The PLATO 2.0 mission

PLATO 2.0 has recently been selected for ESA's M3 launch opportunity (2022/24). Providing accurate key planet parameters (radius, mass, density and age) in statistical numbers, it addresses fundamental questions such as: How do planetary systems form and evolve? Are there other systems with planets like ours, including potentially habitable planets? The PLATO 2.0 instrument consists of 34 small aperture telescopes (32 with 25 s readout cadence and 2 with 2.5 s candence) providing a wide field-of-view (2232 deg 2) and a large photometric magnitude range (4-16 mag). It focusses on bright (4-11 mag) stars in wide fields to detect and characterize planets down to Earth-size by photometric transits, whose masses can then be determined by ground-based radial-velocity follow-up measurements. Asteroseismology will be performed for these bright stars to obtain highly accurate stellar parameters, including masses and ages. The combination of bright targets and asteroseismology results in high accuracy for the bulk planet parameters: 2 %, 4-10 % and 10 % for planet radii, masses and ages, respectively. The planned baseline observing strategy includes two long pointings (2-3 years) to detect and bulk characterize planets reaching into the habitable zone (HZ) of solar-like stars and an additional step-and-stare phase to cover in total about 50 % of the sky. PLATO 2.0 will observe up to 1,000,000 stars and detect and characterize hundreds of small planets, and thousands of planets in the Neptune to gas giant regime out to the HZ. It will therefore provide the first large-scale catalogue of bulk characterized planets with accurate radii, masses, mean densities and ages. This catalogue will include terrestrial planets at intermediate orbital distances, where surface temperatures are moderate. Coverage of this parameter range with statistical numbers of bulk characterized planets is unique to PLATO 2.0. The PLATO 2.0 catalogue allows us to e.g.: - complete our knowledge of planet diversity for low-mass objects, - correlate the planet mean density-orbital distance distribution with predictions from planet formation theories,- constrain the influence of planet migration and scattering on the architecture of multiple systems, and - specify how planet and system parameters change with host star characteristics, such as type, metallicity and age. The catalogue will allow us to study planets and planetary systems at different evolutionary phases. It will further provide a census for small, low-mass planets. This will serve to identify objects which retained their primordial hydrogen atmosphere and in general the typical characteristics of planets in such low-mass, low-density range. Planets detected by PLATO 2.0 will orbit bright stars and many of them will be targets for future atmosphere spectroscopy exploring their atmosphere. Furthermore, the mission has the potential to detect exomoons, planetary rings, binary and Trojan planets. The planetary science possible with PLATO 2.0 is complemented by its impact on stellar and galactic science via asteroseismology as well as light curves of all kinds of variable stars, together with observations of stellar clusters of different ages. This will allow us to improve stellar models and study stellar activity. A large number of well-known ages from red giant stars will probe the structure and evolution of our Galaxy. Asteroseismic ages of bright stars for different phases of stellar evolution allow calibrating stellar age-rotation relationships. Together with the results of ESA's Gaia mission, the results of PLATO 2.0 will provide a huge legacy to planetary, stellar and galactic science

Yield and carcass composition of broilers fed with diets based on the concept of crude protein or ideal protein

Two experiments were conducted to evaluate the effect of diets formulated using the criteria of crude protein (CP) and ideal protein (IP) on the yield and carcass composition of male and female broilers. Birds of two broilers strains (Hybro G and Hybro PG) were reared from 1 to 42 days of age during the summer, with average temperatures of 26°C. A completely randomized experimental design was used in a 2 x 2 factorial arrangement, with 6 replicates and 20 birds per pen. On day 42, four birds from each experimental unit were killed and carcass yield and composition were determined. Breast yield was higher in males and females fed the IP-based diet than in birds fed the CP-based diet. Abdominal fat pad and carcass crude protein were statistically similar between the two protein criteria and between strains. Carcass amino acid levels evidenced higher levels of Met, Lys, Met+Cys and Thr in the males fed IP-based diets. No differences were seen between the two criteria for the females. Diets formulated according to IP resulted in better carcass and breast yield, both for males and females

Detection and molecular characterization of group A rotavirus from hospitalized children in Rio de Janeiro, Brazil, 2004

Rotavirus is a major cause of infantile acute diarrhea, causing about 440,000 deaths per year, mainly in developing countries. The World Health Organization has been recommending the assessment of rotavirus burden and strain characterization as part of the strategies of immunization programs against this pathogen. In this context, a prospective study was made on a sample of 134 children with acute diarrhea and severe dehydration admitted to venous fluid therapy in two state hospitals in Rio de Janeiro, Brazil, from February to September 2004. Rotavirus where detected by polyacrylamide gel electrophoresis (PAGE) and by an enzyme-linked immunoassay to rotavirus and adenovirus (EIARA) in 48% of the children. Positive samples for group A rotavirus (n = 65) were analyzed by reverse transcription/heminested multiplex polymerase chain reaction to determine the frequency of G and [P] genotypes and, from these, 64 samples could be typed. The most frequent G genotype was G1 (58%) followed by G9 (40%). One mixed infection (G1/G9) was detected. The only [P] genotype identified was [8]. In order to estimate the rotavirus infection frequency in children who acquired diarrhea as hospital infection in those hospitals, we studied 24 patients, detecting the pathogen in 41% of them. This data suggest that genotype G9 is an important genotype in Rio de Janeiro, with implications to the future strategies of vaccination against rotavirus, reinforcing the need of continuous monitoring of circulating strains of the pathogen, in a surveillance context

Biological Control of Postharvest Diseases by Microbial Antagonists

The postharvest phase has been considered a very suitable environment for successful application of biological control agents (BCAs), since the first work on the biological control of brown rot disease of stone fruit was reported by Pusey and Wilson [1]. Sure enough, the conditions of constant temperature and high humidity seem to offer more chances to BCAs, increasing their antifungal activity [2]. BCAs are living organisms and act following different antagonistic strategies depending on pathogens, host and environment. Knowledge of their modes of action is therefore essential to enhance their viability and increase their potentiality in disease control. In general, antagonists used for biocontrol of postharvest diseases are yeasts and bacteria, and to a lesser extent fungi, and they have been widely reviewed [3\u20137]. Antagonists can display a wide range of modes of action, at different stages of their activity, relating to different hosts, pathogens; sometimes-different modes act simultaneously, and it is therefore difficult to establish which individual mechanism has contributed to a specific antifungal action. Considerable information is available with respect to their efficacy, their application under storage conditions, and their mixture with safe substances or according to the formulation. However, the mechanisms by which BCAs exert their activity against pathogens have not yet been fully elucidated [5] and sometimes, in order to achieve maximum effectiveness in postharvest phase, were combined with physical and chemical methods including heat treatments, gamma or UV-C irradiation, and controlled atmosphere (CA). The bottleneck of the biocontrol matter remains the BCAs formulation often done in association with private companies, due to the high costs of production and the regulatory barriers to BCAs registration in different countries that often do not encourage their dissemination. Also, a formulation often could reduce the activity of antagonists with respect to the fresh cells [2]

Biological Control of Postharvest Diseases by Microbial Antagonists

The postharvest phase has been considered a very suitable environment for successful application of biological control agents (BCAs), since the first work on the biological control of brown rot disease of stone fruit was reported by Pusey and Wilson [1]. Sure enough, the conditions of constant temperature and high humidity seem to offer more chances to BCAs, increasing their antifungal activity [2]. BCAs are living organisms and act following different antagonistic strategies depending on pathogens, host and environment. Knowledge of their modes of action is therefore essential to enhance their viability and increase their potentiality in disease control. In general, antagonists used for biocontrol of postharvest diseases are yeasts and bacteria, and to a lesser extent fungi, and they have been widely reviewed [3–7]. Antagonists can display a wide range of modes of action, at different stages of their activity, relating to different hosts, pathogens; sometimes-different modes act simultaneously, and it is therefore difficult to establish which individual mechanism has contributed to a specific antifungal action. Considerable information is available with respect to their efficacy, their application under storage conditions, and their mixture with safe substances or according to the formulation. However, the mechanisms by which BCAs exert their activity against pathogens have not yet been fully elucidated [5] and sometimes, in order to achieve maximum effectiveness in postharvest phase, were combined with physical and chemical methods including heat treatments, gamma or UV-C irradiation, and controlled atmosphere (CA). The bottleneck of the biocontrol matter remains the BCAs formulation often done in association with private companies, due to the high costs of production and the regulatory barriers to BCAs registration in different countries that often do not encourage their dissemination. Also, a formulation often could reduce the activity of antagonists with respect to the fresh cells [2]