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Prime editors are reverse transcriptase (RT)-based genome-editing tools that utilize double-strand break (DSB)-free mechanisms to decrease off-target editing in genomes and enhance the efficiency of targeted insertions. The multiple prime editors that have been developed within a short span of time are a testament to the potential of this technique for targeted insertions. This is mainly because of the possibility of generation of all types of mutations including deletions, insertions, transitions, and transversions. Prime editing reverses several bottlenecks of gene editing technologies that limit the biotechnological applicability to produce designer crops. This review evaluates the status and evolution of the prime editing technique in terms of the types of editors available up to prime editor 5 and twin prime editors, and considers the developments in plants in a systematic manner. The various factors affecting prime editing efficiency in plants are discussed in detail, including the effects of temperature, the prime editing guide (peg)RNA, and RT template amongst others. We discuss the current obstructions, key challenges, and available resolutions associated with the technique, and consider future directions and further improvements that are feasible to elevate the efficiency in plants.

 

Graduate students’ mental health and well-being is a prominent concern across various disciplines. However, early predictors of mental health and well-being in graduate education, specifically doctoral education, have rarely been studied. The present study evaluated both the underlying latent classification of individuals’ mental well-being and predictors of those classifications. Results estimated two latent classes of students’ mental health and well-being: one class with generally high levels of mental well-being and one with lower levels of mental well-being. Regression analyses showed that mentoring in the second year of doctoral study, certainty of choice in the third year, and both academic development and sense of belonging in the fourth year were positive predictors of membership in the higher mental well-being class. In contrast to some prior studies, demographic variables were not related to the identified well-being classifications. Regression analyses further showed that mental well-being was negatively related to participants’ number of publications and research self-efficacy, indicating a problematic relationship between scholarly productivity and confidence and well-being. These findings may be used to identify and provide targeted support for students who are at-risk for having or developing lower levels of mental well-being in their graduate programs. 

The Earth's inner core started forming when molten iron cooled below the melting point. However, the nucleation mechanism, which is a necessary step of crystallization, has not been well understood. Recent studies have found that it requires an unrealistic degree of undercooling to nucleate the stable, hexagonal, close-packed (hcp) phase of iron that is unlikely to be reached under core conditions and age. This contradiction is referred to as the inner core nucleation paradox. Using a persistent embryo method and molecular dynamics simulations, we demonstrate that the metastable, body-centered, cubic (bcc) phase of iron has a much higher nucleation rate than does the hcp phase under inner core conditions. Thus, the bcc nucleation is likely to be the first step of inner core formation, instead of direct nucleation of the hcp phase. This mechanism reduces the required undercooling of iron nucleation, which provides a key factor in solving the inner core nucleation paradox. The two-step nucleation scenario of the inner core also opens an avenue for understanding the structure and anisotropy of the present inner core.