2,001 research outputs found
Forming first-ranked early-type galaxies through hierarchical dissipationless merging
We have developed a computationally competitive N-body model of a
previrialized aggregation of galaxies in a flat LambdaCDM universe to assess
the role of the multiple mergers that take place during the formation stage of
such systems in the configuration of the remnants assembled at their centres.
An analysis of a suite of 48 simulations of low-mass forming groups (of about
1E13 solar masses) demonstrates that the gravitational dynamics involved in
their hierarchical collapse is capable of creating realistic first-ranked
galaxies without the aid of dissipative processes. Our simulations indicate
that the brightest group galaxies (BGGs) constitute a distinct population from
other group members, sketching a scenario in which the assembly path of these
objects is dictated largely by the formation of their host system. We detect
significant differences in the distribution of Sersic indices and total
magnitudes, as well as a luminosity gap between BGGs and the next brightest
galaxy that is positively correlated with the total luminosity of the parent
group. Such gaps arise from both the grow of BGGs at the expense of lesser
companions and the decrease in the relevance of second-ranked objects in equal
measure. This results in a dearth of intermediate-mass galaxies which explains
the characteristic central dip detected in their luminosity functions in
dynamically young galaxy aggregations. The fact that the basic global
properties of our BGGs define a thin mass fundamental plane strikingly similar
to that followed giant early-type galaxies in the local universe reinforces
confidence in the results obtained.Comment: 25 pages, 14 figures, 3 tables. Accepted to MNRA
Optimizing CIGB-300 intralesional delivery in locally advanced cervical cancer
Background:We conducted a phase 1 trial in patients with locally advanced cervical cancer by injecting 0.5 ml of the CK2-antagonist CIGB-300 in two different sites on tumours to assess tumour uptake, safety, pharmacodynamic activity and identify the recommended dose.Methods:Fourteen patients were treated with intralesional injections containing 35 or 70 mg of CIGB-300 in three alternate cycles of three consecutive days each before standard chemoradiotherapy. Tumour uptake was determined using 99 Tc-radiolabelled peptide. In situ B23/nucleophosmin was determined by immunohistochemistry.Results:Maximum tumour uptake for CIGB-300 70-mg dose was significantly higher than the one observed for 35 mg: 16.1±8.9 vs 31.3±12.9 mg (P=0.01). Both, AUC 24h and biological half-life were also significantly higher using 70 mg of CIGB-300 (P<0.001). Unincorporated CIGB-300 diffused rapidly to blood and was mainly distributed towards kidneys, and marginally in liver, lungs, heart and spleen. There was no DLT and moderate allergic-like reactions were the most common systemic side effect with strong correlation between unincorporated CIGB-300 and histamine levels in blood. CIGB-300, 70 mg, downregulated B23/nucleophosmin (P=0.03) in tumour specimens.Conclusion:Intralesional injections of 70 mg CIGB-300 in two sites (0.5 ml per injection) and this treatment plan are recommended to be evaluated in phase 2 studies.Fil: Sarduy, M. R.. Medical-surgical Research Center; CubaFil: García, I.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Coca, M. A.. Clinical Investigation Center; CubaFil: Perera, A.. Clinical Investigation Center; CubaFil: Torres, L. A.. Clinical Investigation Center; CubaFil: Valenzuela, C. M.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Baladrón, I.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Solares, M.. Hospital Materno Ramón González Coro; CubaFil: Reyes, V.. Center For Genetic Engineering And Biotechnology Havana; CubaFil: Hernández, I.. Isotope Center; CubaFil: Perera, Y.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Martínez, Y. M.. Medical-surgical Research Center; CubaFil: Molina, L.. Medical-surgical Research Center; CubaFil: González, Y. M.. Medical-surgical Research Center; CubaFil: Ancízar, J. A.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Prats, A.. Clinical Investigation Center; CubaFil: González, L.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Casacó, C. A.. Clinical Investigation Center; CubaFil: Acevedo, B. E.. Centro de Ingeniería Genética y Biotecnología; CubaFil: López Saura, P. A.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Alonso, Daniel Fernando. Universidad Nacional de Quilmes; ArgentinaFil: Gómez, R.. Elea Laboratories; ArgentinaFil: Perea Rodríguez, S. E.. Center For Genetic Engineering And Biotechnology Havana; Cuba. Centro de Ingeniería Genética y Biotecnología; Cub
Estudio descriptivo retrospectivo de la fractura de cadera en un área de salud de la Comunidad Valenciana
Se presenta un estudio descriptivo de la fractura de cadera osteoporótica en el área de Salud 20 de la Comunidad Valenciana durante el año 2007. Se incluyó una serie consecutiva de 239 pacientes que sufrieron fractura de fémur proximal. Se diseñó una base de datos recogiendo información clínica como la edad, sexo, tipo de fractura y lateralidad, antecedentes personales, datos referidos al accidente, al ingreso y estancia, así como al tratamiento.A descriptive study of osteoporotic hip fracture in the Health area 20 of the Valencian Community in 2007. We included a consecutive series of 239 patients undergoing proximal femoral fracture. We created a database collecting clinical information such as age, sex, type of fracture and handedness, personal history, referred to the accident data, entry and stay, and treatment
The night-sky at the Calar Alto Observatory II: The sky at the near infrared
We present here the characterization of the night sky-brightness at the
near-infrared, the telescope seeing, and the fraction of useful time at the
Calar Alto observatory. For this study we have collected a large dataset
comprising 7311 near-infrared images taken regularly along the last four years
for the ALHAMBRA survey (J, H and Ks-bands), together with a more reduced
dataset of additional near-infrared images taken for the current study. In
addition we collected the information derived by the meteorological station at
the observatory during the last 10 years, together with the results from the
cloud sensor for the last ~2 years. We analyze the dependency of the
near-infrared night sky-brightness with the airmass and the seasons, studying
its origins and proposing a zenithal correction. A strong correlation is found
between the night sky-brightness in the Ks-band and the air temperature, with a
gradient of ~ -0.08 mag per 1 C degree. The typical (darkest) night
sky-brightness in the J, H and Ks-band are 15.95 mag (16.95 mag), 13.99 mag
(14.98 mag) and 12.39 mag (13.55 mag), respectively. These values show that
Calar Alto is as dark in the near-infrared as most of the other astronomical
astronomical sites in the world that we could compare with. Only Mauna Kea is
clearly darker in the Ks-band. The typical telescope seeing at the 3.5m is
~1.0" when converted to the V-band, being only slightly larger than the
atmospheric seeing measured at the same time by the seeing monitor, ~0.9".
Finally we estimate the fraction of useful time based on the relative humidity,
gust wind speed and presence of clouds. This fraction, ~72%, is very similar to
the one derived in Paper I, based on the fraction of time when the extinction
monitor is working.Comment: 15 pages, 6 figures, accepted to be published in PAS
Spitzer Infrared Spectrograph Observations of Magellanic Cloud Planetary Nebulae: the nature of dust in low metallicity circumstellar ejecta
We present 5 - 40 micron spectroscopy of 41 planetary nebulae (PNe) in the
Magellanic Clouds, observed with the Infrared Spectrograph on board the Spitzer
Space Telescope. The spectra show the presence of a combination of nebular
emission lines and solid-state features from dust, superimposed on the thermal
IR continuum.
By analyzing the 25 LMC and 16 SMC PNe in our sample we found that the IR
spectra of 14 LMC and 4 SMC PNe are dominated by nebular emission lines, while
the other spectra show solid-state features. We observed that the solid-state
features are compatible with carbon-rich dust grains (SiC, polycyclic aromatic
hydrocarbons (PAHs), etc.) in most cases, except in three PNe showing
oxygen-rich dust features. The frequency of carbonaceous dust features is
generally higher in LMC than in SMC PNe.
The spectral analysis allowed the correlations of the dust characteristics
with the gas composition and morphology, and the properties of the central
stars. We found that: 1) all PNe with carbonaceous dust features have C/O>1,
none of these being bipolar or otherwise highly asymmetric; 2) all PNe with
oxygen-rich dust features have C/O<1, with probable high mass progenitors if
derived from single-star evolution (these PNe are either bipolar or highly
asymmetric); 3) the dust temperature tracks the nebular and stellar evolution;
and 4) the dust production efficiency depends on metallicity, with low
metallicity environments not favoring dust production.Comment: The Astrophysical Journal, in pres
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Supply-chain modelling and control under proportional inventory-replenishment policies
A novel state-space model of a multi-node supply chain is presented, controlled via local proportional inventory-replenishment policies. The model is driven by a stochastic sequence representing customer demand. The model is analysed under stationarity conditions and a simple recursive scheme is developed for updating its covariance matrix. This allows us to characterise the ‘bullwhip effect’ (demand amplification) in the chain and to solve an optimisation problem for a three-node model involving the minimisation of inventory subject to a probabilistic constraint on downstream demand. Finally, issues related to estimation schemes based on local historical data are briefly discussed
Potential use of pyriproxyfen for control of Aedes aegypti (Diptera: Culicidae) in Iquitos, Peru
Los efectos del pyriproxyfen fueron evaluados contra una población local de Aedes aegypti (L.) en Iquitos, Perú. Los bioensayos mostraron que el pyriproxyfen previene la emergencia de adultos con concentraciones extremadamente bajas (LC50 = 0,012 ppb). No hubo emergencia de adultos de las muestras de agua obtenidas de los tanques de almacenamiento que habían sido tratados con el equivalente de 50-83 ppb (AI) de pyriproxyfen. Cinco meses después del tratamiento, a pesar de las constantes diluciones de estos tanques, las muestras de agua de estas fuentes continuaron siendo letales para las larvas y pupa
On the role of the upper part of words in lexical access : evidence with masked priming
More than 100 years ago, Huey (1908) indicated that the upper part of words was more relevant for perception than the lower part. Here we examined whether mutilated words, in their upper/lower portions (e.g., , , , ), can automatically access their word units in the mental lexicon. To that end, we conducted four masked repetition priming experiments with the lexical decision task. Results showed that mutilated primes produced a sizeable masked repetition priming effect. Furthermore, the magnitude of the masked repetition priming effect was greater when the upper part of the primes was preserved than when the lower portion was preserved –this was the case not only when the mutilated words were presented in lowercase but also when the mutilated words were presented in uppercase. Taken together, these findings suggest that the front-end of computational models of visual-word recognition should be modified to provide a more realistic account at the level of letter features.The research reported in this article has been partially supported by Grant PSI2008-04069/PSIC and CONSOLIDER-INGENIO2010 CSD2008-00048 from the Spanish Ministry of Science and Innovation and by Grant PTDC/PSI-PCO/104671/2008 from the Portuguese Foundation for Science and Technology
Insulin Resistance and Gray Matter Volume in Neurodegenerative Disease
The goal of this study was to compare insulin resistance in aging and aging-related neurodegenerative diseases, and to determine the relationship between insulin resistance and gray matter volume (GMV) in each cohort using an unbiased, voxel-based approach. Insulin resistance was estimated in apparently healthy elderly control (HC, n = 21) and neurodegenerative disease (Alzheimer’s disease (AD), n = 20; Parkinson’s disease (PD), n = 22) groups using Homeostasis Model Assessment of Insulin Resistance 2 (HOMA2) and intravenous glucose tolerance test (IVGTT). HOMA2 and GMV were assessed within groups through General Linear Model multiple regression. We found that HOMA2 was increased in both AD and PD compared to the HC group (HC vs. AD, p = 0.002, HC vs. PD, p = 0.003), although only AD subjects exhibited increased fasting glucose (p = 0.005). Furthermore, our voxel-based morphometry analysis revealed that HOMA2 was related to GMV in all cohorts in a region-specific manner (p < 0.001, uncorrected). Significant relationships were observed in the medial prefrontal cortex (HC), medial temporal regions (AD), and parietal regions (PD). Finally, the directionality of the relationship between HOMA2 and GMV was disease-specific. Both HC and AD subjects exhibited negative relationships between HOMA2 and brain volume (increased HOMA2 associated with decreased brain volume), while a positive relationship was observed in PD. This cross-sectional study suggests that insulin resistance is increased in neurodegenerative disease, and that individuals with AD appear to have more severe metabolic dysfunction than individuals with PD or PD dementia
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