6,275 research outputs found

    The mean magnetic field of the sun: Observations at Stanford

    Get PDF
    A solar telescope was built at Stanford University to study the organization and evolution of large-scale solar magnetic fields and velocities. The observations are made using a Babcock-type magnetograph which is connected to a 22.9 m vertical Littrow spectrograph. Sun-as-a-star integrated light measurements of the mean solar magnetic field were made daily since May 1975. The typical mean field magnitude is about 0.15 gauss with typical measurement error less than 0.05 gauss. The mean field polarity pattern is essentially identical to the interplanetary magnetic field sector structure (seen near the earth with a 4 day lag). The differences in the observed structures can be understood in terms of a warped current sheet model

    Automatic Monitoring of dairy cows’ lying behaviour using a computer vision system in open barns

    Get PDF
    Received: January 31st, 2023 ; Accepted: April 9th, 2023 ; Published: April 27th, 2023 ; Correspondence: [email protected] Livestock Farming offers opportunities for automated, continuous monitoring of animals, their productivity, welfare and health. The video-based assessment of animal behaviour is an automated, non-invasive and promising application. The aim of this study is to identify possible parameters in dairy cows’ lying behaviour that are the basis for a holistic computer vision-based system to assess animal health and welfare. Based on expert interviews and a literature review, we define parameters and their optimum in form of gold standards to evaluate lying behaviour automatically. These include quantitative parameters such as daily lying time, lying period length, lying period frequency and qualitative parameters such as extension of the front and hind legs, standing in the lying cubicles, or total lateral position. The lying behaviour is an example within the research context for the development of a computer vision-based tool for automated detection of animal behaviour and appropriate housing design

    Expression of the Antisense-to-Latency Transcript Long Noncoding RNA in Kaposi's Sarcoma-Associated Herpesvirus

    Get PDF
    ABSTRACT The regulation of latency is central to herpesvirus biology. Recent transcriptome-wide surveys have uncovered evidence for promiscuous transcription across the entirety of the Kaposi's sarcoma-associated herpesvirus (KSHV) genome and postulated the existence of multiple viral long noncoding RNAs (lncRNAs). Next-generation sequencing studies are highly dependent on the specific experimental approach and particular algorithms of analysis and therefore benefit from independent confirmation of the results. The antisense-to-latency transcript (ALT) lncRNA was discovered by genome-tiling microarray (Chandriani et al., J Virol 86:7934–7942, 2010, https://doi.org/10.1128/JVI.00645-10 ). To characterize ALT in detail, we physically isolated this lncRNA by a strand-specific hybrid capture assay and then employed transcriptome sequencing and novel reverse transcription-PCR (RT-PCR) assays to distinguish all RNA species in the KSHV latency region. These methods confirm that ALT initiates at positions 120739/121012 and encodes a single splice site, which is shared with the 3′-coterminal K14-vGPCR/ORF74 mRNA, terminating at 130873 (GenBank accession number GQ994935 ), resulting in an ∼10,000-nucleotide transcript. No shorter ALT isoforms were identified. This study also identified a novel intron within the LANA 5′ untranslated region using a splice acceptor at 127888. In summary, ALT joins PAN/nut1/T1.1 as a bona fide lncRNA of KSHV with potentially important roles in viral gene regulation and pathogenesis. IMPORTANCE Increasing data support the importance of noncoding RNAs (ncRNAs), including microRNAs (miRNAs) and lncRNAs, which have been shown to exert critical regulatory functions without coding for recognizable proteins. Defining the sequences of these ncRNAs is essential for future studies aiming to functionally characterize a specific ncRNA. Most lncRNA studies are highly dependent on high-throughput sequencing and bioinformatic analyses, few studies follow up on the initial predictions, and analyses are at times discordant. The manuscript characterizes one key viral lncRNA, ALT, by physically isolating ALT and by a sequencing-independent assay. It provides for a simple assay to monitor lncRNA expression in experimental and clinical samples. ALT is expressed antisense to the major viral latency transcripts encoding LANA as well as the viral miRNAs and thus has the potential to regulate this key part of the viral life cycle

    Playing with the future: social irrealism and the politics of aesthetics

    Get PDF
    In this paper we wish to explore the political possibilities of video games. Numerous scholars now take seriously the place of popular culture in the remaking of our geographies, but video games still lag behind. For us, this tendency reflects a general response to them as imaginary spaces that are separate from everyday life and 'real' politics. It is this disconnect between abstraction and lived experience that we complicate by defining play as an event of what Brian Massumi calls lived abstraction. We wish to short-circuit the barriers that prevent the aesthetic resonating with the political and argue that through their enactment, video games can animate fantastical futures that require the player to make, and reflect upon, profound ethical decisions that can be antagonistic to prevailing political imaginations. We refer to this as social irrealism to demonstrate that reality can be understood through the impossible and the imagined

    Bipyridinium-bis(carboxylate) Radical Based Materials: X-ray, EPR and Paramagnetic Solid-State NMR Investigations

    Get PDF
    The zwitterionic 1,1′-bis(4-carboxyphenyl)-4,4′-bipyridinium (bp4pc) has been synthesized and crystals of its hydrated form bp4pc·2H2O and of its protonated reduced form H-bp4pc have been obtained. Upon heating, bp4pc·2H2O undergoes partial dehydration, leading to bp4pc·H2O at 160 °C, together with a color change from yellow (room temperature) to green (140 °C) and finally to brown (160–180 °C). Analysis of bond lengths in the solid state reveals the expected short (d = 1.425 Å) and long (d = 1.485 Å) C–C central bond lengths in the all-radical salt H-bp4pc and bp4pc·2H2O, respectively, whereas the distance of 1.475 Å in bp4pc·H2O does not allow a conclusion to be drawn regarding the presence of radicals in this compound. EPR and solid-state paramagnetic NMR experiments of H-bp4pc and the hydrated zwitterion bp4pc·2H2O at different temperatures, however, show that the color change of the latter upon heating is due to the presence of bipyridinium radicals, the concentration of which, although low, increases with increasing temperature. The nature of the electron donor involved in this thermal-induced electron transfer is not fully understood. Most plausible is the possibility that it is the carboxylate group with an intramolecular electron-transfer process; on the other hand it, cannot be excluded that the electron stems from the water molecule, which decomposes into O2, H+, and e– giving H-bp4pc entities
    • …
    corecore