bluuebunny/crossref_metadata_2025 huggingface dataset:
Individual Premotor Drive Pulses, Not Time-Varying Synergies, Are the Units of Adjustment for Limb Trajectories Constructed in Spinal Cord
Authors: Kargo William J. , Giszter Simon F.
Published: March 2008

Complex actions may arise by combining simple motor primitives. Our studies support individual premotor drive pulses or bursts as execution primitives in spinal cord. Alternatively, the fundamental execution primitives at the segmental level could be time-varying synergies. To distinguish these hypotheses, we examined sensory feedback effects during targeted wiping organized in spinal cord. This behavior comprises three bursts. We tested (1) whether feedback altered the structure of individual premotor drive bursts or primitives, and (2) whether feedback differentially modulated different drive bursts or pulses in the three burst sequence. At least two of the three bursts would need to always be comodulated to support a time-varying synergy. We used selective muscle vibration to control spindle feedback from a single muscle (biceps/iliofibularis). The structures of premotor drive bursts were conserved. However, biceps vibration (1) scaled the amplitudes of two bursts coactivated during the initial phase of wiping independently of one another without altering their phase, and (2) independently phase regulated the third burst but preserved its amplitude. Thus, all three bursts were regulated separately. Durations were unaffected. The independent effects depended on (1) time of vibration during wiping, (2) frequency of vibration, and (3) limb configuration. Because each of the three bursts was independently modulated, these data strongly support execution using individual premotor bursts rather than time-varying synergies at the spinal level of motor organization. Our data show that both sensory feedback and central systems of the spinal cord act in concert to adjust the individual premotor bursts in support of the straight and unimodal wiping trajectory.
Specificity of Speech Motor Learning
Authors: Tremblay Stéphanie , Houle Guillaume , Ostry David J.
Published: March 2008

The idea that the brain controls movement using a neural representation of limb dynamics has been a dominant hypothesis in motor control research for well over a decade. Speech movements offer an unusual opportunity to test this proposal by means of an examination of transfer of learning between utterances that are to varying degrees matched on kinematics. If speech learning results in a generalizable dynamics representation, then, at the least, learning should transfer when similar movements are embedded in phonetically distinct utterances. We tested this idea using three different pairs of training and transfer utterances that substantially overlap kinematically. We find that, with these stimuli, speech learning is highly contextually sensitive and fails to transfer even to utterances that involve very similar movements. Speech learning appears to be extremely local, and the specificity of learning is incompatible with the idea that speech control involves a generalized dynamics representation.
PKC-Induced Intracellular Trafficking of CaV2 Precedes Its Rapid Recruitment to the Plasma Membrane
Authors: Zhang Yalan , Helm Jessica S. , Senatore Adriano , Spafford J. David , Kaczmarek Leonard K. , Jonas Elizabeth A.
Published: March 2008

Activation of protein kinase C (PKC) potentiates secretion inAplysiapeptidergic neurons, in part by inducing new sites for peptide release at growth cone terminals. The mechanisms by which ion channels are trafficked to such sites are, however, not well understood. We now show that PKC activation rapidly recruits new CaV2 subunits to the plasma membrane, and that recruitment is blocked by latrunculin B, an inhibitor of actin polymerization. In contrast, inhibition of microtubule polymerization selectively prevents the appearance of CaV2 subunits only at the distal edge of the growth cone. In resting neurons, CaV2-containing organelles reside in the central region of growth cones, but are absent from distal lamellipodia. After activation of PKC, these organelles are transported on microtubules to the lamellipodium. The ability to traffic to the most distal sites of channel insertion inside the lamellipodium does, therefore, not require intact actin but requires intact microtubules. Only after activation of PKC do CaV2 channels associate with actin and undergo insertion into the plasma membrane.
Neural Dissociation between Visual Awareness and Spatial Attention
Authors: Wyart Valentin , Tallon-Baudry Catherine
Published: March 2008

To what extent does what we consciously see depend on where we attend to? Psychologists have long stressed the tight relationship between visual awareness and spatial attention at the behavioral level. However, the amount of overlap between their neural correlates remains a matter of debate. We recorded magnetoencephalographic signals while human subjects attended toward or away from faint stimuli that were reported as consciously seen only half of the time. Visually identical stimuli could thus be attended or not and consciously seen or not. Although attended stimuli were consciously seen slightly more often than unattended ones, the factorial analysis of stimulus-induced oscillatory brain activity revealed distinct and independent neural correlates of visual awareness and spatial attention at different frequencies in the gamma range (30–150 Hz). Whether attended or not, consciously seen stimuli induced increased mid-frequency gamma-band activity over the contralateral visual cortex, whereas spatial attention modulated high-frequency gamma-band activity in response to both consciously seen and unseen stimuli. A parametric analysis of the data at the single-trial level confirmed that the awareness-related mid-frequency activity drove the seen–unseen decision but also revealed a small influence of the attention-related high-frequency activity on the decision. These results suggest that subjective visual experience is shaped by the cumulative contribution of two processes operating independently at the neural level, one reflecting visual awareness per se and the other reflecting spatial attention.
Effector Immediate-Early Gene Arc in the Amygdala Plays a Critical Role in Alcoholism
Authors: Pandey Subhash C. , Zhang Huaibo , Ugale Rajesh , Prakash Anand , Xu Tiejun , Misra Kaushik
Published: March 2008

The immediate early gene, activity-regulated cytoskeleton-associated protein (Arc), has been implicated in synaptic plasticity. However, the role of Arc in alcoholism is unknown. Here, we report that the anxiolytic effects of acute ethanol were associated with increased brain-derived neurotrophic factor (BDNF) and tyrosine kinase B (trkB) expression, increased phosphorylation of extracellular signal-regulated kinases 1/2 (Erk1/2), Elk-1, and cAMP responsive element-binding protein (CREB), increased Arc expression, and increased dendritic spine density (DSD) in both the central amygdala (CeA) and medial amygdala (MeA) but not in the basolateral amygdala (BLA) of rats. Conversely, the anxiogenic effects of withdrawal after long-term ethanol exposure were associated with decreased BDNF and trkB expression, decreased phosphorylation of Erk1/2, Elk-1, and CREB, decreased Arc expression, and decreased DSD in both the CeA and MeA but not in the BLA of rats. We also showed that BDNF infusion into the CeA normalized phosphorylation of Erk1/2, Elk-1, and CREB, and normalized Arc expression, thereby protecting against the onset of ethanol withdrawal-related anxiety. We further demonstrated that arresting Arc expression in the CeA decreased DSD, thereby increasing anxiety-like and alcohol-drinking behaviors in control rats. These results revealed that BDNF–Arc signaling and the associated DSD in the CeA, and possibly in the MeA, may be involved in the molecular processes of alcohol dependence and comorbidity of anxiety and alcohol-drinking behaviors.
A Vicious Cycle Involving Release of Heat Shock Protein 60 from Injured Cells and Activation of Toll-Like Receptor 4 Mediates Neurodegeneration in the CNS
Authors: Lehnardt Seija , Schott Eckart , Trimbuch Thorsten , Laubisch Dinah , Krueger Christina , Wulczyn Gregory , Nitsch Robert , Weber Joerg R.
Published: March 2008

Infection, ischemia, trauma, and neoplasia elicit a similar inflammatory response in the CNS characterized by activation of microglia, the resident CNS monocyte. The molecular events leading from CNS injury to the activation of innate immunity is not well understood. We show here that the intracellular chaperone heat shock protein 60 (HSP60) serves as a signal of CNS injury by activating microglia through a toll-like receptor 4 (TLR4)-dependent and myeloid differentiation factor 88 (MyD88)-dependent pathway. HSP60 is released from CNS cells undergoing necrotic or apoptotic cell death and specifically binds to microglia. HSP60-induced synthesis of neurotoxic nitric oxide by microglia is dependent on TLR4. HSP60 induces extensive axonal loss and neuronal death in CNS cultures from wild-type but not TLR4 or MyD88 loss-of-function mutant mice. This is the first evidence of an endogenous molecular pathway common to many forms of neuronal injury that bidirectionally links CNS inflammation with neurodegeneration.
Extinction of a Classically Conditioned Response: Red Nucleus and Interpositus
Authors: Robleto Karla , Thompson Richard F.
Published: March 2008

It is well established that the cerebellum and its associated circuitry are essential for classical conditioning of the eyeblink response and other discrete motor responses (e.g., limb flexion, head turn, etc.) learned with an aversive unconditioned stimulus. However, brain mechanisms underlying extinction of these responses are still relatively unclear. Behavioral studies have demonstrated extinction to be an active learning process distinct from acquisition. Accordingly, this current understanding of extinction has guided neural studies that have tried to identify possible brain structures that could support this new learning. However, whether extinction engages the same brain sites necessary for acquisition is not yet clear. This poses an overriding problem for understanding brain mechanisms necessary for extinction because such analysis cannot be done without first identifying brain sites and pathways involved in this phenomenon. Equally elusive is the validity of a behavioral theory of extinction that can account for the properties of extinction. In this study, we looked at the involvement of the interpositus and the red nucleus in extinction. Results show that, although inactivation of both nuclei blocks response expression, only inactivation of the interpositus has a detrimental effect on extinction. Moreover, this detrimental effect was completely removed when inactivation of the interpositus was paired with electrical stimulation of the red nucleus. These findings speak to the important role of cerebellar structures in the extinction of discrete motor responses and provide important insight as to the validity of a particular theory of extinction.
Transient D1Dopamine Receptor Expression on Prefrontal Cortex Projection Neurons: Relationship to Enhanced Motivational Salience of Drug Cues in Adolescence
Authors: Brenhouse Heather C. , Sonntag Kai C. , Andersen Susan L.
Published: March 2008

Adolescence is a transitional period during development that is associated with a greater likelihood of addiction to drugs than any other age. In the prefrontal cortex (PFC), D1dopamine receptors mediate motivational salience attribution, which plays a role in addiction. Here, we investigated the relationship of age-related D1dopamine receptor expression in the PFC with the maturation of cocaine place conditioning. Confocal microscopy revealed that retrogradely traced cortical output neurons to the nucleus accumbens express higher levels of D1receptors during adolescence compared with younger and older ages. D1expression does not change on GABAergic interneurons across age. Adolescent differences in D1expression occur independently of cortical-accumbens connectivity, which proliferates through adulthood. Behaviorally, adolescent rats are more sensitive to cocaine place conditioning than younger and older rats. However, microinjections of the D1antagonist SCH23390 into the PFC blocked adolescent place preferences, whereas microinjections of D1agonists dose-dependently increased preferences for cocaine-associated environments previously not preferred by juveniles. These results suggest that the heightened expression of D1receptors on cortical-accumbens projections may help explain increased sensitivity to environmental events and addictive behaviors during adolescence, whereas the paucity of D1-expressing projections may reduce risk in juveniles.
Cholinergic Deafferentation of Prefrontal Cortex Increases Sensitivity to Cross-Modal Distractors during a Sustained Attention Task
Authors: Newman Lori A. , McGaughy Jill
Published: March 2008

The effects of restricted cholinergic deafferentation of prefrontal cortex in rats on sustained attention were assessed. Attentional demands were increased by presentation of distractor stimuli in a different modality (auditory) or the same modality (visual) as target stimuli. Additionally, the effects of the regularity of the distractor on rats' ability to disregard this stimulus were assessed by testing different frequencies of stimuli for each modality. Cholinergically lesioned rats were more sensitive to the effects of auditory distractors than nonlesioned rats, whereas visual distractors of any frequency potently impaired the performance of all subjects. The effects of the auditory stimuli on attentional performance varied depending on the frequency of the tone. A tone with a predictable pattern enhanced signal detection in all rats. An irregular tone selectively impaired performance of rats with cholinergic lesions. Additional tests suggest that rats use the regular tone to time when to attend. Lesioned rats were impaired when the regular tone was presented with a more variable intertrial interval in a subsequent testing session, suggesting impairments in top-down control. In addition to changes in top-down control of attention, differential effects on performance based on the regularity of the tone suggest that stimulus properties encoded by bottom-up processes are also altered after lesioning. The current data suggest that cholinergic deafferentation of prefrontal cortex alters top-down and bottom-up processing of stimuli.
Timing Neurogenesis and Differentiation: Insights from Quantitative Clonal Analyses of Cerebellar Granule Cells
Authors: Espinosa J. Sebastian , Luo Liqun
Published: March 2008

The cerebellum is an excellent model system to study how developmental programs give rise to exquisite neuronal circuits in the adult brain. Here, we describe our findings regarding granule cell neurogenesis and differentiation using the MADM method (mosaic analysis with double markers) in mice. By following the development of individual granule cell clones, we show that (1) granule cell precursors (GCPs) undergo predominantly symmetric division during postnatal development; (2) clonally related granule cells (GCs) exit the cell cycle within a narrow time window and stack their axons in the molecular layer in chronological order from deep to superficial sublayers; and (3) whereas the average GCP proliferation in the external granular layer is progressively slower as development proceeds, there is a rapid expansion of GCPs shortly before clonally related GCs exit the cell cycle. These properties produce GC clones that are distinct, each having a restricted axonal projection, but that are on average similar in cell number. We discuss possible developmental mechanisms and functional implications of these findings.
Interplay between Cyclin-Dependent Kinase 5 and Glycogen Synthase Kinase 3β Mediated by Neuregulin Signaling Leads to Differential Effects on Tau Phosphorylation and Amyloid Precursor Protein Processing
Authors: Wen Yi , Planel Emmanuel , Herman Mathieu , Figueroa Helen Y. , Wang Lili , Liu Li , Lau Lit-Fui , Yu Wai Haung , Duff Karen E.
Published: March 2008

Cyclin-dependent kinase 5 (cdk5) and glycogen synthase kinase 3β (GSK3β) have been implicated in pathogenic processes associated with Alzheimer's disease because both kinases regulate tau hyperphosphorylation and enhance amyloid precursor protein (APP) processing leading to an increase in amyloid β (Aβ) production. Here we show that young p25 overexpressing mice have enhanced cdk5 activity but reduced GSK3β activity attributable to phosphorylation at the inhibitory GSK3β–serine 9 (GSK3β–S9) site. Phosphorylation at this site was mediated by enhanced activity of the neuregulin receptor complex, ErbB, and activation of the downstream phosphatidylinositol 3 kinase/Akt pathway. Young p25 mice had elevated Aβ peptide levels, but phospho-tau levels were decreased overall. Thus, cdk5 appears to play a dominant role in the regulation of amyloidogenic APP processing, whereas GSK3β plays a dominant role in overall tau phosphorylation. In older mice, GSK3β inhibitory phosphorylation at S9 was reduced relative to young mice. Aβ peptide levels were still elevated but phospho-tau levels were either unchanged or showed a trend to increase, suggesting that GSK3β activity increases with aging. Inhibition of cdk5 by a specific inhibitor reduced cdk5 activity in p25 mice, leading to reduced Aβ production in both young and old mice. However, in young mice, cdk5 inhibition reversed GSK3β inhibition, leading to an increase in overall tau phosphorylation. When cdk5 inhibitor was administered to very old, nontransgenic mice, inhibition of cdk5 reduced Aβ levels, and phospho-tau levels showed a trend to increase. Thus, cdk5 inhibitors may not be effective in targeting tau phosphorylation in the elderly.
Transient Receptor Potential A1 Is a Sensory Receptor for Multiple Products of Oxidative Stress
Authors: Andersson David A. , Gentry Clive , Moss Sian , Bevan Stuart
Published: March 2008

Transient receptor potential A1 (TRPA1) is expressed in a subset of nociceptive sensory neurons where it acts as a sensor for environmental irritants, including acrolein, and some pungent plant ingredients such as allyl isothiocyanate and cinnamaldehyde. These exogenous compounds activate TRPA1 by covalent modification of cysteine residues. We have used electrophysiological methods and measurements of intracellular calcium concentration ([Ca2+]i) to show that TRPA1 is activated by several classes of endogenous thiol-reactive molecules. TRPA1 was activated by hydrogen peroxide (H2O2; EC50, 230 μm), by endogenously occurring alkenyl aldehydes (EC50: 4-hydroxynonenal 19.9 μm, 4-oxo-nonenal 1.9 μm, 4-hydroxyhexenal 38.9 μm) and by the cyclopentenone prostaglandin, 15-deoxy-Δ12,14-prostaglandin J2(15d-PGJ2, EC50: 5.6 μm). The effect of H2O2was reversed by treatment with dithiothreitol indicating that H2O2acts by promoting the formation of disulfide bonds whereas the actions of the alkenyl aldehydes and 15d-PGJ2were not reversed, suggesting that these agents form Michael adducts. H2O2and the naturally occurring alkenyl aldehydes and 15d-PGJ2acted on a subset of isolated rat and mouse sensory neurons [∼25% of rat dorsal root ganglion (DRG) and ∼50% of nodose ganglion neurons] to evoke a depolarizing inward current and an increase in [Ca2+]iin TRPA1 expressing neurons. The abilities of H2O2, alkenyl aldehydes and 15d-PGJ2to raise [Ca2+]iin mouse DRG neurons were greatly reduced in neurons fromtrpa1−/−mice. Furthermore, intraplantar injection of either H2O2or 15d-PGJ2 evoked a nocifensive/pain response in wild-type mice, but not intrpa1−/−mice. These data demonstrate that multiple agents produced during episodes of oxidative stress can activate TRPA1 expressed in sensory neurons.
Action Potential-Independent and Nicotinic Receptor-Mediated Concerted Release of Multiple Quanta at Hippocampal CA3–Mossy Fiber Synapses
Authors: Sharma Geeta , Grybko Michael , Vijayaraghavan Sukumar
Published: March 2008

Presynaptic action potential-independent transmitter release is a potential means of information transfer across synapses. We show that in the hippocampal mossy fiber boutons, activation of the α7-subtype of nicotinic acetylcholine receptors (α7-nAChRs) results in a large increase in the amplitude of spontaneous events, resulting from concerted release of multiple quanta from the mossy fiber boutons. This amplitude increase is abolished at low temperatures. Activation of α7-nAChRs causes a rise in intraterminal calcium at mossy fiber boutons, involving ryanodine receptors. Regulation of concerted release requires the subsequent activation of presynaptic calcium/calmodulin-dependent protein kinase II (CaMKII). Activation of CaMKII is required to drive presynaptic action potential-independent transmission at the mossy fiber–CA3 pyramidal cell synapse. The effects of α7-nAChR activation are mediated by biologically relevant doses of nicotine. Our results demonstrate a novel form of synaptic plasticity mediated by presynaptic α7-nAChRs and store calcium that is temporally different and might respond to a different history of synaptic activity than that mediated by incoming action potentials.
Synergistic Neuroprotective Effects of Lithium and Valproic Acid or Other Histone Deacetylase Inhibitors in Neurons: Roles of Glycogen Synthase Kinase-3 Inhibition
Authors: Leng Yan , Liang Min-Huei , Ren Ming , Marinova Zoya , Leeds Peter , Chuang De-Maw
Published: March 2008

Lithium and valproic acid (VPA) are two primary drugs used to treat bipolar mood disorder and have frequently been used in combination to treat bipolar patients resistant to monotherapy with either drug. Lithium, a glycogen synthase kinase-3 (GSK-3) inhibitor, and VPA, a histone deacetylase (HDAC) inhibitor, have neuroprotective effects. The present study was undertaken to demonstrate synergistic neuroprotective effects when both drugs were coadministered. Pretreatment of aging cerebellar granule cells with lithium or VPA alone provided little or no neuroprotection against glutamate-induced cell death. However, copresence of both drugs resulted in complete blockade of glutamate excitotoxicity. Combined treatment with lithium and VPA potentiated serine phosphorylation of GSK-3 α and β isoforms and inhibition of GSK-3 enzyme activity. Transfection with GSK-3α small interfering RNA (siRNA) and/or GSK-3β siRNA mimicked the ability of lithium to induce synergistic protection with VPA. HDAC1 siRNA or other HDAC inhibitors (phenylbutyrate, sodium butyrate or trichostatin A) also caused synergistic neuroprotection together with lithium. Moreover, combination of lithium and HDAC inhibitors potentiated β-catenin-dependent, Lef/Tcf-mediated transcriptional activity. An additive increase in GSK-3 serine phosphorylation was also observed in mice chronically treated with lithium and VPA. Together, for the first time, our results demonstrate synergistic neuroprotective effects of lithium and HDAC inhibitors and suggest that GSK-3 inhibition is a likely molecular target for the synergistic neuroprotection. Our results may have implications for the combined use of lithium and VPA in treating bipolar disorder. Additionally, combined use of both drugs may be warranted for clinical trials to treat glutamate-related neurodegenerative diseases.
A Hierarchy of Temporal Receptive Windows in Human Cortex
Authors: Hasson Uri , Yang Eunice , Vallines Ignacio , Heeger David J. , Rubin Nava
Published: March 2008

Real-world events unfold at different time scales and, therefore, cognitive and neuronal processes must likewise occur at different time scales. We present a novel procedure that identifies brain regions responsive to sensory information accumulated over different time scales. We measured functional magnetic resonance imaging activity while observers viewed silent films presented forward, backward, or piecewise-scrambled in time. Early visual areas (e.g., primary visual cortex and the motion-sensitive area MT+) exhibited high response reliability regardless of disruptions in temporal structure. In contrast, the reliability of responses in several higher brain areas, including the superior temporal sulcus (STS), precuneus, posterior lateral sulcus (LS), temporal parietal junction (TPJ), and frontal eye field (FEF), was affected by information accumulated over longer time scales. These regions showed highly reproducible responses for repeated forward, but not for backward or piecewise-scrambled presentations. Moreover, these regions exhibited marked differences in temporal characteristics, with LS, TPJ, and FEF responses depending on information accumulated over longer durations (∼36 s) than STS and precuneus (∼12 s). We conclude that, similar to the known cortical hierarchy of spatial receptive fields, there is a hierarchy of progressively longer temporal receptive windows in the human brain.
Early Neuronal and Glial Fate Restriction of Embryonic Neural Stem Cells
Authors: Delaunay Delphine , Heydon Katharina , Cumano Ana , Schwab Markus H. , Thomas Jean-Léon , Suter Ueli , Nave Klaus-Armin , Zalc Bernard , Spassky Nathalie
Published: March 2008

The question of how neurons and glial cells are generated during the development of the CNS has over time led to two alternative models: either neuroepithelial cells are capable of giving rise to neurons first and to glial cells at a later stage (switching model), or they are intrinsically committed to generate one or the other (segregating model). Using the developing diencephalon as a model and by selecting a subpopulation of ventricular cells, we analyzed bothin vitro, using clonal analysis, andin vivo, using inducible Cre/loxP fate mapping, the fate of neuroepithelial and radial glial cells generated at different time points during embryonic development. We found that, during neurogenic periods [embryonic day 9.5 (E9.5) to 12.5], proteolipid protein (plp)-expressing cells were lineage-restricted neuronal precursors, but later in embryogenesis, during gliogenic periods (E13.5 to early postnatal),plp-expressing cells were lineage-restricted glial precursors. In addition, we show that glial cells forming at E13.5 arise from a new pool of neuroepithelial progenitors distinct from neuronal progenitors cells, which lends support to the segregating model.
Bötzinger Expiratory-Augmenting Neurons and the Parafacial Respiratory Group
Authors: Fortuna Michal G. , West Gavin H. , Stornetta Ruth L. , Guyenet Patrice G.
Published: March 2008

In neonatal rat brainsin vitro, the rostral ventral respiratory column (rVRC) contains neurons that burst just before the phrenic nerve discharge (PND) and rebound after inspiration (pre-I neurons). These neurons, called parafacial respiratory group (pfRG), have been interpreted as a master inspiratory oscillator, an expiratory rhythm generator or simply as neonatal precursors of retrotrapezoid (RTN) chemoreceptor neurons. pfRG neurons have not been identified in adults, and their phenotype is unknown. Here, we confirm that the rVRC normally lacks pre-I neurons in adult anesthetized rats. However, we show that, during hypercapnic hypoxia, a population of rVRC expiratory-augmenting (E-AUG) neurons consistently develops a pre-I discharge. These cells reside in the Bötzinger region of the rVRC, they express glycine-transporter-2, and their axons arborize throughout the VRC. Hypoxia triggers an identical pre-I pattern in retroambigual expiratory bulbospinal neurons, but this pattern is not elicited in Bötzinger expiratory-decrementing neurons, Bötzinger inspiratory neurons, RTN neurons, and blood pressure-regulating neurons. In conclusion, under hypoxiain vivo, abdominal expiratory premotor neurons of adult rats develop a pre-I pattern reminiscent of that observed in neonate brainstemsin vitro. In the rVRC of adult rats, pre-I cells include selected rhythmogenic neurons (glycinergic Bötzinger neurons) but not RTN chemoreceptors. We suggest that the pfRG may not be an independent rhythm generator but a heterogeneous collection of E-AUG neurons (glycinergic Bötzinger neurons, possibly facial motor and premotor neurons), the discharge of which becomes preinspiratory under specific experimental conditions resulting from, in part, a prolonged and intensified activity of postinspiratory neurons.
Superplastic deformation characteristics and constitution equation in rapidly solidified Mg–Al–Ga alloy
Authors: Uoya A. , Shibata T. , Higashi K. , Inoue A. , Masumoto T.
Published: March 2008

The hot deformation characteristics of a newly typed, high strength magnesium-based alloy, Mg–8.3 wt.% Al–8.1 wt.% Ga alloy, produced by rapidly solidified and powder metallurgy method have been investigated. Tensile tests were carried out at a temperature range from 523 to 623 K and a strain rate range from 10−4 to 1 s−1. Superplastic characteristics were found and, especially, a maximum elongation-to-failure of 1080% was obtained at 573 K and at a relatively high strain rate of 10−2 s−1. Because of the presence of fine microstructures at high temperatures, the optimum superplastic strain rate of the Mg–Al–Ga alloy was higher than that of the reported conventional superplastic aluminum and magnesium alloys.
Identification of voices in electronically disguised speech
Authors: Clark Jessica , Foulkes Paul
Published: March 2008

We describe an experiment on the effects of electronic vocal disguise on speaker identification. 36 listeners were trained to identify four voices. They then participated in listening tests in which their task was to identify speakers in a set of short stimuli. In the first test the stimuli were natural. For the second test the voices were artificially disguised. The fundamental frequency of the stimuli was modified using Sony SoundForge. As predicted, the rate of correct responses fell for the modified stimuli. The more extreme disguises (±8 semitones) yielded the lowest scores. The majority of listeners performed above chance level in all except the –8 semitone condition. The results showed significant effects for both listener and speaker, in line with previous studies of undisguised and naturally-disguised speaker identification. The variation suggests further research is required to assess the robustness of those forms of electronic disguise used to protect vulnerable witnesses.
The Jamaican Creole speaker in the UK justice system
Authors: Brown-Blake Celia Nadine , Chambers Paul
Published: March 2008

This article explores intelligibility between the Jamaican vernacular, an English-based lexicon Creole language, and English. It examines discourse in pre-trial interviews conducted by functionaries in the UK criminal justice system, usually police and customs officers and lawyers, with Jamaican Creole (JC)-dominant or monolingual speakers who are typically persons suspected or accused of offences or potential witnesses of offences. Using discourse analysis techniques, it highlights instances of miscommunication and lack of comprehension not only between the parties to the interview, but also on the part of the transcribers. The analysis attempts to trace the miscommunication and lack of understanding to linguistic distinctions between the two language varieties. The paper also explores the possible legal consequences of these language-related miscommunications or lack of communication. The analysis underscores the need for continuous interpretation during pre-trial interviews and for interpretation/translation services at the transcription stage despite some similarity between the two languages.
Much Suffering Eye in Antioch's House of the Evil Eye
Authors: Cousland J R C
Published: March 2008

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Spectacles of Gender
Authors: Juschka Darlene
Published: March 2008

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Without God or Law
Authors: Creechan James H , De la Herrán Garcia Jorge
Published: March 2008

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Pamela Barmash. Homicide in the Biblical World
Authors: Greenshields Malcolm
Published: March 2008

Pamela Barmash. Homicide in the Biblical World. xvi + 253 pages. Cambridge University Press, 2005. ISBN: 0-521-83468-6 $25.99.
On Concepts and ‘the Best Place’
Authors: Waugh Earle H , Roan Chief Wayne
Published: March 2008

This article attempts to place Cree conceptions of reality on the same footing as both Western and Chinese traditions; drawing upon both oral and written sources, especially that of ceremonialist Wayne Roan, the Cree case is made for a concept of ‘the best place’ for understanding something, implying that rational thought itself has to be ‘placed’ in order to come to any conclusions. This introduces a different dimension into discussions in relation to the other two traditions, both of which appear to construct reality without relation to either physical or metaphysical ‘place’. However, other aspects of Cree conceptions do not differ that greatly from the Chinese understanding of reality.
Realms of Discourse
Authors: Checkland David
Published: March 2008

Is there a distinct ‘realm’ of religious discourse? Do religious claims so conceived stand in potential conflict with other sorts of claims? Several ways of elucidating the idea of a ‘distinct realm’ are examined and found wanting. Then the work of DZ Phillips is sympathetically, but critically, examined for its implications for the idea of a distinct ‘realm’ of religious discourse.
Performance of Commercially Available Passive Integrated Transponder (PIT) Tag Systems Used for Fish Identification and Interjurisdictional Fisheries Management
Authors: Fuller S. Adam , Henne James P. , Seals John , Mudrak Vincent A.
Published: March 2008

Passive integrated transponder (PIT) tag systems are commonly used in identification and monitoring programs with fisheries applications. Transponders of different frequencies, sizes, and code formats are available from numerous manufacturers, and there is increasing concern regarding the need to coordinate tagging efforts with appropriate equipment. Given the high cost of PIT tag systems and the adverse management implications of using incompatible equipment, we evaluated the performance of 20 transponder models and 11 transceiver models currently used in the United States. Compatibility among transceivers ranged from 14% to 81% when evaluated with the 20 transponders in this study. The maximum read distance across all tags and tag readers averaged 9.5 cm (range, 2.0–31.3 cm), and there were significant differences among reader and tag type combinations. Both transponder size and frequency significantly affected the maximum read distance, but transceiver model choice appeared to allow for the greatest practical increase in read distance. These results should assist resource managers with decisions regarding the coordination of tagging efforts that use PIT tag systems, particularly those involving long-lived or interjurisdictional species.
Measuring the Length of a Pelagic Longline Set: Applications for Management
Authors: Kerstetter David W.
Published: March 2008

Recent U.S. federal fisheries management actions aimed at reducing bycatch have established or proposed limits on the length of a pelagic longline set. However, such management measures are unenforceable if the criteria for measuring the length of a pelagic longline set have not been defined. Differences in the physical gear and deployment strategies suggest high variability among the several methods that can be used to measure set length. This study uses a combination of scientifically monitored sets, fisheries observer data, and federal pelagic logbook data to compare four possible metrics of longline set length: the geographic track of the vessel while deploying the gear, a “folding ruler” approximation based on straight-line distance between ends of the sections of gear, the straight-line distance between the beginning and end of the gear, and a dead-reckoning distance based on vessel speed and the time duration of the gear deployment. Results indicate that while set lengths determined from self-reported data via logbook submissions are not significantly different from the other proposed methods, the inclusion of an ending location for each set within the logbook form could provide a basis for evaluation of the regulatory measure.
Behavioral Responses of Rainbow Smelt to in situ Strobe Lights
Authors: Hamel Martin J. , Brown Michael L. , Chipps Steven R.
Published: March 2008

We conducted in situ testing of strobe lights as a potential fish deterrent by examining avoidance and acclimation behaviors of rainbow smelt Osmerus mordax in Lake Oahe, South Dakota. Split-beam hydroacoustics were used to assess the effectiveness of the deterrent system by comparing proximal densities of rainbow smelt before and after the device was activated. In summer 2005, strobe lights successfully repelled rainbow smelt to a minimum horizontal distance of 21 m at both 1 h and 4 h postactivation; the model AGL-FH 920 flashhead produced a light intensity of 6,585 lumens per flash. Similarly in 2004, a model AGL-FH 901 flashhead, which produced a light intensity of 2,634 lumens per flash, repelled rainbow smelt to a horizontal distance of 15 m. A comparison of strata 10 m above and below the strobe light system showed that rainbow smelt were vertically displaced to approximately 6 m. We conclude that strobe lights elicit behavioral avoidance by rainbow smelt and may provide an effective means for reducing entrainment losses through Oahe Dam.
Seroprevalence of Toxoplasma gondii infection among indian people living in Iauareté, São Gabriel da Cachoeira, Amazonas, Brazil
Authors: Bóia Márcio Neves , Carvalho-Costa Filipe Anibal , Sodré Fernando Campos , Pinto Gloria Maria Trindade , Amendoeira Maria Regina Reis
Published: March 2008

The goal of this survey was to estimate the seroprevalence of Toxoplasma gondii infection in Iauareté, a multiethnic Indian community in the upper Rio Negro basin. We carried out a cross-sectional survey (n = 260), in order to obtain serum samples and demographic data. The sample was randomly selected, by family conglomerate analysis. Serodiagnosis was performed by an enzyme-linked immunosorbent assay and indirect immunofluorescence. Prevalence of reactivity was 73.5% (191/260), being higher in the older-age groups, reaching 95.7% (44/46) in the group aged 50 years or more. The majority of seropositive subjects had titers equal to or less than 1:64. Seroprevalence was greater in Indians belonging to the Hupda ethnic group (p = 0.03). According to the present survey, Indian people living in Iauareté have a high prevalence of antibodies to T. gondii. Demographic concentration and urbanization within low sanitation and poor hygiene backgrounds, as well as unfiltered water consumption, may be related to the high frequency of T. gondii seroprevalence observed in the studied area.
Physiological responses of pirarucu (Arapaima gigas) to acute handling stress
Authors: Gomes Levy de Carvalho
Published: March 2008

Pirarucu (Arapaima gigas) is an obligatory air-breathing fish from the Amazon basin. Previous study showed that pirarucu juveniles present a latency period in their response to moderate stress (transportation). Therefore the objective of this study was to verify the effects of a prolonged air exposure stress in lactate, glucose, cortisol, haematocrit, haemoglobin, and liver glycogen in pirarucu. Thirty-six fish were handled by netting and subjected to air exposure for 75-min. Six fish were sampled before handling and at 0, 6, 24, 48, and 96h after handling. Fish cortisol, lactate and haematocrit rose after handling, returning to previous unstressed values on the following sampling (6h after handling). Glucose increased significantly after handling and that was maintained for 24 h. There were no changes in haemoglobin and liver glycogen as a consequence of handling. The results demonstrate a quick response when exposed to an acute stressor and a fast recovery, suggesting that pirarucu does not use their glycogen reserves during an acute stress. The results suggest that pirarucu exhibit physiological stress responses to handling similar in magnitude to those previously documented for many teleostean fishes, including salmonids.
Estudo comparativo de alguns indicadores em municípios do Estado de São Paulo segundo a implantação do Saúde da Família
Authors: Cruz Mariângela Guanaes Bortolo da
Published: March 2008

Este estudo tem como objetivo descrever comparativamente o comportamento de três indicadores de saúde: mortalidade infantil; cobertura vacinal/taxa de abandono da vacina DPT e hospitalizações em menores de 5 anos, em dois Blocos de sete municípios paulistas, com características sócio-econômicas semelhantes, mas diferenciados por terem implantado (Bloco A) e não implantado (Bloco B) o Programa de Saúde da Família (PSF), sendo parâmetro para esta comparação os mesmos indicadores de saúde para o Estado de São Paulo. Utilizou-se do cálculo e da descrição dos indicadores para cada Bloco estudado, nos seguintes períodos: mortalidade infantil (triênio 1995-997 e 1998-2000), cobertura vacinal básica (de 1996 a 2000), taxa de abandono da vacina DPT (triênio 1998-2000) e hospitalizações em menores de cinco anos (triênio 1998-2000). Verificou-se que a implantação do PSF foi um dos fatores que contribuiu para a queda das taxas de mortalidade infantil e abandono da vacina DPT.
Cuidar de pessoa incapacitada por acidente vascular cerebral no domicílio: o fazer do cuidador familiar
Authors: Perlini Nara Marilene Oliveira Girardon , Faro Ana Cristina Mancussi e
Published: March 2008

Estudo exploratório, descritivo e quantitativo que busca identificar e descrever as atividades do familiar que cuida de pessoas incapacitadas por AVC no domicílio. A amostra constituiu-se de 35 cuidadores familiares, predominantemente mulheres, esposas ou filhas. Os cuidados realizados relacionam-se ao grau de incapacidade do familiar. As orientações recebidas denotam falta de compromisso dos profissionais com a continuidade do cuidado. O cuidador aprende a cuidar no cotidiano, com base na observação e auxílio à enfermagem na internação. As dificuldades pautam-se no esforço físico, na desinformação e no medo, no constrangimento e na vergonha em lidar com o corpo do outro. O estudo enfoca a necessidade do preparo para a alta hospitalar, salienta a família como espaço concreto para o cuidado; o aumento da expectativa de vida é uma constatação.
Niveles de nitrógeno y su fraccionamiento en el cultivo del gladiolo para suelos Ferralíticos Rojos
Authors: Hernández Díaz María Isabel , Marrero González Virginia , González Hurtado Mayra , Salgado Pulido Julia Mirta , Ojeda Velóz Anselma
Published: March 2008

El objetivo del presente estudio fue evaluar niveles crecientes de nitrógeno y momentos de aplicación del fertilizante nitrogenado en el cultivo del gladiolo. La experiencia se desarrolló en el Instituto de Investigaciones Hortícolas Liliana Dimitrova (Municipio de Quivicán, La Habana, Cuba), en un suelo Ferralítico Rojo, entre los meses de octubre y febrero de las campañas 2004/2005 y 2005/2006. Se evaluaron los componentes de la calidad de las espigas y del material de plantación, así como el efecto de los tratamientos en el estado nutricional de la planta y en la vida en anaquel de las espigas. No se observaron diferencias entre las dosis de nitrógeno y los momentos de aplicación del fertilizante en las variables de calidad de la espiga y del cormo. No obstante, con la variante 70 kg ha-1 de N, aplicada ½ en plantación y ½ a los 60 días posteriores, se logra un mayor porcentaje de espigas ubicadas en las categorías comerciales y un menor número de tallos florales de calidad inferior. En cuanto al estado nutricional de la plantación, existe una relación positiva entre los niveles y los contenidos foliares de nitrógeno aplicados.
Impacts of a liberalization in the USA market for Frozen Concentrated Orange Juice: why Florida's producers are so afraid?
Authors: Fracalanza Paulo Sérgio , Ferreira Adriana Nunes , Neves Marcos Fava
Published: March 2008

This study aims at examining the resource allocation and welfare implications of the reduction of barriers in the United States market for Frozen Concentrated Orange Juice (FCOJ) imported from Brazil. The present paper is organized as follows: section 2 presents an overview of the main features of the market and current trade regime for orange juice, as well as the possible impacts of liberalization within FTAA and with the European Union; section 3 describes the partial equilibrium model of imperfect substitute goods used to estimate the impact of trade liberalization in the United States, on prices and quantities and on welfare; in section 4 two possible scenarios for liberalization are designed using the large country model. The last section summarizes the main conclusions.
Product reliability and warranty: an overview and future research
Authors: Murthy D.N.P.
Published: March 2008

Reliability and warranty are very important in the context of new products. This paper gives an overview of product reliability and warranty and discusses some issues and challenges for future research.
Coordenação da qualidade: proposta de estrutura e método para cadeias de produção agroalimentares
Authors: Borrás Miguel Angel Aires , Toledo José Carlos de
Published: March 2008

A realidade competitiva vivenciada pelas empresas desestimula que elas ajam de forma isolada, requerendo ações coordenadas com outras empresas da mesma cadeia. Por essa razão, a busca pela coordenação de cadeias de produção visando à melhoria da qualidade do produto e à redução dos custos associados às perdas da produção e aos custos de transação está se tornando uma prática mais comumente adotada por empresas que partilham o objetivo de adicionar valor e competitividade ao produto final da cadeia. Este artigo aborda o problema da coordenação da qualidade em cadeias de produção agroalimentares (CPAs). Com base em conceitos da revisão bibliográfica e de evidências empíricas, são propostos uma Estrutura (ECQ - Estrutura para Coordenação da Qualidade) e um Método (MCQ - Método para Coordenação da Qualidade) para a coordenação da qualidade em CPAs. Em algumas cadeias, a implementação da ECQ/MCQ vem sendo ilustrada bem como usada como alternativa técnica possível e confiável para coordenar e garantir a qualidade do produto final.
Otimização conjunta de gráficos de X-barra - S ou X-barra - R: um procedimento de fácil implementação
Authors: Epprecht Eugenio K. , Leiras Adriana
Published: March 2008

Este trabalho desenvolve um modelo para escolha ótima dos parâmetros de operação de gráficos de X-barra e R (ou de X-barra e S) que minimiza a razão entre o custo de amostragem e a rapidez de detecção de desvios na média ou aumentos na dispersão do processo. Admitem-se três formas alternativas para o problema: minimizar os tempos médios de sinalização sob uma restrição ao custo de amostragem; minimizar esse custo sob uma restrição aos tempos de sinalização; e o problema multiobjetivo de minimizar o custo e os tempos de sinalização. Restrições adicionais são permitidas, para tratar de variantes do problema encontráveis na prática. O procedimento evita a complexidade dos modelos de projeto econômico usuais. São detalhados métodos para determinação dos poucos parâmetros de especificação e entrada exigidos pelo modelo. Um exemplo mostra que o procedimento é de fácil aplicação. Tudo isto aumenta sua aplicabilidade para um grande espectro de situações práticas típicas.