar neurological and functional improvement, with the advantage of preservation of segmental motion. As CDA becomes more widely implemented, the potential for unexpected device-related adverse events may be identified. The authors report on a 48-year-old man who presented with progressive neurological deficits 3 years after 2-level CDA was performed. Imaging demonstrated periprosthetic osteolysis of the vertebral endplates at the CDA levels, with a heterogeneously enhancing ventral epidural mass compressing the spinal cord. Diagnostic workup for infectious and neoplastic processes was negative. The presumptive diagnosis was an inflammatory pannus formation secondary to abnormal motion at the CDA levels. Posterior cervical decompression and instrumented fusion was performed without removal of the arthroplasty devices or the ventral epidural mass. Postoperative imaging at 2 months demonstrated complete resolution of the compressive pannus, with associated improvement in clinical symptoms. Follow-up MRI at > 6 months showed no recurrence of the pannus. At 1 year postoperatively, CT scanning revealed improvement in periprosthetic osteolysis. Inflammatory pannus formation may be an unexpected complication of abnormal segmental motion after CDA. This rare etiology of an epidural mass associated with an arthroplasty device should be considered, in addition to workup for other potential infectious or neoplastic mass lesions. In symptomatic individuals, compressive pannus lesions can be effectively treated with fusion across the involved segment without removal of the device.
M6-C artificial disc placement.
Coric, Domagoj; Parish, John; Boltes, Margaret O
2017-01-01
There has been a steady evolution of cervical total disc replacement (TDR) devices over the last decade resulting in surgical technique that closely mimics anterior cervical discectomy and fusion as well as disc design that emphasizes quality of motion. The M6-C TDR device is a modern-generation artificial disc composed of titanium endplates with tri-keel fixation as well as a polyethylene weave with a polyurethane core. Although not yet approved by the FDA, M6-C has finished a pilot and pivotal US Investigational Device Exemption (IDE) study. The authors present the surgical technique for implantation of a 2-level M6-C cervical TDR device. The video can be found here: https://youtu.be/rFEAqINLRCo .
FOREWORD: Corfu Summer Institute on Elementary Particle Physics (CORFU2005)
NASA Astrophysics Data System (ADS)
Anagnostopoulos, Konstantinos; Antoniadis, Ignatios; Fanourakis, George; Kehagias, Alexandros; Savoy-Navarro, Aurore; Wess, Julius; Zoupanos, George
2006-12-01
These are the Proceedings of the Corfu Summer Institute on Elementary Particle Physics (CORFU2005) (http://corfu2005.physics.uoi.gr), which took place in Corfu, Greece from 4 - 26 September 2005. The Corfu Summer Institute has a very long, interesting and successful history, some elements of which can be found in http://www.corfu-summer-institute.gr. In short, the Corfu Meeting started as a Summer School on Elementary Particle Physics (EPP) mostly for Greek graduate students in 1982 and has developed into a leading international Summer Institute in the field of EPP, both experimental and theoretical, providing in addition a very rich outreach programme to teachers and school students. The CORFU2005 Summer Institute on EPP, although based on the general format that has been developed and established in the Corfu Meetings during previous years, is characterized by the fact that it was a full realization of a new idea, which started experimentally in the previous two Corfu Meetings. The successful new ingredient was that three European Marie Curie Research Training Networks decided to hold their Workshops in Corfu during September 2005 and they managed to coordinate the educational part of their meetings to a huge Summer School called `The 8th Hellenic School on Elementary Particle Physics' (4 - 11 September). The European Networks which joined forces to materialize this project and the corresponding dates of their own Workshops are:
Suppression of CHRN endocytosis by carbonic anhydrase CAR3 in the pathogenesis of myasthenia gravis
Du, Ailian; Huang, Shiqian; Zhao, Xiaonan; Feng, Kuan; Zhang, Shuangyan; Huang, Jiefang; Miao, Xiang; Baggi, Fulvio; Ostrom, Rennolds S.; Zhang, Yanyun; Chen, Xiangjun; Xu, Congfeng
2017-01-01
ABSTRACT Myasthenia gravis is an autoimmune disorder of the neuromuscular junction manifested as fatigable muscle weakness, which is typically caused by pathogenic autoantibodies against postsynaptic CHRN/AChR (cholinergic receptor nicotinic) in the endplate of skeletal muscle. Our previous studies have identified CA3 (carbonic anhydrase 3) as a specific protein insufficient in skeletal muscle from myasthenia gravis patients. In this study, we investigated the underlying mechanism of how CA3 insufficiency might contribute to myasthenia gravis. Using an experimental autoimmune myasthenia gravis animal model and the skeletal muscle cell C2C12, we find that inhibition of CAR3 (the mouse homolog of CA3) promotes CHRN internalization via a lipid raft-mediated pathway, leading to accelerated degradation of postsynaptic CHRN. Activation of CAR3 reduces CHRN degradation by suppressing receptor endocytosis. CAR3 exerts this effect by suppressing chaperone-assisted selective autophagy via interaction with BAG3 (BCL2-associated athanogene 3) and by dampening endoplasmic reticulum stress. Collectively, our study illustrates that skeletal muscle cell CAR3 is critical for CHRN homeostasis in the neuromuscular junction, and its deficiency leads to accelerated degradation of CHRN and development of myasthenia gravis, potentially revealing a novel therapeutic approach for this disorder. PMID:28933591
Suppression of CHRN endocytosis by carbonic anhydrase CAR3 in the pathogenesis of myasthenia gravis.
Du, Ailian; Huang, Shiqian; Zhao, Xiaonan; Feng, Kuan; Zhang, Shuangyan; Huang, Jiefang; Miao, Xiang; Baggi, Fulvio; Ostrom, Rennolds S; Zhang, Yanyun; Chen, Xiangjun; Xu, Congfeng
2017-01-01
Myasthenia gravis is an autoimmune disorder of the neuromuscular junction manifested as fatigable muscle weakness, which is typically caused by pathogenic autoantibodies against postsynaptic CHRN/AChR (cholinergic receptor nicotinic) in the endplate of skeletal muscle. Our previous studies have identified CA3 (carbonic anhydrase 3) as a specific protein insufficient in skeletal muscle from myasthenia gravis patients. In this study, we investigated the underlying mechanism of how CA3 insufficiency might contribute to myasthenia gravis. Using an experimental autoimmune myasthenia gravis animal model and the skeletal muscle cell C2C12, we find that inhibition of CAR3 (the mouse homolog of CA3) promotes CHRN internalization via a lipid raft-mediated pathway, leading to accelerated degradation of postsynaptic CHRN. Activation of CAR3 reduces CHRN degradation by suppressing receptor endocytosis. CAR3 exerts this effect by suppressing chaperone-assisted selective autophagy via interaction with BAG3 (BCL2-associated athanogene 3) and by dampening endoplasmic reticulum stress. Collectively, our study illustrates that skeletal muscle cell CAR3 is critical for CHRN homeostasis in the neuromuscular junction, and its deficiency leads to accelerated degradation of CHRN and development of myasthenia gravis, potentially revealing a novel therapeutic approach for this disorder.
Santafe, M M; Garcia, N; Lanuza, M A; Tomàs, M; Besalduch, N; Tomàs, J
2009-04-01
We studied the relation among calcium inflows, voltage-dependent calcium channels (VDCC), presynaptic muscarinic acetylcholine receptors (mAChRs), and protein kinase C (PKC) activity in the modulation of synapse elimination. We used intracellular recording to determine the synaptic efficacy in dually innervated endplates of the levator auris longus muscle of newborn rats during axonal competition in the postnatal synaptic elimination period. In these dual junctions, the weak nerve terminal was potentiated by partially reducing calcium entry (P/Q-, N-, or L-type VDCC-specific block or 500 muM magnesium ions), M1- or M4-type selective mAChR block, or PKC block. Moreover, reducing calcium entry or blocking PKC or mAChRs results in unmasking functionally silent nerve endings that now recover neurotransmitter release. Our results show interactions between these molecules and indicate that there is a release inhibition mechanism based on an mAChR-PKC-VDCC intracellular cascade. When it is fully active in certain weak motor axons, it can depress ACh release and even disconnect synapses. We suggest that this mechanism plays a central role in the elimination of redundant neonatal synapses, because functional axonal withdrawal can indeed be reversed by mAChRs, VDCCs, or PKC block.
2017-12-11
jsc2017e137338 - At the Cosmonaut Hotel crew quarters in Baikonur, Kazakhstan, Expedition 54-55 prime crewmember Norishige Kanai of the Japan Aerospace Exploration Agency (JAXA) tries his hand at a game of billiards Dec. 11 during a break in pre-launch training while backup crewmember Jeanette Epps of NASA looks on. Kanai, Scott Tingle of NASA and Anton Shkaplerov of the Russian Federal Space Agency (Roscosmos) will launch Dec. 17 on the Soyuz MS-07 spacecraft from the Baikonur Cosmodrome for a five month mission on the International Space Station...Andrey Shelepin / Gagarin Cosmonaut Training Center.
Kebede, Noah; Francis, Paul S; Barbante, Gregory J; Hogan, Conor F
2015-11-07
A series of aliphatic tertiary amines (HEPES, POPSO, EPPS and BIS-TRIS) commonly used to buffer the pH in biological experiments, were examined as alternative, non-toxic co-reactants for the electrogenerated chemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(ii) ([Ru(bpy)3](2+)). These were found to be very attractive as "multi-tasking" reagents, serving not only as co-reactants, but also fulfiling the roles of pH buffer and supporting electrolyte within an aqueous environment; thus significantly simplifying the overall ECL analysis. Sub-nanomolar detection limits were obtained for [Ru(bpy)3](2+) in the presence of BIS-TRIS, making this species an valuable option for co-reactant ECL-based bioanalytical applications.
The Polarized Deuteron Breakup Experiment at COSY
NASA Astrophysics Data System (ADS)
Rathmann, F.; Barsov, S.; Dymov, S.; Kacharava, A.; Khoukaz, A.; Komarov, V.; Kulikov, A.; Kurbatov, A.; Lang, N.; Lehmann, I.; Lorentz, B.; Macharashvili, G.; Mussgiller, A.; Paetz gen. Schieck, H.; Schleichert, R.; Seyfarth, H.; Steffens, E.; Ströher, H.; Uzikov, Yu.; Yaschenko, S.; Zalikhanov, B.
2003-07-01
A study of the deuteron breakup reaction pd → (pp)n with forward emission of a fast proton pair with small excitation energy Epp < 3 MeV has been performed using the ANKE spectrometer at COSY Jülich. The differential cross section of the breakup reaction, averaged up to 8° over the cm polar angle of the total momentum of the pp pairs, has been obtained at six proton beam energies Tp = 0.6, 0.7, 0.8, 0.95, 1.35, and 1.9 GeV. A first measurement of the vector analyzing power Ayp has been carried out, using a polarization normalization obtained with the EDDA detector. In addition, for the first time asymmetries of p⃗d elastic scattering at Tp = 500 MeV have been recorded with the spectator setup at ANKE.
Rodrigues, Kamilla C. M.; Chibli, Lucas A.; Santos, Bruna C. S.; Temponi, Vanessa S.; Pinto, Nícolas C. C.; Scio, Elita; Del-Vechio-Vieira, Glauciemar; Alves, Maria S.; Sousa, Orlando V.
2016-01-01
Vernonia polyanthes Less. (Asteraceae), popularly known as “assa-peixe”, is a plant species used in Brazilian traditional medicine for the treatment of cutaneous damage, cicatrization, inflammation, and rheumatism. Based on these ethnopharmacological findings, the current study evaluated the topical anti-inflammatory effects of the hexane (HEVP) and ethyl acetate (EAEVP) extracts from V. polyanthes leaves in experimental models of skin inflammation. Chemical characterization was carried out by HPLC–UV/DAD analysis. Anti-inflammatory activity was evaluated using Croton oil-, arachidonic acid (AA)-, phenol-, ethyl phenylpropiolate (EPP)-, and capsaicin-induced ear edema models in mice. Histopathological evaluation and measurements of myeloperoxidase (MPO) and N-acetyl-β-d-glucosaminidase (NAG) enzymes were also performed. Rutin, luteolin, and apigenin were identified in EAEVP. Topically applied HEVP and EAEVP significantly (p < 0.05, p < 0.01 or p < 0.001) reduced edema induced by five different irritants at the doses tested (0.1, 0.5 and 1.0 mg/ear). Histopathological analysis revealed a reduction of edema, inflammatory cell infiltration, and vasodilation. In addition, the enzymes activity (MPO and NAG) in the ear tissues was reduced by the topical treatment of HEVP and EAEVP (p < 0.05, p < 0.01 or p < 0.001). The results suggest that V. polyanthes leaves are effective against cutaneous damage, which support its traditional use and open up new possibilities for the treatment of skin disorders. PMID:27916942
Feng, Zhiyun; Chen, Lunhao; Hu, Xiaojian; Yang, Ge; Wang, Yue; Chen, Zhong
2018-04-11
An experimental study. The aim of this study was to determine the effect of polymethylmethacrylate (PMMA) augmentation on the adjacent disc. Vertebral augmentation with PMMA reportedly may predispose the adjacent vertebra to fracture. The influence of PMMA augmentation on the adjacent disc, however, remains unclear. Using a retroperitoneal approach, PMMA augmentation was performed for 23 rabbits. For each animal, at least one vertebra was augmented with 0.2 to 0.3 mL PMMA. The disc adjacent to the augmented vertebra and a proximal control disc were studied using magnetic resonance (MR) imaging, histological and molecular level evaluation at 1, 3, and 6 months postoperatively. Marrow contact channels in the endplate were quantified in histological slices and number of invalid channels (those without erythrocytes inside) was rated. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) was performed to determine disc cell apoptosis. On MR images, the signal and height of the adjacent disc did not change 6 months after vertebral augmentation. Histological scores of the adjacent disc increased over time, particularly for the nucleus pulposus. The adjacent disc had greater nucleus degeneration score than the control disc at 3 months (5.7 vs. 4.5, P < 0.01) and 6 months (6.9 vs. 4.4, P < 0.001). There were more invalid marrow contact channels in the endplate of augmented vertebra than the control (43.3% vs. 11.1%, P < 0.01). mRNA of ADAMTS-5, MMP-13, HIF-1α, and caspase-3 were significantly upregulated in the adjacent disc at 3 and 6 months (P < 0.05 for all). In addition, there were more TUNEL-positive cells in the adjacent disc than in the control disc (43.4% vs. 24.0%, P < 0.05) at 6 months postoperatively. Vertebral augmentation can induce early degenerative signs in the adjacent disc, which may be due to impaired nutrient supply to the disc. N/A.
van der Keylen, Piet; Garreis, Fabian; Steigleder, Ruth; Sommer, Daniel; Neuhuber, Winfried L; Wörl, Jürgen
2016-05-01
Enteric co-innervation is a peculiar innervation pattern of striated esophageal musculature. Both anatomical and functional data on enteric co-innervation related to various transmitters have been collected in different species, although its function remains enigmatic. However, it is unclear whether catecholaminergic components are involved in such a co-innervation. Thus, we examined to identify catecholaminergic neuronal elements and clarify their relationship to other innervation components in the esophagus, using immunohistochemistry with antibodies against tyrosine hydroxylase (TH), vesicular acetylcholine transporter (VAChT), choline acetyltransferase (ChAT) and protein gene product 9.5 (PGP 9.5), α-bungarotoxin (α-BT) and PCR with primers for amplification of cDNA encoding TH and dopamine-β-hydroxylase (DBH). TH-positive nerve fibers were abundant throughout the myenteric plexus and localized on about 14% of α-BT-labelled motor endplates differing from VAChT-positive vagal nerve terminals. TH-positive perikarya represented a subpopulation of only about 2.8% of all PGP 9.5-positive myenteric neurons. Analysis of mRNA showed both TH and DBH transcripts in the mouse esophagus. As ChAT-positive neurons in the compact formation of the nucleus ambiguus were negative for TH, the TH-positive nerve varicosities on motor endplates are presumably of enteric origin, although a sympathetic origin cannot be excluded. In the medulla oblongata, the cholinergic ambiguus neurons were densely supplied with TH-positive varicosities. Thus, catecholamines may modulate vagal motor innervation of esophageal-striated muscles not only at the peripheral level via enteric co-innervation but also at the central level via projections to the nucleus ambiguus. As Parkinson's disease, with a loss of central dopaminergic neurons, also affects the enteric nervous system and dysphagia is prevalent in patients with this disease, investigation of intrinsic catecholamines in the esophagus may be worthwhile to understand such a symptom.
Mattei, Tobias A; Rehman, Azeem A; Teles, Alisson R; Aldag, Jean C; Dinh, Dzung H; McCall, Todd D
2017-01-01
In order to evaluate the predictive effect of non-invasive preoperative imaging methods on surgical outcomes of lumbar fusion for patients with degenerative disc disease (DDD) and refractory chronic axial low back pain (LBP), the authors conducted a retrospective review of 45 patients with DDD and refractory LBP submitted to anterior lumbar interbody fusion (ALIF) at a single center from 2007 to 2010. Surgical outcomes - as measured by Visual Analog Scale (VAS/back pain) and Oswestry Disability Index (ODI) - were evaluated pre-operatively and at 6 weeks, 3 months, 6 months, and 1 year post-operatively. Linear mixed-effects models were generated in order to identify possible preoperative imaging characteristics (including bone scan/99mTc scintigraphy increased endplate uptake, Modic endplate changes, and disc degeneration graded according to Pfirrmann classification) which may be predictive of long-term surgical outcomes . After controlling for confounders, a combined score, the Lumbar Fusion Outcome Score (LUFOS), was developed. The LUFOS grading system was able to stratify patients in two general groups (Non-surgical: LUFOS 0 and 1; Surgical: LUFOS 2 and 3) that presented significantly different surgical outcomes in terms of estimated marginal means of VAS/back pain (p = 0.001) and ODI (p = 0.006) beginning at 3 months and continuing up to 1 year of follow-up. In conclusion, LUFOS has been devised as a new practical and surgically oriented grading system based on simple key parameters from non-invasive preoperative imaging exams (magnetic resonance imaging/MRI and bone scan/99mTc scintigraphy) which has been shown to be highly predictive of surgical outcomes of patients undergoing lumbar fusion for treatment for refractory chronic axial LBP.
Yusof, Mohd Imran; Nadarajan, Eswaran; Abdullah, Mohd Shafie
2014-06-15
Cross-sectional study on the measurement of relevant magnetic resonance imaging parameters in 100 patients presented for lumbar spine assessment. To determine anatomical position of lumbar plexus and major blood vessels in relation to vertebral body and anterior edge of psoas muscle at L3-L4 and L4-L5 and to define the safe working zone for transpsoas approach for lumbar fusion. Lateral transpsoas lumbar interbody fusion has been shown to be safe and provides alternative for lumbar fusion. However, proximity of neurovascular structures may not allow a safe passage for this procedure in the Asian population. Relevant parameters were measured from axial magnetic resonance images and analyzed, including the psoas muscle and vertebrae endplate diameters, lumbar plexus and psoas muscle distance, lumbar plexus and vertebra body distance, and vena cava to the anterior vertebrae body diameters. The mean anteroposterior diameters of the right and left psoas muscle ranged from 44.0 to 58.6 mm and 44.8 to 54.0 mm, respectively. The mean anteroposterior diameters of vertebra endplate of L3, L4, and L5 were 38.2 mm, 39.3 mm, and 41.4 mm, respectively. The mean distance of posterior border of vena cava from the vertebra body was 4.5 mm at L3-L4 and 14.1 mm at L4-L5. L3-L4 fusion is feasible at both sides in both sexes; however, at L4-L5 level, the procedure is feasible only on the left side. The safe working zone for transpsoas approach to lumbar spine is significantly narrower at L4-L5 in both sexes. Anterior edge of psoas muscle can be used as a reliable guide to locate lumbar plexus within psoas muscle. N/A.
Back pain in space and post-flight spine injury: Mechanisms and countermeasure development
NASA Astrophysics Data System (ADS)
Sayson, Jojo V.; Lotz, Jeffrey; Parazynski, Scott; Hargens, Alan R.
2013-05-01
During spaceflight many astronauts experience moderate to severe lumbar pain and deconditioning of paraspinal muscles. There is also a significant incidence of herniated nucleus pulposus (HNP) in astronauts post-flight being most prevalent in cervical discs. Relief of in-flight lumbar back pain is facilitated by assuming a knee-to-chest position. The pathogenesis of lumbar back pain during spaceflight is most likely discogenic and somatic referred (from the sinuvertebral nerves) due to supra-physiologic swelling of the lumbar intervertebral discs (IVDs) due to removal of gravitational compressive loads in microgravity. The knee-to-chest position may reduce lumbar back pain by redistributing stresses through compressive loading to the IVDs, possibly reducing disc volume by fluid outflow across IVD endplates. IVD stress redistribution may reduce Type IV mechanoreceptor nerve impulse propagation in the annulus fibrosus and vertebral endplate resulting in centrally mediated pain inhibition during spinal flexion. Countermeasures for lumbar back pain may include in-flight use of: (1) an axial compression harness to prevent excessive IVD expansion and spinal column elongation; (2) the use of an adjustable pulley exercise developed to prevent atrophy of spine muscle stabilisers; and (3) other exercises that provide Earth-like annular stress with low-load repetitive active spine rotation movements. The overall objective of these countermeasures is to promote IVD health and to prevent degenerative changes that may lead to HNPs post-flight. In response to "NASA's Critical Path Roadmap Risks and Questions" regarding disc injury and higher incidence of HNPs after space flight (Integrated Research Plan Gap-B4), future studies will incorporate pre- and post-flight imaging of International Space Station long-duration crew members to investigate mechanisms of lumbar back pain as well as degeneration and damage to spinal structures. Quantitative results on morphological, biochemical, metabolic, and kinematic spinal changes in the lumbar spine may aid further development of countermeasures to prevent lumbar back pain in microgravity and reduce the incidence of HNPs post-flight.
Li, Yang; Zhang, Zhenjun; Liao, Zhenhua; Mo, Zhongjun; Liu, Weiqiang
2017-10-01
Finite element models have been widely used to predict biomechanical parameters of the cervical spine. Previous studies investigated the influence of position of rotational centers of prostheses on cervical biomechanical parameters after 1-level total disc replacement. The purpose of this study was to explore the effects of axial position of rotational centers of prostheses on cervical biomechanics after 2-level total disc replacement. A validated finite element model of C3-C7 segments and 2 prostheses, including the rotational center located at the superior endplate (SE) and inferior endplate (IE), was developed. Four total disc replacement models were used: 1) IE inserted at C4-C5 disc space and IE inserted at C5-C6 disc space (IE-IE), 2) IE-SE, 3) SE-IE, and 4) SE-SE. All models were subjected to displacement control combined with a 50 N follower load to simulate flexion and extension motions in the sagittal plane. For each case, biomechanical parameters, including predicted moments, range of rotation at each level, facet joint stress, and von Mises stress on the ultra-high-molecular-weight polyethylene core of the prostheses, were calculated. The SE-IE model resulted in significantly lower stress at the cartilage level during extension and at the ultra-high-molecular-weight polyethylene cores when compared with the SE-SE construct and did not generate hypermotion at the C4-C5 level compared with the IE-SE and IE-IE constructs. Based on the present analysis, the SE-IE construct is recommended for treating cervical disease at the C4-C6 level. This study may provide a useful model to inform clinical operations. Copyright © 2017 Elsevier Inc. All rights reserved.
Lift enhancement by trapped vortex
NASA Technical Reports Server (NTRS)
Rossow, Vernon J.
1992-01-01
The viewgraphs and discussion of lift enhancement by trapped vortex are provided. Efforts are continuously being made to find simple ways to convert wings of aircraft from an efficient cruise configuration to one that develops the high lift needed during landing and takeoff. The high-lift configurations studied here consist of conventional airfoils with a trapped vortex over the upper surface. The vortex is trapped by one or two vertical fences that serve as barriers to the oncoming stream and as reflection planes for the vortex and the sink that form a separation bubble on top of the airfoil. Since the full three-dimensional unsteady flow problem over the wing of an aircraft is so complicated that it is hard to get an understanding of the principles that govern the vortex trapping process, the analysis is restricted here to the flow field illustrated in the first slide. It is assumed that the flow field between the two end plates approximates a streamwise strip of the flow over a wing. The flow between the endplates and about the airfoil consists of a spanwise vortex located between the suction orifices in the endplates. The spanwise fence or spoiler located near the nose of the airfoil serves to form a separated flow region and a shear layer. The vorticity in the shear layer is concentrated into the vortex by withdrawal of fluid at the suction orifices. As the strength of the vortex increases with time, it eventually dominates the flow in the separated region so that a shear or vertical layer is no longer shed from the tip of the fence. At that point, the vortex strength is fixed and its location is such that all of the velocity contributions at its center sum to zero thereby making it an equilibrium point for the vortex. The results of a theoretical analysis of such an idealized flow field are described.
Kuisma, Mari; Karppinen, Jaro; Haapea, Marianne; Niinimäki, Jaakko; Ojala, Risto; Heliövaara, Markku; Korpelainen, Raija; Kaikkonen, Kaisu; Taimela, Simo; Natri, Antero; Tervonen, Osmo
2008-04-16
Modic changes are bone marrow lesions visible in magnetic resonance imaging (MRI), and they are assumed to be associated with symptomatic intervertebral disc disease, especially changes located at L5-S1. Only limited information exists about the determinants of Modic changes. The objective of this study was to evaluate the determinants of vertebral endplate (Modic) changes, and whether they are similar for Modic changes and severe disc degeneration focusing on L5-S1 level. 228 middle-aged male workers (159 train engineers and 69 sedentary factory workers) from northern Finland underwent sagittal T1- and T2-weighted MRI. Modic changes and disc degeneration were analyzed from the scans. The participants responded to a questionnaire including items of occupational history and lifestyle factors. Logistic regression analysis was used to evaluate the associations between selected determinants (age, lifetime exercise, weight-related factors, fat percentage, smoking, alcohol use, lifetime whole-body vibration) and Modic type I and II changes, and severe disc degeneration (= grade V on Pfirrmann's classification). The prevalences of the Modic changes and severe disc degeneration were similar in the occupational groups. Age was significantly associated with all degenerative changes. In the age-adjusted analyses, only weight-related determinants (BMI, waist circumference) were associated with type II changes. Exposure to whole-body vibration, besides age, was the only significant determinant for severe disc degeneration. In the multivariate model, BMI was associated with type II changes at L5-S1 (OR 2.75 per one SD = 3 unit increment in BMI), and vibration exposure with severe disc degeneration at L5-S1 (OR 1.08 per one SD = 11-year increment in vibration exposure). Besides age, weight-related factors seem important in the pathogenesis of Modic changes, whereas whole-body vibration was the only significant determinant of severe disc degeneration.
Kuisma, Mari; Karppinen, Jaro; Haapea, Marianne; Niinimäki, Jaakko; Ojala, Risto; Heliövaara, Markku; Korpelainen, Raija; Kaikkonen, Kaisu; Taimela, Simo; Natri, Antero; Tervonen, Osmo
2008-01-01
Background Modic changes are bone marrow lesions visible in magnetic resonance imaging (MRI), and they are assumed to be associated with symptomatic intervertebral disc disease, especially changes located at L5-S1. Only limited information exists about the determinants of Modic changes. The objective of this study was to evaluate the determinants of vertebral endplate (Modic) changes, and whether they are similar for Modic changes and severe disc degeneration focusing on L5-S1 level. Methods 228 middle-aged male workers (159 train engineers and 69 sedentary factory workers) from northern Finland underwent sagittal T1- and T2-weighted MRI. Modic changes and disc degeneration were analyzed from the scans. The participants responded to a questionnaire including items of occupational history and lifestyle factors. Logistic regression analysis was used to evaluate the associations between selected determinants (age, lifetime exercise, weight-related factors, fat percentage, smoking, alcohol use, lifetime whole-body vibration) and Modic type I and II changes, and severe disc degeneration (= grade V on Pfirrmann's classification). Results The prevalences of the Modic changes and severe disc degeneration were similar in the occupational groups. Age was significantly associated with all degenerative changes. In the age-adjusted analyses, only weight-related determinants (BMI, waist circumference) were associated with type II changes. Exposure to whole-body vibration, besides age, was the only significant determinant for severe disc degeneration. In the multivariate model, BMI was associated with type II changes at L5-S1 (OR 2.75 per one SD = 3 unit increment in BMI), and vibration exposure with severe disc degeneration at L5-S1 (OR 1.08 per one SD = 11-year increment in vibration exposure). Conclusion Besides age, weight-related factors seem important in the pathogenesis of Modic changes, whereas whole-body vibration was the only significant determinant of severe disc degeneration. PMID:18416819
van der Heijde, Désirée; Gladman, Dafna D; Kishimoto, Mitsumasa; Okada, Masato; Rathmann, Suchitrita S; Moriarty, Susan R; Shuler, Catherine L; Carlier, Hilde; Benichou, Olivier; Mease, Philip J
2018-03-01
To evaluate the efficacy and safety of ixekizumab (IXE), an interleukin 17A antagonist, in patients with psoriatic arthritis (PsA) after 52 weeks in a phase III study. Patients were initially randomly assigned to IXE 80 mg every 2 weeks (IXEQ2W) or every 4 weeks (IXEQ4W) after a 160-mg starting dose, placebo (PBO), or adalimumab (ADA) 40 mg Q2W. At Week 24 (Week 16 for inadequate responders), ADA (8-week washout before starting IXE) and PBO patients were rerandomized to IXEQ2W or IXEQ4W. Six treatment groups were evaluated in the extension period (weeks 24-52): IXEQ2W/IXEQ2W, IXEQ4W/IXEQ4W, ADA/IXEQ2W, ADA/IXEQ4W, PBO/IXEQ2W, and PBO/IXEQ4W. The extension period population (EPP) included patients who received ≥ 1 dose of study medication during the extension period. There were 381/417 (91.4%) patients who entered the extension period. In the IXEQ4W/IXEQ4W and IXEQ2W/IXEQ2W groups (EPP), respectively, American College of Rheumatology (ACR)20 (69.1% and 68.8%), ACR50 (54.6% and 53.1%), and ACR70 (39.2% and 39.6%) response rates were sustained at Week 52. Patients rerandomized to IXE also demonstrated efficacy measured by ACR response rates at Week 52. A similar pattern was observed for Psoriasis Area and Severity Index outcomes. Radiographic progression in all 6 groups was minimal. The most frequently reported treatment-emergent adverse events (≥ 4%) were nasopharyngitis, injection site reaction, injection site erythema, upper respiratory tract infection, and back pain. No deaths were reported, and serious adverse event frequency was 0-4% with IXE. During the extension period, IXEQ4W or IXEQ2W treatment demonstrated sustained efficacy in key PsA domains with a safety profile consistent with other studies investigating IXE. Clinical trial number: NCT01695239; EudraCT 2011-002326-49.
Yi, Zhi-hui; Feng, Li; Wen, Mao-yao; Liu, Jian-rong; Yang, Li
2014-05-01
To investigate the association between esophageal motility and acid reflux in patients with gastroesophageal reflux disease (GERD). A total of 94 patients with typical reflux symptoms such as heartburn, regurgitation and chest pain, whose score (Sc) of reflux diagnostic questionnaire (RDQ) was greater than or equal to 12 were enrolled in the study. Each participant was evaluated by upper gastrointestinal endoscopy, high resolution manometry (HRM) of esophagus and 24 h esophageal pH monitoring. The participants were divided into groups of reflux esophagitis (RE) and non-erosive reflux disease (NERD) on the basis of endoscopy findings. The 24 h esophageal pH monitoring categorized participants into physiologic reflux (pH) and pathologic reflux (pH+). The characteristics of esophageal motility and acid reflux were compared between the two groups of participants. Lower but non-significant differences (P > 0.05) were found in pressure of lower esophageal sphincter (LESP), length of lower esophageal sphincter (LESL), esophageal contraction amplitude (CA), distal contractile integral (DCI) and effective peristalsis proportion (EPP) in the participants in the RE group compared with those in the NERD group. Participants in the RE group had significantly higher prevalence of reduced LESP (63.0% vs. 31.7%, P < 0.01) and hiatus hernia (HH) (37.0% vs. 14.3%, P < 0.05) than those in the NERD group, pH+ was more prevalent in the RE group than in the NERD group (63.0% vs. 17.5%, P < 0.01). Indicators of 24 h esophageal pH monitoring were significantly higher in participants in the RE group compared with those in the NERD group (P < 0.05). Participants with pH+ had significantly lower LESP, CA and higher HH and prevalence of reduced LESP compared with those with pH (P < 0.05). LESL, DCI and EPP were lower in those with pH+ compared with those with pH-, but without statistical significance (P > 0.05). RE is closely associated with acid reflux and hiatus hernia. Esophageal dysmotility is more likely to appear in patients with pH+. The interaction of acid reflux and esophageal dysmotility may play a role in GERD.
Experimentally Reproducing Thermal Breakdown of Rock at Earth's Surface
NASA Astrophysics Data System (ADS)
Eppes, M. C.; Griffiths, L.; Heap, M. J.; Keanini, R.; Baud, P.
2016-12-01
Thermal stressing induces microcrack growth in rock in part due to thermal expansion mismatch between different minerals, mineral phases, or crystalline axes and/or thermal gradients in the entire rock mass. This knowledge is largely derived from experimental studies of thermal microcracking, typically under conditions of very high temperatures (hundreds of °C). Thermal stressing at lower temperatures has received significantly less attention despite the fact that it may play an important role in rock breakdown at and near Earth's surface (Aldred et al., 2015; Collins and Stock, 2016). In particular, Eppes et al. (2016) attribute recorded Acoustic Emissions (AE) from a highly instrumented granite boulder sitting on the ground in natural conditions to subcritical crack growth driven by thermal stresses arising from a combination of solar- and weather-induced temperature changes; however the maximum temperature the boulder experienced was just 65 °C. In order to better understand these results without complicating factors of a natural environment, we conducted controlled laboratory experiments on cylindrical samples (40 mm length and 20 mm diameter) cored from the same granite as the Eppes et al. (2016) experiment, subjecting them to temperature fluctuations that reproduced the field measurements. We used a novel experimental configuration whereby two high temperature piezo-transducers are each in contact with an opposing face of the sample. The servo-controlled uniaxial press compensates for the thermal expansion and contraction of the pistons and the sample, keeping the coupling between the transducers and the sample, and the axial force acting on the sample, constant throughout. The system records AE, as well as P-wave velocity, both independent proxies for microfracture, as well as strain and temperature. Preliminary tests, heating and cooling granite at a rate of 1 °C/min, show that a large amount of AE occurs at temperatures as low as 100 °C. Ultimately, by subjecting the samples to more realistic temperature cycles and by then comparing those results to field data and to modelling output for thermal-stress related fracture, we hope to expand our understanding of the specific environmental conditions that lead to thermal-stress related rock breakdown at Earth's surface.
NASA Astrophysics Data System (ADS)
Petrone, A.; Preti, F.
2009-04-01
The use of Soil Bio-Engineering techniques in Developing countries is a relevant issue for Disaster mitigation, environmental restoration and poverty reduction. Research on authochtonal plants suitable for this kind of works and on economic efficiency is essential for the divulgation of this Discipline. The present paper is focused on this two issues related to the realization of various typologies of Soil Bio-engineering works in the Humid tropic of Nicaragua. In the area of Río Blanco, located in the Department of Matagalpa, Soil bio-engineering installations were built in several sites. The particular structures built were: drainages with live fascine mattress, a live palisade, a vegetated live crib wall for riverbank protection, a vegetative covering made of a metallic net and biotextile coupled with a live palisade made of bamboo. In order to evaluate the suitability of the various plants used in the works, monitorings were performed, one in the live palisade alongside an unpaved road and the other on the live crib wall along a riverbank, collecting survival rate and morphological parameters data. Concerning the economic efficiency we proceed to a financial analysis of the works and once the unit price was obtained, we converted the amount in EPP Dollars (Equal Purchasing Power) in order to compare the Nicaraguan context with the Italian one. Among the used species we found that Madero negro (Gliricidia sepium) and Roble macuelizo (Tabebuia rosea) are adequate for Soil-bioengineering measure on slopes while Helequeme (Erythrina fusca) reported a successful behaviour only in the crib wall for riverbank protection. In the comparison of the costs in Nicaragua and in Italy, the unit price reduction for the central American country ranges between 1.5 times (for the vegetative covering) and almost 4 times (for the fascine mattress) if it's used the EPP dollar exchange rate. Thus, a conclusion can be reached with regard to hydrological-risk mitigating actions performed on a basin scale and through naturalistic techniques: not only are they technically attainable, even in hardship areas (by maximizing the contribution of the local labor force and minimizing the use of mechanical equipment), but they are also economically sustainable.
Soil bio-engineering for risk mitigation and environmental restoration in a humid tropical area
NASA Astrophysics Data System (ADS)
Petrone, A.; Preti, F.
2009-07-01
The use of soil bio-engineering techniques in developing countries is a relevant issue for disaster mitigation, environmental restoration and poverty reduction. Research on authochtonal plants suitable for this kind of works and on economic efficiency is essential for the divulgation of such techniques. The present paper is focused on this two issues related to the realization of various typologies of soil bio-engineering works in the humid tropic of Nicaragua. In the area of Río Blanco, located in the Department of Matagalpa, soil bio-engineering installations were built in several sites. The particular structures built were: drainages with live fascine mattress, a live palisade, a vegetated live crib wall for riverbank protection, a vegetative covering made of a metallic net and biotextile coupled with a live palisade made of bamboo. In order to evaluate the suitability of the various plants used in the works, monitorings were performed, one in the live palisade alongside an unpaved road and the other on the live crib wall along a riverbank, collecting survival rate and morphological parameters data. Concerning the economic efficiency we proceed to a financial analysis of the works and once the unit price was obtained, we converted the amount in EPP Dollars (Equal Purchasing Power) in order to compare the Nicaraguan context with the Italian one. Among the used species we found that Madero negro (Gliricidia sepium) and Roble macuelizo (Tabebuia rosea) are adequate for soil-bioengineering measure on slopes while Helequeme (Erythrina fusca) reported a successful behaviour only in the crib wall for riverbank protection. In the comparison of the costs in Nicaragua and in Italy, the unit price reduction for the Central American country ranges between 1.5 times (for the vegetative covering) and almost 4 times (for the fascine mattress) if it's used the EPP dollar exchange rate. Conclusions are reached with regard to hydrological-risk mitigating actions performed on a basin scale and through naturalistic (live) interventions: not only are they socially and technically attainable, even in hardship areas (by maximizing the contribution of the local labor force and minimizing the use of mechanical equipment), but they are also economically sustainable.
Soil bioengineering for risk mitigation and environmental restoration in a humid tropical area
NASA Astrophysics Data System (ADS)
Petrone, A.; Preti, F.
2010-02-01
The use of soil bio-engineering techniques in developing countries is a relevant issue for disaster mitigation, environmental restoration and poverty reduction. Research on the autochthonal plants suitable for these kinds of interventions and on the economic efficiency of the interventions is essential for the dissemination of such techniques. The present paper is focused on these two issues as related to the realization of various typologies of soil bioengineering works in the humid tropics of Nicaragua. In the area of Río Blanco, located in the Department of Matagalpa, soil bioengineering installations were built in several sites. The particular structures built were: drainages with live fascine mattress, a live palisade, a vegetated live crib wall for riverbank protection, a vegetative covering made of a metallic net and biotextile coupled with a live palisade made of bamboo. In order to evaluate the suitability of the various plants used in these works, monitoring was performed, one on the live palisade alongside an unpaved road and the other on the live crib wall along a riverbank, by collecting data on survival rate and morphological parameters. Concerning economic efficiency, we proceeded to a financial analysis of the works. Once the unit price was obtained, we converted the amount into EPP Dollars (Equal Purchasing Power) in order to compare the Nicaraguan context with the European one. Among the species used we found that Gliricidia sepium (local common name: Madero negro) and Tabebuia rosea (local common name: Roble macuelizo) are adequate for soil bioengineering measures on slopes, while Erythrina fusca (local common name: Helequeme) resulted in successful behaviour only in the crib wall for riverbank protection. In comparing costs in Nicaragua and in Italy, the unit price reduction for Nicaragua ranges from 1.5 times (for the vegetative covering) to almost 4 times (for the fascine mattress), using the EPP dollar exchange rate. Our conclusions with regard to hydrological-risk mitigating actions performed on a basin scale and through naturalistic (live) interventions are that they are not only socially and technically possible, even in hardship areas (by maximizing the contribution of the local labour force and minimizing the use of mechanical equipment), but also economically sustainable.
Ion ejection from a permanent-magnet mini-helicon thruster
NASA Astrophysics Data System (ADS)
Chen, Francis F.
2014-09-01
A small helicon source, 5 cm in diameter and 5 cm long, using a permanent magnet (PM) to create the DC magnetic field B, is investigated for its possible use as an ion spacecraft thruster. Such ambipolar thrusters do not require a separate electron source for neutralization. The discharge is placed in the far-field of the annular PM, where B is fairly uniform. The plasma is ejected into a large chamber, where the ion energy distribution is measured with a retarding-field energy analyzer. The resulting specific impulse is lower than that of Hall thrusters but can easily be increased to relevant values by applying to the endplate of the discharge a small voltage relative to spacecraft ground.
Ion ejection from a permanent-magnet mini-helicon thruster
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chen, Francis F.
2014-09-15
A small helicon source, 5 cm in diameter and 5 cm long, using a permanent magnet (PM) to create the DC magnetic field B, is investigated for its possible use as an ion spacecraft thruster. Such ambipolar thrusters do not require a separate electron source for neutralization. The discharge is placed in the far-field of the annular PM, where B is fairly uniform. The plasma is ejected into a large chamber, where the ion energy distribution is measured with a retarding-field energy analyzer. The resulting specific impulse is lower than that of Hall thrusters but can easily be increased to relevant valuesmore » by applying to the endplate of the discharge a small voltage relative to spacecraft ground.« less
Systematic and reliable multiscale modelling of lithium batteries
NASA Astrophysics Data System (ADS)
Atalay, Selcuk; Schmuck, Markus
2017-11-01
Motivated by the increasing interest in lithium batteries as energy storage devices (e.g. cars/bycicles/public transport, social robot companions, mobile phones, and tablets), we investigate three basic cells: (i) a single intercalation host; (ii) a periodic arrangement of intercalation hosts; and (iii) a rigorously upscaled formulation of (ii) as initiated in. By systematically accounting for Li transport and interfacial reactions in (i)-(iii), we compute the associated chracteristic current-voltage curves and power densities. Finally, we discuss the influence of how the intercalation particles are arranged. Our findings are expected to improve the understanding of how microscopic properties affect the battery behaviour observed on the macroscale and at the same time, the upscaled formulation (iii) serves as an efficient computational tool. This work has been supported by EPSRC, UK, through the Grant No. EP/P011713/1.
Bovine, Gary; Silver, John Russell; Weiner, Marie-France
2012-02-01
Edward Harrison was a distinguished and innovative physician, an educationalist who had a profound influence on the treatment of spinal deformities. He founded the first infirmary for the treatment of spinal diseases in London in 1837. Little is known of this institution but much of Harrison's legacy rests with his disciples who followed Harrison's principles of treatment to treat spinal deformity. Like Harrison they were unconventional individuals, influenced by religious beliefs and liberal political and social ideologies. After his death, initially they followed his methods of treatment but subsequently they were not afraid to pursue new forms of treatment including homeopathy at a time when traditional medicine had little to offer.
Lisboa, Antonio; Melaré, Rodolfo; Franco, Junia R B; Bis, Carolina V; Gracia, Marta; Ponce-Soto, Luis A; Marangoni, Sérgio; Rodrigues-Simioni, Léa; da Cruz-Höfling, Maria Alice; Rocha, Thalita
2016-01-01
Neuromuscular preparations exposed to B. marajoensis venom show increases in the frequency of miniature end-plate potentials and twitch tension facilitation followed by presynaptic neuromuscular paralysis, without evidences of muscle damage. Considering that presynaptic toxins interfere into the machinery involved in neurotransmitter release (synaptophysin, synaptobrevin, and SNAP25 proteins), the main objective of this communication is to analyze, by immunofluorescence and western blotting, the expression of the synaptic proteins, synaptophysin, synaptobrevin, and SNAP25 and by myography, light, and transmission electron microscopy the pathology of motor nerve terminals and skeletal muscle fibres of chick biventer cervicis preparations (CBC) exposed in vitro to BmjeTX-I and BmjeTX-II toxins from B. marajoensis venom. CBC incubated with toxins showed irreversible twitch tension blockade and unaffected KCl- and ACh-evoked contractures, and the positive colabelling of acetylcholine receptors confirmed that their action was primarily at the motor nerve terminal. Hypercontraction and loose myofilaments and synaptic vesicle depletion and motor nerve damage indicated that the toxins displayed both myotoxic and neurotoxic effect. The blockade resulted from interference on synaptophysin, synaptobrevin, and SNAP25 proteins leading to the conclusion that BmjeTX-I and BmjeTX-II affected neurotransmitter release machinery by preventing the docking of synaptic vesicles to the axolemma of the nerve terminal.
Endoscopic Pubic Symphysectomy for Athletic Osteitis Pubis
Matsuda, Dean K.; Sehgal, Bantoo; Matsuda, Nicole A.
2015-01-01
Osteitis pubis is a common form of athletic pubalgia associated with femoroacetabular impingement. Endoscopic pubic symphysectomy was developed as a less invasive option than open surgical curettage for recalcitrant osteitis pubis. This technical note demonstrates the use of the anterior and suprapubic portals in the supine lithotomy position for endoscopic burr resection of pubic symphyseal fibrocartilage and hyaline endplates. Key steps include use of the suprapubic portal for burr resection of the posteroinferior symphysis and preservation of the posterior and arcuate ligaments. Endoscopic pubic symphysectomy is a minimally invasive bone-conserving surgery that retains stability and may be useful in the treatment of recalcitrant osteitis pubis or osteoarthritis. It nicely complements arthroscopic surgery for femoroacetabular impingement and may find broader application in this group of co-affected athletes. PMID:26258039
Endoscopic Pubic Symphysectomy for Athletic Osteitis Pubis.
Matsuda, Dean K; Sehgal, Bantoo; Matsuda, Nicole A
2015-06-01
Osteitis pubis is a common form of athletic pubalgia associated with femoroacetabular impingement. Endoscopic pubic symphysectomy was developed as a less invasive option than open surgical curettage for recalcitrant osteitis pubis. This technical note demonstrates the use of the anterior and suprapubic portals in the supine lithotomy position for endoscopic burr resection of pubic symphyseal fibrocartilage and hyaline endplates. Key steps include use of the suprapubic portal for burr resection of the posteroinferior symphysis and preservation of the posterior and arcuate ligaments. Endoscopic pubic symphysectomy is a minimally invasive bone-conserving surgery that retains stability and may be useful in the treatment of recalcitrant osteitis pubis or osteoarthritis. It nicely complements arthroscopic surgery for femoroacetabular impingement and may find broader application in this group of co-affected athletes.
Cohen, A S; Olek, A J
1989-01-01
A soluble toxic extract derived from spine tissue of the lionfish (Pterois volitans) decreased heart rate and force of contraction in isolated clam and frog hearts. These actions were due to the presence of micromolar concentrations of acetylcholine in the extract. Toxicity was retained after hydrolysis of acetylcholine by exogenous acetylcholinesterase, but heart function was no longer affected. Toxin treated in this way induced muscle fibrillation in an isolated nerve-muscle preparation, followed by blockade of neuromuscular transmission. Bursts of transient depolarizations were recorded at the muscle endplate shortly after toxin addition that correlated in time with the duration of toxin-induced muscle fibrillation. These effects are thought to be due to the increased release and then depletion of acetylcholine from the nerve terminal.
NASA Technical Reports Server (NTRS)
Garland, D. B.; Harris, J. L.
1980-01-01
Static and forward speed tests were made in a 40 multiplied by 80 foot wind tunnel of a large-scale, ejector-powered V/STOL aircraft model. Modifications were made to the model following earlier tests primarily to improve longitudinal acceleration capability during transition from hovering to wingborne flight. A rearward deflection of the fuselage augmentor thrust vector was shown to be beneficial in this regard. Other augmentor modifications were tested, notably the removal of both endplates, which improved acceleration performance at the higher transition speeds. The model tests again demonstrated minimal interference of the fuselage augmentor on aerodynamic lift. A flapped canard surface also showed negligible influence on the performance of the wing and of the fuselage augmentor.
Effect of blades number to performance of Savonius water turbine in water pipe
NASA Astrophysics Data System (ADS)
Hamzah, Imron; Prasetyo, Ari; Tjahjana, D. D. D. Prija; Hadi, Syamsul
2018-02-01
Savonius is usually known as a wind turbine that works efficiently at low wind speed. In this research, the Savonius turbine is proposed for a pico hydro power plant that is installed straightly on the 3-inch vertical pipeline of rainwater and household waste. The Savonius water turbine was designed with blade curvature angle of 70°, the aspect ratio of 1, turbine diameter of 82 mm, and endplate ratio of 1,1. The experimental study investigated the effect of blades number to the performance of Savonius turbine on various volume flow rate of water. Savonius turbine with three blades number generated the highest coefficient of performance of 0.23 on tip speed ratio of 1.7 compared to turbines with the number of other blades.
Drug interactions with neuromuscular blockers.
Feldman, S; Karalliedde, L
1996-10-01
Drugs administered to patients undergoing anaesthesia may complicate the use of the neuromuscular blockers that are given to provide good surgical conditions. The various sites of interaction include actions on motor nerve conduction and spinal reflexes, acetylcholine (ACh) synthesis, mobilisation and release, sensitivity of the motor end plate to ACh and the ease of propagation of the motor action potential. In addition, many drugs affect the pharmacokinetics of neuromuscular blockers, especially as most drugs depend to a greater or lesser extent upon renal excretion. The clinically significant interaction between nondepolarisers and depolarisers may be due to blockade of the pre-synaptic nicotinic receptors by the depolarisers, leading to decreased ACh mobilisation and release. Synergism between nondepolarisers probably results from post-synaptic receptor mechanisms. Volatile anaesthetic agents affect the sensitivity of the motor end-plate (post-synaptic receptor blockade) in addition to having effects on pre-synaptic nicotinic function. The effects of nondepolarisers are likely to be potentiated and their action prolonged by large doses of local anaesthetics due to depression of nerve conduction, depression of ACh formation, mobilisation and release, decreases in post-synaptic receptor channel opening times and reductions in muscular contraction. Most antibacterials have effects on pre-synaptic mechanisms. Procainamide and quinidine principally block nicotinic receptor channels. Magnesium has a marked inhibitory effect on ACh release. Calcium antagonists could theoretically interfere with neurotransmitter release and muscle contractility. Phenytoin and lithium decrease ACh release, whilst corticosteroids and furosemide (frusemide) tend to increase the release of the transmitter. Ecothiopate, tacrine, organophosphates, propanidid, metoclopramide and bambuterol depress cholinesterase activity and prolong the duration of the neuromuscular block. The probability of clinically significant interactions increases in patients receiving several drugs with possible effects on neuromuscular transmission and muscle contraction.
LRP4 is critical for neuromuscular junction maintenance.
Barik, Arnab; Lu, Yisheng; Sathyamurthy, Anupama; Bowman, Andrew; Shen, Chengyong; Li, Lei; Xiong, Wen-cheng; Mei, Lin
2014-10-15
The neuromuscular junction (NMJ) is a synapse between motor neurons and skeletal muscle fibers, and is critical for control of muscle contraction. Its formation requires neuronal agrin that acts by binding to LRP4 to stimulate MuSK. Mutations have been identified in agrin, MuSK, and LRP4 in patients with congenital myasthenic syndrome, and patients with myasthenia gravis develop antibodies against agrin, LRP4, and MuSK. However, it remains unclear whether the agrin signaling pathway is critical for NMJ maintenance because null mutation of any of the three genes is perinatal lethal. In this study, we generated imKO mice, a mutant strain whose LRP4 gene can be deleted in muscles by doxycycline (Dox) treatment. Ablation of the LRP4 gene in adult muscle enabled studies of its role in NMJ maintenance. We demonstrate that Dox treatment of P30 mice reduced muscle strength and compound muscle action potentials. AChR clusters became fragmented with diminished junctional folds and synaptic vesicles. The amplitude and frequency of miniature endplate potentials were reduced, indicating impaired neuromuscular transmission and providing cellular mechanisms of adult LRP4 deficiency. We showed that LRP4 ablation led to the loss of synaptic agrin and the 90 kDa fragments, which occurred ahead of other prejunctional and postjunctional components, suggesting that LRP4 may regulate the stability of synaptic agrin. These observations demonstrate that LRP4 is essential for maintaining the structural and functional integrity of the NMJ and that loss of muscle LRP4 in adulthood alone is sufficient to cause myasthenic symptoms. Copyright © 2014 the authors 0270-6474/14/3413892-14$15.00/0.
Fan, Yuanjie; Yin, Yuehong
2013-12-01
Although exoskeletons have received enormous attention and have been widely used in gait training and walking assistance in recent years, few reports addressed their application during early poststroke rehabilitation. This paper presents a healthcare technology for active and progressive early rehabilitation using multisource information fusion from surface electromyography and force-position extended physiological proprioception. The active-compliance control based on interaction force between patient and exoskeleton is applied to accelerate the recovery of the neuromuscular function, whereby progressive treatment through timely evaluation contributes to an effective and appropriate physical rehabilitation. Moreover, a clinic-oriented rehabilitation system, wherein a lower extremity exoskeleton with active compliance is mounted on a standing bed, is designed to ensure comfortable and secure rehabilitation according to the structure and control requirements. Preliminary experiments and clinical trial demonstrate valuable information on the feasibility, safety, and effectiveness of the progressive exoskeleton-assisted training.
Isolated drops from capillary jets by means of Gaussian wave packets
NASA Astrophysics Data System (ADS)
Garcia, Francisco Javier; Gonzalez, Heliodoro; Castrejon-Pita, Alfonso Arturo; Castrejon-Pita, Jose Rafael; Gomez-Aguilar, Francisco Jose
2017-11-01
The possibility of obtaining isolated drops from a continuous liquid jet through localized velocity perturbations is explored analytically, numerically and experimentally. We show that Gaussian wave packets are appropriate for this goal. A temporal linear analysis predicts the early evolution of these wave packets and provides an estimate of the breakup length of the jet. Non-linear numerical simulations allow us both to corroborate these results and to obtain the shape of the surface of the jet prior to breakup. Finally, we show experimental evidence that stimulating with a Gaussian wave packet can lead to the formation of an isolated drop without disturbing the rest of the jet. The authors acknowledge support from the Spanish Government under Contract No. FIS2014-25161, the Junta de Andalucia under Contract No. P11-FQM-7919, the EPSRC-UK via the Grant EP/P024173/1, and the Royal Society.
Self-management for bronchiectasis.
Kelly, Carol; Grundy, Seamus; Lynes, Dave; Evans, David Jw; Gudur, Sharada; Milan, Stephen J; Spencer, Sally
2018-02-07
Bronchiectasis is a long term respiratory condition with an increasing rate of diagnosis. It is associated with persistent symptoms, repeated infective exacerbations, and reduced quality of life, imposing a burden on individuals and healthcare systems. The main aims of therapeutic management are to reduce exacerbations and improve quality of life. Self-management interventions are potentially important for empowering people with bronchiectasis to manage their condition more effectively and to seek care in a timely manner. Self-management interventions are beneficial in the management of other airways diseases such as asthma and COPD (chronic obstructive pulmonary disease) and have been identified as a research priority for bronchiectasis. To assess the efficacy, cost-effectiveness and adverse effects of self-management interventions for adults and children with non-cystic fibrosis bronchiectasis. We searched the Cochrane Airways Specialised Register of trials, clinical trials registers, reference lists of included studies and review articles, and relevant manufacturers' websites up to 13 December 2017. We included all randomised controlled trials of any duration that included adults or children with a diagnosis of non-cystic fibrosis bronchiectasis assessing self-management interventions delivered in any form. Self-management interventions included at least two of the following elements: patient education, airway clearance techniques, adherence to medication, exercise (including pulmonary rehabilitation) and action plans. Two review authors independently screened searches, extracted study characteristics and outcome data and assessed risk of bias for each included study. Primary outcomes were, health-related quality of life, exacerbation frequency and serious adverse events. Secondary outcomes were the number of participants admitted to hospital on at least one occasion, lung function, symptoms, self-efficacy and economic costs. We used a random effects model for analyses and standard Cochrane methods throughout. Two studies with a total of 84 participants were included: a 12-month RCT of early rehabilitation in adults of mean age 72 years conducted in two centres in England (UK) and a six-month proof-of-concept RCT of an expert patient programme (EPP) in adults of mean age 60 years in a single regional respiratory centre in Northern Ireland (UK). The EPP was delivered in group format once a week for eight weeks using standardised EPP materials plus disease-specific education including airway clearance techniques, dealing with symptoms, exacerbations, health promotion and available support. We did not find any studies that included children. Data aggregation was not possible and findings are reported narratively in the review.For the primary outcomes, both studies reported health-related quality of life, as measured by the St George's Respiratory Questionnaire (SGRQ), but there was no clear evidence of benefit. In one study, the mean SGRQ total scores were not significantly different at 6 weeks', 3 months' and 12 months' follow-up (12 months mean difference (MD) -10.27, 95% confidence interval (CI) -45.15 to 24.61). In the second study there were no significant differences in SGRQ. Total scores were not significantly different between groups (six months, MD 3.20, 95% CI -6.64 to 13.04). We judged the evidence for this outcome as low or very low. Neither of the included studies reported data on exacerbations requiring antibiotics. For serious adverse events, one study reported more deaths in the intervention group compared to the control group, (intervention: 4 of 8, control: 2 of 12), though interpretation is limited by the low event rate and the small number of participants in each group.For our secondary outcomes, there was no evidence of benefit in terms of frequency of hospital admissions or FEV1 L, based on very low-quality evidence. One study reported self-efficacy using the Chronic Disease Self-Efficacy scale, which comprises 10 components. All scales showed significant benefit from the intervention but effects were only sustained to study endpoint on the Managing Depression scale. Further details are reported in the main review. Based on overall study quality, we judged this evidence as low quality. Neither study reported data on respiratory symptoms, economic costs or adverse events. There is insufficient evidence to determine whether self-management interventions benefit people with bronchiectasis. In the absence of high-quality evidence it is advisable that practitioners adhere to current international guidelines that advocate self-management for people with bronchiectasis.Future studies should aim to clearly define and justify the specific nature of self-management, measure clinically important outcomes and include children as well as adults.
Karppinen, Jaro; Sorensen, Joan S.; Niinimäki, Jaakko; Leboeuf-Yde, Charlotte
2008-01-01
The prevalence of “vertebral endplate signal changes” (VESC) and its association with low back pain (LBP) varies greatly between studies. This wide range in reported prevalence rates and associations with LBP could be explained by differences in the definitions of VESC, LBP, or study sample. The objectives of this systematic critical review were to investigate the current literature in relation to the prevalence of VESC (including Modic changes) and the association with non-specific low back pain (LBP). The MEDLINE, EMBASE, and SveMED databases were searched for the period 1984 to November 2007. Included were the articles that reported the prevalence of VESC in non-LBP, general, working, and clinical populations. Included were also articles that investigated the association between VESC and LBP. Articles on specific LBP conditions were excluded. A checklist including items related to the research questions and overall quality of the articles was used for data collection and quality assessment. The reported prevalence rates were studied in relation to mean age, gender, study sample, year of publication, country of study, and quality score. To estimate the association between VESC and LBP, 2 × 2 tables were created to calculate the exact odds ratio (OR) with 95% confidence intervals. Eighty-two study samples from 77 original articles were identified and included in the analysis. The median of the reported prevalence rates for any type of VESC was 43% in patients with non-specific LBP and/or sciatica and 6% in non-clinical populations. The prevalence was positively associated with age and was negatively associated with the overall quality of the studies. A positive association between VESC and non-specific LBP was found in seven of ten studies from the general, working, and clinical populations with ORs from 2.0 to 19.9. This systematic review shows that VESC is a common MRI-finding in patients with non-specific LBP and is associated with pain. However, it should be noted that VESC may be present in individuals without LBP. PMID:18787845
NASA Astrophysics Data System (ADS)
Niedośpiał, Marcin; Knauff, Michał; Barcewicz, Wioleta
2015-03-01
In this paper results of the experimental tests of four full-scale composite steel-concrete elements are reported. In the steel-concrete composite elements, a steel beam was connected with a slab cast on profiled sheeting, by shear studs. The end-plates were (the thickness of 8 mm, 10 mm and 12 mm) thinner than in ordinary design. Joints between the column and the beams have been designed as semi-rigid, i.e. the deformations of endplates affect the distribution of forces in the adjacent parts of the slab. The paper presents the theory of cracking in reinforced concrete and steel-concrete composite members (according to the codes), view of crack pattern on the surface of the slabs and a comparison of the tests results and the code calculations. It was observed, that some factors influencing on crack widths are not taken in Eurocode 4 (which is based on Eurocode 2 with taking into account the phenomenon called "tension stiffening"). W artykule przedstawiono wyniki badań czterech elementów zespolonych. Kształtownik stalowy połączony był z betonowym stropem wykonanym na blasze fałdowej. W modelu zastosowano cienkie blachy czołowe (o grubości 8 mm, 10 mm i 12 mm), cieńsze niż zwykle przyjmowane w praktyce projektowej. Połączenie to zaprojektowano jako podatne tzn. takie, w którym odkształcenia blach czołowych mają istotny wpływ na rozkład sił w połączeniu. Przedstawiono normową teorię dotyczącą zarysowania elementów żelbetowych i zespolonych, obraz zarysowania stropu oraz porównano otrzymane wyniki z obliczeniami wykonanymi wg aktualnych norm. Zauważono, iż nie wszystkie czynniki obliczania szerokości rys w konstrukcjach zespolonych są zdefiniowane w normie projektowania konstrukcji zespolonych (która w tej kwestii odwołuje się do normy projektowania konstrukcji żelbetowych z uwzględnieniem zjawiska "tension stiffening").