317 research outputs found

    Phospho-kinase profile of triple negative breast cancer and androgen receptor signaling

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    BACKGROUND: The androgen receptor (AR) plays a central role in the oncogenesis of different tumors, as is the case in prostate cancer. In triple negative breast cancer (TNBC) a gene expression classification has described different subgroups including a luminal androgen subtype. The AR can be controlled by several mechanisms like the activation of membrane tyrosine kinases and downstream signaling pathways. However little is known in TNBC about how the AR is modulated by these mechanisms and the potential therapeutic strategists to inhibit its expression. METHODS: We used human samples to evaluate the expression of AR by western-blot and phospho-proteomic kinase arrays that recognize membrane tyrosine kinase receptors and downstream mediators. Western-blots in human cell lines were carried out to analyze the expression and activation of individual proteins. Drugs against these kinases in different conditions were used to measure the expression of the androgen receptor. PCR experiments were performed to assess changes in the AR gene after therapeutic modulation of these pathways. RESULTS: AR is present in a subset of TNBC and its expression correlates with activated membrane receptor kinases-EGFR and PDGFRβ in human samples and cell lines. Inhibition of the PI3K/mTOR pathway in TNBC cell lines decreased notably the expression of the AR. Concomitant administration of the anti-androgen bicalutamide with the EGFR, PDGFRβ and Erk1/2 inhibitors, decreased the amount of AR compared to each agent given alone, and had an additive anti-proliferative effect. Administration of dihydrotestosterone augmented the expression of AR that was not modified by the inhibition of the PI3K/mTOR or Erk1/2 pathways. AR expression was posttranscriptionally regulated by PI3K or Erk1/2 inhibition. CONCLUSION: Our results describe the expression of the AR in TNBC as a druggable target and further suggest the combination of bicalutamide with inhibitors of EGFR, PDGFRβ or Erk1/2 for future development

    Validity and reliability of the new Basic Functional Assessment protocol (BFA)

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    The global evaluation of motion patterns can examine the synchrony of neuromuscular control, range of motion, strength, resistance, balance and coordination needed to complete the movement. Visual assessments are commonly used to detect risk factors. However, it is essential to define standardized field-based tests that can evaluate with accuracy. The aims of the study were to design a protocol to evaluate fundamental motor patterns (FMP), and to analyze the validity and reliability of an instrument created to provide information about the quality of movement in FMP. Five tasks were selected: Overhead Squat (OHS); Hurdle Step (HS); Forward Step Down (FSD); Shoulder Mobility (SM); Active Stretching Leg Raise (ASLR). A list of variables was created for the evaluation of each task. Ten qualified judges assessed the validity of the instrument, while six external observers performed inter-intra reliability. The results show that the instrument is valid according to the experts’ opinion; however, the reliability shows values below those established. Thus, the instrument was considered unreliable, so it is recommended to repeat the reliability process by performing more training sessions for the external observers. The present study creates the basic functional assessment (BFA), a new protocol which comprises five tasks and an instrument to evaluate FMP

    Stellar populations of galaxies in the ALHAMBRA survey up to z1z \sim 1. II. Stellar content of quiescent galaxies within the dust-corrected stellar mass-colour and the UVJUVJ colour-colour diagrams

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    Our aim is to determine the distribution of stellar population parameters (extinction, age, metallicity, and star formation rate) of quiescent galaxies within the rest-frame stellar mass-colour and UVJUVJ colour-colour diagrams corrected for extinction up to z1z\sim1. These novel diagrams reduce the contamination in samples of quiescent galaxies owing to dust-reddened galaxies, and they provide useful constraints on stellar population parameters. We set constraints on the stellar population parameters of quiescent galaxies combining the ALHAMBRA multi-filter photo-spectra with our SED-fitting code MUFFIT, making use of composite stellar population models. The extinction obtained by MUFFIT allowed us to remove dusty star-forming (DSF) galaxies from the sample of red UVJUVJ galaxies. The distributions of stellar population parameters across these rest-frame diagrams are revealed after the dust correction and are fitted by the LOESS method to reduce uncertainty effects. Quiescent galaxy samples defined via classical UVJUVJ diagrams are typically contaminated by a 20\sim20% fraction of DSF galaxies. A significant part of the galaxies in the green valley are actually obscured star-forming galaxies (3065\sim30-65%). Consequently, the transition of galaxies from the blue cloud to the red sequence, and hence the related mechanisms for quenching, seems to be much more efficient and faster than previously reported. The rest-frame stellar mass-colour and UVJUVJ colour-colour diagrams are useful for constraining the age, metallicity, extinction, and star formation rate of quiescent galaxies by only their redshift, rest-frame colours, and/or stellar mass. Dust correction plays an important role in understanding how quiescent galaxies are distributed in these diagrams and is key to performing a pure selection of quiescent galaxies via intrinsic colours.Comment: (37 pages, 29 figures, accepted for publication in A&A

    The ALHAMBRA survey: evolution of galaxy spectral segregation

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    We study the clustering of galaxies as a function of spectral type and redshift in the range 0.35<z<1.10.35 < z < 1.1 using data from the Advanced Large Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) survey. The data cover 2.381 deg2^2 in 7 fields, after applying a detailed angular selection mask, with accurate photometric redshifts [σz<0.014(1+z)\sigma_z < 0.014(1+z)] down to IAB<24I_{AB} < 24. From this catalog we draw five fixed number density, redshift-limited bins. We estimate the clustering evolution for two different spectral populations selected using the ALHAMBRA-based photometric templates: quiescent and star-forming galaxies. For each sample, we measure the real-space clustering using the projected correlation function. Our calculations are performed over the range [0.03,10.0]h1[0.03,10.0] h^{-1} Mpc, allowing us to find a steeper trend for rp0.2h1r_p \lesssim 0.2 h^{-1} Mpc, which is especially clear for star-forming galaxies. Our analysis also shows a clear early differentiation in the clustering properties of both populations: star-forming galaxies show weaker clustering with evolution in the correlation length over the analysed redshift range, while quiescent galaxies show stronger clustering already at high redshifts, and no appreciable evolution. We also perform the bias calculation where similar segregation is found, but now it is among the quiescent galaxies where a growing evolution with redshift is clearer. These findings clearly corroborate the well known colour-density relation, confirming that quiescent galaxies are mainly located in dark matter halos that are more massive than those typically populated by star-forming galaxies.Comment: 14 pages, 9 figures, accepted by Ap

    Comparison of fiber effect on glycemic index and glycemic load in differents types of bread

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    Indexación: Scopus; Redalyc.Existen diversos alimentos que contienen como nutriente principal hidratos de carbono, destacando entre ellos el pan por su masivo consumo a nivel mundial. Numerosos estudios se han llevado a cabo con el fin de reducir su índice glicémico, sin embargo, aún existe controversia sobre la acción de la fibra dietética en la disminución del IG en este alimento. Este estudio determinó el efecto de la fibra dietética sobre el índice glicémico y carga glicémica en dos tipos de panes comerciales en 23 individuos sanos quienes consumieron aleatoriamente 3 diferentes productos, de 50 g de carbohidratos cada uno, durante 6 días: pan blanco (PH), pan integral (PF), y solución glucosada como producto de referencia (SG). Se midió glicemia en ayunas y post-prandial a los tiempos 15, 30, 45, 60, 90 y 120 min. La insulina fue medida en el minuto 0 y 120 min. El área bajo la curva de glicemia resultó más baja para ambos tipos de pan PH 13589 ±1557, PF 12005 ±1254 que para el producto de referencia SG 14089 ±1245. Los valores del índice glicémico PH 68,55 ±1,2 y PF 62,10 ±1,3 y carga glicémica PH 16,45 ±1,4 resultaron más bajos para el pan con mayor aporte de fibra 9,93 ± 1,1, sin diferencias en la concentración de insulina, sugiriendo que la cantidad de carbohidratos y tipo de fibra contenidos en el pan integral, pueden considerarse factores intrínsecos en su composición nutricional, capaces de afectar la respuesta glicémica post- ingesta de estos productos en individuos sanos.There are several foods that contain carbohydrates as the main nutrient, being one of the most important the bread for its massive worldwide consumption. Numerous studies have been done in order to reduce its glycemic index, however there is still controversy about the action of dietary fiber in the decrease of GI in this product. In this study, it was determined the effect of dietetic fiber on glycemic index and glycemic load in two types of commercial breads in 23 healthy individuals who randomly consumed 3 different products during 6 days of 50g of carbohydrates each: white bread (PH), whole wheat bread (PE) and glucose solution as reference product (SG). Fasting and postprandial glycemia was measured at times 15, 30, 45, 60, 90 and 120 minutes. Insuline was measured at 0 min and 120 min. The area under de glycemia curve was lower for both bread types PH 13589 ±1557, PF 12005 ±1254 than for the reference product SG 14089 ±1245. The values of the glycemic index PH 68,55 ±1,2 and PF 62,01 ±1,3 and glycemic load PH 16.45 ±1,4 were lower for bread with more amount fiber 9,93 ± 1,1, with no difference in insulin concentration, suggesting that the amount of carbohydrates and fiber type contained in whole wheat bread can be considered intrinsic factors in bread composition, affecting the post-intake glycemic response of this type of products in healthy individuals.http://www.redalyc.org/articulo.oa?id=5594990800

    The ALHAMBRA survey: Accurate merger fractions by PDF analysis of photometric close pairs

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    Our goal is to develop and test a novel methodology to compute accurate close pair fractions with photometric redshifts. We improve the current methodologies to estimate the merger fraction f_m from photometric redshifts by (i) using the full probability distribution functions (PDFs) of the sources in redshift space, (ii) including the variation in the luminosity of the sources with z in both the selection of the samples and in the luminosity ratio constrain, and (iii) splitting individual PDFs into red and blue spectral templates to deal robustly with colour selections. We test the performance of our new methodology with the PDFs provided by the ALHAMBRA photometric survey. The merger fractions and rates from the ALHAMBRA survey are in excellent agreement with those from spectroscopic work, both for the general population and for red and blue galaxies. With the merger rate of bright (M_B <= -20 - 1.1z) galaxies evolving as (1+z)^n, the power-law index n is larger for blue galaxies (n = 2.7 +- 0.5) than for red galaxies (n = 1.3 +- 0.4), confirming previous results. Integrating the merger rate over cosmic time, we find that the average number of mergers per galaxy since z = 1 is N_m = 0.57 +- 0.05 for red galaxies and N_m = 0.26 +- 0.02 for blue galaxies. Our new methodology exploits statistically all the available information provided by photometric redshift codes and provides accurate measurements of the merger fraction by close pairs only using photometric redshifts. Current and future photometric surveys will benefit of this new methodology.Comment: Submitted to A&A, 15 pages, 15 figures, 6 tables. Comments are welcome. Close pair systems available at https://cloud.iaa.csic.es/alhambra/catalogues/ClosePairs

    High redshift galaxies in the ALHAMBRA survey: I. selection method and number counts based on redshift PDFs

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    Context. Most observational results on the high redshift restframe UV-bright galaxies are based on samples pinpointed using the so called dropout technique or Ly-alpha selection. However, the availability of multifilter data allows now replacing the dropout selections by direct methods based on photometric redshifts. In this paper we present the methodology to select and study the population of high redshift galaxies in the ALHAMBRA survey data. Aims. Our aim is to develop a less biased methodology than the traditional dropout technique to study the high redshift galaxies in ALHAMBRA and other multifilter data. Thanks to the wide area ALHAMBRA covers, we especially aim at contributing in the study of the brightest, less frequent, high redshift galaxies. Methods. The methodology is based on redshift probability distribution functions (zPDFs). It is shown how a clean galaxy sample can be obtained by selecting the galaxies with high integrated probability of being within a given redshift interval. However, reaching both a complete and clean sample with this method is challenging. Hence, a method to derive statistical properties by summing the zPDFs of all the galaxies in the redshift bin of interest is introduced. Results. Using this methodology we derive the galaxy rest frame UV number counts in five redshift bins centred at z=2.5, 3.0, 3.5, 4.0, and 4.5, being complete up to the limiting magnitude at m_UV(AB)=24. With the wide field ALHAMBRA data we especially contribute in the study of the brightest ends of these counts, sampling well the surface densities down to m_UV(AB)=21-22. Conclusions. We show that using the zPDFs it is easy to select a clean sample of high redshift galaxies. We also show that statistical analysis of the properties of galaxies is better done using a probabilistic approach, which takes into account both the incompleteness and contamination in a natural way.Comment: 16 pages, 11 figures; Accepted for A&A; language correcte

    The ALHAMBRA survey : BB-band luminosity function of quiescent and star-forming galaxies at 0.2z<10.2 \leq z < 1 by PDF analysis

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    Our goal is to study the evolution of the BB-band luminosity function (LF) since z=1z=1 using ALHAMBRA data. We used the photometric redshift and the II-band selection magnitude probability distribution functions (PDFs) of those ALHAMBRA galaxies with I24I\leq24 mag to compute the posterior LF. We statistically studied quiescent and star-forming galaxies using the template information encoded in the PDFs. The LF covariance matrix in redshift-magnitude-galaxy type space was computed, including the cosmic variance. That was estimated from the intrinsic dispersion of the LF measurements in the 48 ALHAMBRA sub-fields. The uncertainty due to the photometric redshift prior is also included in our analysis. We modelled the LF with a redshift-dependent Schechter function affected by the same selection effects than the data. The measured ALHAMBRA LF at 0.2z<10.2\leq z<1 and the evolving Schechter parameters both for quiescent and star-forming galaxies agree with previous results in the literature. The estimated redshift evolution of MBQzM_B^* \propto Qz is QSF=1.03±0.08Q_{\rm SF}=-1.03\pm0.08 and QQ=0.80±0.08Q_{\rm Q}=-0.80\pm0.08, and of logϕPz\log \phi^* \propto Pz is PSF=0.01±0.03P_{\rm SF}=-0.01\pm0.03 and PQ=0.41±0.05P_{\rm Q}=-0.41\pm0.05. The measured faint-end slopes are αSF=1.29±0.02\alpha_{\rm SF}=-1.29\pm0.02 and αQ=0.53±0.04\alpha_{\rm Q}=-0.53\pm0.04. We find a significant population of faint quiescent galaxies, modelled by a second Schechter function with slope β=1.31±0.11\beta=-1.31\pm0.11. We find a factor 2.55±0.142.55\pm0.14 decrease in the luminosity density jBj_B of star-forming galaxies, and a factor 1.25±0.161.25\pm0.16 increase in the jBj_B of quiescent ones since z=1z=1, confirming the continuous build-up of the quiescent population with cosmic time. The contribution of the faint quiescent population to jBj_B increases from 3% at z=1z=1 to 6% at z=0z=0. The developed methodology will be applied to future multi-filter surveys such as J-PAS.Comment: Accepted for publication in Astronomy and Astrophysics. 25 pages, 20 figures, 7 table

    The ALHAMBRA survey : Estimation of the clustering signal encoded in the cosmic variance

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    The relative cosmic variance (σv\sigma_v) is a fundamental source of uncertainty in pencil-beam surveys and, as a particular case of count-in-cell statistics, can be used to estimate the bias between galaxies and their underlying dark-matter distribution. Our goal is to test the significance of the clustering information encoded in the σv\sigma_v measured in the ALHAMBRA survey. We measure the cosmic variance of several galaxy populations selected with BB-band luminosity at 0.35z<1.050.35 \leq z < 1.05 as the intrinsic dispersion in the number density distribution derived from the 48 ALHAMBRA subfields. We compare the observational σv\sigma_v with the cosmic variance of the dark matter expected from the theory, σv,dm\sigma_{v,{\rm dm}}. This provides an estimation of the galaxy bias bb. The galaxy bias from the cosmic variance is in excellent agreement with the bias estimated by two-point correlation function analysis in ALHAMBRA. This holds for different redshift bins, for red and blue subsamples, and for several BB-band luminosity selections. We find that bb increases with the BB-band luminosity and the redshift, as expected from previous work. Moreover, red galaxies have a larger bias than blue galaxies, with a relative bias of brel=1.4±0.2b_{\rm rel} = 1.4 \pm 0.2. Our results demonstrate that the cosmic variance measured in ALHAMBRA is due to the clustering of galaxies and can be used to characterise the σv\sigma_v affecting pencil-beam surveys. In addition, it can also be used to estimate the galaxy bias bb from a method independent of correlation functions.Comment: Astronomy and Astrophysics, in press. 9 pages, 4 figures, 3 table
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