228 research outputs found
El valor del bosque : las aventuras de Tui y Kerekere en los rÃos del Chaco
El agua es el recurso más importante para los seres humanos y organismos vivos del planeta. En la naturaleza se la puede encontrar de diversas formas y en distintos lugares. La observamos en las nubes del cielo, en la nieve de las montañas, en el rocÃo y niebla de la mañana, y recorriendo las vertientes que nacen en nuestros bosques y montañas. Las aventuras de Tui y Kerekere "El valor del bosque" es la segunda de cuatro historias educativas desarrolladas por la Fundación Amigos de la Naturaleza en el marco del Proyecto "Balance HÃdrico, Calidad Biológica y Gestión del Agua en la parte Sub-andina del Chaco Boliviano" en su componente de Ciencia Participativa, que busca dar a conocer a los niños y jóvenes de un modo sencillo y comprensible a cerca de los componentes de la gestión y cuidado del agua. Este material está dirigido a niños, profesores y pobladores del Chaco, es una guÃa de aprendizaje y sensibilización hacia los recursos hÃdricos
Conociendo el ciclo del agua : las aventuras de Tui y Kerekere en los rÃos del Chaco
El agua es el recurso más importante para los seres humanos y organismos vivos del planeta. En la naturaleza se la puede encontrar de diversas formas y en distintos lugares. La observamos en las nubes del cielo, en la nieve de las montañas, en el rocÃo y niebla de la mañana, y recorriendo las vertientes que nacen en nuestros bosques y montañas. Las aventuras de Tui y Kerekere "Conociendo el ciclo del agua" es la primera de cuatro historias educativas desarrolladas por la Fundación Amigos de la Naturaleza en el marco del Proyecto "Balance HÃdrico, Calidad Biológica y Gestión del Agua en la parte Sub-andina del Chaco Boliviano" en su componente de Ciencia Participativa, que busca dar a conocer a los niños y jóvenes de un modo sencillo y comprensible a cerca de los componentes de la gestión y cuidado del agua. Este material está dirigido a niños, profesores y pobladores del Chaco, es una guÃa de aprendizaje y sensibilización hacia los recursos hÃdricos
Stable accretion and episodic outflows in the young transition disk system GM Aurigae
We investigate the structure and dynamics of the magnetospheric accretion
region and associated outflows on a scale smaller than 0.1 au around the young
transitional disk system GM Aur. We monitored the variability of the system on
timescales ranging from days to months, using high-resolution optical and
near-infrared spectroscopy, multiwavelength photometry, and low-resolution
near-infrared spectroscopy, over a total duration of six months (30 rotational
cycles). We analyzed the photometric and line profile variability to
characterize the accretion and ejection processes. The luminosity of the system
is modulated by surface spots at the stellar rotation period of 6.04 days. The
Balmer, Paschen, and Brackett hydrogen lines as well as the HeI 5876 A and HeI
10830 A line profiles are modulated on the same period. The PaB line flux
correlates with the photometric excess in the u' band, which suggests that most
of the line emission originates from the accretion process. High-velocity
redshifted absorptions reaching below the continuum periodically appear in the
near-infrared line profiles at the rotational phase in which the veiling and
line fluxes are the largest. These are signatures of a stable accretion funnel
flow and associated accretion shock at the stellar surface. This large-scale
magnetospheric accretion structure appears fairly stable over at least 15 and
possibly up to 30 rotational periods. In contrast, outflow signatures randomly
appear as blueshifted absorption components in the Balmer and HeI 10830 A line
profiles and disappear on a timescale of a few days. The coexistence of a
stable, large-scale accretion pattern and episodic outflows supports
magnetospheric ejections as the main process occurring at the star-disk
interface. Stable magnetospheric accretion and episodic outflows appear to be
physically linked on a scale of a few stellar radii in this system.Comment: 30 pages, 28 figures, 12 tables, accepted for publication in
Astronomy & Astrophysic
MUC1 expression and anti-MUC1 serum immune response in head and neck squamous cell carcinoma (HNSCC): a multivariate analysis
BACKGROUND: HNSCC progression to adjacent tissue and nodes may be mediated by altered glycoproteins and glycolipids such as MUC1 mucin. This report constitutes a detailed statistical study about MUC1 expression and anti-MUC1 immune responses in relation to different clinical and pathological parameters which may be useful to develop new anti HNSCC therapeutic strategies. PATIENTS AND METHODS: Fifty three pre treatment HNSCC patients were included: 26 (49.1%) bearing oral cavity tumors, 17 (32.1%) localized in the larynx and 10 (18.8%) in the pharynx. Three patients (5.7%) were at stage I, 5 (9.4%) stage II, 15 (28.3%) stage III and 30 (56.6%) at stage IV. MUC1 tumor expression was studied by immunohistochemistry employing two anti-MUC1 antibodies: CT33, anti cytoplasmic tail MUC1 polyclonal antibody (Ab) and C595 anti-peptidic core MUC1 monoclonal antibody. Serum levels of MUC1 and free anti-MUC1 antibodies were detected by ELISA and circulating immune complexes (CIC) by precipitation in polyethylene glycol (PEG) 3.5%; MUC1 isolation from circulating immune complexes was performed by protein A-sepharose CL-4B affinity chromatography followed by SDS-PAGE and Western blot. Statistical analysis consisted in Multivariate Principal Component Analysis (PCA); ANOVA test (Tukey's test) was employed to find differences among groups; nonparametrical correlations (Kendall's Tau) were applied when necessary. Statistical significance was set to p < 0.05 in all cases. RESULTS: MUC1 cytoplasmic tail was detected in 40/50 (80%) and MUC1 protein core in 9/50 (18%) samples while serum MUC1 levels were elevated in 8/53 (15%) patients. A significant statistical correlation was found between MUC1 serum levels and anti-MUC1 IgG free antibodies, while a negative correlation between MUC1 serum levels and anti-MUC1 IgM free antibodies was found. Circulating immune complexes were elevated in 16/53 (30%) samples and were also statistically associated with advanced tumor stage. MUC1 was identified as an antigenic component of IgG circulating immune complexes. Moreover, poorly differentiated tumors were inversely correlated with tumor and serum MUC1 detection and positively correlated with node involvement and tumor mass. CONCLUSION: Possibly, tumor cells produce MUC1 mucin which is liberated to the circulation and captured by IgG antibodies forming MUC1-IgG-CIC. Another interesting conclusion is that poorly differentiated tumors are inversely correlated with tumor and serum MUC1 detection
Humoral immune response to MUC5AC in patients with colorectal polyps and colorectal carcinoma
BACKGROUND: MUC5AC is a secreted mucin aberrantly expressed by colorectal polyps and carcinoma. It has been hypothesized that aberrant expression of MUC5AC in colorectal carcinoma tissues increased the overall survival of patients with colorectal carcinoma. The present study investigates the incidence of naturally occurring MUC5AC antibodies in the sera of normal individuals, patients with colonic polyps and patients with advanced colorectal carcinoma. A second aim was to determine the relationship of MUC5AC antibody with the prognosis of colorectal carcinoma. METHODS: Free circulating MUC5AC antibodies were measured using an enzyme-linked immunosorbent assay with a synthetic peptide corresponding to an 8 aa. segment of MUC5AC tandem repeat region. Immunohistochemical analysis was completed to demonstrate MUC5AC expression in the polyp specimens. RESULTS: MUC5AC antibodies were detected in 6 of 22 (27.3%) healthy subjects, 9 of 20 (45%) polyp patients, 18 of 30 (60%) patients with colorectal cancer. The presence of circulating free MUC5AC antibody levels was significantly correlated with expression of MUC5AC in polyp sections. Serum MUC5AC antibody positivity was higher in patients with colon located tumors, advanced stage and poorly differentiated tumors were found negatively affecting patient survival in our study. MUC5AC antibody positivity was higher in patients with poor prognostic parameters. Disease free survival and overall survival were shorter in this group of patients. In the multivariate analysis MUC5AC antibody positivity didn't find an independent prognostic factor on prognosis. CONCLUSION: Decreased survival in colorectal carcinoma patients with MUC5AC antibody positivity may be due to a decrease in the MUC5AC expression in tumor tissues of surviving carcinoma patients
Catálogo de los peces de la cuenca Iténez (Bolivia y Brasil)
Se presenta una lista de los peces de la cuenca Iténez elaborada en base a descripciones taxonómicas originales, registros bibliográficos y estudios recientes de investigadores de Brasil y Bolivia. Las especies fueron seleccionadas considerando cinco criterios de acuerdo con la confiabilidad de la fuente de referencia. Las citas de los taxones fueron acompañadas por observaciones vinculadas a su nomenclatura, distribución geográfica conocida y su registro para la cuenca Iténez. En total, 619 taxones de peces están citadas en la literatura. De estas, 556 especies fueron reconocidas como válidas y 63 tienen identificación incompleta o representan identificaciones dudosas debido a la incompatibilidad entre su área de distribución conocida y su presencia en la cuenca del rÃo Iténez.E apresentada urna lista de espécies de peixes da bacia Iténez*, elaborada com base em descrigóes originais para a mesma, registros bibliográficos e estudos recentes realizados por pesquisadores do Brasil e BolÃvia. As espécies foram selecionadas considerando cinco critérios relacionados à veracidade de sua fonte de referencia. As citagóes dos táxons foram acompanhadas por observagóes vinculadas á nomenclatura, à distribuigao conhecida do táxon e ao seu registro na bacia Iténez. Um total de 619 espécies de peixes foram registradas. Destas, 556 espécies foram identificadas como válidas e 63 táxons foram indicados com identificagao incerta ou foram consideradas duvidosas devido à s divergencias entre a distribuigao geográfica conhecida para os taxons na literatura recente e seu registro na bacia Iténez.* Iténez e denominado rio Guaporé no Brasil.A check list of the fish species of the Iténez* river basin was compiled on the basis of original species descriptions, main references and recent studies by Bolivian and Brazilian researchers. The species list was based on five criteria ordered according to the reliability of the reference. The citations of taxa were followed by notes on the nomenclature or the divergences between the generally accepted distribution of each taxon and its ocurrence in the Iténez river basin. In total, 619 fish species were recorded in the literature. Of these, 556 species were categorized as valid. Sixty three citations were considered doubtful due to uncertain identification or incompatibility between their original known geographical distribution range and their records in the Iténez river basin.* The Iténez river is known as Guaporé river in Brasil
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