Coulomb correlation in presence of spin-orbit coupling: application to plutonium

Attempts to go beyond the local density approximation (LDA) of Density Functional Theory (DFT) have been increasingly based on the incorporation of more realistic Coulomb interactions. In their earliest implementations, methods like LDA+$U$, LDA + DMFT (Dynamical Mean Field Theory), and LDA+Gutzwiller used a simple model interaction $U$. In this article we generalize the solution of the full Coulomb matrix involving $F^{(0)}$ to $F^{(6)}$ parameters, which is usually presented in terms of an $\ell m_\ell$ basis, into a $jm_{j}$ basis of the total angular momentum, where we also include spin-orbit coupling; this type of theory is needed for a reliable description of $f$-state elements like plutonium, which we use as an example of our theory. Close attention will be paid to spin-flip terms, which are important in multiplet theory but that have been usually neglected in these kinds of studies. We find that, in a density-density approximation, the $jm_j$ basis results provide a very good approximation to the full Coulomb matrix result, in contrast to the much less accurate results for the more conventional $\ell m_\ell$ basis

Polyphosphate granule biogenesis is temporally and functionally tied to cell cycle exit during starvation in Pseudomonas aeruginosa

Polyphosphate (polyP) granule biogenesis is an ancient and ubiquitous starvation response in bacteria. Although the ability to make polyP is important for survival during quiescence and resistance to diverse environmental stresses, granule genesis is poorly understood. Using quantitative microscopy at high spatial and temporal resolution, we show that granule genesis in Pseudomonas aeruginosa is tightly organized under nitrogen starvation. Following nucleation as many microgranules throughout the nucleoid, polyP granules consolidate and become transiently spatially organized during cell cycle exit. Between 1 and 3 h after nitrogen starvation, a minority of cells have divided, yet the total granule number per cell decreases, total granule volume per cell dramatically increases, and individual granules grow to occupy diameters as large as ∼200 nm. At their peak, mature granules constitute ∼2% of the total cell volume and are evenly spaced along the long cell axis. Following cell cycle exit, granules initially retain a tight spatial organization, yet their size distribution and spacing relax deeper into starvation. Mutant cells lacking polyP elongate during starvation and contain more than one origin. PolyP promotes cell cycle exit by functioning at a step after DNA replication initiation. Together with the universal starvation alarmone (p)ppGpp, polyP has an additive effect on nucleoid dynamics and organization during starvation. Notably, cell cycle exit is temporally coupled to a net increase in polyP granule biomass, suggesting that net synthesis, rather than consumption of the polymer, is important for the mechanism by which polyP promotes completion of cell cycle exit during starvation

A theory of robust experiments for choice under uncertainty

Thought experiments are commonly used in the theory of behavior in the presence of risk and uncertainty to test the plausibility of proposed axiomatic postulates. The prototypical examples of the former are the Allais experiments and of the latter are the Ellsberg experiments. Although the lotteries from the former have objectively specified probabilities, the participants in both kinds of experiments may be susceptible to small deviations in their subjective beliefs. These may result from a variety of factors that are difficult to check in an experimental setting: including deviations in the understanding and trust regarding the experiment, its instructions and its method. Intuitively, an experiment is robust if it is tolerant to small deviations in subjective beliefs in models that are in an appropriate way close to the analyst's model. The contribution of this paper lies in the formalization of these ideas

Relativistic calculations of the lifetimes and hyperfine structure constants in 67^{67}Zn+^{+}

This work presents accurate {\it ab initio} determination of the magnetic dipole (M1) and electric quadrupole (E2) hyperfine structure constants for the ground and a few low-lying excited states in $^{67}$Zn$^{+}$, which is one of the interesting systems in fundamental physics. The coupled-cluster (CC) theory within the relativistic framework has been used here in this calculations. Long standing demands for a relativistic and highly correlated calculations like CC can be able to resolve the disagreements among the lifetime estimations reported previously for a few low-lying states of Zn$^{+}$. The role of different electron correlation effects in the determination of these quantities are discussed and their contributions are presented.Comment: 9 pages, 1 figure. submitted to J. Phys. B Fast Trac

Chaos and localization in the wavefunctions of complex atoms NdI, PmI and SmI

Wavefunctions of complex lanthanide atoms NdI, PmI and SmI, obtained via multi-configuration Dirac-Fock method, are analyzed for density of states in terms of partial densities, strength functions ($F_k(E)$), number of principal components ($\xi_2(E)$) and occupancies (\lan n_\alpha \ran^E) of single particle orbits using embedded Gaussian orthogonal ensemble of one plus two-body random matrix ensembles [EGOE(1+2)]. It is seen that density of states are in general multi-modal, $F_k(E)$'s exhibit variations as function of the basis states energy and $\xi_2(E)$'s show structures arising from localized states. The sources of these departures from EGOE(1+2) are investigated by examining the partial densities, correlations between $F_k(E)$, $\xi_2(E)$ and \lan n_\alpha \ran^E and also by studying the structure of the Hamiltonian matrices. These studies point out the operation of EGOE(1+2) but at the same time suggest that weak admixing between well separated configurations should be incorporated into EGOE(1+2) for more quantitative description of chaos and localization in NdI, PmI and SmI.Comment: There are 9 figure

Calculation of the two-photon decay rates of hydrogen-like ions by using B-polynomials

A new approach is laid out to investigate the two photon atomic transitions. It is based on application of the finite basis solutions constructed from the Bernstein Polynomial (B-Polynomial) sets. We show that such an approach provides a very promising route for the relativistic second- (and even higher-order) calculations since it allows for analytical evaluation of the involved matrices elements. In order to illustrate possible applications of the method and to verify its accuracy, detailed calculations are performed for the 2s_{1/2}-1s_{1/2} transition in neutral hydrogen and hydrogen-like ions, and are compared with the theoretical predictions based on the well-established B-spline-basis-set approach

Salsalate treatment improves glycemia without altering adipose tissue in nondiabetic obese hispanics.

ObjectiveSalsalate treatment has well-known effects on improving glycemia, and the objective of this study was to examine whether the mechanism of this effect was related to changes in adipose tissue.MethodsA randomized double-blind and placebo-controlled trial in obese Hispanics (18-35 years) was conducted. The intervention consisted of 4 g day(-1) of salsalate (n = 11) versus placebo (n = 13) for 4 weeks. Outcome measures included glycemia, adiposity, ectopic fat, and adipose tissue gene expression and inflammation.ResultsIn those receiving salsalate, plasma fasting glucose decreased by 3.4% (P < 0.01), free fatty acids decreased by 42.5% (P = 0.06), and adiponectin increased by 27.7% (P < 0.01). Salsalate increased insulin AUC by 38% (P = 0.01) and HOMA-B by 47.2% (P < 0.01) while estimates of insulin sensitivity/resistance were unaffected. These metabolic improvements occurred without changes in total, abdominal, visceral, or liver fat. Plasma markers of inflammation/immune activation were unchanged following salsalate. Salsalate had no effects on adipose tissue including adipocyte size, presence of crown-like structures, or gene expression of adipokines, immune cell markers, or cytokines downstream of NF-κB with the exception of downregulation of IL-1β (P < 0.01).ConclusionsFindings suggest that metabolic improvements in response to salsalate occurred without alterations in adiposity, ectopic fat, or adipose tissue gene expression and inflammation