The Spectrum of Static Subtracted Geometries

Subtracted geometries are black hole solutions of the four dimensional STU model with rather interesting ties to asymptotically flat black holes. A peculiar feature is that the solutions to the Klein-Gordon equation on this subtracted background can be organized according to representations of the conformal group $SO(2,2)$. We test if this behavior persists for the linearized fluctuations of gravitational and matter fields on static, electrically charged backgrounds of this kind. We find that there is a subsector of the modes that do display conformal symmetry, while some modes do not. We also discuss two different effective actions that describe these subtracted geometries and how the spectrum of quasinormal modes is dramatically different depending upon the action used.Comment: 30 pages, 2 figures. v2: references added. v3: minor corrections to match with published versio

An Investigation into the Physiological Role of Annexin A11

Annexin A11 is a ubiquitously expressed member of the annexin family of Ca2+-dependent phospholipid binding proteins, which lies at the root of the vertebrate annexin evolutionary tree. Annexin A11 is known to be localised to the nuclei of cells in culture, and to interact Ca2+-dependently in vitro with the S100 protein S100A6 and the penta EF-hand protein ALG-2 through its long glycine, proline and tyrosine-rich N-terminal domain, but very little is known about the physiological functions performed by this annexin in vivo. An investigation into the cellular roles of annexin A11 both in interphase and during cell division is presented in this thesis. Using various molecular and cell biology approaches, annexin A11 was identified in the nucleus and in cytoplasmic vesicles that appear to be transported along the microtubular network, linking annexin A11 function with intracellular membrane trafficking processes. Annexin A11 has also been identified in membrane domains involved in signal transduction at the basolateral membrane of A431 cells. A role for this annexin in membrane remodelling steps during cell growth is proposed in view of the accumulation of annexin A11-containing vesicles in the cytoplasm of non-contact inhibited cells and at the leading edge of monolayer outgrowths, together with the concentration of annexin A11 at the cell-cell contact sites in the plasma membrane of confluent monolayers. Annexin A11 relocates to the nuclear envelope and is tyrosine-phosphorylated in the presence of calcium in interphase cells, and invades the nuclear envelope at the invaginations created during nuclear envelope breakdown at the onset of mitosis, and is also detected at the nuclear envelope during nuclear envelope reassembly after cell division, making the nuclear envelope a specific target for annexin A11. The study of the function of annexin A11 during cell division led to the identification of an essential role for annexin A11 in the terminal phase of cytokinesis. Annexin 11 was observed to translocate from the nucleus to the spindle poles in metaphase, and then to the spindle midzone in anaphase, and to be recruited to the midbody in late telophase where it co-localises and associates with the mitotic kinesin- like protein CHO1. Depletion of annexin A11 by RNA interference has shown that the absence of this annexin leads to failure to establish a functional midbody, incomplete daughter cell separation, and ultimately cell death by apoptosis

A new species of Paracapillaroides (Nematoda: Capillariidae) parasitizing Nemadactylus bergi (Perciformes: Latridae) from the Argentine Sea

A new nematode species, Paracapillaroides acanthocotylus sp. n., is described from the marine fish Nemadactylus bergi (Norman) (Latridae, Perciformes) from waters off Mar del Plata, Argentina (38°08'S, 57°32'W) (prevalence 81.8%, mean intensity 12.4 ± 10.3). The new species is readily distinguished from P. agonostomi Moravec, Salgado-Maldonado et Caspeta-Mandujano, 1999, the only known species of the genus, by having in both sexes a longer oesophagus in relation to total body length. Males of the new species have a shorter and more complex spicule and a markedly different morphology of the spicular sheath; the rays supporting the caudal bursa are also shorter and rounded, instead of digitiform. Furthermore, females of the new species have elevated vulval lips and longer eggs. The complex structure of both the spicule and spicular sheath is unique among all capillariids parasitizing cold-blooded vertebrates. This is the first record of a species of Paracapillaroides in the southwestern Atlantic Ocean.Fil: Rossin, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Timi, Juan Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

An investigation into the physiological role of annexin A11

The calcium-dependent phospholipid-binding protein annexin A11 was discovered over 25 years ago, however little is known about its function. This thesis supports a role for annexin A11 in the cell cycle and suggests an association with the microtubule network. Recent studies have implicated annexin A11 in the autoimmune disease sarcoidosis, which is further investigated in this study. A single nucleotide polymorphism within annexin A11 (R230C) was identified as a highly associated susceptibility locus for sarcoidosis. Over-expression of annexin A11WT and annexin A11R230C showed no difference in their distribution. Stimulation with ionomycin, which induces a rise in intracellular calcium, resulted in the translocation of both variants to the plasma membrane and nuclear envelope with approximately the same time course. The calcium-dependent translocation of annexin A11 is therefore unaffected by the R230C mutation. In this one aspect there appears to be no difference between the two variants, however much still remains to be investigated such as the potential extracellular roles of these variants and their function in immune cells. Much of the work in this thesis has focused on elucidating the function of wild type annexin A11, particularly during the cell cycle. During mitosis the distribution of annexin A11 is highly dynamic and localises to the mitotic spindle at metaphase and anaphase, as well as the midbody at cytokinesis. The use of methanol fixation highlighted the co-localisation of annexin A11 with the microtubule network throughout mitosis, as well as at interphase. Furthermore annexin A11 was shown to concentrate at the centrosome, again during both mitosis and interphase. Several centrosomal proteins also localise to the midbody and are key regulators of mitotic progression, supporting a similar role for annexin A11. Furthermore the centrosomal localisation of annexin A11 may serve as an ideal docking site from which it can be easily targeted throughout the cell. This study highlights the novel localisation of annexin A11 to the centrosome and the microtubule network. Furthermore these findings contribute to a growing picture for the role of annexin A11 in the cell cycle, particularly with regards to its use of the microtubule network – a feature which may also have a role in interphase cells.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Annexin 11 is required for midbody formation and completion of the terminal phase of cytokinesis

Annexins are Ca2+-binding, membrane-fusogenic proteins with diverse but poorly understood functions. Here, we show that during cell cycle progression annexin 11 translocates from the nucleus to the spindle poles in metaphase and to the spindle midzone in anaphase. Annexin 11 is recruited to the midbody in late telophase, where it forms part of the detergent-resistant matrix that also contains CHO1. To investigate the significance of these observations, we used RNA interference to deplete cells of annexin 11. A combination of confocal and video time-lapse microscopy revealed that cells lacking annexin 11 fail to establish a functional midbody. Instead, daughter cells remain connected by intercellular bridges that contain bundled microtubules and cytoplasmic organelles but exclude normal midbody components such as MKLP1 and Aurora B. Annexin 11–depleted cells failed to complete cytokinesis and died by apoptosis. These findings demonstrate an essential role for annexin 11 in the terminal phase of cytokinesis

EGF receptor trafficking: consequences for signaling and cancer

The ligand-stimulated epidermal growth factor receptor (EGFR) has been extensively studied in the analysis of molecular mechanisms regulating endocytic traffic and the role of that traffic in signal transduction. Although such studies have largely focused on mitogenic signaling and dysregulated traffic in tumorigenesis, there is growing interest in the potential role of EGFR traffic in cell survival and the consequent response to cancer therapy. Here we review recent advances in our understanding of molecular mechanisms regulating ligand-stimulated EGFR activation, internalization, and post-endocytic sorting. The role of EGFR overexpression/mutation and new modulators of EGFR traffic in cancer and the response to cancer therapeutics are also discussed. Finally, we speculate on the relationship between EGFR traffic and cell survival

An endemic Taenia from South America: validation of T. talicei Dollfus, 1960 (Cestoda: Taeniidae) with characterization of metacestodes and adults

Taenia talicei is redescribed based on new data from polycephalic, fimbriocercus and cysticercus metacestodes found in Ctenomys spp. (Rodentia: Ctenomyidae) from Argentina. Strobilate adult specimens, derived from experimental infections in domestic dogs, are described for the first time. Identity of the adult and metacestodes stages is based on the number of rostellar hooks (44–50 hooks in 2 rows), their dimensions (large hooks= 232–242; small= 150–187) and shape. Taenia talicei is distinguished from those species that occur naturally in Neotropical Felidae and from those cosmopolitan species that circulate in synanthropic cycles with rodents (or lagomorphs) and domestic hosts such as cats and dogs in South America based on the structure of the metacestode, dimensions and numbers of rostellar hooks and a suite of specific characters of the genital system in strobilate adults. This species is the first that can be considered endemic to South America. Origins of an endemic Taenia species or taeniid assemblages in South America would have relationships to either North American or Eurasian placental carnivores. In these instances, the expansion of Taenia may have resulted from geographic colonization of South America, radiation in both felids (and canids), and host switching by tapeworms to caviomorphs, prior to the emergence of the Panamanian Isthmus. Taenia talicei is capable of development in domestic dogs, and metacestodes in species of Ctenomys were found in urban or semi-urban environments. These factors may establish a role for synanthropic cycles linked to definitive hosts including dogs and cats as a route for exposure of humans to infection by this taeniid.Fil: Rossin, Maria Alejandra. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología. Laboratorio de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Timi, Juan Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología. Laboratorio de Parasitología; ArgentinaFil: Hoberg, Eric P.. United States Department of Agriculture. Agricultural Research Service; Argentin

The nebular emission of star-forming galaxies in a hierarchical universe

Galaxy surveys targeting emission lines are characterizing the evolution of star-forming galaxies, but there is still little theoretical progress in modelling their physical properties. We predict nebular emission from star-forming galaxies within a cosmological galaxy formation model. Emission lines are computed by combining the semi-analytical model SAG with the photoionization code MAPPINGS-III. We characterize the interstellar medium of galaxies by relating the ionization parameter of gas in galaxies to their cold gas metallicity, obtaining a reasonable agreement with the observed Hα, [O II] λ 3727, [O III] λ 5007 luminosity functions, and the BPT diagram for local star-forming galaxies. The average ionization parameter is found to increase towards low star formation rates and high redshifts, consistent with recent observational results. The predicted link between different emission lines and their associated star formation rates is studied by presenting scaling relations to relate them. Our model predicts that emission-line galaxies have modest clustering bias, and thus reside in dark matter haloes of masses below Mhalo ≲ 1012 [h−1 M⊙]. Finally, we exploit our modelling technique to predict galaxy number counts up to z ∼ 10 by targeting far-infrared emission lines detectable with submillimetre facilities.Fil: Orsi, Alvaro. Pontificia Universidad Católica de Chile; ChileFil: Padilla, Nelson David. Pontificia Universidad Católica de Chile; ChileFil: Groves, Brent. Max Planck Institute For Astronomy;Fil: Cora, Sofia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica la Plata; ArgentinaFil: Tecce, Tomas Enrique. Pontificia Universidad Católica de Chile; ChileFil: Gargiulo, Ignacio Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica la Plata; ArgentinaFil: Ruiz, Andrés Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomia Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomia Teórica y Experimental; Argentin

El Empleo y su promoción en Argentina y Bolivia : el rol de las ONG’s

Teniendo en cuenta la importancia social que reviste el empleo en un país, no sólo como fuente de ingresos sino además como generador de dignidad y desarrollo personal de sus habitantes, creemos que esta variable debe estar comprendida en el centro de las discusiones y estudios sobre la región. Por este motivo, consideramos preciso examinar la evolución de indicadores y analizar distintas experiencias de fomento del empleo a través de las ONG’s, para así intentar comprender mejor la realidad de nuestros países en esta materia y difundir los esfuerzos realizados en su promoción. En el siguiente trabajo nos proponemos analizar las características y las acciones de fomento del empleo en Argentina y Bolivia a través del análisis de evolución de distintos indicadores y casos de la realidad. Para ello pretendemos determinar las características propias y comunes del empleo y su evolución en las últimas décadas en cada uno de estos países. Además, intentaremos examinar las propuestas y los resultados de casos específicos de fomento del empleo llevados a cabo por ONG´s de ambos países