bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparison of retrospectively self-gated magnetic resonance imaging and high-frequency echocardiography for characterization of left ventricular function in mice
Authors: Amundsen Brage Høyem , Ericsson Madelene , Seland John Georg , Pavlin Tina , Ellingsen Øyvind , Brekken Christian
Published: November 2010

Non-invasive imaging methods like echocardiography and magnetic resonance imaging (MRI) are very valuable in longitudinal follow-up studies of cardiac function in small animals. To be able to compare results from studies using different methods, and explain possible differences, it is important to know the agreement between these methods. As both self-gated high-field MRI and high-frequency echocardiography (hf-echo) M-mode are potential methods for evaluation of left ventricular (LV) function in healthy mice, our aim was to assess the agreement between these two methods. Fifteen healthy female C57BL/6J mice underwent both self-gated MRI and hf-echo during the same session of light isoflurane anaesthesia. LV dimensions were estimated offline, and agreement between the methods and reproducibility for the two methods assessed using Bland–Altman methods. In summary, hf-echo M-mode had better inter-observer repeatability than self-gated MRI for all measured parameters. Compared with hf-echo, systolic posterior wall thicknesses were significantly higher when measured by MRI, while diastolic anterior wall thicknesses were found to be significantly smaller. MRI measurements of diastolic LV diameter were also higher using MRI, resulting in larger fractional shortening values compared with the values obtained by hf-echo. In conclusion, hf-echo M-mode is easy to apply, has high temporal and spatial resolution, and good reproducibility. Self-gated MRI might be advantageous in cases of abnormal LV geometry and heterogeneous regional myocardial function, especially with improvements in spatial resolution. The moderate agreement between the methods must be taken into account when comparing studies using the two modalities.
Development of FRP Bridges in the UK — An Overview
Authors: Canning Lee , Luke Sam
Published: November 2010

The emphasis in bridge design and construction technology in the UK has shifted in recent decades towards improved durability and quick construction, with whole life cost and low maintenance gradually becoming as important as initial capital cost. In conjunction with this, reduced disruption to the travelling public has become more important due to general increased travel and congestion on roads and railways. The combination of these two factors was a primary driver in the development of fibre-reinforced polymer (FRP) composite bridge technology, which can provide improved durability and also reduced time of in-situ construction due to large, lightweight components being manufactured off-site (modular construction) and installed simply and quickly. The growth in the application of FRP bridges in the UK is described and highlighted with a number of representative case studies, generally showing the benefits of this technology in reducing whole life cost and disruption to the public. The future work required to further enable the development of FRP bridge technology is described, with the aim of FRP bridges becoming a mainstream competitor to other bridge materials and technologies.
Pedestrian Bridge Vibration Serviceability: A Case Study in Testing and Simulation
Authors: Fanning Paul J. , Healy Paul , Pavic Aleksandar
Published: November 2010

Pedestrian bridges are increasingly becoming landmark structures designed to promote a modern vibrant image of their surrounding landscape. Designs are becoming more daring; spans are increasing and becoming more slender and the use of lightweight materials is more prevalent. The net result is that it is often the serviceability limit state, rather than the ultimate limit state, that controls the bridge design. Sean O'Casey Bridge, Dublin, is the most recently constructed pedestrian bridge over the River Liffey. This articulated steel bridge, designed by O'Connor Sutton Cronin Consulting Engineers following an international design competition, is located in Dublin's docklands and spans approximately 88m across the river. This paper describes the pedestrian crossing tests, experimental modal analyses, and associated numerical modelling undertaken to assess vibration serviceability. The results of these analyses and their implications for the serviceability limit state assessment of pedestrian bridges are discussed in this paper.
An intergenerational and semiotic exploration of hair combs as material culture
Authors: Stokrocki Mary
Published: October 2010

This study explores the value of hair combs as material culture, and their various traditions through the eyes of five intergenerational females (two women and three girls) who visited a retired couple to view examples of their hair comb collection and learn about its worth. A pre-questionnaire revealed the younger females' fascination with shiny details as worthy of attention and the practical considerations of the older women. The elicitation of participants' evolving questions led to the explanation of the importance of the combs by the collectors, an elderly couple. Based on Bolin's material culture categories, a semiotic analysis revealed that they learned about different comb forms, function, decoration, colouring, material, technique, trade practices (illegal poaching), style, date (acquisition), symbolism, condition, authenticity (determining fakes), attribution (cataloguing) and provenance (ownership). They were surprised that men made and wore combs (gender stereotype). Education on caring for these precious things goes beyond the museum walls and schools and should foster such intergenerational questioning and valuing even in classrooms.
A new look at metaphorical creativity in cognitive linguistics
Authors: Kövecses Zoltán
Published: November 2010

Where do we recruit novel and unconventional conceptual materials from when we speak, think and act metaphorically, and why? This question has been partially answered in the cognitive linguistic literature but, in my view, a crucial aspect of it has been left out of consideration or not dealt with in the depth it deserves: it is the effect of various kinds of context on metaphorical conceptualization. Of these, I examine the following: (1) the immediate physical setting, (2) what we know about the major entities participating in the discourse, (3) the immediate cultural context, (4) the immediate social setting, and (5) the immediate linguistic context itself. I suggest that we recruit conceptual materials for metaphorical purposes not only from bodily experience but also from all of these various contexts. Since the contexts can be highly variable, the metaphors used will often be variable, novel, and unconventional. The phenomenon can be observed in both everyday forms of language and literary texts.
Does prosodic constituency signal relative predictability? A Smooth Signal Redundancy hypothesis
Authors: Turk Alice
Published: November 2010

This paper explores issues relating to signaling word boundaries from the perspective of Aylett's Smooth Signal Redundancy proposal (Aylett, Stochastic suprasegmentals: Relationships between redundancy, prosodic structure and care of articulation in spontaneous speech, University of Edinburgh, 2000, Aylett and Turk, Language and Speech 47: 31–56, 2004) that language has evolved to spread redundancy, i.e. recognition likelihood, evenly throughout utterances. In Aylett's proposal, information that enables listeners to identify sequences of elements in an utterance (signal redundancy) comes from two sources: a) language redundancy, recognition likelihood based on lexical, syntactic, semantic, pragmatic and other factors, and b) acoustic redundancy, recognition likelihood based on acoustic salience. Smooth signal redundancy is achieved by a complementary relationship between language redundancy and acoustic redundancy that is implemented via prosodic structure.

While Aylett and Turk (Language and Speech 47: 31–56, 2004) present the case for prosodic prominence as a lever for modulating the acoustic salience of syllables, the current paper proposes that prosodic constituency also fulfils this function for words. The current paper proposes that the signal redundancy, or recognition likelihood, of words can be manipulated by signaling their boundaries, and that the occurrence and strength of these boundary markers correlates inversely with language redundancy. Prosodic constituency implements the complementary relationship between language redundancy and word boundary salience.

Smooth Signal Redundancy provides an integrated explanation for a set of properties relating to prosodic constituent structure.
Talking about quantities in space: Vague quantifiers, context and similarity
Authors: Coventry Kenny R. , Cangelosi Angelo , Newstead Stephen E. , Bugmann Davi
Published: November 2010

In this paper we examine how vague quantifiers, such asfew, several, lots of, map onto non-linguistic number systems. In particular our focus is to examine how judgements about vague quantifiers are affected by the presence of objects in visual scenes other than those being referred to. An experiment is presented that manipulated the number of objects in a visual scene (men playing golf; the ‘focus’ objects) together with the number of other objects in those scenes and their similarity—in terms of form (women or crocodiles) and function (playing golf, not playing golf)—to the focus objects. We show that the number of other objects in a scene impacts upon quantifiers judgements even when those objects are in a different category to the focus objects. We discuss the results in terms of the mapping between the large approximate number (estimation) system and language.
Compound stress assignment by analogy: the constituent family bias
Authors: Plag Ingo
Published: November 2010

This paper tests the hypothesis that stress assignment to English compounds works on the basis of analogy. In particular, the role of the constituent family, i.e. the set of compounds that share the same right or left constituent with a given compound, is investigated. On the basis of large amounts of data from three different corpora it is shown that the tendency towards a certain kind of stress pattern within the constituent families of a given compound is a strong predictor for stress assignment. This challenges rule-based approaches to compound stress assignment and lends independent evidence to exemplar-based approaches to language structure.
DrosophilaGlial Glutamate Transporter Eaat1 Is Regulated by Fringe-Mediated Notch Signaling and Is Essential for Larval Locomotion
Authors: Stacey Stephanie M. , Muraro Nara I. , Peco Emilie , Labbé Alain , Thomas Graham B. , Baines Richard A. , van Meyel Donald J.
Published: October 2010

In the mammalian CNS, glial cells expressing excitatory amino acid transporters (EAATs) tightly regulate extracellular glutamate levels to control neurotransmission and protect neurons from excitotoxic damage. Dysregulated EAAT expression is associated with several CNS pathologies in humans, yet mechanisms of EAAT regulation and the importance of glutamate transport for CNS development and functionin vivoremain incompletely understood.Drosophilais an advanced genetic model with only a single high-affinity glutamate transporter termed Eaat1. We found that Eaat1 expression in CNS glia is regulated by the glycosyltransferase Fringe, which promotes neuron-to-glia signaling through the Delta-Notch ligand–receptor pair during embryogenesis. We madeEaat1loss-of-function mutations and found that homozygous larvae could not perform the rhythmic peristaltic contractions required for crawling. We found no evidence for excitotoxic cell death or overt defects in the development of neurons and glia, and the crawling defect could be induced by postembryonic inactivation ofEaat1. Eaat1 fully rescued locomotor activity when expressed in only a limited subpopulation of glial cells situated near potential glutamatergic synapses within the CNS neuropil.Eaat1mutants had deficits in the frequency, amplitude, and kinetics of synaptic currents in motor neurons whose rhythmic patterns of activity may be regulated by glutamatergic neurotransmission among premotor interneurons; similar results were seen with pharmacological manipulations of glutamate transport. Our findings indicate that Eaat1 expression is promoted by Fringe-mediated neuron–glial communication during development and suggest that Eaat1 plays an essential role in regulating CNS neural circuits that control locomotion inDrosophila.
Vibrotactile Masking Experiments Reveal Accelerated Somatosensory Processing in Congenitally Blind Braille Readers
Authors: Bhattacharjee Arindam , Ye Amanda J. , Lisak Joy A. , Vargas Maria G. , Goldreich Daniel
Published: October 2010

Braille reading is a demanding task that requires the identification of rapidly varying tactile patterns. During proficient reading, neighboring characters impact the fingertip at ∼100 ms intervals, and adjacent raised dots within a character at 50 ms intervals. Because the brain requires time to interpret afferent sensorineural activity, among other reasons, tactile stimuli separated by such short temporal intervals pose a challenge to perception. How, then, do proficient Braille readers successfully interpret inputs arising from their fingertips at such rapid rates? We hypothesized that somatosensory perceptual consolidation occurs more rapidly in proficient Braille readers. If so, Braille readers should outperform sighted participants on masking tasks, which demand rapid perceptual processing, but would not necessarily outperform the sighted on tests of simple vibrotactile sensitivity. To investigate, we conducted two-interval forced-choice vibrotactile detection, amplitude discrimination, and masking tasks on the index fingertips of 89 sighted and 57 profoundly blind humans. Sighted and blind participants had similar unmasked detection (25 ms target tap) and amplitude discrimination (compared with 100 μm reference tap) thresholds, but congenitally blind Braille readers, the fastest readers among the blind participants, exhibited significantly less masking than the sighted (masker, 50 Hz, 50 μm; target–masker delays, ±50 and ±100 ms). Indeed, Braille reading speed correlated significantly and specifically with masking task performance, and in particular with the backward masking decay time constant. We conclude that vibrotactile sensitivity is unchanged but that perceptual processing is accelerated in congenitally blind Braille readers.
A Behavioral and Neural Evaluation of Prospective Decision-Making under Risk
Authors: Symmonds Mkael , Bossaerts Peter , Dolan Raymond J.
Published: October 2010

Making the best choice when faced with a chain of decisions requires a person to judge both anticipated outcomes and future actions. Although economic decision-making models account for both risk and reward in single-choice contexts, there is a dearth of similar knowledge about sequential choice. Classical utility-based models assume that decision-makers select and follow an optimal predetermined strategy, regardless of the particular order in which options are presented. An alternative model involves continuously reevaluating decision utilities, without prescribing a specific future set of choices. Here, using behavioral and functional magnetic resonance imaging (fMRI) data, we studied human subjects in a sequential choice task and use these data to compare alternative decision models of valuation and strategy selection. We provide evidence that subjects adopt a model of reevaluating decision utilities, in which available strategies are continuously updated and combined in assessing action values. We validate this model by using simultaneously acquired fMRI data to show that sequential choice evokes a pattern of neural response consistent with a tracking of anticipated distribution of future reward, as expected in such a model. Thus, brain activity evoked at each decision point reflects the expected mean, variance, and skewness of possible payoffs, consistent with the idea that sequential choice evokes a prospective evaluation of both available strategies and possible outcomes.
Intracellular Recordings Reveal Novel Features of Neurons That Code Interaural Intensity Disparities in the Inferior Colliculus
Authors: Li Na , Gittelman Joshua X. , Pollak George D.
Published: October 2010

Many cells in the inferior colliculus (IC) are excited by contralateral and inhibited by ipsilateral stimulation and are thought to be important for sound localization. These excitatory–inhibitory (EI) cells comprise a diverse group, even though they exhibit a common binaural response property. Previous extracellular studies showed the diversity results from different circuits that generate the same EI property among the IC population, where some inherit the property from a lower nucleus, some are formedde novoin the IC, and others inherit EI features that are modified by inhibitory circuits. Here we evaluated the differential circuitry by recording inputs (postsynaptic potentials) and outputs (spikes) within vivowhole-cell recordings from the IC of awake Mexican free-tailed bats. We show that in a minority of EI cells, either they inherited their binaural property from a lower binaural nucleus or the EI property was created in the IC via inhibitory projections from the ipsilateral ear, features consistent with those observed in extracellular studies. However, in a majority of EI cells, ipsilateral signals evoked subthreshold EPSPs that behaved paradoxically in that EPSP amplitudes increased with intensity, even though binaural signals with the same ipsilateral intensities generated progressively greater spike suppressions. We propose circuitry that can account for the responses we observed and suggest that the ipsilaterally evoked EPSPs could influence the responsiveness of IC cells to dynamic signals with interaural intensity disparities that change over time, such as moving sound sources or multiple sounds that occur in complex acoustic environments.
Escitalopram Enhances the Association of Serotonin-1A Autoreceptors to Heteroreceptors in Anxiety Disorders
Authors: Hahn Andreas , Lanzenberger Rupert , Wadsak Wolfgang , Spindelegger Christoph , Moser UIrike , Mien Leonhard-Key , Mitterhauser Markus , Kasper Siegfried
Published: October 2010

Selective serotonin reuptake inhibitors (SSRIs) represent one of the most common treatment options in major depression and anxiety disorders. By blocking the serotonin transporter, SSRIs modulate serotonergic neurotransmission as well as the function of autoreceptors and heteroreceptors. However, treatment-induced changes on a network level primarily remain unknown. Thus, we evaluated the association between serotonin-1A (5-HT1A) autoreceptors and heteroreceptors before and after SSRIs. Twenty-one patients with anxiety disorders underwent positron emission tomography using [carbonyl-11C]WAY-100635 before and after 12 weeks of escitalopram treatment; 15 of them completed the study protocol. Additionally, 36 drug-naive healthy controls were measured once. The 5-HT1Areceptor binding potential (BPND) was quantified for the dorsal raphe nucleus (DRN) using a region-of-interest approach and for the entire brain by calculating parametric maps. Voxel-wise linear regression was applied between DRN autoreceptor and whole-brain heteroreceptor 5-HT1ABPND. Consistent with previous observations, healthy subjects showed widespread positive correlations of 5-HT1ABPNDbetween autoreceptors and heteroreceptors. Comparing patients before versus after escitalopram treatment revealed enhanced associations of autoreceptor-to-heteroreceptor 5-HT1ABPNDwithin the amygdala and hippocampus (R2= 0.21–0.28 vs 0.49–0.81;p< 0.05–0.001). In contrast, no significant SSRI-induced changes were found for correlations of heteroreceptor-to-heteroreceptor 5-HT1ABPNDbetween several limbic regions. This interregional approach suggests a treatment-induced reinforcement of the association of 5-HT1Abinding between autoreceptors and heteroreceptors specifically in areas involved in anxiety disorders. These findings provide complementary information about treatment effects on a network level and confirm the central role of the DRN as a prime regulatory area.
Serum Response Factor Promotes Resilience to Chronic Social Stress through the Induction of ΔFosB
Authors: Vialou Vincent , Maze Ian , Renthal William , LaPlant Quincey C. , Watts Emily L. , Mouzon Ezekiell , Ghose Subroto , Tamminga Carol A. , Nestler Eric J.
Published: October 2010

The molecular mechanisms underlying stress- and drug-induced neuronal adaptations are incompletely understood. One molecule implicated in such adaptations is ΔFosB, a transcription factor that accumulates in the rodent nucleus accumbens (NAc), a key brain reward region, in response to either chronic stress or repeated exposure to drugs of abuse. The upstream transcriptional mechanisms controlling ΔFosB induction by these environmental stimuli remain elusive. Here, we identify the activity-dependent transcription factor, serum response factor (SRF), as a novel upstream mediator of stress-, but not cocaine-, induced ΔFosB. SRF is downregulated in NAc of both depressed human patients and in mice chronically exposed to social defeat stress. This downregulation of SRF is absent in resilient animals. Through the use of inducible mutagenesis, we show that stress-mediated induction of ΔFosB, which occurs predominantly in resilient mice, is dependent on SRF expression in this brain region. Furthermore, NAc-specific genetic deletion of SRF promotes a variety of prodepressant- and proanxiety-like phenotypes and renders animals more sensitive to the deleterious effects of chronic stress. In contrast, we demonstrate that SRF does not play a role in ΔFosB accumulation in NAc in response to chronic cocaine exposure. Furthermore, NAc-specific knock-out of SRF has no effect on cocaine-induced behaviors, indicating that chronic social defeat stress and repeated cocaine exposure regulate ΔFosB accumulation and behavioral sensitivity through independent mechanisms.
Sleep Spindle Activity is Associated with the Integration of New Memories and Existing Knowledge
Authors: Tamminen Jakke , Payne Jessica D. , Stickgold Robert , Wamsley Erin J. , Gaskell M. Gareth
Published: October 2010

Sleep spindle activity has been associated with improvements in procedural and declarative memory. Here, for the first time, we looked at the role of spindles in the integration of newly learned information with existing knowledge, contrasting this with explicit recall of the new information. Two groups of participants learned novel spoken words (e.g., cathedruke) that overlapped phonologically with familiar words (e.g., cathedral). The sleep group was exposed to the novel words in the evening, followed by an initial test, a polysomnographically monitored night of sleep, and a second test in the morning. The wake group was exposed and initially tested in the morning and spent a retention interval of similar duration awake. Finally, both groups were tested a week later at the same circadian time to control for possible circadian effects. In the sleep group, participants recalled more words and recognized them faster after sleep, whereas in the wake group such changes were not observed until the final test 1 week later. Following acquisition of the novel words, recognition of the familiar words was slowed in both groups, but only after the retention interval, indicating that the novel words had been integrated into the mental lexicon following consolidation. Importantly, spindle activity was associated with overnight lexical integration in the sleep group, but not with gains in recall rate or recognition speed of the novel words themselves. Spindle activity appears to be particularly important for overnight integration of new memories with existing neocortical knowledge.
Effects of Synaptic Modulation on β-Amyloid, Synaptophysin, and Memory Performance in Alzheimer's Disease Transgenic Mice
Authors: Tampellini Davide , Capetillo-Zarate Estibaliz , Dumont Magali , Huang Zhenyong , Yu Fangmin , Lin Michael T. , Gouras Gunnar K.
Published: October 2010

Accumulation of β-amyloid (Aβ) and loss of synapses are hallmarks of Alzheimer's disease (AD). How synaptic activity relates to Aβ accumulation and loss of synapses is a current topic of major interest. Synaptic activation promotes Aβ secretion, and chronic reduction of synaptic activity reduced Aβ plaques in an AD transgenic mouse model. This suggested beneficial effects of reducing synaptic activity in AD. We now show that reduced synaptic activity causes detrimental effects on synapses and memory despite reducing plaques using two different models of chronic synaptic inhibition: deafferentation of the barrel cortex and administration of benzodiazepine. An interval of prolonged synaptic inhibition exacerbated loss of synaptophysin compared with synaptically more active brain in AD transgenic but not wild-type mice. Furthermore, an interval of benzodiazepine treatment, followed by a washout period, exacerbated memory impairment in AD transgenic mice. Exacerbation of synaptic and behavioral abnormalities occurred in the setting of reduced Aβ plaques but elevated intraneuronal Aβ immunoreactivity. These data support beneficial effects of synaptic activation on Aβ-related synaptic and behavioral impairment in AD.
Amyloid β-Protein Dimers Rapidly Form Stable Synaptotoxic Protofibrils
Authors: O'Nuallain Brian , Freir Darragh B. , Nicoll Andrew J. , Risse Emmanuel , Ferguson Neil , Herron Caroline E. , Collinge John , Walsh Dominic M.
Published: October 2010

Nonfibrillar, water-soluble low-molecular weight assemblies of the amyloid β-protein (Aβ) are believed to play an important role in Alzheimer's disease (AD). Aqueous extracts of human brain contain Aβ assemblies that migrate on SDS-polyacrylamide gels and elute from size exclusion as dimers (∼8 kDa) and can block long-term potentiation and impair memory consolidation in the rat. Such species are detected specifically and sensitively in extracts of Alzheimer brain suggesting that SDS-stable dimers may be the basic building blocks of AD-associated synaptotoxic assemblies. Consequently, understanding the structure and properties of Aβ dimers is of great interest. In the absence of sufficient brain-derived dimer to facilitate biophysical analysis, we generated synthetic dimers designed to mimic the natural species. For this, Aβ(1-40) containing cysteine in place of serine 26 was used to produce disulphide cross-linked dimer, (AβS26C)2. Such dimers had no detectable secondary structure, produced an analytical ultracentrifugation profile consistent for an ∼8.6 kDa protein, and had no effect on hippocampal long-term potentiation (LTP). However, (AβS26C)2aggregated more rapidly than either AβS26C or wild-type monomers and formed parastable β-sheet rich, thioflavin T-positive, protofibril-like assemblies. Whereas wild-type Aβ aggregated to form typical amyloid fibrils, the protofibril-like structures formed by (AβS26C)2persisted for prolonged periods and potently inhibited LTP in mouse hippocampus. These data support the idea that Aβ dimers may stabilize the formation of fibril intermediates by a process distinct from that available to Aβ monomer and that higher molecular weight prefibrillar assemblies are the proximate mediators of Aβ toxicity.
S-Nitrosylation of Cyclin-Dependent Kinase 5 (Cdk5) Regulates Its Kinase Activity and Dendrite Growth During Neuronal Development
Authors: Zhang Peng , Yu Pei-Chun , Tsang Anthony H. K. , Chen Yu , Fu Amy K. Y. , Fu Wing-Yu , Chung Kenny K. , Ip Nancy Y.
Published: October 2010

Precise regulation of cyclin-dependent kinase 5 (Cdk5), a member of the cyclin-dependent kinase family, is critical for proper neuronal development and functions. Cdk5 is activated through its association with the neuron-specific activator p35 or p39. Nonetheless, how its kinase activity is regulated in neurons is not well understood. In this study, we found that Cdk5 activity is regulated by S-nitrosylation, a post-translational modification of protein that affects a plethora of neuronal functions. S-nitrosylation of Cdk5 occurs at Cys83, which is one of the critical amino acids within the ATP-binding pocket of the kinase. Upon S-nitrosylation, Cdk5 exhibits reduced kinase activity, whereas mutation of Cys83 to Ala on Cdk5 renders the kinase refractory to such inhibition. Importantly, S-nitrosylated Cdk5 can be detected in the mouse brain, and blocking the S-nitrosylation of Cdk5 in cultured hippocampal neurons enhances dendritic growth and branching. Together, our findings reveal an important role of S-nitrosylation in regulating Cdk5 kinase activity and dendrite growth in neurons during development.
Nucleus Accumbens-Derived Glial Cell Line-Derived Neurotrophic Factor Is a Retrograde Enhancer of Dopaminergic Tone in the Mesocorticolimbic System
Authors: Wang Jun , Carnicella Sebastien , Ahmadiantehrani Somayeh , He Dao-Yao , Barak Segev , Kharazia Viktor , Ben Hamida Sami , Zapata Agustin , Shippenberg Toni S. , Ron Dorit
Published: October 2010

Spontaneous firing of ventral tegmental area (VTA) dopamine (DA) neurons provides ambient levels of DA in target areas such as the nucleus accumbens (NAc) and the prefrontal cortex (PFC). Here we report that the glial cell line-derived neurotrophic factor (GDNF), produced in one target region, the NAc, is retrogradely transported by DA neurons to the VTA where the growth factor positively regulates the spontaneous firing activity of both NAc- and PFC-projecting DA neurons in a mechanism that requires the activation of the mitogen-activated protein kinase (MAPK) pathway. We also show that the consequence of GDNF-mediated activation of the MAPK signaling cascade in the VTA is an increase in DA overflow in the NAc. Together, these results demonstrate that NAc-produced GDNF serves as a retrograde enhancer that upregulates the activity of the mesocorticolimbic DA system.
Control of Spatial and Feature-Based Attention in Frontoparietal Cortex
Authors: Greenberg Adam S. , Esterman Michael , Wilson Daryl , Serences John T. , Yantis Steven
Published: October 2010

Visual attention selects task-relevant information from scenes to help achieve behavioral goals. Attention can be deployed within multiple domains to select specific spatial locations, features, or objects. Recent evidence has shown that voluntary shifts of attention in multiple domains are consistently associated with transient increases in cortical activity in medial superior parietal lobule, suggesting that this may be the source of a domain-independent control signal that initiates the reconfiguration of attention. To investigate this hypothesis, we used fMRI to measure changes in cortical activation while human subjects shifted attention between spatial locations or between colors at a location. Univariate multiple regression analysis revealed a common, domain-independent transient signal [in posterior parietal cortex (PPC) and prefrontal cortex] time-locked to shifts of attention in both domains. However, multivariate pattern classification conducted on the cortical surface revealed that the spatiotemporal pattern of activity within PPC differed reliably for spatial and feature-based attention shifts. These results suggest that the posterior parietal cortex is a common hub for the control of attention shifts but contains subpopulations of neurons with domain-specific tuning for cognitive control.
Dados normativos para o teste de fluência verbal categoria animais em nosso meio
Authors: Brucki Sonia M. Dozzi , Malheiros Suzana M. Fleury , Okamoto Ivan H. , Bertolucci Paulo H. F.
Published: October 2010

OBJETIVOS: Avaliar o desempenho na fluência verbal em nossa população e verificar a influência da idade e escolaridade. MÉTODOS: Foram entrevistados 336 indivíduos sem queixas neurológicas ou psiquiátricas, através do Mini-Exame do Estado Mental (MEM) e geração de animais em um minuto. Para efeito comparativo e para verificação dos níveis de corte, foram examinados 65 indivíduos com quadro de perda cognitiva, acompanhados no ambulatório de Neurologia do Comportamento da EPM. RESULTADOS: Na população "normal" tivemos média de 13,84 animais por minuto. Para os grupos de escolaridade: 11,92, para analfabetos; 12,82, para indivíduos com até 4 anos incompletos; 13,45, para os de 4 a 8 anos incompletos; 15,88 para os com 8 ou mais anos de escolaridade. Houve diferença significante entre eles (p= 0,0001). Para os grupos etários, tivemos médias de: 13,79, para aqueles com idade inferior a 65 anos; 13.92 para os com idade igual ou superior a 65 anos (sem diferença estatística). Determinamos para esses grupos dois níveis de corte: 9 para indivíduos com até 8 anos de escolaridade com sensibilidade de 75 % para analfabetos, 100 % para baixa escolaridade, 87 % para média escolaridade; e especificidade de 79 % para analfabetos, 84 % para baixa escolaridade, 88 % para média escolaridade. Para o grupo de alta escolaridade o escore de corte foi de 13, com sensibilidade de 86 % e especificidade de 67 %. CONCLUSÃO: Devemos utilizar níveis diferenciados de corte no teste de fluência verbal, em nosso meio, considerando os efeitos da escolaridade sobre o desempenho neste teste.
Monitorização da pressão intracraniana como exame complementar no diagnóstico de morte encefálica: observação preliminar através do registro de dois casos
Authors: Agapejev Svetlana , Silva Pedro Paulo Thimoteo da , Zanini Marco Antonio , Piza Edmur Toledo
Published: October 2010

Estudou-se retrospectivamente a evolução clínica de dois pacientes, até sua falência cardíaca irreversível (FCI), submetidos à monitorização contínua da pressão intracraniana (PIC). O estudo detalhado desses traçados mostrou que, nos dois casos a PIC atingiu valores máximos 5 e 12 h antes de ocorrer diminuição na amplitude das ondas, observada 47 e 60 h pré-FCI. Essa diminução foi progressiva e tornou-se linear cerca de 30 h antes da FCI, em ambos os casos. O diagnóstico clínico de morte encefálica (ME) foi obtido 3 e 28 hs após a linearidade do traçado. Os autores sugerem que o diagnóstico de ME pode ser definido mais precocemente com o uso da monitorização da PIC desde que o paciente não esteja sob sedação, e salientam a necessidade de mais observações, em número maior de pacientes.
Resolution of syringomyelia in ten cases of "up-and-down Chiari malformation" after posterior fossa decompression
Authors: Silva José Alberto Gonçalves da , Melo Luiz Ricardo Santiago , Araújo Antônio Fernandes de , Santos Jr Adailton Arcanjo dos
Published: October 2010

The authors describe ten cases of syringomyelia without hindbrain herniation depicted by preoperative magnetic resonance imaging (MRI) in supine position. However, the herniation was observed in all cases during the operation with the patient in sitting position. The postoperative MRI revealed an intense reduction of the syrinx in all patients, as well as it was also observed a clinical amelioration in all cases. The surgical treatment was based on a large craniectomy with the patient in sitting position, tonsillectomy, large opening of the fourth ventricle and duraplasty with creation of a large cisterna magna.
The monitoring of hematopoietic stem cell transplant donors and recipients from endemic areas for malaria
Authors: Inoue Juliana , Machado Clarisse Martins , Lima Giselle Fernandes Maciel de Castro , Nascimento Maria de Jesus Costa , Colturato Vergílio Rensi , Di Santi Silvia Maria
Published: October 2010

Malaria is an unusual complication after hematopoietic stem cell transplantation in non-endemic countries. However, transplant candidates, recipients and donors living in endemic regions frequently report previous episodes of malaria. This fact could represent an important risk for immunosuppressed recipients that could develop severe malaria cases. We report a case of hematopoietic stem cell transplant (HSCT) in which the donor had a history of previous malaria, and close monitoring was performed before and after procedure by parasitological and molecular tests. The donor presented Plasmodium vivax in thick blood smears one month after transplant and was treated according to Brazilian Health Ministry guidelines. The polymerase chain reaction (PCR) was able to detect malaria infection in the donor one week earlier than thick blood film. Even without positive results, the recipient was pre-emptively treated with chloroquine in order to prevent the disease. We highlight the importance of monitoring recipients and donors in transplant procedures with the aim of reducing the risk of malaria transmission.
Gênero, ação e sistema: a reinvenção dos sujeitos
Authors: Hita Maria Gabriela
Published: October 2010

Após um exame de alguns problemas não resolvidos no feminismo analisam-se, a partir de uma perspectiva de gênero, dois importantes modelos teóricos da atualidade: o de Habermas e o de Luhmann, este visto como oferecendo uma perspectiva da "diferença". No final reflete-se sobre o tipo de políticas que resultaria de posições não mais limitadas a uma concepção rígida da questão da identidade.
Sobrepeso e obesidade em escolares brasileiros de sete a nove anos: dados do projeto Esporte Brasil
Authors: Pelegrini Andreia , Silva Diego Augusto S. , Petroski Edio Luiz , Gaya Adroaldo Cezar A.
Published: October 2010

OBJETIVO: Descrever a prevalência de sobrepeso e obesidade em escolares brasileiros de sete a nove anos e verificar a associação com as variáveis: sexo, idade e região geográfica. MÉTODOS: Estudo epidemiológico transversal conduzido em 2.913 escolares (1.478 do sexo masculino e 1.435 do feminino) com idade entre sete e nove anos. Como critério de diagnóstico de sobrepeso e obesidade foram utilizados os pontos de corte do índice de massa corpórea, propostos pela International Obesity Task Force. A comparação entre as proporções foi realizada mediante o teste qui-quadrado. As diferenças entre as proporções foram testadas por meio do teste de comparação entre duas proporções. RESULTADOS: A prevalência de sobrepeso e obesidade foi de 15,4 e 7,8% em meninos e meninas, respectivamente, com proporções similares entre sexo e idades. No sexo masculino, foi verificada associação do sobrepeso e obesidade apenas com região geográfica (p<0,001), com prevalências mais elevadas nas crianças da região Sul. No feminino, sobrepeso mais elevado foi observado nas crianças de sete anos da região Norte, enquanto a prevalência de obesidade foi maior nas crianças da região Sul. CONCLUSÕES: As crianças da região Sul apresentam maiores prevalências de sobrepeso e obesidade que aquelas das demais regiões do país. Os achados do presente estudo apontam uma tendência de aumento na prevalência de sobrepeso e obesidade na infância e corroboram os resultados encontrados em pesquisas mais abrangentes realizadas no Brasil.
Desnutrição energético-proteica grave durante a hospitalização: aspectos fisiopatológicos e terapêuticos
Authors: Lima Adriana Martins de , Gamallo Silvia Maria M. , Oliveira Fernanda Luisa C.
Published: October 2010

OBJETIVOS: Apresentar a conduta para o tratamento da desnutrição energético-proteica grave e os principais aspectos fisiopatológicos da doença. FONTES DE DADOS: Tomando como base o Manual da Organização Mundial da Saúde (OMS, 1999), realizou-se uma busca por trabalhos publicados em inglês, espanhol e português sobre o tratamento hospitalar de crianças com desnutrição grave, nas bases de dados Lilacs, Medline e SciELO, publicados nos últimos dez anos, utilizando-se as palavras-chave: desnutrição, criança, hospitalização, terapia nutricional, diretrizes, OMS. SÍNTESE DE DADOS: Foram abordadas as principais características fisiopatológicas da desnutrição grave e a conduta recomendada para o tratamento. Identificaram-se as principais complicações clínico-metabólicas, como a hipotermia, a hipoglicemia, a desidratação e as infecções recorrentes, além da má absorção e a fase de estabilização ou de recuperação do desnutrido grave. A compreensão de todos esses conceitos relacionados à fisiopatologia da desnutrição energético-proteica, associada ao adequado planejamento e execução da terapia nutricional, pode reduzir o risco de morbimortalidade em crianças com idade inferior a cinco anos. CONCLUSÕES: As diretrizes da OMS devem ser implantadas levando-se em consideração a realidade de cada região e a capacitação do profissional da saúde quanto ao conhecimento da complexidade e fisiopatologia da desnutrição energético-proteica grave, para adequado diagnóstico e tratamento. O sucesso do tratamento está associado ao cuidado e à atenção ao paciente.
Desenvolvimento de bebida láctea sabor morango utilizando diferentes níveis de iogurte e soro lácteo obtidos com leite de búfala
Authors: Caldeira Luciana Albuquerque , Ferrão Sibelli Passini Barbosa , Fernandes Sérgio Augusto De Albuquerque , Magnavita Ana Prudência Assis , Santos Tayse Dantas Rebouças
Published: October 2010

Este trabalho foi realizado com o objetivo de avaliar as características físico-químicas, sensoriais e microbiológicas de bebidas lácteas elaboradas com leite de búfala e diferentes níveis de iogurte e soro lácteo. Foram desenvolvidas cinco formulações à base de leite de búfala, soro de queijo tipo frescal e iogurte. Os tratamentos foram: T1=10% leite, 10% soro e 80% iogurte; T2=10% leite, 20% soro e 70% iogurte; T3=10% leite, 30% soro e 60% iogurte; T4=10% leite, 40% soro e 50% iogurte; e T5=10% leite, 50% soro e 40% iogurte. Para o leite e soro, foram determinadas acidez titulável (°D), densidade a 15°C, gordura, EST e ESD. As bebidas lácteas foram avaliadas quanto aos parâmetros: pH, acidez titulável, gordura, proteína, viscosidade, cor (CIEL*a*b*), teste de aceitação sensorial com escala hedônica de cinco pontos, ordenação da preferência, enumeração de coliformes a 35 e 45°C e contagem de microrganismos mesófilos aeróbios. Os resultados obtidos, submetidos ao teste de ANOVA e teste de médias com nível de significância a 5%, revelaram que os níveis de soro influenciaram os valores de pH, acidez, gordura, proteína, viscosidade e L* das bebidas lácteas, enquanto as coordenadas de cromaticidade a* e b* não sofreram influência. As formulações com 10 e 20% de soro foram as mais aceitas no teste de aceitação sensorial, bem como na preferência pelos julgadores.
Influência da adição de iodeto de potássio e citrato de sódio na qualidade do sêmen de pacu (Piaractus mesopotamicus - Holmberg, 1887)
Authors: Maria Alexandre Nízio , Murgas Luis David Solis , Silva Márcia Oliveira Barbosa , Miliorini Alécio B. , Franciscatto Renan T. , Logato Priscila Vieira Rosa
Published: October 2010

Atualmente, tem-se dado maior atenção ao desenvolvimento de tecnologias para estocagem de sêmen de peixes em curto prazo, por dias ou semanas, utilizando diluentes de sêmen que não ativem a motilidade espermática. Essa técnica é indicada em piscicultura para facilitar a reprodução artificial ou aumentar sua eficiência. Conduziu-se este trabalho com o objetivo de verificar o efeito do diluidor BTS (Beltsville Thawing Solution - MINITUB®) na qualidade do sêmen de pacu, após a coleta, enriquecido com iodeto de potássio e com citrato de sódio. Foram utilizados seis reprodutores de pacu (Piaractus mesopotamicus) submetidos à indução hormonal e liberação dos gametas, manualmente. O sêmen coletado de cada macho foi dividido em três frações, as quais receberam diluição (1:3) com o diluidor 1 (BTS 5% + iodeto de potássio 0,16%), diluidor 2 (BTS 5% + citrato de sódio 1,28%) e uma fração não diluída (controle). A ativação espermática foi realizada com água destilada, e, a seguir, foram avaliadas as taxas e duração da motilidade espermática, cujos valores médios respectivos foram de 95,00 ± 3,16% e 486,83 ± 314,55 segundos para o sêmen in natura, 80,00 ± 9,49% e 221,50 ± 207,89 segundos para o sêmen com o diluidor 1 e 80,00 ± 11,40% e 320,66 ± 181,14 segundos para o sêmen no diluidor 2. Em seguida, foram coletadas amostras para a avaliação da concentração espermática, que obteve um valor médio de 13,89 ± 1,26 x 10(9)/mL. Pelas análises estatísticas, verificou-se que não houve diferença significativa na duração da motilidade (P>0,05) entre o sêmen “in natura” e os diluidores 1 e 2. A motilidade espermática foi estatisticamente melhor (P<0,05) no sêmen in natura, quando comparada com os diluidores 1 e 2. Não houve diferença entre os dois diluidores para esse parâmetro. Conclui-se, assim, que os diluidores reduziram a motilidade espermática, sem entretanto, afetar a duração da motilidade, podendo ser utilizado na conservação do sêmen dessa espécie, desde que sua osmolaridade seja aumentada. Há necessidade de mais pesquisas para se avaliar a eficiência desses diluidores várias horas após resfriamento.
Analise comparativa da organização e metodologia da seleção clonal da videira na frança e Brasil
Authors: Regina Murillo de Albuquerque
Published: October 2010

A origem policlonal da videira, associando-se sua sensibilidade à ocorrência de mutações somáticas espontâneas, faz com que exista uma grande variabilidade genética no interior de uma mesma cultivar dessa espécie, permitindo, por meio da seleção clonal, a obtenção de descendências que atendam aos objetivos específicos de produção, como produtividade e qualidade. Em razão da ocorrência generalizada de viroses na maioria dos vinhedos, a seleção clonal da videira é obrigatoriamente genética e sanitária, devendo obedecer a um certo número de etapas para que os clones selecionados possam atender aos requisitos qualitativos desejados. Na França, o programa de seleção clonal da videira data dos anos 60, e já permitiu a obtenção de centenas de clones de cultivares porta-enxerto e cultivares de vinho e mesa. Com este trabalho objetivou-se ilustrar as diferentes etapas e organização da seleção clonal da videira na França.
Enraizamento adventício de estacas apicais de figueira e desenvolvimento inicial das plantas no campo
Authors: Pio Rafael , Ramos José Darlan , Chalfun Nilton Nagib Jorge , Coelho Juliana Helena Carvalho , Gontijo Tiago Chaltein Almeida , Carrijo Edney Paulo , Villa Fabíola
Published: October 2010

Apesar de a propagação vegetativa da figueira ser praticada há muito tempo, estudos para definir novas metodologias são importantes, notadamente com o uso de estacas apicais e reguladores vegetais. Objetivou-se com este trabalho verificar o comportamento de plantas de figueira no campo, previamente enraizadas, com o uso de sacarose diluída em soluções de AIB. Estacas lenhosas e lisas da porção apical de figueira com 20 cm de comprimento foram imersas em soluções sem e com sacarose a 2%, em AIB (0, 1000, 2000, 3000 e 4000 mg.L-1), por 5 segundos. Após as imersões, as estacas foram acondicionadas em recipientes de 26 x 14 cm preenchidos com substrato à base de terra e areia (2:1 v/v) e transferidas para câmara de nebulização com sistema de irrigação e temperatura controlada. Após 60 dias, realizou-se a primeira avaliação em atributos referentes ao sistema radicular e parte aérea. Uma outra parte das plantas foi transferida para recipientes constituídos de plástico rígido com capacidade de 5 litros, preenchidos com substratos constituídos de terra e esterco de curral (3:1 v/v), em campo. Após 120 dias, constatou-se que estacas tratadas e não tratadas com sacarose e AIB na fase de enraizamento possuem comportamentos semelhantes no campo, havendo necessidade do tratamento de estacas com AIB somente para aumentar a porcentagem de estacas enraizadas.
Práticas escolares e desempenho acadêmico de alunos com TDAH
Authors: Reis Maria das Graças Faustino , Camargo Dulce Maria Pompêo de
Published: October 2010

Este artigo reporta resultados de trabalho de pesquisa que tem como objeto o estudo crítico e aprofundado sobre o TDAH (Transtorno de Déficit de Atenção/Hiperatividade) nos cursos de formação de professores no Ensino Superior, sob as suas variadas dimensões - social, cultural, pedagógica, biológica. A investigação focalizou cinco adultos com diagnóstico de TDAH. A metodologia utilizada foi o Estudo de Caso, desenvolvido a partir da História Oral como fonte de coleta de dados. Os resultados obtidos sugerem que o estudo proposto na pesquisa pode contribuir significativamente para o professor conhecer os determinantes do desempenho escolar de alunos com o transtorno, bem como orientá-lo na busca de parceria com outros profissionais - médicos e psicólogos, por exemplo - quando esta se fizer necessária.