bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of spatial variation in surface relaxivity on nuclear magnetic resonance relaxation rates
Authors: Keating Kristina , Knight Rosemary
Published: August 2012

Nuclear magnetic resonance (NMR) relaxation measurements are sensitive to the physiochemical environment of water in saturated porous media and can provide information about the properties of geologic material. Interpretation of NMR data typically relies on three assumptions: that pores within the geologic material are effectively isolated such that the diffusion of a proton between pores is limited (i.e., there is weak coupling); that relaxation occurs in the fast-diffusion regime; and that surface relaxivity [Formula: see text] is uniform throughout the measured volume. We investigated the effect of spatial variation in [Formula: see text] on the NMR relaxation measurement and evaluated two equations relating [Formula: see text] to the NMR relaxation rate for samples containing two types of surfaces, each with a different surface relaxivity. One equation was valid when there is weak diffusional coupling between pores, the other is valid when there is strong diffusional coupling. We prepared a suite of samples composed of quartz sand and an iron-coated quartz sand. NMR relaxation occurred in two distinct regions: the weak- and strong-coupling regions. In the weak-coupling region, the equation did not accurately represent the relationship between the two [Formula: see text] values and the NMR relaxation rate, suggesting that further research is required to understand the effect of spatially variable [Formula: see text] in this relaxation region. In the strong-coupling region, the equation accurately represented the relationship between the two values of [Formula: see text] and the NMR relaxation rate. The results from these laboratory experiments represented a first step towards accounting for spatial variability in [Formula: see text] in the interpretation of NMR data.
Obesity and psychotic disorders: uncovering common mechanisms through metabolomics
Authors: Orešič Matej
Published: August 2012

Primary obesity and psychotic disorders are similar with respect to the associated changes in energy balance and co-morbidities, including metabolic syndrome. Such similarities do not necessarily demonstrate causal links, but instead suggest that specific causes of and metabolic disturbances associated with obesity play a pathogenic role in the development of co-morbid disorders, potentially even before obesity develops. Metabolomics – the systematic study of metabolites, which are small molecules generated by the process of metabolism – has been important in elucidating the pathways underlying obesity-associated co-morbidities. This review covers how recent metabolomic studies have advanced biomarker discovery and the elucidation of mechanisms underlying obesity and its co-morbidities, with a specific focus on metabolic syndrome and psychotic disorders. The importance of identifying metabolic markers of disease-associated intermediate phenotypes – traits modulated but not encoded by the DNA sequence – is emphasized. Such markers would be applicable as diagnostic tools in a personalized healthcare setting and might also open up novel therapeutic avenues.
Brain–gut–adipose-tissue communication pathways at a glance
Authors: Yi Chun-Xia , Tschöp Matthias H.
Published: August 2012

One of the ‘side effects’ of our modern lifestyle is a range of metabolic diseases: the incidence of obesity, type 2 diabetes and associated cardiovascular diseases has grown to pandemic proportions. This increase, which shows no sign of reversing course, has occurred despite education and new treatment options, and is largely due to a lack of knowledge about the precise pathology and etiology of metabolic disorders. Accumulating evidence suggests that the communication pathways linking the brain, gut and adipose tissue might be promising intervention points for metabolic disorders. To maintain energy homeostasis, the brain must tightly monitor the peripheral energy state. This monitoring is also extremely important for the brain’s survival, because the brain does not store energy but depends solely on a continuous supply of nutrients from the general circulation. Two major groups of metabolic inputs inform the brain about the peripheral energy state: short-term signals produced by the gut system and long-term signals produced by adipose tissue. After central integration of these inputs, the brain generates neuronal and hormonal outputs to balance energy intake with expenditure.

Miscommunication between the gut, brain and adipose tissue, or the degradation of input signals once inside the brain, lead to the brain misunderstanding the peripheral energy state. Under certain circumstances, the brain responds to this miscommunication by increasing energy intake and production, eventually causing metabolic disorders. This poster article overviews current knowledge about communication pathways between the brain, gut and adipose tissue, and discusses potential research directions that might lead to a better understanding of the mechanisms underlying metabolic disorders.
Fasting, feasting and the glutamatergic synapse
Authors: Ghose Piya
Published: August 2012

Summary and comment on a recent Neuron paper entitled ‘Fasting activation of AgRP neurons requires NMDA receptors and involves spinogenesis and increased excitatory tone’ (Liu et al., 2012).
A stingless bee can use visual odometry to estimate both height and distance
Authors: Eckles M. A. , Roubik D. W. , Nieh J. C.
Published: August 2012

Bees move and forage within three dimensions and rely heavily on vision for navigation. The use of vision-based odometry has been studied extensively in horizontal distance measurement, but not vertical distance measurement. The honey bee Apis mellifera and the stingless bee Melipona seminigra measure distance visually using optic flow–movement of images as they pass across the retina. The honey bees gauge height using image motion in the ventral visual field. The stingless bees forage at different tropical forest canopy levels, ranging up to 40 m at our site. Thus, estimating height would be advantageous. We provide the first evidence that the stingless bee Melipona panamica utilizes optic flow information to gauge not only distance traveled but also height above ground, by processing information primarily from the lateral visual field. After training bees to forage at a set height in a vertical tunnel lined with black and white stripes, we observed foragers that explored a new tunnel with no feeder. In a new tunnel, bees searched at the same height they were trained to. In a narrower tunnel, bees experienced more image motion and significantly lowered their search height. In a wider tunnel, bees experienced less image motion and searched at significantly greater heights. In a tunnel without optic cues, bees were disoriented and searched at random heights. A horizontal tunnel testing these variables similarly affected foraging, but bees exhibited less precision (greater variance in search positions). Accurately gauging flight height above ground may be crucial for this species and others that compete for resources located at heights ranging from ground level to the high tropical forest canopies.
Use of 4-mg/kg/24-Hour Empiric Aminoglycoside dosing in Preoperative Neonates with Congenital Heart Disease
Authors: Moffett Brady S , Rossano Joseph W
Published: August 2012

BACKGROUND:

Empiric dosing of gentamicin has not been evaluated in critically ill neonates with unrepaired congenital heart disease (CHD). Many factors may alter gentamicin pharmacokinetics in this patient population and there are few data describing gentamicin dosing regimens in this patient population.

OBJECTIVE:

To determine whether an empiric gentamicin dosing regimen for neonates achieves acceptable serum trough concentrations in neonatal patients with unrepaired CHD receiving alprostadil.

METHODS:

Term neonates with unrepaired CHD who received gentamicin for empiric treatment of sepsis were identified over a 3-year period. Patients were included if they received gentamicin 4 mg/kg/dose every 24 hours, were receiving alprostadil for maintenance of a patent ductus arteriosus, and had at least one gentamicin serum trough concentration determined. Patients were evaluated to determine whether they achieved a serum trough concentration of <1 mg/L, and differences in patient characteristics were noted for those who achieved an appropriate trough concentration and those who did not.

RESULTS:

Twenty-eight patients met study criteria, and 22% of patients had a trough gentamicin concentration of <1 mg/L at a mean (SD) time of 23.6 (0.3) hours after a dose. Few statistically significant differences in patient characteristics were noted for those who achieved an appropriate serum trough concentration and those who did not, and included Apgar scores at 1 minute and later day of life at admission.

CONCLUSIONS:

Current empiric gentamicin dosing regimens may not be appropriate for critically ill neonates with unrepaired CHD. Routine serum concentration monitoring may be warranted in this population.
Extracellular Alpha-Synuclein Oligomers Modulate Synaptic Transmission and Impair LTP Via NMDA-Receptor Activation
Authors: Diógenes Maria José , Dias Raquel B. , Rombo Diogo M. , Vicente Miranda Hugo , Maiolino Francesca , Guerreiro Patrícia , Näsström Thomas , Franquelim Henri G. , Oliveira Luís M.A. , Castanho Miguel A.R.B. , Lannfelt Lars , Bergström Joakim , Ingelsson Martin , Quintas Alexandre , Sebastião Ana M. , Lopes Luísa V. , Outeiro Tiago Fleming
Published: August 2012

Parkinson's disease (PD) is the most common representative of a group of disorders known as synucleinopathies, in which misfolding and aggregation of α-synuclein (a-syn) in various brain regions is the major pathological hallmark. Indeed, the motor symptoms in PD are caused by a heterogeneous degeneration of brain neurons not only in substantia nigra pars compacta but also in other extrastriatal areas of the brain. In addition to the well known motor dysfunction in PD patients, cognitive deficits and memory impairment are also an important part of the disorder, probably due to disruption of synaptic transmission and plasticity in extrastriatal areas, including the hippocampus.

Here, we investigated the impact of a-syn aggregation on AMPA and NMDA receptor-mediated rat hippocampal (CA3-CA1) synaptic transmission and long-term potentiation (LTP), the neurophysiological basis for learning and memory. Our data show that prolonged exposure to a-syn oligomers, but not monomers or fibrils, increases basal synaptic transmission through NMDA receptor activation, triggering enhanced contribution of calcium-permeable AMPA receptors. Slices treated with a-syn oligomers were unable to respond with further potentiation to theta-burst stimulation, leading to impaired LTP. Prior delivery of a low-frequency train reinstated the ability to express LTP, implying that exposure to a-syn oligomers drives the increase of glutamatergic synaptic transmission, preventing further potentiation by physiological stimuli.

Our novel findings provide mechanistic insight on how a-syn oligomers may trigger neuronal dysfunction and toxicity in PD and other synucleinopathies.
Spinal and Pontine Relay Pathways Mediating Respiratory Rhythm Entrainment by Limb Proprioceptive Inputs in the Neonatal Rat
Authors: Giraudin Aurore , Le Bon-Jégo Morgane , Cabirol Marie-Jeanne , Simmers John , Morin Didier
Published: August 2012

The coordination of locomotion and respiration is widespread among mammals, although the underlying neural mechanisms are still only partially understood. It was previously found in neonatal rat that cyclic electrical stimulation of spinal cervical and lumbar dorsal roots (DRs) can fully entrain (1:1 coupling) spontaneous respiratory activity expressed by the isolated brainstem/spinal cord. Here, we used a variety of preparations to determine the type of spinal sensory inputs responsible for this respiratory rhythm entrainment, and to establish the extent to which limb movement-activated feedback influences the medullary respiratory networks via direct or relayed ascending pathways. Duringin vivooverground locomotion, respiratory rhythm slowed and became coupled 1:1 with locomotion. In hindlimb-attached semi-isolated preparations, passive flexion–extension movements applied to a single hindlimb led to entrainment of fictive respiratory rhythmicity recorded in phrenic motoneurons, indicating that the recruitment of limb proprioceptive afferents could participate in the locomotor-respiratory coupling. Furthermore, in correspondence with the regionalization of spinal locomotor rhythm-generating circuitry, the stimulation of DRs at different segmental levels in isolated preparations revealed that cervical and lumbosacral proprioceptive inputs are more effective in this entraining influence than thoracic afferent pathways. Finally, blocking spinal synaptic transmission and using a combination of electrophysiology, calcium imaging and specific brainstem lesioning indicated that the ascending entraining signals from the cervical or lumbar limb afferents are transmitted across first-order synapses, probably monosynaptic, in the spinal cord. They are then conveyed to the brainstem respiratory centers via a brainstem pontine relay located in the parabrachial/Kölliker-Fuse nuclear complex.
Evidence for Hyperbolic Temporal Discounting of Reward in Control of Movements
Authors: Haith Adrian M. , Reppert Thomas R. , Shadmehr Reza
Published: August 2012

Suppose that the purpose of a movement is to place the body in a more rewarding state. In this framework, slower movements may increase accuracy and therefore improve the probability of acquiring reward, but the longer durations of slow movements produce devaluation of reward. Here we hypothesize that the brain decides the vigor of a movement (duration and velocity) based on the expected discounted reward associated with that movement. We begin by showing that durations of saccades of varying amplitude can be accurately predicted by a model in which motor commands maximize expected discounted reward. This result suggests that reward is temporally discounted even in timescales of tens of milliseconds. One interpretation of temporal discounting is that the true objective of the brain is to maximize the rate of reward—which is equivalent to a specific form of hyperbolic discounting. A consequence of this idea is that the vigor of saccades should change as one alters the intertrial intervals between movements. We find experimentally that in healthy humans, as intertrial intervals are varied, saccade peak velocities and durations change on a trial-by-trial basis precisely as predicted by a model in which the objective is to maximize the rate of reward. Our results are inconsistent with theories in which reward is discounted exponentially. We suggest that there exists a single cost, rate of reward, which provides a unifying principle that may govern control of movements in timescales of milliseconds, as well as decision making in timescales of seconds to years.
Differential Expression and Pharmacology of Native P2X Receptors in Rat and Primate Sensory Neurons
Authors: Serrano Alexandre , Mo Gary , Grant Rebecca , Paré Michel , O'Donnell Dajan , Yu Xiao Hong , Tomaszewski Miroslaw J. , Perkins Martin N. , Séguéla Philippe , Cao Chang Qing
Published: August 2012

Evidence suggesting the involvement of P2X2 and P2X3 in chronic pain has been obtained mostly from rodent models. Here we show that rodents may be poor predictors of P2X3 pharmacology in human. We demonstrate that monkey and human dorsal root ganglion (DRG) neurons do not express appreciable levels of P2X2 subunit, contrary to rat sensory neurons. Additionally, we report functional P2X3 activity in monkey DRG neurons and confirm the absence of functional P2X2/3 receptors. Interestingly, native P2X3 receptors in rat and monkey DRGs show similar agonist potency, but different antagonist potencies for TNP-ATP [2-O-(2,4,6-trinitrophenyl)-ATP] and RO51. This unexpected difference in antagonist potency was confirmed by comparing rat and human P2X3 receptors in HEK293 cells. Mutagenesis studies reveal that two extracellular residues, A197 and T202, are synergistically responsible for the potency drop in primate P2X3 receptors. These results uncover species-specific P2X3 pharmacology and identify key mechanisms impacting the translatability of potential analgesics targeting P2X3 receptors.
Netrin-1 Attracts Axons through FAK-Dependent Mechanotransduction
Authors: Moore Simon W. , Zhang Xian , Lynch Christopher D. , Sheetz Michael P.
Published: August 2012

The mechanism by which extracellular cues influence intracellular biochemical cascades that guide axons is important, yet poorly understood. Because of the mechanical nature of axon extension, we explored whether the physical interactions of growth cones with their guidance cues might be involved. In the context of mouse spinal commissural neuron axon attraction to netrin-1, we found that mechanical attachment of netrin-1 to the substrate was required for axon outgrowth, growth cone expansion, axon attraction and phosphorylation of focal adhesion kinase (FAK) and Crk-associated substrate (CAS). Myosin II activity was necessary for traction forces >30 pN on netrin-1. Interestingly, while these myosin II-dependent forces on netrin-1 substrates or beads were needed to increase the kinase activity and phosphorylation of FAK, they were not necessary for netrin-1 to increase CAS phosphorylation. When FAK kinase activity was inhibited, the growth cone's ability to recruit additional adhesions and to generate forces >60 pN on netrin-1 was disrupted. Together, these findings demonstrate an important role for mechanotransduction during chemoattraction to netrin-1 and that mechanical activation of FAK reinforces interactions with netrin-1 allowing greater forces to be exerted.
Organotypic Coculture Preparation for the Study of Developmental Synapse Elimination in Mammalian Brain
Authors: Uesaka Naofumi , Mikuni Takayasu , Hashimoto Kouichi , Hirai Hirokazu , Sakimura Kenji , Kano Masanobu
Published: August 2012

We developed an organotypic coculture preparation allowing fast and efficient identification of molecules that regulate developmental synapse elimination in the mammalian brain. This coculture consists of a cerebellar slice obtained from rat or mouse at postnatal day 9 (P9) or P10 and a medullary explant containing the inferior olive dissected from rat at embryonic day 15. We verified that climbing fibers (CFs), the axons of inferior olivary neurons, formed functional synapses onto Purkinje cells (PCs) in the cerebellum of cocultures. PCs were initially reinnervated by multiple CFs with similar strengths. Surplus CFs were eliminated subsequently, and the remaining CFs became stronger. These changes are similar to those occurring in developing cerebellumin vivo. Importantly, the changes in CF innervations in cocultures involved the same molecules required for CF synapse eliminationin vivo, including NMDA receptor, type 1 metabotropic glutamate receptor and glutamate receptor δ2 (GluRδ2). We demonstrate that gain- and loss-of-function analyses can be efficiently performed by lentiviral-mediated overexpression and RNAi-induced knockdown of GluRδ2. Using this approach, we identified neuroligin-2 as a novel molecule that promotes CF synapse elimination in postsynaptic PCs. Thus, our coculture preparation will greatly facilitate the elucidation of molecular mechanisms of synapse elimination.
TwoDrosophilaDEG/ENaC Channel Subunits Have Distinct Functions in Gustatory Neurons That Activate Male Courtship
Authors: Liu Tong , Starostina Elena , Vijayan Vinoy , Pikielny Claudio W.
Published: August 2012

Trimeric sodium channels of the DEG/ENaC family have important roles in neurons, but the specific functions of different subunits present in heteromeric channels are poorly understood. We previously reported that theDrosophilaDEG/ENaC subunit Ppk25 is essential in a small subset of gustatory neurons for activation of male courtship behavior, likely through detection of female pheromones. Here we show that, like mutations inppk25, mutations in anotherDrosophilaDEG/ENaC subunit gene,nope, specifically impair male courtship of females.noperegulatory sequences drive reporter gene expression in gustatory neurons of the labellum wings, and legs, including all gustatory neurons in whichppk25function is required for male courtship of females. In addition, gustatory-specific knockdown ofnopeimpairs male courtship. Further, the impaired courtship response ofnopemutant males to females is rescued by targeted expression ofnopein the subset of gustatory neurons in whichppk25functions. However,nopeandppk25have nonredundant functions, as targeted expression ofppk25does not compensate for the lack ofnopeand vice versa. Moreover, Nope and Ppk25 form specific complexes when coexpressed in cultured cells. Together, these data indicate that the Nope and Ppk25 polypeptides have specific, nonredundant functions in a subset of gustatory neurons required for activation of male courtship in response to females, and suggest the hypothesis that Nope and Ppk25 function as subunits of a heteromeric DEG/ENaC channel required for gustatory detection of female pheromones.
Dynamic Modulation of Cerebellar Excitability for Abrupt, But Not Gradual, Visuomotor Adaptation
Authors: Schlerf John E. , Galea Joseph M. , Bastian Amy J. , Celnik Pablo A.
Published: August 2012

The cerebellum is critically important for error-driven adaptive motor learning, as evidenced by the fact that cerebellar patients do not adapt well to sudden predictable perturbations. However, recent work has shown that cerebellar patients adapt much better if the perturbation is gradually introduced. Here we explore physiological mechanisms that underlie this distinction between abrupt and gradual motor adaptation in humans. We used transcranial magnetic stimulation to evaluate whether neural mechanisms within the cerebellum contribute to either process during a visuomotor reach adaptation. When a visuomotor rotation was introduced abruptly, cerebellar excitability changed early in learning and approached baseline levels near the end of the adaptation block. However, we observed no modulation of cerebellar excitability when we presented the visuomotor rotation gradually during learning. Similarly, we did not observe cerebellar modulation during trial-by-trial adaptation to random visuomotor displacements or during reaches without perturbations. This suggests that the cerebellum is most active during the early phases of adaptation when large perturbations are successfully compensated.
Projection Neurons in Lamina III of the Rat Spinal Cord Are Selectively Innervated by Local Dynorphin-Containing Excitatory Neurons
Authors: Baseer Najma , Polgár Erika , Watanabe Masahiko , Furuta Takahiro , Kaneko Takeshi , Todd Andrew J.
Published: August 2012

Large projection neurons in lamina III of the rat spinal cord that express the neurokinin 1 receptor are densely innervated by peptidergic primary afferent nociceptors and more sparsely by low-threshold myelinated afferents. However, we know little about their input from other glutamatergic neurons. Here we show that these cells receive numerous contacts from nonprimary boutons that express the vesicular glutamate transporter 2 (VGLUT2), and form asymmetrical synapses on their dendrites and cell bodies. These synapses are significantly smaller than those formed by peptidergic afferents, but provide a substantial proportion of the glutamatergic synapses that the cells receive (over a third of those in laminae I–II and half of those in deeper laminae). Surprisingly, although the dynorphin precursor preprodynorphin (PPD) was only present in 4–7% of VGLUT2 boutons in laminae I–IV, it was found in 58% of the VGLUT2 boutons that contacted these cells. This indicates a highly selective targeting of the lamina III projection cells by glutamatergic neurons that express PPD, and these are likely to correspond to local neurons (interneurons and possibly projection cells). Since many PPD-expressing dorsal horn neurons respond to noxious stimulation, this suggests that the lamina III projection cells receive powerful monosynaptic and polysynaptic nociceptive input. Excitatory interneurons in the dorsal horn have been shown to possessIAcurrents, which limit their excitability and can underlie a form of activity-dependent intrinsic plasticity. It is therefore likely that polysynaptic inputs to the lamina III projection neurons are recruited during the development of chronic pain states.
PICK1 Mediates Transient Synaptic Expression of GluA2-Lacking AMPA Receptors during Glycine-Induced AMPA Receptor Trafficking
Authors: Jaafari Nadia , Henley Jeremy M. , Hanley Jonathan G.
Published: August 2012

The number and subunit composition of postsynaptic AMPA receptors (AMPARs) is a key determinant of synaptic transmission. The vast majority of AMPARs contain GluA2 subunit, which renders the channel impermeable to calcium. However, a small proportion are GluA2 lacking and therefore calcium permeable (CP-AMPARs). It has been proposed recently that long-term potentiation (LTP) involves not only an increase in the total number of AMPARs at the synapse but also a transient switch to CP-AMPARs in the first few minutes after LTP induction. The molecular mechanisms that underlie this switch to CP-AMPARs and the subsequent switch back to calcium-impermeable AMPARs are unknown. Here, we show that endogenous GluA1 is rapidly inserted at the synaptic plasma membrane of rat hippocampal neurons immediately after stimulation with elevated glycine, a treatment known to induce LTP. In contrast, GluA2 is restricted from trafficking to the cell surface by a glycine-induced increase in PICK1–GluA2 binding on endosomal compartments. Between 5 and 20 min after stimulus, activation of CP-AMPARs triggers a release of GluA2 from PICK1, allowing GluA2-containing AMPARs to traffic to the synaptic plasma membrane. These results define a PICK1-dependent mechanism that underlies transient alterations in the subunit composition and calcium permeability of synaptic AMPARs that is important during the early phase after stimulation with glycine and therefore is likely to be important during the expression of LTP.
Challenging New Conservative Regimes in South Korea and Taiwan
Authors: Ho Ming-sho , Hong Chen-Shuo
Published: August 2012

This article compares anti-American beef politics in South Korea (2008) and Taiwan (2009) to solve the puzzle of why two similar social protests resulted in dissimilar outcomes. Given the highly comparable political contexts of conservative ascendancy, we argue that cultural factors determined the movement trajectories. The presence of anti-Americanism and the centrality of beef in the national diet produced a strong anti-government movement in Korea but not in Taiwan.
Structural and functional characterizations of activin type 2B receptor (acvr2b) ortholog from the marine fish, gilthead sea bream, Sparus aurata: evidence for gene duplication of acvr2b in fish
Authors: Funkenstein Bruria , Krol Ekaterina , Esterin Elena , Kim Yong-soo
Published: August 2012

Myostatin (MSTN), a negative regulator of muscle growth and a member of the transforming growth factor-β superfamily, can bind the two activin type 2 receptors (ACVR2). It has been previously shown that WT mice injected with ACVR2B extracellular domain (ACVR2B-ECD) had higher muscle mass. Likewise, fish larvae immersed inPichia pastorisculture supernatant, containing goldfish Acvr2b-ECD, showed enhanced larval growth. However, it is not clear whether fish Mstn1 and Mstn2 signal through the same receptor and whether fish express more than oneacvr2bgene. In the current study, three cDNAs encodingacvr2b(saacvr2b-1, saacvr2b-2a, and saacvr2b-2b) were cloned from gilthead sea bream. All three contain the short extracellular binding domain, a short transmembrane region, and a conserved catalytic domain of serine/threonine protein kinase. Bioinformatics analysis provided evidence for the existence of twoacvr2bgenes (acvr2b-1 andacvr2b-2) in several other fish species as well, probably as a result of gene or genome duplication. The two isoforms differ in their amino acid sequences. The direct inhibitory effect of Acvr2b-ECD on Mstn activity was testedin vitro. The saAcvr2b-1-ECD was expressed in the yeastP. pastoris. Evidence is provided for N-glycosylation of Acvr2b-1-ECD. The affinity-purified Acvr2b-1-ECD inhibited recombinant mouse/rat/human mature MSTN activity when determinedin vitrousing the CAGA-luciferase assay in A204 cells. A lower inhibitory activity was obtained when unprocessed purified, furin-digested, and activated saMstn1 was used. Results of this study demonstrate for the first time the existence of twoacvr2bgenes in fish. In addition, the study shows that bioactive fish Acvr2b-ECD can be produced fromP. pastoris.
Preparation and Photocatalytic Activity Study of p-CuO/n-ZnO composites
Authors: Sapkota Bedanga B , Mishra Sanjay R
Published: August 2012

In this paper, efficacy of p-n junction p-CuO/n-ZnO composite is assessed as a potential photocatalyst by monitoring degradation of methylene blue (MB) in the presence of UV light. The p-n junction photocatalyst, p-CuO/n-ZnO, was prepared by ball milling of ZnO and CuO in water. The structural properties of p-CuO/n-ZnO composite were characterized by x-ray diffractometer and surface charge properties via zeta potential measurement. The degradation of MB in the presence of composite powder was monitored via UV-vis spectrometer. Various studies affecting the degradation rate of MB were conducted as a function of weight fraction of CuO in the composite and ball milling time. The highest degradation rate of MB was achieved in CuO (10 Wt.%)/ZnO for which high negative zeta potential was recorded. The MB degradation efficiency was found to decrease with the samples ball milled for time longer than 12 hours due to increased agglomeration of particles. The mechanisms that influence the photocatalytic activity of p-CuO/n-ZnO are discussed based on the p-n junction principle.
Enhanced response characteristics of SnO2-ZnO hetrostructures loaded with nanoscale catalyst clusters for methane gas detection
Authors: Haridas Divya , Gupta Vinay
Published: August 2012

Methane is an important explosive gas, used extensively at the domestic and industrial sites. It is the main constituent of natural gas, which is the main fuel supplied to homes and industries including automobiles. Detection of trace level of methane gas is very important to avoid any accidental explosion due to its leakage and may cause loss of valuable human life and property. The present paper is focused on the development of new sensing material in the form of composites to improve sensitivity, selectivity and stability. Present work shows the enhanced response of SnO2-ZnO composite structures for methane sensing and further increases its sensing response by loading appropriate catalyst on the sensor surface keeping in view of Fermi energy control mechanism and spillover mechanism. A stable sensor response of 77-85 % was obtained for SnO2-ZnO-Pd sensor structure over a wider range of temperature (160-260oC).
Thermo-chemical metastability of multilayer epitaxial graphene oxide: Experiments and density functional theory calculations
Authors: Zhou Si , Kim S. , Hu Y. , Berger C. , de Heer W. , Riedo Elisa , Bongiorno Angelo
Published: August 2012

Graphene oxide holds great promise for future applications in nano-technology. The chemistry of this material is not well understood. This understanding is crucial to enable future applications of graphene oxide. In this study, experiments and density functional theory calculations are combined to elucidate the chemical properties of multilayer graphene oxide obtained by oxidizing epitaxial graphene grown on silicon carbide via the Hummers method. This study shows that at room temperature as prepared graphene oxide films exhibit a uniform and homogeneous structure, include a minimal amount of edges and holes, and have an oxidation ratio of about 0.44. The comparison with density-functional calculations shows that graphene oxide includes a minimal amount of intercalated water molecules and well-defined fractions of epoxide and hydroxyl groups.
Implant-Guided Volumetric Analysis of Edentulous Maxillary Bone With Cone-Beam Computerized Tomography Scan. Maxillary Sinus Pneumatization Classification
Authors: Tolstunov Len , Thai David , Arellano Leo
Published: August 2012

The primary goal of this anatomic study was to measure the average bone volume of the edentulous maxilla with a cone-beam computerized tomography (CBCT) scan and to determine its suitability for implant treatment without additional bone grafting. The secondary goal of the study was to estimate the degree of sinus pneumatization (SP) in reviewed CBCT scans, assess the sinus-to-maxillary bone interrelationship in edentulism, and attempt to classify maxillary sinuses based on the degree of their pneumatization. This retrospective radiographic quantitative study consisted of the analysis of CBCT scans of 30 randomly selected maxillary edentulous patients who presented in 2008–2010 to the University of the Pacific, Arthur A. Dugoni School of Dentistry, for evaluation and treatment of their edentulism. A volume of edentulous maxillary bone mesial to the maxillary sinuses (intersinal region) that can be used for a full-arch implant treatment was evaluated based on specifically selected and clinically relevant measurement criteria. There were 30 CBCT scans of maxillary edentulous patients reviewed (9 men, 21 women) with a mean age of 67.3 years (range, 41 to 92 years). The total mean maxillary bone volume (MMBV) suitable for implantation was 4 408.1 mm3 and ranged from 1489.7 to 7263.1 mm3. The MMBV in the study was higher than an assumed or hypothetical bone volume minimally suitable for 4-implant treatment as proposed by the authors for comparative purposes (3500 mm3). The degree of SP as seen on a CBCT scan (60 sinuses analyzed on panoramic images of 30 CBCT scans) had the following results in the study: SP0 (clear: not interfering with implant treatment in cases of high/small sinus), 2 sinuses or 3.3%; SP1 (mild sinus enlargement), 29 sinuses or 48.3%; SP2 (moderate SP), 16 sinuses or 26.7%; SP3 (severe SP), 9 sinuses or 15.0%; and SP4 (extreme), 4 sinuses or 6.7%. Most analyzed maxillary sinuses (47 of 60, or 78.3%) were in the clear, mild, or moderate categories of SP (SP0, SP1, and SP2), which have a sufficient amount of maxillary bone beneath the maxillary sinuses to allow a full-arch implant treatment. An inverse correlation between SP and MMBV was observed. Although many other clinical criteria are important (bone quality, alveolar crest anatomy, etc), the results of this CBCT radiographic study indicate that in many maxillary edentulous cases, the existing bone quantity (volume) can be sufficient for a full-arch maxillary implant treatment with at least 4 implants without the additional trauma or expense of bone grafts and sinus lifts. A variety of implant treatment options can be proposed based on maxillary bone availability and bone-to-sinus interrelationship. It appears that with age and edentulism, the amount of available maxillary bone is steadily decreasing.
Brainstem auditory evoked response: application in neurology
Authors: Guerreiro Carlos A. M. , Ehrenberg Bruce L.
Published: August 2012

The tecnique that we use for eliciting brainstem auditory evoked responses (BAERs) is described. BAERs are a non-invasive and reliable clinical test when carefully performed. This test is indicated in the evaluation of disorders which may potentially involve the brainstem such as coma, multiple sclerosis posterior fossa tumors and others. Unsuspected lesions with normal radiologic studies (including CT-scan) can be revealed by the BAER.
Infiltración meningea por leucemia a celulas plasmáticas y por linfoma no Hodgkin: estudio citomorfologico en el liquido cefalo-raquideo
Authors: Tabares Olives Arnaldo
Published: August 2012

Son presentadas las características citomorfológicas anormales encontradas en el LCR de dos pacientes, uno de ellos sufriendo de leucemia aguda a células plasmáticas y otro de linfoma mixto no Hodgkin. Se enfatiza la importancia del estudio del LCR en estas patologias.
Disturbios cerebrais por vacuo-extração: estudo de 132 casos
Authors: Souza Denizard , Deitos Fatima
Published: August 2012

O presente estudo se propõe a uma correlação eletro-clínica em 132 pacientes cujos nascimentos foram auxiliados pela vácuo-extração. Estes pacientes apresentam convulsões, distúrbios de conduta, dificuldades de escolarização, distúrbios neurológicos nos quais os registros eletrencefalográficos acusam alterações inequívocas na proporção de cerca de 87% de casos.
Sindrome de Miller Fisher: relato de um caso
Authors: Scaff Milberto , Marchiori Paulo E. , Callegaro Dagoberto , Assis José Lamartine de
Published: August 2012

Os autores relatam caso de um paciente de 34 anos de idade, sexo masculino com oftalmoplegia externa, ataxia severa, distúrbio de marcha, apalestesia e discreta alteração da sensibilidade superficial nas palmas das mãos e plantas dos pés. A força muscular era normal. Este quadro se iniciou no 15º dia após contrair infecção de vias aéreas superiores de provável causa viral. O paciente foi tratado com ACTH melhorando rapidamente.
Hematoma sub-dural intracraniano pós-fístula liquórica raquidiana: registro de um caso
Authors: Antunes Apio Claudio Martins , Zauk Alfredo Degani
Published: August 2012

É relatado um caso de hematoma subdural intracraniano secundário a fistula liquórica raquidiana, tecendo os autores comentários sob sua rara incidência e fisiopatogenia.
Redes de empresas e seus efeitos sobre o turismo
Authors: Flecha Angela Cabral , Silva Alcides Volpato Castro e , Fusco José Paulo Alves , Bernardes Américo Tristão
Published: August 2012

O presente artigo tem como objetivo propor um modelo de alinhamento competitivo para a rede de atores do turismo, visando aumentar sua coesão e facilitar a busca de objetivos comuns. Tal proposta foi definida com base na expertise dos autores na análise de redes de turismo, aliada a resultados obtidos na pesquisa em Ouro Preto (MG). Dessa forma, foi possível perceber o peso dos atores envolvidos em função dos critérios de escolha utilizados pelos visitantes para configurar seu caminho dentro da região turística analisada e, assim, reforçar os relacionamentos existentes.
Competitividade das nações: análise da métrica utilizada pelo World Economic Forum
Authors: Carvalho Luciano Castro de , Di Serio Luiz Carlos , Vasconcellos Marcos Augusto de
Published: August 2012

A competitividade das nações é assunto relevante aos tomadores de decisão quando se trata da escolha do país que poderá render melhores resultados aos investimentos. Nessa linha, busca-se analisar a métrica de competitividade dos países utilizando conceitos da estatística multivariada, a fim de simplificar e evitar resultados dúbios quanto ao tema. Para isso, utilizaram-se as bases de dados de 2010 publicadas pelo World Economic Forum (WEF), que utiliza 12 pilares para estabelecer a condição competitiva de 133 países. Verificou-se que a métrica utilizada pelo WEF é redundante, já que utiliza pilares que representam o mesmo constructo. Verificou-se, ainda, que a prontidão tecnológica explica a competitividade do país em 86,5% e que a combinação entre estabilidade macroeconômica, qualidade do ensino superior e sofisticação dos negócios eleva esse percentual para 95,7%.
Hedonic analysis of cell phones sold with post-paid service plans in Brazil
Authors: Santi Rodrigo de , Lucinda Cláudio R.
Published: August 2012

The aim of this paper is to analyze the determining factors for the pricing of handsets sold with service plans, using the hedonic price method. This was undertaken by building a database comprising 48 handset models, under nine different service plans, over a period of 53 weeks in 2008, and resulted in 27 different attributes and a total number of nearly 300,000 data registers. The results suggest that the value of monthly subscriptions and calling minutes are important to explain the prices of handsets. Furthermore, both the physical volume and number of megapixels of a camera had an effect on the prices. The bigger the handset, the cheaper it becomes, and the more megapixels a camera phone has, the more expensive it becomes. Additionally, it was found that in 2008 Brazilian phone companies were subsidizing enabled data connection handsets.
As ONGs e a responsabilidade governamental com a escola básica no Brasil
Authors: Ghanem Elie
Published: August 2012

Este texto apresenta alguns dos principais significados que as ONGs assumiram no Brasil, os quais as posicionam diante do desafio do direito à educação. Desafio que abarca, especialmente, a escolarização pública e a definição do campo público e do privado. Nos dois aspectos deste desafio, são descritas as perspectivas seguidas pelas ONGs: a paliativa, a inovadora, a de mudança ou a de pressão política. Em conclusão, afirma que a atuação das ONGs tem vagado com diferentes sentidos, desarticuladamente, no que se refere às condições para realizar a educação como direito: o fortalecimento tanto do Estado quanto da sociedade civil, a interlocução entre estes polos e a influência recíproca entre educação e sistema político.
Gênero, sexualidade e políticas públicas de educação: um diálogo com a produção acadêmica
Authors: Vianna Cláudia
Published: August 2012

Este artigo traz resultados de levantamentos da produção acadêmica sobre a introdução do gênero e da sexualidade nas políticas públicas de educação no Brasil entre 1990 e 2009. O conjunto de obras examinadas concentra 73 títulos. Elas acompanham o desenvolvimento das políticas públicas de educação, as quais vêm enfatizando o currículo, e indicam atualmente a construção de uma agenda de políticas voltadas para a diversidade sexual, com a criação de muitos projetos e programas. A maioria dessa produção, muito recente e centrada no Sul e no Sudeste, é composta por dissertações, artigos de divulgação destas e ensaios, com um número reduzido de teses. Por meio da análise desse material identificaram-se dois movimentos analíticos: o uso do conceito de gênero, sob influência de Joan Scott, e, nas produções mais recentes, a crítica ao que Judith Butler denomina de "matriz heterossexual".
La expansión de universidades privadas en el caso argentino
Authors: Zelaya Marisa
Published: August 2012

Este trabajo aborda el tema de la privatización de la educación superior en el caso argentino. Se presentan, en primer lugar, los cambios producidos en el contexto latinoamericano y en nuestro país, en especial en el campo educativo, a partir de la instalación del paradigma neoliberal. A continuación, se describen dos momentos de expansión de universidades privadas en el caso argentino: uno es el período 1989- 1995, durante el cual crece el número de universidades privadas con sus especificidades; el segundo, abarca desde el año 1995 hasta la actualidad, y se caracteriza por la expansión del sector privado de la educación por medio de la creación de "ofertas distantes" o "Extensiones Áulicas". Por último, se aborda la dimensión espacial vinculada a la expansión de las extensiones.
A imagem da psicologia organizacional e do trabalho entre estudantes de psicologia: o impacto de uma experiência acadêmica
Authors: Bastos Antonio Virgílio Bittencourt , Morais José Henrique Miranda de , Santos Mariana Viana , Faria Ivan
Published: August 2012

Embora a Psicologia organizacional e do trabalho seja a segunda área de escolha de exercício profissional, os cursos de Psicologia, na sua maioria, ainda não a contemplam em toda a sua complexidade e dinâmica de transformação. Com isso, fortalecem-se esquemas cognitivos que representam esse campo de atuação profissional de forma limitada. O objetivo deste estudo foi o de caracterizar a imagem da Psicologia organizacional entre os estudantes de Psicologia e avaliar o impacto de uma experiência acadêmica sobre a mesma. A amostra consistiu de 150 alunos da única disciplina obrigatória do currículo relacionada à área, que responderam a um questionário aberto na primeira e na última semana do curso, no qual se pedia que escrevessem, espontaneamente, os conceitos e idéias que a área lhes evocava. Os resultados revelam alterações significativas na imagem, no início e no final do curso. Além de uma visão ampliada, os conteúdos evocados se tornaram mais positivos ao final do curso. Esses resultados apontam mudanças nos esquemas cognitivos dos estudantes, congruentes com as características e a filosofia que estruturavam a disciplina.
Psicólogo hospitalar da cidade de Recife - PE formação e atuação
Authors: Sá Adriana Karla Jeronimo Marques de , Lima Alexsandra Elenir Nunes , Santos Íris Maria da Silva Marques dos , Clemente Lídio
Published: August 2012

Identifica-se, como objeto deste estudo, a descrição do perfil do psicólogo hospitalar da cidade de Recife, enfatizando a sua formação e atuação, partindo da premissa que a formação acadêmica não oferece os subsídios necessários para a prática. Elaborou-se, para tanto, um questionário com questões fechadas, aplicado a 51 profissionais que trabalhavam em hospitais. Os resultados indicaram que a formação acadêmica não foi considerada suficiente para a atuação em hospital. Verificou-se, ainda, uma escassez de pesquisas e, em conseqüência, de publicações, o que deve refletir a própria formação, que não leva o aluno a articular profissão com pesquisa.
Educação para a morte
Authors: Kovács Maria Julia
Published: August 2012

A morte faz parte do desenvolvimento humano desde a mais tenra idade e acompanha o ser humano no seu ciclo vital, deixando suas marcas. Como preparar pessoas para esse fato tão presente na existência? Esse desafio é ainda mais urgente para os profissionais de saúde e educação. Perguntas têm assoberbado a humanidade, e respostas foram trazidas pelas religiões, ciências, artes, filosofias, entretanto, nenhuma delas é completa e universal. É sobre esses questionamentos e reflexões, sobre a busca de sentido à vida que a morte pode oferecer, sobre essa característica ou qualidade humana de questionamentos, de autoconhecimento, que pretendemos falar. A educação é entendida como desenvolvimento pessoal, aperfeiçoamento e cultivo do ser, que também pressupõe uma preparação para a morte, envolvendo comunicação, relacionamentos, perdas, situações-limite, como, por exemplo: fases do desenvolvimento, perda de pessoas significativas, doenças, acidentes, até o confronto com a própria morte. Serão discutidas várias propostas de educação para a morte tanto para o público leigo quanto para os profissionais.
Necessidades de saúde psicológica em crianças com deficiência mental
Authors: Araújo Maria das Graças , Vieira Maria Jésia
Published: August 2012

O encaminhamento de crianças com deficiência mental para o psicólogo provém, sobretudo, da preocupação com a adequação de suas condutas às expectativas sociais em detrimento de sua saúde mental e seu bem-estar. Neste trabalho, buscou-se identificar necessidades de saúde psicológica em crianças com deficiência mental, com indicação prévia de psicoterapia, para posterior análise do preparo do psicólogo para atender essas necessidades. A pesquisa foi realizada em escola especial pertencente à rede pública, na cidade de Aracaju. A amostra foi constituída por sete crianças, de sete a dez anos de idade, de ambos os sexos, com escolaridade correspondente à pré-alfabetização. Utilizou-se a observação participante para a coleta de dados, sistematizados por meio de análise de conteúdo. No grupo estudado, os resultados apontaram para a prevalência das necessidades de amor e pertencimento, seguida das necessidades de crescimento, dentro da hierarquia das necessidades humanas básicas descritas por Maslow.