The visible environment of polar ring galaxies

A statistical study of the environment around Polar Ring Galaxies is presented. Two kinds of search are performed: 1) a study of the concentration and diameters of all the objects surrounding the Polar Rings, within a search field 5 times the ring diameter. New magnitudes for polar ring galaxies are presented. 2) a search, in a wider field, for galaxies of similar size that may have encountered the polar ring host galaxy in a time of the order of 1 Gyr. Differently from the results of similar searches in the fields of active galaxies, the environment of the Polar Ring Galaxies seems to be similar to that of normal galaxies.This result may give support to the models suggesting long times for formation and evolution of the rings. If the rings are old (and stable or in equilibrium), no traces of the past interaction are expected in their surroundings. In addition, the formation of massive polar rings, too big to derive from the ingestion of a present-day dwarf galaxy, may be easily placed in epochs with a higher number of gas-rich galaxies.Comment: Accepted for publication in Astron. Astrophys. Main Journal, 9 pages including 3 postscript figure

La Educación a Distancia ¿es una opción para las Universidades?

Nadie pone en duda el hecho de que desde hace aproximadamente tres décadas asistimos a profundas transformaciones en los paradigmas políticos, sociales, culturales y científicos- tecnológicos. Hoy se demanda trabajadores más especializados que dediquen más horas a su labor pero que a su vez se capaciten constantemente. Las propuestas educativas en modalidad a distancia se constituyen como una valiosísima oportunidad para muchas personas ya que la flexibilidad es una de las características más destacada de esta modalidad. Ante esta realidad se demanda a las Universidades que se adaptan a este nuevo contexto social, cultural, económico, político y tecnológico; y que a su vez den respuesta a esta demanda de capacitación que le realiza la sociedad. Por ello es necesario que se piense a la Educación a Distancia en entornos virtuales de la misma manera que la oferta presencial, como algo inherente a la Universidad. Esto va a permitir el desarrollo de dos cuestiones importantes: 1.- Brindar a la sociedad la posibilidad de acceder a capacitación; 2.- Que la oferta con modalidad a distancia sea de calidad. En el marco de este plateo se describe además, el proceso de generación y desarrollo del Programa de Educación a Distancia de la UN

Preliminary analysis of distributed in situ soil moisture measurements

Surface soil moisture content is highly variable in both space and time. Remote sensing can provide an effective methodology for mapping surface moisture content over large areas but ground based measurements are required to test its reliability and to calibrate retrieval algorithms. Recently, we had the opportunity to design and perform an experiment aimed at jointly acquiring measurements of surface soil water content at various locations and remotely sensed hyperspectral data. The area selected for the experiment is located in central Umbria and it extends for 90km². For the area, detailed lithological and multi-temporal landslide inventory maps were available. We identified eight plots where measurements of soil water content were made using a Time Domain Reflectometer (TDR). The plots range in size from 100m² to 600m², and cover a variety of topographic and morphological settings. The TDR measurements were conducted during four days, on 5 April, 15 April, 2 May and 3 May 2004. On 3 May the NERC airborne CASI 2 acquired the hyperspectral data. Preliminary analysis concerning the matching between the landslides and the soil moisture were reported. Statistical and geostatistical analysis investigating the spatial-temporal soil moisture distribution were performed. These results will be compared with the data of surface temperature obtained from the remotely sensed hyperspectral sensor

A Broad Search for Counterrotating Gas and Stars: Evidence for Mergers and Accretion

We measure the frequency of bulk gas-stellar counterrotation in a sample of 67 galaxies drawn from the Nearby Field Galaxy Survey, a broadly representative survey of the local galaxy population down to M_B-15. We detect 4 counterrotators among 17 E/S0's with extended gas emission (24% +8 -6). In contrast, we find no clear examples of bulk counterrotation among 38 Sa-Sbc spirals, although one Sa does show peculiar gas kinematics. This result implies that, at 95% confidence, no more than 8% of Sa-Sbc spirals are bulk counterrotators. Among types Sc and later, we identify only one possible counterrotator, a Magellanic irregular. We use these results together with the physical properties of the counterrotators to constrain possible origins for this phenomenon.Comment: 19 pages, 4 figures, AJ, accepte

Esquemes emocionals en un grup de pacients depressius d'un hospital de la ciutat de Lima

En el present treball, el coneixement dels esquemes emocionals en pacients deprimits permet identificar les creences que tenen sobre les emocions, pensaments erronis sobre aquestes, i estarien presents en reaccions emocionals i comportaments que afecten al benestar psicològic de les persones. En aquesta línia, es va aplicar l’escala d’esquemes emocionals de Leahy, la qual consta de 50 preguntes, en una mostra de 80 pacients adults diagnosticats amb depressió, en un hospital de salut mental. Es van realitzar la validesa lingüística, la de contingut i la convergent de la prova, i es van calcular la mitjana dels factors de les variables d’estudi. A continuació, es va procedir a realitzar la correlació de Pearson entre els qüestionaris LESS i el BDI-II per comprovar la validesa convergent del primer. Es conclou que el qüestionari LESS compta amb els paràmetres de validesa necessaris, i es replica allò esclarit per Leahy (2002). Els resultats indiquen que no existeixen diferències significatives segons edat. Segons gènere, existeixen diferències significatives als esquemes de validació, comprensió i expressió, i son les dones qui en manifesten una mitjana més alta en comparació amb els homes

Proyecto de Tutorías de Pares : una propuesta innovadora para el ingreso y permanencia universitaria.

La Facultad de Ciencias Exactas Físicas y Naturales de la UNC esta desarrollando el Proyecto Tutorias de Pares, orientado a los alumnos de los primeros años de todas las carreras de ingeniería. Apunta a favorecer la integración del alumnado en el proceso de inclusión al ámbito universitario y a acompañarlo en el desarrollo de una metodología de aprendizaje acorde a las exigencias de los estudios superiores. Este proyecto es de carácter innovador ya que consiste en un sistema de tutoría de pares en la que estudiantes avanzados en la carrera acompañan y orientan a alumnos de los primeros años, guiados a su vez por Docentes Tutores, siendo el Gabinete Psicopedagógico el encargado de capacitar a los tutores y coordinar la implementación del proyecto. Este trabajo intenta relatar los conflictos en la implementación, los ajustes y las acciones realizadas en conjunto, revelando de qué modo algunas problemáticas pretendieron resolverse según fueron emergiendo. Se muestra como se propicia a través del proyecto el desarrollo, en futuros egresados, de competencias y habilidades sociales (comunicación, organización, resolución de problemas, etc.) necesarias para su labor profesional, logrando así que los beneficiarios sean tanto los alumnos ingresantes, como los tutores alunos

Decoration of nanovesicles with pH (low) insertion peptide (pHLIP) for targeted delivery

Acidity at surface of cancer cells is a hallmark of tumor microenvironments, which does not depend on tumor perfusion, thus it may serve as a general biomarker for targeting tumor cells. We used the pH (low) insertion peptide (pHLIP) for decoration of liposomes and niosomes. pHLIP senses pH at the surface of cancer cells and inserts into the membrane of targeted cells, and brings nanomaterial to close proximity of cellular membrane. DMPC liposomes and Tween 20 or Span 20 niosomes with and without pHLIP in their coating were fully characterized in order to obtain fundamental understanding on nanocarrier features and facilitate the rational design of acidity sensitive nanovectors. The samples stability over time and in presence of serum was demonstrated. The size, ζ-potential, and morphology of nanovectors, as well as their ability to entrap a hydrophilic probe and modulate its release were investigated. pHLIP decorated vesicles could be useful to obtain a prolonged (modified) release of biological active substances for targeting tumors and other acidic diseased tissues

AM 1934-563: A giant spiral polar-ring galaxy in a triplet

We have observed the emission-line kinematics and photometry of a southern triplet of galaxies. The triplet contains a giant spiral galaxy AM 1934-563 which optical structure resembles a polar-ring galaxy: distorted spiral disk, seen almost edge-on, and a faint large-scale (45 kpc in diameter) warped structure, inclined by 60^o-70^o with respect to the disk major axis. The triplet shows relatively small velocity dispersion (69 km/s) and a large crossing time (0.17 in units of the Hubble time). The disk of AM 1934-563 demonstrates optical colors typical for an early-type spirals, strong radial color gradient, and almost exponential surface brightness distribution with an exponential scale-length value of 3.1 kpc (R passband). The galaxy shows a maximum rotation velocity of about 200 km/s and it lies close to the Tully-Fisher relation for spiral galaxies. The suspected polar ring is faint (\mu(B) > 24) and strongly warped. Its total luminosity comprises (10-15)% of the total luminosity of AM 1934-563. We then try to model this system using numerical simulations, and study its possible formation mechanisms. We find that the most robust model, that reproduces the observed characteristics of the ring and the host galaxy, is the tidal transfer of mass from a massive gas-rich donor galaxy to the polar ring. The physical properties of the triplet of galaxies are in agreement with this scenario.Comment: Accepted for publication in A&

UGC 7388: a galaxy with two tidal loops

We present the results of spectroscopic and morphological studies of the galaxy UGC7388 with the 8.1-m Gemini North telescope. Judging by its observed characteristics, UGC7388 is a giant late-type spiral galaxy seen almost edge-on. The main body of the galaxy is surrounded by two faint (\mu(B) ~ 24 and \mu(B) ~ 25.5) extended (~20-30 kpc) loop-like structures. A large-scale rotation of the brighter loop about the main galaxy has been detected. We discuss the assumption that the tidal disruption of a relatively massive companion is observed in the case of UGC7388. A detailed study and modeling of the observed structure of this unique galaxy can give important information about the influence of the absorption of massive companions on the galactic disks and about the structure of the dark halo around UGC7388.Comment: 8 pages, 5 figure

Prognostic significance of human pituitary tumor-transforming gene immunohistochemical expression in differentiated thyroid cancer

Context: Human securin pituitary tumor-transforming gene (hPTTG) is overexpressed in a variety of primary neoplasias, including differentiated thyroid cancer (DTC). Objective: The objective of this study was to examine the immunohistochemical expression of hPTTG in DTC and its association with known prognostic factors. Design: hPTTG expression was analyzed by immunostaining on paraffin-embedded tissues. Clinical data were used to determine any associations between the expression of hPTTG and prognostic variables of DTC. A median follow-up of 43 months allowed us to analyze the persistence of disease and the response to radioiodine therapy. Setting: The study was conducted at a tertiary university hospital. Patients: Ninety-five patients undergoing surgical resection for DTC (n = 60) or benign nodular thyroid disease (n = 35) were studied. Main Outcome Measure: The main outcome measure was the association between hPTTG expression and prognostic factors in DTC. Results: Among DTC cases, 21 (35%) had low and 39 (65%) had high hPTTG immunostaining. Adjacent nonneoplastic thyroid tissue was largely unstained. Among benign nodular thyroid disease cases, immunostaining was detected focally in eight (22.8%). A significant association was found between hPTTG expression and the presence of nodal (P < 0.01) or distant metastases (P < 0.05). A significant association with TNM was also found, because 83.3% of advanced TNM stages showed elevated hPTTG (P < 0.05). The association between hPTTG overexpression and decreased radioiodine uptake during follow-up was also significant (P < 0.05). The expression levels of hPTTG were confirmed as an independent prognostic factor for persistent disease (relative risk, 3.0; 95% confidence interval, 1.1-8.7; P < 0.05). Conclusions: Immunohistochemical analysis of hPTTG is of potential value in the determination of tumor aggressiveness in DTC.Peer Reviewe