In this work, we study gravity duals of conformal field theories with boundaries-known as AdS/BCFT correspondence, put forward by Takayanagi Phys. Rev. Lett. 107, 101602 (2011)-within a scalar-tensor ...theory, as proposed by Horndeski in 4D Int. J. Theor. Phys. 10, 363 (1974). We consider the case of 3D gravity dual to 2D BCFT, take a Gibbons-Hawking surface term modified by Horndeski's theory, and find the corresponding 3D (Bañados-Teitelboim-Zanelli) black hole solutions. We analyze the effects of Horndeski gravity on the profile of the extra boundary for the black hole by using an approximate analytic solution. Performing a holographic renormalization, we calculate the free energy and obtain the total entropy and corresponding area, as well as the boundary entropy for the black hole. In particular, the boundary entropy found here can be seen as an extension of the one proposed by Takayanagi. From the free energy, we perform a systematic study of the 3D black hole thermodynamics and present, among our results, an indication of the restoration of conformal symmetry for high temperatures. Finally, we present a study on the influence of Horndeski gravity on the Hawking-Page phase transition where we can see the stable and unstable phases throughout the plane of free energy versus temperature.
This work investigates the influence of a probe string on a complexity of braneworld according to the CA (Complexity equals action) conjecture within the Horndeski gravity. In the current study, it ...is considered that scalar fields that source Horndeski gravity have a spatial dependence. In addition, our system contains a particle moving on the boundary, which corresponds to the insertion of a fundamental string in the higher dimensional bulk. Such an effect is given by the Nambu‐Goto term, that also incorporates the time‐dependence and evolution in our system. Both warp factor, scalar field and superpotential values are derived numerically assuming appropriate initial conditions and the growth rate of holographic complexity is analysed within the so‐called Wheeler‐De Witt (WDW) patch with null‐like hypersurfaces present.
This work investigates the influence of a probe string on a complexity of braneworld according to the CA (Complexity equals action) conjecture within the Horndeski gravity. In the current study, it is considered that scalar fields that source Horndeski gravity have a spatial dependence. In addition, the system used contains a particle moving on the boundary, which corresponds to the insertion of a fundamental string in the higher dimensional bulk. Such an effect is given by the Nambu‐Goto term, that also incorporates the time‐dependence and evolution in our system. Both warp factor, scalar field and superpotential values are derived numerically assuming appropriate initial conditions and the growth rate of holographic complexity is analysed within the so‐called Wheeler‐De Witt (WDW) patch with null‐like hypersurfaces present.
Jupiter's aurorae are produced in its upper atmosphere when incoming high-energy electrons precipitate along the planet's magnetic field lines. A northern and a southern main auroral oval are ...visible, surrounded by small emission features associated with the Galilean moons. We present infrared observations, obtained with the Juno spacecraft, showing that in the case of Io, this emission exhibits a swirling pattern that is similar in appearance to a von Kármán vortex street. Well downstream of the main auroral spots the extended tail is split in two. Both of Ganymede's footprints also appear as a pair of emission features, which may provide a remote measure of Ganymede's magnetosphere. These features suggest that magnetohydrodynamic interaction between Jupiter and its moon is more complex than previously anticipated.
The continued contamination of water sources by pesticides is a problem that involves the life of aquatic organisms and human health, especially in countries whose economy is based on agriculture. ...The need to know the quality of drinking water under these circumstances is a priority for the public health of any community. Passive sampling methods allow the determination of long-term environmental pollutants through a single sample collection, reducing time and cost of analyses. One advantage of passive sampling is that it is possible to calculate a time-weighted average (TWA) concentration value or an equilibrium concentration value, depending on the type of device used and the exposure time. Passive sampling techniques using carbon nanomaterials (CNMs) have a high potential for pesticide sampling in aquatic systems. A device for passive sampling manufactured with CNMs in a microextraction system and recyclable materials was calibrated in laboratory exposure conditions over 15 days. The calibration results showed linear accumulation periods between 5 and 10 days. Sampling rates were between 0.014 and 0.146 mL day
−1
. The sampler was field-tested in the San Francisco river basin in the state of Minas Gerais in Brazil for 7 days. This research allowed for the detection and calculation of TWA concentrations for organochlorine pesticides such as α-HCH, 4,4-DDE, and 4,4-DD in water sources. The manufactured device demonstrated greater sensitivity than the grab sampling processes for the detection of pesticides. The performed passive sampling system using gas chromatography/mass spectrometry (GC/MS) technique allowed for the collection, detection, identification, and quantification of 26 pesticides.
Graphical abstract
The general solutions of Horndeski‐like gravity that can interpolate between the de Sitter and anti‐de Sitter regimes are presented. In particular, the first‐order formalism with two scalar fields is ...developed, and considering a black hole ansatz with flat slicing, three different cases, namely exponential, vacuum, and smooth superpotential solutions, with no Minkowski extrema are investigated. Furthermore, these solutions show that a Renormalization Group flow is established, and a turnaround in the warp factor is obtained, where the transition is bounded by the area low. The ideal regimes to trap gravity, which are constructed using the holographic function, which provides stable and unstable regimes to localize gravity are discussed. Finally, it is shown that no ghost appear and that the matter sector that violates the c$c$‐theorem is physical.
The general solutions of Horndeski‐like gravity that can interpolate between the de Sitter and anti‐de Sitter regimes are presented. In particular, the first‐order formalism with two scalar fields is developed, and considering a black hole ansatz with flat slicing, three different cases, namely exponential, vacuum, and smooth superpotential solutions, with no Minkowski extrema are investigated. Furthermore, these solutions show that a Renormalization Group flow is established, and a turnaround in the warp factor is obtained, where the transition is bounded by the area low. The ideal regimes to trap gravity, which are constructed using the holographic function, which provides stable and unstable regimes to localize gravity are discussed. Finally, it is shown that no ghost appear and that the matter sector that violates the c‐theorem is physical.
Background
Beta‐alanine (BA) supplementation increases muscle carnosine, an abundant endogenous antioxidant and pH buffer in skeletal muscle. Carnosine loading promotes exercise capacity in healthy ...older adults. As patients with chronic obstructive pulmonary disease (COPD) suffer from elevated exercise‐induced muscle oxidative/carbonyl stress and acidosis, and from reduced muscle carnosine stores, it was investigated whether BA supplementation augments muscle carnosine and induces beneficial changes in exercise capacity, quadriceps function, and muscle oxidative/carbonyl stress in patients with COPD.
Methods
In this double‐blind, randomized, placebo (PL)‐controlled trial (clinicaltrials.gov identifier: NCT02770417), 40 patients (75% male) with COPD (mean ± standard deviation: age 65 ± 6 years; FEV1% predicted 55 ± 14%) were assigned to 12 weeks oral BA or PL supplementation (3.2 g/day). The primary outcome, i.e. muscle carnosine, was quantified from m. vastus lateralis biopsies obtained before and after intervention. Co‐primary outcomes, i.e. incremental and constant work rate cycle capacity, were also assessed. Linear mixed model analyses were performed. Compliance with and side effects of supplement intake and secondary outcomes (quadriceps strength and endurance, and muscle oxidative/carbonyl stress) were also assessed.
Results
Beta‐alanine supplementation increased muscle carnosine in comparison with PL in patients with COPD (mean difference 95% confidence interval; +2.82 1.49–4.14 mmol/kg wet weight; P < 0.001). Maximal incremental cycling capacity (VO2peak: +0.5 −0.7 to 1.7 mL/kg/min; P = 0.384, Wpeak: +5 −1 to 11 W; P = 0.103) and time to exhaustion on the constant work rate cycle test (+28 −179 to 236 s; P = 0.782) did not change significantly. Compliance with supplement intake was similar in BA (median (quartile 1–quartile 3); 100 (98–100)%) and PL (98 (96–100)%) (P = 0.294) groups, and patients did not report side effects possibly related to supplement intake. No change was observed in secondary outcomes.
Conclusions
Beta‐alanine supplementation is efficacious in augmenting muscle carnosine (+54% from mean baseline value) without side effects in patients with COPD in comparison with PL. However, accompanied beneficial changes in exercise capacity, quadriceps function, and muscle oxidative/carbonyl stress were not observed.
Recently, much attention has been devoted to better understand the internal modes of variability of the climate system. This is particularly important in mid-latitude regions like the North-Atlantic, ...which is characterized by a large natural variability and is intrinsically difficult to predict. A suitable framework for studying the modes of variability of the atmospheric circulation is to look for recurrent patterns, commonly referred to as Weather Regimes. Each regime is characterized by a specific large-scale atmospheric circulation pattern, thus influencing regional weather and extremes over Europe. The focus of the present paper is the study of the Euro-Atlantic wintertime Weather Regimes in the climate models participating to the PRIMAVERA project. We analyse here the set of coupled historical simulations (hist-1950), which have been performed both at standard and increased resolution, following the HighresMIP protocol. The models’ performance in reproducing the observed Weather Regimes is assessed in terms of different metrics, focussing on systematic biases and on the impact of resolution. We also analyse the connection of the Weather Regimes with the Jet Stream latitude and blocking frequency over the North-Atlantic sector. We find that—for most models—the regime patterns are better represented in the higher resolution version, for all regimes but the NAO-. On the other side, no clear impact of resolution is seen on the regime frequency of occurrence and persistence. Also, for most models, the regimes tend to be more tightly clustered in the increased resolution simulations, more closely resembling the observed ones. However, the horizontal resolution is not the only factor determining the model performance, and we find some evidence that biases in the SSTs and mean geopotential field might also play a role.
We develop and analyze a concurrent framework for coupling peridynamics and the corresponding classical elasticity theory, with applications to the numerical simulations of damage problems. In this ...framework, the peridynamic model and the elastic model are solved separately and coupled with a partitioned approach. In the region where material failure is expected to initiate, we employ the peridynamic theory. In the rest of the problem domain, the material is modeled by the classical elasticity theory. On the peridynamic–classical theory interface, there is a transition region where the two subdomains overlap. The two solvers communicate by exchanging proper boundary conditions at the peridynamic–classical theory interface, which enables a modular software implementation. We analyze different coupling strategies on a 1D simplified problem and obtain expressions for the optimal reduction factor (convergence rate index). The selection of optimal coupling parameters is verified with numerical experiments, where we demonstrate that the optimal Robin coefficient from 1D simplified problem analysis can be extrapolated to more complicated problems, including cases with damage. Both the analysis and the numerical results suggest that the optimal Robin boundary condition on the classical theory side combined with a Dirichlet boundary condition with Aitken relaxation rule on the peridynamic side would be the most robust choice. Comparing with the commonly employed Dirichlet interface conditions, the optimal Robin boundary condition together with Aitken relaxation accelerates the coupling convergence rate by 10 times. With the developed optimal coupling strategy, we also numerically demonstrate the coupling framework’s asymptotic convergence to the local solution and its capability to capture crack initiation and growth in 2D problems.
Diabetes mellitus (DM) encompasses a multitude of secondary disorders, including heart disease. One of the most frequent and potentially life threatening disorders of DM-induced heart disease is ...ventricular tachycardia (VT). Here we show that toll-like receptor 2 (TLR2) and NLRP3 inflammasome activation in cardiac macrophages mediate the production of IL-1β in DM mice. IL-1β causes prolongation of the action potential duration, induces a decrease in potassium current and an increase in calcium sparks in cardiomyocytes, which are changes that underlie arrhythmia propensity. IL-1β-induced spontaneous contractile events are associated with CaMKII oxidation and phosphorylation. We further show that DM-induced arrhythmias can be successfully treated by inhibiting the IL-1β axis with either IL-1 receptor antagonist or by inhibiting the NLRP3 inflammasome. Our results establish IL-1β as an inflammatory connection between metabolic dysfunction and arrhythmias in DM.
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