1,801 research outputs found
Influence of a fluorobenzene nucleobase analogue on the conformational flexibility of RNA studied by molecular dynamics simulations
Chemically modified bases are frequently used to stabilize nucleic acids, to study the driving forces for nucleic acid structure formation and to tune DNA and RNA hybridization conditions. In particular, fluorobenzene and fluorobenzimidazole base analogues can act as universal bases able to pair with any natural base and to stabilize RNA duplex formation. Although these base analogues are compatible with an A-form RNA geometry, little is known about the influence on the fine structure and conformational dynamics of RNA. In the present study, nano-second molecular dynamics (MD) simulations have been performed to characterize the dynamics of RNA duplexes containing a central 1'-deoxy-1'-(2,4-difluorophenyl)-ß-D-ribofuranose base pair or opposite to an adenine base. For comparison, RNA with a central uridine:adenine pair and a 1'-deoxy-1'-(phenyl)-ß-D-ribofuranose opposite to an adenine was also investigated. The MD simulations indicate a stable overall A-form geometry for the RNAs with base analogues. However, the presence of the base analogues caused a locally enhanced mobility of the central bases inducing mainly base pair shear and opening motions. No stable ‘base-paired’ geometry was found for the base analogue pair or the base analogue:adenine pairs, which explains in part the universal base character of these analogues. Instead, the conformational fluctuations of the base analogues lead to an enhanced accessibility of the bases in the major and minor grooves of the helix compared with a regular base pair
Strategy Development of Facility Management General Contracting for Schlumberger Ltd.
CEMSThe project in cooperation with Schlumberger serves as part of the long-term vision of
Schlumberger to reduce facility management suppliers at its locations in Russia and CIS
countries. The goal is to reduce costs and increase transparency. To create a basis for this
development, a supplier selection process was designed. Moreover, the market, potential
suppliers as well as cost drivers were analysed. The outcome is a tested model that exhibits
that a current reduction of facility management suppliers in Russia as planned by
Schlumberger is not feasible. However, the model will be the basis for future evaluations of
suppliers
Approving job profiles for curriculum profiles in health care programs : a study on process and product quality
A study evaluated the approach used for validation of job profiles for curriculum development in three health care programs in the Netherlands: dietetics, podotherapy, and activity therapy. It also evaluated the quality of these job profiles and the relation between process and product quality. The validation approach used was a practical application of a small group strategy that consisted of three parts: information, deliberation, and consensus. Data were used from three cases. In these cases, 12, 10, and 11 persons with health care institutions or educational institutions were present. Six questionnaires collected data on the following: (1) personal characteristics, motives and expectations, the information document, and the draft job profile; (2) opinions on issues and expected consensus; (3) communication rules; (4) the decision-making process; (5) consensus on components of and opinions on the quality of the validated job profile; and (6) evaluation of the validation approach. Findings indicated that the validation approach was satisfying. Although there was a considerable amount of prior agreement with the draft job profile components, the validation sessions created an even greater agreement with the final job profile components. The validation approach was also satisfying with regard to product quality. The process quality was scored less positively. The study showed that process and product quality were significantly related
The ornithological diaries of Helmut Sick (1910 - 1991)
On the 10th of January 2010 Helmut Sick, the German-Brazilian explorer of neotropical birds would have had his 100th anniversary. He made his PhD under supervision of Erwin Stresemann in 1937 about the structure of bird feathers. 1939 he joined a three months expedition to Brazil but was so fascinated about the bird life that he stayed much longer and in 1952 he became citizen of Brazil. Helmut Sick was director at the National Museum Boa Vista and was professor for zoology an the State University in Rio. He became member of the Academia Brasileira de Ciências und honorary citizen of Rio de Janeiro. His probably most important book were the two volumes of „Ornitologia brasiliera, uma introduÇão“, which has been revised in 1993 in an English version “Birds in Brazil. A natural history“. Over 68 years Helmut Sick conducted an ornithological diary with very detailed, sometimes even artistic descriptions of his observations. His notes between 1923 and 1938 comprise 12 diary books with 80 pages each. The authors secured the material and looked through it. Here a short description of the contents is given. A publication list and more material are available online (see bottom of the text). Helmut Sick died in a traffic accident on 5th March 1991 in Rio de Janeiro
Deconfinement and Chiral Symmetry Restoration in an SU(3) Gauge Theory with Adjoint Fermions
We analyze the finite temperature phase diagram of with fermions in the
adjoint representation. The simulations performed with four dynamical Majorana
fermions show that the deconfinement and chiral phase transitions occur at two
distinct temperatures. While the deconfinement transition is first order at T_d
we find evidence for a continuous chiral transition at a higher temperature
$T_c ~ 8 T_d. We observe a rapid change of bulk thermodynamic observables at
T_d which reflects the increase in the number of degrees of freedom. However,
these show little variation at T_c, where the fermion condensate vanishes. We
also analyze the potential between static fundamental and adjoint charges in
all three phases and extract the corresponding screening masses above T_d.Comment: 19 pages, LaTeX2e File, 9 Postscript figure
Predictors of Social Physique Anxiety in Elite Female Youth Athletes
The purpose of this study was to examine predictors of social physique anxiety (SPA). SPA, self-esteem, body-esteem, public body consciousness (PBC) and percent body fat (%BF) were assessed with elite female youth athletes (N = 68) competing in either figure skating, soccer or gymnastics. Stepwise multiple regression analyses, controlling for BF%, accounted for 59% of the variance in SPA. Self-esteem entered first, and BF%, followed by body-esteem and PBC. The psychological variables accounted for 57% of the variance with self-esteem contributing the most (R square change = 45%). Contrary to previous research, BF% did not significantly contribute to SPA. Additionally, a MANOVA and follow- up ANOVA and Scheffe\u27s tests revealed significant sport differences among SPA, self-esteem, and body-esteem
Concept for a Time-of-Flight Small Angle Neutron Scattering Instrument at the European Spallation Source
A new Small Angle Neutron Scattering instrument is proposed for the European
Spallation Source. The pulsed source requires a time-of-flight analysis of the
gathered neutrons at the detector. The optimal instrument length is found to be
rather large, which allows for a polarizer and a versatile collimation. The
polarizer allows for studying magnetic samples and incoherent background
subtraction. The wide collimation will host VSANS and SESANS options that
increase the resolution of the instrument towards um and tens of um,
respectively. Two 1m2 area detectors will cover a large solid angle
simultaneously. The expected gains for this new instrument will lie in the
range between 20 and 36, depending on the assessment criteria, when compared to
up-to-date reactor based instruments. This will open new perspectives for fast
kinetics, weakly scattering samples, and multi-dimensional contrast variation
studies.Comment: 18 pages, 10 figure
- …