Galaxy groups in the 2dF redshift survey: The catalogue

We construct a galaxy groups catalogue from the public 100K data release of the 2dF galaxy redshift survey. The group identification is carried out using a slightly modified version of the group finding algorithm developed by Huchra & Geller. Several tests using mock catalogues allow us to find the optimal conditions to increase the reliability of the final group sample. A minimum number of 4 members, an outer number density enhancement of 80 and a linking radial cutoff of $200 km sec^{-1}$, are the best obtained values from the analysis. Using these parameters, approximately 90% of groups identified in real space have a redshift space counterpart. On the other hand the level of contamination in redshift space reaches to 30 % including a $\sim 6$ of artificial groups and $\sim 24$ of groups associated with binaries or triplets in real space. The final sample comprise 2209 galaxy groups covering the sky region described by Colless et al. spanning over the redshift range of $0.003 \leq z \leq 0.25$ with a mean redshift of 0.1.Comment: Accepted for publication in the MNRAS. 8 figures 8 page

Photo-damage, photo-protection and age-related macular degeneration

Age-related macular degeneration (AMD) is a degenerative retinal disease that causes blindness in people 60-65 years and older, with the highest prevalence appearing in people 90 years-old or more. Epidemiological estimates indicate that the number of cases is increasing, and will almost double in the next 20 years. Preventive measures require precise etiological knowledge. This is quite difficult, since AMD is a multifactorial condition with intricate relationships between causes and risk factors. In this review, we describe the impact of light on the structure and physiology of the retina and the pigment epithelium, taking into account the continuous exposure to natural and artificial light sources along the life of an individual. A large body of experimental evidence demonstrates the toxic effects of some lighting conditions on the retina and the pigment epithelium, and consensus exists about the importance of photo-oxidation phenomena in the causality chain between light and retinal damage. Here, we analyzed the transmission of light to the retina, and compared the aging human macula in healthy and diseased retinas, as shown by histology and non-invasive imaging systems. Finally, we have compared the putative retinal photo-sensitive molecular structures that might be involved in the genesis of AMD. The relationship between these compounds and retinal damage supports the hypothesis of light as an important initiating cause of AMD.Fil: Marquioni Ramella, Melisa Daniela. Universidad Austral. Facultad de Ciencias Biomédicas. Laboratorio de Investigaciones Biomédicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Suburo, Angela Maria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Austral. Facultad de Ciencias Biomédicas. Laboratorio de Investigaciones Biomédicas; Argentin

"Imeneo sotto il platano": un motivo bucolico in Claudiano (carm. min. 25)

Nelle scene del sonno di Venere e del dialogo tra Venere e Imeneo, l’Epitalamio per Palladio e Celerina di Claudiano (carm. min. 25) si distingue dalla tradizione epitalamica per l'atmosfera bucolica, evocata da una serie di riferimenti tematici e formali al genere letterario. Le parole di Venere e Imeneo sembrano comunicare un articolata riflessione dell'autore sulla poetica espressa nell'epitalamio: Imeneo fungerebbe da portavoce di Claudiano, rivendicando la possibilità per il poeta di adattare i toni bucolici alle esigenze encomiastiche del carme d occasione. È possibile che lo sviluppo narrativo dell'episodio di Imeneo sia stato suggerito a Claudiano dall'inno cletico del carme 61 di Catullo. Claudiano potrebbe aver sfruttato le possibilità offerte dalla forma dell'epitalamio epico per fare dell'invocazione a Imeneo un episodio organico al racconto.In the scenes of Venus’ sleep and of the dialogue between Venus and Hymenaeus, Claudian's Epithalamium for Palladius and Celerina (carm. min. 25) stands out from the epithalamic tradition for its bucolic atmosphere, which is summoned by several thematic and stylistic references to the literary genre. The words of Venus and Hymenaeus seem to communicate an articulate reflection of the author on the poetics of the epithalamium: Hymenaeus may be acting as spokesman for Claudian, claiming the possibility for the poet to adapt the bucolic modes to the encomiastic needs of the occasional poem. The narrative development of Hymenaeus’ episode might have been suggested to Claudian by the cletic hymn of Catullus 61. Claudian seems to have taken advantage of the possibilities offered by the form of the epic epithalamium in order to make the invocation to Hymenaeus an episode incorporated in the narrative

Untied to economic fluctuations, insurers are less likely to generate systemic risks

But it's important not to overlook nuances in their macroprudential regulation, writes Marcelo Ramell

Endothelial MMP-9 Drives the Inflammatory Response in Abdominal Aortic Aneurysm (AAA)

Abdominal aortic aneurysm (AAA) is a complex multi-factorial disease leading to life-threatening complications. Chronic inflammation and extracellular matrix degradation are the major pathological features of AAA. Vascular inflammation involves complex interaction among inflammatory cells (i.e. neutrophils, lymphocytes, monocytes, macrophages), endothelial cells (ECs), vascular smooth muscle cells (VSMCs), and extracellular matrix (ECM). Although vascular endothelium plays a key role in aneurysm disease, the molecular mechanisms underlying its involvement is only partially understood. In this study, we have characterized the role of matrix matrix metalloproteinase-9 (MMP-9) as potential trigger of the inflammatory response during the reciprocal interaction between ECs and VSMCs. Briefly, in biopsies of human AAA we found increased level of MMP-9, IL-6 and monocyte chemoattractant protein-1 (MCP-1), which correlated with a massive medial neo-angiogenesis. In particular, in vitro silencing of MMP-9 in ECs, using specific shRNA delivered by lentiviral vectors, inhibited TNF-alpha mediated activation of NF-kB. In addition, ECS void of MMP-9 failed to migrate in 3D matrix and affected VSMC behavior in terms of matrix remodeling. Overall our findings indicate that silencing of MMP-9 may represent a therapeutic target to restore vascular extracellular matrix remodeling