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We report a photometric and asteroseismic analysis of KIC 3868420, a newly identified high-amplitude δ Scuti–γ Doradus hybrid star located in the Hertzsprung gap—a short-lived and rarely observed post-main-sequence phase. Using 4 yr of Kepler long-cadence photometry, we detect 36 significant frequencies, including 11 independent modes spanning both low- and high-frequency regimes. Grid-based modeling with MESA and GYRE, including rotation, shows that five independent frequencies match a combination of radial p-modes and nonradial g-modes, supporting its hybrid nature. The best-fit models yield an evolved post-main-sequence star (M ∼ 2.26–2.30M⊙, R ∼ 4.41–4.43R⊙, and τ ∼ 5.4 × 108 yr), although degeneracies from rotation and unknown inclination preclude a unique solution. KIC 3868420 thus represents a rare example of a high-amplitude hybrid pulsator in the Hertzsprung gap, demonstrating that high-amplitude pulsation can coexist with mixed p-/g-mode behavior in a rapidly evolving star. This finding highlights the value of space-based photometry for identifying such rare objects.

While transformation of the major monocot crops is currently possible, the process typically remains confined to one or two genotypes per species, often with poor agronomics, and efficiencies that place these methods beyond the reach of most academic laboratories. Here, we report a transformation approach involving overexpression of the maize (Zea mays) Baby boom (Bbm) and maize Wuschel2 (Wus2) genes, which produced high transformation frequencies in numerous previously nontransformable maize inbred lines. For example, the Pioneer inbred PHH5G is recalcitrant to biolistic and Agrobacterium tumefaciens transformation. However, when Bbm and Wus2 were expressed, transgenic calli were recovered from over 40% of the starting explants, with most producing healthy, fertile plants. Another limitation for many monocots is the intensive labor and greenhouse space required to supply immature embryos for transformation. This problem could be alleviated using alternative target tissues that could be supplied consistently with automated preparation. As a major step toward this objective, we transformed Bbm and Wus2 directly into either embryo slices from mature seed or leaf segments from seedlings in a variety of Pioneer inbred lines, routinely recovering healthy, fertile T0 plants. Finally, we demonstrated that the maize Bbm and Wus2 genes stimulate transformation in sorghum (Sorghum bicolor) immature embryos, sugarcane (Saccharum officinarum) callus, and indica rice (Oryza sativa ssp indica) callus.

Several Algol-type binaries were detected to be experiencing rapid orbital decay, which is in contradiction with the conservative mass transfer model. In this work, we investigate whether anomalous magnetic braking (MB) of intermediate-mass Ap/Bp stars, characterized by surface magnetic fields of ∼102–104 G, could drive orbital decay through magnetic wind–field coupling. Using the stellar evolution code MESA, we simulate the evolution of several main-sequence binaries containing Ap/Bp stars, with typical initial parameters of Algol binaries. Our models indicate that the anomalous MB mechanism could induce orbital decay in long timescales (hundreds of Myr to several Gyr), reproducing several basic Algol parameters such as the effective temperatures and luminosities of donor stars. However, the predicted orbital period decay rates are much lower than those observed in several Algol systems. We analyze the limitations of the anomalous MB model and discuss alternative mechanisms that could account for the long- or short-term orbital period variations observed in Algol systems, including a surrounding circumbinary disk, stellar expansion, the Applegate mechanism, and the light-travel-time effect. Long-term observations are still required to distinguish between these mechanisms in the future.

Summary Sorghum is the fifth most widely planted cereal crop in the world and is commonly cultivated in arid and semi‐arid regions such as Africa. Despite its importance as a food source, sorghum genetic improvement through transgenic approaches has been limited because of an inefficient transformation system. Here, we report a ternary vector (also known as cohabitating vector) system using a recently described pVIR accessory plasmid that facilitates efficient Agrobacterium‐mediated transformation of sorghum. We report regeneration frequencies ranging from 6% to 29% in Tx430 using different selectable markers and single copy, backbone free ‘quality events’ ranging from 45% to 66% of the total events produced. Furthermore, we successfully applied this ternary system to develop transformation protocols for popular but recalcitrant African varieties including Macia, Malisor 84‐7 and Tegemeo. In addition, we report the use of this technology to develop the first stable CRISPR/Cas9‐mediated gene knockouts in Tx430.

We investigated the pulsating behavior of TIC 400562821 using high-precision observations from TESS. Fourier analysis of time-series data revealed three independent frequencies. The period ratios of F to F1 (0.774) and F to F2 (0.625), along with an amplitude change of approximately 0.1 mag, indicate that TIC 400562821 is a triple-mode High-Amplitude δ Scuti (HADS) star. Using the Best Parent Method and the Γ O functions, we identified that the harmonics and sum combination frequencies of F and F1 are caused by the nonlinear response of the stellar medium to pulsation. We also analyzed the amplitude variations of F, F1, and F2. Observational data over 76 days show stable amplitudes for these modes. However, Radial Stellar Pulsations modeling suggests that, over 10,000 cycles, the amplitude of F remains constant, while F1 gradually decreases and F2 approaches zero. This implies that TIC 400562821 may eventually evolve into a single-mode HADS star. Furthermore, asteroseismic modeling was performed, and several effects, such as the mixing-length parameter α MLT and nonadiabatic, were examined on this star. In view of the results by Daszyńska-Daszkiewicz et al. (i.e., α MLT < ∼1 for δ Scuti stars), TIC 400562821 is suggested to be more likely in the post-main-sequence stage, with mass M = 1.34–1.38 M ⊙ and metallicity Z = 0.007–0.008, but still warrants further study to ascertain its nature.

In this paper, we present an analysis of the pulsating behavior of Kepler target KIC 9845907. Using the data from Kepler, we detected 85 significant frequencies, including the first overtone f 1 = 17.597 day−1 as the dominant frequency, the non-radial independent frequency f 3 = 31.428 day−1 (ℓ = 1), as well as two modulation terms f m1 = 0.065 day−1 and f m2 = 1.693 day−1. We found fourteen pairs of triplet structures with f m1 or f m2, four pairs of which can further form quintuplet structures. We note these are the most intriguing features discovered in this study and they were recognized for the first time in δ Scuti stars. We discussed several possible explanations, i.e., beating, the Blazhko effect, combination mode hypothesis, nonlinear mode coupling, large separation, and stellar rotational splitting for these equidistant structures. Our asteroseismic models indicate this modulation with f m1 might be related to the rotational splitting. The study of more δ Scuti stars with triplet and/or quintuplet structures using high-precision space photometry would be helpful to further explore its origin.

In this paper, we present a detailed analysis of the light variation of KIC 5623923 using high-precision time-series data from the Kepler mission. The analysis reveals this target is an eclipsing binary system with δ Scuti-type pulsations from the primary component, rather than from the secondary as previously reported. The frequency analysis of three short-cadence data reveals 41 significant frequencies, including the orbital frequency (forb = 0.827198 day−1) due to orbital motion from the binary system and the pulsational frequencies. Most of the pulsational signal lies in the frequency range of 20–32 day−1, with amplitude between 0.3 and 8.8 mmag, in which seven peaks are identified as “independent” modes. The strongest one (f3 = 28.499399 day−1) likely corresponds to a high-order radial mode. In other peaks (f7, f10, and f18), several pairs of multiplet structures centered on them are found. The fitting of spectral energy distribution using the collected photometry measurement of multiple bands reveals the effective temperatures of the primary and secondary components as 8348−225+230 K and 4753−229+237 K, respectively, which place the primary star in the classical pulsating instability zone. The characteristic light-curve morphology and short orbital period are consistent with a tidally locked system. Based on the characteristics of amplitude spectra of pulsating stars in close binaries, the analysis of the multiplet structures reveals that three independent frequencies (i.e., f7, f10, and f18) correspond to nonradial modes with l = 2, while the associated sidelobes are produced by the orbital motion. We highlight the potential of this method in future studies of pulsating binary stars.

In this paper, we analyze the light variation of KIC 8840638 using high-precision time-series data from the Kepler mission. The analysis reveals that this target is a new detached eclipsing binary system with a δ Scuti component, rather than a single δ Scuti star as previously known. The frequency analysis of short-cadence data reveals 95 significant frequencies, most of which lie in a frequency range of 23−32 day−1. Among them, seven independent frequencies are detected in the typical frequency range of δ Scuti stars, and they are identified as pressure modes. In addition, a possible large separation value of Δν = 36.5 ± 0.1 μHz is also detected with the Fourier transform (FT) and autocorrelation function (AC) analysis. The orbital frequency f orb (= 0.320008 day−1) and its harmonics are also detected directly in the frequency spectrum. The binary modelings derived from PHOEBE indicate that this binary system is in detached configurations with a mass ratio of q=0.33−0.04+0.06 , an inclination angle of 40.19−2.84+3.96 ​​​​​°. The derived parameters and binary evolutionary model suggest that the primary star is an object on the verge of leaving the main sequence with a temperature of ∼7600 K, while the secondary appears to be a cool component entering the giant branch with a temperature ∼3100 K lower than the primary. Moreover, this system may have undergone a mass ratio reversal, where the more massive star is the gainer component and the less massive one is the donor star.

Agrobacterium-mediated sorghum transformation frequency has been enhanced significantly via medium optimization using immature embryos from sorghum variety TX430 as the target tissue. The new transformation protocol includes the addition of elevated copper sulfate and 6-benzylaminopurine in the resting and selection media. Using Agrobacterium strain LBA4404, the transformation frequency reached over 10% using either of two different selection marker genes, moPAT or PMI, and any of three different vectors in large-scale transformation experiments. With Agrobacterium strain AGL1, the transformation frequencies were as high as 33%. Using quantitative PCR analyses of 1,182 T₀ transgenic plants representing 675 independent transgenic events, data was collected for T-DNA copy number, intact or truncated T-DNA integration, and vector backbone integration into the sorghum genome. A comparison of the transformation frequencies and molecular data characterizing T-DNA integration patterns in the transgenic plants derived from LBA4404 versus AGL1 transformation revealed that twice as many transgenic high-quality events were generated when AGL1 was used compared to LBA4404. This is the first report providing molecular data for T-DNA integration patterns in a large number of independent transgenic plants in sorghum.

We have modeled the luminosity-displacement correlation of high-mass X-ray binaries (HMXBs) with an evolutionary population synthesis (EPS) code. Detailed properties including offsets of simulated HMXBs are presented under both common envelope prescriptions usually adopted (i.e., the α CE formalism and the γ algorithm), and several theoretical models describing the natal kicks. We suggest that the distinct observational properties may be used as potential evidence to discriminate between models.