393 research outputs found

    Ranking the importance of nuclear reactions for activation and transmutation events

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    Pathways-reduced analysis is one of the techniques used by the Fispact-II nuclear activation and transmutation software to study the sensitivity of the computed inventories to uncertainties in reaction cross-sections. Although deciding which pathways are most important is very helpful in for example determining which nuclear data would benefit from further refinement, pathways-reduced analysis need not necessarily define the most critical reaction, since one reaction may contribute to several different pathways. This work examines three different techniques for ranking reactions in their order of importance in determining the final inventory, comparing the pathways based metric (PBM), the direct method and one based on the Pearson correlation coefficient. Reasons why the PBM is to be preferred are presented.Comment: 30 pages, 10 figure

    Uji Toksisitas Dengan Metode BSLT Dan Analisis Kandungan Fitokimia Ekstrak Daun Soyogik (Saurauia Bracteosa DC) Dengan Metode Soxhletasi

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    Penelitian ini bertujuan untuk mengetahui toksisitas dari ekstrak daun soyogik menggunakan metode Brine Shrimp Lethality Test (BSLT) dan menentukan kandungan fitokimia daun soyogik (Saurauia bracteosa DC). Ekstrak dibuat dengan cara soxhletasi menggunakan pelarut metanol. Uji toksisitas dilakukan dengan menggunakan larva udang Artemia salina Leach yang berumur 48 jam. Efek toksik ekstrak diidentifikasi dengan presentase kematian larva udang menggunakan analisis probit (LC50). Kandungan fitokimia meliputi fenolik, flavonoid dan tanin. Penelitian menunjukkan ekstrak daun soyogik bersifat toksik (LC50: 35,4 ppm). Kandungan senyawa fenolik (128 ppm), flavonoid (44,4 ppm), tanin (86,75 ppm).The aims of this research were to determine the toxicity of soyogik (Saurauia bracteosa DC)leaf extract using Brine Shrimp Lethality Test (BSLT) and the content of its compounds. The extraction was carried out ​​by soxhletation using methanol. Toxicity assay used Artemia salina Leach larvae of 48-hours age. Toxic effects of the extract were identified by the percentage mortality of shrimp larvae using probit analysis (LC50). Leaf extract was furthertested to phenolic, flavonoid and tannin contents. The results showed soyogik leaf extract was toxic (LC50: 35,4 ppm). The content of phenolic, flavonoid, and tannin compounds were 128 ppm, 44,4 ppm and 86,75 ppm, respectively

    OT 060420: A Seemingly Optical Transient Recorded by All-Sky Cameras

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    We report on a ~5th magnitude flash detected for approximately 10 minutes by two CONCAM all-sky cameras located in Cerro Pachon - Chile and La Palma - Spain. A third all-sky camera, located in Cerro Paranal - Chile did not detect the flash, and therefore the authors of this paper suggest that the flash was a series of cosmic-ray hits, meteors, or satellite glints. Another proposed hypothesis is that the flash was an astronomical transient with variable luminosity. In this paper we discuss bright optical transient detection using fish-eye all-sky monitors, analyze the apparently false-positive optical transient, and propose possible causes to false optical transient detection in all-sky cameras.Comment: 7 figures, 3 tables, accepted PAS

    van der Waals density functionals built upon the electron-gas tradition: Facing the challenge of competing interactions

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    The theoretical description of sparse matter attracts much interest, in particular for those ground-state properties that can be described by density functional theory (DFT). One proposed approach, the van der Waals density functional (vdW-DF) method, rests on strong physical foundations and offers simple yet accurate and robust functionals. A very recent functional within this method called vdW-DF-cx [K. Berland and P. Hyldgaard, Phys. Rev. B 89, 035412] stands out in its attempt to use an exchange energy derived from the same plasmon-based theory from which the nonlocal correlation energy was derived. Encouraged by its good performance for solids, layered materials, and aromatic molecules, we apply it to several systems that are characterized by competing interactions. These include the ferroelectric response in PbTiO3_3, the adsorption of small molecules within metal-organic frameworks (MOFs), the graphite/diamond phase transition, and the adsorption of an aromatic-molecule on the Ag(111) surface. Our results indicate that vdW-DF-cx is overall well suited to tackle these challenging systems. In addition to being a competitive density functional for sparse matter, the vdW-DF-cx construction presents a more robust general purpose functional that could be applied to a range of materials problems with a variety of competing interactions

    'This is what democracy looks like' : New Labour's blind spot and peripheral vision

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    New Labour in government since 1997 has been roundly criticized for not possessing a clear, coherent and consistent democratic vision. The absence of such a grand vision has resulted, from this critical perspective, in an absence of 'joined-up' thinking about democracy in an evolving multi-level state. Tensions have been all too apparent between the government's desire to exert central direction - manifested in its most pathological form as 'control freakery' - and its democratising initiatives derived from 'third-way' obsessions with 'decentralising', 'empowering' and 'enabling'. The purpose of this article is to examine why New Labour displayed such apparently impaired democratic vision and why it appeared incapable of conceiving of democratic reform 'in the round'. This article seeks to explain these apparent paradoxes, however, through utilising the notion of 'macular degeneration'. In this analysis, the perceived democratic blind spot of New Labour at Westminster is connected to a democratic peripheral vision, which has envisaged innovative participatory and decentred initiatives in governance beyond Westminster

    Boundary Limitation of Wavenumbers in Taylor-Vortex Flow

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    We report experimental results for a boundary-mediated wavenumber-adjustment mechanism and for a boundary-limited wavenumber-band of Taylor-vortex flow (TVF). The system consists of fluid contained between two concentric cylinders with the inner one rotating at an angular frequency Ω\Omega. As observed previously, the Eckhaus instability (a bulk instability) is observed and limits the stable wavenumber band when the system is terminated axially by two rigid, non-rotating plates. The band width is then of order ϵ1/2\epsilon^{1/2} at small ϵ\epsilon (ϵΩ/Ωc1\epsilon \equiv \Omega/\Omega_c - 1) and agrees well with calculations based on the equations of motion over a wide ϵ\epsilon-range. When the cylinder axis is vertical and the upper liquid surface is free (i.e. an air-liquid interface), vortices can be generated or expelled at the free surface because there the phase of the structure is only weakly pinned. The band of wavenumbers over which Taylor-vortex flow exists is then more narrow than the stable band limited by the Eckhaus instability. At small ϵ\epsilon the boundary-mediated band-width is linear in ϵ\epsilon. These results are qualitatively consistent with theoretical predictions, but to our knowledge a quantitative calculation for TVF with a free surface does not exist.Comment: 8 pages incl. 9 eps figures bitmap version of Fig

    Evaluation of Phage Display Discovered Peptides as Ligands for Prostate-Specific Membrane Antigen (PSMA)

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    The aim of this study was to identify potential ligands of PSMA suitable for further development as novel PSMA-targeted peptides using phage display technology. The human PSMA protein was immobilized as a target followed by incubation with a 15-mer phage display random peptide library. After one round of prescreening and two rounds of screening, high-stringency screening at the third round of panning was performed to identify the highest affinity binders. Phages which had a specific binding activity to PSMA in human prostate cancer cells were isolated and the DNA corresponding to the 15-mers were sequenced to provide three consensus sequences: GDHSPFT, SHFSVGS and EVPRLSLLAVFL as well as other sequences that did not display consensus. Two of the peptide sequences deduced from DNA sequencing of binding phages, SHSFSVGSGDHSPFT and GRFLTGGTGRLLRIS were labeled with 5-carboxyfluorescein and shown to bind and co-internalize with PSMA on human prostate cancer cells by fluorescence microscopy. The high stringency requirements yielded peptides with affinities KD∼1 μM or greater which are suitable starting points for affinity maturation. While these values were less than anticipated, the high stringency did yield peptide sequences that apparently bound to different surfaces on PSMA. These peptide sequences could be the basis for further development of peptides for prostate cancer tumor imaging and therapy. © 2013 Shen et al

    Orchestrating learning activities using the CADMOS learning design tool

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    This paper gives an overview of CADMOS (CoursewAre Development Methodology for Open instructional Systems), a graphical IMS-LD Level A & B compliant learning design (LD) tool, which promotes the concept of “separation of concerns” during the design process, via the creation of two models: the conceptual model, which describes the learning activities and the corresponding learning resources, and the flow model, which describes the orchestration of these activities. According to the feedback from an evaluation case study with 36 participants, reported in this paper, CADMOS is a user-friendly tool that allows educational practitioners to design flows of learning activities using a layered approach

    Antibodies in healthcare personnel following severe acute respiratory syndrome coronavirus virus 2 (SARS-CoV-2) infection

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    In a prospective cohort of healthcare personnel (HCP), we measured severe acute respiratory syndrome coronavirus virus 2 (SARS-CoV-2) nucleocapsid IgG antibodies after SARS-CoV-2 infection. Among 79 HCP, 68 (86%) were seropositive 14-28 days after their positive PCR test, and 54 (77%) of 70 were seropositive at the 70-180-day follow-up. Many seropositive HCP (95%) experienced an antibody decline by the second visit
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