First-principles GW calculations for DNA and RNA nucleobases

On the basis of first-principles GW calculations, we study the quasiparticle properties of the guanine, adenine, cytosine, thymine, and uracil DNA and RNA nucleobases. Beyond standard G0W0 calculations, starting from Kohn-Sham eigenstates obtained with (semi)local functionals, a simple self-consistency on the eigenvalues allows to obtain vertical ionization energies and electron affinities within an average 0.11 eV and 0.18 eV error respectively as compared to state-of-the-art coupled-cluster and multi-configurational perturbative quantum chemistry approaches. Further, GW calculations predict the correct \pi -character of the highest occupied state, thanks to several level crossings between density functional and GW calculations. Our study is based on a recent gaussian-basis implementation of GW with explicit treatment of dynamical screening through contour deformation techniques.Comment: 5 pages, 3 figure

Base sequence dependent sliding of proteins on DNA

The possibility that the sliding motion of proteins on DNA is influenced by the base sequence through a base pair reading interaction, is considered. Referring to the case of the T7 RNA-polymerase, we show that the protein should follow a noise-influenced sequence-dependent motion which deviate from the standard random walk usually assumed. The general validity and the implications of the results are discussed.Comment: 12 pages, 3 figure

Safety and efficacy of an oral insulin (Capsulin) in patients with early‐stage type 2 diabetes: a dose‐ranging phase IIb study

Aim This randomised, twelve-week open-label study compared the pharmacodynamic properties of different dose of regular human insulin administered in capsule form twice daily. Methods 100 persons (48 male, 52 female) with type 2 diabetes on metformin completed the study according to protocol. Mean (SD) age 48.5 (6.7) years, BMI 25.7 (2.8) kg/m2, HbA1c 8.10 (0.65) %. Subjects randomised on admission were assigned to one of three groups receiving 75iu BD of formulated regular insulin or 150iu insulin BD, or 300iu BD in enteric-coated capsules. Primary and secondary endpoints were change from baseline in HbA1c and FPG respectively. A total of 100 subjects from 15 different centres completed the study within protocol. Results The study met its primary clinical endpoint of a decrease in HbA1c ≥ 0.5% (least square mean decrease 0.52%; p = 0.004, median decrease 0.6) in the dose group receiving 150iu BD. In a subset of this population, with starting HbA1c values between 9 and 9.5%, an average decrease of 1.575% was seen. In the total population, least square mean decreases in HbA1c for groups 75iu BD and 300iu BD were -0.11% and -0.42% respectively. Mean change in FPG in the 150iu BD dose group was -18.8mg/dL (p = 0.017) and -14.8 and -2.7mg/dL for groups 75iu BD and 300iu BD respectively. A decrease of 20% for triglycerides (-40 mg/dL) was seen in the 150iu BD dose group . No significant increases in body weight were observed, and significant decreases in systolic blood pressure were seen in all groups. No serious treatment-related adverse events were recorded, and no incidence of hypoglycaemia was reported throughout the whole twelve-week study period. Conclusions Capsulin oral insulin administered twice per day at a dose of 150iu per capsule is safe, with no confirmed treatment-linked hypoglycaemic events, and results in significant decreases from baseline in HbA1c, Fasting Plasma Glucose and triglycerides

Force Distribution in a Granular Medium

We report on systematic measurements of the distribution of normal forces exerted by granular material under uniaxial compression onto the interior surfaces of a confining vessel. Our experiments on three-dimensional, random packings of monodisperse glass beads show that this distribution is nearly uniform for forces below the mean force and decays exponentially for forces greater than the mean. The shape of the distribution and the value of the exponential decay constant are unaffected by changes in the system preparation history or in the boundary conditions. An empirical functional form for the distribution is proposed that provides an excellent fit over the whole force range measured and is also consistent with recent computer simulation data.Comment: 6 pages. For more information, see http://mrsec.uchicago.edu/granula

Optimal network topologies for local search with congestion

The problem of searchability in decentralized complex networks is of great importance in computer science, economy and sociology. We present a formalism that is able to cope simultaneously with the problem of search and the congestion effects that arise when parallel searches are performed, and obtain expressions for the average search cost--written in terms of the search algorithm and the topological properties of the network--both in presence and abscence of congestion. This formalism is used to obtain optimal network structures for a system using a local search algorithm. It is found that only two classes of networks can be optimal: star-like configurations, when the number of parallel searches is small, and homogeneous-isotropic configurations, when the number of parallel searches is large.Comment: 4 pages. Final version accepted in PR

A genetic algorithm based approach to fiber design for high coherence and large bandwidth supercontinuum generation

We present a new approach to the design of optical microstructured fibers that have group velocity dispersion (GVD) and effective nonlinear coefficient (gamma ) tailored for supercontinuum (SC) generation. This hybrid approach combines a genetic algorithm (GA) with pulse propagation modeling, but without include it into the GA loop, to allow the efficient design of fibers that are capable of generating highly coherent and large bandwidth SC in the mid-infrared (Mid-IR) spectrum. To the best of our knowledge, this is the first use of a GA to design fiber for SC generation. We investigate the robustness of these fiber designs to variation in the fiber's structural parameters. The optimized fiber structure based on a type of tellurite glass (70TeO(2) - 10 Na(2)O - 20 ZnF(2)) is predicted to have near-zero group velocity dispersion (< +/-2 ps/nm/km) from 2 to 3 microm, and a effective nonlinear coefficient of gamma approximately 174 W(-1)km(-1) at 2 microm. The SC output of this fiber shows a significant bandwidth and coherence increase compare to a fiber with a single zero group velocity dispersion wavelength at 2 microm.Wen Qi Zhang, Shahraam Afshar V. and Tanya M. Monr

The microbiome of the gastrointestinal tract of a range-shifting marine herbivorous fish

Globally, marine species\u27 distributions are being modified due to rising ocean temperatures. Increasing evidence suggests a circum-global pattern of poleward extensions in the distributions of many tropical herbivorous species, including the ecologically important rabbitfis

Ultrafast Raman laser mode-locked by nanotubes

We demonstrate passive mode-locking of a Raman fiber laser using a nanotube-based saturable absorber coupled to a net normal dispersion cavity. This generates highly chirped 500 ps pulses. These are then compressed down to 2 ps , with 1.4 kW peak power, making it a simple wavelength-versatile source for various applications