The isotopes 60 Fe and 26 Al originate from massive stars and their supernovae, reflecting ongoing nucleosynthesis in the Galaxy. We studied the gamma-ray emission from these isotopes at characteristic energies 1173, 1332, and 1809 keV with over 15 years of SPI data, finding a line flux in 60 Fe combined lines of (0.31 ± 0.06) × 10 −3 ph cm −2 s −1 and the 26 Al line flux of (16.8 ± 0.7) × 10 −4 ph cm −2 s −1 above the background and continuum emission for the whole sky. Based on the exponentialdisk grid maps, we characterise the emission extent of 26 Al to find scale parameters R 0 = 7.0 +1.5 −1.0 kpc and z 0 = 0.8 +0.3 −0.2 kpc, however the 60 Fe lines are too weak to spatially constrain the emission. Based on a point source model test across the Galactic plane, the 60 Fe emission would not be consistent with a single strong point source in the Galactic center or somewhere else, providing a hint for a diffuse nature. We carried out comparisons of emission morphology maps using different candidate-source tracers for both 26 Al and 60 Fe emissions, and suggests that the 60 Fe emission is more likely to be concentrated towards the Galactic plane. We determine the 60 Fe / 26 Al γ-ray flux ratio at (18.4 ± 4.2) % , when using a parameterized spatial morphology model. Across the range of plausible morphologies, it appears possible that 26 Al and 60 Fe are distributed differently in the Galaxy. Using the best fitting maps for each of the elements, we constrain flux ratios in the range 0.2-0.4. We discuss its implications for massive star models and their nucleosynthesis.

As sessile organisms, plants have evolved a wide range of defence pathways to cope with environmental stress such as heat shock. However, the molecular mechanism of these defence pathways remains unclear in rice. In this study, we found that OsHSFA2d, a heat shock transcriptional factor, encodes two main splice variant proteins, OsHSFA2dI and OsHSFA2dII in rice. Under normal conditions, OsHSFA2dII is the dominant but transcriptionally inactive spliced form. However, when the plant suffers heat stress, OsHSFA2d is alternatively spliced into a transcriptionally active form, OsHSFA2dI, which participates in the heat stress response (HSR). Further study found that this alternative splicing was induced by heat shock rather than photoperiod. We found that OsHSFA2dI is localised to the nucleus, whereas OsHSFA2dII is localised to the nucleus and cytoplasm. Moreover, expression of the unfolded protein response (UNFOLDED PROTEIN RESPONSE) sensors, OsIRE1, OsbZIP39/OsbZIP60 and the UNFOLDED PROTEIN RESPONSE marker OsBiP1, was up-regulated. Interestingly, OsbZIP50 was also alternatively spliced under heat stress, indicating that UNFOLDED PROTEIN RESPONSE signalling pathways were activated by heat stress to re-establish cellular protein homeostasis. We further demonstrated that OsHSFA2dI participated in the unfolded protein response by regulating expression of OsBiP1.

A sub-array of the Large High Altitude Air Shower Observatory (LHAASO), KM2A is mainly designed to observe a large fraction of the northern sky to hunt for γ-ray sources at energies above 10 TeV. Even though the detector construction is still underway, half of the KM2A array has been operating stably since the end of 2019. In this paper, we present the KM2A data analysis pipeline and the first observation of the Crab Nebula, a standard candle in very high energy γ-ray astronomy. We detect γ-ray signals from the Crab Nebula in both energy ranges of 10 100 TeV and 100 TeV with high significance, by analyzing the KM2A data of 136 live days between December 2019 and May 2020. With the observations, we test the detector performance, including angular resolution, pointing accuracy and cosmic-ray background rejection power. The energy spectrum of the Crab Nebula in the energy range 10-250 TeV fits well with a single power-law function dN/dE = (1.13 0.05 0.08 ) 10 (E/20 TeV) cm s TeV . It is consistent with previous measurements by other experiments. This opens a new window of γ-ray astronomy above 0.1 PeV through which new ultrahigh-energy γ-ray phenomena, such as cosmic PeVatrons, might be discovered.

In this work, we reinvestigate the electron fraction Ye and electron Fermi energy EF(e) of neutron stars, based on our previous work, in which we first deduce a special solution to EF(e), and then obtain several useful analytical formulae for Ye and matter density ρ within classical models and the relativistic mean‐field (RMF) theory using numerical fitting. The advantages of this formalism include the following: (a) Linear functions are substituted for the nonlinear exponential functions used in the previous work. This method may be simpler and closer to realistic equation of state (EoS) of a neutron star (NS) because there are linear or quasi‐linear relationships between number fractions of leptons and matter density, which can be seen by solving NS EoS. (b) We introduce a dimensionless variable ϱ (ϱ = ρ/ρ0, ρ0 is the standard saturated nuclear density), which greatly reduces the scope of the fitting coefficients. (c) We present numerical errors including absolute and relative deviations between the data and fit. By numerical simulations, we obtain several analytical formulae for Ye and ρ for both APR98 and RMF models. Combining these analytical formulae with the special solution, we can calculate the value of EF(e) for any given matter density. Since Ye and EF(e) are important in assessing the cooling rate of an NS and the possibility of kaon/pion condensation in the NS's interior, this formalism could be useful in the future studies on the thermal evolution of an NS.

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