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Transgenic chickens have been generated from blastodermal chimeric chickens created by an injection of the foreign DNA-transfected blastodermal cells into recipient embryos. However, there has been no method that allows the efficient foreign DNA transfection into chicken primary cells without using viral vectors. This method using viral vectors has a limitation on the size of DNA that can be transfected, and homologous recombination is not possible with this method. This study was conducted to establish a DNA transfection method using electroporation, which can transfect up to 5 kb DNAs into cells. Embryos at stage X were obtained from freshly laid eggs (200) of Barred Plymouth Rock chickens. Blastodermal cells (105 cells) were then collected from them and transfected with the linearized EGFP or YFP gene by electroporation using a Nucleofector Device (Amaxa, Inc., Gaithersburg, MD, USA). After transfection, the transfected chicken blastodermal cells were injected into White Leghorn recipient embryos to produce chimeric chickens. By 48 h after gene transfection, EGFP or YFP gene expression in the cells was easily observed under a fluorescence microscope. The gene expression rate, however, could not be determined, because the cultured chicken blastodermal cells were not able to separate and it was impossible to load them on the flow cytometer to determine the rate. The blastodermal cells transfected with the EGFP or YFP gene were cultured over night and injected into recipient embryos. The manipulated embryos were cultured ex ovo until they hatched. Dead embryos before hatch were dissected and observed under the fluorescence microscope to determine whether they had fluorescent organs. EGFP or YFP gene expression was detected at several areas: head, somite, inner tissues, and limb bud of embryos, but not germinal tissues. Six female chicks and 10 male chicks were obtained. Five females and 6 males were raised until they were sexually mature. Five female chickens were artificially inseminated with semen of Barred Plymouth Rock males to obtain progeny from donor transfected cells. However, no progeny was obtained. Thus the contribution of donor cells to the germ cells could not be determined, and it was not clear if the expression of EGFP gene or YFP gene was stable. Furthermore, semen could not be collected from six males because of a technical problem, and males were not mated. Although a large number of cells must be used to transfect a foreign gene, the novel gene transfer method in chicken in this study has great significance in the field of transgenic chicken production. Even if the gene expression is transient, this transfer method will enable us not only to integrate more than 5 kb DNA into the avian genome but also to induce homologous recombination in cultured avian cells. [ABSTRACT FROM AUTHOR]

Abstract  The LHCf experiment will be installed in 2007 on the LHC collider in the forward direction at ±140m from the ATLAS interaction point. The purpose of LHCf is to precisely measure the pion production cross section near zero degrees through the measurement of the photons produced in neutral pion decay. This measurement is crucial for the simulation of the showers induced in the atmosphere by very high energy cosmic rays; the 14 TeV energy available in the center of mass frame corresponds in fact to an equivalent energy of 1017 eV in the laboratory system. The paper focus on the proposed experiment and on the physics results that we expect from it. [ABSTRACT FROM AUTHOR]

We report the results of the statistical analysis of planetary signals discovered in MOA-II microlensing survey alert system events from 2007 to 2012. We determine the survey sensitivity as a function of planet–star mass ratio, q, and projected planet–star separation, s, in Einstein radius units. We find that the mass-ratio function is not a single power law, but has a change in slope at q ∼ 10−4, corresponding to ∼20 M⊕ for the median host-star mass of ∼0.6 . We find significant planetary signals in 23 of the 1474 alert events that are well-characterized by the MOA-II survey data alone. Data from other groups are used only to characterize planetary signals that have been identified in the MOA data alone. The distribution of mass ratios and separations of the planets found in our sample are well fit by a broken power-law model of the form for q > qbr and for q < qbr, where qbr is the mass ratio of the break. We also combine this analysis with the previous analyses of Gould et al. and Cassan et al., bringing the total sample to 30 planets. This combined analysis yields , n = −0.93 ± 0.13, , and for qbr ≡ 1.7 × 10−4. The unbroken power-law model is disfavored with a p-value of 0.0022, which corresponds to a Bayes factor of 27 favoring the broken power-law model. These results imply that cold Neptunes are likely to be the most common type of planets beyond the snow line. [ABSTRACT FROM AUTHOR]

We report the discovery of a planet by the microlensing method, OGLE-2012-BLG-0724Lb. Although the duration of the planetary signal for this event was one of the shortest seen for a planetary event, the anomaly was well covered thanks to high-cadence observations taken by the survey groups OGLE and MOA. By analyzing the light curve, this planetary system is found to have a mass ratio . By conducting a Bayesian analysis, we estimate that the host star is an M dwarf with a mass of located at away from the Earth and the companion’s mass is . The projected planet–host separation is . Because the lens–source relative proper motion is relatively high, future high-resolution images would detect the lens host star and determine the lens properties uniquely. This system is likely a Saturn-mass exoplanet around an M dwarf, and such systems are commonly detected by gravitational microlensing. This adds another example of a possible pileup of sub-Jupiters in contrast to a lack of Jupiters () around M dwarfs, supporting the prediction by core accretion models that Jupiter-mass or more massive planets are unlikely to form around M dwarfs. [ABSTRACT FROM AUTHOR]

The X17.0 solar flare of 2005 September 7 released high-energy neutrons that were detected by the Solar Neutron Telescope (SNT) at Sierra Negra, Mexico. In three separate and independent studies of this solar neutron event, several of its unique characteristics were studied; in particular, a power-law energy spectra was estimated. In this paper, we present an alternative analysis, based on improved numerical simulations of the detector using GEANT4, and a different technique for processing the SNT data. The results indicate that the spectral index that best fits the neutron flux is around 3, in agreement with previous works. Based on the numerically calculated neutron energy deposition on the SNT, we confirm that the detected neutrons might have reached an energy of 1 GeV, which implies that 10 GeV protons were probably produced; these could not be observed at Earth, as their parent flare was an east limb event. [ABSTRACT FROM AUTHOR]