bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential Roles of Vascular Endothelial Growth Factor During Skeletal Muscle Hypertrophy
Authors: Huey Kimberly A.
Published: April 2018

Vascular endothelial growth factor (VEGF) deletion in adult mouse muscle fibers contributes to impaired contractile and muscular adaptations to a hypertrophic stimulus suggesting a critical role in adult muscle growth. This review explores the hypothesis that VEGF is essential for adult muscle growth by impacting inflammatory processes, satellite-endothelial cell interactions, and contractile protein accumulation by functioning within known hypertrophic signaling pathways including insulin-like growth factor-1 (IGF-1-Akt) and Wnt-ß-catenin.
“Making” Your Numbers: Engendering Organizational Control Through a Ritual of Quantification
Authors: Mazmanian Melissa , Beckman Christine M.
Published: April 2018

Numbers such as output controls drive action in organizations, yet we know little about how key numbers are created and take on authority. Using qualitative data from multiple properties managed by a hotel management firm, we find that individuals develop and then become committed to achieving budget goals through a ritual of quantification. The budget numbers serve as output controls for the properties and employees. We find that the strength of the budget number as an undisputed future projection emerges from the ritualistic intertwining of process and normative controls in the course of producing a robust output control. Process controls delineate stages in the budgeting cycle, while normative controls (performative work and emotional investment) operate at each stage, propelling people from one stage to the next while also increasing commitment to both the process and the outcome. The result is a single reified budget number. This ritual of quantification further fosters collective solidarity and an underlying belief in the objective authority of numbers to motivate action, assess success, and drive continuous organizational growth. This work has implications for our understanding of systems of organizational control, rituals of quantification, and the microprocesses supporting the emergence of numbers seen as objective and neutral.
Offline–Online Approximate Dynamic Programming for Dynamic Vehicle Routing with Stochastic Requests
Authors: Ulmer Marlin W. , Goodson Justin C. , Mattfeld Dirk C. , Hennig Marco
Published: April 2018

Although increasing amounts of transaction data make it possible to characterize uncertainties surrounding customer service requests, few methods integrate predictive tools with prescriptive optimization procedures to meet growing demand for small-volume urban transport services. We incorporate temporal and spatial anticipation of service requests into approximate dynamic programming (ADP) procedures to yield dynamic routing policies for the single-vehicle routing problem with stochastic service requests, an important problem in city-based logistics. We contribute to the routing literature as well as to the field of ADP. We combine offline value function approximation (VFA) with online rollout algorithms resulting in a high-quality, computationally tractable policy. Our offline–online policy enhances the anticipation of the VFA policy, yielding spatial and temporal anticipation of requests and routing developments. Our combination of VFA with rollout algorithms demonstrates the potential benefit of using offline and online methods in tandem as a hybrid ADP procedure, making possible higher-quality policies with reduced computational requirements for real-time decision making. Finally, we identify a policy improvement guarantee applicable to VFA-based rollout algorithms, showing that base policies composed of deterministic decision rules lead to rollout policies with performance at least as strong as that of their base policy.
Singbarer Rest: Celans phänomenologische Poetologie
Authors: Gelhard Dorothee
Published: April 2018

Celan was a reader of Husserl’s phenomenology and this had animpact on his poetics. Husserl differentiates between three time conceptions:“Urimpression”, “Retention” and “Protention”. Together they are named “Zeithof”.In Celan’s poetological conception this temporal experience is also expressedin a single word, or poem. Hence remembrance emphasizes in Celan’sphenomenological conception the process of perception itself. When using aspecific word like “Mandel” (almond), Celan indicates what changes “Mandel”underwent in history, from ancient biblical times, via the Russian writer OsipMandel’stam to Auschwitz. In Celan’s poetics, words are therefore always ontheir way to another meaning, finally to another person.
Valérys Namen: Der Status des Lesers in derpoésie pure
Authors: Humphreys-Schottmann Franziska
Published: April 2018

Valéry’s dream of the creation of a poésie pure is determined by afundamental tension between two contradictory aspirations. On the one hand,he inherits French rationalism when he tries to develop a poetical praxis basedon a logical-mathematical calculus, in which anything vague and unclear shoulddisappear. On the other hand, this strictly formalized language revolves aroundthe notion of moi pur and therefore subscribes to a hypertrophied subjectivism.The paradoxical logic of personal pronouns described by Émile Benveniste is atthe origin of Valéry’s project: The moi pur is both, the personal pronoun thatidentifies the concrete speaker and the structural function of the universalinvariant. Ineluctably affected by this pronominal shifting, the reader is, aboveall, at stake in the poéésie pure. In an attempt to unfold the aporetical constructionsresulting from this paradox, this textual analysis focuses on some of themain rhetorical figures of Valpoéry’s work. A close reading of Narcisse parle revealsthe specific moments of permanent self-variation by which the popoésie pureconstantly subverts itself. Poeisis resists any kind of rigid formalism, any subjugationof its rhetorical potential and any attempt to escape the ever-sliding senseof the metaphor. We can thus affirm that the aporias revealed by the popoésie pureevidence hence the conditions of poetical representation itself.
Die zerstreute Erbschaft
Authors: Biti Vladimir
Published: April 2018

How can narrative come to terms with the past in a world hit by trauma was one of the questions most consistently investigated in the work of Walter Benjamin. Pursuing it in various past and present contexts, he gradually reassessed the marginalized literary tradition of narrative strolling along the scene of the crime, rummaging through and collecting of the putative indices. The chaotic execution site, calling its observers and investigators to responsibility toward its heap of ruins, resists sovereign narrative reconstruction of its emergence. The latter is therefore replaced by various conjectures, repeated preparations and hesitating roundabouts which ultimately turn the plot into a kind of a bewildering rebus, neither a story nor a picture. I read Dubravka Ugrešić’s posttraumatic novel The Museum of Unconditional Surrender (1997) within this tradition of narratives that strategically couple the incompatible registers of discursive and visual presentation, trivial and high literature, the beautiful and the sublime, materiality and immateriality with one another. Its discourse is haunted by a multitude of exiled or absolved voices and gazes who do not permit a homogeneous and transparent story. Ugrešić’s narrator is, like Benjamin’s flaneur, obsessed by their summoning resonance stored in the myriad of dissipated fragments of today’s posttraumatic world.
In der Vorhölle
Authors: Küster Burkhart
Published: April 2018

In 1857 Édouard Thierry and Barbey d’Aurevilly enter into the defence of the Fleurs du Mal, arguing that these strange poems are related to Dante’s Divina Commedia, the medieval model serving as a foil to the modern texts. Baudelaire intended to include those two vindicating articles in the third and final edition of his poetry, which seems to indicate that the French poet considered Dante’s work relevant to the understanding of the Fleurs du Mal. When Baudelaire the art critic deals with Doré’s and Delacroix’s visual interpretations of Dante, he underlines the great sadness of the Commedia in words that touch on his spleen, the theme which predominates in the „Limbes“ series of 1850–1851. Baudelaire does not say which passages of the Commedia his poems are referring to, but luckily T.S. Eliot, who admired both Dante and Baudelaire, can help. Eliot mentions lines of the third canto of the Inferno that fuse easily with the „Limbes“ poems. Eliot and other thinkers were fond of the canto which describes the vestibule of Hell.

Up to now, critics have mainly searched for similarities with Baudelaire’s poems in the fourth canto of the Inferno, in Limbo, and have never found much. This article attempts to demonstrate that it is ideas from the third canto of the Inferno that can be conceived as a second voice to the „Limbes“, making the reading of Baudelaire’s early poems a more enriching experience.
Asian-Americans in New York: Two Men’s Adventures in Immigrant-Land
Authors: Chevereşan Cristina
Published: April 2018

Gish Jen’s Typical American and Chang-rae Lee’s Native Speaker are two essentially urban novels that focus on issues of (ethnic) identity construction and performativity in metropolitan New York, at the end of the twentieth century. Belonging to two distinct immigrant communities (Chinese and Korean), their protagonists are Americans in the making, whose personal evolutions and involutions are shaped by the social and cultural dilemmas of transition and (mal)adjustment. The present article scrutinizes the fictional interplay of public and private (hi)stories and discourses, and analyzes the ways in which stereotypical definitions and representations of otherness, investigations and exploitations of memory, and manipulations of individual and communal belief are called upon to illustrate the intricate mechanisms of contemporary United States. Citizenship, ethnicity, education, language, power relations, discrimination, consumerism and, last but not least, politics, are important elements that this comparative approach questions. By studying the two novels together, the article argues that the two writers capture different, yet equally relevant hypostases of the (Asian) immigrant’s self-questioning and self-inscription into the American nation, whose updated versions of the “Dream” have been dominated by the material rather than the spiritual concerns.
Zentrifugen des Wissens – Zur Enzyklopädik des Barockromans
Authors: Kilcher Andreas B.
Published: April 2018

Early modern literature has high epistemological claims. In particular, the novel as the most innovative genre of the 16th and 17th centuries was expected to negotiate and transmit knowledge about the world in an extensive way. This epistemological optimism must be understood against the background of contemporary encyclopaedic models, which offered new possibilities of reaching out for universal and total knowledge. Two variants of encyclopaedic writing are most efficient for the novel: the logic of Lullism and the miscellaneous knowledge production of Polyhistorism. Both techniques were used in baroque novels of the 17th century: Polyhistorism produced a centrifugal dispersion of knowledge throughout the texts, whereas Lullism aimed at recollecting and ordering it. This interplay is evidently present in Daniel Casper von Lohenstein’s highly digressive 3,000 page novel „Arminius“ (1689/90), with its paratextual framework of prefaces, annotations, and indices. Moreover, the reception of „Arminius“ in 18th and 19th centuries is pertinent for the subsequent critique of encyclopaedic knowledge.
Dietmar Daths enzyklopädische Science Fiction
Authors: Willer Stefan
Published: April 2018

In contemporary German literature, Dietmar Dath (born 1970) is arguably the most prolific encyclopaedic author – a designation that refers not only to the amount of scientific, discursive and popular knowledge included in his books, but also to their shere volume. Since the mid-1990s, Dath has published a huge amount of fiction and non-fiction, with manifold transitions between these two categories. I propose to read Dath’s novels – especially „Für immer in Honig“ (2005, revised edition 2008) and „Die Abschaffung der Arten“ (2008) – as encyclopaedic Science Fiction: a kind of literary knowledge presentation that is at the same time extremely polyhistoric, highly entertaining, and strictly progress oriented in the vein of classical Marxism-Leninism. After sketching these programmatic aspects of Dath’s writing, I examine some of his crucial political and scientific issues and the way in which they figure in the aforementioned novels: posthumanism, scientific socialism, and mathematical category theory. To conclude, I discuss Dath’s preoccupation with the narrative integration of the multifarious elements of his writing, which is also the attempt of including them into a coherent narrative of his own authorship.
Ein anderer Pygmalion – Techniken der Kunstbelebung in Joseph von Eichendorffs Das Marmorbild, Oscar Wildes The Picture of Dorian Gray und Georg Heyms Der Dieb
Authors: Genz Julia
Published: April 2018

The main issue of the Pygmalion myth is the vitalisation of an artificial woman. In Ovid’s Metamorphoses it is motivated by the intervention of Venus. This article deals with Pygmalion-like protagonists since 1800, in which the crucial point of vitalisation is no longer based on divine volition but on semiotic theories that Winckelmann, Lessing, Goethe and others used in the eighteenth century. In these cases, the protagonist’s perspective gives rise to the impression of vivification. The examples of Joseph von Eichendorff, Oscar Wilde and Georg Heym show that this shift also had an impact on the narrative techniques, for their concreteness allows the reader to retrace the vivification of the figures himself. In the twentieth century Georg Heym modernised the techniques of the eighteenth century by connecting them with associations of the new medium film. In the course of time the pygmalionic observer turns into a pygmalionic narrator, whose narration obtains with the aid of the reader an enormous vitality.
Problématique du désir et du plaisir chez Honoré de Balzac et Cao Xueqin
Authors: Kan Chia-Ping
Published: April 2018

The issue of ‘desire’ is one that is of deep interest to both Balzac and Cao Xueqin. The purpose of the article is to show that the focus and development of these two authors on the issue of desire present astonishing similarities and a common aim to show that there is no final solution. Instead, there is a similar approach that impacts the entire life of their heroes and can be considered as the cursed part of the human condition. Recognition of desire as the chimera that it is and renouncing the pursuit of its satisfaction could be one solution. Yet is not desire what constitutes being human? Renouncing it could turn out to be as chimerical as the original problem, the hope for its fulfillment.
Transition as a focus within language maintenance research: Wellington Iraqi refugees as an example
Authors: Tawalbeh Ayman
Published: April 2018

Most current language maintenance and shift research has focused on investigating immigrants’ experiences and attitudes in their host countries only. Recent research has shown that additional insights can be gained from a multi-perspective approach to language maintenance that includes “spatio-temporal” frames. Transit experiences (representing extra spaces and multiple phases) offer important information which has been overlooked in most language maintenance and shift research. Drawing on a data set of 30 semi-structured interviews with Wellington Iraqis and 13 with Iraqi refugees preparing to move to New Zealand from their transit point in Jordan, this article argues for the significance of transit experiences to language maintenance research. Analysis of the data suggests the significance of transit experiences in explaining the variations in Iraqis’ linguistic preferences and competencies and elucidates differences in language ability, use and attitude between older and younger generations. The data provides evidence for the importance of transition as a focus within language maintenance and shift study.
Lexical V-V compounds in child Japanese: An experimental study
Authors: Isobe Miwa , Okabe Reiko , Kido Yasuhito
Published: April 2018

Japanese is known to have verbal compounds consisting of two verbs (hereafter “V-V compounds”), and many theoretical studies have shown that V-V compounds can be divided into two types: lexical and syntactic V-V compounds (Kageyama 1993, among many others). A recent study by Kageyama (2013, 2016a, 2016b) points out that the lexical V-V compounds can be further categorized into two types, one of which can be paraphrased as the V-teV sequence. The aim of our current study is to elucidate based on experimental data whether Japanese-speaking children aged 4-5 can correctly comprehend lexical V-V compounds and differentiate them from the V-teV sequence which are superficially similar to but syntactically distinct from them. Our experiment reveals that children can differentiate between the syntactic properties of these constructions and thus have acquired the two different constructions consisting of two-verb sequences by the time they turn 4 years old.
Effect of a multidisciplinary treatment program on eating behavior in overweight and obese preschool children
Authors: Bocca Gianni , Kuitert Mirije W.B. , Sauer Pieter J.J. , Corpeleijn Eva
Published: April 2018

Background:

The effects of multidisciplinary treatment programs on eating behavior in overweight preschool-aged children are largely unknown. We evaluated a multidisciplinary intervention program on eating behavior in 3- to 5-year-old overweight children, comparing them with children given standard treatment. We also assessed the parental eating behavior changes and investigated associations between parents and children.

Methods:

We randomized 75 children to a multidisciplinary intervention or to a standard care program. During a 16-week period, children and parents in the multidisciplinary group were given dietary advice, physical activity sessions and, for parents only, psychological counseling. Children and parents in the standard group visited a pediatrician 3 times and were given information on a healthy lifestyle. At baseline, after 16 weeks, and after 12 months, children were measured and parents completed the Dutch Child Eating Behavior Questionnaire (DEBQ-C) for their children and the DEBQ for themselves.

Results:

At the three time points, 70 (93.3%), 57 (91.9%), and 42 (73.7%) DEBQ-Cs were analyzed. We found no differences in the changes in eating behavior between the two groups over time. In both groups, there was a significant increase in restrained eating behavior present at 16 weeks, however, this was no longer present at 12 months. We found no associations between changes in eating behavior between the children and their parents.

Conclusions:

A multidisciplinary obesity intervention program in preschool-aged children induced more restrained eating behavior between baseline and 16 weeks. However, there was no difference with the children in the standard care group.
Bayesian estimation of ordinary differential equation models when the likelihood has multiple local modes
Authors: Liu Baisen , Wang Liangliang , Cao Jiguo
Published: April 2018

Ordinary differential equations (ODEs) are popularly used to model complex dynamic systems by scientists; however, the parameters in ODE models are
often unknown and have to be inferred from noisy measurements of the dynamic system. One conventional method is to maximize the likelihood function, but the likelihood function often has many local modes due to the complexity of ODEs, which makes the optimizing algorithm be vulnerable to trap in local modes.
In this paper, we solve the global optimization issue of ODE parameters with the help of the Stochastic Approximation Monte Carlo (SAMC) algorithm which is shown to be self-adjusted and escape efficiently from the “local-trapping” problem. Our simulation studies indicate that the SAMC
method is a powerful tool to estimate ODE parameters globally. The efficiency of SAMC method is demonstrated by estimating a
predator-prey ODEs model from real experimental data.
An overview of the synthesis of CuO-ZnO nanocomposite for environmental and other applications
Authors: Das Susmita , Srivastava Vimal Chandra
Published: April 2018

In the field of environmental science, metal oxide nanocomposites have gained a great attention for both theoretical and experimental aspects of their upgradation because of their wide range of practical applications such as catalysts, sensors, hydrogen storages, and optoelectronics. Among all nanocomposites, Copper oxide-zinc oxide (CuO-ZnO) has attracted more research due to their excellent tunable catalytic, electrical, optical, and magnetic properties and environment-friendly nature. Coupling of one metal oxide semiconductor with another metal oxide semiconductor produces an enlarged surface area, which provide more reactive sites, promotes mass transfer, promotes electron transfer, and avoids photo-corrosion of nanocomposites, which enhances its efficiency. The CuO-ZnO nanocomposite has been prepared by various methods such as co-precipitation, sol-gel, wet impregnation, and thermal decomposition. Depending on the preparation method and conditions used, different types of CuO-ZnO nanocomposites like Cu-doped ZnO, Cu supported/impregnated on ZnO, and CuO-ZnO mixed oxides with different morphologies of CuO-ZnO nanocomposites have been obtained. This article reviews the synthesis techniques of the CuO-ZnO nanocomposite and its morphology. Various practical applications of the CuO-ZnO nanocomposites have also been discussed.
“Libre à de plus audacieux de pousser plus loin la fidélité”: Traduire les passages obscènes dans la “Collection des Universités de France” entre 1920 et 1945
Authors: Flamerie de Lachapelle Guillaume
Published: April 2018

This article aims to show how the translators of the Latin series of the “Collection des Universités de France” treated the obscene passages between 1920 and 1945. Some address the issue in their preface; many deliberately avoid a literal translation, either by quite simply refraining from translating the passages concerned, or by relying on a form of euphemisation. Each of these two strategies itself drew on various mechanisms. In the end, the “Collection des Universités de France” is shown to be more precise than older or contemporary bilingual collections, whether in France or in the English-speaking world. Nontheless, from the 1930 s onward Jules Marouzeau criticised the translators for their prudery; progressively, the new translators became more explicit.
Energy dissipation characteristics of crosslinks in natural rubber: an assessment using low and high-frequency analyzer
Authors: Anas K. , David Samson , Babu R.R. , Selvakumar M. , Chattopadhyay S.
Published: April 2018

The dynamic deformation of a viscoelastic material can cause heat generation. This heat generation is an aspect of energy dissipation. The present paper investigates the contribution of crosslink type and density on energy dissipation mechanism in natural rubber compounds. The influences of these elements are investigated using a very high frequency (VHF) analyzer (VHF 104) and a dynamical mechanical analyzer (DMA). The VHF 104 analyzer follows transmissibility and vibration isolation principle, whereas DMA works on dynamical mechanical the deformation principle. Higher crosslink density promotes lower heat generation in rubber compounds. Tan δ interpretation for energy dissipation characteristics of rubbery compounds should be done judiciously to avoid wrong interpretations. Polysulfidic linkages show higher damping ratios (ζ) than monosulfidic or disulfidic linkages due to their dissipative nature. The natural frequency (ω
n) of a system at a given mass is the function of its crosslink density.
Improving the mechanical properties of Fe3O4/carbon nanotube reinforced nanocomposites by a low-magnetic-field induced alignment
Authors: Huang Yifan , Jiao Weicheng , Niu Yue , Ding Guomin , Wang Rongguo
Published: April 2018

The aim of the paper is to develop a novel nanocomposite with high mechanical properties. The mechanical properties are improved by aligning the Fe3O4/multi-walled carbon nanotubes (MWCNTs) into a highly oriented manner in epoxy resin (EP) via a low magnetic field. Fe3O4 nanoparticles were tethered onto the surface of MWCNTs by a novel water-in-oil (W/O) method without heating at high temperatures or the protection of inert gas. Then, the modified magnetic MWCNTs (m-MWCNTs) were added into EP and aligned in a low magnetic field (100 mT). A method was presented to estimate the minimum magnetic field strength for aligning the m-MWCNTs. Besides, the morphology and microstructures of the fabricated m-MWCNTs and m-MWCNTs/EP highly ordered nanocomposites were characterized. Finally, the mechanical properties measurements were performed. The results of the experiments showed that this method was very efficient in aligning m-MWCNTs embedded in polymer matrix leading to a highly ordered composite for improving mechanical properties.
A unique structure of uranyl-carbonate mineral sharpite: a derivative of the rutherfordine topology
Authors: Plášil Jakub
Published: April 2018

The structure of hydrated calcium uranyl carbonate, mineral sharpite, has been solved for the first time. The structure is orthorhombic, space group Cmcm, with the unit-cell parameters a=4.9032 (4), b=15.6489 (11), c=22.0414 (18) Å, V=1691.2 (2) Å3, Z=4. The structure was refined from 858 unique observed reflections to a final R=5.48% (GOF=1.48). The structure is based upon infinite Ca2+-uranyl-carbonate sheets, which are unique among uranyl minerals and inorganic compounds. They result from edge-sharing of triangles, occupied by CO3, and hexagons that are occupied both by UO8 and Ca2+(H2O)3O5. Thus, topology of the sheets is identical to rutherfordine, (UO2)(CO3). Nevertheless Ca2+ is occupying one of the hexagons of the topology in sharpite. Sheets are extremely corrugated, stacked perpendicular to b and linked by H-bonds and Van Der Waals interactions, only. The ideal chemical formula of sharpite is {Ca(H2
[3]O)3[(UO2)3(CO3)3.6O0.2]}0, Z=4; however, one of the C sites was found to be only partially occupied. The character of sharpite structure is probably a key to understand its scarcity of occurrences in Nature.
Design of Multi-Resonant Cavities Based on Metal-Coated Dielectric Nanocylinders
Authors: Dong Junyuan , Yu Guanxia , Fu Jingjing , Luo Min , Du Wenwen
Published: April 2018

In this paper, the light scattering properties for multiple silver-coated dielectric nanocylinders with the symmetrical distribution were investigated. Based on the transfer matrix method, we derive the general transmission and reflection coefficient matrices for multiple dielectric nanocylinders. When the incident light frequencies are less than the plasma frequencies, the surface plasmons (SPs) appear in the interface between the silver and dielectrics. Numerical simulations show that there are three peaks of absorption cross-section (ACS) in the relationship between the ACS and the frequencies of the incident light, when the distance between the silver-coated dielectric nanocylinders is chosen properly. These SPs resonance peaks are characterised as resonances intrinsic to the cylindrically periodic system corresponding to different inner cavity structures. These multi-resonant cavities may have potential applications in integrated devices, optical sensors and optical storage devices.
Triclinic conformational polymorph of N,N,N′,N′-tetrakis(2-cyanoethyl)-1,2-ethylenediamine (TCED)
Authors: Bereska Bartłomiej , Czaja Krystyna , Dziuk Błażej , Zarychta Bartosz , Ejsmont Krzysztof , Iłowska Jolanta , Szmatoła Michał , Bereska Agnieszka
Published: April 2018

The crystal and molecular structures of two polymorphs of N,N,N′,N′-tetrakis(2-cyanoethyl)-1,2-ethylenediamine have been characterized by X-ray diffraction along with density functional theory (DFT) studies. The molecules differ from each other by conformation. N,N,N′,N′-tetrakis(2-cyanoethyl)-1,2-ethylenediamine has been synthesized by cyanoethylation of ethylenediamine. Cyanoethylation of vicinal diamines is important for the synthesis of hyperbranched polymeric materials applied as catalysts, surfactants and encapsulating agents in drug delivery systems. The molecular geometry of N,N,N′,N′-tetracyanoethyl-1,2-ethylenediamine is similar to that of homologous compounds. DFT calculations were performed to analyze the differences in the molecular geometry of the studied compounds in a crystalline state and for an isolated molecule.
Influence of Organic Ligands on the Surface Oxidation State and Magnetic Properties of Iron Oxide Particles
Authors: Goroncy Christian , Saloga Patrick E. J. , Gruner Mathias , Schmudde Madlen , Vonnemann Jonathan , Otero Edwige , Haag Rainer , Graf Christina
Published: April 2018

For the application of iron oxide nanoparticles from thermal decomposition approaches as contrast agents in magnetic resonance imaging (MRI), their initial hydrophobic ligands have to be replaced by hydrophilic ones. This exchange can influence the surface oxidation state and the magnetic properties of the particles. Here, the effect of the anchor group of three organic ligands, citric acid and two catechols, dihydrocaffeic acid and its nitrated derivative nitro dihydrocaffeic acid on iron oxide nanoparticles is evaluated. The oleate ligands of Fe3O4/γ-Fe2O3 nanoparticles prepared by the thermal decomposition of iron oleate were exchanged against the hydrophilic ligands. X-ray absorption spectroscopy, especially X-ray magnetic circular dichroism (XMCD) measurements in the total electron yield (TEY) mode was used to investigate local magnetic and electronic properties of the particles’ surface region before and after the ligand exchange. XMCD was combined with charge transfer multiplet calculations which provide information on the contributions of Fe2+ and Fe3+ at different lattice sites, i.e. either in tetrahedral or octahedral environment. The obtained data demonstrate that nitro hydrocaffeic acid leads to least reduction of the magnetizability of the surface region of the iron oxide nanoparticles compared to the two other ligands. For all hydrophilic samples, the proportion of Fe3+ ions in octahedral sites increases at the expense of the Fe2+ in octahedral sites whereas the percentage of Fe3+ in tetrahedral sites hardly changes. These observations suggest that an oxidation process took place, but a selective decrease of the Fe2+ ions in octahedral sites ions due to surface dissolution processes is unlikely. The citrate ligand has the least oxidative effect, whereas the degree of oxidation was similar for both catechol ligands regardless of the nitro group. Twenty-four hours of incubation in isotonic saline has nearly no influences on the magnetic properties of the nanoparticles, the least on those with the nitrated hydrocaffeic acid ligand.
Alterations in AMPA Receptor Subunit Expression after Experimental Spinal Cord Contusion Injury
Authors: Grossman Stacie D. , Wolfe Barry B. , Yasuda Robert P. , Wrathall Jean R.
Published: April 2018

The AMPA-preferring subtype of ionotropic glutamate receptors (GluRs) is a hetero-oligomeric ion channel assembled from various combinations of four subunits: GluR1, GluR2, GluR3, and GluR4. Antagonists of these receptors can mitigate the effects of experimental spinal cord injury (SCI), indicating that these receptors play a significant role in pathophysiology after spinal trauma. We tested the hypothesis that SCI alters expression of AMPA receptors using a standardized thoracic weight-drop model of rat contusive spinal cord injury. AMPA receptor subunit expression was measured at 24 hr and at 1 month after SCI with quantitative Western blot analysis andin situhybridization. GluR2 protein levels were preferentially reduced near the injury site 24 hr after SCI. This reduction persisted at 1 month. At a cellular level, a significant decrease in both GluR2 and GluR4 mRNA was found in spared ventral motor neurons adjacent to the injury site and distal to it, with other AMPA subunit mRNAs maintained at control levels. In contrast, only GluR1 mRNA was decreased in the sympathetic preganglionic neurons of the intermediolateral horn. These results suggest population-specific and long-lasting changes in neuronal AMPA receptor composition, which may alter response to glutamate after SCI. These alterations may contribute not only to acute neuropathological consequences of injury, but they may also be partially responsible for the altered functional state of preserved tissue seen chronically after SCI.
Potentiation of Quantal Catecholamine Secretion by Glibenclamide: Evidence for a Novel Role of Sulphonylurea Receptors in Regulating the Ca2+Sensitivity of Exocytosis
Authors: Taylor S. C. , Carpenter E. , Roberts M. L. , Peers C.
Published: April 2018

Electrochemical detection of quantal catecholamine release from PC-12 cells revealed that glibenclamide, an inhibitor of ATP-sensitive K+channels, potentiated Ca2+-dependent exocytosis evoked by raised extracellular [K+] and by exposure of cells to caffeine. Glibenclamide was without effect on voltage-gated Ca2+currents, membrane potential, or rises of [Ca2+]ievoked by either raised extracellular [K+] or caffeine. The dependence of K+-evoked secretion on extracellular Ca2+was shifted leftward in the presence of glibenclamide, with a small increase in the plateau level of release, suggesting that glibenclamide primarily increased the Ca2+sensitivity of the exocytotic apparatus. Enhancement of secretion by glibenclamide was reversed by pinacidil and cromakalim, indicating that the effects of glibenclamide were mediated via an action on a sulfonylurea receptor. These results demonstrate that sulfonylurea receptors can modulate Ca2+-dependent exocytosis via a mechanism downstream of Ca2+influx or mobilization.
Glutamate Receptors Mediate TTX-Resistant Synchronous Activity in the Rat Hippocampus
Authors: Strowbridge Ben W.
Published: April 2018

4-Aminopyridine (4-AP) is a well known convulsant that enhances the release of both excitatory and inhibitory neurotransmitters in the CNS. Low concentrations of 4-AP (∼100 μm) readily induce synchronized discharges in the hippocampus that are blocked by tetrodotoxin (TTX), suggesting that they require Na+-dependent action potentials in addition to the enhanced release of neurotransmitters. However, in the present study we have found that higher concentrations of 4-AP (1 mm) in combination with 5 mmtetraethylammonium (TEA) induce spontaneous synchronized discharges in rat hippocampal slices that are resistant to blockade by TTX. These synchronous discharges are evident in field potential recordings, which progress from the hilus to CA1 at 0.023 ± 0.002 m/sec and in intracellular recordings from the hilar mossy cells and CA3 pyramidal cells. In some slices exposed to 4-AP and TEA, smaller-amplitude asynchronous responses also were recorded. 4-AP-induced spontaneous discharges are blocked by 20 μmDNQX and by 100 μmCd2+but are resistant to blockade by either 25 μmbicuculline or 25 μmd-APV. These results suggest that the activation of postsynaptic AMPA receptors is necessary to produce TTX-resistant synchronized discharges. The laminar profile of field potentials recorded in CA3 and CA1 suggests that glutamate is released from axons of CA3 pyramidal cells despite the blockade of fast axonal Na+channels by TTX. Synchronous discharges may result from glutamate released at proximal recurrent collaterals after spontaneous Ca2+spikes in CA3 pyramidal cells.
Supralinear Summation of Synaptic Inputs by an Invertebrate Neuron: Dendritic Gain Is Mediated by an “Inward Rectifier” K+Current
Authors: Wessel Ralf , Kristan William B. , Kleinfeld David
Published: April 2018

Dendritic processing of glutamatergic synaptic inputs was investigated in the anterior pagoda cell of leech. We observed that below spike threshold, the amplitude of individual EPSPs decreased with hyperpolarization and that simultaneous stimulation of pairs of synaptic inputs leads to the supralinear summation of EPSPs. Voltage-clamp measurements revealed a hyperpolarization-activated, Ba2+-sensitive, fast, noninactivating K+conductance that depends on the external [K+]. These features are those of an “inward rectifier,” Kir. Microsurgery experiments, in combination with electrophysiological measurements, revealed an inhomogeneous spatial distribution of the Kir conductance. Furthermore, on surgical removal of the neurites that contain the Kir conductance, the amplitude of EPSPs from the remaining synaptic inputs increased with hyperpolarization. A model cell, with the Kir conductance as the sole voltage-dependent conductance, reproduced qualitatively the observed voltage dependence of individual EPSPs as well as the supralinear summation of EPSP pairs.
Caspase-8 and Caspase-3 Are Expressed by Different Populations of Cortical Neurons Undergoing Delayed Cell Death after Focal Stroke in the Rat
Authors: Velier James J. , Ellison Julie A. , Kikly Kristine K. , Spera Patricia A. , Barone Frank C. , Feuerstein Giora Z.
Published: April 2018

A number of studies have provided evidence that neuronal cell loss after stroke involves programmed cell death or apoptosis. In particular, recent biochemical and immunohistochemical studies have demonstrated the expression and activation of intracellular proteases, notably caspase-3, which act as both initiators and executors of the apoptotic process. To further elucidate the involvement of caspases in neuronal cell death induced by focal stroke we developed a panel of antibodies and investigated the spatial and temporal pattern of both caspase-8 and caspase-3 expression. Our efforts focused on caspase-8 because its “apical” position within the enzymatic cascade of caspases makes it a potentially important therapeutic target. Constitutive expression of procaspase-8 was detectable in most cortical neurons, and proteolytic processing yielding the active form of caspase-8 was found as early as 6 hr after focal stroke induced in rats by permanent middle cerebral artery occlusion. This active form of caspase-8 was predominantly seen in the large pyramidal neurons of lamina V. Active caspase-3 was evident only in neurons located within lamina II/III starting at 24 hr after injury and in microglia throughout the core infarct at all times examined. Terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling, gel electrophoresis of DNA, and neuronal cell quantitation indicated that there was an early nonapoptotic loss of cortical neurons followed by a progressive elimination of neurons with features of apoptosis. These data indicate that the pattern of caspase expression occurring during delayed neuronal cell death after focal stroke will vary depending on the neuronal phenotype.
Shunting versus Inactivation: Analysis of Presynaptic Inhibitory Mechanisms in Primary Afferents of the Crayfish
Authors: Cattaert Daniel , El Manira Abdeljabbar
Published: April 2018

Primary afferent depolarizations (PADs) are associated with presynaptic inhibition in both vertebrates and invertebrates. In the present study, we have used both anatomical and electrophysiological techniques to analyze the relative importance of shunting mechanisms versus sodium channel inactivation in mediating the decrease of action potential amplitude, and thereby presynaptic inhibition. Experiments were performed in sensory afferents of a stretch receptor in anin vitropreparation of the crayfish. Lucifer yellow intracellular labeling of sensory axons combined with GABA immunohistochemistry revealed close appositions between GABA-immunoreactive (ir) fibers and sensory axons. Most contacts were located on the main axon at the entry zone of the ganglion, close to the first branching point within the ganglion. By comparison, the output synapses of sensory afferents to target neurons were located on distal branches. The location of synaptic inputs mediating spontaneous PADs was also determined electrophysiologically by making dual intracellular recordings from single sensory axons. Inputs generating PADs appear to occur around the first axonal branching point, in agreement with the anatomical data. In this region, small PADs (3–15 mV) produced a marked reduction of action potential amplitude, whereas depolarization of the membrane potential by current injection up to 15 mV had no effect. These results suggest that the decrease of the amplitude of action potentials by single PADs results from a shunting mechanism but does not seem to involve inactivation of sodium channels. Our results also suggest that GABAergic presynaptic inhibition may act as a global control mechanism to block transmission through certain reflex pathways.
Glutamate-Triggered Events Inducing Corticostriatal Long-Term Depression
Authors: Calabresi Paolo , Centonze Diego , Gubellini Paolo , Marfia Girolama A. , Bernardi Giorgio
Published: April 2018

Repetitive activation of corticostriatal fibers produces long-term depression (LTD) of excitatory synaptic potentials recorded from striatal spiny neurons. This form of synaptic plasticity might be considered the possible neural basis of some forms of motor learning and memory. In the present study, intracellular recordings were performed from rat corticostriatal slice preparations to study the role of glutamate and other critical factors underlying striatal LTD. In current-clamp, but not in voltage-clamp experiments, brief focal applications of glutamate, as well as high-frequency stimulation (HFS) of corticostriatal fibers, induced LTD. This pharmacological LTD and the HFS-induced LTD were mutually occlusive, suggesting that both forms of synaptic plasticity share common induction mechanisms. Isolated activation of either non-NMDA-ionotropic glutamate receptors (iGluRs) or metabotropic glutamate receptors (mGluRs), respectively by AMPA andt-ACPD failed to produce significant long-term changes of corticostriatal synaptic transmission. Conversely, LTD was obtained after the simultaneous application of AMPA plust-ACPD. Moreover, also quisqualate, a compound that activates both iGluRs and group I mGluRs, was able to induce this form of pharmacological LTD. Electrical depolarization of the recorded neurons either alone or in the presence oft-ACPD and dopamine (DA) failed to mimic the effects of the activation of glutamate receptors in inducing LTD. However, electrical depolarization was able to induce LTD when preceded by coadministration oft-ACPD, DA, and a low dose of hydroxylamine, a compound generating nitric oxide (NO) in the tissue. None of these compounds alone produced LTD. Glutamate-induced LTD, as well as the HFS-induced LTD, was blocked byl-sulpiride, a D2 DA receptor antagonist, and by 7-nitroindazole monosodium salt, a NO synthase inhibitor. The present study indicates that four main factors are required to induce corticostriatal LTD: (1) membrane depolarization of the postsynaptic neuron; (2) activation of mGluRs; (3) activation of DA receptors; and (4) release of NO from striatal interneurons.
An Olfactory Sensory Neuron Line,Odora, Properly Targets Olfactory Proteins and Responds to Odorants
Authors: Murrell Julie R. , Hunter Dale D.
Published: April 2018

The site for interactions between the nervous system and much of the chemical world is in the olfactory sensory neuron (OSN). Odorant receptor proteins (ORPs) are postulated to mediate these interactions. However, the function of most ORPs has not been demonstratedin vivoorin vitro. For this and other reasons, we created a conditionally immortalized cell line derived from the OSN lineage, which we termodora. Odoracells, under control conditions, are phenotypically similar to the OSN progenitor, the globose basal cell. After differentiation,odoracells more closely resemble OSNs. Differentiatedodoracells express neuronal and olfactory markers, including components of the olfactory signal transduction pathway. Unlike other cell lines, they also efficiently target exogenous ORPs to their surface. Strikingly, differentiatedodoracells expressing ORPs respond to odorants, as measured by an influx of calcium. In particular, cells expressing one ORP demonstrate a specific response to only one type of tested odorant.Odoracells, therefore, are ideal models to examine the genesis and function of olfactory sensory neurons.
Human Neuronal γ-Aminobutyric AcidAReceptors: Coordinated Subunit mRNA Expression and Functional Correlates in Individual Dentate Granule Cells
Authors: Brooks-Kayal Amy R. , Shumate Melissa D. , Jin Hong , Lin Dean D. , Rikhter Tatiana Y. , Holloway Kathryn L. , Coulter Douglas A.
Published: April 2018

γ-Aminobutyric acidAreceptors (GABARs) are heteromeric proteins composed of multiple subunits. Numerous subunit subtypes are expressed in individual neurons, which assemble in specific preferred GABAR configurations. Little is known, however, about the coordination of subunit expression within individual neurons or the impact this may have on GABAR function. To investigate this, it is necessary to profile quantitatively the expression of multiple subunit mRNAs within individual cells. In this study, single-cell antisense RNA amplification was used to examine the expression of 14 different GABAR subunit mRNAs simultaneously in individual human dentate granule cells (DGCs) harvested during hippocampectomy for intractable epilepsy. α4, β2, and δ-mRNA levels were tightly correlated within individual DGCs, indicating that these subunits are expressed coordinately. Levels of α3- and β2-mRNAs, as well as ε- and β1-mRNAs, also were strongly correlated. No other subunit correlations were identified. Coordinated expression could not be explained by the chromosomal clustering of GABAR genes and was observed in control and epileptic rats as well as in humans, suggesting that it was not species-specific or secondary to epileptogenesis. Benzodiazepine augmentation of GABA-evoked currents also was examined to determine whether levels of subunit mRNA expression correlated with receptor pharmacology. This analysis delineated two distinct cell populations that differed in clonazepam modulation and patterns of α-subunit expression. Clonazepam augmentation correlated positively with the relative expression of α1- and γ2-mRNAs and negatively with α4- and δ-mRNAs. These data demonstrate that specific GABAR subunit mRNAs exhibit coordinated control of expression in individual DGCs, which has significant impact on inhibitory function.