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Induction of cell fates by growth factors impacts many facets of developmental biology and disease. LIN-3/EGF induces the equipotent vulval precursor cells (VPCs) in Caenorhabditis elegans to assume the 3°-3°-2°-1°-2°-3° pattern of cell fates. 1° and 2° cells become specialized epithelia and undergo stereotyped series of cell divisions to form the vulva. Conversely, 3° cells are relatively quiescent and nonspecialized; they divide once and fuse with the surrounding epithelium. 3° cells have thus been characterized as passive, uninduced, or ground state. Based on our previous studies, we hypothesized that a 3°-promoting program would confer resistance to cell fate-transformation by inappropriately activated 1° and 2° fate-promoting LET-60/Ras and LIN-12/Notch, respectively. Deficient MIG-15/CNH-MAP4 Kinase meets the expectations of genetic interactions for a 3°-promoting protein. Moreover, endogenous MIG-15 is required for expression of a fluorescent biomarker of 3° cell fate, is expressed in VPCs, and functions cell autonomously in VPCs. The Ras family small GTPase RAP-2, orthologs of which activate orthologs of MIG-15 in other systems, emulates these functions of MIG-15. However, gain of RAP-2 function has no effect on patterning, suggesting its activity is constitutive in VPCs. The 3° biomarker is expressed independently of the AC, raising questions about the cellular origin of 3°-promoting activity. Activated LET-60/Ras and LIN-12/Notch repress expression of the 3° biomarker, suggesting that the 3°-promoting program is both antagonized by as well as antagonizes 1°-and 2°-promoting programs. This study provides insight into developmental properties of cells historically considered to be nonresponding to growth factor signals. [ABSTRACT FROM AUTHOR]

The present study explores the relationship between the concepts of foreign language (L2) learners' resilience and their behavioral, emotional, cognitive, and agentic engagement. It also aims to understand the role of L2 resilience in students' overall engagement. The study employs a quantitative approach and utilizes online questionnaires by which it collected data from 123 English as a foreign language (EFL) university students. Data analysis procedures involved descriptive statistics, correlation analysis to identify the levels of L2 resilience and engagement among the EFL participants as well as the associations between these constructs; and a multiple regression analysis to unveil the explanatory power of learner resilience in language engagement. The findings revealed moderate levels of L2 resilience and overall engagement as well as significant correlations between learners' resilience and their overall engagement and its four dimensions. The linear multiple regression analysis showed that EFL learners' resilience has explained around a third (30%) of the total variance in their overall engagement. These findings provide insights into the importance of EFL learners' resilience in accounting for their engagement. Such findings highlight the significance of promoting learners' resilience for the purpose of enhancing their L2 engagement and thereby leading a successful language learning journey. [ABSTRACT FROM AUTHOR]