4,699 research outputs found
Excitations in confined helium
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
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
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]. âWorking with/in institutions: how policy enactment in widening participation is shaped through practitionersâ experience.â British Journal of Sociology of Education 42 (2): 287â303). This article presents practitionersâ 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 practitionersâ 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 âprofessionalâ 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
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 doesnât 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
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 17.8â”M and 22.5â”M, respectively
Probabilistic Model Checking for Energy Analysis in Software Product Lines
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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