bluuebunny/crossref_metadata_2025 huggingface dataset:
Principles of event segmentation in language: The case of motion events
Authors: Bohnemeyer Jürgen , Enfield N. J. , Essegbey James , Ibarretxe-Antunano Iraide , Kita Sotaro , Lüpke Friederike , Ameka Felix K
Published: December 2007

We examine universals and crosslinguistic variation in constraints on event segmentation. Previous typological studies have focused on segmentation into syntactic (Pawley 1987) or intonational units (Givón 1991). We argue that the correlation between such units and semantic/conceptual event representations is language-specific. As an alternative, we introduce the MACRO-EVENT PROPERTY (MEP): a construction has the MEP if it packages event representations such that temporal operators necessarily have scope over all subevents. A case study on the segmentation of motion events into macro-event expressions in eighteen genetically and typologically diverse languages has produced evidence of two types of design principles that impact motion-event segmentation: language-specific lexicalization patterns and universal constraints on form-to-meaning mapping.
Forty years of language change on Martha's Vineyard
Authors: Pope Jennifer , Meyerhoff Miriam , Ladd D. Robert
Published: December 2007

This short report presents results from a replication of Labov's study of language variation and language change in progress on Martha's Vineyard (MV). The original paper was revolutionary in many respects: it established that the relationship between social and linguistic variables could be systematically studied, and put forward the construct of apparent time as a means of inferring diachronic change in progress based on synchronic patterns. By drawing on Labov's methods for a restudy of MV forty years later, we establish (i) the validity of apparent-time inferencing, and (ii) the robustness of social indexing for the (ay) and (aw) variables on MV. The results strengthen both methodological and theoretical principles that have become central to (socio)linguistics.
Victorian Chimeras, or, What Literature Can Contribute to Genetics Policy Today
Authors: Clayton Jay
Published: December 2007

Through a comparison of H.G. Wells's The Island of Dr. Moreau and Thomas Huxley's writings with recent U.S. policy decisions concerning stem cell research and the creation of chimeras, this article proposes that literary study should play a greater role in genetics policy debates. Cultural representations of genetics carry wide influence, and ethics commissions increasingly invoke literary and historical precedents to buttress their conclusions. Yet literary scholars and others in the humanities have largely been absent from the policy arena. Because of institutional shifts in the policy sphere, humanists have an opportunity to affect public policy more profoundly than at any time since the Victorian era.
Medical Racism and the Rhetoric of Exculpation: How Do Physicians Think about Race?
Authors: Hoberman John M. (John Milton)
Published: December 2007

Over the course of the past two decades, the medical literature has published many peer-reviewed studies pointing to racially differential diagnosis and treatment by American physicians. These publications eventually produced an official report by the Institute of Medicine of the National Academies (Unequal Treatment, 2003) that confirmed the existence of widespread racial health disparities. Yet the detection and prevention of racially motivated misconduct by physicians has never made it onto the agenda of American medicine. The medical publications that do raise questions about differential (and potentially harmful) diagnosis and treatment, while essential to understanding the racial dimension of medicine, focus primarily on relieving medical practitioners of any responsibility for their racially motivated behaviors. Medical authors have developed a rhetoric and a euphemistic vocabulary that aim at preserving the humane reputation of the medical profession. This evasive strategy is reinforced by physicians' ignorance of the history of medical racism in the United States. Improved race relations within American medicine will come about when the medical profession confronts its own legacy of medical racism and requires physicians to learn something about how doctors think about race.
The New Global Health Movement: Rx for the World?
Authors: Lewis Bradley
Published: December 2007

World health is at a critical crossroads. Diseases such as malaria, tuberculosis, and HIV/AIDS ravage many parts of the globe and new diseases such as SARS, West Nile virus, and avian flu threaten to spread quickly and virulently. A new global health movement is rapidly emerging to bring medical solutions to these immense world health problems. Desirable as this goal may be there are multiple negative consequences and side effects associated with this new movement. Using a biocultural approach, this article considers the wider social and cultural complications of the global health movement and questions whether the movement can really offer an untainted Rx for the world's ills.
Immediate Reward Bias in Humans: Fronto-Parietal Networks and a Role for the Catechol-O-Methyltransferase 158Val/ValGenotype
Authors: Boettiger Charlotte A. , Mitchell Jennifer M. , Tavares Venessa C. , Robertson Margaret , Joslyn Geoff , D'Esposito Mark , Fields Howard L.
Published: December 2007

The tendency to choose lesser immediate benefits over greater long-term benefits characterizes alcoholism and other addictive disorders. However, despite its medical and socioeconomic importance, little is known about its neurobiological mechanisms. Brain regions that are activated when deciding between immediate or delayed rewards have been identified (McClure et al., 2004, 2007), as have areas in which responses to reward stimuli predict a paper-and-pencil measure of temporal discounting (Hariri et al., 2006). These studies assume “hot” and “cool” response selection systems, with the hot system proposed to generate impulsive choices in the presence of a proximate reward. However, to date, brain regions in which the magnitude of activity during decision making reliably predicts intertemporal choice behavior have not been identified. Here we address this question in sober alcoholics and non-substance-abusing control subjects and show that immediate reward bias directly scales with the magnitude of functional magnetic resonance imaging bold oxygen level-dependent (BOLD) signal during decision making at sites within the posterior parietal cortex (PPC), dorsal prefrontal cortex (dPFC), and rostral parahippocampal gyrus regions. Conversely, the tendency of an individual to wait for a larger, delayed reward correlates directly with BOLD signal in the lateral orbitofrontal cortex. In addition, genotype at the Val158Met polymorphism of the catechol-O-methyltransferase gene predicts both impulsive choice behavior and activity levels in the dPFC and PPC during decision making. These genotype effects remained significant after controlling for alcohol abuse history. These results shed new light on the neurobiological underpinnings of temporal discounting behavior and identify novel behavioral and neural consequences of genetic variation in dopamine metabolism.
FMRP Phosphorylation Reveals an Immediate-Early Signaling Pathway Triggered by Group I mGluR and Mediated by PP2A
Authors: Narayanan Usha , Nalavadi Vijayalaxmi , Nakamoto Mika , Pallas David C. , Ceman Stephanie , Bassell Gary J. , Warren Stephen T.
Published: December 2007

Fragile X syndrome is a common form of inherited mental retardation and is caused by loss of fragile X mental retardation protein (FMRP), a selective RNA-binding protein that influences the translation of target messages. Here, we identify protein phosphatase 2A (PP2A) as an FMRP phosphatase and report rapid FMRP dephosphorylation after immediate group I metabotropic glutamate receptor (mGluR) stimulation (<1 min) in neurons caused by enhanced PP2A enzymatic activity. In contrast, extended mGluR activation (1–5 min) resulted in mammalian target of rapamycin (mTOR)-mediated PP2A suppression and FMRP rephosphorylation. These activity-dependent changes in FMRP phosphorylation were also observed in dendrites and showed a temporal correlation with the translational profile of select FMRP target transcripts. Collectively, these data reveal an immediate-early signaling pathway linking group I mGluR activity to rapid FMRP phosphorylation dynamics mediated by mTOR and PP2A.
Action and Outcome Encoding in the Primate Caudate Nucleus
Authors: Lau Brian , Glimcher Paul W.
Published: December 2007

The basal ganglia appear to have a central role in reinforcement learning. Previous experiments, focusing on activity preceding movement execution, support the idea that dorsal striatal neurons bias action selection according to the expected values of actions. However, many phasically active striatal neurons respond at a time too late to initiate or select movements. Given the data suggesting a role for the basal ganglia in reinforcement learning, postmovement activity may therefore reflect evaluative processing important for learning the values of actions. To better understand these postmovement neurons, we determined whether individual striatal neurons encode information about saccade direction, whether a reward had been received, or both. We recorded from phasically active neurons in the caudate nucleus while monkeys performed a probabilistically rewarded delayed saccade task. Many neurons exhibited peak responses after saccade execution (77 of 149) that were often tuned for the direction of the preceding saccade (61 of 77). Of those neurons responding during the reward epoch, one subset showed direction tuning for the immediately preceding saccade (43 of 60), whereas another subset responded differentially on rewarded versus unrewarded trials (35 of 60). We found that there was relatively little overlap of these properties in individual neurons. The encoding of action and outcome was performed by largely separate populations of caudate neurons that were active after movement execution. Thus, striatal neurons active primarily after a movement appear to be segregated into two distinct groups that provide complimentary information about the outcomes of actions.
Conditional Knock-Out of β-Cateninin Postnatal-Born Dentate Gyrus Granule Neurons Results in Dendritic Malformation
Authors: Gao Xiang , Arlotta Paola , Macklis Jeffrey D. , Chen Jinhui
Published: December 2007

Neurons are continuously added to the brain throughout life, and these neurons must develop dendritic arbors and functional connections with existing neurons to be integrated into neuronal circuitry. The molecular mechanisms that regulate dendritic development of newborn neurons in the hippocampal dentate gyrus are still unclear. Here, we show that β-catenin is expressed in newborn granule neurons and in neural progenitor cells in the hippocampal dentate gyrus. Specific knock-out of β-cateninin newborn neurons, without affecting β-catenin expression in neural progenitor cells, led to defects in dendritic morphology of these newborn neuronsin vivo. Majority of newborn neurons that cannot extend dendrites survive <1 month after they were born. Our results indicate that β-catenin plays an important role in dendritic development of postnatal-born neuronsin vivo, and is therefore essential for the neurogenesis in the postnatal brain.
Focusing Effect of Acetylcholine on Neuroplasticity in the Human Motor Cortex
Authors: Kuo Min-Fang , Grosch Jan , Fregni Felipe , Paulus Walter , Nitsche Michael A.
Published: December 2007

Cholinergic neuromodulation is pivotal for arousal, attention, and cognitive processes. Loss or dysregulation of cholinergic inputs leads to cognitive impairments like those manifested in Alzheimer's disease. Such dysfunction can be at least partially restored by an increase of acetylcholine (ACh). In animal studies, ACh selectively facilitates long-term excitability changes induced by feed-forward afferent input. Consequently, it has been hypothesized that ACh enhances the signal-to-noise ratio of input processing. However, the neurophysiological foundation for its ability to enhance cognition in humans is not well documented. In this study we explore the effects of rivastigmine, a cholinesterase inhibitor, on global and synapse-specific forms of cortical plasticity induced by transcranial direct current stimulation (tDCS) and paired associative stimulation (PAS) on 10–12 healthy subjects, respectively. Rivastigmine essentially blocked the induction of the global excitability enhancement elicited by anodal tDCS and revealed a tendency to first reduce and then stabilize cathodal tDCS-induced inhibitory aftereffects. However, ACh enhanced the synapse-specific excitability enhancement produced by facilitatory PAS and consolidated the inhibitory PAS-induced excitability diminution. These findings are in line with a cholinergic focusing effect that optimizes the detection of relevant signals during information processing in humans.
Quantitative Analysis of Calcium-Dependent Vesicle Recruitment and Its Functional Role at the Calyx of Held Synapse
Authors: Hosoi Nobutake , Sakaba Takeshi , Neher Erwin
Published: December 2007

Recruitment of release-ready vesicles at synapses is one of the important factors, which determine dynamic properties of signaling between neurons in the brain. It has been shown that the rate of vesicle recruitment is accelerated by strong synaptic activity. An elevated concentration of calcium ions in the presynaptic terminal ([Ca2+]i) has been proposed to be responsible for this effect. However, the precise relationship between [Ca2+]iand recruitment has not been established yet, and the functional consequences of accelerated recruitment during synaptic activity have not been quantified experimentally. To probe the intracellular Ca2+dependence of vesicle recruitment and to examine its functional role during trains of action potential (AP)-like stimuli, we monitored [Ca2+]iand synaptic responses simultaneously with paired recordings at the calyx of Held synapse. We found that a distinct, rapidly releasing vesicle pool is replenished with a rate that increases linearly with [Ca2+]i, without any apparent cooperativity. The slope factor for this increase is ∼1 pool/(μm·s). Blocking Ca2+-dependent recruitment specifically with a calmodulin binding peptide revealed that the steady-state EPSCs during 100 Hz AP-like trains were maintained through this Ca2+-dependent recruitment mechanism. Using a simple model of vesicle dynamics, we estimated that the recruitment rate accelerated 10-fold during the steady-state compared with the rate at resting [Ca2+]i. We could also demonstrate an approximate sixfold increase in release probability (facilitation) during the initial 5–15 AP-like stimuli of such trains in our experimental condition, regardless of EPSC depression.
Parietal Lobe and Episodic Memory: Bilateral Damage Causes Impaired Free Recall of Autobiographical Memory
Authors: Berryhill Marian E. , Phuong Lisa , Picasso Lauren , Cabeza Roberto , Olson Ingrid R.
Published: December 2007

Does the parietal lobe have a critical role in memory? The neuroimaging literature indicates that it has an important role, especially in episodic memory. However, the neuropsychological literature suggests that its role is more limited to attentional, spatial, or imagery aspects of memory. Here, we present data to adjudicate this disagreement. Two patients with bilateral parietal lobe damage received detailed assessments of their autobiographical memories. The results show that although both patients easily recalled various memories, their freely recalled memories were relatively impoverished, lacking in detail. This deficit was ubiquitous, and not limited to spatial or perceptual aspects of memory. The memory deficit disappeared when memory was specifically probed by asking pointed questions. Additional tests show that it is unlikely that their free recall deficit can be explained by general mental imagery problems. In sum, the parietal lobe appears to have a critical role in recollection aspects of episodic memory.
RGS9–2 Negatively Modulates l-3,4-Dihydroxyphenylalanine-Induced Dyskinesia in Experimental Parkinson's Disease
Authors: Gold Stephen J. , Hoang Chau V. , Potts Bryan W. , Porras Gregory , Pioli Elsa , Kim Ki Woo , Nadjar Agnes , Qin Chuan , LaHoste Gerald J. , Li Qin , Bioulac Bernard H. , Waugh Jeffrey L. , Gurevich Eugenia , Neve Rachael L. , Bezard Erwan
Published: December 2007

Chronicl-dopa treatment of Parkinson's disease (PD) often leads to debilitating involuntary movements, termedl-dopa-induced dyskinesia (LID), mediated by dopamine (DA) receptors. RGS9–2 is a GTPase accelerating protein that inhibits DA D2 receptor-activated G proteins. Herein, we assess the functional role of RGS9–2 on LID. In monkeys, Western blot analysis of striatal extracts shows that RGS9–2 levels are not altered by MPTP-induced DA denervation and/or chronicl-dopa administration. In MPTP monkeys with LID, striatal RGS9–2 overexpression – achieved by viral vector injection into the striatum – diminishes the involuntary movement intensity without lessening the anti-parkinsonian effects of the D1/D2 receptor agonistl-dopa. In contrasts, in these animals, striatal RGS9–2 overexpression diminishes both the involuntary movement intensity and the anti-parkinsonian effects of the D2/D3 receptor agonist ropinirole. In unilaterally 6-OHDA-lesioned rats with LID, we show that the time course of viral vector-mediated striatal RGS9–2 overexpression parallels the time course of improvement ofl-dopa-induced involuntary movements. We also find that unilateral 6-OHDA-lesioned RGS9−/−mice are more susceptible tol-dopa-induced involuntary movements than unilateral 6-OHDA-lesioned RGS9+/+mice, albeit the rotational behavior – taken as an index of the anti-parkinsonian response – is similar between the two groups of mice. Together, these findings suggest that RGS9–2 plays a pivotal role in LID pathophysiology. However, the findings also suggest that increasing RGS9–2 expression and/or function in PD patients may only be a suitable therapeutic strategy to control involuntary movements induced by nonselective DA agonist such asl-dopa.
Proprioceptive Sensory Neuropathy in Mice with a Mutation in the Cytoplasmic Dynein Heavy Chain 1 Gene
Authors: Chen Xiang-Jun , Levedakou Eleni N. , Millen Kathleen J. , Wollmann Robert L. , Soliven Betty , Popko Brian
Published: December 2007

Mice heterozygous for the radiation-induced Sprawling (Swl) mutation display an early-onset sensory neuropathy with muscle spindle deficiency. The lack of an H reflex despite normal motor nerve function in the hindlimbs of these mutants strongly suggests defective proprioception. Immunohistochemical analyses reveal that proprioceptive sensory neurons are severely compromised in the lumbar dorsal root ganglia of newbornSwl/+ mice, whereas motor neuron numbers remain unaltered even in aged animals. We have used positional cloning to identify a nine base-pair deletion in the cytoplasmic dynein heavy chain 1 gene (Dync1h1) in this mutant. Furthermore, we demonstrate thatLoa/+ mice, which have previously been shown to carry a missense point mutation inDync1h1that results in late-onset motor neuron loss, also present with a severe, early-onset proprioceptive sensory neuropathy. Interestingly, in contrast to theLoamutation, theSwlmutation does not delay disease progression in a motor neuron disease mouse model overexpressing a human mutant superoxide dismutase (SOD1G93A) transgene. Together, we providein vivoevidence that distinct mutations in cytoplasmic dynein can either result in a pure sensory neuropathy or in a sensory neuropathy with motor neuron involvement.
Mechanosensory Gating of Proprioceptor Input to Modulatory Projection Neurons
Authors: Beenhakker Mark P. , Kirby Matthew S. , Nusbaum Michael P.
Published: December 2007

Sensorimotor gating commonly occurs at sensory neuron synapses onto motor circuit neurons and motor neurons. Here, using the crab stomatogastric nervous system, we show that sensorimotor gating also occurs at the level of the projection neurons that activate motor circuits. We compared the influence of the gastro-pyloric receptor (GPR) muscle stretch-sensitive neuron on two projection neurons, modulatory commissural neuron 1 (MCN1) and commissural projection neuron 2 (CPN2), with and without a preceding activation of the mechanosensory ventral cardiac neurons (VCNs). MCN1 and CPN2 project from the paired commissural ganglia (CoGs) to the stomatogastric ganglion (STG), where they activate the gastric mill (chewing) motor circuit. When stimulated separately, the GPR and VCN neurons each elicit the gastric mill rhythm by coactivating MCN1 and CPN2. When GPR is instead stimulated during the VCN-gastric mill rhythm, it slows this rhythm. This effect results from a second GPR synapse onto MCN1 that presynaptically inhibits its STG terminals. Here, we show that, during the VCN-triggered rhythm, the GPR excitation of MCN1 and CPN2 in the CoGs is gated out, leaving only its influence in the STG. This gating effect appears to occur within the CoG and does not result from a ceiling effect on projection neuron firing frequency. Additionally, this gating action enables GPR to either activate rhythmic motor activity or act as a phasic sensorimotor feedback system. These results also indicate that the site of sensorimotor gating can occur at the level of the projection neurons that activate a motor circuit.
NMDA Receptor Activation Potentiates Inhibitory Transmission through GABA Receptor-Associated Protein-Dependent Exocytosis of GABAAReceptors
Authors: Marsden Kurt C. , Beattie Jennifer B. , Friedenthal Jenna , Carroll Reed C.
Published: December 2007

The trafficking of postsynaptic AMPA receptors (AMPARs) is a powerful mechanism for regulating the strength of excitatory synapses. It has become clear that the surface levels of inhibitory GABAAreceptors (GABAARs) are also subject to regulation and that GABAAR trafficking may contribute to inhibitory plasticity, although the underlying mechanisms are not fully understood. Here, we report that NMDA receptor activation, which has been shown to drive excitatory long-term depression through AMPAR endocytosis, simultaneously increases expression of GABAARs at the dendritic surface of hippocampal neurons. This NMDA stimulus increases miniature IPSC amplitudes and requires the activity of Ca2+calmodulin-dependent kinase II and the trafficking proteinsN-ethylmaleimide-sensitive factor, GABA receptor-associated protein (GABARAP), and glutamate receptor interacting protein (GRIP). These data demonstrate for the first time that endogenous GABARAP and GRIP contribute to the regulated trafficking of GABAARs. In addition, they reveal that the bidirectional trafficking of AMPA and GABAAreceptors can be driven by a single glutamatergic stimulus, providing a potent postsynaptic mechanism for modulating neuronal excitability.
Olig1 and Sox10 Interact Synergistically to DriveMyelin Basic ProteinTranscription in Oligodendrocytes
Authors: Li Huiliang , Lu Yan , Smith Hazel K. , Richardson William D.
Published: December 2007

The oligodendrocyte lineage genes (Olig1/2), encoding basic helix-loop-helix transcription factors, were first identified in screens for master regulators of oligodendrocyte development. OLIG1 is important for differentiation of oligodendrocyte precursors into myelin-forming oligodendrocytes during development and is thought to play a crucial role in remyelination during multiple sclerosis. However, it is still unclear how OLIG1 interacts with its transcriptional cofactors and DNA targets. OLIG1 was reportedly restricted to mammals, but we demonstrate here that zebrafish and other teleosts also possess an OLIG1 homolog. In zebrafish, as in mammals, Olig1 is expressed in the oligodendrocyte lineage. Olig1 associates physically with another myelin-associated transcription factor, Sox10, and the Olig1/Sox10 complex activatesmbp(myelin basic protein) transcription via conserved DNA sequence motifs in thembppromoter region. In contrast, Olig2 does not bind to Sox10 in zebrafish, although both OLIG1 and OLIG2 bind SOX10 in mouse.
Dimensions of Impulsivity Are Associated with Poor Spatial Working Memory Performance in Monkeys
Authors: James Alex S. , Groman Stephanie M. , Seu Emanuele , Jorgensen Matthew , Fairbanks Lynn A. , Jentsch J. David
Published: December 2007

Impulsive behavior and novelty seeking are dimensions of temperament that are behavioral determinants of risk for attention deficit/hyperactivity disorder and its neurocognitive endophenotypes, and variation in the dopamine D4receptor gene (DRD4) explains at least a portion of the variance in the traits. To further characterize the dimensional phenotype associated with impulsiveness, adolescent male monkeys were evaluated using ecologically valid tests of impulsive approach and aggression in response to social or nonsocial stimuli; subsequently, a delayed response task was implemented to assess spatial working memory performance. Subjects were selected into this study based on their response to the social challenge task or by DRD4 genotype, resulting in three groups: low-impulsivity/common DRD4 allele, high-impulsivity/common DRD4 allele, or rare DRD4 allele. All animals acquired the delayed response task and could perform at near ceiling levels when a ∼0 s delay version was imposed, but as delays were lengthened, high-impulsive animals, regardless of DRD4 genotype, made fewer correct responses than did low-impulsive subjects; an inverse relationship existed for working memory and impulsivity. Notably, impulsive behavior evoked by social and nonsocial stimuli explained overlapping and independent portions of the variance in working memory performance. CSF levels of monoamine metabolites did not significantly differentiate the high- and low-impulsive animals, although monkeys carrying the DRD4 rare allele tended to exhibit higher monoamine turnover. These data indicate that dimensions of impulsivity may impact on working memory performance in qualitatively similar ways but through different mechanisms.
Mosaic Removal of Hedgehog Signaling in the Adult SVZ Reveals That the Residual Wild-Type Stem Cells Have a Limited Capacity for Self-Renewal
Authors: Balordi Francesca , Fishell Gord
Published: December 2007

TheSmoothenedgene is necessary for cells to transduce hedgehog signaling. Although we and others have previously shown that embryonic removal ofSmoothenedin the neural tube results in a loss of stem cells from the postnatal subventricular zone, it was unclear whether this reflected a requirement for hedgehog signaling in the establishment or maintenance of the adult niche. Here, we have examined the consequences of conditional removal ofSmoothenedgene function within the subventricular zone of the adult neural stem cell niche. We observe that both proliferation and neurogenesis are compromised when hedgehog signaling is removed from subventricular zone stem cells. Moreover, even after a 10 month survival period, the stem cell niche fails to recover. It has been reported that the adult subventricular zone quickly rebounds from an antimitotic insult by increasing proliferation and replenishing the niche. During this recovery, it has been reported that hedgehog signaling appears to be upregulated. When mice in which hedgehog signaling in the subventricular zone has been strongly attenuated are given a similar antimitotic treatment, recovery is limited to the reduced level of proliferation and neurogenesis observed before the mitotic insult. Furthermore, the limited recovery that is observed appears to be largely restricted to the minority of neural stem cells that escape the conditional inactivation ofSmoothenedgene function. These results demonstrate that ongoing hedgehog signaling is required to maintain adult neural stem cells and that their ability to self-renew is limited.
Human Neuroma Contains Increased Levels of Semaphorin 3A, Which Surrounds Nerve Fibers and Reduces Neurite ExtensionIn Vitro
Authors: Tannemaat Martijn R. , Korecka Joanna , Ehlert Erich M. E. , Mason Matthew R. J. , van Duinen Sjoerd G. , Boer Gerard J. , Malessy Martijn J. A. , Verhaagen Joost
Published: December 2007

Neuroma formation after peripheral nerve injury is detrimental to functional recovery and is therefore a significant clinical problem. The molecular basis for this phenomenon is not fully understood. Here, we show that the expression of the chemorepulsive protein semaphorin 3A (sema3A), but not semaphorin 3F, is increased in human neuroma tissue that has formed in severe obstetric brachial plexus lesions. Sema3A is produced by fibroblasts in the epineurial space and appears to be secreted into the extracellular matrix. It surrounds fascicles, minifascicles, or single axons, suggesting a role in fasciculation and inhibition of neurite outgrowth. Lentiviral vector-mediated knock-down of Neuropilin 1, the receptor for sema3A, leads to increased neurite outgrowth of F11 cells cultured on neuroma tissue, but not of F11 cells cultured on normal nerve tissue. These findings demonstrate the putative inhibitory role of sema3A in human neuroma tissue. Our observations are the first demonstration of the expression of sema3A in human neural scar tissue and support a role for this protein in the inhibition of axonal regeneration in injured human peripheral nerves. These findings contribute to the understanding of the outgrowth inhibitory properties of neuroma tissue.
A Critical Function for β-Amyloid Precursor Protein in Neuronal Migration Revealed byIn UteroRNA Interference
Authors: Young-Pearse Tracy L. , Bai Jilin , Chang Rui , Zheng Jessica B. , LoTurco Joseph J. , Selkoe Dennis J.
Published: December 2007

Physiological processing of the β-amyloid precursor protein (APP) generates amyloid β-protein, which can assemble into oligomers that mediate synaptic failure in Alzheimer's disease. Two decades of research have led to human trials of compounds that chronically target this processing, and yet the normal function of APPin vivoremains unclear. We used the method ofin uteroelectroporation of shRNA constructs into the developing cortex to acutely knock down APP in rodents. This approach revealed that neuronal precursor cells in embryonic cortex require APP to migrate correctly into the nascent cortical plate. cDNAs encoding human APP or its homologues, amyloid precursor-like protein 1 (APLP1) or APLP2, fully rescued the shRNA-mediated migration defect. Analysis of an array of mutations and deletions in APP revealed that both the extracellular and cytoplasmic domains of APP are required for efficient rescue. Whereas knock-down of APP inhibited cortical plate entry, overexpression of APP caused accelerated migration of cells past the cortical plate boundary, confirming that normal APP levels are required for correct neuronal migration. In addition, we found that Disabled-1 (Dab1), an adaptor protein with a well established role in cortical cell migration, acts downstream of APP for this function in cortical plate entry. We conclude that full-length APP functions as an important factor for proper migration of neuronal precursors into the cortical plate during the development of the mammalian brain.
Liver X Receptor Activation Enhances Cholesterol Loss from the Brain, Decreases Neuroinflammation, and Increases Survival of the NPC1 Mouse
Authors: Repa Joyce J. , Li Hao , Frank-Cannon Tamy C. , Valasek Mark A. , Turley Stephen D. , Tansey Malú G. , Dietschy John M.
Published: December 2007

Although cholesterol is a major component of the CNS, there is little information on how or whether a change in sterol flux across the blood–brain barrier might alter neurodegeneration. In Niemann-Pick type C (NPC) disease, a mutation in NPC1 protein causes unesterified cholesterol to accumulate in the lysosomal compartment of every cell, including neurons and glia. Using the murine model of this disease, we used genetic and pharmacologic approaches in an attempt to alter cholesterol homeostasis across the CNS. Genetic deletion of the sterol transporters ATP-binding cassette transporter A1 (ABCA1) and low-density lipoprotein receptor in the NPC1 mouse did not affect sterol balance or longevity. However, deletion of the nuclear receptor, liver X receptor β (LXRβ), had an adverse effect on progression of the disease. We therefore tested the effects of increasing LXR activity by oral administration of a synthetic ligand for this transcription factor. Treatment with this LXR agonist increased cholesterol excretion out of brain from 17 to 49 μg per day, slowed neurodegeneration, and prolonged life. This agonist did not alter synthesis of cholesterol or expression of genes associated with the formation of 24(S)-hydroxycholesterol or neurosteroids such as CYP46A1, 3αHSD, and CYP11A1. However, levels of the sterol transporters ABCA1 and ATP-binding cassette transporter G1 were increased. Concomitantly, markers of neuroinflammation, CD14, MAC1, CD11c, and inducible nitric oxide synthase, were reduced, and microglia reverted from their amoeboid, active form to a ramified, resting configuration. Thus, LXR activation resulted in increased cholesterol excretion from the brain, decreased neuroinflammation, and deactivation of microglia to slow neurodegeneration and extend the lifespan of the NPC1 mouse.
Identification of Strain-Specific Genes in Using a Modified HiCEP Method
Authors: Mitani Yasuo , Watanabe Tsuneaki , Kondo Kazuhiro , Tamura Tomohiro
Published: December 2007

The genus Rhodococcus exhibits a broad catabolic diversity that is often related to unusual genome diversity. A
modified HiCEP method was applied for the identification of strain-specific genes by comparing two different strains.
Rhodococcus erythropolis JCM3201 and NI86/21 were compared and 11 genes were identified as NI86/21-specific genes.
Evaluation of Practical Process Aspects for Lipozyme TL IM Catalyzed Bulk Fat Modification in a Batch Reactor
Authors: Zhang Hong
Published: December 2007

A few issues to apply Lipozyme TL IM-catalyzed interesterification for bulk fat modification were investigated
in a batch reactor system with concerning practical process development. The hydrolyzed products, i.e. free fatty acids
and diglycerides, generated from the Lipozyme TL IM-catalyzed interesterification process due to water participation, can
be minimized by enzyme pre-treatment. For the interesterified products, free fatty acids formed by hydrolysis had softening
effect on solid fat content and diglycerides retarded crystal transformation during storage. Reaction time was more
critical for the reduction of acyl migration than the control of water content in the system. The temperature effect on the
rate of interesterification in terms of Q10 value was determined as 1.3, meaning that the increase of reaction rate was limited
by the increase of temperature. Therefore, for practical implementations, a temperature of 60-70 °C which the feed
stock can be totally melted for the reaction should be used in consideration of enzyme stability. The quality of feedstock
was confirmed to be critical to maintain the enzyme activity and the refined, bleached, and deodorized oil should be used
as the feedstock.
A System for the Synchronized Recording of Sonomyography, Electromyography and Joint Angle
Authors: Huang Q.H , Zheng Y.P , Chena X , He J.F , Shi J
Published: December 2007

Ultrasound and electromyography (EMG) are two of the most commonly used diagnostic tools for the assessment of muscles. Recently, many studies reported the simultaneous collection of EMG signals and ultrasound images, which were normally amplified and digitized by different devices. However, there is lack of a systematic method to synchronize them and no study has reported the effects of ultrasound gel to the EMG signal collection during the simultaneous data collection. In this paper, we introduced a new method to synchronize ultrasound B-scan images, EMG signals, joint angles and other related signals (e.g. force and velocity signals) in real-time. The B-mode ultrasound images were simultaneously captured by the PC together with the surface EMG (SEMG) and the joint angle signal. The deformations of the forearm muscles induced by wrist motions were extracted from a sequence of ultrasound images, named as Sonomyography (SMG). Preliminary experiments demonstrated that the proposed method could reliably collect the synchronized ultrasound images, SEMG signals and joint angle signals in real-time. In addition, the effect of ultrasound gel on the SEMG signals when the EMG electrodes were close to the ultrasound probe was studied. It was found that the SEMG signals were not significantly affected by the amount of the ultrasound gel. The system is being used for the study of contractions of various muscles as well as the muscle fatigue.
The use of differential pulse anodic stripping voltammetry and diffusive gradient in thin films for heavy metals speciation in soil solution
Authors: Dytrtová Jana , Šestáková Ivana , Jakl Michal , Száková Jiřina , Miholová Daniela , Tlustoš Pavel
Published: December 2007

In the soil solutions obtained in situ with suction cups from soils (Cambisol and Fluvisol) of pot experiment with Salix smithiana Smith, Lolium perenne L. and Thlaspi caerulescens J. & C. Presl heavy metals species (Cd, Pb and Cu) were assayed by differential pulse anodic stripping voltammetry and diffusive gradient in thin films. Prediction of accumulation performed best at free metal ion concentrations in unchanged pH (in 10−3 mol L−1 NaClO4 base electrolyte). The speciation provided by differential pulse anodic stripping voltammetry according to pH can provide a detailed description of the soil solution matrix. The concentration of free metals in unchanged pH represents a small part of the total content and varied from 0.04 to 0.75% with two exceptions found for accumulating plants (the content of Cd2+ in the soil solution from T. caerulescens was about 6% and the content of Cu2+ in the soil solution from S. smithiana was about 30%). The available concentration as determined by diffusive gradient in thin films was not in correlation with the heavy metals concentration in plant biomass.
RETRACTED ARTICLE: Kinetic and anion degradation products study on photocatalytic degradation of reactive orange 5 solution with phosphotungstic acid
Authors: Zhong Junbo , Zhao Hong , Ma Di , Lian An , Li Minjiao , Xie Bin , Li Jianzhang
Published: December 2007

Increasing environmental pollution caused by toxic dyes is a matter of great concern due to their hazardous nature. So it is crucial to develop processes which can destroy these dyes effectively. It has been generally agreed that reactive orange 5 (KGN) can be effectively degraded in aerated phosphotungstic acid (HPA) in a homogeneous reaction system using near-UV irradiation. In this paper, photocatalytic degradation of reactive orange 5 solutions with phosphotungstic acid was investigated, especially more attention was paid to the kinetic model and the anion degradation products. The results revealed that the photocatalytic degradation reaction of KGN with HPA in a homogenous solution can be described by Langmuir-Hinshelwood equation and Langmuir-Hinshewood kinetic model described it well. The reaction manifested the first order with lower concentration(⩽30 mg L−1) with the limiting rate constant and the adsorption constant in this case being 0.8098 mg L−1 min−1 and 4.359 10−2 L mg−1, respectively. The degradation mechanism of KGN with HPA is different from that with TiO2, the anion products of the two reaction systems are the same. The difference in degradation mechanism of KGN with HPA from that with TiO2 is caused by the nature of the photocatalyst.
Synthesis and superconducting properties of Nd0.33Eu0.08Gd0.58Ba2Cu3Oz materials
Authors: Stoyanova-Ivanova Angelina , Terzieva Stanimira , Shivachev Boris , Mikli Valdek , Vladimirova Latinaka
Published: December 2007

We have studied the effect of the ratio of different rare-earth element on the superconducting properties and phase formation of (Nd0.33Eu0.08Gd0.58)Ba2Cu3Oz ceramic. Bulk NEG samples were prepared using the solid-state reaction process. The superconducting transition for Nd0.33Eu0.08Gd0.58Ba2Cu3Oz is T
c ≈90 K and the value of the critical current density (J
c) is 13.9 A/cm2 at 77 K under zero magnetic fields. This value is twice as high when compared with the (J
c) value of YBCO systems (J
c = 7.31 A/cm2). The obtained bulk sample was used for the production of superconducting Ag-sheathed tapes by OPIT method including hot rolling. The critical current density of the obtained tape (337 A/cm2) is one order higher than the one of the bulk sample.
Quantum phases for a generalized harmonic oscillator
Authors: Bracken Paul
Published: December 2007

An effective Hamiltonian for the generalized harmonic oscillator is determined by using squeezed state wavefunctions. The equations of motion over an extended phase space are determined and then solved perturbatively for a specific choice of the oscillator parameters. These results are used to calculate the dynamic and geometric phases for the generalized oscillator with this choice of parameters.
Efficacy of alternate day dosing of atorvastatin
Authors: Aghasadeghi Kamran , Zare Didar
Published: December 2007

Atorvastatin is a synthetic inhibitor of 3-hydroxy 3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. It has a longer half life and longer duration of action than that of all other available HMG-CoA inhibitors. We evaluated the efficacy of alternate-day dosing of atorvastatin in comparison with the standard one-daily dose on total cholesterol, low and High-density lipoprotein (LDL and HDL) and triglycerides. This study is a randomized, blinded, and controlled clinical trial. Sixty-six patients with LDL cholesterol of more than 100 mg/dl were enrolled. Baseline fasting lipid profile (total cholesterol, LDL, HDL and triglyceride), liver function tests and creatine kinase were drawn. Patients were randomized to three atorvastatin dose groups. Group I received 10 mg of atorvastatin every day, group II received 20 mg of atorvastatin every day, and group III received 20 mg every other day. After 6 weeks of treatment with atorvastatin, fasting lipid profiles, liver function tests and creatine kinase concentrations were re-taken. Compliance to treatment was assessed at each visit. Of the sixty-six patients enrolled, sixty completed the study. All three regimens significantly reduced total cholesterol and LDL compared to baseline. No statistically significant difference existed between the three groups in regards to total or a percentage decrease in total cholesterol and LDL cholesterol at 6 weeks compared to baseline. All regimens were well tolerated and none of the patients showed significant elevation of liver enzyme or creatine kinase during the course of the study. In conclusions the alternate-day dosing of atorvastatin is an efficacious and safe alternate to daily dosing and yet inexpensive.
Can CYP1A1 siRNA be an effective treatment for lung cancer?
Authors: Mohammed Kulthum , Shervington Amal
Published: December 2007

Abstract: Previously, we identified a novel correlation between the upregulated expression of telomerase (hTERT) and cytochrome P450 1A1 (CYP1A1) in A549 human lung cancer cell line. The expression correlation was confirmed by silencing CYP1A1 expression using siRNA technology and observing a silencing of hTERT transcription. Furthermore, silencing CYP1A1 and subsequently downregulating hTERT resulted in the reduction of cancer cell viability by more than 40%, which appeared as early as 24 hours after the treatment. The concomitant downregulation of CYP1A1 and hTERT resulted in rapid cell death. This finding can be further exploited to develop new molecular targets for the treatment of lung cancer.
The cytoplasmic domain of chondrolectin interacts with the β-subunit of rab geranylgeranyl transferase
Authors: Claessens An , Weyn Christine , Merregaert Joseph
Published: December 2007

Mouse chondrolectin (chodl) was isolated out of the tail tip of four-day old 129/SvJ mice as a by-product of a PCR-based subtractive cDNA library screening. The gene is predominantly expressed in adult skeletal muscle, heart, testes and lungs and in embryonic stadia. Chodl is the mouse homologue of human chondrolectin (CHODL), a gene that encodes for a type Ia transmembrane protein and that is expressed in human testis, prostate, heart and skeletal muscle tissue. CHODL-splice variants (CHODL f, CHODL fΔE, CHODL ΔE) are detected in human leukocytes. The proteins of the chondrolectin family belong to the family of C-type lectins. As the members of this protein family are important for a wide array of biological processes, the function of chodl was investigated by searching for its protein interaction partners. The β-subunit of Rab geranylgeranyl transferase (Rabggtb) was isolated 8 times after a complete Sos recruitment system (SRS) screen with the cytoplasmic domain of chodl. The interaction was confirmed with in vitro transcription/translation and co-immunoprecipitation (co-IP) experiments.
Ordering of diagnostic information in encoded medical images. Accuracy progression
Authors: Przelaskowski A. , Jóźwiak R. , Krzyżewski T. , Wróblewska A.
Published: December 2007

A concept of diagnostic accuracy progression for embedded coding of medical images was presented. Implementation of JPEG2000 encoder with a modified PCRD optimization algorithm was realized and initially verified as a tool for accurate medical image streaming. Mean square error as a distortion measure was replaced by other numerical measures to revise quality progression according to diagnostic importance of successively encoded image information. A faster increment of image diagnostic importance during reconstruction of initial packets of code stream was reached. Modified Jasper code was initially tested on a set of mammograms containing clusters of microcalcifications and malignant masses, and other radiograms. Teleradiologic applications were considered as the first area of interests.
Digital holographic cameras and data processing for remote monitoring and measurements of mechanical parts
Authors: Michałkiewicz A. , Kujawińska M. , Stasiewicz K.
Published: December 2007

Fast growing technology and requirements for testing of different types of materials and devices require new methods and systems for investigation of their parameters. Among the quantities of high interest are shape, deformation, roughness, local materials constants, displacement, and strain fields of elements under load. In the paper, we present novel solutions for digital holographic cameras, which allow for remote monitoring and measurement of the above mentioned quantities at small mechanical objects or at restricted areas of interest at big structures. The systems have compact design, “black box” measurement approach, and allows for fast and accurate measurements performed directly at the element and often in outdoor environment. The principles of digital and optoelectronic reconstruction and phase manipulation are described together with the exemplary measurement results obtained by means of the cameras presented.