New Couplings of Six-Dimensional Supergravity

We describe the couplings of six-dimensional supergravity, which contain a self-dual tensor multiplet, to $n_T$ anti-self-dual tensor matter multiplets, $n_V$ vector multiplets and $n_H$ hypermultiplets. The scalar fields of the tensor multiplets form a coset $SO(n_T,1)/SO(n_T)$, while the scalars in the hypermultiplets form quaternionic K\"ahler symmetric spaces, the generic example being $Sp(n_H,1)/Sp(n_H)\otimes Sp(1)$. The gauging of the compact subgroup $Sp(n_H) \times Sp(1)$ is also described. These results generalize previous ones in the literature on matter couplings of $N=1$ supergravity in six dimensions.Comment: 24 pages, latex, no figure

The fast-running flies (Diptera, Hybotidae, Tachydromiinae) of Singapore and adjacent regions

This is the first comprehensive introduction to the flies of the subfamily Tachydromiinae (Hybotidae) of Singapore. The monograph summarizes all publications on the Tachydromiinae of Singapore and includes new data resulting from mass-trapping surveys made in Singapore during the last six years. A few samples from Malaysia (Johor province, Pulau Tioman and Langkawi) have been also included in this study. In Singapore the Tachydromiinae are the most diverse group of Empidoidea (except Dolichopodidae) and currently comprise 85 species belonging to the following nine genera: Platypalpus (1), Tachydromia (1), Chersodromia (6), Pontodromia (1), Drapetis (5), Elaphropeza (60), Crossopalpus (1), Nanodromia (3) and Stilpon (7). All species are diagnosed and illustrated. The following 28 species are described as new for science: Chersodromia bulohensis sp. nov. (Singapore), C. glandula sp. nov. (Singapore, Malaysia), C. malaysiana sp. nov. (Singapore, Malaysia), C. pasir sp. nov. (Malaysia), C. sylvicola sp. nov. (Singapore), C. tiomanensis sp. nov. (Malaysia), Crossopalpus temasek sp. nov. (Singapore), Drapetis bakau sp. nov. (Singapore, Malaysia), D. hutan sp. nov. (Singapore), D. laut sp. nov. (Singapore, Malaysia), D. mandai sp. nov. (Singapore), D. pantai sp. nov. (Singapore, Malaysia), Elaphropeza chanae sp. nov. (Singapore), E. collini sp. nov. (Singapore), E. gohae sp. nov. (Singapore), E. kranjiensis sp. nov. (Singapore), E. lowi sp. nov. (Singapore), E. semakau sp. nov. (Singapore), E. shufenae sp. nov. (Singapore), Nanodromia hutan sp. nov. (Singapore), N. spinulosa sp. nov. (Singapore), Platypalpus singaporensis sp. nov. (Singapore), Pontodromia pantai sp. nov. (Singapore), Stilpon arcuatum sp. nov. (Singapore), S. neesoonensis sp. nov. (Singapore), S. nigripennis sp. nov. (Singapore), S. singaporensis sp. nov. (Singapore), S. weilingae sp. nov. (Singapore). A redescription is given for Crossopalpus exul (Osten-Sacken, 1882) (Taiwan). Males of Elaphropeza feminata Shamshev & Grootaert, 2007 and E. modesta Shamshev & Grootaert, 2007 as well as females of Elaphropeza ubinensis Shamshev & Grootaert, 2007 and Nanodromia narmkroi Grootaert & Shamshev, 2003 are described for the first time. Keys to genera and species, which are generally applicable to the whole of Southeast Asia, are compiled. An analysis of the species ecological preferenda is presented

Apoptotic and chemotherapeutic properties of iron(III)-salophene in an ovarian cancer animal model

The cytotoxicity of organometallic compounds iron(III)-, cobalt(III)-, manganese(II)-, and copper(II)-salophene (-SP) on platinum-resistant ovarian cancer cell lines was compared. Fe-SP displayed selective cytotoxicity (IC 50 at ∼1 μM) against SKOV-3 and OVCAR-3 cell lines while Co-SP caused cytotoxic effects only at higher concentrations (IC50 at 60 ?M) and Cu-SP effects were negligible. High cytotoxicity of Mn-SP (30-60 μM) appeared to be nonspecific because the Mn-chloride salt reduced cell viability similarly. The effect of Fe-SP at 1 μM proved to be ovarian cancer cell selective when compared to a panel of cell lines derived from different tumors. The first irreversible step in the induction of cell death by Fe-SP occurred after 3 hrs as indicated by the mitochondrial transmembrane potential (ΔΨm) and was mainly linked to apoptotic, not necrotic events. To evaluate the toxicity of Fe-SP in vivo we conducted an acute toxicity study in rats. The LD 50 of Fe-SP is >2000 mg/kg orally and >5.5 mg/kg body weight by intraperitoneal injection. An ovarian cancer animal model showed that the chemotherapeutic relevant dose of Fe-SP in rats is 0.5-1 mg/kg body weight. The present report suggests that Fe-SP is a potential therapeutic drug to treat ovarian cancer. © 2009 Lange et al, publisher and licensee Dove Medical Press Ltd

Cohomology of symplectic groups and Meyer's signature theorem

Meyer showed that the signature of a closed oriented surface bundle over a surface is a multiple of $4$, and can be computed using an element of $H^2(\mathsf{Sp}(2g, \mathbb{Z}),\mathbb{Z})$. Denoting by $1 \to \mathbb{Z} \to \widetilde{\mathsf{Sp}(2g,\mathbb{Z})} \to \mathsf{Sp}(2g,\mathbb{Z}) \to 1$ the pullback of the universal cover of $\mathsf{ Sp}(2g,\mathbb{R})$, Deligne proved that every finite index subgroup of $\widetilde{\mathsf {Sp}(2g, \mathbb{Z})}$ contains $2\mathbb{Z}$. As a consequence, a class in the second cohomology of any finite quotient of $\mathsf{Sp}(2g, \mathbb{Z})$ can at most enable us to compute the signature of a surface bundle modulo $8$. We show that this is in fact possible and investigate the smallest quotient of $\mathsf{Sp}(2g, \mathbb{Z})$ that contains this information. This quotient $\mathfrak{H}$ is a non-split extension of $\mathsf {Sp}(2g,2)$ by an elementary abelian group of order $2^{2g+1}$. There is a central extension $1\to \mathbb{Z}/2\to\tilde{{\mathfrak{H}}}\to\mathfrak{H}\to 1$, and $\tilde{\mathfrak{H}}$ appears as a quotient of the metaplectic double cover $\mathsf{Mp}(2g,\mathbb{Z})=\widetilde{\mathsf{Sp}(2g,\mathbb{Z})}/2\mathbb{Z}$. It is an extension of $\mathsf{Sp}(2g,2)$ by an almost extraspecial group of order $2^{2g+2}$, and has a faithful irreducible complex representation of dimension $2^g$. Provided $g\ge 4$, $\widetilde{\mathfrak{H}}$ is the universal central extension of $\mathfrak{H}$. Putting all this together, we provide a recipe for computing the signature modulo $8$, and indicate some consequences.Comment: 18 pages. Minor corrections. The most important one is in the table for $g=1$ on page 16: two columns had been swapped in the previous version. This is the version accepted for publication in Algebraic and Geometric Topolog