Nonlinear waves in heterogeneous elastic rods via homogenization

We consider the propagation of a planar loop on a heterogeneous elastic rod with a periodic microstructure consisting of two alternating homogeneous regions with different material properties. The analysis is carried out using a second-order homogenization theory based on a multiple scale asymptotic expansion

Development and Implementation of an Administrative Internship Program

This article describes the development and implementation of a pilot program to prepare teachers seeking New York State certification as School District Administrators, by assigning them as administrative interns to a school district. The district superintendent of a large urban school district and the college program director partnered to design a pilot experiential course to take the place of an existing internship course for eight candidates. The dual purpose was to provide an authentic learning experience for the candidates, and to provide actionable information for the superintendent for improvement of the district instructional program. The candidates reviewed the New York State District Report Card to identify areas of academic concern, conducted research, and interviewed district personnel to make suggestions and recommendations for academic improvement. Findings and recommendations were presented to the superintendent and his administrative staff to inform district improvement efforts, and for improvement of the existing course. Recommendations are included

Structural and chemical requirements for histidine phosphorylation by the chemotaxis kinase CheA

The CheA histidine kinase initiates the signal transduction pathway of bacterial chemotaxis by autophosphorylating a conserved histidine on its phosphotransferase domain (P1). Site-directed mutations of neighboring conserved P1 residues (Glu-67, Lys-48, and His-64) show that a hydrogen-bonding network controls the reactivity of the phospho-accepting His (His-45) in Thermotoga maritima CheA. In particular, the conservative mutation E67Q dramatically reduces phospho-transfer to P1 without significantly affecting the affinity of P1 for the CheA ATP-binding domain. High resolution crystallographic studies revealed that although all mutants disrupt the hydrogen-bonding network to varying degrees, none affect the conformation of His-45. N-15-NMR chemical shift studies instead showed that Glu-67 functions to stabilize the unfavored (NH)-H-delta 1 tautomer of His-45, thereby rendering the N-epsilon 2 imidazole unprotonated and well positioned for accepting the ATP phosphoryl group

The Hepatitis C Virus NS5A Stimulates NS5B During In Vitro RNA Synthesis in a Template Specific Manner

The hepatitis C virus (HCV) NS5B protein contains the RNA dependent RNA polymerase (RdRp) activity that catalyzes the synthesis of the viral genome with other host and viral factors. NS5A is an HCV-encoded protein previously shown to localize to the replisome and be necessary for viral replication. However, its role in replication has not been defined. Using an in vitro biochemical assay, we detected a stimulatory effect of NS5A on the NS5B replication reaction with minimal natural templates. NS5A stimulates replication by NS5B on two templates derived from the 3’ end of the RNA genome (4 fold ± 1.3 fold). A pre-incubation step with the two proteins prior to the replication reaction and substoichiometric levels of NS5A are required for detecting stimulation. With a template derived from the 3’end complementary to the RNA genome (the negative strand) no stimulation was observed. Furthermore, with a synthetic template that allows studying different phases of replication, NS5A stimulates NS5B during elongation. These findings suggest that NS5A stimulates NS5B during synthesis of the complementary (i.e., negative) strand of the RNA genome

Observation of strong-coupling effects in a diluted magnetic semiconductor (Ga,Fe)N

A direct observation of the giant Zeeman splitting of the free excitons in (Ga,Fe)N is reported. The magnetooptical and magnetization data imply the ferromagnetic sign and a reduced magnitude of the effective p-d exchange energy governing the interaction between Fe^{3+} ions and holes in GaN, N_0 beta^(app) = +0.5 +/- 0.2 eV. This finding corroborates the recent suggestion that the strong p-d hybridization specific to nitrides and oxides leads to significant renormalization of the valence band exchange splitting.Comment: 4 pages, 2 figure

Hydraulic projects prioritization in the steel industry : an analytic hierarchy process approach

Ferreira, Ana Cristina, e outros (2023) - International conference on technology management and operations. - Lisboa : Universidade Lusíada Editora. - ISBN 978-898-640-273-0.The increased use of high-precision operational functions in the steel industry makes hydraulic systems one of the items that require more attention. The prioritization in the modernization of hydraulic projects is one of the critical issues in maintenance management, which involves multiple criteria that should be considered. To solve such problems, multi-criteria decision methods are considered an advantage. To define the model’s multi-criteria structure, the Benefits, Opportunities, Costs, and Risks, based on Analytic Hierarchy Process, were applied, considering the possibility of group decision-making. The aim of this research is to propose an evaluation framework for the prioritization of hydraulic projects in the steel industry. With this study, managers and executives can define adequate policies and methods that allow them to guide their decisions in a clear way. Three alternatives were associated with criteria and sub-criteria, available in a hierarchical decision tree, based on the literature and feedback received from the industry experts. The proposed model was applied in a steel plant located in the Brazilian State of Rio de Janeiro. As a general result, this research contributes to the development of a useful decision support tool, enabling a clear view of the most significant factor disposed on a hierarchical tree, and the priority classification of hydraulic system projects in the context of the steel industry