Impact of pions on binary neutron star mergers

We study the impact of pions in simulations of neutron star mergers and explore the impact on gravitational-wave observables. We model charged and neutral pions as a non-interacting Boson gas with a chosen, constant effective mass. We add the contributions of pions, which can occur as a condensate or as a thermal population, to existing temperature and composition dependent equations of state. Compared to the models without pions, the presence of a pion condensate decreases the characteristic properties of cold, non-rotating neutron stars such as the maximum mass, the radius and the tidal deformability. We conduct relativistic hydrodynamical simulations of neutron star mergers for these modified equations of state models and compare to the original models, which ignore pions. Generally, the inclusion of pions leads to a softening of the equation of state, which is more pronounced for smaller effective pion masses. We find a shift of the dominant postmerger gravitational-wave frequency by up to 150~Hz to higher frequencies and a reduction of the threshold binary mass for prompt black-hole formation by up to 0.07~$M_\odot$. We evaluate empirical relations between the threshold mass or the dominant postmerger gravitational-wave frequency and stellar parameters of nonrotating neutron stars. These relations are constructed to extract these stellar properties from merger observations and are built based on large sets of equation of state models which do not include pions. Comparing to our calculations with pions, we find that these empirical relations remain valid to good accuracy, which justifies their use although they neglect a possible impact of pions. We also address the mass ejection by neutron star mergers and observe a moderate enhancement of the ejecta mass by a few ten per cent. (abridged)Comment: 27 pages, 24 figures, accepted for publication in Phys. Rev.

2-Deoxy-D-glucose couples mitochondrial DNA replication with mitochondrial fitness and promotes the selection of wild-type over mutant mitochondrial DNA

Pathological variants of human mitochondrial DNA (mtDNA) typically co-exist with wild-type molecules, but the factors driving the selection of each are not understood. Because mitochondrial fitness does not favour the propagation of functional mtDNAs in disease states, we sought to create conditions where it would be advantageous. Glucose and glutamine consumption are increased in mtDNA dysfunction, and so we targeted the use of both in cells carrying the pathogenic m.3243A>G variant with 2-Deoxy-D-glucose (2DG), or the related 5-thioglucose. Here, we show that both compounds selected wild-type over mutant mtDNA, restoring mtDNA expression and respiration. Mechanistically, 2DG selectively inhibits the replication of mutant mtDNA; and glutamine is the key target metabolite, as its withdrawal, too, suppresses mtDNA synthesis in mutant cells. Additionally, by restricting glucose utilization, 2DG supports functional mtDNAs, as glucose-fuelled respiration is critical for mtDNA replication in control cells, when glucose and glutamine are scarce. Hence, we demonstrate that mitochondrial fitness dictates metabolite preference for mtDNA replication; consequently, interventions that restrict metabolite availability can suppress pathological mtDNAs, by coupling mitochondrial fitness and replication

The impact of anisotropy on ITER scenarios

We report on the impact of anisotropy to tokamak plasma configuration and stability. Our focus is on analysis of the impact of anisotropy on ITER pre-fusion power operation 5 MA, B = 1.8 T ICRH scenarios. To model ITER scenarios remapping tools are developed to distinguish the impact of pressure anisotropy from the change in magnetic geometry caused by an anisotropy-modified current profile. The remappings iterate the anisotropy-modified current-density profile to produce the sameqprofile with matched thermal energy. The analysis is a step toward equilibria that are kinetically self-consistent for a prescribed scenario. We find characteristic detachment of flux surfaces from pressure surfaces and an outboard (inboard) shift of peak density for T-parallel to > T-perpendicular to (T-parallel to < T-perpendicular to). Differences in the poloidal current profile are evident, albeit not as pronounced as for the spherical tokamak. We find that the incompressional continuum is largely unchanged in the presence of anisotropy and the mode structure of gap modes is largely unchanged. The compressional branch however exhibits significant differences in the continuum. We report on the implication of these modifications

Surfactantes reativos não-iônicos em polimerização em emulsão de látices de acetato de vinila - vinil neodecanoato: influência nas propriedades de barreira à água Nonionic reactive surfactants in emulsion polymerization of vinyl acetate - vinyl neodecanoate latexes: influence on the water barrier properties

A indústria de tintas é grande consumidora de látex obtido por polimerização em emulsão. Os surfactantes, essenciais à estabilidade do látex, exercem papel fundamental na produção e na aplicação destes polímeros. Contudo, podem também produzir efeitos adversos nas propriedades do produto, em razão de sua adsorção física às partículas de polímero. Os surfactantes não ligados podem migrar através do filme para as interfaces, formando agregados que podem aumentar a sensibilidade à água, afetando desta forma as propriedades de barreira. Um caminho promissor para minimizar este efeito dos surfactantes convencionais tem sido o uso de surfactantes polimerizáveis, ou reativos, que estão covalentemente ligados ao polímero e, desta forma, não podem ser dessorvidos e migrarem durante a formação do filme. Neste trabalho foram preparados látices de acetato de vinila - vinil neodecanoato (VeoVa 10®), estabilizados com surfactantes não-iônicos convencionais e reativos, e avaliado o desempenho dos filmes obtidos a partir destes látices. Os resultados demonstraram que o uso de surfactantes não-iônicos polimerizáveis pode, sob determinadas condições, trazer ganhos para as propriedades de barreira.<br>The paint industry is a huge consumer of latex from emulsion polymerization. The surfactants, essential to the stability of the latex, play a crucial role in the production and application of emulsion polymers. However, they can also have adverse effects on product properties due to their physical adsorption on the polymer particles. The unbound surfactants can migrate through the film toward the interfaces forming aggregates which increase water sensitivity of the film, thus affecting its barrier properties. A promising way to reduce the negative effects of the conventional surfactants is to use polymerizable or reactive surfactants (surfmers) that are covalently linked to the polymer, which avoids its desorption and migration during the film formation. In this work vinyl acetate - vinyl neodecanoate (VeoVa 10®) latexes, stabilized with conventional and reactive nonionic surfactant, were prepared and the performance of these films was evaluated. It was noted that latexes stabilized with nonionic polymerizable surfactants can bring, under certain conditions, better barrier properties