4,699 research outputs found

    Excitations in confined helium

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    We design models for helium in matrices like aerogel, Vycor or Geltech from a manifestly microscopic point of view. For that purpose, we calculate the dynamic structure function of 4He on Si substrates and between two Si walls as a function of energy, momentum transfer, and the scattering angle. The angle--averaged results are in good agreement with the neutron scattering data; the remaining differences can be attributed to the simplified model used here for the complex pore structure of the materials. A focus of the present work is the detailed identification of coexisting layer modes and bulk--like excitations, and, in the case of thick films, ripplon excitations. Involving essentially two--dimensional motion of atoms, the layer modes are sensitive to the scattering angle.Comment: Phys. Rev. B (2003, in press

    The Relationship between Adverse Childhood Experiences (ACEs) and Intrinsic Religiosity in Southern Appalachia

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    The present exploratory study examined adverse childhood experiences and religiosity in a sample of individuals from Southern Appalachia. Self-reports of childhood adversity and intrinsic religion were obtained from 167 individuals. Results showed that fifty-five percent had not experienced a childhood adversity while forty-three percent had experienced one to five episodes. Although a little under half the sample had one or more adverse experiences, there was no significant relationship between ACEs and intrinsic religion (r= -.037, p= .631). Sex and intrinsic religion were significantly related in that men endorsed the use of intrinsic religiosity more than women (t(165)= -2.28, p= .005)

    How professionalisation of outreach practitioners could improve the quality of evaluation and evidence:a proposal

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    Professionalising outreach and evaluation work would enhance the quality and rigour of provision, benefit widening participation students and achieve regulatory requirements (Bowes et al. [2019]. The National Collaborative Outreach Programme End of Phase 1 report for the national formative and impact evaluations. Office for Students; Rainford [2020]. “Working with/in institutions: how policy enactment in widening participation is shaped through practitioners’ experience.” British Journal of Sociology of Education 42 (2): 287–303). This article presents practitioners’ experiences of how social justice can often feel unaligned to the technical expertise required in rigorous project design and evaluation. Professionalising outreach would achieve both improved practice and meet practitioners’ needs for development and a united professional voice. A professional body sharing standard methods of practice, offering CPD and skills would elevate outreach practitioners to a ‘professional’ standing (Eraut [1994]. Developing professional knowledge and competence. Falmer Press)

    FORMULASI DAN UJI AKTIVITAS ANTIBAKTERI KRIM EKSTRAK ETANOL HERBA SELEDRI (Apium graveolens L.) TERHADAP BAKTERI Staphylococcus aureus

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    ABSTRACTCelery herbs (Apium graveolens L.) have content flavonoid, saponin and tannin. Flavonoids have anti-inflammatory properties, antioxidants and antibacterials. This study aims to determine whether the ethanol extract of celery herbs can be formulated into cream preparations, test the quality of preparations at concentrations of 5%, 10% and 15%. These methods of research are experimental laboratories by making the supply of self-sustaining herbal celery ethanol extract cream and testing the quality of the cream preparation,  as well as testing of antibacterial activity was carried out using the liquid dilution method and measuring value of  Minimum Inhibitory Concentration  and Minimum Bactericidal Concentration using a UV-Vis Spectrophotometer. This research shows that celery herbs ethanol extract can be formulated into cream preparations, fulfilling quality test of organoleptic, scatter power, adhesion and cycling test, but that doesn’t meet the requirements for homogeneity tests and pH tests and has antibacterial activity which not only inhibits but kills bacteria in preparations of 5% and 15%Keywords: Cream Celery herb extract, Antibacterial, Staphylococcus aureus, UV-Vis spectrophotometer ABSTRAK Herba Seledri (Apium graveolens L.) memiliki kandungan flavonoid, saponin dan tannin. Flavonoid memiliki khasiat sebagai antiinflamasi, antioksidan dan antibakteri. Penelitian ini bertujuan untuk mengetahui apakah ekstrak etanol herba Seledri dapat diformulasikan menjadi sediaan krim, menguji mutu sediaan pada konsentrasi 5%, 10% dan 15%. Metode penelitian ini experimental laboratorium dengan membuat Sediaan Krim Ekstrak Etanol Herba Seledri dan menguji mutu sediaan krim, serta   menguji aktivitas antibakteri menggunakan metode dilusi cair dan mengukur nilai KBM dan KHM menggunakan Spektrofotometer UV-Vis. Hasil penelitian menujukkan bahwa ekstrak etanol herba Seledri dapat diformulasikan menjadi sediaan krim, memenuhi uji mutu sediaan organoleptik, daya, sebar, daya hambat dan stabilitas  namun tidak memenuhi persyaratan untuk uji homogenitas dan uji pH serta mempunyai aktivitas antibakteri yang membunuh bakteri pada sediaan berkonsentrasi 5% dan 15%.Kata Kunci : Krim Ekstrak herba Seledri, Antibakteri, Staphylococcus aureus, Spektrofotometer UV-Vi

    Metabolomics-guided isolation of anti-trypanosomal metabolites from the endophytic fungus Lasiodiplodia theobromae

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    Fungal endophytes offer diverse and unique secondary metabolites, making these organisms potential sources of promising drug leads. The application of high-resolution-liquid chromatography mass spectrometry and nuclear magnetic resonance-based metabolomics to fungal endophytes is practical in terms of dereplication studies and the mining of bioactive compounds. In this paper, we report the application of metabolomics in parallel with anti-trypanosomal assays to determine the ideal conditions for the medium-scale fermentation of the endophyte Lasiodiplodia theobromae. The (1)H NMR comparison between the active versus inactive fractions identified several unique chemical fingerprints belonging to the active fractions. Furthermore, by integrating high-resolution-liquid chromatography mass spectrometry data with multivariate data analysis, such as orthogonal partial least squares-discriminant analysis (OPLS-DA) and the bioactivity results of the fractions of L. theobromae, the anti-trypanosomal agents were easily discerned. With available databases such as Antibase and Dictionary of Natural Products coupled to MZmine through in-house algorithms optimized in our laboratory, the predicted metabolites were readily identified prior to isolation. Fractionation was performed on the active fractions and three known compounds were isolated, namely, cladospirone B, desmethyl-lasiodiplodin, and R-(-)-mellein. Cladospirone B and desmethyl-lasiodiplodin were among the predicted compounds generated by the OPLS-DA S-plot, and these compounds exhibited good activity against Trypanosoma brucei brucei with minimum inhibitory concentrations of 17.8 ”M and 22.5 ”M, respectively

    Probabilistic Model Checking for Energy Analysis in Software Product Lines

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    In a software product line (SPL), a collection of software products is defined by their commonalities in terms of features rather than explicitly specifying all products one-by-one. Several verification techniques were adapted to establish temporal properties of SPLs. Symbolic and family-based model checking have been proven to be successful for tackling the combinatorial blow-up arising when reasoning about several feature combinations. However, most formal verification approaches for SPLs presented in the literature focus on the static SPLs, where the features of a product are fixed and cannot be changed during runtime. This is in contrast to dynamic SPLs, allowing to adapt feature combinations of a product dynamically after deployment. The main contribution of the paper is a compositional modeling framework for dynamic SPLs, which supports probabilistic and nondeterministic choices and allows for quantitative analysis. We specify the feature changes during runtime within an automata-based coordination component, enabling to reason over strategies how to trigger dynamic feature changes for optimizing various quantitative objectives, e.g., energy or monetary costs and reliability. For our framework there is a natural and conceptually simple translation into the input language of the prominent probabilistic model checker PRISM. This facilitates the application of PRISM's powerful symbolic engine to the operational behavior of dynamic SPLs and their family-based analysis against various quantitative queries. We demonstrate feasibility of our approach by a case study issuing an energy-aware bonding network device.Comment: 14 pages, 11 figure
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