Finite-momentum Bose-Einstein condensates in shaken 2D square optical lattices

We consider ultracold bosons in a 2D square optical lattice described by the Bose-Hubbard model. In addition, an external time-dependent sinusoidal force is applied to the system, which shakes the lattice along one of the diagonals. The effect of the shaking is to renormalize the nearest-neighbor hopping coefficients, which can be arbitrarily reduced, can vanish, or can even change sign, depending on the shaking parameter. It is therefore necessary to account for higher-order hopping terms, which are renormalized differently by the shaking, and introduce anisotropy into the problem. We show that the competition between these different hopping terms leads to finite-momentum condensates, with a momentum that may be tuned via the strength of the shaking. We calculate the boundaries between the Mott-insulator and the different superfluid phases, and present the time-of-flight images expected to be observed experimentally. Our results open up new possibilities for the realization of bosonic analogs of the FFLO phase describing inhomogeneous superconductivity.Comment: 7 pages, 7 figure

FGF-2/FGFR1 neurotrophic system expression level and its basal activation do not account for the age-dependent decline of precursor cell proliferation in the subventricular zone of rat brain.

It is largely accepted that neurogenesis in the adult brain decreases with age and reduced levels of local neurotrophic support is speculated to be a contributing factor. Among neurotrophic factors involved on neurogenesis, we focused our attention on the neurotrophic system fibroblast growth factor-2 (FGF-2) and its receptor FGFR1, a potent modulator of precursor cell proliferation. In the present work, we aimed to analyse if potential age-dependent changes of the FGF-2/FGFR1 neurotrophic system may give account for the age-dependent decline of precursor cell proliferation in the neurogenic region of the subventricular zone (SVZ) in the rat brain. Using in situ hybridization and western blotting procedures we examined FGF-2 and FGFR1 expression levels in the SVZ of 20-month-old rats as compared to young adult 3-month-old rats. The results showed that during aging the FGF-2 and its receptor expression levels, both as mRNA and protein, were unchanged in the SVZ. The levels of phosphorylated FGFR1 form did not show significant variations suggesting that also the level of receptor activation does not change during aging. No changes were also observed in the phosphorylation of two FGFR1 related proteins involved in intracellular signaling, the canonical extracellular signal-regulated kinase Erk1/2 and the phospholipase-C\u3b31. Additionally, we could show that also the proliferation rate of stem cells does not change during aging. Taken together, our results show that FGF-2/FGFR1 neurotrophic system expression level and its basal activation do not account for the age-dependent decline of precursor cell proliferation in the rat brain

Spectrally resolved observations of atmospheric emitted radiance in the H2O rotation band

This paper presents the project Earth Cooling by Water Vapor Radiation, an observational programme, which aims at developing a database of spectrally resolved far infrared observations, in atmospheric dry conditions, in order to validate radiative transfer models and test the quality of water vapor continuum and line parameters. The project provides the very first set of far-infrared spectral downwelling radiance measurements, in dry atmospheric conditions, which are complemented with Raman Lidar-derived temperature and water vapor profiles

Phase transitions in the Potts spin glass model

We have studied the Potts spin glass with 2-state Ising spins and s-state Potts variables using a cluster Monte Carlo dynamics. The model recovers the +- J Ising spin glass (SG) for s=1 and exhibits for all s a SG transition at T_{SG}(s) and a percolation transition at higher temperature T_p(s). We have shown that for all values of $s\neq 1$ at T_p(s) there is a thermodynamical transition in the universality class of a ferromagnetic s-state Potts model. The efficiency of the cluster dynamics is compared with that of standard spin flip dynamics.Comment: 8 pages, Latex, with 8 EPS fig

Reduction of mdx mouse muscle degeneration by low-intensity endurance exercise: a proteomic analysis in quadriceps muscle of exercised versus sedentary mdx mice

In our recent study was shown a significant recovery of damaged skeletal muscle of mice with x-linked muscular dystrophy (mdx) following low-intensity endurance exercise, probably by reducing the degeneration of dystrophic muscle. Consequently, in the present work we aimed to identify proteins involved in the observed reduction of degenerating fibers. To this end, we used proteomic analysis to evaluate changes in the protein profile of quadriceps dystrophic muscles of exercised versus sedentary mdx mice. Four protein spots were found to be significantly changed and were identified as three isoforms of Carbonic anhydrase 3 (CA3) and superoxide dismutase [Cu-Zn] (SODC). Protein levels of CA3 isoforms were significantly up-regulated in quadriceps of sedentary mdx mice and were completely restored to wild type mice values, both sedentary and exercised, in quadriceps of exercised mdx mice. Protein levels of SODC were down-regulated in quadriceps of sedentary mdx mice and were significantly restored to wild type mice values, both sedentary and exercised, in quadriceps of exercised mdx mice. Western blot data were in agreement with those obtained using proteomic analysis and revealed the presence of one more CA3 isoform that was significantly changed. Based on data found in the present study, it seems that low-intensity endurance exercise may in part contribute to reduce cell degeneration process in mdx muscles, by counteracting oxidative stress

A Concerted Investigation For Metal/Semiconductor Nanointerface : Interlayer Charge Transfer At Ag/TiO2

In the field of hybrid materials, suitably designed nanoheterojunctions enhance synergistic functionalities and allow to obtain \u201cbrave new materials\u201d with physicochemical properties that are not simply the addition of the precursors\u2019 ones, but are completely new, different, and sometimes unexpected. For these reasons, the use of them has paved the way toward promising applications in many fields, such as electrocatalysis, photocatalysis, electroanalysis, and environmental chemistry, impacting on the everyday life [1]. However, research on such systems is most often dominated by trial and error procedures, while a deep atomistic understanding of the phenomena inside the junction region driving appropriate design of the final device is missing. Here, a concerted theoretical and electrochemical investigation is proposed to gain insights into the important class of heterojunctions made by metal-semiconductor interfaces. The presented case of study is the silver/anatase hybrid nanocomposite, a very promising material for advanced sensing applications [2]. Considering that in most cases titania semiconductors are useless in electroanalysis and silver is subject to fouling and oxidation/passivation, such broad outcomes were totally unexpected. Specifically, Ag/TiO2 interfase provided the first photorenewable sensor device, pushing the limits in terms of accuracy, sensitivity, detection limits, and photoactivity [3]. Despite the ongoing research, a quantitative and comprehensive understanding of the physics behind this nanocomposite is still missing, thus preventing its full exploitation and the extension of the same paradigm to other systems and devices. In particular, cyclic voltammetry and electrochemical impedance spectroscopy are used in combination with periodic plane-wave DFT calculations, giving comparable qualitative, but also quantitative results. We measure the exceptional electrochemical virtues of the Ag/TiO2 junction in terms of current densities and reproducibility, providing their explanation at the atomic-scale level and demonstrating how and why silver acts as a positive electrode [4]. We theoretically estimate the overall amount of electron transfer toward the semiconductor side of the interface at equilibrium and suitably designed electrochemical experiments strictly agree with the theoretical charge transfer estimates. Moreover, photoelectrochemical measurements and theoretical predictions show the unique permanent charge separation occurring in the device, possible because of the synergy of Ag and TiO2, which exploits in a favorable band alignment, in a smaller electron\u2013hole recombination rate and in a reduced carrier mobility when electrons cross the metal\u2013semiconductor interface. Finally, the hybrid material is proven to be extremely robust against aging, showing complete regeneration, even after one year [4]. [1] A.V. Emeline, V.N. Kuznetsov, V.K. Ryabchuk, N. Serpone, Environ. Sci. Pollut. Res. 19 (2012) 3666\u20133675. [2] G. Soliveri, V. Pifferi, G. Panzarasa, S. Ardizzone, G. Cappelletti, D. Meroni, K. Sparnacci, L. Falciola, Analyst 140 (2015) 1486\u20131494. [3] V. Pifferi, G. Soliveri, G. Panzarasa, G. Cappelletti, D. Meroni, L. Falciola, Anal. Bioanal. Chem. 408 (2016) 7339\u20137349. [4] G. Di Liberto, V. Pifferi, L. Lo Presti, M. Ceotto, and L. Falciola, J. Phys. Chem. Lett. 8 (2017) 5372\u20135377

Beneficial role of exercise in the modulation of mdx muscle plastic remodeling and oxidative stress

Duchenne muscular dystrophy (DMD) is an X-linked recessive progressive lethal disorder caused by the lack of dystrophin, which determines myofibers mechanical instability, oxidative stress, inflammation, and susceptibility to contraction-induced injuries. Unfortunately, at present, there is no efficient therapy for DMD. Beyond several promising gene-and stem cells-based strategies under investigation, physical activity may represent a valid noninvasive therapeutic approach to slow down the progression of the pathology. However, ethical issues, the limited number of studies in humans and the lack of consistency of the investigated training interventions generate loss of consensus regarding their efficacy, leaving exercise prescription still questionable. By an accurate analysis of data about the effects of different protocol of exercise on muscles of mdx mice, the most widely-used pre-clinical model for DMD research, we found that low intensity exercise, especially in the form of low speed treadmill running, likely represents the most suitable exercise modality associated to beneficial effects on mdx muscle. This protocol of training reduces muscle oxidative stress, inflammation, and fibrosis process, and enhances muscle functionality, muscle regeneration, and hypertrophy. These conclusions can guide the design of appropriate studies on human, thereby providing new insights to translational therapeutic application of exercise to DMD patients