Low complexity method for large-scale self-consistent ab initio electronic-structure calculations without localization

A novel low complexity method to perform self-consistent electronic-structure calculations using the Kohn-Sham formalism of density functional theory is presented. Localization constraints are neither imposed nor required thereby allowing direct comparison with conventional cubically scaling algorithms. The method has, to date, the lowest complexity of any algorithm for an exact calculation. A simple one-dimensional model system is used to thoroughly test the numerical stability of the algorithm and results for a real physical system are also given

Revealing the role of electrons and phonons in the ultrafast recovery of charge density wave correlations in 1TT-TiSe2_2

Using time- and angle-resolved photoemission spectroscopy with selective near- and mid-infrared photon excitations, we investigate the femtosecond dynamics of the charge density wave (CDW) phase in 1$T$-TiSe$_2$, as well as the dynamics of CDW fluctuations at 240 K. In the CDW phase, we observe the coherent oscillation of the CDW amplitude mode. At 240 K, we single out an ultrafast component in the recovery of the CDW correlations, which we explain as the manifestation of electron-hole correlations. Our momentum-resolved study of femtosecond electron dynamics supports a mechanism for the CDW phase resulting from the cooperation between the interband Coulomb interaction, the mechanism of excitonic insulator phase formation, and electron-phonon coupling.Comment: 9 pages, 6 figure

Mechanisms of vascular smooth muscle contraction and the basis for pharmacologic treatment of smooth muscle disorders

The smooth muscle cell directly drives the contraction of the vascular wall and hence regulates the size of the blood vessel lumen. We review here the current understanding of the molecular mechanisms by which agonists, therapeutics, and diseases regulate contractility of the vascular smooth muscle cell and we place this within the context of whole body function. We also discuss the implications for personalized medicine and highlight specific potential target molecules that may provide opportunities for the future development of new therapeutics to regulate vascular function.Accepted manuscrip

The Active Management of Impending Cephalopelvic Disproportion in Nulliparous Women at Term: A Case Series

Background. The Active Management of Risk in Pregnancy at Term (AMOR-IPAT) protocol has been associated in several studies with significant reductions of group cesarean delivery rate. Present within each of these studies were nulliparous women with risk factors for cephalopelvic disproportion. Risk factors for cephalopelvic disproportion in nulliparous women are especially important because they represent the precursors for the most common indication for primary cesarean delivery. Cases. Three examples of exposure of urban nulliparous women to the AMOR-IPAT protocol are presented. Each woman's risk factor profile for Cephalopelvic Disproportion (CPD) was used to estimate her Upper Limit of Optimal Time of Vaginal Delivery for CPD (UL-OTDcpd). Labor management and clinical outcomes for each case are presented. A simple table summarizing induction rates and birth outcome rates of exposed versus nonexposed nulliparous women is also presented. Conclusion. Because the mode of delivery of the first birth substantially impacts birth options in later pregnancies, the impact of AMOR-IPAT on nulliparous patients is particularly important. Determining the UL-OTDcpd in nulliparous patients, and carefully inducing each patient who has not entered labor by her UL-OTDcpd, may be an effective way of lowering rates of cesarean delivery in nulliparous women

Effects of a multi-component exercise program and calcium–vitamin-D3-fortified milk on bone mineral density in older men : a randomised controlled trial

Summary We examined the independent and combined effects of a multi-component exercise program and calcium&ndash;vitamin-D3-fortified milk on bone mineral density (BMD) in older men. Exercise resulted in a 1.8% net gain in femoral neck BMD, but additional calcium&ndash;vitamin D3 did not enhance the response in this group of older well-nourished men.Introduction This 12-month randomised controlled trial assessed whether calcium&ndash;vitamin-D3-fortified milk could enhance the effects of a multi-component exercise program on BMD in older men.Methods Men (n&thinsp; =&thinsp;180) aged 50&ndash;79 years were randomised into: (1) exercise + fortified milk; (2) exercise; (3) fortified milk; or (4) controls. Exercise consisted of high intensity progressive resistance training with weight-bearing impact exercise. Men assigned to fortified milk consumed 400 mL/day of low fat milk providing an additional 1,000 mg/day calcium and 800 IU/day vitamin D3. Femoral neck (FN), total hip, lumbar spine and trochanter BMD and body composition (DXA), muscle strength 25-hydroxyvitamin D and parathyroid hormone (PTH) were assessed.Results There were no exercise-by-fortified milk interactions at any skeletal site. Exercise resulted in a 1.8% net gain in FN BMD relative to no-exercise (p&thinsp;&lt;&thinsp;0.001); lean mass (0.6 kg, p&thinsp;&lt;&thinsp;0.05) and muscle strength (20&ndash;52%, p&thinsp;&lt;&thinsp;0.001) also increased in response to exercise. For lumbar spine BMD, there was a net 1.4&ndash;1.5% increase in all treatment groups relative to controls (all p&thinsp;&lt;&thinsp;0.01). There were no main effects of fortified milk at any skeletal site.Conclusion A multi-component community-based exercise program was effective for increasing FN BMD in older men, but additional calcium&ndash;vitamin D3 did not enhance the osteogenic response.<br /

Titan's atmosphere as observed by Cassini/VIMS solar occultations: CH4_4, CO and evidence for C2_2H6_6 absorption

We present an analysis of the VIMS solar occultations dataset, which allows us to extract vertically resolved information on the characteristics of Titan's atmosphere between 100-700 km with a characteristic vertical resolution of 10 km. After a series of data treatment procedures, 4 occultations out of 10 are retained. This sample covers different seasons and latitudes of Titan. The transmittances show clearly the evolution of the haze and detect the detached layer at 310 km in Sept. 2011 at mid-northern latitudes. Through the inversion of the transmission spectra with a line-by-line radiative transfer code we retrieve the vertical distribution of CH$_4$ and CO mixing ratio. The two methane bands at 1.4 and 1.7 {\mu}m are always in good agreement and yield an average stratospheric abundance of $1.28\pm0.08$%. This is significantly less than the value of 1.48% obtained by the GCMS/Huygens instrument. The analysis of the residual spectra after the inversion shows that there are additional absorptions which affect a great part of the VIMS wavelength range. We attribute many of these additional bands to gaseous ethane, whose near-infrared spectrum is not well modeled yet. Ethane contributes significantly to the strong absorption between 3.2-3.5 {\mu}m that was previously attributed only to C-H stretching bands from aerosols. Ethane bands may affect the surface windows too, especially at 2.7 {\mu}m. Other residual bands are generated by stretching modes of C-H, C-C and C-N bonds. In addition to the C-H stretch from aliphatic hydrocarbons at 3.4 {\mu}m, we detect a strong and narrow absorption at 3.28 {\mu}m which we tentatively attribute to the presence of PAHs in the stratosphere. C-C and C-N stretching bands are possibly present between 4.3-4.5 {\mu}m. Finally, we obtain the CO mixing ratio between 70-170 km. The average result of $46\pm16$ ppm is in good agreement with previous studies.Comment: 51 pages, 28 figure