A joint mid-course and terminal course cooperative guidance law for multi-missile salvo attack

Salvo attacking a surface target by multiple missiles is an effective tactic to enhance the lethality and penetrate the defense system. However, existing cooperative guidance laws in the mid-course or terminal course are not suitable for long- and medium-range missiles or stand-off attacking. Because the initial conditions of cooperative terminal guidance that are generally generated from the mid-course flight may not lead to a successful cooperative terminal guidance without proper mid-course flight adjustment. Meanwhile, cooperative guidance in the mid-course cannot solely guarantee the accuracy of a simultaneous arrival of multiple missiles. Therefore, a joint mid-course and terminal course cooperative guidance law is developed. By building a distinct leader-follower framework, this paper proposes an efficient coordinated Dubins path planning method to synchronize the arrival time of all engaged missiles in the mid-course flight. The planned flight can generate proper initial conditions for cooperative terminal guidance, and also benefit an earliest simultaneous arrival. In the terminal course, an existing cooperative proportional navigation guidance law guides all the engaged missiles to arrive at a target accurately and simultaneously. The integrated guidance law for an intuitive application is summarized. Simulations demonstrate that the proposed method can generate fast and accurate salvo attack.

Senescence Elicits Stemness: A Surprising Mechanism for Cancer Relapse

Cellular senescence is traditionally viewed as a permanent form of cell cycle arrest that restrains tumorigenesis. In a recent study in Nature, however, Milanovic et al. (2018) challenge this conventional view, showing that senescence can counterintuitively promote cancer stemness and tumor aggressiveness. This finding suggests that attacking senescence can be exploited in cancer therapy.

Robust closed-loop control of vegetable production in plant factory

Internal variations and external disturbances often adversely influence normal operation of plant factories and their production stability. In this research, a salad-cultivating plant factory (abbreviated as SPF) was considered as a dissipative system, its highly valid kinetic model was developed using system dynamics and experimental data. Optimal closed-loop control law of light intensity, temperature and aerating rate was then obtained based on the gradient of stored-energy (Lyapunov) function of the SPF derived from Hamilton-Jacobi-Isaacs equation. Both digital and real-time simulation results showed that the SPF closed-loop control system with optimal control law could continuously dissipate the stored energy, namely internal variation and external disturbances resulting from insect and microbial damage and other environmental fluctuations with different strengths to stabilize the SPF at an operating point and maintaining the good yield of salad with desired dynamic response characteristics to control actions. This research will lay a theoretical and method foundation for construction and operation of facility agricultural systems and closed artificial ecosystems.

Theoretical insights into the surface structure of In2O3(1 1 0) surface and its effect on methanol synthesis from CO2 hydrogenation

Ab inito study on the electronic structure and laser cooling of SiH

Thermodynamic costs of dynamic function in active soft matter

Spillover systems in a telecoupled Anthropocene: typology, methods, and governance for global sustainability

The world has become increasingly telecoupled through distant flows of information, energy, people, organisms, goods, and matter. Recent advances suggest that telecouplings such as trade and species invasion often generate spillover systems with profound effects. To untangle spillover complexity, we make the first attempt to develop a typology of spillover systems based on six criteria: flows from and to sending and receiving systems, distances from sending and receiving systems, types of spillover effects, sizes of spillover systems, roles of agents in spillover systems, and the origin of spillover systems. Furthermore, we highlight a portfolio of qualitative and quantitative methods for detecting the often-overlooked spillover systems. To effectively govern spillover systems for global sustainability, we propose an overall goal (minimize negative and maximize positive spillover effects) and three general principles (fairness, responsibility, and capability).

The InR/Akt/TORC1 Growth-Promoting Signaling Negatively Regulates JAK/STAT Activity and Migratory Cell Fate during Morphogenesis

Cell growth and cell differentiation are two distinct yet coupled developmental processes, but how they are coordinated is not well understood. During Drosophila oogenesis, we found that the growth-promoting InR/Akt/TOR pathway was involved in suppressing the fate determination of the migratory border cells. The InR/Akt/TOR pathway signals through TOR and Raptor, components of TORC1, to downregulate the JAK/STAT pathway, which is necessary and sufficient for border cell fate determination. TORC1 promotes the protein stability of SOCS36E, the conserved negative regulator of JAK/STAT signaling, through physical interaction, suggesting that TORC1 acts as a key regulator coordinating both cell growth and cell differentiation.

A Robust Transposon-Endogenizing Response from Germline Stem Cells

The heavy occupancy of transposons in the genome implies that existing organisms have survived from multiple, independent rounds of transposon invasions. However, how and which host cell types survive the initial wave of transposon invasion remain unclear. We show that the germline stem cells can initiate a robust adaptive response that rapidly endogenizes invading P element transposons by activating the DNA damage checkpoint and piRNA production. We find that temperature modulates the P element activity in germline stem cells, establishing a powerful tool to trigger transposon hyper-activation. Facing vigorous invasion, Drosophila first shut down oogenesis and induce selective apoptosis. Interestingly, a robust adaptive response occurs in ovarian stem cells through activation of the DNA damage checkpoint. Within 4 days, the hosts amplify P element-silencing piRNAs, repair DNA damage, subdue the transposon, and reinitiate oogenesis. We propose that this robust adaptive response can bestow upon organisms the ability to survive recurrent transposon invasions throughout evolution.

The effect of nitrogen implantation on resistive switching of tetrahedral amorphous carbon films

We report the effect of nitrogen implantation on the resistance switching of tetrahedral amorphous carbon (ta-C) films. Both unimplanted and implanted films show resistive switching, with a characteristic threshold voltage required to switch the films from the high-resistance to the low-resistance state. The switching voltages for the unimplanted films are between 7 and 10 V for ta-C films of thickness 15 to 40 nm. These are significantly reduced upon implantation by up to 60% when using an implantation dose ~3 × 1015 cm−2. We attribute this to increased sp2 bonding and clustering in the implanted films. This demonstrates the importance of sp2 clustering for resistive-switching in sp3-rich ta-C films.