Xin Ma

The authors examined peer coaching in the context of the Mentored Implementation Program developed in the Appalachian Mathematics and Science Partnership. The experimental design contained 6 teachers receiving peer coaching with their 202 students and 5 teachers in the control group with their 105 students. Teachers considered peer coaching a positive experience, identifying scheduling and distance as roadblocks. Centering around (a) organization of learning, (b) management of classroom, and (c) mathematical content and pedagogy, collaborative interactions during the post-classroom-observation conferences were brief and showed (a) a lack of analysis, (b) a positive tone and support, (c) a proportional pattern of talk, and (d) a lack of depth in discussion. Peer coaching was not associated with any improvement in mathematics achievement of students.

<h2>Summary</h2> Cellular senescence plays critical roles in aging, regeneration, and disease; yet, the ability to discern its contributions across various cell types to these biological processes remains limited. In this study, we generated an <i>in vivo</i> genetic toolbox consisting of three <i>p16</i>^Ink4a-related intersectional genetic systems, enabling pulse-chase tracing (Sn-pTracer), Cre-based tracing and ablation (Sn-cTracer), and gene manipulation combined with tracing (Sn-gTracer) of defined <i>p16</i>^Ink4a+ cell types. Using liver injury and repair as an example, we found that macrophages and endothelial cells (ECs) represent distinct senescent cell populations with different fates and functions during liver fibrosis and repair. Notably, clearance of <i>p16</i>^Ink4a+ macrophages significantly mitigates hepatocellular damage, whereas eliminating <i>p16</i>^Ink4a+ ECs aggravates liver injury. Additionally, targeted reprogramming of <i>p16</i>^Ink4a+ ECs through <i>Kdr</i> overexpression markedly reduces liver fibrosis. This study illuminates the functional diversity of <i>p16</i>^Ink4a+ cells and offers insights for developing cell-type-specific senolytic therapies in the future.

Seven dimensions of school disciplinary climate were identified based on a representative sample of grade 8 students in the United States. Within schools students varied considerably in their perceptions and experiences about discipline. The variation was related mainly to students' socioeconomic status (SES), sex, and ethnicity. There was a significant contextual effect of school mean SES on disciplinary climate, larger titan the individual effect of SES. Schools with primary or intermediate grades tended to have more favorable disciplinary climates titan either junior or senior high schools. School location had small effects on disciplinary climate. The disciplinary measure with the strongest relationship to academic achievement pertained to classroom disruption.

Abstract This study examined gender differences in the rate of change in mathematics affect (attitude and anxiety toward mathematics and utility of mathematics) across middle and high school, using data from the Longitudinal Study of American Youth. Hierarchical linear models indicated no gender differences in the rate of decline in either attitude or utility, but females grew faster in anxiety than males. Schools were more responsible for variation in the male than female rate of change in mathematics affect. Student and school variables influenced the rate of change in mathematics affect in a quite different way between males and females.