333 research outputs found
The BINGO Project: III. Optical design and optimization of the focal plane
Context. The Baryon Acoustic Oscillations from Integrated Neutral Gas Observations (BINGO) telescope was designed to measure the fluctuations of the 21 cm radiation arising from the hyperfine transition of neutral hydrogen. It is also aimed at measuring the baryon acoustic oscillations (BAO) from such fluctuations, thereby serving as a pathfinder to future, deeper intensity mapping surveys. The requirements for the Phase 1 of the projects consider a large reflector system (two 40 m-class dishes in a crossed-Dragone configuration) illuminating a focal plane with 28 horns to measure the sky, with two circular polarizations in a drift scan mode to produce measurements of the radiation in intensity (I) as well as the circular (V) polarization. Aims. In this paper, we present the optical design for the instrument. We describe the optical arrangement of the horns in the focal plane to produce a homogeneous and well-sampled map after the end of Phase 1, as well as the intensity and polarization properties of the beams. Our analysis provides an optimal model for the location of the horns in the focal plane, producing a homogeneous and Nyquist-sampled map after the nominal survey time. Methods. We used the GRASP package to model the focal plane arrangement and performed several optimization tasks to arrive at the current configuration, including an estimation of the sidelobes corresponding to the diffraction patterns of the two mirrors. The final model for the focal plane was defined through a combination of neural network and other direct optimization methods. Results. We arrived at an optimal configuration for the optical system that includes the focal plane positioning and the beam behavior of the instrument. We present an estimate of the expected sidelobes both for intensity and polarization, as well as the effect of band averaging on the final sidelobes, as well as an estimation of the cross-polarization leakage for the final configuration. Conclusions. We conclude that the chosen optical design meets the requirements for the project in terms of polarization purity and area coverage as well as a homogeneity of coverage so that BINGO can perform a successful BAO experiment. We further conclude that the requirements on the placement and rms error on the mirrors are also achievable so that a successful experiment can be conducted
The BINGO project: I. Baryon acoustic oscillations from integrated neutral gas observations
Context. Observations of the redshifted 21-cm line of neutral hydrogen (HI) are a new and powerful window of observation that offers us the possibility to map the spatial distribution of cosmic HI and learn about cosmology. Baryon Acoustic Oscillations from Integrated Neutral Gas Observations (BINGO) is a new unique radio telescope designed to be one of the first to probe baryon acoustic oscillations (BAO) at radio frequencies. Aims. BINGO has two science goals: cosmology and astrophysics. Cosmology is the main science goal and the driver for BINGO's design and strategy. The key of BINGO is to detect the low redshift BAO to put strong constraints on the dark sector models and test the ICDM (cold dark matter) model. Given the versatility of the BINGO telescope, a secondary goal is astrophysics, where BINGO can help discover and study fast radio bursts (FRB) and other transients, as well as study Galactic and extragalactic science. In this paper, we introduce the latest progress of the BINGO project, its science goals, describing the scientific potential of the project for each goal and the new developments obtained by the collaboration. Methods. BINGO is a single dish transit telescope that will measure the BAO at low-z by making a 3D map of the HI distribution through the technique of intensity mapping over a large area of the sky. In order to achieve the project's goals, a science strategy and a specific pipeline for cleaning and analyzing the produced maps and mock maps was developed by the BINGO team, which we generally summarize here. Results. We introduce the BINGO project and its science goals and give a general summary of recent developments in construction, science potential, and pipeline development obtained by the BINGO Collaboration in the past few years. We show that BINGO will be able to obtain competitive constraints for the dark sector. It also has the potential to discover several FRBs in the southern hemisphere. The capacity of BINGO in obtaining information from 21-cm is also tested in the pipeline introduced here. Following these developments, the construction and observational strategies of BINGO have been defined. Conclusions. There is still no measurement of the BAO in radio, and studying cosmology in this new window of observations is one of the most promising advances in the field. The BINGO project is a radio telescope that has the goal to be one of the first to perform this measurement and it is currently being built in the northeast of Brazil. This paper is the first of a series of papers that describe in detail each part of the development of the BINGO project
Mestrado Profissional em Saúde Pública: do marco legal à experiência em uma instituição de pesquisa e ensino
A cost effective fermentative production of glutathione by Saccharomyces cerevisiae with cane molasses and glycerol
Monossialogangliosídeo transdérmico com laser no tratamento de lesão medular espinal de ratos
Acute kidney injury in a tropical country: a cohort study of 253 patients in an infectious diseases intensive care unit
Proteomic profiling of Burkholderia cenocepacia clonal isolates with different virulence potential retrieved from a cystic fibrosis patient during chronic lung infection
Respiratory infections with Burkholderia cepacia complex (Bcc) bacteria in cystic fibrosis (CF) are associated with a worse prognosis and increased risk of death. In this work, we assessed the virulence potential of three B. cenocepacia clonal isolates obtained from a CF patient between the onset of infection (isolate IST439) and before death with cepacia syndrome 3.5 years later (isolate IST4113 followed by IST4134), based on their ability to invade epithelial cells and compromise epithelial monolayer integrity. The two clonal isolates retrieved during late-stage disease were significantly more virulent than IST439. Proteomic profiling by 2-D DIGE of the last isolate recovered before the patient's death, IST4134, and clonal isolate IST439, was performed and compared with a prior analysis of IST4113 vs. IST439. The cytoplasmic and membrane-associated enriched fractions were examined and 52 proteins were found to be similarly altered in the two last isolates compared with IST439. These proteins are involved in metabolic functions, nucleotide synthesis, translation and protein folding, cell envelope biogenesis and iron homeostasis. Results are suggestive of the important role played by metabolic reprogramming in the virulence potential and persistence of B. cenocepacia, in particular regarding bacterial adaptation to microaerophilic conditions. Also, the content of the virulence determinant AidA was higher in the last 2 isolates. Significant levels of siderophores were found to be secreted by the three clonal isolates in an iron-depleted environment, but the two late isolates were more tolerant to low iron concentrations than IST439, consistent with the relative abundance of proteins involved in iron uptake.This work was supported by FEDER and FCT – Fundação para a Ciência e a Tecnologia (contract PEst-OE/EQB/LA0023/2011_ research line: Systems and Synthetic Biology; PhD grant to A.M. – SFRH/BD/37012/2007, and PD grants to S.S. – SFRH/BPD/75483/2010 and C.C. – SFRH/BPD/ 81220/2011. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.info:eu-repo/semantics/publishedVersio
Population structure of Uncancylus concentricus (d'Orbigny, 1835) (Ancylidae, Pulmonata, Basommatophora) in the Multiple Use Reserve Martín García Island, Upper Río de la Plata, Argentina
- …