Use of Green's functions in the numerical solution of two-point boundary value problems Final report, 1 Apr. 1970 - 31 Mar. 1971

Green function in solving linear and nonlinear second order ordinary differential equations including examples in finding rendezvous and periodic orbits of restricted three body syste

The application of a numerical integration procedure developed by erwin fehlberg to the restricted problem of three bodies

Application of numerical integration procedures to restricted three-body proble

Methods of fitting multivariant functional models in the area of large computer exploita- tion final report, 23 may 1963 - 23 jul. 1965

Methods of fitting multivariant functional models in area of large computer exploitatio

Composite Polarons in Ferromagnetic Narrow-band Metallic Manganese Oxides

A new mechanism is proposed to explain the colossal magnetoresistance and related phenomena. Moving electrons accompanied by Jahn-Teller phonon and spin-wave clouds may form composite polarons in ferromagnetic narrow-band manganites. The ground-state and finite-temperature properties of such composite polarons are studied in the present paper. By using a variational method, it is shown that the energy of the system at zero temperature decreases with the formation of composite polaron; the energy spectrum and effective mass of the composite polaron at finite temperature is found to be strongly renormalized by the temperature and the magnetic field. It is suggested that the composite polaron contribute significantly to the transport and the thermodynamic properties in ferromagnetic narrow-band metallic manganese oxides.Comment: Latex, no figur

Surface and electronic structure of MOCVD-grown Ga(0.92)In(0.08)N investigated by UV and X-ray photoelectron spectroscopies

The surface and electronic structure of MOCVD-grown layers of Ga(0.92)In(0.08)N have been investigated by means of photoemission. An additional feature at the valence band edge, which can be ascribed to the presence of In in the layer, has been revealed. A clean (0001)-(1x1) surface was prepared by argon ion sputtering and annealing. Stability of chemical composition of the investigated surface subjected to similar ion etching was proven by means of X-ray photoemission spectroscopy.Comment: 13 pages, 6 figure

Microscopic modelling of doped manganites

Colossal magneto-resistance manganites are characterised by a complex interplay of charge, spin, orbital and lattice degrees of freedom. Formulating microscopic models for these compounds aims at meeting to conflicting objectives: sufficient simplification without excessive restrictions on the phase space. We give a detailed introduction to the electronic structure of manganites and derive a microscopic model for their low energy physics. Focussing on short range electron-lattice and spin-orbital correlations we supplement the modelling with numerical simulations.Comment: 20 pages, 10 figs, accepted for publ. in New J. Phys., Focus issue on Orbital Physic

Live to cheat another day: bacterial dormancy facilitates the social exploitation of beta-lactamases

The breakdown of antibiotics by β-lactamases may be cooperative, since resistant cells can detoxify their environment and facilitate the growth of susceptible neighbours. However, previous studies of this phenomenon have used artificial bacterial vectors or engineered bacteria to increase the secretion of β-lactamases from cells. Here, we investigated whether a broad-spectrum β-lactamase gene carried by a naturally occurring plasmid (pCT) is cooperative under a range of conditions. In ordinary batch culture on solid media, there was little or no evidence that resistant bacteria could protect susceptible cells from ampicillin, although resistant colonies could locally detoxify this growth medium. However, when susceptible cells were inoculated at high densities, late-appearing phenotypically susceptible bacteria grew in the vicinity of resistant colonies. We infer that persisters, cells that have survived antibiotics by undergoing a period of dormancy, founded these satellite colonies. The number of persister colonies was positively correlated with the density of resistant colonies and increased as antibiotic concentrations decreased. We argue that detoxification can be cooperative under a limited range of conditions: if the toxins are bacteriostatic rather than bacteridical; or if susceptible cells invade communities after resistant bacteria; or if dormancy allows susceptible cells to avoid bactericides. Resistance and tolerance were previously thought to be independent solutions for surviving antibiotics. Here, we show that these are interacting strategies: the presence of bacteria adopting one solution can have substantial effects on the fitness of their neighbours

Cell-specific transcriptional control of mitochondrial metabolism by TIF1γ drives erythropoiesis.

Transcription and metabolism both influence cell function, but dedicated transcriptional control of metabolic pathways that regulate cell fate has rarely been defined. We discovered, using a chemical suppressor screen, that inhibition of the pyrimidine biosynthesis enzyme dihydroorotate dehydrogenase (DHODH) rescues erythroid differentiation in bloodless zebrafish moonshine (mon) mutant embryos defective for transcriptional intermediary factor 1 gamma (tif1γ). This rescue depends on the functional link of DHODH to mitochondrial respiration. The transcription elongation factor TIF1γ directly controls coenzyme Q (CoQ) synthesis gene expression. Upon tif1γ loss, CoQ levels are reduced, and a high succinate/α-ketoglutarate ratio leads to increased histone methylation. A CoQ analog rescues mon’s bloodless phenotype. These results demonstrate that mitochondrial metabolism is a key output of a lineage transcription factor that drives cell fate decisions in the early blood lineage

Is poetry therapy an appropriate intervention for clients recovering from anorexia? A critical review of the literature and client report

© 2017 Informa UK Limited, trading as Taylor & Francis Group. Poetry therapy is an arts-based psychotherapeutic intervention, often delivered in groups. This paper argues that the process and benefits of poetry therapy may be particularly suited to clients recovering from anorexia, as an adjunct to other treatments. Poetry therapy and its history are described briefly, and the relevance of poetry therapy for clients recovering from anorexia is outlined. After one client contributes her experience of this treatment for illustration, the paper offers a review of the evidence base for poetry therapy for eating disorders, and argues that, while research is limited, further research is warranted. Finally, a description of one form of clinical application is offered, to enable replication