Persistent Traces Research Articles

Blockade of β-Adrenergic Receptors by Propranolol Disrupts Reconsolidation of Drug Memory and Attenuates Heroin Seeking.

Persistent traces of drug reward memories contribute to intense craving and often trigger relapse. A number of pharmacological interventions on drug-associated memories have shown significant benefits in relapse prevention at a preclinical level but their translational potential is limited due to deleterious side effects. Propranolol, a non-specific β-adrenergic receptors antagonist, is known for its ability to erase maladaptive memories associated with nicotine or cocaine in rodents and humans. However, little is known about its effect on reconsolidation of heroin memory and heroin seeking. In the present study, rats with a history of intravenous heroin self-administration received the propranolol treatment (10 mg/kg; i.p.) at different time windows with or without CS (conditioned stimulus) exposure. Our results showed that propranolol, when administered immediately after CS exposure but not 6 h later, can significantly attenuate cue-induced and drug-primed reinstatement of heroin seeking, suggesting that propranolol has the ability to disrupt heroin memory and reduce relapse. The propranolol treatment without retrieval of drug memory had no effect on subsequent reinstatement of heroin seeking, suggesting that its interfering effects are retrieval-dependent. Importantly, the effects of propranolol were long lasting as rats showed diminished drug seeking even 28 days after the treatment. Altogether, our study suggests that propranolol can interfere with reconsolidation of heroin memory and reduce subsequent drug seeking, making it an attractive therapeutic candidate for the treatment of opioid addiction and relapse prevention.

Berberine Facilitates Extinction of Drug-Associated Behavior and Inhibits Reinstatement of Drug Seeking.

A high rate of relapse is a major clinical problem among drug-addicted individuals. Persistent traces of drug-associated reward memories contribute to intense craving and often trigger relapse. A number of interventions on drug-associated memories have shown significant benefits in relapse prevention. Among them are pre- or post-extinction pharmacological manipulations that facilitate the extinction of drug-associated behavior. Berberine, a bioactive isoquinoline alkaloid, has been recently reported to provide therapeutic benefits for a number of central nervous system (CNS) disorders, including morphine addiction. The present study aimed to investigate whether berberine could serve as a post-extinction pharmacological intervention agent to reduce risks of reinstatement of drug seeking. We found that an intragastric administration of berberine at doses of 25 and 50 mg/kg during the critical time window significantly facilitated the extinction of morphine-reward related behavior in free access and confined conditioned place preference (CPP) extinction paradigms, and subsequently, it prevented reinstatement and spontaneous recovery of morphine-induced CPP in mice. Intriguingly, the berberine treatment with or without extinction training altered expression of plasticity-related proteins such as brain-derived neurotrophic factor (BDNF), AMPA receptors (GluA1 and GluA2) in the nucleus accumbens (NAc). Moreover, the post-extinction berberine treatment significantly reduced reinstatement of cocaine-induced CPP and operant intravenous self-administration (IVSA) memories in rats. Altogether, our findings suggest that extinction training combined with the post-extinction berberine treatment can facilitate extinction of drug-associated behavior making it an attractive therapeutic candidate in relapse prevention.

Searching for dark matter with paleo-detectors

A large experimental program is underway to extend the sensitivity of direct detection experiments, searching for interaction of Dark Matter with nuclei, down to the neutrino floor. However, such experiments are becoming increasingly difficult and costly due to the large target masses and exquisite background rejection needed for the necessary improvements in sensitivity. We investigate an alternative approach to the detection of Dark Matter–nucleon interactions: Searching for the persistent traces left by Dark Matter scattering in ancient minerals obtained from much deeper than current underground laboratories. We estimate the sensitivity of paleo-detectors, which extends far beyond current upper limits for a wide range of Dark Matter masses. The sensitivity of our proposal also far exceeds the upper limits set by Snowden-Ifft et al. more than three decades ago using ancient Mica in an approach similar to paleo-detectors.

Symbolic Modeling of Asynchronous Neural Dynamics Reveals Potential Synchronous Roots for the Emergence of Awareness.

A new computational framework implementing asynchronous neural dynamics is used to address the duality between synchronous vs. asynchronous processes, and their possible relation to conscious vs. unconscious behaviors. Extending previous results on modeling the first three levels of animal awareness, this formalism is used here to produce the execution traces of parallel threads that implement these models. Running simulations demonstrate how sensory stimuli associated with a population of excitatory neurons inhibit in turn other neural assemblies i.e., a kind of neuronal asynchronous wiring/unwiring process that is reflected in the progressive trimming of execution traces. Whereas, reactive behaviors relying on configural learning produce vanishing traces, the learning of a rule and its later application produce persistent traces revealing potential synchronous roots of animal awareness. In contrast, to previous formalisms that use analytical and/or statistical methods to search for patterns existing in a brain, this new framework proposes a tool for studying the emergence of brain structures that might be associated with higher level cognitive capabilities.

Microbiota fingerprints lose individually identifying features over time

BackgroundHumans host individually unique skin microbiota, suggesting that microbiota traces transferred from skin to surfaces could serve as forensic markers analogous to fingerprints. While it is known that individuals leave identifiable microbiota traces on surfaces, it is not clear for how long these traces persist. Moreover, as skin and surface microbiota change with time, even persistent traces may lose their forensic potential as they would cease to resemble the microbiota of the person who left them. We followed skin and surface microbiota within households for four seasons to determine whether accurate microbiota-based matching of individuals to their households could be achieved across long time delays.ResultsWhile household surface microbiota traces could be matched to the correct occupant or occupants with 67% accuracy, accuracy decreased substantially when skin and surface samples were collected in different seasons, and particularly when surface samples were collected long after skin samples. Most OTUs persisted on skin or surfaces for less than one season, indicating that OTU loss was the major cause of decreased matching accuracy. OTUs that were more useful for individual identification persisted for less time and were less likely to be deposited from skin to surface, suggesting a trade-off between the longevity and identifying value of microbiota traces.ConclusionsWhile microbiota traces have potential forensic value, unlike fingerprints they are not static and may degrade in a way that preferentially erases features useful in identifying individuals.

Inatualidade e anacronismo na fotografia contemporânea

Resumo O artigo discute as condições de individuação da chamada fotografia contemporânea a partir do exame da noção de anacronismo em diferentes autores e de obras de artistas como Jeff Wall e Cindy Sherman. A construção da discursividade visual na arte como questão de comunicação é formulada através da ideia de que haveria uma inatualidade em certas imagens do presente, percebida pelos traços persistentes de questões e de imagens de outros tempos, particularmente relativos à história da arte. A pertinência de se pensar a experiência do fotográfico na arte reside nas contribuições que esta apresenta para se discutir aspectos propriamente comunicativos da fotografia, particularmente a representação e as operações que nela ordenam o visível e mediam nossas relações com o mundo através da imagem.

Intrinsic Activity of SBA-like Silica in the Catalytic Ozonation of Organic Pollutants

ABSTRACTHydrothermal synthesis using two gel compositions: i. 1 SiO2: 0.059 P123: 56.130 HCl: 607.638 H2O; ii. 1 SiO2: 0.006 P123: 0.013 F127: 42.439 HCl: 442.876 H2O, resulted in highly crystalline SBA-15 and SBA-16 like silica with intrinsic activity in the catalytic ozonation of oxalic acid (OA), phenol (φ-OH) and Orange G (OG) in water at room temperature. X-ray diffraction, nitrogen adsorption–desorption, transmission and scanning electron microscopies revealed highly ordered mesoporous structure, with large surface area, regular channels and uniform particle size. UV-Vis analysis provided faster, more precise and reliable assessments of the decomposition yield and process selectivity than the conventional and laborious method of Chemical Oxygen Demand (COD). The ozone reactivity was found to be favored by increasing size of the organic substrate. OG and phenol decomposition required shorter ozonation time (20, 15 min, respectively) than OA, involving mainly phenyl ring hydroxylation and cleavage. Measurements through thermal programmed desorption of carbon dioxide and water revealed that the catalytic activity of the SBA samples involves adsorption via both acid-base and hydrophobic interactions. Suitable SBA modifications allow tailoring these interactions for even faster ozonation without persistent traces of short chain derivatives.

Palimpsests of Immaterial Assemblages Taken out of Context: Tracing Pompeians from the Void into the Digital

This paper explores some ontological aspects of archaeological voids and enclosures together with their translations and substitutions, and considers the nature of spaces within material archaeological deposits and artefacts. The dematerialized and rematerialized bodies of the victims of Vesuvius in CE 79 are reappraised as a case study. By problematizing the voids we are able to think critically about the ontological status of the victims’ persistent traces and residues. Specifically, using Gavin Lucas’ grid of forces models, we explore how these traces and residues have been transformed into different kinds of objects, including, most recently, rematerializations in the digital, through their ongoing intra-actions within the domains of archaeology, museology, and additive manufacturing. Through this analysis the ambivalent nature of these traces and residues becomes more sensible.

Traces of Defects in the Electronic Structure of Porous Ni–Ti Alloys

The electronic structures of Ni–Ti shape-memory alloy samples were investigated by X-ray absorption fine structure (XAFS) spectroscopy both experimentally and theoretically. In the experimental section, the samples were measured at low temperature to determine the persistent traces of both preheating process and atomic concentration effects on the crystal and electronic structure by X-ray absorption near-edge structure (XANES) spectroscopy. As a second step, the extended-X-ray absorption fine structure (EXAFS) calculations, which are based on different choices of one electron potentials according to Ti coordinations by using the real space multiple scattering method FEFF 8.2 code, were performed. The crystallographic and electronic structures of the porous Ni–Ti alloys were tested at various temperatures ranging from 5 to 1323 K.

TRAGEDY AND THE SEDUCTIONS OF PHILOSOPHY

Since antiquity, Greek tragedy has continually preoccupied philosophers. From Plato and Aristotle, to Hegel and Nietzsche, many of the most interesting ideas in the history of thought have been developed through a dialogue with tragedy. This article explores the continuities and ruptures between Plato and Aristotle's reading of tragedy and the so-called “philosophy of the tragic” which emerged in the late eighteenth century. The influence of this modern tradition has been so profound that, even today, no reading ofAntigone, ofOedipusor of theBacchaeis not also, at least unconsciously, in dialogue with Hegel, with Freud and with Nietzsche. Although there is some recognition that the philosophical understanding of tragedy has historically shaped the discussion of ancient drama, classicists remain resistant to returning to its insights to further the study of classical texts. This article aims to redress the situation not only by revealing the persistent traces of the philosophy of the tragic in our modern critical vocabulary, but also by arguing that a renewed interest in this tradition will invigorate debates within our field. By looking at the examples of the French feminists Hélène Cixous' and Luce Irigaray's interpretations of Sophocles and Aeschylus, the article investigates the apparent tension between historicist and universalising readings of tragedy and argues that these two approaches are not necessarily incompatible.

Modeling Virtual Footprints

Entities interacting on the web establish their identity by creating virtual personas. These entities, or agents, can be human users or software-based. This research models identity using the Entity-Persona Model, a semantically annotated social network inferred from the persistent traces of interaction between personas on the web. A Persona Mapping Algorithm is proposed which compares the local views of personas in their social network referred to as their Virtual Signatures, for structural and semantic similarity. The semantics of the Entity-Persona Model are modeled by a vector space model of the text associated with the personas in the network, which allows comparison of their Virtual Signatures. This enables all the publicly accessible personas of an entity to be identified on the scale of the web. This research enables an agent to identify a single entity using multiple personas on different networks, provided that multiple personas exhibit characteristic behavior. The agent is able to increase the trustworthiness of on-line interactions by establishing the identity of entities operating under multiple personas. Consequently, reputation measures based on on-line interactions with multiple personas can be aggregated and resolved to the true singular identity.

Reading from the outside: The uses of translation for Virginia Woolf's “common reader”

Extending recent critical appraisals of the ways in which Virginia Woolf's politics shape her modernist narrative practices, this essay examines Woolf's non-fiction and its engagement with the political questions surrounding the production, circulation and reception of literature in translation. It proposes that the figure of the “common reader” to whom Woolf addresses many early essays intersects with that of the “Outsider”, whose refusal of national allegiance she identifies as a source of internationally influential political power in Three Guineas. However, the freedom from nationalist cultural authorities that Woolf claims for Outsiders, who necessarily “read and write in their own tongue”, neither guarantees nor even seeks complete intelligibility across cultural borders. Rather, the essays model reading practices that remain attentive to the persistent and productive traces of difference retained in translation and refuse hierarchical divisions between professional and amateur readers within Anglophone communities.

A hardware mechanism for dynamic extraction and relayout of program hot spots

This paper presents a new mechanism for collecting and deploying runtime optimized code. The code-collecting component resides in the instruction retirement stage and lays out hot execution paths to improve instruction fetch rate as well as enable further code optimization. The code deployment component uses an extension to the Branch Target Buffer to migrate execution into the new code without modifying the original code. No significant delay is added to the total execution of the program due to these components. The code collection scheme enables safe runtime optimization along paths that span function boundaries. This technique provides a better platform for runtime optimization than trace caches, because the traces are longer and persist in main memory across context switches. Additionally, these traces are not as susceptible to transient behavior because they are restricted to frequently executed code. Empirical results show that on average this mechanism can achieve better instruction fetch rates using only 12KB of hardware than a trace cache requiring 15KB of hardware, while producing long, persistent traces more suited to optimization.

HLS

As microprocessors continue to evolve, many optimizations reach a point of diminishing returns. We introduce HLS, a hybrid processor simulator which uses statistical models and symbolic execution to evaluate design alternatives. This simulation methodology allows for quick and accurate contour maps to be generated of the performance space spanned by design parameters. We validate the accuracy of HLS through correlation with existing cycle-by-cycle simulation techniques and current generation hardware. We demonstrate the power of HLS by exploring design spaces defined by two parameters: code properties and value prediction. These examples motivate how HLS can be used to set design goals and individual component performance targets. Additionally, these traces are not as susceptible to transient behavior because they are restricted to frequently executed code. Empirical results show that on average this mechanism can achieve better instruction fetch rates using only 12KB of hardware than a trace cache requiring 15KB of hardware, while producing long, persistent traces more suited to optimization.

Mineralogical Characterization of Anode Slimes—I. Anode Copper from Inca's Copper Cliff Copper Refinery

Anode copper from Inco's Copper Cliff Copper Refinery was characterized mineralogically to determine the composition, morphology and relative abundance of the phases present. The anode consists of a copper matrix containing numerous oxide and selenide inclusions, mostly present at the copper gram boundaries but also occurring within individual copper grams. Most of the 0.67% Ni content of he anode is in solid solution in the copper although some is present as tiny NiO crystals Which occur primarily in the upper half of the anode. Virtually all the silver is in solid solution in the copper, and <1% of he total occurs in the inclusion phases. The inclusions present in the anode are mostly Cu2O containing persistent traces of Ni and Se, and NiO containing ∼ 3% Cu in solid solution. The Cu2O occurs as spheroidal or irregular masses ∼10 μm in diameter, whereas the NiO occurs invariably as euhedral crystals <10μm in size. Copper selenide with minor amounts of Te and traces of Pb and Ag is present in complex inclusions with Cu2O, and the selenide is the dominant Te carner. Traces of Pb-Cu-Bi oxide and Pb-Cu oxide were observed in some of the complex inclusions. Many ∼10 μm inclusions of Cu-Ni Silicate and Ca-Cu-Ni silicate also were present, especially in the upper half of the anode. The mineralogical characterization suggests that most of the nickel will dissolve during. copper electrorefining and that the anode slimes will consist predominantly of selenides, NiO, PbSO4, Silicates and possibly stiver telluride.

Recalling oral and written discourse.

We prescribed an expository text in two versions that varied in difficulty. The text was presented either orally or under one of two reading conditions, a normal reading or a moving window condition. The subjects were business trainees whose main communication experience was in either written or spoken communication. Immediately after presentation of the text, we asked the subjects to answer questions about it. The answers given after reading in the moving-window mode were in every respect the same as those given after self-controlled reading. There were differences between the listening condition and the two reading conditions, depending on the nature of the subjects' main communication experience and the difficulty of the text. We concluded from these results that the differences between the processing of oral and written discourse are caused neither by the difference of processing control nor by structural factors but by factors related to the communication experience of the subjects. Recall performance after reading and listening to the same discourse has been shown to be different in terms of the number of text statements recalled accurately (e.g., Green, 1981; Hildyard & Olson, 1982; Hron, Kurbjuhn, Mahdi, & Schnotz, 1985; Rickheit & Strohner, 1983). In these studies, reading resulted in more accurate free recall than did listening. Reading seems to be particularly advantageous in recalling difficult texts (e.g., Hildyard & Olson, 1978; Miisseler, Rickheit, & Strohner, 1985). But there are also results that show a better free recall after listening than after reading (Sannomiya, 1982, 1984; Thorndyke, 1976). This may be due to the ways the tasks were presented in these studies. For example, Thorndyke presented his visual text in lines. This procedure may have disrupted some units of meaning and thus prevented the text from being encoded as semantic units. The studies of Sannomiya (1982, 1984) show that omitting data at the level of micropropositions and recruiting as subjects pupils with insufficient reading ability could lead to a misinterpretation of the results. In the present study we attempted to clarify the modality effect and to establish the kind of mechanisms involved. There seem to be two plausible explanations for the modality effect: a structural advantage and a processing advantage of the visual modality. Proponents of the structural explanation claim, for example, that some inherent qualities of the visual modality, such as its neurological basis, result in more persistent traces than