3,854 research outputs found

    Finite Size Effect in Persistence

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    We have investigated the random walk problem in a finite system and studied the crossover induced in the the persistence probability scales by the system size.Analytical and numerical work show that the scaling function is an exponentially decaying function.The particle here is trapped with in a box of size LL . We have also considered the problem when the particle in trapped in a potential. Direct calculation and numerical result show that the scaling function here also an exponentially decaying function. We also present numerical works on harmonically trapped randomly accelerated particle and randomly accelerated particle with viscous drag.Comment: revtex4, 4 pages, 4 figure

    Characterization of vertical electric fields and associated voltages induced on a overhead power line from close artificially initiated lightning

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    Measurements were characterized of simultaneous vertical electric fields and voltages induced at both ends of a 448 m overhead power line by artificially initiated lightning return strokes. The lightning discharges struck ground about 20 m from one end of the line. The measured line voltages could be grouped into two categories: those in which multiple, similarly shaped, evenly spaced pulses were observed, which are called oscillatory; and those dominated by a principal pulse with subsidiary oscillations of much smaller amplitude, which are called impulsive. Voltage amplitudes range from tens of kilovolts for oscillatory voltages to hundreds of kilovolts for impulsive voltages

    Yanagita Kunio and the culture film: discovering everydayness and creating/imagining a national community, 1935–1945

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    In wartime Japan, folklore studies (minzokugaku) as an academic discipline emerged at the same time as the rise of the culture film (bunka eiga). Both helped mobilize peripheral areas and firmly created the image of a unitary nation. This paper focuses on Living by the Earth (Tsuchi ni ikiru, 1941), directed by Miki Shigeru, and its spinoff photo album titled People of the Snow Country (Yukiguni no minzoku, 1944). Miki filmed rural life and ordinary people in the Tohoku region under the strong influence of Yanagita Kunio, a founder of Japanese folklore studies, and published the photo album in collaboration with Yanagita. In this project, vanishing customs were paradoxically regarded as objects impossible to photograph. However, that paradox enhanced the value of the project and made it easier to construct an imagined national community through the discourse of folklore studies

    A new Eumerus hoverfly (Diptera: Syrphidae) from Namibia and South Africa, with notes on similar species

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    Within the pollinator family Syrphidae, Eumerus Meigen, 1822 is a diverse genus with over 70 species recorded in the Afrotropical Region. A new species is described here from Namibia and South Africa. Adults are small to medium size flies, with spur-like expansions in the metatarsomeres 2 and 3. DNA sequences of the Cytochrome c oxidase subunit I (COI) gene were obtained from Namibian specimens. This is only the second Eumerus species documented from Namibia, where it was recorded from The National Botanic Garden, Windhoek. The new species is compared with similar species such as Eumerus vestitus Bezzi, 1912, for which a lectotype is designated. In addition, a new and preliminary morphological concept of the Eumerus obliquus group is proposed and a key to its African species is provided.Antonio Ricarte’s position (Ref. UATAL05) at the University of Alicante is funded by the ‘Vicerrectorado de Investigación y Transferencia de Conocimiento’. This study belongs to Project PGC2018-095851-A-C65 of the Spanish Ministry of Science, Innovation and Universities

    What do Eumerus Meigen larvae feed on? New immature stages of three species (Diptera: Syrphidae) breeding in different plants

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    The genus Eumerus Meigen 1822 (Diptera: Syrphidae) is widely distributed in the Old World, though recently introduced into America, and their larvae feed on decaying vegetal material and/or inside underground storage organs of many plants, sometimes generating economic losses as pests. However, little is known about Eumerus larval cycles and their interactions with host plants. Here, immatures of three Eumerus species from different continents are described, noting their feeding habits and host plants. Larvae of Eumerus figurans Walker 1859 were obtained from Hawaiian cultured ginger roots; puparium of Eumerus alpinus Rondani 1857 originated from larvae collected in Asphodelus ramosus L. in France; puparia of Eumerus superbus Shannon 1927 were reared from larvae found in two Zamiaceae species from Australia. Mitochondrial COI sequences served for diagnosing E. figurans larvae. Optical and scanning electron microscopy were used to describe body features, head skeletons, anterior spiracles, pupal spiracles, and posterior respiratory processes. Overall, E. alpinus resembles E. nudus Loew 1848 immatures. Eumerus superbus has a remarkable morphology among all described immatures of the genus, being the only Eumerus reported from gymnosperms. Head skeleton of E. figurans suggests this species is a filtering one. Present findings show that larvae of Eumerus can be separated at the species level and that this genus is polyphagous, feeding on a wide range of plant tissues and taxa, including commercial species. This study emphasizes immature stages and breeding sites as important means to understand species life cycles and the interactions with their host plants and ecosystems.This study is part of Gabriel J. Souba-Dols’ PhD thesis. His position at the University of Alicante (FPU-UA 2016), as well as that of Antonio Ricarte (Ref. UATAL05), are funded by the “Vicerrectorado de Investigación y Transferencia del Conocimiento.” Additionally, this research was partly funded by the Project PGC2018-095851-A-C65 of the Spanish Ministry of Science, Innovation and Universities

    PI3Kα inhibition reduces obesity in mice

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    Partial inhibition of PI3K is one of the best-validated and evolutionary conserved manipulations to extend longevity. The best known health beneficial effects of reduced PI3K are related to metabolism and include increased energy expenditure, reduced nutrient storage, and protection from obesity. We have previously shown that a dual chemical inhibitor of the alpha and delta PI3K isoforms (CNIO-PI3Ki) reduces obesity in mice and monkeys, without evident toxic effects after long-term treatment. Here, we dissect the role of the alpha and delta PI3K isoforms by making use of selective inhibitors against PI3Kα (BYL-719 also known as alpelisib) or PI3Kδ (GS-9820 also known as acalisib). Treatment of mice with the above mentioned inhibitors indicated that BYL-719 increases energy expenditure in normal mice and efficiently reduces body weight in obese (ob/ob) mice, whereas these effects were not observed with GS-9820. Of note, the dose of BYL-719 required to reduce obesity was 10x higher than the equivalent dose of CNIO-PI3Ki, which could suggest that simultaneous inhibition of PI3K alpha and delta is more beneficial than single inhibition of the alpha isoform. In summary, we conclude that inhibition of PI3Kα is sufficient to increase energy expenditure and reduce obesity, and suggest that concomitant PI3Kα inhibition could play an auxiliary role

    A Gene Encoding Arginyl-tRNA Synthetase Is Located in the Upstream Region of the lysA Gene in Brevibacterium lactofermentum: Regulation of argS-lysA Cluster Expression by Arginine

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    International audienceThe Brevibacterium lactofermentum argS gene, which encodes an arginyl-tRNA synthetase, was identified in the upstream region of the lysA gene. The cloned gene was sequenced; it encodes a 550-amino-acid protein with an Mr of 59,797. The deduced amino acid sequence showed 28% identical and 49% similar residues when compared with the sequence of the Escherichia coli arginyl-tRNA synthetase. The B. lactofermentum enzyme showed the highly conserved motifs of class I aminoacyl-tRNA synthetases. Expression of the argS gene in B. lactofermentum and E. coli resulted in an increase in aminoacyl-tRNA synthetase activity, correlated with the presence in sodium dodecyl sulfate-polyacrylamide gels of a clear protein band that corresponds to this enzyme. One single transcript of about 3,000 nucleotides and corresponding to the B. lactofermentum argS-lysA operon was identified. The transcription of these genes is repressed by lysine and induced by arginine, showing an interesting pattern of biosynthetic interlock between the pathways of both amino acids in corynebacteria

    Social comparison processes and catastrophising in fibromyalgia:A path analysis

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    Introduction: In addition to coping strategies, social comparison may play a role in illness adjustment. However, little is known about the role of contrast and identification in social comparison in adaptation to fibromyalgia.Aim: To evaluate through a path analysis in a sample of fibromyalgia patients, the association between identification and contrast in social comparison, catastrophising and specific health outcomes (fibromyalgia illness impact and psychological distress).Material and Method: 131 Spanish fibromyalgia outpatients (mean age: 50.15, SD=11.1) filled out a questionnaire.Results: We present a model that explained 33% of the variance in catastrophising by direct effects of more use of upward contrast and downward identification. In addition, 35% of fibromyalgia illness impact variance was explained by less upward identification, more upward contrast and more catastrophising and 42% of the variance in psychological distress by a direct effect of more use of upward contrast together with higher fibromyalgia illness impact.Discussion: We suggest that intervention programmes with chronic pain and fibromyalgia patients should focus on enhancing the use of upward identification in social comparison, and on minimising the use of upward contrast and downward identification in social comparison

    Tracing tendencies in the Japanese documentary mode

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    The documentary mode has not had the recognition it deserves in the western historiography of Japanese cinema. The ‘discovery’ of that cinema at film festivals in Europe and the United States in the 1950s, and the growth of academic and popular writing that followed, prioritized aesthetic and cultural difference and obscured Japan’s contribution to the documentary mode. Canonical authors such as Donald Richie, who was instrumental in introducing Japanese cinema to the West, even claimed that Japan did not have a true documentary tradition due to the apparent preference of the Japanese audience for stylisation over realism, a preference that originated from its theatrical tradition (Richie 1990, p. 60). And yet, over 130,000 documentary films were made between 1945 and 2010 (Murayama 2010, pp. 240–46), and postwar Japanese documentary films regularly won prizes at specialist film festivals.1 Beyond documentary film production itself, a closer look at the history of Japanese feature film production also calls Richie’s assertion into question. “Semi-documentary” and “documentary touch” were clichés of postwar feature film criticism, in response to a renewed emphasis on actuality and ordinary life in at least one strand of Japanese studio and independent production. This special issue, Developments in Japanese Documentary Mode, seeks to challenge the predominance of fiction film in the literature on Japanese cinema, and in particular the assumption of a stylised Japanese aesthetic. It reveals a broad sense in Japan of the film medium as connected to material and phenomenological authenticity, even as that rhetorical effect was sometimes put in service to political and economic ideologies

    Cold-spray of aluminium with and without ceramic combined with plasma electrolytic oxidation

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    Cold spraying is developing rapidly and has a wide spectrum of applications: protection against corrosion, preparation of high conductivity coatings, repair of damaged metal components, metal additive manufacturing, thermal management. Plasma electrolytic oxidation (PEO) is widely used to improve the corrosion and wear resistance of lightweight metals such as aluminum alloys by the formation of a ceramic oxide layer. When applied on aluminium alloys, the PEO oxide layer is mainly composed with γ-Al2O3 (in major proportion) and corundum, α-Al2O3. Increasing the proportion of corundum is an objective in order to improve the corrosion and wear resistance properties. For this purpose, a duplex treatment combining cold spray and PEO is investigate [1]. Particularly it consists in firstly cold spraying an aluminium coating containing a certain amount of α-Al2O3 which is then PEO processed. Our results show that, while the projected alpha alumina particles are observable on cross sections of untreated samples and for short PEO treatment times (lower than 20 min), this is no longer the case for long PEO treatment times (over than 35 min) (see the figure). In fact, under these conditions, it is no longer possible to observe the alpha alumina particles in the PEO layer. More interesting still, the proportion of alpha alumina in the layers resulting from a duplex treatment is greater than that obtained in the layer resulting from a cold spray treatment by scanning electron microscope
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