On gaugino condensation in the effective theory

We analyze the gaugino condensation in the effective theory for N=1 SU(N) Supersymmetric QCD with $N_{f}$ flavors. It is known that taking the vacuum expectation value of the matter field to be infinite, we can show that gaugino condensation can occur. At such a limit we should consider only pure supersymmetric Yang-Mills theory. But when we include an interaction term of order $O(\frac{1}{v})$, the situation can change. We analyze the effect of this interaction term and examine the gaugino condensation in the low energy Yang-Mills theory by using the scheme of Nambu-Jona-Lasinio.Comment: 5 pages, Plain Late

A natural solution to the μ\mu-problem in dynamical supergravity model

The Higgs mixing term coefficient $\mu$ is calculated in the supersymmetric theory which possesses a non-anomalous $U(1)_{R}$ symmetry in the limit of global supersymmetry. In this model, supersymmetry is assumed to be broken by gaugino condensation in the hidden sector when the supergravity effects are turned on. The soft breaking terms in the visible sector and the $\mu$ term of order the weak scale are produced in a simple manner.Comment: 6 pages, Latex, accepted for publication in Phys.Rev.

Collapse to Black Holes in Brans-Dicke Theory: I. Horizon Boundary Conditions for Dynamical Spacetimes

We present a new numerical code that evolves a spherically symmetric configuration of collisionless matter in the Brans-Dicke theory of gravitation. In this theory the spacetime is dynamical even in spherical symmetry, where it can contain gravitational radiation. Our code is capable of accurately tracking collapse to a black hole in a dynamical spacetime arbitrarily far into the future, without encountering either coordinate pathologies or spacetime singularities. This is accomplished by truncating the spacetime at a spherical surface inside the apparent horizon, and subsequently solving the evolution and constraint equations only in the exterior region. We use our code to address a number of long-standing theoretical questions about collapse to black holes in Brans-Dicke theory.Comment: 46 pages including figures, uuencoded gz-compressed postscript, Submitted to Phys Rev

Femtosecond nonlinear ultrasonics in gold probed with ultrashort surface plasmons

Fundamental interactions induced by lattice vibrations on ultrafast time scales become increasingly important for modern nanoscience and technology. Experimental access to the physical properties of acoustic phonons in the THz frequency range and over the entire Brillouin zone is crucial for understanding electric and thermal transport in solids and their compounds. Here, we report on the generation and nonlinear propagation of giant (1 percent) acoustic strain pulses in hybrid gold/cobalt bilayer structures probed with ultrafast surface plasmon interferometry. This new technique allows for unambiguous characterization of arbitrary ultrafast acoustic transients. The giant acoustic pulses experience substantial nonlinear reshaping already after a propagation distance of 100 nm in a crystalline gold layer. Excellent agreement with the Korteveg-de Vries model points to future quantitative nonlinear femtosecond THz-ultrasonics at the nano-scale in metals at room temperature

Collapse to Black Holes in Brans-Dicke Theory: II. Comparison with General Relativity

We discuss a number of long-standing theoretical questions about collapse to black holes in the Brans-Dicke theory of gravitation. Using a new numerical code, we show that Oppenheimer-Snyder collapse in this theory produces black holes that are identical to those of general relativity in final equilibrium, but are quite different from those of general relativity during dynamical evolution. We find that there are epochs during which the apparent horizon of such a black hole passes {\it outside\/} the event horizon, and that the surface area of the event horizon {\it decreases\/} with time. This behavior is possible because theorems which prove otherwise assume $R_{ab}l^al^b \ge 0$ for all null vectors $l^a$. We show that dynamical spacetimes in Brans-Dicke theory can violate this inequality, even in vacuum, for any value of $\omega$.Comment: 24 pages including figures, uuencoded gz-compressed postscript, Submitted to Phys Rev

Inhibition of Y1 receptor signaling improves islet transplant outcome

Failure to secrete sufficient quantities of insulin is a pathological feature of type-1 and type-2 diabetes, and also reduces the success of islet cell transplantation. Here we demonstrate that Y1 receptor signaling inhibits insulin release in β-cells, and show that this can be pharmacologically exploited to boost insulin secretion. Transplanting islets with Y1 receptor deficiency accelerates the normalization of hyperglycemia in chemically induced diabetic recipient mice, which can also be achieved by short-term pharmacological blockade of Y1 receptors in transplanted mouse and human islets. Furthermore, treatment of non-obese diabetic mice with a Y1 receptor antagonist delays the onset of diabetes. Mechanistically, Y1 receptor signaling inhibits the production of cAMP in islets, which via CREB mediated pathways results in the down-regulation of several key enzymes in glycolysis and ATP production. Thus, manipulating Y1 receptor signaling in β-cells offers a unique therapeutic opportunity for correcting insulin deficiency as it occurs in the pathological state of type-1 diabetes as well as during islet transplantation.Islet transplantation is considered one of the potential treatments for T1DM but limited islet survival and their impaired function pose limitations to this approach. Here Loh et al. show that the Y1 receptor is expressed in β- cells and inhibition of its signalling, both genetic and pharmacological, improves mouse and human islet function.info:eu-repo/semantics/publishe

Illusions of general relativity in Brans-Dicke gravity

Contrary to common belief, the standard tenet of Brans-Dicke theory reducing to general relativity when omega tends to infinity is false if the trace of the matter energy-momentum tensor vanishes. The issue is clarified in a new approach using conformal transformations. The otherwise unaccountable limiting behavior of Brans-Dicke gravity is easily understood in terms of the conformal invariance of the theory when the sources of gravity have radiation-like properties. The rigorous computation of the asymptotic behavior of the Brans-Dicke scalar field is straightforward in this new approach.Comment: 16 pages, LaTeX, to appear in Physical Review

Using honey to heal diabetic foot ulcers

Diabetic ulcers seem to be arrested in the inflammatory/proliferative stage of the healing process, allowing infection and inflammation to preclude healing. Antibiotic-resistant bacteria have become a major cause of infections, including diabetic foot infections. It is proposed here that the modern developments of an ancient and traditional treatment for wounds, dressing them with honey, provide the solution to the problem of getting diabetic ulcers to move on from the arrested state of healing. Honeys selected to have a high level of antibacterial activity have been shown to be very effective against antibiotic-resistant strains of bacteria in laboratory and clinical studies. The potent anti-inflammatory action of honey is also likely to play an important part in overcoming the impediment to healing that inflammation causes in diabetic ulcers, as is the antioxidant activity of honey. The action of honey in promotion of tissue regeneration through stimulation of angiogenesis and the growth of fibroblasts and epithelial cells, and its insulin-mimetic effect, would also be of benefit in stimulating the healing of diabetic ulcers. The availability of honey-impregnated dressings which conveniently hold honey in place on ulcers has provided a means of rapidly debriding ulcers and removing the bacterial burden so that good healing rates can be achieved with neuropathic ulcers. With ischemic ulcers, where healing cannot occur because of lack of tissue viability, these honey dressings keep the ulcers clean and prevent infection occurring

Grape skin extracts from winemaking by-products as a source of trapping agents for reactive carbonyl species

BACKGROUND Clinical evidence supports the relationship between carbonyl stress and type II diabetes and its related pathologies. Methylglyoxal (MGO) is the major dicarbonyl compound involved in carbonyl stress. Efforts are therefore being made to find dietary compounds from natural sources that could exert an MGO trapping response. RESULTS The in vitro MGO trapping capacity of six red and seven white grape skin extracts (GSE) obtained from winemaking by-products was investigated. Methanolic GSE exhibited a promising MGO trapping capacity that was higher in red GSE (IC50 2.8 mg mL−1) when compared with white GSE (IC50 3.2 mg mL−1). The trapping ability for red GSE correlated significantly with total phenolic content and antioxidant capacity. However, no correlations were observed for white GSE, which suggests that other compounds were involved in the trapping activity. CONCLUSION GSE may be considered a natural source of carbonyl stress inhibitors, thus opening up its possible utilization as a nutraceutical ingredient. Further investigations are required to understand the mechanism involved in the carbonyl trapping ability of red and white grape skin samples and their relationship with glycation. © 2015 Society of Chemical Industry.PSC Sri Harsha would like to thank the University of Milan for providing additional funding through the ERASMUS student network program. This work was partly funded by projects CSIC-201370E027, AGER (project number 2010–2222) and S2013/ABI-3028-AVANSECAL.Peer reviewe