1,708 research outputs found
PSS8 Use of consumer market research panels to generate prevalence and disease burden estimates in data-sparse diseases: a case study in severe Chronic Hand Eczema
Farrando, Jordi;Febles, Maria Dolors ;Henrich, Jordi;TarrasĂł, Olga ;Fuertes, J.C.;PĂ©rez, S
Rectification Mechanism in Di-Block Oligomer Molecular Diodes
We investigated a mechanism of rectification in di-block oligomer diode
molecules that have recently been synthesized and showed a pronounced asymmetry
in the measured I-V spectrum. The observed rectification effect is due to the
resonant nature of electron transfer in the system and localization properties
of bound state wave functions of resonant states of the tunneling electron
interacting with asymmetric molecule in an electric field. The asymmetry of the
tunneling wave function is enhanced or weakened depending on the polarity of
applied bias. The conceptually new theoretical approach, the Green's function
theory of sub-barrier scattering, is able to provide a physically transparent
explanation of this rectification effect based on the concept of the bound
state spectrum of a tunneling electron. The theory predicts the characteristic
features of the I-V spectrum in qualitative agreement with experiment
Achieving consensus through professionalized head nods: The role of nodding in service encounters in Japan
While the interactional functions of head nodding in everyday Japanese conversation have been frequently studied, a discourse on head nodding as a professional communicative practice has yet to be explored. With the method of multimodal conversation analysis, the current study examines the role of nodding in a particular professional-client setting, namely, hair salon interactions. My interest specifically lies in the frequent occurrence of synchronized head nods during the “service-assessment sequence,” where both service provider and customer inspect and determine whether the completed work is adequate. I pursue mechanisms of synchronized head nods by revealing exactly how participants collaborate in producing a nod, and how their verbal actions may at times be designed accordingly. In doing so, the study provides insight into what consensus may look like at service encounters in Japan, and discusses how such nodding practices may contribute to a satisfactory closure of a business negotiation
Transition between nuclear and quark-gluon descriptions of hadrons and light nuclei
We provide a perspective on studies aimed at observing the transition between
hadronic and quark-gluonic descriptions of reactions involving light nuclei. We
begin by summarizing the results for relatively simple reactions such as the
pion form factor and the neutral pion transition form factor as well as that
for the nucleon and end with exclusive photoreactions in our simplest nuclei. A
particular focus will be on reactions involving the deuteron. It is noted that
a firm understanding of these issues is essential for unraveling important
structure information from processes such as deeply virtual Compton scattering
as well as deeply virtual meson production. The connection to exotic phenomena
such as color transparency will be discussed. A number of outstanding
challenges will require new experiments at modern facilities on the horizon as
well as further theoretical developments.Comment: 37 pages, 17 figures, submitted to Reports on Progress in Physic
Co-directional replication-transcription conflicts lead to replication restart
August 24, 2011Head-on encounters between the replication and transcription machineries on the lagging DNA strand can lead to replication fork arrest and genomic instability1, 2. To avoid head-on encounters, most genes, especially essential and highly transcribed genes, are encoded on the leading strand such that transcription and replication are co-directional. Virtually all bacteria have the highly expressed ribosomal RNA genes co-directional with replication3. In bacteria, co-directional encounters seem inevitable because the rate of replication is about 10–20-fold greater than the rate of transcription. However, these encounters are generally thought to be benign2, 4, 5, 6, 7, 8, 9. Biochemical analyses indicate that head-on encounters10 are more deleterious than co-directional encounters8 and that in both situations, replication resumes without the need for any auxiliary restart proteins, at least in vitro. Here we show that in vivo, co-directional transcription can disrupt replication, leading to the involvement of replication restart proteins. We found that highly transcribed rRNA genes are hotspots for co-directional conflicts between replication and transcription in rapidly growing Bacillus subtilis cells. We observed a transcription-dependent increase in association of the replicative helicase and replication restart proteins where head-on and co-directional conflicts occur. Our results indicate that there are co-directional conflicts between replication and transcription in vivo. Furthermore, in contrast to the findings in vitro, the replication restart machinery is involved in vivo in resolving potentially deleterious encounters due to head-on and co-directional conflicts. These conflicts probably occur in many organisms and at many chromosomal locations and help to explain the presence of important auxiliary proteins involved in replication restart and in helping to clear a path along the DNA for the replisome.Biotechnology and Biological Sciences Research Council (Great Britain) (Grant BB/E006450/1)Wellcome Trust (London, England) (Grant 091968/Z/10/Z)National Institutes of Health (U.S.) (Grant GM41934)National Institutes of Health (U.S.) (Postdoctoral Fellowship GM093408)Biotechnology and Biological Sciences Research Council (Great Britain) (Sabbatical Visit
Switching between different vortex states in 2-dimensional easy-plane magnets due to an ac magnetic field
Using a discrete model of 2-dimensional easy-plane classical ferromagnets, we
propose that a rotating magnetic field in the easy plane can switch a vortex
from one polarization to the opposite one if the amplitude exceeds a threshold
value, but the backward process does not occur. Such switches are indeed
observed in computer simulations.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Let
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