350 research outputs found
Searching for compact radio sources associated to UCHII regions
Ultra-Compact (UC)HII regions represent a very early stage of massive star
formation whose structure and evolution are not yet fully understood.
Interferometric observations in recent years show that some UCHII regions have
associated compact sources of uncertain nature. Based on this, we carried out
VLA 1.3 cm observations in the A configuration of selected UCHII regions in
order to report additional cases of compact sources embedded in UCHII regions.
From the observations, we find 13 compact sources associated to 9 UCHII
regions. Although we cannot establish an unambiguous nature for the newly
detected sources, we assess some of their observational properties. According
to the results, we can distinguish between two types of compact sources. One
type corresponds to sources that probably are deeply embedded in the dense
ionized gas of the UCHII region. These sources are being photo-evaporated by
the exciting star of the region and will last for 10 yr. They may play
a crucial role in the evolution of the UCHII region as the photo-evaporated
material could replenish the expanding plasma and might provide a solution to
the so-called lifetime problem for these regions. The second type of compact
sources is not associated with the densest ionized gas of the region. A few of
these sources appear resolved and may be photo-evaporating objects such as
those of the first type but with significantly lower mass depletion rates. The
rest of sources of this second type appear unresolved and their properties are
varied. We speculate on the similarity between the sources of the second type
and those of the Orion population of radio sources.Comment: 33 pages, 6 figures, 4 tables. Accepted for publication in Ap
Biomasa de raíces finas en arreglos agroforestales con cacao en la amazonia occidental colombiana
Los arreglos agroforestales con cacao poseen una estructura diversificada, la cual influye sobre el comportamiento de las raíces finas, cuya distribución está influenciada por las diferentes prácticas culturales. El objetivo del presente trabajo fue estudiar la distribución, el aporte de biomasa de raíces finas en relación con la densidad aparente y el porcentaje de humedad en arreglos agroforestales con cacao en el Centro de Investigaciones CIMAZ Macagual (1°37’LN y 75°36’LO). El muestreo se desarrolló en tres arreglos agroforestales con cacao clasificados en sombra intensa, semisombra y pleno sol. Para la extracción de la biomasa de raíces se utilizó el cilindro de volumen conocido cada 10cm hasta llegar a 1m de profundidad. Las raíces finas fueron extraídas a través de una malla de un tamaño <2mm. Se presentaron diferencias estadísticas significativas entre la interacción arreglo-profundidad para la variable biomasa de raíces (<0,001) con una correlación positiva (0,26) entre el peso y la densidad aparente. La mayor acumulación de biomasa de raíces se presentó entre los primeros 20cm de profundidad en los tres sistemas estudiados, donde la densidad aparente aumenta en los diferentes perfiles del suelo; a su vez la humedad gravimétrica fue mayor en los arreglos agroforestales que en cacao a pleno sol, mostrando diferencias significativas (P<0,001) con una correlación negativa (-0,75) en cuanto a las profundidades. En este sentido, los sistemas agroforestales favorecen la disponibilidad de agua en los primeros perfiles del suelo aumentando la presencia de raíces finas
Editorial: Research on emotion and learning: contributions from Latin America
Latin America has increased its share of world scientific publications by nearly twofold during the last two decades (approximately from 2 to 4%). Despite this positive trend, the scholarly impact of scientific research produced in the region - measured in terms of citation rate - remains low. Two interrelated factors that contribute to this situation is that most research groups tend to work in isolation or in local sporadic collaboration, and results are often published in journals that are not indexed in major citation databases (e.g., SCOPUS, or Web of Science). Ultimately, part of Latin American high-quality research seems to remain hidden from the rest of the world. Over the last decades, an important number of Latin American scientists have developed fruitful research agendas on questions on learning and emotion, focusing on basic and/or translational research with humans and other animal models, and implementing diverse methodologies. Notwithstanding the important contributions of these research programs, Latin American research on emotion and learning has followed the overall trend of other research fields throughout the region; namely, remaining partially hidden from the large scientific community of the world. This Research Topic aimed to engage researchers from Latin America to share their empirical and conceptual work on learning and emotion. Ultimately, this effort was expected to strengthen and integrate our regional community of experts, enhance global networking, and establish new challenges and developments for future investigation.Fil: Hurtado Parrado, Camilo. Fundación Universitaria Konrad Lorenz; ColombiaFil: Gantiva, Carlos. Universidad de Los Andes; VenezuelaFil: Gómez A., Alexander. University of North Carolina; Estados UnidosFil: Cuenya, Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Médicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Ortega, Leonardo. Fundación Universitaria Konrad Lorenz; ColombiaFil: Rico, Javier L.. Fundación Universitaria Konrad Lorenz; Colombi
Anthropometric Values in Spanish Elite Soccer: Differences between Divisions and Playing Positions
Body composition is an important factor in a soccer player’s performance, and anthropometry is one of the most widely used methods of measurement. The physical demands of Spanish soccer have evolved over time, so the ideal body composition requirements must be adapted to the present day. The aim of this study was to describe the anthropometric and body composition profiles of professional soccer players in the second, second B, and third divisions during the 2019–2020 season in order to compare the anthropometric parameters of players among positions and competitive divisions. A cross-sectional study was conducted to determine differences in kinanthropometric and derived variables in a sample of Spanish soccer players. A total of 615 soccer players from the second (116 players), second B (310 players), and third (189 players) divisions participated in this study. After comparing the groups according to the playing position and category, it was observed that at higher levels of play, soccer players show lower values of fat mass (FM) and higher values of muscle mass (MM) and bone mass (BM); at lower levels of play, soccer players show more anthropometric differences between playing positions. Lastly, the somatotype of the elite soccer player is balanced mesomorphic, with higher levels of mesomorphy at higher levels of play. In summary, this is the first study to evaluate the body composition of the different Spanish soccer divisions
-Variational autoencoders and transformers for reduced-order modelling of fluid flows
Variational autoencoder (VAE) architectures have the potential to develop
reduced-order models (ROMs) for chaotic fluid flows. We propose a method for
learning compact and near-orthogonal ROMs using a combination of a -VAE
and a transformer, tested on numerical data from a two-dimensional viscous flow
in both periodic and chaotic regimes. The -VAE is trained to learn a
compact latent representation of the flow velocity, and the transformer is
trained to predict the temporal dynamics in latent space. Using the -VAE
to learn disentangled representations in latent-space, we obtain a more
interpretable flow model with features that resemble those observed in the
proper orthogonal decomposition, but with a more efficient representation.
Using Poincar\'e maps, the results show that our method can capture the
underlying dynamics of the flow outperforming other prediction models. The
proposed method has potential applications in other fields such as weather
forecasting, structural dynamics or biomedical engineering
Ultracompact HII regions with extended emission: The complete view
\ua9 2019 The Author(s). In this paper, we present the results of a morphological study performed on a sample of 28 ultracompact HII (UC HII) regions located near extended free-free emission, using radio continuum (RC) observations at 3.6 cm with the C and D Very Large Array (VLA) configurations, with the aim of determining a direct connection between them. By using previously published observations in B and D VLA configurations, we compiled a final catalogue of 21 UC HII regions directly connected with the surrounding extended emission (EE). The observed morphology of most of the UC HII regions in RC emission is irregular (single- or multipeaked sources) and resembles a classical bubble structure in the Galactic plane with well-defined cometary arcs. RC images superimposed on colour composite Spitzer images reinforce the assignations of direct connection by the spatial coincidence between the UC components and regions of saturated 24 μm emission. We also find that the presence of EE may be crucial to understand the observed infrared excess because an underestimation of ionizing Lyman photons was considered in previous works (e.g. Wood & Churchwell; Kurtz, Churchwell & Wood)
Metastatic breast cancer patients treated with low-dose metronomic chemotherapy with cyclophosphamide and celecoxib: clinical outcomes and biomarkers of response
Background
Preclinical results showing therapeutic effect and low toxicity of metronomic chemotherapy with cyclophosphamide (Cy) + celecoxib (Cel) for mammary tumors encouraged its translation to the clinic for treating advanced breast cancer patients (ABCP).
Patients and methods
A single-arm, mono-institutional, non-randomized, phase II, two-step clinical trial (approved by Bioethics Committee and Argentine Regulatory Authority) was designed. Patients received Cy (50 mg po.d) + Cel (200 mg p.o.bid). Patient eligibility criteria included: ABCP who progressed to anthracyclines, taxanes and capecitabine, ≤4 chemotherapy schemes, with good performance status. Several pro- and anti-angiogenic molecules and cells were determined as biomarkers. Informed consent was signed by all patients. Primary endpoint was clinical benefit (CB).
Results
Twenty patients were enrolled. Main clinical outcomes were prolonged disease stabilization and partial remission in 10/20 and 1/20 patients, respectively. CB was 55 %, and time to progression (TTP) was 21.1 weeks. Median TTP in patients who achieved CB was 35.6 weeks, and mean overall survival was 44.20 weeks. There were no grade 3/4 toxicities associated with treatment. Circulating endothelial cells (CECs) increased at the time of progression in patients who showed CB (P = 0.014). Baseline CECs and circulating endothelial progenitor cells showed marginal associations with TTP. Serum VEGF decreased (P = 0.050), sVEGFR-2 increased (P = 0.005) and VEGF/sVEGFR-2 ratio decreased during treatment (P = 0.041); baseline VEGF and VEGF/sVEGFR-2 were associated with TTP (P = 0.035 and P = 0.030, respectively), while sVEGFR-2 did not.
Conclusions
Treatment was effective, showing low toxicity profile and excellent tolerability. The combination had anti-angiogenic effect. Increased levels of CEC could be useful for detecting progression. Baseline VEGF and VEGF/sVEGFR-2 values could be useful as early predictors of response.
Trial registration
ANMAT#4596/09.Fil: Perroud, Herman A. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; ArgentinaFil: Alasino, Carlos María. Institute of Oncology of Rosario; ArgentinaFil: Rico, María José. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; ArgentinaFil: Mainetti, Leandro Ernesto. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; ArgentinaFil: Queralt, Francisco. Institute of Oncology of Rosario; ArgentinaFil: Pezzotto, Stella Maris. Research Council of the National University of Rosario (CIUNR); ArgentinaFil: Rozados, Viviana R. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; ArgentinaFil: Scharovsky, O. Graciela. Universidad Nacional de Rosario. Consejo de Investigaciones UNR, Facultad de Ciencias Médicas; Argentin
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