Calculation of the optical response of C60 and Na8 using time-dependent density functional theory and local orbitals

We report on a general method for the calculation of the frequency-dependent optical response of clusters based upon time-dependent density functional theory (TDDFT). The implementation is done using explicit propagation in the time domain and a self-consistent program that uses a linear combination of atomic orbitals (LCAO). Our actual calculations employ the SIESTA program, which is designed to be fast and accurate for large clusters. We use the adiabatic local density approximation to account for exchange and correlation effects. Results are presented for the imaginary part of the linear polarizability, Im [\alpha(w)], and the dipole strength function, S(w), of C60 and Na8, compared to previous calculations and to experiment. We also show how to calculate the integrated frequency-dependent second order non-linear polarizability for the case of a step function electric field, \gamma_{step}(w), and present results for C60.Comment: 11 pages with 6 postscript figures. Submitted for publicatio

Human resource management implications of new forms of organizing

Adopting a process view, we explore the personnel (HRM) implications of new forms of organizing (NFOs). We review the characteristics of NFOs and explain how they require a renewed HRM approach. We illustrate the HRM approach with preliminary results from a European comparative study, and comment on the challenges ahead.Human resource management;

Roles of transcriptional and translational control mechanisms in regulation of ribosomal protein synthesis in Escherichia coli

ABSTRACTBacterial ribosome biogenesis is tightly regulated to match nutritional conditions and to prevent formation of defective ribosomal particles. InEscherichia coli, most ribosomal protein (r-protein) synthesis is coordinated with rRNA synthesis by a translational feedback mechanism: when r-proteins exceed rRNAs, specific r-proteins bind to their own mRNAs and inhibit expression of the operon. It was recently discovered that the second messenger nucleotide guanosine tetra and pentaphosphate (ppGpp), which directly regulates rRNA promoters, is also capable of regulating many r-protein promoters. To examine the relative contributions of the translational and transcriptional control mechanisms to the regulation of r-protein synthesis, we devised a reporter system that enabled us to genetically separate thecis-acting sequences responsible for the two mechanisms and to quantify their relative contributions to regulation under the same conditions. We show that the synthesis of r-proteins from the S20 and S10 operons is regulated by ppGpp following shifts in nutritional conditions, but most of the effect of ppGpp required the 5′ region of the r-protein mRNA containing the target site for translational feedback regulation and not the promoter. These results suggest that most regulation of the S20 and S10 operons by ppGpp following nutritional shifts is indirect and occurs in response to changes in rRNA synthesis. In contrast, we found that the promoters for the S20 operon were regulated during outgrowth, likely in response to increasing nucleoside triphosphate (NTP) levels. Thus, r-protein synthesis is dynamic, with different mechanisms acting at different times.IMPORTANCEBacterial cells have evolved complex and seemingly redundant strategies to regulate many high-energy-consuming processes. InE. coli, synthesis of ribosomal components is tightly regulated with respect to nutritional conditions by mechanisms that act at both the transcription and translation steps. In this work, we conclude that NTP and ppGpp concentrations can regulate synthesis of ribosomal proteins, but most of the effect of ppGpp is indirect as a consequence of translational feedback in response to changes in rRNA levels. Our results illustrate how effects of seemingly redundant regulatory mechanisms can be separated in time and that even when multiple mechanisms act concurrently their contributions are not necessarily equivalent.</jats:p

Micellar dye shuttle between water and an ionic liquid

The reversible transfer of poly(2-ethyl-2-oxazoline)-block-poly(2-nonyl-2-oxazoline) nanocarriers comprising encapsulated dyes is demonstrated between water and an ionic liquid. This dye transfer concept is shown to be applicable for loading and delivery of dye molecules as well as to provide a protective environment for the encapsulated dye

Fast Sequence Component Analysis for Attack Detection in Synchrophasor Networks

Modern power systems have begun integrating synchrophasor technologies into part of daily operations. Given the amount of solutions offered and the maturity rate of application development it is not a matter of "if" but a matter of "when" in regards to these technologies becoming ubiquitous in control centers around the world. While the benefits are numerous, the functionality of operator-level applications can easily be nullified by injection of deceptive data signals disguised as genuine measurements. Such deceptive action is a common precursor to nefarious, often malicious activity. A correlation coefficient characterization and machine learning methodology are proposed to detect and identify injection of spoofed data signals. The proposed method utilizes statistical relationships intrinsic to power system parameters, which are quantified and presented. Several spoofing schemes have been developed to qualitatively and quantitatively demonstrate detection capabilities.Comment: 8 pages, 4 figures, submitted to IEEE Transaction

Evaluating K-16 Student Engagement In STEM-based Drone Racing

Increasing the number of students interested in pursuing careers in STEM, computer science, and technology is of widespread interest to education stakeholders. Yet, despite the tremendous amount of human and fiscal resources directed at increasing the STEM, CS, and CTE career pipelines, numbers are less than satisfying. In a purposeful effort to create a more rapid onramp to high tech careers, the project team implemented a series of competitive, quadcopter drone races for students. In these races, student drone pilots race through a timed obstacle course to determine which pilots navigate the challenge in the shortest amount of time. These events that served as a focal point for motivating students to learn about drone technology, encouraging students to develop precision flight skills, and providing educators both inside and outside of formal classrooms with a foundational structure to increase the quantity and quality of technology education. Assessment of students’ and educators’ perceptions suggest that the developed program provided a low barrier to entry and engagement pathway for students to become more deeply engaged in technology

Students And Faculty Perceptions Of Communications Channels: A Comparison Of Survey Results

Individual communication between faculty and students outside of the classroom is one of the cornerstones of education. This survey examines the students and faculty perceptions of three communications media for several communication tasks that occur between students and faculty. A random sample of 449 students (undergraduate and graduate, full-time and part-time) which represents 10% of the population at a small Texas state university were invited to participate in a survey that elicited their perceptions on the effectiveness of face-to-face (office hours), e-mail and telephone communication. Similarly a random sample of 49 professors, which represents 32 % of the faculty population, was used to test several hypotheses. In this survey, the relevant results supported by some nonparametric statistical analyses are that at each media channel the "bootstrapped" confidence intervals estimates for the percentages in communications-time preferences of students and faculty were very similar, or without a significant difference. In addition, students and faculty expressed simultaneously (criteria of convergence) the same preference-level about e-mail for convenience and efficiency. Office hours were preferred for confidentiality, confrontation and emotional support. Equal preference about e-mail and office hours was expressed by both groups of study for the criteria: accuracy and overall effectiveness