Superintendent Transitioning: When is the Right Time to Make a Move?

Leadership preparation programs prepare superintendents every year to enter the profession. One aspect that needs to be incorporated into this learning is the understanding of when it\u27s the right time to leave as many superintendents leave their current position every year for one reason or another. These reasons can range from being fired to career advancements to leaving the profession. Leaving at the right time is crucial for your career and the district. Lashway (2002) posited that almost a quarter of the superintendents serve less than three years, there are many superintendents leaving positions

Chemotherapy-induced senescent cancer cells engulf other cells to enhance their survival.

In chemotherapy-treated breast cancer, wild-type p53 preferentially induces senescence over apoptosis, resulting in a persisting cell population constituting residual disease that drives relapse and poor patient survival via the senescence-associated secretory phenotype. Understanding the properties of tumor cells that allow survival after chemotherapy treatment is paramount. Using time-lapse and confocal microscopy to observe interactions of cells in treated tumors, we show here that chemotherapy-induced senescent cells frequently engulf both neighboring senescent or nonsenescent tumor cells at a remarkable frequency. Engulfed cells are processed through the lysosome and broken down, and cells that have engulfed others obtain a survival advantage. Gene expression analysis showed a marked up-regulation of conserved macrophage-like program of engulfment in chemotherapy-induced senescent cell lines and tumors. Our data suggest compelling explanations for how senescent cells persist in dormancy, how they manage the metabolically expensive process of cytokine production that drives relapse in those tumors that respond the worst, and a function for their expanded lysosomal compartment

Revealing Electronic Signatures of Lattice Oxygen Redox in Lithium Ruthenates and Implications for High-Energy Li-Ion Battery Material Designs

Anion redox in lithium transition-metal oxides such as Li2RuO3 and Li2MnO3 has catalyzed intensive research efforts to find transition-metal oxides with anion redox that may boost the energy density of lithium-ion batteries. The physical origin of the observed anion redox remains debatable, and more direct experimental evidence is needed. In this work, we have shown electronic signatures of oxygen-oxygen coupling, direct evidence central to lattice oxygen redox (O2-/(O2)n-), in charged Li2-xRuO3 after Ru oxidation (Ru4+/Ru5+) upon first electron removal with lithium deintercalation. Experimental Ru L3-edge high-energy-resolution fluorescence-detected X-ray absorption spectra (HERFD-XAS), supported by ab initio simulations, revealed that the increased intensity in the high-energy shoulder upon lithium deintercalation resulted from increased O-O coupling, inducing (O-O) σ*-like states with πoverlap with Ru d-manifolds, in agreement with O K-edge XAS spectra. Experimental and simulated O K-edge X-ray emission spectra further supported this observation with the broadening of the oxygen nonbonding feature upon charging, also originated from (O-O) σ∗ states. This lattice oxygen redox of Li2-xRuO3 was accompanied by a small amount of O2 evolution in the first charge from differential electrochemistry mass spectrometry but diminished in the subsequent cycles, in agreement with the more reduced states of Ru in later cycles from Ru L3-edge HERFD-XAS. These observations indicated that Ru redox contributed more to discharge capacities after the first cycle. This study has pinpointed the key spectral fingerprints related to lattice oxygen redox from a molecular level and constructed a transferrable framework to rationally interpret the spectroscopic features by combining advanced experiments and theoretical calculations to design materials for Li-ion batteries and electrocatalysis applications