Semi-Analytic Techniques for Solving Quasi-Normal Modes

In this chapter, we discuss an approach to obtaining black hole quasi-normal modes known as the asymptotic iteration method, which was initially developed in mathematics as a new way to solve for eigenvalues in differential equations. Furthermore, we demonstrate that the asymptotic iteration method allows one to also solve for the radial quasi-normal modes on a variety of black hole spacetimes for a variety of perturbing fields. A specific example for Dirac fields in a general dimensional Schwarzschild black hole spacetime is given, as well as for spin-3/2 field quasi-normal modes

(Dithio­benzoato-κ2 S,S′)[hydridotris(pyrazol-1-yl-κN 2)borato](triphenyl­phosphine-κP)ruthenium(II)

Reaction of [Ru(Tp)Cl(PPh3)2] (Tp = hydridotrispyrazolyl­borate) with ammonium dithio­benzoate in methanol leads to the formation of the title compound, [Ru(C9H10BN6)(C7H5S2)(C18H15P)]. In the crystal structure, the Ru atom is coordinated by three N atoms of the Tp ligand, one P atom of the triphenyl­phosphine ligand and the two S atoms of the dithio­benzoate ligand within a slightly distorted octa­hedron. The Ru—S bonds are slightly different [2.321 (1) and 2.396 (1) Å] and the average N—Ru—N angle is 86.31°

(Benzonitrile-κN)chlorido[hydrido­tris(pyrazol-1-yl-κN 2)borato](triphenyl­phosphine-κP)ruthenium(II) ethanol solvate. Corrigendum

Corrigendum to Acta Cryst. (2009), E65, m438

Brief report: A pilot study of the use of a virtual reality headset in autism populations

The application of virtual reality technologies (VRTs) for users with autism spectrum disorder (ASD) has been studied for decades. However, a gap remains in our understanding surrounding VRT head-mounted displays (HMDs). As newly designed HMDs have become commercially available (in this study the Oculus Rift™) the need to investigate newer devices is immediate. This study explored willingness, acceptance, sense of presence and immersion of ASD participants. Results revealed that all 29 participants (mean age=32; 33% with IQ< 70) were willing to wear the HMD. The majority of the participants reported an enjoyable experience, high levels of ‘presence’, and were likely to use HMDs again. IQ was found to be independent of the willingness to use HMDs and related VRT immersion experience

(Benzonitrile-κN)chlorido[hydrido­tris(pyrazol-1-yl-κN 2)borato](triphenyl­phosphine-κP)ruthenium(II) ethanol solvate

The reaction of [Ru(C9H10BN6)Cl(C18H15P)2] with benzo­nitrile leads to crystals of the title compound, [Ru(C9H10BN6)Cl(C18H15P)(C7H5N)]·C2H5OH. In the crystal structure, the environment about the ruthenium metal center corresponds to a slightly distorted octa­hedron with an average N—Ru—N bite angle of the Tp ligand of 86.6 (2)°

Methyl­ene bis­(dithio­benzoate)

In the title compound, C15H12S4, two phenyl­dithio­carboxyl­ate units are linked through a methyl­ene C atom on a twofold rotation axis. The central S—CH2—S angle of 116.9 (5)° is significantly larger than the ideal tetra­hedral value. The dihedral angle formed by the two phenyl rings is 68.2 (1)°. The refined Flack parameter of 0.2 (3) does not permit unambiguous determination of the absolute structure

(Benzophenone imine-κN)­chlorido(hydrido­tripyrazolyl­borato)­(triphenyl­phosphine)ruthenium(II) diethyl ether solvate

The reaction of RuCl(Tp)(Ph3P)2, where Tp is [(CH)3N2]3BH, with benzophenone imine leads to the formation of the title compound, [Ru(C9H10BN6)Cl(C13H11N)(C18H15P)]·C4H10O. The environment about the Ru atom corresponds to a slightly distorted octa­hedron and the bite angle of the Tp ligand produces an average N—Ru—N angle of 86.3 (9)°. The three Ru—N(Tp) bond lengths [2.117 (2), 2.079 (2) and 2.084 (2) Å] are slightly longer than the average distance (2.038 Å) in other ruthenium–Tp complexes

Definitive radiotherapy for early stage glottic cancer by 6 MV photons

Purpose: To evaluate the clinical outcome of early glottic cancer (GC) treated by primary radiotherapy (RT) with 6 MV photons. Methods and materials: We retrospectively reviewed the medical records of 695 consecutive patients with T1N0 and T2N0 GC treated between 1983 and 2005 by RT in our institution. Clinical outcome in terms of local control (LC), overall survival (OS) and cause- specific survival (CSS) rate were evaluated. Results: The median follow-up time was 10.5 years.The 10-year actuarial LC rates were as follows: T1A, 91%; T1B, 87%; T2, 77%. The 10-year OS were as follows: T1, 74.2%; T2, 70.7%. The 10-year CSS were as follows: T1, 97.7%; T2, 97.1%. Poorly differentiated histology and tumor biologically effective dose < 65 Gy.© 2012 Tong et al.; licensee BioMed Central Ltd.Link_to_subscribed_fulltex

(O,O′-Diethyl dithio­phosphato-κ2 S,S′)(hydridotripyrazol-1-ylborato-κ3 N 2,N 2′,N 2′′)(triphenyl­phosphine-κP)ruthenium(II)

Reaction of [Ru(Tp)Cl(PPh3)2] {where Tp is hydridotri­pyrazol­yl­borate, BH[C3H3N2)3)]} with NH4[S2P(OEt)2] in methanol afforded the title compound, [Ru(C9H10BN6)(C4H10O2PS2)(C18H15P)], in which the RuII ion is in a slightly disorted octa­hedral coordination environment. The [S2P(OEt)2]− ligand coordinates in a chelating mode with two similar Ru—S bond lengths and a slightly acute S—Ru—S angle. The atoms of both –OCH2CH3 groups of the diethyl dithio­phosphate ligand are disordered over two sites with approximate occupancies of 0.76 and 0.24

Azido­(1,1-diphenyl­methanimine-κN)[hydridotris(pyrazolyl-κN 2)borato](triphenyl­phosphine-κP)ruthenium(II) diethyl ether solvate

The reaction of [RuCl(C9H10BN6)(C18H15P)2] with benzo­phenone imine in methanol, in the presence of sodium azide, leads to the formation of the title compound, [Ru(C9H10BN6)(N3)(HN=CPh2)(C18H15P)]·C4H10O, which crystallizes as the diethyl ether solvate. In the crystal structure, the Ru atom is coordinated by three N atoms of one hydridotris(pyrazoly)borate anion, one P atom of one triphenyl­phosphine ligand, one N atom of the azide anion and one N atom of the benzophenone­imine ligand in a slightly distorted octa­hedral geometry. The azide anion is almost linear [177.0 (5)°], with an Ru—N—N angle of 125.9 (3)°. There is a small difference between the N—N distances [1.200 (5) and 1.164 (5) Å], the longer bond being adjacent to the Ru atom