bluuebunny/crossref_metadata_2025 huggingface dataset:
Ocean acidification slows retinal function in a damselfish through interference with GABAA receptors
Authors: Chung Wen-Sung , Marshall N. Justin , Watson Sue-Ann , Munday Philip L. , Nilsson Göran E.
Published: January 2014

Vision is one of the most efficient senses used by animals to catch prey and avoid predators. Therefore, any deficiency in the visual system could have important consequences for individual performance. We examined the effect of CO2 levels projected to occur by the end of this century on retinal responses in a damselfish, by determining the threshold of its flicker electroretinogram (fERG). The maximal flicker frequency of the retina was reduced by continuous exposure to elevated CO2, potentially impairing the capacity of fish to react to fast events. This effect was rapidly counteracted by treatment with a GABA antagonist (gabazine), indicating that GABAA receptor function is disrupted by elevated CO2. In addition to demonstrating the effects of elevated CO2 on fast flicker fusion of marine fishes, our results show that the fish retina could be a model system to study the effects of high CO2 on neural processing.
Pancreatico-pericardial fistula as a complication of chronic pancreatitis
Authors: Sommer Camille Anne , Wilcox C. Mel
Published: January 2014

Pancreatico-pericardial fistula is an extremely rare complication of chronic pancreatitis. We present a case of a 58-year-old man who presented with syncope. Transthoracic echocardiogram revealed a pericardial effusion with tamponade physiology. Pericardiocentesis and pericardial fluid analysis demonstrated a lipase level of 2321 U/L. Subsequently, an endoscopic retrograde cholangiopancreatography (ERCP) was performed, confirming the presence of a pancreatico-pericardial fistula (PPF) from the distal body of the pancreas. A pancreatic duct stent was placed across the duct disruption on two separate occasions; however, despite stent placement, the patient continued to re-accumulate pericardial fluid and deteriorated. While rare, PPFs may complicate chronic pancreatitis, may not respond to pancreatic duct stenting and may portend a poor prognosis.
Systems thinking for transformational change in health
Authors: Willis Cameron D , Best Allan , Riley Barbara , Herbert Carol P , Millar John , Howland David
Published: January 2014

Incremental approaches to introducing change in Canada’s health systems have not sufficiently improved the quality of services and outcomes. Further progress requires ‘large system transformation’, considered to be the systematic effort to generate coordinated change across organisations sharing a common vision and goal. This essay draws on ongoing dialogue relating to transformation, and examines transformative efforts in the Saskatchewan health system. We aim to build a shared understanding of systems thinking in the context of transformation, and to outline examples of how systems thinking perspectives, with an emphasis on the role of evidence, may inform strategy for complex change initiatives.
Procedures and claims among US evidence-producing organisations: the case of the Incredible Years programme
Authors: Karlsson Patrik , Bergmark Anders , Lundström Tommy
Published: January 2014

We explore how four evidence-producing organisations in the US go ahead when they rate the evidence base for psychosocial interventions, using the Incredible Years programme as our case study. The findings demonstrate variation in the procedures and resulting evidence claims across the organisations, with some organisations being strict and some being permissive. The presence of such conflicting practices highlights central challenges for the evidence-based practice framework and its ambition of obtaining uniform evidence statements. We conclude that practitioners and policy makers should be aware of such variation in order to be able to make informed decisions regarding which programmes to use.
Ideología política en torno a «issue»s y valores sociales: un estudio correlacional en ciudadanos de Córdoba/Argentina
Authors: Brussino Silvina , Imhoff Débora , Rabbia Hugo H. , Paz García Ana Pamela
Published: January 2014

El objetivo del presente estudio es analizar la relación existente entre los valores sociales y la ideología política de los ciudadanos cordobeses. Para ello, se tomó una muestra cuotificada por nivel socioeconómico, edad y sexo de 373 ciudadanos de Córdoba entre 18 a 65 años de edad. A los participantes seleccionados se les aplicó a) la escala de ideología política que considera posicionamientos situacionales sobre los siguientes tópicos específicos: política social, economía, sexualidad, drogas, religión, ecología, seguridad, comunicación (Brussino, Imhoff, Rabbia y Paz García); y b) el cuestionario de los valores básicos, propuesto por Gouveia et al. (2008), que está compuesto por 18 valores agrupados en seis orientaciones generales. Los datos obtenidos fueron sometidos a un análisis correlacional indicando que los distintos posicionamientos ideológicos analizados se relacionan diferencialmente con los valores sociales de los ciudadanos de Córdoba. En la misma línea, se efectuaron análisis de regresión múltiple a través del método de pasos sucesivos, mediante el cual se constató la contribución específica que realizan los valores sociales a la explicación de los distintos posicionamientos ideológicos.
Izquierda y derecha: formas de definirlas, el caso latinoamericano y sus implicaciones
Authors: González Ferrer Luis Eduardo , Queirolo Velasco Rosario
Published: January 2014

Izquierda y derecha (o liberales y conservadores) son conceptos usados ampliamente para estudiar partidos y otros objetos políticos, pero tienen al menos dos problemas. Primero, no es claro que sean útiles fuera de las democracias prósperas. Segundo, no se los define de una única manera: hay dos grandes familias de enfoques. Por un lado, una tradición histórico-analítica y, por otro, un enfoque basado en las teorías espaciales de la competencia entre partidos. Este artículo compara dos clasificaciones de los partidos políticos de América Latina en la escala izquierda-derecha basadas en esos enfoques y muestra que son muy diferentes. En segundo lugar, sugiere una explicación para esas diferencias basada en pautas sistemáticas observadas en los datos, explicación que conduce a varias hipótesis que pueden ser verificadas empíricamente. Finalmente, muestra que la evidencia y la literatura disponibles apoyan esas hipótesis, y por lo tanto la explicación en sí misma.
Cultural Competence and Cultural Compensatory Mechanisms in Binational Households
Authors: Cross Samantha N.N. , Gilly Mary C.
Published: January 2014

Although it is well-known that the U.S. population is increasingly culturally diverse, cultural diversity within U.S. households is less recognized. This study investigates the effects of cultural dynamics on decision roles and influence within the binational household. In particular, the authors study households in which one spouse is from the United States and the other is an immigrant. The analysis uses survey data and in-depth interviews. Cultural competence (i.e., knowledge of country of residence) as a source of expert power and as a form of cultural capital in family decision making emerge as overarching themes. The authors also find that one family member may engage in cultural compensatory mechanisms in consumption in response to the immigrant family member's sacrifices (i.e., moving to the United States). The authors close with a discussion of the implications for family decision-making theory, marketers, and society.
Authenticity is Contagious: Brand Essence and the Original Source of Production
Authors: Newman George E. , Dhar Ravi
Published: January 2014

It is well established that differences in manufacturing location can affect consumer preferences through lay inferences about production quality. In this article, the authors take a different approach to this topic by demonstrating how beliefs in contagion (the notion that objects may acquire a special aura or “essence” from their past) influence perceptions of authenticity for everyday consumer products and brands. Specifically, they find that due to a belief in contagion, products from a company's original manufacturing location are viewed as containing the essence of the brand. In turn, this belief in transferred essence leads consumers to view products from the original factory as more authentic and valuable than identical products made elsewhere. The authors further reveal that consumers who are higher in sensitivity to contagion are more likely to exhibit this effect and that activating the concept of contagion enhances preferences for products made in the brand's original factory. The authors close by discussing theoretical and practical implications of these findings.
Reviews without a Purchase: Low Ratings, Loyal Customers, and Deception
Authors: Anderson Eric T. , Simester Duncan I.
Published: January 2014

The authors document that approximately 5% of product reviews on a large private label retailer's website are submitted by customers with no record of ever purchasing the product they are reviewing. These reviews are significantly more negative than other reviews. They are also less likely to contain expressions describing the fit or feel of the items and more likely to contain linguistic cues associated with deception. More than 12,000 of the firm's best customers have written reviews without confirmed transactions. On average, these customers have each made more than 150 purchases from the firm. This makes it unlikely that the reviews were written by the employees or agents of a competitor and suggests that deceptive reviews may not be limited to the strategic actions of firms. Instead, the phenomenon may be far more prevalent, extending to individual customers who have no financial incentive to influence product ratings.
Static Klein–Gordon–Maxwell–Proca systems in 4-dimensional
closed manifolds. II
Authors: Druet Olivier , Hebey Emmanuel , Vétois Jérôme
Published: January 2014

We discuss static Klein–Gordon–Maxwell–Proca systems
in the critical case of 4-dimensional closed manifolds in the continuation of
Hebey–Truong [J. reine angew. Math. 667 (2012), 221–248]. We prove phase stability for all possible phases in the nonpositively curved case, and in the positively curved case when the phase lies in some set that we show to be
maximal in the case of the round sphere.
Effects of thermal modification on wood ultrastructure analyzed with crystallographic texture
Authors: Olek Wiesław , Bonarski Jan T.
Published: January 2014

The changes in ultrastructure of thermally modified beech and poplar wood have been studied by means of the crystallographic texture analysis. The experimental pole figures have been registered based on the X-ray diffraction (XRD). The 3D texture function, i.e., the orientation distribution function (ODF) was calculated with the use of the procedure implemented for materials with the monoclinic lattice symmetry. The inverse pole figures were recalculated from the obtained ODF. Areas with specific crystallographic organization in wood were identified and gradual changes in intensities of moderately oriented areas were observed. Simultaneously, additional reorganization of crystalline cellulose was observed as a result of heat treatment. The integrated skeleton lines confirmed the gradual decomposition of hemicelluloses as well as the temporary increase of cellulose self-organization.
The extended reductive acetyl-CoA pathway: ATPases in metal cluster maturation and reductive activation
Authors: Jeoung Jae-Hun , Goetzl Sebastian , Hennig Sandra Elisabeth , Fesseler Jochen , Wörmann Christina , Dendra Julia , Dobbek Holger
Published: January 2014

The reductive acetyl-coenzyme A (acetyl-CoA) pathway, also known as the Wood-Ljungdahl pathway, allows reduction and condensation of two molecules of carbon dioxide (CO2) to build the acetyl-group of acetyl-CoA. Productive utilization of CO2 relies on a set of oxygen sensitive metalloenzymes exploiting the metal organic chemistry of nickel and cobalt to synthesize acetyl-CoA from activated one-carbon compounds. In addition to the central catalysts, CO dehydrogenase and acetyl-CoA synthase, ATPases are needed in the pathway. This allows the coupling of ATP binding and hydrolysis to electron transfer against a redox potential gradient and metal incorporation to (re)activate one of the central players of the pathway. This review gives an overview about our current knowledge on how these ATPases achieve their tasks of maturation and reductive activation.
Histological evaluation of socket preservation with different bone grafting materials
Authors: Salamanca Eisner , Lin Hsi-Kuei , Feng Sheng-Wei , Huang Haw-Ming , Teng Nai-Chia , Chang Wei-Jen
Published: January 2014

The aim of this study was to compare different bone grafting materials and their contribution to socket preservation. In six beagle dogs, bilateral mandibular second, third, and fourth premolars were hemisectioned and extracted. The following four treatment modalities were randomly allocated: (1) empty control site, (2) collagen plug, (3) Bio Oss-collagen, (4) HA/β-TCP-collagen. After 2 and 4 weeks, the animals were sacrificed, and decalcified sections were obtained for histological analysis. New bone formation was homogeneous, progressive, and centripetal in all materials. Remodeling as well as the calcification of the newly formed bone was observed. In addition, well-connected trabeculae surrounding the degraded materials were observed. Nearly mature bone, which demonstrated less cellular, more mineralized, and structurally more organized into lamellar bone was noted in HA/β-TCP-collagen composite. In this study, Bio Oss-collagen and HA/β-TCP-collagen produced a newly biomimetic composite biomaterial and could prove to be a superior bone substitute material, both structurally and functionally, which could be used in the repair of bone defects collagen composite.
Effects of Psyching-Up on Sprint Performance
Authors: Hammoudi-Nassib Sarra , Nassib Sabri , Chtara Moktar , Briki Walid , Chaouachi Anis , Tod David , Chamari Karim
Published: January 2014

Hammoudi-Nassib, S, Nassib, S, Chtara, M, Briki, W, Chaouachi, A, Tod, D, and Chamari, K. Effects of psyching-up on sprint performance. J Strength Cond Res 31(8): 2066–2074, 2017—The present research aimed at examining whether the psyching up (PU) strategies improve performance in 30-m sprinting. Sixteen male sprinters (age, 20.6 ± 1.3 years; body mass, 77.5 ± 7.1 kg; height, 180.8 ± 5.6 cm) participated in this study. Before each experimental session, the Hooper index was used to monitor the subject’s feeling for the quality of sleep of the previous night, perceived quantity of stress, delayed onset muscle soreness, and fatigue. After completing general and specific warm-up, participants had to rate their degree of self-confidence. Then, they were asked to follow 1 of these 4 conditions: Imagery (experimental PU condition), Preparatory arousal (experimental PU condition), Attention placebo (control condition), and Distraction (control condition) during the final 30 seconds of the rest period right before performing a 30-m sprint. Participants separately and randomly performed all conditions. Results showed that although the imagery and preparatory arousal strategies contributed to increase the performance in the short-distance sprints (from 0 to 10 m), the imagery strategy contributed to increase the performance in the 30-m sprints. These findings support the general view that the PU strategies could improve athletic performance.
Structural Maturation and Brain Activity Predict Future Working Memory Capacity during Childhood Development
Authors: Ullman Henrik , Almeida Rita , Klingberg Torkel
Published: January 2014

Human working memory capacity develops during childhood and is a strong predictor of future academic performance, in particular, achievements in mathematics and reading. Predicting working memory development is important for the early identification of children at risk for poor cognitive and academic development. Here we show that structural and functional magnetic resonance imaging data explain variance in children's working memory capacity 2 years later, which was unique variance in addition to that predicted using cognitive tests. While current working memory capacity correlated with frontoparietal cortical activity, the future capacity could be inferred from structure and activity in basal ganglia and thalamus. This gives a novel insight into the neural mechanisms of childhood development and supports the idea that neuroimaging can have a unique role in predicting children's cognitive development.
A Spiking Neural Integrator Model of the Adaptive Control of Action by the Medial Prefrontal Cortex
Authors: Bekolay Trevor , Laubach Mark , Eliasmith Chris
Published: January 2014

Subjects performing simple reaction-time tasks can improve reaction times by learning the expected timing of action-imperative stimuli and preparing movements in advance. Success or failure on the previous trial is often an important factor for determining whether a subject will attempt to time the stimulus or wait for it to occur before initiating action. The medial prefrontal cortex (mPFC) has been implicated in enabling the top-down control of action depending on the outcome of the previous trial. Analysis of spike activity from the rat mPFC suggests that neural integration is a key mechanism for adaptive control in precisely timed tasks. We show through simulation that a spiking neural network consisting of coupled neural integrators captures the neural dynamics of the experimentally recorded mPFC. Errors lead to deviations in the normal dynamics of the system, a process that could enable learning from past mistakes. We expand on this coupled integrator network to construct a spiking neural network that performs a reaction-time task by following either a cue-response or timing strategy, and show that it performs the task with similar reaction times as experimental subjects while maintaining the same spiking dynamics as the experimentally recorded mPFC.
The Hormone Prolactin Is a Novel, Endogenous Trophic Factor Able to Regulate Reactive Glia and to Limit Retinal Degeneration
Authors: Arnold Edith , Thebault Stéphanie , Baeza-Cruz German , Arredondo Zamarripa David , Adán Norma , Quintanar-Stéphano Andrés , Condés-Lara Miguel , Rojas-Piloni Gerardo , Binart Nadine , Martínez de la Escalera Gonzalo , Clapp Carmen
Published: January 2014

Retinal degeneration is characterized by the progressive destruction of retinal cells, causing the deterioration and eventual loss of vision. We explored whether the hormone prolactin provides trophic support to retinal cells, thus protecting the retina from degenerative pressure. Inducing hyperprolactinemia limited photoreceptor apoptosis, gliosis, and changes in neurotrophin expression, and it preserved the photoresponse in the phototoxicity model of retinal degeneration, in which continuous exposure of rats to bright light leads to retinal cell death and retinal dysfunction. In this model, the expression levels of prolactin receptors in the retina were upregulated. Moreover, retinas from prolactin receptor-deficient mice exhibited photoresponsive dysfunction and gliosis that correlated with decreased levels of retinal bFGF, GDNF, and BDNF. Collectively, these data unveiled prolactin as a retinal trophic factor that may regulate glial–neuronal cell interactions and is a potential therapeutic molecule against retinal degeneration.
Differential Associative Training Enhances Olfactory Acuity inDrosophila melanogaster
Authors: Barth Jonas , Dipt Shubham , Pech Ulrike , Hermann Moritz , Riemensperger Thomas , Fiala André
Published: January 2014

Training can improve the ability to discriminate between similar, confusable stimuli, including odors. One possibility of enhancing behaviorally expressed discrimination (i.e., sensory acuity) relies on differential associative learning, during which animals are forced to detect the differences between similar stimuli.Drosophilarepresents a key model organism for analyzing neuronal mechanisms underlying both odor processing and olfactory learning. However, the ability of flies to enhance fine discrimination between similar odors through differential associative learning has not been analyzed in detail. We performed associative conditioning experiments using chemically similar odorants that we show to evoke overlapping neuronal activity in the fly's antennal lobes and highly correlated activity in mushroom body lobes. We compared the animals' performance in discriminating between these odors after subjecting them to one of two types of training: either absolute conditioning, in which only one odor is reinforced, or differential conditioning, in which one odor is reinforced and a second odor is explicitly not reinforced. First, we show that differential conditioning decreases behavioral generalization of similar odorants in a choice situation. Second, we demonstrate that this learned enhancement in olfactory acuity relies on both conditioned excitation and conditioned inhibition. Third, inhibitory local interneurons in the antennal lobes are shown to be required for behavioral fine discrimination between the two similar odors. Fourth, differential, but not absolute, training causes decorrelation of odor representations in the mushroom body. In conclusion, differential training with similar odors ultimately induces a behaviorally expressed contrast enhancement between the two similar stimuli that facilitates fine discrimination.
Rapid Online Selection between Multiple Motor Plans
Authors: Nashed Joseph Y. , Crevecoeur Frédéric , Scott Stephen H.
Published: January 2014

Recent theories of voluntary control predict that multiple motor strategies can be precomputed and expressed throughout movement. We examined online decisional processing in humans by asking them to make reaching movements with obstacles located just to the sides of a direct path between start and end targets. On random trials, the limb was perturbed with one of four mechanical loads that varied in direction and amplitude. Notably, we observed two different strategies when we applied a perturbation (left medium-sized) that deviated the participants' hand directly toward an obstacle. In some trials, subjects directed their hand between the obstacles and in other trials to the left of the obstacles. Importantly, changes in the muscle stretch response between these two strategies were observed in <60 ms after perturbation, during the R2 long-latency epoch (∼45–75 ms). As predicted, the selected strategy depended on the estimated position of the limb when it was perturbed. In our second experiment, we presented either one or three potential goal targets. Movements initially directed to the closest target could be quickly redirected to other potential targets after a perturbation. Differences in muscle stretch responses for redirected movements were observed ∼75 ms after perturbation during the R3 long-latency epoch (∼75–105 ms). The results show that decisional processes are rapidly implemented during movement execution. In addition, our data suggest a hierarchical process with corrective responses on “how” to attain a behavioral goal expressed during the R2 epoch and responses on “what” goal to attain during the R3 epoch.
Nogo Receptor Homolog NgR2 Expressed in Sensory DRG Neurons Controls Epidermal Innervation by Interaction with Versican
Authors: Bäumer Bastian E. , Kurz Antje , Borrie Sarah C. , Sickinger Stephan , Dours-Zimmermann María T. , Zimmermann Dieter R. , Bandtlow Christine E.
Published: January 2014

Primary sensory afferents of the dorsal root ganglion (DRG) that innervate the skin detect a wide range of stimuli, such as touch, temperature, pain, and itch. Different functional classes of nociceptors project their axons to distinct target zones within the developing skin, but the molecular mechanisms that regulate target innervation are less clear. Here we report that the Nogo66 receptor homolog NgR2 is essential for proper cutaneous innervation. NgR2−/−mice display increased density of nonpeptidergic nociceptors in the footpad and exhibit enhanced sensitivity to mechanical force and innocuous cold temperatures. These sensory deficits are not associated with any abnormality in morphology or density of DRG neurons. However, deletion of NgR2 renders nociceptive nonpeptidergic sensory neurons insensitive to the outgrowth repulsive activity of skin-derived Versican. Biochemical evidence shows that NgR2 specifically interacts with the G3 domain of Versican. The data suggest that Versican/NgR2 signaling at the dermo-epidermal junction actsin vivoas a local suppressor of axonal plasticity to control proper density of epidermal sensory fiber innervation. Our findings not only reveal the existence of a novel and unsuspected mechanism regulating epidermal target innervation, but also provide the first evidence for a physiological role of NgR2 in the peripheral nervous system.
Motor Costs and the Coordination of the Two Arms
Authors: Salimpour Yousef , Shadmehr Reza
Published: January 2014

We have two arms, many muscles in each arm, and numerous neurons that contribute to their control. How does the brain assign responsibility to each of these potential actors? We considered a bimanual task in which people chose how much force to produce with each arm so that the sum would equal a target. We found that the dominant arm made a greater contribution, but only for specific directions. This was not because the dominant arm was stronger. Rather, it was less noisy. A cost that included unimanual noise and strength accounted for both direction- and handedness-dependent choices that young people made. To test whether there was a causal relationship between unimanual noise and bimanual control, we considered elderly people, whose unimanual noise is comparable in the two arms. We found that, in bimanual control, the elderly showed no preference for their dominant arm. We noninvasively stimulated the motor cortex to produce a change in unimanual strength and noise, and found a corresponding change in bimanual control. Using the noise measurements, we built a neuronal model. The model explained the anisotropic distribution of preferred directions of neurons in the monkey motor cortex and predicted that, in humans, there are changes in the number of these cortical neurons with handedness and aging. Therefore, we found that coordination can be explained by the noise and strength of each effector, where noise may be a reflection of the number of task-related neurons available for control of that effector in the motor cortex.
Pathogenic Mutation of Spastin Has Gain-of-Function Effects on Microtubule Dynamics
Authors: Solowska Joanna M. , D'Rozario Mitchell , Jean Daphney C. , Davidson Michael W. , Marenda Daniel R. , Baas Peter W.
Published: January 2014

Mutations to theSPG4gene encoding the microtubule-severing protein spastin are the most common cause of hereditary spastic paraplegia. Haploinsufficiency, the prevalent model for the disease, cannot readily explain many of its key aspects, such as its adult onset or its specificity for the corticospinal tracts. Treatment strategies based solely on haploinsufficiency are therefore likely to fail. Toward developing effective therapies, here we investigated potential gain-of-function effects of mutant spastins. The full-length human spastin isoform called M1 or a slightly shorter isoform called M87, both carrying the same pathogenic mutation C448Y, were expressed in three model systems: primary rat cortical neurons, fibroblasts, and transgenicDrosophila. Although both isoforms had ill effects on motor function in transgenic flies and decreased neurite outgrowth from primary cortical neurons, mutant M1 was notably more toxic than mutant M87. The observed phenotypes did not result from dominant-negative effects of mutated spastins. Studies in cultured cells revealed that microtubules can be heavily decorated by mutant M1 but not mutant M87. Microtubule-bound mutant M1 decreased microtubule dynamics, whereas unbound M1 or M87 mutant spastins increased microtubule dynamics. The alterations in microtubule dynamics observed in the presence of mutated spastins are not consistent with haploinsufficiency and are better explained by a gain-of-function mechanism. Our results fortify a model wherein toxicity of mutant spastin proteins, especially mutant M1, contributes to axonal degeneration in the corticospinal tracts. Furthermore, our results provide details on the mechanism of the toxicity that may chart a course toward more effective treatment regimens.
Dscam1 Is Required for Normal Dendrite Growth and Branching But Not for Dendritic Spacing inDrosophilaMotoneurons
Authors: Hutchinson Katie M. , Vonhoff Fernando , Duch Carsten
Published: January 2014

Down syndrome cell adhesion molecule, Dscam, serves diverse neurodevelopmental functions, including axon guidance and synaptic adhesion, as well as self-recognition and self-avoidance, depending on the neuron type, brain region, or species under investigation. InDrosophila, the extensive molecular diversity that results from alternative splicing of Dscam1 into >38,000 isoforms provides neurons with a unique molecular code for self-recognition in the nervous system. Each neuron produces only a small subset of Dscam1 isoforms, and distinct Dscam1 isoforms mediate homophilic interactions, which in turn, result in repulsion and even spacing of self-processes, while allowing contact with neighboring cells. While these mechanisms have been shown to underlie mushroom body development and spacing of mechanosensory neuron dendrites, here we report that Dscam1 plays no role in adultDrosophilamotoneuron dendrite spacing, but is required for motoneuron dendritic growth. Targeted expression of Dscam-RNAi in an identified flight motoneuron did not impact dendrite spacing, but instead produced overgrowth. Increasing the knockdown strength severely reduced dendritic growth and branching. Similarly, Dscam mutant motoneurons in an otherwise control background (MARCM) were completely devoid of mature dendrites. These data suggest that Dscam1 is required cell autonomously for normal adult motoneuron dendrite growth inDrosophila. This demonstrates a previously unreported role ofDrosophilaDscam1 in central neuron development, and expands the current understanding that Dscam1 operates as a cell adhesion molecule that mediates homophilic repulsion.
EMG Activation Patterns Associated with High Frequency, Long-Duration Intracortical Microstimulation of Primary Motor Cortex
Authors: Griffin Darcy M. , Hudson Heather M. , Belhaj-Saïf Abderraouf , Cheney Paul D.
Published: January 2014

The delivery of high-frequency, long-duration intracortical microstimulation (HFLD-ICMS) to primary motor cortex (M1) in primates produces hand movements to a common final end-point regardless of the starting hand position (Graziano et al., 2002). We have confirmed this general conclusion. We further investigated the extent to which the (1) temporal pattern, (2) magnitude, and (3) latency of electromyographic (EMG) activation associated with HFLD-ICMS-evoked movements are dependent on task conditions, including limb posture. HFLD-ICMS was applied to layer V sites in M1 cortex. EMG activation with HFLD-ICMS was evaluated while two male rhesus macaques performed a number of tasks in which the starting position of the hand could be varied throughout the workspace. HFLD-ICMS-evoked EMG activity was largely stable across all parameters tested independent of starting hand position. The most common temporal pattern of HFLD-ICMS-evoked EMG activity (58% of responses) was a sharp rise to a plateau. The plateau level was maintained essentially constant for the entire duration of the stimulus train. The plateau pattern is qualitatively different from the largely bell-shaped patterns typical of EMG activity associated with natural goal directed movements (Brown and Cooke, 1990; Hoffman and Strick, 1999). HFLD-ICMS produces relatively fixed parameters of muscle activation independent of limb position. We conclude that joint movement associated with HFLD-ICMS occurs as a function of the length–tension properties of stimulus-activated muscles until an equilibrium between agonist and antagonist muscle force is achieved.
Tissue Plasminogen Activator Contributes to Alterations of Neuronal Migration and Activity-Dependent Responses in Fragile X Mice
Authors: Achuta V. Swaroop , Rezov Veronika , Uutela Marko , Louhivuori Verna , Louhivuori Lauri , Castrén Maija L.
Published: January 2014

Fragile X syndrome (FXS) is the most common inherited neurodevelopmental disorder with intellectual disability. Here, we show that the expression of tissue plasminogen activator (tPA) is increased in glial cells differentiated from neural progenitors ofFmr1knock-out mice, a mouse model for FXS, and that tPA is involved in the altered migration and differentiation of these progenitors lacking FMR1 protein (FMRP). When tPA function is blocked with an antibody, enhanced migration of doublecortin-immunoreactive neurons in 1 d differentiated FMRP-deficient neurospheres is normalized. In time-lapse imaging, blocking the tPA function promotes early glial differentiation and reduces the velocity of nuclear movement of FMRP-deficient radial glia. In addition, we show that enhanced intracellular Ca2+responses to depolarization with potassium are prevented by the treatment with the tPA-neutralizing antibody in FMRP-deficient cells during early neural progenitor differentiation. Alterations of the tPA expression in the embryonic, postnatal, and adult brain ofFmr1knock-out mice suggest an important role for tPA in the abnormal neuronal differentiation and plasticity in FXS. Altogether, the results indicate that tPA may prove to be an interesting potential target for pharmacological intervention in FXS.
Dissociable Memory Traces within the Macaque Medial Temporal Lobe Predict Subsequent Recognition Performance
Authors: Miyamoto Kentaro , Adachi Yusuke , Osada Takahiro , Watanabe Takamitsu , Kimura Hiroko M. , Setsuie Rieko , Miyashita Yasushi
Published: January 2014

Functional magnetic resonance imaging (fMRI) studies have revealed that activity in the medial temporal lobe (MTL) predicts subsequent memory performance in humans. Because of limited knowledge on cytoarchitecture and axonal projections of the human MTL, precise localization and characterization of the areas that can predict subsequent memory performance are benefited by the use of nonhuman primates in which integrated approach of the MRI- and cytoarchiture-based boundary delineation is available. However, neural correlates of this subsequent memory effect have not yet been identified in monkeys. Here, we used fMRI to examine activity in the MTL during memory encoding of events that monkeys later remembered or forgot. Application of both multivoxel pattern analysis and conventional univariate analysis to high-resolution fMRI data allowed us to identify memory traces within the caudal entorhinal cortex (cERC) and perirhinal cortex (PRC), as well as within the hippocampus proper. Furthermore, activity in the cERC and the hippocampus, which are directly connected, was responsible for encoding the initial items of sequentially presented pictures, which may reflect recollection-like recognition, whereas activity in the PRC was not. These results suggest that two qualitatively distinct encoding processes work in the monkey MTL and that recollection-based memory is formed by the interplay of the hippocampus with the cERC, a focal cortical area anatomically closer to the hippocampus and hierarchically higher than previously believed. These findings will advance the understanding of common memory system between humans and monkeys and accelerate fine electrophysiological characterization of these dissociable memory traces in the monkey MTL.
Responses to Cell Loss Become Restricted as the Supporting Cells in Mammalian Vestibular Organs Grow Thick Junctional Actin Bands That Develop High Stability
Authors: Burns Joseph C. , Corwin Jeffrey T.
Published: January 2014

Sensory hair cell (HC) loss is a major cause of permanent hearing and balance impairments for humans and other mammals. Yet, fish, amphibians, reptiles, and birds readily replace HCs and recover from such sensory deficits. It is unknown what prevents replacement in mammals, but cell replacement capacity declines contemporaneously with massive postnatal thickening of F-actin bands at the junctions between vestibular supporting cells (SCs). In non-mammals, SCs can give rise to regenerated HCs, and the bands remain thin even in adults. Here we investigated the stability of the F-actin bands between SCs in ears from chickens and mice and Madin-Darby canine kidney cells. Pharmacological experiments and fluorescence recovery after photobleaching (FRAP) of SC junctions in utricles from mice that express a γ-actin–GFP fusion protein showed that the thickening F-actin bands develop increased resistance to depolymerization and exceptional stability that parallels a sharp decline in the cell replacement capacity of the maturing mammalian ear. The FRAP recovery rate and the mobile fraction of γ-actin–GFP both decreased as the bands thickened with age and became highly stabilized. In utricles from neonatal mice, time-lapse recordings in the vicinity of dying HCs showed that numerous SCs change shape and organize multicellular actin purse strings that reseal the epithelium. In contrast, adult SCs appeared resistant to deformation, with resealing responses limited to just a few neighboring SCs that did not form purse strings. The exceptional stability of the uniquely thick F-actin bands at the junctions of mature SCs may play an important role in restricting dynamic repair responses in mammalian vestibular epithelia.
Binocular Rivalry: Frontal Activity Relates to Introspection and Action But Not to Perception
Authors: Frässle Stefan , Sommer Jens , Jansen Andreas , Naber Marnix , Einhäuser Wolfgang
Published: January 2014

When two dissimilar stimuli are presented to the eyes, perception alternates between multiple interpretations, a phenomenon dubbed binocular rivalry. Numerous recent imaging studies have attempted to unveil neural substrates underlying multistable perception. However, these studies had a conceptual constraint: access to observers' perceptual state relied on their introspection and active report. Here, we investigated to what extent neural correlates of binocular rivalry in healthy humans are confounded by this subjective measure and by action. We used the optokinetic nystagmus and pupil size to objectively and continuously map perceptual alternations for binocular-rivalry stimuli. Combining these two measures with fMRI allowed us to assess the neural correlates of binocular rivalry time locked to the perceptual alternations in the absence of active report. When observers were asked to actively report their percept, our objective measures matched the report. In this active condition, objective measures and subjective reporting revealed that occipital, parietal, and frontal areas underlie the processing of binocular rivalry, replicating earlier findings. Furthermore, objective measures provided additional statistical power due to their continuous nature. Importantly, when observers passively experienced rivalry without reporting perceptual alternations, a different picture emerged: differential neural activity in frontal areas was absent, whereas activation in occipital and parietal regions persisted. Our results question the popular view of a driving role of frontal areas in the initiation of perceptual alternations during binocular rivalry. Instead, we conclude that frontal areas are associated with active report and introspection rather than with rivalry per se.
Activity-Dependent Modulation of Layer 1 Inhibitory Neocortical Circuits by Acetylcholine
Authors: Brombas Arne , Fletcher Lee N. , Williams Stephen R.
Published: January 2014

Layer 1 neocortical GABAergic interneurons control the excitability of pyramidal neurons through cell-class-specific direct inhibitory and disynaptic disinhibitory circuitry. The engagement of layer 1 inhibitory circuits during behavior is powerfully controlled by the cholinergic neuromodulatory system. Here we report that acetylcholine (ACh) influences the excitability of layer 1 interneurons in a cell-class and activity-dependent manner. Whole-cell recordings from identified layer 1 interneurons of the rat somatosensory neocortex revealed that brief perisomatic application of ACh excited both neurogliaform cells (NGFCs) and classical-accommodating cells (c-ACs) at rest by the activation of nicotinic receptors. In contrast, under active, action potential firing states, ACh excited c-ACs, but inhibited NGFCs through muscarinic receptor-mediated, IP3receptor-dependent elevations of intracellular calcium that gated surface-membrane calcium-activated potassium channels. These excitatory and inhibitory actions of ACh could be switched between by brief periods of NGFC action potential firing. Paired recordings demonstrated that cholinergic inhibition of NGFCs disinhibited the apical dendrites of layer 2/3 pyramidal neurons by silencing widespread, GABABreceptor-mediated, monosynaptic inhibition. Together, these data suggest that the cholinergic system modulates layer 1 inhibitory circuits in an activity-dependent manner to dynamically control dendritic synaptic inhibition of pyramidal neurons.
Analysis of Local and Global Topographic Order in Mouse Retinocollicular Maps
Authors: Willshaw David J. , Sterratt David C. , Teriakidis Adrianna
Published: January 2014

We introduce the Lattice Method for the quantitative assessment of the topographic order within the pattern of connections between two structures. We apply this method to published visuocollicular mapping data obtained by Fourier-based intrinsic imaging of mouse colliculus. We find that, in maps from wild types and β2 knock-outs, at least 150 points on the colliculus are represented in the visual field in the correct relative order. In maps from animals with knock-out of the three ephrinA ligands (TKO), thought to specify the rostrocaudal axis of the map, the projection on the colliculus of each small circular area of visual field is elongated approximately rostrocaudally. Of these projections, 9% are made up of two distinct regions lying along the direction of ingrowth of retinal fibers. These are similar to the ectopic projections found in other ephrinA knock-out data. Coexisting with the ectopic projections, each TKO map contains a submap where neighbor–neighbor relations are preserved, which is ordered along both rostrocaudal and mediolateral axes, in the orientation found in wild-type maps. The submaps vary in size with order well above chance level, which can approach the order in wild-type maps. Knock-out of both β2 and two of the three ephrinAs yields maps with some order. The ordered TKO maps cannot be produced by correlated neural activity acting alone, as this mechanism is unable to specify map orientation. These results invite reassessment of the role of molecular signaling, particularly that of ephrinAs, in the formation of ordered nerve connections.
Before Restriction Became Exclusion
Authors: Lew-Williams Beth
Published: January 2014

The Chinese Exclusion Act (1882) marked a turning point in the history of U.S. immigration control, but it was not as definitive a move toward gatekeeping as historians have suggested. Contemporaries called the 1882 law the “Chinese Restriction Act,” reserving the term “exclusion” for its successor in 1888. The rhetorical change paralleled an important shift in policy. During Chinese Restriction (1882–1888), the United States so valued its relationship with China that it made immigration restriction subject to diplomatic negotiation. Only after the Restriction Act failed and China signaled capitulation did the United States enact Chinese Exclusion (1888), which prohibited Chinese workers, asserted America’s sovereign power to exclude, and developed modern systems of enforcement. The transition from diplomatic Restriction to unilateral Exclusion represents a powerful aggrandizement of American power.
The Chinle Dog Shoots
Authors: Johnson Khalil Anthony
Published: January 2014

In the 1950s, the Bureau of Indian Affairs (BIA) managed the Navajo Reservation's feral dog population by scheduling semi-annual “dog shoots.” After one gruesome dog shoot resulted in seventeen slaughtered dogs in Chinle, Arizona, community members pressed local BIA authorities to reform reservation dog control, an effort that pitted the interethnic community against an authoritarian form of settler-colonial governance. Because citizenship on the reservation—for Navajo and non-Navajo alike—was effectively rendered inferior to that of citizens outside the reservation, substantive changes to local BIA policies required an alliance with a constituency beyond the reservation’s borders, one with full access to state power—in this case, the National Dog Welfare Guild. This article thus demonstrates Native American grass-roots activism and boundary politics against oppressive federal authority.
Reaching Acceptance
Authors: Ohs Jennifer E.
Published: January 2014

Health-care decisions at the latter end of the lifespan are meaningful communicative experiences that can have important consequences for the health and well being of older adults. Using problematic integration theory as a guiding framework, I examined patterns of communication involved with the personal health-care decisions of older adults. I conducted interviews with sixty-two older adults in the process of considering a major health-care decision. Thematic analysis revealed that as older adults attempted to integrate and make sense of incongruent information related to their health-care decisions, interactions with physicians, adult children, spouses, and friends were influential. Additionally, overcoming avoidance, managing uncertainty, and reaching acceptance emerged in the health-care decision experiences of older adults in ways meaningful for problematic integration.
Telomerase activity is more significant for predicting the outcome of IVF treatment than telomere length in granulosa cells
Authors: Wang Wenjun , Chen Hong , Li Ruiqi , Ouyang Nengyong , Chen Jinghua , Huang Lili , Mai Meiqi , Zhang Ningfeng , Zhang Qingxue , Yang Dongzi
Published: January 2014

Our previous study has demonstrated that luteinized granulosa cells (GCs) have the potential to proliferate and that the telomerase activity (TA) of luteinized GCs may predict the clinical outcomes of IVF treatment. However, in the field of telomere research, there have always been different opinions regarding the significance of TA and telomere length (TL). Thus, in the present study, we compared the effects of these two parameters on IVF treatment outcomes in the same individuals. TL did not differ significantly between the pregnant group and the non-pregnant group. The TA, number of retrieved oocytes and rate of blastocyst transfer were significantly higher in the pregnant group than in the non-pregnant group (0.8825 OD×mm, 12.75±2.20 and 34.48%, respectively, in the pregnant group vs 0.513 OD×mm, 11.60±0.93 and 14.89%, respectively, in the non-pregnant group (P<0.05)), while basal FSH level was lower in the pregnant group than in the non-pregnant group. The subjects did not differ with regard to ovarian stimulation or other clinical characteristics. A TA increase of 1 OD×mm increased the chance of becoming pregnant 4.769-fold (odds ratio: 5.769, 95% CI: 1.434–23.212,P<0.014). The areas under the receiver operating characteristic curves were 0.576 for TL and 0.674 for TA (P=0.271 andP<0. 012 respectively). The corresponding cut-off points were 4.470 for TL and 0.650 OD×mm for TA. These results demonstrate that TA is a better predictor of pregnancy outcomes following IVF treatment than TL. No other clinical parameters, including age, baseline FSH level or peak oestradiol level, distinguished between the pregnant group and the non-pregnant group as effectively as TA.