Black-Hole Solutions with Scalar Hair in Einstein-Scalar-Gauss-Bonnet Theories

In the context of the Einstein-scalar-Gauss-Bonnet theory, with a general coupling function between the scalar field and the quadratic Gauss-Bonnet term, we investigate the existence of regular black-hole solutions with scalar hair. Based on a previous theoretical analysis, that studied the evasion of the old and novel no-hair theorems, we consider a variety of forms for the coupling function (exponential, even and odd polynomial, inverse polynomial, and logarithmic) that, in conjunction with the profile of the scalar field, satisfy a basic constraint. Our numerical analysis then always leads to families of regular, asymptotically-flat black-hole solutions with non-trivial scalar hair. The solution for the scalar field and the profile of the corresponding energy-momentum tensor, depending on the value of the coupling constant, may exhibit a non-monotonic behaviour, an unusual feature that highlights the limitations of the existing no-hair theorems. We also determine and study in detail the scalar charge, horizon area and entropy of our solutions.Comment: PdfLatex file, 29 Pages, 18 figures, the analysis was extended to study the scalar charge, horizon area and entropy of our solutions, comments added, typos corrected, version to appear in Physical Review

Secure & trusted communication in emergency situations

In this paper we propose SETS, a protocol with main aim to provide secure and private communication during emergency situations. SETS achieves security of the exchanged information, attack resilience and user’s privacy. In addition, SETS can be easily adapted for mobile devices, since field experimental results show the effectiveness of the protocol on actual smart-phone platforms

Variation in the molecular weight of Photobacterium damselae subsp. piscicida antigens when cultured under different conditions in vitro

The antigenicity of Photobacterium damselae (Ph. d.) subsp. piscicida, cultured in four different growth media [tryptone soya broth (TSB), glucose-rich medium (GRM), iron-depleted TSB (TSB + IR-), and iron-depleted GRM (GRM + IR-)] was compared by enzyme-linked immunosorbent assay (ELISA) and Western blot analysis using sera obtained from sea bass (Dicentrarchus labrax) raised against live or heat-killed Ph. d. subsp. piscicida. The antigenic expression of Ph. d. subsp. piscicida was found to differ depending on the culture medium used. A significantly higher antibody response was obtained with iron-depleted bacteria by ELISA compared with non-iron depleted bacteria obtained from the sera of sea bass raised against live Ph. d. subsp. piscicida. The sera from sea bass raised against live bacteria showed a band at 22 kDa in bacteria cultured in TSB + IR- or GRM+ IR- when bacteria that had been freshly isolated from fish were used for the screening, while bands at 24 and 47 kDa were observed with bacteria cultured in TSB or GRM. When bacteria were passaged several times on tryptic soya agar prior to culturing in the four different media, only bands at 24 and 47 kDa were recognized, regardless of the medium used to culture the bacteria. It would appear that the molecular weight of Ph. d. subsp. piscicida antigens change in the presence of iron restriction, and sera from sea bass infected with live bacteria are able to detect epitopes on the antigens after this shift in molecular weight

The divider set of explicit parametric geometry

In this paper we describe a novel concept for classification of complex parametric geometry based on the concept of the Divider Set. The Divider Set is an alternative concept to maximal disks, Voronoi sets and cut loci. The Divider Set is based on a formal definition relating to topology and differential geometry. In this paper firstly we discuss the formal definition of the Divider Set for complex 3-dimensional geometry. This is then followed by the introduction of a computationally feasible algorithm for computing the Divider Set for geometry which can be defined in explicit parametric form. Thus, an explicit solution form taking advantage of the special form of the parametric geometry is presented. We also show how the Divider Set can be computed for various complex parametric geometry by means of illustrating our concept through a number of example

In vivo morphological and antigenic characteristics of Photobacterium damselae subsp. piscicida

The present study was conducted to examine the morphology and antigenicity of Photobacterium damselae subsp. piscicida by culturing the bacterium in vivo in the peritoneal cavity of sea bass (Dicentrarchus labrax) within dialysis bags with either a low molecular weight (LMW) cut-off of 25 kDa or a high molecular weight (HMW) cut-off of 300 kDa. Differences were observed in the growth rate between the bacteria cultured in vivo or in vitro. Bacteria cultured in vivo were smaller and produced a capsular layer, which was more prominent in bacteria cultured in the HMW bag. Antigenicity was examined by Western blot analysis using sera from sea bass injected with live Ph. d. subsp. piscicida. The sera recognised bands at 45 and 20 kDa in bacteria cultured in vivo in the LMW bag. Bacteria cultured in vivo in the HMW bag did not express the 45 kDa band when whole cell extracts were examined, although the antigen was present in their extracellular products. In addition, these bacteria had a band at 18 kDa rather than 20 kDa. Differences in glycoprotein were also evident between bacteria cultured in vitro and in vivo. Bacteria cultured in vitro in LMW and HMW bags displayed a single 26 kDa band. Bacteria cultured in the LMW bag in vivo displayed bands at 26 and 27 kDa, while bacteria cultured in vivo in the HMW bag possessed only the 27 kDa band. These bands may represent sialic acid. The significance of the changes observed in the bacterium's structure and antigenicity when cultured in vivo is discussed

Semiconductor Optical Amplifier (SOA)–Based Amplification of Intensity-Modulated Optical Pulses — Deterministic Timing Jitter and Pulse Peak Power Equalization Analysis

During the last few years, large-scale efforts towards realizing high-photonic integration densities have put SOAs in the spotlight once again. Hence, the need to develop a complete framework for SOA-induced signal distortion to accurately evaluate a system’s performance has now become evident. To cope with this demand, we present a detailed theoretical and experimental investigation of the deterministic timing jitter and the pulse peak power equalization of SOA-amplified intensity-modulated optical pulses. The deterministic timing jitter model relies on the pulse mean arrival time estimation and its analytic formula reveals an approximate linear relationship between the deterministic timing jitter and the logarithmic values of intensity modulation when the SOA gain recovery time is faster than the pulse period. The theoretical analysis also arrives at an analytic expression for the intensity modulation reduction (IMR), which clearly elucidates the pulse peak power equalization mechanism of SOA. The IMR analysis shows that the output intensity modulation depth is linearly related to the respective input modulation depth of the optical pulses when the gain recovery time is faster than the pulse period. This novel theoretical platform provides a qualitative and quantitative insight into the SOA performance in case of intensity-modulated optical pulses

Marker assisted selection for resistance against viral nervous necrosis in European seabass (Dicentrarchus labrax)

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