Photochemical Reductive trans-Elimination from trans-Diacidotetracyanoplatinate(IV) Complexes

Abstract Upon CT excitation the complex ions trans-[Pt(CN)4N3X]2- and trans-[Pt(CN)4X2]2- (X = Cl and Br) undergo a reductive trans-elimination with formation of [Pt(CN)4]2- and two ligand radicals in the photoprimary step. The formation of a Pt(III) intermediate is not observed. Due to the stability of [Pt(CN)4]2-, recombination reactions regenerating the starting complex are efficient if the ligand radicals are not scavenged. For the azide complexes the high quantum yields for the production of [Pt(CN)4]2- are explained by the instability of azide radicals. For trans-[Pt(CN)4X2]2-, the recombination is efficient in aqueous solution, while in ethanol the halogen atoms are scavenged by hydrogen abstraction. The sequence of steps following CT excitation can be explained by a potential energy diagram.</jats:p

Slx5/Slx8-dependent ubiquitin hotspots on chromatin contribute to stress tolerance

Chromatin is a highly regulated environment, and protein association with chromatin is often controlled by post-translational modifications and the corresponding enzymatic machinery. Specifically, SUMO-targeted ubiquitin ligases (STUbLs) have emerged as key players in nuclear quality control, genome maintenance, and transcription. However, how STUbLs select specific substrates among myriads of SUMOylated proteins on chromatin remains unclear. Here, we reveal a remarkable co-localization of the budding yeast STUbL Slx5/Slx8 and ubiquitin at seven genomic loci that we term "ubiquitin hotspots". Ubiquitylation at these sites depends on Slx5/Slx8 and protein turnover on the Cdc48 segregase. We identify the transcription factor-like Ymr111c/Euc1 to associate with these sites and to be a critical determinant of ubiquitylation. Euc1 specifically targets Slx5/Slx8 to ubiquitin hotspots via bipartite binding of Slx5 that involves the Slx5 SUMO-interacting motifs and an additional, novel substrate recognition domain. Interestingly, the Euc1-ubiquitin hotspot pathway acts redundantly with chromatin modifiers of the H2A.Z and Rpd3L pathways in specific stress responses. Thus, our data suggest that STUbL-dependent ubiquitin hotspots shape chromatin during stress adaptation

Role of depreciation and the investment tax credit in tax policy and their influence on financial reporting during the 20th century

Since the inception of the modern income tax, the investment tax credit and depreciation have been some of the most modified provisions. This paper traces the history of major changes in depreciation and the investment tax credit along with the tax policy justifications given at the time the changes were made. In addition, the influence of tax depreciation on financial reporting is also discussed. An historical perspective of these two major provisions in tax should be helpful to policymakers and researchers attempting to assess the effectiveness of these policies

An Investigation of the Relationship Between Elementary Teachers\u27 Assessment of the Quality and Need for Professional Development, the Level of Teacher Self- Efficacy Evidenced by Faculty and Student Achievement Outcomes Measured School-Wide

Despite the vast existing body of research on professional development and student achievement, little is known about how teachers\u27 perceptions of professional development relate to other aspects of their classroom effectiveness. This research attempted to link elementary teachers\u27 assessment of the quality of professional development, need for professional development and collective teacher efficacy with student achievement at their school. This research also examined the possible influence that teachers\u27 number of years of experience, and their staying or leaving the teaching profession, have on their perceptions in relationship to student achievement. This quantitative study used secondary data analysis from the Measures of Effective Teaching (MET) Working Condition Survey and state achievements tests (2009-2010). The correlation with individual and school-level outcomes showed quality of professional development and collective teacher efficacy as the strongest relationship, though teachers\u27 perceptions at the school level were linked with student achievement. When teachers were placed in subgroups based on years of teaching and professional development impact on student learning, correlations between quality of professional development scale means, sum of professional development needs and collective faculty efficacy means were statically significant in each subgroup. However, using the Fisher r to z transformation, tests of the difference between two independent variables showed no strength in their relationships. Finally, elementary teachers who remained at their schools outperformed teachers who chose to leave the profession. Future research should focus on which specific types of professional development are essential to classroom teachers\u27 needs