bluuebunny/crossref_metadata_2025 huggingface dataset:
Fragility Analysis of Reinforced Masonry Shear Walls
Authors: Murcia-Delso Juan , Shing P. Benson
Published: November 2012

Fragility functions have been developed to evaluate the damageability of fully grouted and partially grouted reinforced masonry shear walls subjected to in-plane seismic loading. Six damage states are considered, representing different levels of flexure, diagonal shear, and sliding shear damage. For each damage state, two classes of fragility functions have been developed. One has the story-drift ratio as the demand parameter. The other uses normalized demand parameters that account for the specific loading condition and design details of a wall component. All the fragility functions are derived from experimental data except for those developed for partially grouted walls and the sliding shear damage state. With both classes of fragility functions, the seismic damageability of flexure-dominated cantilever reinforced masonry shear walls in a four-story building has been assessed. It has been shown that the normalized flexural demand parameter provides a better correlation to the degree of damage developed in a wall than the story-drift ratio.
Ceiling Anchorage Loads during Shake Table Tests of a Full-Scale Five-Story Building
Authors: Hoehler Matthew S. , Motoyui Shojiro , Kasai Kazuhiko , Sato Yasuaki , Hikino Tsuyoshi , Hirase Kosuke
Published: November 2012

This paper documents tests conducted to assess anchor loading characteristics and distributions over a suspended ceiling before, during, and after a series of simulated earthquakes. Miniature force-measurement devices were installed on a 4.5 by 6.5 m section of gypsum board ceiling located in a full-scale five-story building. The building was subjected to a series of four scaled earthquakes until failure of the ceiling occurred. The test results show that the ceiling-to-slab acceleration amplification was a factor of about 6.4 for horizontal accelerations and 15.0 for vertical acceleration immediately prior to failure of the ceiling. Variation of the peak axial anchor forces across the ceiling under earthquake loading was significant; the maxima exceed the mean value by a factor of up to 3.8 times. Rainflow counting of axial anchor load cycles is used to provide cycling demand for both the linear and nonlinear response of the ceiling.
Effect of Ground Motion Modification Technique on Seismic Geotechnical Engineering Analyses
Authors: Zekkos Dimitrios , Carlson Clinton , Nisar Ahmed , Ebert Stephanie
Published: November 2012

Ground motion modification (or spectral matching) has been criticized, but has many appealing characteristics and is widely used in practice. Modification of ground motions can be performed in either the time domain or the frequency domain. Depending on the choice of modification technique, modified ground motions can be significantly different from each other as well as from the original ground motion. This paper studies the impact of these differences on seismic geotechnical analyses for two different site profiles using two earthquake scenarios and a total of 20 ground motions. This study shows that the final results are influenced by many factors such as the original (seed) ground motion, the target spectrum, and the local site conditions, in addition to the ground motion modification technique used. The results also show that while both techniques can significantly modify the original ground motion, neither technique is consistently more conservative than the other. Therefore, a general conclusion that a particular technique results in ground motions that yield the largest intensity parameters cannot be made a priori.
Pounding of San Francisco-Type Soft-Story Corner Buildings
Authors: Maison Bruce , Bonowitz David , Kornfield Laurence , McCormick David
Published: November 2012

We investigated 1920s-era four-story wood-frame corner buildings common to San Francisco, many of which were damaged in the city's Marina District during the 1989 Loma Prieta earthquake. Such buildings can have relatively weak and flexible first stories and are referred to as soft-story buildings. We calibrated two building computer models to simulate actual earthquake response. We then performed computer analysis to assess collapse performance under 22 hypothetical pounding situations of both as-built and retrofitted soft-story buildings. For this building type, we found that a typical pounding situation increased the collapse rate by 14%, and for retrofitted versions, pounding slightly decreased the collapse rate. However, there were factors that appear to significantly increase the rate, especially in combination: negligible building separations and multiple adjacent buildings having low effective damping and large mass. Based on the results, we outline an approximate way to account for pounding within the context of current design procedures. An upper bound on the pounding effect was found to be equivalent to about a 30% increase in demand.
Pushover and Seismic Response of Foundations on Stiff Clay: Analysis with P-Delta Effects
Authors: Panagiotidou Andriani I. , Gazetas George , Gerolymos Nikos
Published: November 2012

Finite-element analyses are performed for the response to lateral monotonic, slow-cyclic, and seismic loading of rigid footings carrying tall slender structures and supported on stiff clay. The response involves mainly footing rotation under the action of overturning moments from the horizontal external force on—or the developing inertia at—the mass of the structure, as well as from the aggravating contribution of its weight (P-delta effect). Emphasis is given to the conditions for collapse of the soil-foundation-structure system. Two interconnected mechanisms of nonlinearity are considered: detachment from the soil with subsequent uplifting of the foundation (geometric nonlinearity) and formation of bearing-capacity failure surfaces (material inelasticity). The relation between monotonic behavior (static “pushover”), slow-cyclic behavior, and seismic response is explored parametrically. We show that with “light” structures uplifting is the dominant mechanism that may lead to collapse by dynamic instability (overturning), whereas “very heavy” structures mobilize soil failure mechanisms, leading to accumulation of settlement, residual rotation, and ultimately collapse.
A Critical Look at the Use of Design Spectrum Shape for Seismic Risk Assessment
Authors: Erduran Emrah , Lindholm Conrad
Published: November 2012

The effects of using design spectrum shape over actual response spectra on earthquake damage estimates has been investigated. A series of numerical simulations were conducted to estimate the expected damage. The simulations were conducted with four different spectral shapes, two different ground-motion prediction equations (GMPEs) and three different soil classes. As a result of the numerical simulations, it was observed that the use of design spectrum shape leads to over- or underestimation of damage estimates relative to those obtained from the actual spectrum computed using GMPE. The damage estimates were observed to be sensitive to the selected design spectrum shape, the GMPE used to compute the spectral values, the soil type, and the fundamental period of the building typology. It was also observed that Eurocode- and IBC-type design spectrum shapes led to significantly different damage estimates compared to one another.
Developing Regional Building Inventories: Lessons from the Field
Authors: Anagnos Thalia , Comerio Mary C. , Goulet Christine , May Peter J. , Greene Marjorie , McCormick David L. , Bonowitz David
Published: November 2012

Between 2008 and 2011 members of the Concrete Coalition completed numerous building inventories of California cities to assemble a database of California pre-1980 concrete buildings. Inventory collectors used a variety of data sources ranging from county assessors' files to Sanborn maps and satellite images. Sidewalk surveys were used to corroborate data collected from multiple sources, and a regression model was developed to extrapolate data to cities where detailed inventory collection was not possible. Lessons drawn from the inventories of three cities—Alameda, Los Angeles, and San Francisco—indicate that no single approach can be recommended, but instead, the approach depends on many things, including city size, building stock, available budget, available data, and the availability and experience of human resources. Regardless of approach, inventory data is a valuable resource for developing loss estimates and policy recommendations.
Experimental Evaluation of the In-Plane Stiffness of Timber Diaphragms
Authors: Brignola Anna , Pampanin Stefano , Podestà Stefano
Published: November 2012

The seismic response of unreinforced masonry (URM) buildings, in both their as-built or retrofitted configuration, is strongly dependent on the characteristics of wooden floors and, in particular, on their in-plane stiffness and on the quality of wall-to-floor connections. As part of the development of alternative performance-based retrofit strategies for URM buildings, experimental research has been carried out by the authors at the University of Canterbury, in order to distinguish the different elements contributing to the whole diaphragm's stiffness. The results have been compared to the ones predicted through the use of international guidelines in order to highlight shortcomings and qualities and to propose a simplified formulation for the evaluation of the stiffness properties.
Using Collapse Risk Assessments to Inform Seismic Safety Policy for Older Concrete Buildings
Authors: Liel Abbie B. , Deierlein Gregory G.
Published: November 2012

For many in the engineering community, nonductile concrete buildings are the next priority for seismic safety legislation in California. The history of such policies shows that implementation has been challenged by the high costs of seismic retrofit, opposition from building owners, and difficulty in defining and evaluating seismic safety standards. As a result, seismic legislation for existing buildings has developed in response to major earthquakes, rather than through proactive risk assessment. Advances in performance-based earthquake engineering provide a consistent framework for assessing building collapse risk using nonlinear dynamic analysis. These tools are applied to evaluate the risk of earthquake-induced collapse and fatalities in a representative set of older concrete frames. Results show that nonductile concrete frame buildings are about 35 times more likely to collapse in earthquakes than their modern counterparts. These assessments are used to investigate the impact of policy alternatives for seismic mitigation of nonductile concrete buildings.
Seismic Performance of Story Drift–Controlled RC Frames with Hysteretic Dampers
Authors: Oviedo-Amezquita Juan Andres , Midorikawa Mitsumasa , Asari Tetsuhiro
Published: November 2012

This paper investigates the seismic performance of story drift–controlled reinforced concrete (RC) frames with hysteretic dampers. The frame models include a wide range of mechanical properties of dampers, which are defined according to a proportion rule in order to explicitly control the yield story drift of dampers. The story drift response, hysteretic energy dissipation and other parameters are examined to evaluate the effectiveness of dampers. The influence of the global flexural deformation of the frame on the response of dampers is also examined, and an analytical procedure to account for this phenomenon is developed. The obtained results indicate that the seismic performance of the structure is improved by reducing the story drift demand and seismic damage uniformly over the building height. Regarding the global flexural deformation, the proposed analytical procedure can be used for a preliminary estimation of the story number up to which dampers yield before the RC frame.
The Cunningham-Geelen Method in Practice: Branch-Decompositions and Integer Programming
Authors: Margulies S. , Ma J. , Hicks I. V.
Published: November 2012

In 2007, W. H. Cunningham and J. Geelen describe an algorithm for solving [Formula: see text], where [Formula: see text], [Formula: see text], and [Formula: see text], which utilizes a branch-decomposition of the matrix A and techniques from dynamic programming. In this paper, we report on the first implementation of the CG algorithm and compare our results with the commercial integer programming software Gurobi. Using branch-decomposition trees produced by heuristics and optimal trees produced by algorithms developed in our previous studies, we test both a memory-intensive and low-memory version of the CG algorithm on problem instances such as graph 3-coloring, set partition, market split, and knapsack. We isolate a class of set partition instances where the CG algorithm runs twice as fast as Gurobi, and demonstrate that certain infeasible market split and knapsack instances with width ≤6 range from running twice as fast as Gurobi, to running in a matter of minutes versus a matter of hours.
Construction of Risk-Averse Enhanced Index Funds
Authors: Lejeune Miguel A. , Samatlı-Paç Gülay
Published: November 2012

We propose a partial replication strategy to construct risk-averse enhanced index funds. Our model takes into account the parameter estimation risk by defining the asset returns and the return covariance terms as random variables. The variance of the index fund return is required to be below a low-risk threshold with a large probability, thereby limiting the market risk exposure of the investors. The resulting stochastic integer problem is reformulated through the derivation of a deterministic equivalent for the risk constraint and the use of a block decomposition technique. We develop an exact outer approximation method based on the relaxation of some binary restrictions and the reformulation of the cardinality constraint. The method provides a hierarchical organization of the computations with expanding sets of integer-restricted variables and outperforms the Bonmin and the CPLEX solvers. The method can solve large instances (up to 1,000 securities), converges fast, scales well, and is general enough to be applicable to problems with buy-in-threshold constraints.
An Efficient Approach for Solving Reliable Facility Location Models
Authors: Aboolian Robert , Cui Tingting , Shen Zuo-Jun Max
Published: November 2012

We consider reliable facility location models in which facilities are subject to unexpected failures, and customers may be reassigned to facilities other than their regular facilities. The objective is to minimize the total expected costs in normal and failure scenarios. We allow facilities to have different failure rates and do not limit the number of facilities that might be assigned to a customer. Lower bounds for reliable uncapacitated fixed-charge location problem (RUFLP) are derived and used to introduce a class of efficient algorithms for solving the RUFLP problem.
Kagawa Kyōko—A New Look at Japan’s “Most Unassuming Star”
Authors: Ehrlich Linda C. , Yoskiko Kishi
Published: November 2012

This article will discuss the actress Kagawa Kyōko, Kyōko has appeared in some of the greatest Japanese films, starring opposite such luminaries as Mifune Toshirō, Tanaka Kinuyo, and Hasegawa Kazuo, although still her name is not as well known outside of Japan as that
of some of her contemporaries. In a career that has spanned 50 years, she has appeared in close to 120 films. In 1998 she received the Shiju Hoshō award from the Emperor, an award given in the fields of art and scholarship. Many of her films have won awards in Japan (Mother, Inazuma,
Tokyo Story have all figured into the Best Ten of the Kinema Jumpō awards). Talking to her is like watching a large portion of the history of Japanese cinema pass before one’s eyes.
Korean Animation: From Adolescence to Adulthood, 1998-2003
Authors: Lent John A.
Published: November 2012

This article will discuss the growth of Korean animation. A 1994 study reported that animation was Korea’s most important cultural export. The government has primed the industry with many incentives—initially, changing animation’s status from service to manufacturing
which amounted to a 20 percent tax break, launching the Seoul International Cartoon and Animation Festival, and inaugurating the first annual Korean animation awards, all in 1995 (see Lent and Yu, 2001), and later, providing subsidies and awards to animators and other financial assistance
for the creation of centers, libraries, museums, and schools
Contesting Diasporic Subjectivity: James Lee, Malaysian Independent Filmmaker
Authors: Khoo Gaik Cheng
Published: November 2012

This short paper, will posit that James Lee’s work defies Chineseness and Malaysianness, just as both ethnic boundaries and national politics serve to enframe, locate, or marginalize subjects. Indeed, a study of Lee’s work reveals Lee as the prototypical independent Malaysian
filmmaker who is influenced by numerous filmmakers outside of Malaysia.
The Lazy Gaze: The Aesthetics of Consumerism in Itami Jūzō’s Tampopo
Authors: Isles Timothy
Published: November 2012

Tampopo represents a confident expression of postmodern aesthetics, in that through parody, pastiche, and play it is able to capture what would otherwise be a fickle and easily-bored audience, and thus through this act of abduction, it is able to convince that audience at least to receive
its message. What that message may be we shall see. First, we shall consider the features of this film which facilitate its project.
Theorizing Intervention: The Presence of Hong Kong Cinema in Asian America
Authors: Lee Suzie J.
Published: November 2012

This paper addresses the disavowal of Asian American subjectivity by America popular culture and American national history, but focuses on the attempts made by Asian Americans to counter and revise the characterization of Asians as outside the American nation. In the process of intervening
in the formation of the American nation that has historically excluded Asians, we must confront how Asian America is being defined. We must analyze the result of that labor. Ultimately, we must ask the question: does Asian America exist outside a racial nationalist framework in the ways in
which we have tried to address the oppression of Asians in the United States?
A Study of Characteristics of the Windowing Method of Distributing Korean Independent Movies
Authors: Kim Hoonseok , Hyun Daiwon
Published: November 2012

In this study, we have examined and analyzed 344 short films shown on three main programs of network television between March 1995 and October 2002. Among a variety of distributing windows, the first logic for choosing the network was the quality. Second, we have concluded that, in
this analysis, it is important to target those shown on TV because the TV window has been relatively stable and constitutes a large portion of the overall profit of independent films (Kwak, 2002; Kim, J., 1998).
The Question of the Nation in Contemporary Chinese Film: An Introduction
Authors: Lupke Christopher
Published: November 2012

The government of the People’s Republic of China is committed to a policy of irredentism with regard to Taiwan, and Taiwan, for its part, seems at best interested in maintaining the status quo and, increasingly over time, more inclined toward all out separation from the Mainland
when it comes to matters of State. Yet there is little pondering of this problem in Chinese cultural studies. The four articles in this symposium do not all explicitly address the problem of the nation in Chinese film to the exclusion of other themes, but they do implicitly engage this issue
as they endeavor to parse the work of filmmakers from the liang’an sandi of the PRC, Hong Kong, and Taiwan.
Monogamorphous Desires, Faltering Forms: Structure, Content, and Contradiction in The Personals (Zhenghun Qishi) (Taiwan, 1998)
Authors: Kaldis Nick
Published: November 2012

In this essay, I will argue that there is a formal contradiction at the heart of The Personals: the intensely serious content and austere presentation of Du’s private life stand in striking opposition to the comical content and playful presentation of her interviews with prospective
suitors. Following this, I explore the desires underlying this contradiction, and contextualized the film’s representational strategies and within contemporary discourses of gender and sexuality. I follow this with a brief discussion of the film’s generic qualities, namely resonances
between The Personals and some similarly-structured Taiwan films of recent years. Finally, I conclude with information on the film’s marketing strategy and international circulation.
The Muted Interstices of Testimony: A City of Sadness and the Predicament of Multiculturalism in Taiwan
Authors: Lupke Christopher
Published: November 2012

What I plan to do in this essay is to discuss in a broad fashion some of the tendencies that define the style of Hou Hsiao-hsien and then to indicate how they are brought to bear in the representation of the political repression which forms the historical subtext for Hou’s A City
of Sadness. I suggest that ultimately it is precisely the defining characteristics of this important film, the characteristics that make it worth repeated viewing and discussion and have ensured it a venerated status.
Play and Being Playful: The Quotidian in Cinematic Remembrance of the Mao Era
Authors: Liu Xinmin
Published: November 2012

This article will discuss the memoirs of China’s political past in film. Such films have a tendency to reminisce those unforgiving times by way of one’s childhood and adolescence as if, when placed against the fuzzy, gullible, and playful humdrum of childhood, one could
feel less depressed and offended about them. Is the turn towards everyday life a backlash against indiscriminate or even a disingenuous indictment of the Cultural Revolution, or a postmodern trivialization of political traumas, or a mere rhetorical homage paid to the quotidian as the trendsetter?
Chinese Cinema at the Millennium (Part One)
Authors: Chan Evans
Published: November 2012

A spectre is haunting the new millennium — the spectre of ….China. Have the powers of old entered an alliance to exorcise this spectre? It’s been referred to as a “gigantic sucking noise” — sucking jobs from nations both poor and rich.This is the
background to the contemporary interest in Chinese cinema. The genealogy of the impact exerted by the three Chinese cinemas — Hong Kong, Taiwan, and Peoples’ Republic of China — on the global consciousness is subtle, complex, and intertwined, beginning probably with the low-end
transmission of Hong Kong’s Bruce Lee movies in the 1970s. This is part one of an essay titled, “Chinese Cinema at the Millennium,” which will appear in its entirety in an anthology titled, Chinese Connections: Critical Perspectives on Film, Identity and Diaspora, co-edited
by Peter X.Feng, Gina Marchetti, and Tan See-Kam, to be published by Temple University Press in Spring 2004. My special thanks to Marina Heung for her critique and to Gina Marchetti for her invitation to write this essay.
Immersion in the ‘Maximum City’? Interactivity, kinaesthetics and notions of embodiment in Slumdog Millionaire (2008)
Authors: Krstic Igor
Published: November 2012

Danny Boyle’s Slumdog Millionaire (2008) has been criticized for its lack of authenticity, plausibility and realism. Another frequently appearing critique of numerous re/viewers revolved around the issue of ‘poorism’; the film’s alleged deployment of an orientalist
Western gaze in depicting the dirty underbelly of a megacity in the developing world. Instead of asking whether Slumdog Millionaire‘represents’ Mumbai and its urban poor in a realistic or non-realistic (orientalist) way, this article tries to inquire whether and how the film engages
its spectators into a visceral, sensual viewing experience. The article presents an analysis of the film’s deployment of participatory narrative strategies, kinaesthetic cinematography and notions of embodiment, in order to inquire the filmmaker’s overall ambition to immerse viewers
into the experience of living in contemporary Mumbai.
Soluble Aβ Promotes Wild-Type Tau PathologyIn Vivo
Authors: Chabrier Meredith A. , Blurton-Jones Mathew , Agazaryan Andranik A. , Nerhus Joy L. , Martinez-Coria Hilda , LaFerla Frank M.
Published: November 2012

Growing evidence suggests that soluble Aβ species can drive Alzheimer disease (AD) pathogenesis by inducing a cascade of events including tau hyperphosphorylation, proteasome impairment, and synaptic dysfunction. However, these studies have relied largely onin vitroapproaches to examine the role of soluble Aβ in AD. In particular, it remains unknown whether soluble Aβ oligomers can facilitate the development of human wild-type tau pathologyin vivo. To address this question, we developed a novel transgenic model that expresses low levels of APP with the Arctic familial AD mutation to enhance soluble Aβ oligomer formation in conjunction with wild-type human tau. Using a genetic approach, we show that reduction of β-site APP cleaving enzyme (BACE) in these ArcTau mice decreases soluble Aβ oligomers, rescues cognition, and, more importantly, reduces tau accumulation and phosphorylation. Notably, BACE reduction decreases the postsynaptic mislocalization of tau in ArcTau mice and reduces the association between NMDA receptors and PSD-95. These studies provide criticalin vivoevidence for a strong mechanistic link between soluble Aβ, wild-type tau, and synaptic pathology.
Morphine Epigenomically Regulates Behavior through Alterations in Histone H3 Lysine 9 Dimethylation in the Nucleus Accumbens
Authors: Sun HaoSheng , Maze Ian , Dietz David M. , Scobie Kimberly N. , Kennedy Pamela J. , Damez-Werno Diane , Neve Rachael L. , Zachariou Venetia , Shen Li , Nestler Eric J.
Published: November 2012

Dysregulation of histone modifying enzymes has been associated with numerous psychiatric disorders. Alterations in G9a (Ehmt2), a histone methyltransferase that catalyzes the euchromatic dimethylation of histone H3 at lysine 9 (H3K9me2), has been implicated recently in mediating neural and behavioral plasticity in response to chronic cocaine administration. Here, we show that chronic morphine, like cocaine, decreases G9a expression, and global levels of H3K9me2, in mouse nucleus accumbens (NAc), a key brain reward region. In contrast, levels of other histone methyltransferases or demethylases, or of other methylated histone marks, were not affected in NAc by chronic morphine. Through viral-mediated gene transfer and conditional mutagenesis, we found that overexpression of G9a in NAc opposes morphine reward and locomotor sensitization and concomitantly promotes analgesic tolerance and naloxone-precipitated withdrawal, whereas downregulation of G9a in NAc enhances locomotor sensitization and delays the development of analgesic tolerance. We identified downstream targets of G9a by providing a comprehensive chromatin immunoprecipitation followed by massively parallel sequencing analysis of H3K9me2 distribution in NAc in the absence and presence of chronic morphine. These data provide novel insight into the epigenomic regulation of H3K9me2 by chronic morphine and suggest novel chromatin-based mechanisms through which morphine-induced addictive-like behaviors arise.
Increased Bilateral Frontal Connectivity during Working Memory in Young Adults under the Influence of a Dopamine D1 Receptor Antagonist
Authors: Rieckmann Anna , Karlsson Sari , Fischer Håkan , Bäckman Lars
Published: November 2012

Increased frontal bilaterality in old compared with young adults during cognitive performance is a common finding in human functional neuroimaging studies. Age-related reductions in laterality are a widely debated topic and their origins and consequences may be manifold. The current study demonstrates that a dopamine (DA) D1 antagonist induces increased frontal bilateral connectivity in healthy young adults revealed by functional magnetic resonance imaging during a spatial working memory task. Moreover, increases in functional connectivity between right and left prefrontal cortex during the pharmacological challenge were associated with maintaining performance on drug. To our knowledge, this is the first study to pharmacologically induce increased frontal bilateral functional connectivity during a cognitive task in young adults and to show that increased bilaterality is associated with less severe cognitive impairment under the influence of a DA receptor antagonist.
Inactivation ofSocs3in the Hypothalamus Enhances the Hindbrain Response to Endogenous Satiety Signals via Oxytocin Signaling
Authors: Matarazzo Valéry , Schaller Fabienne , Nédélec Emmanuelle , Benani Alexandre , Pénicaud Luc , Muscatelli Françoise , Moyse Emmanuel , Bauer Sylvian
Published: November 2012

Leptin is an adipocyte-derived hormone that controls energy balance by acting primarily in the CNS, but its action is lost in common forms of obesity due to central leptin resistance. One potential mechanism for such leptin resistance is an increased hypothalamic expression of Suppressor of cytokine signaling 3 (Socs3), a feedback inhibitor of the Jak-Stat pathway that prevents Stat3 activation. Ample studies have confirmed the important role of Socs3 in leptin resistance and obesity. However, the degree to which Socs3 participates in the regulation of energy homeostasis in nonobese conditions remains largely undetermined. In this study, using adult mice maintained under standard diet, we demonstrate thatSocs3deficiency in the mediobasal hypothalamus (MBH) reduces food intake, protects against body weight gain, and limits adiposity, suggesting that Socs3 is necessary for normal body weight maintenance. Mechanistically, MBH Socs3-deficient mice display increased hindbrain sensitivity to endogenous, meal-related satiety signals, mediated by oxytocin signaling. Thus, oxytocin signaling likely mediates the effect of hypothalamic leptin on satiety circuits of the caudal brainstem. This provides an anatomical substrate for the effect of leptin on meal size, and more generally, a mechanism for how the brain controls short-term food intake as a function of the energetic stores available in the organism to maintain energy homeostasis. Any dysfunction in this pathway could potentially lead to overeating and obesity.
Population Rate Dynamics and Multineuron Firing Patterns in Sensory Cortex
Authors: Okun Michael , Yger Pierre , Marguet Stephan L. , Gerard-Mercier Florian , Benucci Andrea , Katzner Steffen , Busse Laura , Carandini Matteo , Harris Kenneth D.
Published: November 2012

Cortical circuits encode sensory stimuli through the firing of neuronal ensembles, and also produce spontaneous population patterns in the absence of sensory drive. This population activity is often characterized experimentally by the distribution of multineuron “words” (binary firing vectors), and a match between spontaneous and evoked word distributions has been suggested to reflect learning of a probabilistic model of the sensory world. We analyzed multineuron word distributions in sensory cortex of anesthetized rats and cats, and found that they are dominated by fluctuations in population firing rate rather than precise interactions between individual units. Furthermore, cortical word distributions change when brain state shifts, and similar behavior is seen in simulated networks with fixed, random connectivity. Our results suggest that similarity or dissimilarity in multineuron word distributions could primarily reflect similarity or dissimilarity in population firing rate dynamics, and not necessarily the precise interactions between neurons that would indicate learning of sensory features.
Glutamate Corelease Promotes Growth and Survival of Midbrain Dopamine Neurons
Authors: Fortin Guillaume M. , Bourque Marie-Josée , Mendez Jose Alfredo , Leo Damiana , Nordenankar Karin , Birgner Carolina , Arvidsson Emma , Rymar Vladimir V. , Bérubé-Carrière Noémie , Claveau Anne-Marie , Descarries Laurent , Sadikot Abbas F. , Wallén-Mackenzie Åsa , Trudeau Louis-Éric
Published: November 2012

Recent studies have proposed that glutamate corelease by mesostriatal dopamine (DA) neurons regulates behavioral activation by psychostimulants. How and when glutamate release by DA neurons might play this role remains unclear. Considering evidence for early expression of the type 2 vesicular glutamate transporter in mesencephalic DA neurons, we hypothesized that this cophenotype is particularly important during development. Using a conditional gene knock-out approach to selectively disrupt theVglut2gene in mouse DA neurons, we obtainedin vitroandin vivoevidence for reduced growth and survival of mesencephalic DA neurons, associated with a decrease in the density of DA innervation in the nucleus accumbens, reduced activity-dependent DA release, and impaired motor behavior. These findings provide strong evidence for a functional role of the glutamatergic cophenotype in the development of mesencephalic DA neurons, opening new perspectives into the pathophysiology of neurodegenerative disorders involving the mesostriatal DA system.
Convergent Effects of Acute Stress and Glucocorticoid Exposure upon MAO-A in Humans
Authors: Soliman Alexandra , Udemgba Chinelo , Fan Ian , Xu Xin , Miler Laura , Rusjan Pablo , Houle Sylvain , Wilson Alan A. , Pruessner Jens , Ou Xiao-Ming , Meyer Jeffrey H.
Published: November 2012

Monoamine oxidase-A (MAO-A), a key brain enzyme which metabolizes monoamines, is implicated in the pathophysiology of stress-related illnesses, including major depressive disorder, addiction, and violent behavior. Chronic stressors and glucocorticoid-administration typically associate with elevated MAO-A levels/activity. However, the relationship of shorter stress or glucocorticoid exposures and MAO-A levels/activity is not well established. Our objectives are to assess effects of acute stress upon MAO-AVT,an index of MAO-A density, in human brain and acute glucocorticoid exposure upon MAO-A levels in human neuronal and glial cell lines. Twelve healthy, non-smoking participants aged 18–50 underwent [11C]harmine positron emission tomography to measure brain MAO-AVTon two different days: One under acute psychosocial stress (via Trier Social Stress and Montreal Imaging Stress Tasks) and one under a non-stress condition. MAO-A density (by Western blot) and activity (by [14C]-5-HT metabolism and liquid scintillation spectroscopy) were measured in human neuronal and glial cell lines after 4 h exposure to dexamethasone. We observed a significant reduction in whole-brain MAO-A binding as reflected by reductions in 10 of 11 brain regions. Acute dexamethasone exposure in neuronal and glial cells significantly decreased MAO-A activity and protein levels. We observed a highly consistent relationship between acute stressors and glucocorticoid administration and decreased MAO-A binding, activity and protein levels. Since MAO-A metabolizes monoamines, this phenomenon may explain why acute stressors benefit healthy animals even though chronic stress is associated with illness.
Retrograde Changes in Presynaptic Function Driven by Dendritic mTORC1
Authors: Henry Fredrick E. , McCartney Amber J. , Neely Ryan , Perez Amanda S. , Carruthers Cynthia J. L. , Stuenkel Edward L. , Inoki Ken , Sutton Michael A.
Published: November 2012

Mutations that alter signaling through the mammalian target of rapamycin complex 1 (mTORC1), a well established regulator of neuronal protein synthesis, have been linked to autism and cognitive dysfunction. Although previous studies have established a role for mTORC1 as necessary for enduring changes in postsynaptic function, here we demonstrate that dendritic mTORC1 activation in rat hippocampal neurons also drives a retrograde signaling mechanism promoting enhanced neurotransmitter release from apposed presynaptic terminals. This novel mode of synaptic regulation conferred by dendritic mTORC1 is locally implemented, requires downstream synthesis of brain-derived neurotrophic factor as a retrograde messenger, and is engaged in an activity-dependent fashion to support homeostatictrans-synaptic control of presynaptic function. Our findings thus reveal that mTORC1-dependent translation in dendrites subserves a unique mode of synaptic regulation, highlighting an alternative regulatory pathway that could contribute to the social and cognitive dysfunction that accompanies dysregulated mTORC1 signaling.
Genetic Mechanisms Mediating Kisspeptin Regulation of GnRH gene Expression
Authors: Novaira Horacio J. , Fadoju Doris , Diaczok Daniel , Radovick Sally
Published: November 2012

Kisspeptins (Kiss) have been shown to be key components in the regulation of gonadotropin-releasing hormone (GnRH) secretion.In vitrostudies have demonstrated an increase in GnRH gene expression by Kiss suggesting regulation of GnRH at both the secretory and pretranslational levels. Here, we define genetic mechanisms that mediate Kiss action on target gene expression.In vitro, sequential deletions of the mouse GnRH (mGnRH) gene promoter fused to the luciferase (LUC) reporter gene localized at kisspeptin-response element (KsRE) between −3446 and −2806 bp of the mGnRH gene.In vivo, transgenic mice bearing sequential deletions of the mGnRH gene promoter linked to the LUC reporter localized an identical KsRE. To define the mechanism of regulation, Kiss was first shown to induce nucleosome-depleted DNA within the KsRE, and a potential binding site for the transcription factor, Otx-2, was revealed. Furthermore, increased Otx-2 mRNA, protein, and binding to the KsRE after Kiss treatment were demonstrated. In conclusion, this work identified elements in GnRH-neuronal cell lines and in transgenic mice that mediate positive regulation of GnRH by Kiss. In addition, we show for the first time that Otx-2 is regulated by Kiss, and plays a role in mediating the transcriptional response of mGnRH gene.
Nostril-Specific Olfactory Modulation of Visual Perception in Binocular Rivalry
Authors: Zhou Wen , Zhang Xiaomeng , Chen Jennifer , Wang Li , Chen Denise
Published: November 2012

It is known that olfaction and vision can work in tandem to represent object identities. What is yet unclear is the stage of the sensory processing hierarchy at which the two types of inputs converge. Here we study this issue through a well established visual phenomenon termed binocular rivalry. We show that smelling an odor from one nostril significantly enhances the dominance time of the congruent visual image in the contralateral visual field, relative to that in the ipsilateral visual field. Moreover, such lateralization-based enhancement extends to category selective regions so that when two images of words and human body, respectively, are engaged in rivalry in the central visual field, smelling natural human body odor from the right nostril increases the dominance time of the body image compared with smelling it from the left nostril. Semantic congruency alone failed to produce this effect in a similar setting. These results, taking advantage of the anatomical and functional lateralizations in the olfactory and visual systems, highlight the functional dissociation of the two nostrils and provide strong evidence for an object-based early convergence of olfactory and visual inputs in sensory representations.
Stimulus-Related Activity during Conditional Associations in Monkey Perirhinal Cortex Neurons Depends on Upcoming Reward Outcome
Authors: Ohyama Kaoru , Sugase-Miyamoto Yasuko , Matsumoto Narihisa , Shidara Munetaka , Sato Chikara
Published: November 2012

Acquiring the significance of events based on reward-related information is critical for animals to survive and to conduct social activities. The importance of the perirhinal cortex for reward-related information processing has been suggested. To examine whether or not neurons in this cortex represent reward information flexibly when a visual stimulus indicates either a rewarded or unrewarded outcome, neuronal activity in the macaque perirhinal cortex was examined using a conditional-association cued-reward task. The task design allowed us to study how the neuronal responses depended on the animal's prediction of whether it would or would not be rewarded. Two visual stimuli, a color stimulus as Cue1 followed by a pattern stimulus as Cue2, were sequentially presented. Each pattern stimulus was conditionally associated with both rewarded and unrewarded outcomes depending on the preceding color stimulus. We found an activity depending upon the two reward conditions during Cue2, i.e., pattern stimulus presentation. The response appeared after the response dependent upon the image identity of Cue2. The response delineating a specific cue sequence also appeared between the responses dependent upon the identity of Cue2 and reward conditions. Thus, when Cue1 sets the context for whether or not Cue2 indicates a reward, this region represents the meaning of Cue2, i.e., the reward conditions, independent of the identity of Cue2. These results suggest that neurons in the perirhinal cortex do more than associate a single stimulus with a reward to achieve flexible representations of reward information.
Excessive Extracellular Volume Reveals a Neurodegenerative Pattern in Schizophrenia Onset
Authors: Pasternak Ofer , Westin Carl-Fredrik , Bouix Sylvain , Seidman Larry J. , Goldstein Jill M. , Woo Tsung-Ung W. , Petryshen Tracey L. , Mesholam-Gately Raquelle I. , McCarley Robert W. , Kikinis Ron , Shenton Martha E. , Kubicki Marek
Published: November 2012

Diffusion MRI has been successful in identifying the existence of white matter abnormalities in schizophreniain vivo. However, the role of these abnormalities in the etiology of schizophrenia is not well understood. Accumulating evidence from imaging, histological, genetic, and immunochemical studies support the involvement of axonal degeneration and neuroinflammation—ubiquitous components of neurodegenerative disorders—as the underlying pathologies of these abnormalities. Nevertheless, the current imaging modalities cannot distinguish neuroinflammation from axonal degeneration, and therefore provide little specificity with respect to the pathophysiology progression and whether it is related to a neurodegenerative process. Free-water imaging is a new methodology that is sensitive to water molecules diffusing in the extracellular space. Excessive extracellular volume is a surrogate biomarker for neuroinflammation and can be separated out to reveal abnormalities such as axonal degeneration that affect diffusion characteristics in the tissue. We applied free-water imaging on diffusion MRI data acquired from schizophrenia-diagnosed human subjects with a first psychotic episode. We found a significant increase in the extracellular volume in both white and gray matter. In contrast, significant signs of axonal degeneration were limited to focal areas in the frontal lobe white matter. Our findings demonstrate that neuroinflammation is more prominent than axonal degeneration in the early stage of schizophrenia, revealing a pattern shared by many neurodegenerative disorders, in which prolonged inflammation leads to axonal degeneration. These findings promote anti-inflammatory treatment for early diagnosed schizophrenia patients.
Presynaptic CaV1.3 Channels Regulate Synaptic Ribbon Size and Are Required for Synaptic Maintenance in Sensory Hair Cells
Authors: Sheets Lavinia , Kindt Katie S. , Nicolson Teresa
Published: November 2012

L-type calcium channels (CaV1) are involved in diverse processes, such as neurotransmission, hormone secretion, muscle contraction, and gene expression. In this study, we uncover a role for CaV1.3a in regulating the architecture of a cellular structure, the ribbon synapse, in developing zebrafish sensory hair cells. By combiningin vivocalcium imaging with confocal and super-resolution structured illumination microscopy, we found that genetic disruption or acute block of CaV1.3a channels led to enlargement of synaptic ribbons in hair cells. Conversely, activating channels reduced both synaptic-ribbon size and the number of intact synapses. Along with enlarged presynaptic ribbons incaV1.3amutants, we observed a profound loss of juxtaposition between presynaptic and postsynaptic components. These synaptic defects are not attributable to loss of neurotransmission, becausevglut3mutants lacking neurotransmitter release develop relatively normal hair-cell synapses. Moreover, regulation of synaptic-ribbon size by Ca2+influx may be used by other cell types, because we observed similar pharmacological effects on pinealocyte synaptic ribbons. Our results indicate that Ca2+influx through CaV1.3 fine tunes synaptic ribbon size during hair-cell maturation and that CaV1.3 is required for synaptic maintenance.
Beta Amyloid-Induced Depression of Hippocampal Long-Term Potentiation Is Mediated through the Amylin Receptor
Authors: Kimura Ryoichi , MacTavish David , Yang Jing , Westaway David , Jhamandas Jack H.
Published: November 2012

Alzheimer's disease (AD) is characterized by accumulation of amyloid-β peptide (Aβ) in the brain regions that subserve memory and cognition. The amylin receptor is a potential target receptor for expression of the deleterious actions of soluble oligomeric Aβ species. We investigated whether the amylin receptor antagonist, AC253, neutralizes the depressant effects of Aβ1–42and human amylin on hippocampal long-term potentiation (LTP). Furthermore, we examined whether depressed levels of LTP observed in transgenic mice, which overexpress amyloid precursor protein (TgCRND8), could be restored with AC253. In mouse hippocampal brain slices, field EPSPs were recorded from the stratum radiatum layer of the CA1 area (cornu ammonis 1 region of the hippocampus) in response to electrical stimulation of Schaeffer collateral afferents. LTP was induced by 3-theta burst stimulation protocols. Aβ1–42(50 nm) and human amylin (50 nm), but not Aβ42–1(50 nm), depressed LTP evoked using both stimulation protocols. Preapplication of AC253 (250 nm) blocked Aβ- and human amylin-induced reduction of LTP without affecting baseline transmission or LTP on its own. In contrast to wild-type controls, where robust LTP is observed, 6- to 12-month-old TgCRND8 mice show blunted LTP that is significantly enhanced by application of AC253. Our data demonstrate that the effects of Aβ1–42and human amylin on LTP are expressed via the amylin receptor, and moreover, blockade of this receptor increases LTP in transgenic mice that show increased brain amyloid burden. Amylin receptor antagonists could serve as potentially useful therapeutic agents in AD.
Consolidated and Labile Odor Memory Are Separately Encoded within theDrosophilaBrain
Authors: Scheunemann Lisa , Jost Eva , Richlitzki Antje , Day Jonathan P. , Sebastian Sujith , Thum Andreas S. , Efetova Marina , Davies Shireen-A. , Schwärzel Martin
Published: November 2012

Memories are classified as consolidated (stable) or labile according to whether they withstand amnestic treatment, or not. In contrast to the general prevalence of this classification, its neuronal and molecular basis is poorly understood. Here, we focused on consolidated and labile memories induced after a single cycle training in theDrosophilaaversive olfactory conditioning paradigm and we used mutants to define the impact of cAMP signals. At the biochemical level we report that cAMP signals misrelated in eitherrutabaga (rut) ordunce(dnc) mutants separate between consolidated anesthesia-resistant memory (ARM) and labile anesthesia-sensitive memory (ASM). Those functionally distinct cAMP signals act within different neuronal populations: while rut-dependent cAMP signals act within Kenyon cells (KCs) of the mushroom bodies to support ASM, dnc-sensitive cAMP signals support ARM within antennal lobe local neurons (LNs) and KCs. Collectively, different key positions along the olfactory circuitry seem to get modified during storage of ARM or ASM independently. A precise separation between those functionally distinct cAMP signals seems mandatory to allocate how they support appropriate memories.