Infection and coinfection by human papillomavirus, Epstein–Barr virus and Merkel cell polyomavirus in patients with squamous cell carcinoma of the larynx: a retrospective study

Background Human papillomavirus (HPV) is recognized as an important risk factor for laryngeal carcinogenesis. Although HPV-16 and 18 have been strongly implicated, the presence of other high-risk HPV (HR-HPV) genotypes or the coinfection with Epstein-Barr virus (EBV) or Merkel cell polyomavirus (MCPV) may increase the risk, but their etiological association has not been definitively established. Methods We characterized the genotype-specific HPV and the frequency of EBV and MCPV infections through the detection of their DNA in 195 laryngeal specimens of squamous cell carcinoma (SCC) histologically confirmed. Results HPV DNA was detected in 93 (47.7%) specimens. HPV-11 was the most frequent with 68 cases (73.1%), and HPV-52 was the most frequently HR-HPV found with 51 cases, which corresponds to 54.8% of all HPV-positive specimens. EBV DNA was detected in 54 (27.7%) tumor tissue specimens of which 25 (46.3%) were in coinfection with HPV. MCPV DNA was detected only in 11 (5.6%) cases of which 5 (45.4%) were in coinfection with an HR-HPV. No association between the presence of DNA of the three examined viruses and the patient smoking habits, alcohol consumption, age, the keratinization status, differentiation grade, or localization of the tumor in the larynx were found. Discussion HPV-52 was the most prevalent HR-HPV, which may suggest that this and other genotypes in addition to HPV-16 and 18 could be considered for prophylaxis. However, further studies including non-cancer larynx cases and the evaluation of other molecular markers and viral co-infection mechanisms are needed to determine the role of the different HR-HPV genotypes, EBV, and MCPV in the etiology of SCC of the larynx

The morphology, environment and interstellar medium of early-type galaxies as a means for studying the evolution of galaxies outside of clusters

The main goal of this thesis is to study the properties of isolated early-type galaxies with the hope of learning about their formation and evolution. With this goal in mind, B and I optical, and Ks near infrared images of 4 different samples of early-type galaxies in contrasting galactic density environments have been secured with the Steward Observatory 90 inch and 61 inch telescopes. The 4 early-type galaxy samples consist of: a sample extracted from the Catalog of Isolated Galaxies of Karachentseva, a sample of isolated galaxies previously studied by Fasano and Bonoli, a sample of galaxies from the Hickson Compact Groups Catalog, and a sample of galaxies with detected ISM's. This data set is used to examine whether differences in the galactic environment are related to differences in key properties of early-type galaxies. Multi-color surface photometry analysis is performed on the 4 samples, and the results are used in several contexts. For most of the galaxies in the Karachentseva sample surface photometry is reported for the first time. Likewise, Ks data for most of the objects in this thesis have never been reported. The light profile of the galaxies are fitted with Sersic profile functions. In agreement with other investigations, it is found that the Sersic parameter, n is primarily dependent on the galaxy size, and does not seem to be strongly dependent on properties such as environment or ISM content. The (B - I) color index, ellipticity, position angle, and third and fourth-order Fourier coefficients are derived from the surface photometry. It is confirmed that the third-order coefficients signal the presence of dust, and that the coefficient of the cos(4θ) gives structural information of the galaxies. Furthermore, the subtraction of model ellipticals has revealed peculiarities in the morphology, such as disks, spiral arms, dust lanes, multiple nuclei, etc. The largest and most relevant sample in this investigation consists of 39 galaxies, and it contains ∼25% of the galaxies classified as ellipticals in the Karachentseva catalog. Only approximately one half of the galaxies classified as ellipticals in that catalog appear to be correctly classified, a result which may imply a reduction of the percentage of ellipticals in the Karachentseva catalog to ∼6% of the total population of Isolated Galaxies. A significant number of merger candidates has also been found among the isolated galaxies. It is argued that the fraction of merger candidates to isolated ellipticals can be used to constrain models for the evolution of compact groups into isolated galaxies. The results of CO(1-0) millimetric wavelength observations taken at the NRAO 12 M telescope, as well as submillimeter continuum emission from dust at the SMT are also presented

Hydrodynamic Modeling of the Interaction of Winds within a Collapsing Turbulent Gas Cloud

By using the particle-based code Gadget2, we follow the evolution of a gas giant molecular cloud, in which a set of gas particles representing the wind are created by a Monte Carlo scheme and suddenly move outwards from the cloud’s center. The particles representing the gas cloud initially have a velocity according to a turbulent spectrum built in a Fourier space of 643 grid elements. The level of turbulence and the temperature of the cloud are both adjusted so that a gravitational collapse of the cloud is initially induced. All the winds are activated in a very early stage of evolution of the cloud. We consider only two kinds of winds, namely, one with spherical symmetry and the second one of a bipolar collimated jet. In order to assess the dynamical change in the cloud due to interactions with the winds, we show isovelocity and isodensity plots for all our simulations. We also report on the accretion centers detected at the last simulation time available for each model

Education and public outreach at the Carl Sagan Solar Observatory of the University of Sonora

We discuss the importance of small solar observatories for EPO (Education and Public Outreach), mentioning why they are relevant and what kind of equipment and software require. We stress the fact that technological advances have made them affordable and that they should be widely available. This work is a result of our experience with one: The Carl Sagan Solar Observatory (CSSO). We briefly describe its status and the solar data obtained daily with students participation. We present examples of the data obtained in the visible, Ca II and two in Hα. Data which is widely used for education. Finally we talk about the capability for remote operation as an open invitation for collaboration in educational and scientific projects

The Carl Sagan Observatory: A Telescope for Everyone

The Carl Sagan Observatory is a new project for a remote observatory that will be built at the summit of Cerro Azul (a 2480 m mountain located near Magdalena. Sonora, Mexico). It will include one 55 cm and four 14 cm telescopes. The 55 cm telescope will be dedicated to supernovae research. One of the 14 cm Maksutov telescopes will be used as an autoguider for the stellar observations. The other 14 cm telescopes will feature different narrow band filters that will be used for solar research. The observatory will be controlled from the campus of the U niversidad de Sonora in Hermosillo, Sonora, Mexico ( ~ 200 km from the site). A prototype of the observatory building has been built on campus and first light is expected by the end of May of 2001. We expect to have an operating mountain observatory by the end of 2002. Some of the unique technical aspects of this observatory, which we believe can be a model for future small telescope observatories are discussed in this work

Multifrequency Study of the Blazar 3C 454.3

This work is devoted to multi-frequency studying of the blazar 3C 454.3. The study includes spectroscopic and photometric observations in the optical, IR, and gamma-ray bands. We investigate whether a correlation exists in the light curves at different wavelengths. We have carried out observations of the optical spectrum (from 4000 to 7000 Angstroms) between 2007 and 2009, and identified MgII [2800 Angstroms] and FeII emission line features. We have obtained optical magnitudes and color indices of the quasar and performed a correlation between the optical, IR, and gamma-ray light curves. We have found statistically significant correlations between the light curves at different wavelengths

Supernovas, faros en el universo: medición de la distancia a ASASSN-15hx

Difícil pensar en un evento astronómico tan relevante y polifacético como la gigantesca explosión de supernova, que en breves segundos destruye su estrella, creando un gran número de elementos pesados. El inmenso brillo de las supernovas permite observarlas a enormes distancias, para así obtener información cosmológica. En este trabajo abordamos en general el tema de supernovas, enfocándonos luego al estudio de la supernova de tipo Ia ASASSN-15hx. Presentamos las observaciones realizadas en diferentes filtros y mostramos un método basado en el ancho de su curva de luz para estimar su distancia y corrimiento al rojo. Los valores obtenidos coinciden con información encontrada en la literatura y las incertidumbres obtenidas están dentro del rango de las encontradas con otros métodos