A self-consistent approach to the Wigner-Seitz treatment of soliton matter

We propose a self-consistant approach to the treatment of nuclear matter as a crystal of solitons in the Wigner-Seitz approximation. Specifically, we use a Bloch-like boundary condition on the quarks at the edge of a spherical cell which allows the dispersion relation for a given radius to be calculated self-consistently along with the meson fields; in previous work some ansatz for the dispersion relation has always been an input. Results in all models are very sensitive to the form of the dispersion relation, so our approach represents a significant advance. We apply the method to both the Friedberg Lee model and the chiral quark-meson model of Birse and Banerjee. Only the latter shows short range repulsion; in the former the transition to a quark plasma occurs at unrealistically low densities.Comment: Revtex; 14 pages with 9 eps figure

Determination of the charge carrier compensation mechanism in Te-doped GaAs by scanning tunneling microscopy.

We identified the charge carrier compensation mechanism in Te-doped GaAs with atomically resolved scanning tunneling microscopy. Three types of defects were found: tellurium donors (Te-As), Ga vacancies (V-Ga), and Ga vacancy-donor complexes (V-Ga-Te-As). We show quantitatively that the compensation in Te-doped bulk GaAs is exclusively caused by vacancy-donor complexes in contrast to Si-doped GaAs. This is explained with the Fermi-level effect as the universal mechanism leading to Ga vacancy formation in n-doped GaAs, and a Coulomb interaction leading to the formation of the complexes. The quantification of the carrier compensation yields a -3e charge state of V-Ga in bulk GaAs. (C) 2003 American Institute of Physics

Interaction Of Electrons With Spin Waves In The Bulk And In Multilayers

The exchange interaction between electrons and magnetic spins is considerably enhanced near interfaces, in magnetic multilayers. As a result, a dc current can be used to generate spin oscillations. We review theory and experimental evidence. The s-d exchange interaction causes a rapid precession of itinerant conduction-electron spins s around the localized spins S of magnetic electrons. Because of the precession, the time-averaged interaction torque between s and S vanishes. An interface between a magnetic layer and a spacer causes a local coherence between the precession phases of differnt electrons, within 10 nm from the interface, and restores the torque. Also, a second magnetic layer with pinned S is used to prepare s in a specific direction. the current-induced drive torque of s on S in the active layer may be calculated from the spin current (Slonczewski) or from the spin imbalance Delta-mu (Berger). Spin current and Delta-mu are proportional to each other, and can arise from Fermi-surface translation, as well as from expansion/contraction.Comment: Invited paper at Seattle MMM01 Conference, Nov. 2001 (to appear in J. Appl. Phys.

Replacing gas boilers with heat pumps is the fastest way to cut German gas consumption

The supply security of fossil gas has been disrupted by the Russo-Ukrainian War. Decisions to relocate the production and transport of gas have become so urgent that new long-term contracts are imminent that undermine the Paris Climate Agreement. Here, we simulate how quickly the addition of renewable electricity and the installation of heat pumps can substitute enough gas to reduce supply risk, while taking a decisive step towards meeting the Paris Agreement. Our bottom-up modelling, using Germany as an example, shows technical pathways on how installing heat pumps is one of the fastest ways to reduce gas consumption, in addition to reducing the load hours of gas-fired power plants. With targeted efforts, maximally 60% of gas from the Russian Federation can be substituted by 2025 with heat pumps and grid expansions, and enough electricity will remain available that the phase-out of coal and the entry into e-mobility will still be practicable

Replacing gas boilers with heat pumps is the fastest way to cut German gas consumption

The supply security of fossil gas has been disrupted by the Russo-Ukrainian War. Decisions to relocate the production and transport of gas have become so urgent that new long-term contracts are imminent that undermine the Paris Climate Agreement. Here, we simulate how quickly the addition of renewable electricity and the installation of heat pumps can substitute enough gas to reduce supply risk, while taking a decisive step towards meeting the Paris Agreement. Our bottom-up modelling, using Germany as an example, shows technical pathways on how installing heat pumps is one of the fastest ways to reduce gas consumption, in addition to reducing the load hours of gas-fired power plants. With targeted efforts, maximally 60% of gas from the Russian Federation can be substituted by 2025 with heat pumps and grid expansions, and enough electricity will remain available that the phase-out of coal and the entry into e-mobility will still be practicable

The ρNN\rho NN coupling with direct coupling and loops

Starting from a gauge formalism of $\rho$ mesons, pions and baryons we evaluate the $\rho$ coupling to the nucleon, including the direct coupling provided by the Lagrangians, plus contributions from loops with the virtual pion cloud. We find a contribution to the magnetic $\rho$ coupling to the nucleon from pionic loops of the same size as the direct coupling, which is, however, still small compared to the empirical values. This finding goes in line with chiral formulations of the strong interaction of mesons at low energies where, unlike the scalar mesons which are mostly built of a pion (kaon) cloud, the $\rho$ meson stands as a genuine QCD state with intrinsic properties not tied to those of the pion cloud.Comment: 21 pages, 13 figure

Relationship between the gut microbiome and endometriosis and its role in pathogenesis, diagnosis, and treatment: a systematic review

Endometriosis is a chronic inflammatory disease affecting approximately 10% of women. It is defined as endometrial tissue outside of the uterus and produces a variety of symptoms including pelvic pain, dysmenorrhea, dyspareunia, and intermenstrual bleeding. Although several theories have been postulated regarding the pathogenesis of endometriosis, no theory has provided a complete explanation, therefore limiting our progress in diagnostic tools and management of endometriosis. Recently, much attention has been paid to the importance and role of the gut microbiome in endometriosis. As defined by Joshua Lederberg — microbiome is a set of the genome of microorganisms inhabiting a human body, including commensal, symbiotic and pathogenic microorganisms. The aim of this systematic review was to conduct a search in the Embase, Medline, and PubMed databases for literature from July 2013 to July 2023 regarding the relationship between the gut microbiome and endometriosis. 147 records were screened, of which 26 met the eligibility criteria, and 16 were included in this review. Our review concludes that patients with endometriosis show an altered gut microbiome, and that this has the potential to provide insight for pathogenesis, markers for diagnosis, as well as therapeutic options for treatment of endometriosis. Future research is necessary to confirm this and further investigate the relationship between the gut microbiome and endometriosis

Self-Organization, Layered Structure, and Aggregation Enhance Persistence of a Synthetic Biofilm Consortium

Microbial consortia constitute a majority of the earth’s biomass, but little is known about how these cooperating communities persist despite competition among community members. Theory suggests that non-random spatial structures contribute to the persistence of mixed communities; when particular structures form, they may provide associated community members with a growth advantage over unassociated members. If true, this has implications for the rise and persistence of multi-cellular organisms. However, this theory is difficult to study because we rarely observe initial instances of non-random physical structure in natural populations. Using two engineered strains of Escherichia coli that constitute a synthetic symbiotic microbial consortium, we fortuitously observed such spatial self-organization. This consortium forms a biofilm and, after several days, adopts a defined layered structure that is associated with two unexpected, measurable growth advantages. First, the consortium cannot successfully colonize a new, downstream environment until it selforganizes in the initial environment; in other words, the structure enhances the ability of the consortium to survive environmental disruptions. Second, when the layered structure forms in downstream environments the consortium accumulates significantly more biomass than it did in the initial environment; in other words, the structure enhances the global productivity of the consortium. We also observed that the layered structure only assembles in downstream environments that are colonized by aggregates from a previous, structured community. These results demonstrate roles for self-organization and aggregation in persistence of multi-cellular communities, and also illustrate a role for the techniques of synthetic biology in elucidating fundamental biological principles