Identification of 5,6-trans-epoxyeicosatrienoic acid in the phospholipids of red blood cells.

A novel eicosanoid, 5,6-trans-epoxy-8Z,11Z,14Z-eicosatrienoic acid (5,6-trans-EET), was identified in rat red blood cells. Characterization of 5,6-trans-EET in the sn-2 position of the phospholipids was accomplished by hydrolysis with phospholipase A(2) followed by gas chromatography/mass spectrometry as well as electrospray ionization-tandem mass spectrometry analyses. The electron ionization spectrum of 5,6-erythro-dihydroxyeicosatrienoic acid (5,6-erythro-DHET), converted from 5,6-trans-EET in the samples, matches that of the authentic standard. Hydrogenation of the extracted 5,6-erythro-DHET with platinum(IV) oxide/hydrogen resulted in an increase of the molecular mass by 6 daltons and the same retention time shift as an authentic standard in gas chromatography, suggesting the existence of three olefins as well as the 5,6-erythro-dihydroxyl structure in the metabolite. Match of retention times by chromatography indicated identity of the stereochemistry of the red blood cell 5,6-erythro-DHET vis à vis the synthetic standard. High pressure liquid chromatography-electrospray ionization-tandem mass spectrometry analysis of the phospholipase A(2)-hydrolyzed lipid extracts from red blood cells revealed match of the mass spectrum and retention time of the compound with the authentic 5,6-trans-EET standard, providing direct evidence of the existence of 5,6-trans-EET in red blood cells. The presence of other trans-EETs was also demonstrated. The ability of both 5,6-trans-EET and its product 5,6-erythro-DHET to relax preconstricted renal interlobar arteries was significantly greater than that of 5,6-cis-EET. In contrast, 5,6-cis-EET and 5,6-trans-EET were equipotent in their capacity to inhibit collagen-induced rat platelet aggregation, whereas 5,6-erythro-DHET was without effect. We propose that the red blood cells serve as a reservoir for epoxides which on release may act in a vasoregulatory capacity

Tailoring galaxies: Size–luminosity–surface brightness relations of bulges and disks along the morphological sequence

International audienceAims. We revisit the scaling relations between size, luminosity, and surface brightness as a function of morphology, for the bulge and disk components of the 3106 weakly inclined galaxies of the “Extraction de Formes Idéalisées de Galaxies en Imagerie” (EFIGI) sample, in the nearby Universe. Methods. The luminosity profiles from the Sloan Digital Sky Survey (SDSS) gri images were modeled as the sum of a Sérsic (bulge) and an exponential (disk) component for cD, elliptical (E), lenticular, and spiral galaxies, or as a single Sérsic profile for cD, E, dE, and irregular (Im) galaxies, by controlled profile fitting with the SourceXtractor++ software. Results. For the EFIGI sample, we remeasured the Kormendy (1977, ApJ, 218, 333) relation between effective surface brightness ⟨ μ ⟩ e and effective radius R e of elliptical galaxies, and show that it is also valid for the bulges (or Sérsic components) of galaxy types Sb and earlier. In contrast, there is a progressive departure toward fainter and smaller bulges for later Hubble types, as well as with decreasing bulge-to-total ratios ( B / T ) and Sérsic indices. This depicts a continuous transition from pseudo-bulges to classical ones, which we suggest to occur for absolute g magnitudes M g between −17.8 and −19.1. We also obtain partial agreement with the Binggeli et al. (1984, AJ, 89, 64) relations between effective radius and M g (known as “size–luminosity” relations, in log–log scale) for E and dE galaxies. There is a convex size–luminosity relation for the bulges of all EFIGI types. Both ⟨ μ ⟩ e − R e and R e − M g scaling relations are projections of a plane in which bulges are located according to their value of B / T , which partly determines the morphological type. Analogous scaling relations were derived for the disks of lenticular and spiral types, and the irregulars. The curvature of the size–luminosity relation for disks is such that while they grow, they first brighten and then stabilize in surface brightness. Moreover, we obtain the unprecedented result that the effective radii of both the bulges and disks of lenticular and spiral galaxies increase as power laws of B / T , with a steeper increase for the bulges. Both bulges and disks of lenticular galaxies have a similar and largely steeper increase with B / T than those for spirals. These relations propagate into a single scaling relation for the disk-to-bulge ratio of effective radii across ∼2 orders of magnitude in B / T , and for all types. We provide the parameters of all of these relations that can be used to build realistic mock images of nearby galaxies. The new convex size–luminosity relations are more reliable estimates of bulge, disk, and galaxy sizes at all magnitudes in the nearby Universe. Conclusions. This analysis describes the joint size and luminosity variations of bulges and disks along the Hubble sequence. The characteristics of the successive phases of disk and bulge size growth strengthen a picture of morphological evolution in which irregulars and late spirals merge to form earlier spirals, lenticulars, and eventually ellipticals

Queer-friendly neighbourhoods: interrogating social cohesion across sexual difference in two Australia neighbourhoods

This paper examines processes of social cohesion across sexual difference in 'queer-friendly neighbourhoods'-localities that have a heterosexual majority in residential and commercial terms, but where a significant presence of gay and lesbian residents, businesses, and organisations are welcomed. This investigation advances a lineage of work on the development and maintenance of gay and lesbian neighbourhoods, and their role in residents' well-being. The findings also extend understandings of social cohesion, a key theme in neighbourhood and policy research across the West. The context of this study is Australia, where recent projects on social cohesion have focused on public order, economic benefits, and race tensions. However, given that gay men and lesbians are present in Australian social and political debates, sexuality should be integrated into studies about neighbourhood cohesion. To analyse processes of cohesion between heterosexual and same-sex-attracted people, we draw on data from case studies of two queer-friendly neighbourhoods in Australia-the inner-city suburb of Newtown, NSW, and the regional town of Daylesford, Victoria. We discuss the findings in three analytical categories to highlight common processes and characteristics of queer-friendly neighbourhoods: diversity and difference; symbolic landscapes; combating homophobia

Cosmopolitan knowledge and the production and consumption of sexualized space: Manchester's gay village

According to Žižek (1997) the logic of late capitalism offers opportunities for the incorporation of previously marginalised groups, whilst simultaneously dividing them at the same time. These possibilities for incorporation create divisions on the basis of gender, race, sexuality and class. Here, we examine how the capitalist desire for opening new markets for leisure consumption with new forms of branding, alongside the desire for the territorialisation of space by campaigning gay and lesbian groups, has led to the formation of a ‘gay space’ marketed as a cosmopolitan spectacle, in which the central issue becomes a matter of access and knowledge: who can use, consume and be consumed in gay space? We also ask what is the radical political impetus of sexual politics when commodified as cosmopolitan and incorporated spatially? The paper grounds the examination of the politics of cosmopolitanism within a specific locality drawing upon research undertaken on the contested use of space within Manchester's gay village. The paper is organised into four sections. The first examines competing definitions of cosmopolitanism, exploring how sexuality and class are framed as conceptual limits. The second describes how Manchester's gay village is imagined and branded as cosmopolitan. The third considers the navigation and negotiation of difference within this space. The final section evaluates the exclusions from cosmopolitan space and pursues the significance of this for arguments about incorporation in late capitalism