6,517 research outputs found
A rational approach to Pi, Notes of a lecture held on the occasion of Pi-day on July 5, 2000 in Leiden
No full textThis article is based on notes for the lecture with the same title, which was held by the author on the occasion of the `Pi in de Pieterskerk' event (Pi-day) on July 5, 2000. The present article expands these notes with short proofs of most of the theorems given, but not proved, during the lecture
Phenibut (4-amino-3-phenyl-butyric acid): Availability, prevalence of use, desired effects and acute toxicity.
No full textINTRODUCTION AND AIMS: There has been a global increase in the availability and use of novel psychoactive substances (NPS) over the last decade. Phenibut (β-phenyl-γ-aminobutyric acid) is a GABAB agonist that is used as an NPS. Here, we bring together published scientific and grey information sources to further understand the prevalence of use, desired effects and acute toxicity of phenibut. DESIGN AND METHODS: Using European Monitoring Centre for Drugs and Drug Addiction Internet snapshot methodology, we undertook an English language Internet snapshot survey in May 2015 to gather information on the availability and price of phenibut from Internet NPS retailers. To gather information on prevalence of use, desired effects and/or adverse effects, we searched grey literature (online drug discussion forums) and medical literature (PubMed and abstracts from selected International Toxicology conferences). RESULTS: We found 48 unrelated Internet suppliers selling phenibut in amounts ranging from 5 g (US0.23, £0.14/g). Capsules containing 200-500 mg of phenibut were available in packs of between 6 (US0.43, £0.27/g). According to the grey literature, phenibut is taken for its anxiolytic and euphoric properties, with tolerance and withdrawal syndromes commonly reported adverse effects. Phenibut is taken orally at an average dose of 2.4 g. Case reports in the medical literature feature users who present to emergency departments heavily sedated or experiencing withdrawal. There have been no reported deaths relating to phenibut use. DISCUSSION AND CONCLUSIONS: Phenibut is readily available in the UK from Internet sites selling NPS. Its desired and adverse effects appear similar to other gamma-aminobutyric acid receptor agonists. [Owen DR, Wood DM, Archer JRH, Dargan PI. Phenibut (4-amino-3-phenyl-butyric acid): Availability, prevalence of use, desired effects and acute toxicity. Drug Alcohol Rev 2015;00:000-000]
"I' ll tell you a story that will make you believe" in narratives: the role of metafiction in the novel and in the film Life of Pi
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão, Programa de Pós-Graduação em Inglês: Estudos Linguísticos e Literários, Florianópolis, 2015.Recentes estudos propõem que adaptações cinematográficas sejam entendidas como fonte de criação, os quais refletem contextos e interpretações diferentes do texto em que são baseadas. Nessa dissertação, propõe-se uma análise comparativa do romance Life of Pi (2001), de Yann Martel e do filme homônimo dirigido por Ang Lee (2012). A análise tem como objetivo identificar a presença e o modo em que a metaficção é construída no romance e no filme, e quais são alguns significados produzidos por ela em ambos os textos, tanto o literário quanto o fílmico. A concepção de metafição se baseia nas definições de Linda Hutcheon e Patricia Waugh. Por metaficção, entende-se a ficção consciente de si, que expõe o processo de escrita ao leitor e o convida a ter um papel ativo na construção do significado. Após uma análise comparativa dos dois textos, conclui-se que a metaficção está presente em ambos, tanto tematicamente como estruturalmente. As reflexões sobre narrativas apresentadas pelos personagens, o uso de vários níveis narrativos e de intertextualidade revelam diferentes usos da metafição em ambos. A diferença mais importante entre o romance e o filme Life of Pi está no uso dos níveis narrativos. Enquanto o romance possui um ?autor? sem nome que apresenta a história aos leitores, o filme possui um diretor implícito que deixa pistas de qual versão da história de Pi é ?real? no contexto da narrativa. Essa diferença dá ao romance um final aberto, em que o leitor deve escolher qual versão da história ele acredita, enquanto o filme possui uma resolução para essa questão. O filme, então, pode ser entendido como um testemunho, uma narrativa de trauma de um sobrevivente de um naufrágio e da experiência de migração, enquanto o livro não apresenta uma decisão em relação às versões da história, deixando o leitor aberto a qualquer possibilidade.Abstract : Recent studies propose that Film Adaptations should be understood as sources of creation, which also reflect a different context and interpretation from the text upon which they were based. In this thesis, I propose a comparative analysis of the novel Life of Pi (2001), by Yann Martel, and the homonymous film directed by Ang Lee (2012). The analysis has the objective of identifying the presence and the way in which metafiction is constructed in the novel and in the film, and what are some of the meanings produced by it in both texts, the filmic and the literary. The concept of metafiction was based on the definitions by Linda Hutcheon and Patricia Waugh. It is understood as the self-conscious fictional text, which exposes the writing process to the readers and invites them to have an active role in the construction of meaning. In the comparative analyses of the two texts, I have proved that metafiction is present in the two texts, both thematically and structurally. The reflections of the characters on narrative itself as well as the use of different narrative levels and intertextual references reveal different uses of metanarrative in both film and novel. The most important difference between the novel and the film Life of Pi is in their uses of different narrative levels. While the novel has an unnamed =author? who presents the story to the readers, the film has an implicit director who leaves =clues? of which version of Pi?s story is ?real? in the context of the narrative. This difference gives to the novel an open end, facein which the readers must choose which version of the story they believe in, while the film presents a resolution to this question. The film, thus, can be understood as a testimony narrative, a narrative of the trauma of a survivor from a shipwreck and from the experience of migration, while the novel does not decide for one of the versions of the story, enabling a more inconclusive reading
Tangle-bearing neurons survive despite disruption of membrane integrity in a mouse model of tauopathy
No full textNeurofibrillary tangles (NFTs) are associated with neuronal loss and correlate with cognitive impairment in Alzheimer disease, but how NFTs relate to neuronal death is not clear. We studied cell death in Tg4510 mice that reversibly express P301L mutant human tau and accumulate NFTs using in vivo multiphoton imaging of neurofibrillary pathology, propidium iodide (PI) incorporation into cells, caspase activation, and DNA labeling. We first observed that in live mice, a minority of neurons were labeled with the caspase probe or with PI fluorescence. These markers of cell stress were localized in the same cells and appeared specifically within NFT-bearing neurons. Contrary to expectations, the PI-stained neurons did not die during a day of observation; the presence of Hoechst-positive nuclei in them on the subsequent day indicated that the NFT-associated membrane disruption, as suggested by PI staining, and caspase activation do not lead to immediate death of neurons in this tauopathy model. This unique combination of in vivo multiphoton imaging with markers of cell death and pathological alteration is a powerful tool for investigating neuronal damage associated with neurofibrillary pathology
Amplitude analysis of D-0 -> K- pi(+) pi(+) pi(-)
No full textKolcu, Onur Buğra (Arel Author)Kolcu, Onur Buğra (Arel Author)We present an amplitude analysis of the decay D-0 -> K- pi(+)pi(+)pi(-) based on a data sample of 2.93 fb(-1) acquired by the BESIII detector at the psi(3770) resonance. With a nearly background free sample of about 16000 events, we investigate the substructure of the decay and determine the relative fractions and the phases among the different intermediate processes. Our amplitude model includes the two-body decays D-0 -> (K) over bar*(0)rho(0), D-0 -> K- a(1)(+) (1260) and D-0 -> K-1(-)(1270)pi(+), the three-body decays D-0 -> K-1(-)*(0)pi(+)pi(-) and D-0 -> K- pi(+)rho(0), as well as the four-body nonresonant decay D-0 -> K- pi(+)pi(+)pi(-). The dominant intermediate process is D-0 -> K(-)a(1)(+)(1260)accounting for a fit fraction of 54.6%.We present an amplitude analysis of the decay D-0 -> K- pi(+)pi(+)pi(-) based on a data sample of 2.93 fb(-1) acquired by the BESIII detector at the psi(3770) resonance. With a nearly background free sample of about 16000 events, we investigate the substructure of the decay and determine the relative fractions and the phases among the different intermediate processes. Our amplitude model includes the two-body decays D-0 -> (K) over bar*(0)rho(0), D-0 -> K- a(1)(+) (1260) and D-0 -> K-1(-)(1270)pi(+), the three-body decays D-0 -> K-1(-)*(0)pi(+)pi(-) and D-0 -> K- pi(+)rho(0), as well as the four-body nonresonant decay D-0 -> K- pi(+)pi(+)pi(-). The dominant intermediate process is D-0 -> K(-)a(1)(+)(1260)accounting for a fit fraction of 54.6%
Measurement of singly Cabibbo-suppressed decays D-0 -> pi(0)pi(0)pi(0), pi(0)pi(0)eta, pi(0)eta eta and eta eta eta
No full textKolcu, Onur Buğra (Arel Author)Using a data sample of e(+)e(-) collision data corresponding to an integrated luminosity of 2.93 fb(-1) collected with the BESIII detector at a center-of-mass energy of root s = 3.773 GeV, we search for the singly Cabibbo-suppressed decays D-0 -> pi(0)pi(0)pi(0), pi(0)pi(0)eta, pi(0)eta eta and eta eta eta using the double tag method. The absolute branching fractions are measured to be B(D-0 -> pi(0)pi(0)pi(0)) = (2.0 +/- 0.4 +/- 0.3) x 10(-4), B(D-0 -> pi(0)pi(0)eta) = (3.8 +/- 1.1 +/- 0.7) x 10(-4) and B(D-0 -> pi(0)eta eta) = (7.3 +/- 1.6 +/- 1.5) x 10(-4) with the statistical significances of 4.8 sigma, 3.8 sigma and 5.5 sigma, respectively, where the first uncertainties are statistical and the second ones systematic. No significant signal of D-0 -> eta eta eta is found, and the upper limit on its decay branching fraction is set to be B(D-0 -> eta eta eta) < 1.3 x 10(-4) at the 90% confidence level. (C) 2018 The Author(s). Published by Elsevier B.V
Amplitude Analysis of the Decays eta ' -> pi(+)pi(-)pi(0) and eta' -> pi(0)pi(0)pi(0)
No full textKolcu, Onur Buğra (Arel Author)Based on a sample of 1.31 x 10(9) J/Psi events collected with the BESIII detector, an amplitude analysis of the isospin-violating decays eta' -> pi(+)pi(-)pi(0) and eta' -> pi(0)pi(0)pi(0) is performed. A significant P-wave contribution from eta' -> rho(+/-)eta(-/+) is observed for the first time in eta' -> pi(+)pi(-)pi(0). The branching fraction is determined to be B(eta' -> rho(+/-)pi(-/+)) = (7.44 +/- 0.60 +/- 1.26 +/- 1.84) x 10(-4), where the first uncertainty is statistical, the second systematic, and the third model dependent. In addition to the nonresonant S-wave component, there is a significant sigma meson component. The branching fractions of the combined S-wave components are determined to be B(eta' -> pi(+)pi(-)pi(0))(S) = (37.63 +/- 0.77 +/- 2.22 +/- 4.48) x 10(-4) and B(eta' -> pi(0)pi(0)pi(0)) = (35.22 +/- 0.82 +/- 2.54) x 10(-4), respectively. The latter one is consistent with previous BESIII measurements
Josephson junction dynamics in the presence of - and -periodic supercurrents
No full text10 pages, 9 figures; comments are welcomeInternational audienceWe investigate theoretically the dynamics of a Josephson junction in the framework of the RSJ model. We consider a junction that hosts two supercurrrent contributions: a - and a -periodic in phase, with intensities and respectively. We study the size of the Shapiro steps as a function of the ratio of the intensity of the mentioned contributions, i.e. . We provide detailed explanations where to expect clear signatures of the presence of the -periodic contribution as a function of the external parameters: the intensity AC-bias and frequency . On the one hand, in the low AC-intensity regime (where is much smaller than the critical current, ), we find that the non-linear dynamics of the junction allows the observation of only even Shapiro steps even in the unfavorable situation where . On the other hand, in the opposite limit (), even and odd Shapiro steps are present. Nevertheless, even in this regime, we find signatures of the -supercurrent in the beating pattern of the even step sizes as a function of
Observation of the decay Lambda(+)(c) -> Sigma(-)pi(+)pi(+)pi(0)
No full textKolcu, Onur Buğra (Arel Author)We report the first observation of the decay Lambda(+)(c) -> Sigma(-)pi(+)pi(+)pi(0), based on data obtained in e(+)e(-) annihilations with an integrated luminosity of 567 pb(-1) at vs = 4.6 GeV. The data were collected with the BESIII detector at the BEPCII storage rings. The absolute branching fraction B(Lambda(+)(c) -> Sigma(-)pi(+)pi(+)pi(0)) is determined to be (2.11 +/- 0.33(stat.) +/- 0.14(syst.))%. In addition, an improved measurement of B(Lambda(+)(c) -> Sigma(-)pi(+)pi(+)pi(0)) is determined as (1.81 +/- 0.17(stat.) +/- 0.09(syst.))%
Use of Raspberry Pi in the home
No full textThis work is devoted to description of Raspberry Pi computers, their commissioning and verification of their functionality by the author. The first part deals with the basic introduction of Raspberry Pi single-board computers, the Raspberry Pi Foundation and a short history of computer development. Three competing products of the present time are also described. In the practical part, the author describes how to get the Raspberry Pi computer to work for common computer users using the Raspbian operating system and memory card and everything is validated by the author. In the last phase of the work, the use of Raspberry Pi is described for household monitoring and for monitoring of various variables. The author of this work verifies that by connecting a Raspberry Pi camera module or various sensors such as temperature sensor or motion detection sensor. There will be briefly described other possibilities of using Raspberry Pi computers at the end of the thesis
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