Non-monotonic entanglement of physical EM field states in non-inertial frames

We develop a general technique to analyse the quantum effects of acceleration on realistic spatially-localised electromagnetic field states entangled in the polarization degree of freedom. We show that for this setting, quantum entanglement may build up as the acceleration increases, providing a clear signature of the quantum effects of relativistic acceleration.Comment: 5 pages, 3 figure

Population bound effects on bosonic correlations in non-inertial frames

We analyse the effect of bounding the occupation number of bosonic field modes on the correlations among all the different spatial-temporal regions in a setting in which we have a space-time with a horizon along with an inertial observer. We show that the entanglement between A (inertial observer) and R (uniformly accelerated observer) depends on the bound N, contrary to the fermionic case. Whether or not decoherence increases with N depends on the value of the acceleration a. Concerning the bipartition A-antiR (Alice with an observer in Rindler's region IV), we show that no entanglement is created whatever the value of N and a. Furthermore, AR entanglement is very quickly lost for finite N and for infinite N. We will study in detail the mutual information conservation law found for bosons and fermions. By means of the boundary effects associated to N finiteness, we will show that for bosons this law stems from classical correlations while for fermions it has a quantum origin. Finally, we will present the strong N dependence of the entanglement in R-antiR bipartition and compare the fermionic cases with their finite N bosonic analogs. We will also show the anti-intuitive dependence of this entanglement on statistics since more entanglement is created for bosons than for their fermion counterparts.Comment: revtex 4, 12 pages, 10 figures. Added Journal ref

Entanglement of arbitrary spin fields in non-inertial frames

We generalise the study of fermionic and bosonic entanglement in non-inertial frames to fields of arbitrary spin and beyond the single mode approximation. After the general analysis we particularise for two interesting cases: entanglement between an inertial and an accelerated observer for massless fields of spin 1 (electromagnetic) and 3/2 (Rarita-Schwinger). We show that in the limit of infinite acceleration, no significant differences appear between the different spin fields for the states considered.Comment: 7 pages, 3 figures. Revtex 4.

Unveiling quantum entanglement degradation near a Schwarzschild black hole

We analyze the entanglement degradation provoked by the Hawking effect in a bipartite system Alice-Rob when Rob is in the proximities of a Schwarzschild black hole while Alice is free falling into it. We will obtain the limit in which the tools imported from the Unruh entanglement degradation phenomenon can be used properly, keeping control on the approximation. As a result, we will be able to determine the degree of entanglement as a function of the distance of Rob to the event horizon, the mass of the black hole, and the frequency of Rob's entangled modes. By means of this analysis we will show that all the interesting phenomena occur in the vicinity of the event horizon and that the presence of event horizons do not effectively degrade the entanglement when Rob is far off the black hole. The universality of the phenomenon is presented: There are not fundamental differences for different masses when working in the natural unit system adapted to each black hole. We also discuss some aspects of the localization of Alice and Rob states. All this study is done without using the single mode approximation.Comment: 16 pages, 10 figures, revtex4. Added Journal referenc

The interleukin-6 and noradrenaline mediated inflammation-stress feedback mechanism is dysregulated in metabolic syndrome: Effect of exercise

<p>Abstract</p> <p>Background</p> <p>Metabolic syndrome (MS) is a metabolic disorder associated with obesity, type-II diabetes, and "low grade inflammation", with the concomitant increased risk of cardiovascular events. Removal of the inflammatory mediator signals is a promising strategy to protect against insulin resistance, obesity, and other problems associated with MS such as cardiovascular disease. The aim of the present investigation was to determine the "inflammatory and stress status" in an experimental model of MS, and to evaluate the effect of a program of habitual exercise and the resulting training-induced adaptation to the effects of a single bout of acute exercise.</p> <p>Methods</p> <p>Obese Zucker rats (fa/fa) were used as the experimental model of MS, and lean Zucker rats (Fa/fa) were used for reference values. The habitual exercise (performed by the obese rats) consisted of treadmill running: 5 days/week for 14 weeks, at 35 cm/s for 35 min in the last month. The acute exercise consisted of a single session of 25-35 min at 35 cm/s. Circulating concentrations of IL-6 (a cytokine that regulates the inflammatory and metabolic responses), CRP (a systemic inflammatory marker), and corticosterone (CTC) (the main glucocorticoid in rats) were determined by ELISA, and that of noradrenaline (NA) was determined by HPLC. Glucose was determined by standard methods.</p> <p>Results</p> <p>The genetically obese animals showed higher circulating levels of glucose, IL-6, PCR, and NA compared with the control lean animals. The habitual exercise program increased the concentration of IL-6, PCR, NA, and glucose, but decreased that of CTC. Acute exercise increased IL-6, CRP, and NA in the sedentary obese animals, but not in the trained obese animals. CTC was increased after the acute exercise in the trained animals only.</p> <p>Conclusion</p> <p>Animals with MS present a dysregulation in the feedback mechanism between IL-6 and NA which can contribute to the systemic low-grade inflammation and/or hyperglycaemia of MS. An inappropriate exercise intensity can worsen this dysregulation, contributing to the metabolic, inflammatory, and stress disorders associated with MS. Habitual exercise (i.e., training) induces a positive adaptation in the response to acute exercise.</p

Conditional BDNF release under pathological conditions improves Huntington's disease pathology by delaying neuronal dysfunction

Background Brain-Derived Neurotrophic Factor (BDNF) is the main candidate for neuroprotective therapy for Huntington's disease (HD), but its conditional administration is one of its most challenging problems. Results Here we used transgenic mice that over-express BDNF under the control of the Glial Fibrillary Acidic Protein (GFAP) promoter (pGFAP-BDNF mice) to test whether up-regulation and release of BDNF, dependent on astrogliosis, could be protective in HD. Thus, we cross-mated pGFAP-BDNF mice with R6/2 mice to generate a double-mutant mouse with mutant huntingtin protein and with a conditional over-expression of BDNF, only under pathological conditions. In these R6/2:pGFAP-BDNF animals, the decrease in striatal BDNF levels induced by mutant huntingtin was prevented in comparison to R6/2 animals at 12 weeks of age. The recovery of the neurotrophin levels in R6/2:pGFAP-BDNF mice correlated with an improvement in several motor coordination tasks and with a significant delay in anxiety and clasping alterations. Therefore, we next examined a possible improvement in cortico-striatal connectivity in R62:pGFAP-BDNF mice. Interestingly, we found that the over-expression of BDNF prevented the decrease of cortico-striatal presynaptic (VGLUT1) and postsynaptic (PSD-95) markers in the R6/2:pGFAP-BDNF striatum. Electrophysiological studies also showed that basal synaptic transmission and synaptic fatigue both improved in R6/2:pGAP-BDNF mice. Conclusions These results indicate that the conditional administration of BDNF under the GFAP promoter could become a therapeutic strategy for HD due to its positive effects on synaptic plasticity

Y6 Organic Thin-Film Transistors with Electron Mobilities of 2.4 cm2 V−1 s−1 via Microstructural Tuning

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] There is a growing demand to attain organic materials with high electron mobility, μe, as current reliable reported values are significantly lower than those exhibited by their hole mobility counterparts. Here, it is shown that a well-known nonfullerene-acceptor commonly used in organic solar cells, that is, BTP-4F (aka Y6), enables solution-processed organic thin-film transistors (OTFT) with a μe as high as 2.4 cm2 V−1 s−1. This value is comparable to those of state-of-the-art n-type OTFTs, opening up a plethora of new possibilities for this class of materials in the field of organic electronics. Such efficient charge transport is linked to a readily achievable highly ordered crystalline phase, whose peculiar structural properties are thoroughly discussed. This work proves that structurally ordered nonfullerene acceptors can exhibit intrinsically high mobility and introduces a new approach in the quest of high μe organic materials, as well as new guidelines for future materials design.Ministerio de Ciencia e Innovación; PGC2018-094620-A-I00Xunta de Galicia; ED431F 2021/00

Quantum correlations through event horizons: Fermionic versus bosonic entanglement

We disclose the behaviour of quantum and classical correlations among all the different spatial-temporal regions of a space-time with an event horizon, comparing fermionic with bosonic fields. We show the emergence of conservation laws for entanglement and classical correlations, pointing out the crucial role that statistics plays in the information exchange (and more specifically, the entanglement tradeoff) across horizons. The results obtained here could shed new light on the problem of information behaviour in non-inertial frames and in the presence of horizons, giving a better insight about the black hole information paradox.Comment: 15 pages, 8 figures, revtex 4, title changed to match journal publication and Journal reference adde

Vanishing Geometric Discord in Non-Inertial Frames

We show that quantum field correlations in non-inertial frames are not as persistent as previously thought. We perform a simple calculation showing that the geometric discord, a measure of quantum correlations, does decay to zero in the infinite acceleration limit. This result is seen to be a natural and expected consequence of considering correlations in an infinite dimensional system, and it sheds doubt on the existence of useable quantum correlations in this regime. We contrast our results with previous research showing that the acceleration-induced degradation of quantum discord was not strong enough to extinguish discord in the large acceleration limit.Comment: 9 pages, revtex4, 2 figures. V2 Added journal reference and updated to published versio