Unconventional magnetism in multivalent charge-ordered YbPtGe2_2 probed by 195^{195}Pt- and 171^{171}Yb-NMR

Detailed $^{195}$Pt- and $^{171}$Yb nuclear magnetic resonance (NMR) studies on the heterogeneous mixed valence system YbPtGe$_2$ are reported. The temperature dependence of the $^{195}$Pt-NMR shift $^{195}K(T)$ indicates the opening of an unusual magnetic gap below 200\,K. $^{195}K(T)$ was analyzed by a thermal activation model which yields an isotropic gap $\Delta/k_B \approx 200$\,K. In contrast, the spin-lattice relaxation rate $^{195}$($1/T_1$) does not provide evidence for the gap. Therefore, an intermediate-valence picture is proposed while a Kondo-insulator scenario can be excluded. Moreover, $^{195}$($1/T_1$) follows a simple metallic behavior, similar to the reference compound YPtGe$_2$. A well resolved NMR line with small shift is assigned to divalent $^{171}$Yb. This finding supports the proposed model with two sub-sets of Yb species (di- and trivalent) located on the Yb2 and Yb1 site of the YbPtGe$_2$ lattice.Comment: Submitted in Physical Review B (Rapid Communication

How career variety promotes the adaptability of managers: a theoretical model

This paper presents a theoretical model showing how managerial adaptability develops from career variety over the span of the person’s career. By building on the literature of career theory, adult learning and development, and career adjustment, we oVer a new conceptualization of managerial adaptability by identifying its behavioral, cognitive, and socio-emotional dimensions, discuss how these competencies can develop from the variety of managers’ cumulative career experiences, and propose several individual and career-related factors that moderates the relationship between managerial career variety and adaptability

Requirements for a Research-oriented IC Design System

Computer-aided design techniques for integrated circuits grown in an incremental way, responding to various perceived needs, so that today there are a number of useful programs for logic generation, simulation at various levels, test preparation, artwork generation and analysis (including design rule checking), and interactive graphical editing. While the design of many circuits has benefitted from these programs, when industry wants to produce a high-volume part, the design and layout are done manually, followed by digitizing and perhaps some graphic editing before it is converted to pattern generation format, leading to the often heard statement that computer-aided design of integrated circuits doesn't work. If progress is to be made, it seems clear that the entire design process has to be thought through in basic terms, and much more attention must be paid to the way in which computational techniques can complement the designer's abilities. Currently, it is appropriate to try to characterize the design process in abstract terms, so that implementation and technological biases don't cloud the view of a desired system. In this paper, we briefly describe the conversion of algorithms to masks at a very general level, and then describe several projects at MIT which aim to provide contributions to an integrated design system. It is emphasized that no complete system design exists now at MIT, and that we believe that general design considerations must constantly be tested by building (and rebuilding) the various subcomponents, the structure of which is guided by our view of the overall design process

Periplakin, a novel component of cornified envelopes and desmosomes that belongs to the plakin family and forms complexes with envoplakin

The cornified envelope is a layer of transglutaminase cross-linked protein that is assembled under the plasma membrane of keratinocytes in the outermost layers of the epidermis. We have determined the cDNA sequence of one of the proteins that becomes incorporated into the cornified envelope of cultured epidermal keratinocytes, a protein with an apparent molecular mass of 195 kD that is encoded by a mRNA with an estimated size of 6.3 kb. The protein is expressed in keratinizing and nonkeratinizing stratified squamous epithelia and in a number of other epithelia. Expression of the protein is upregulated during the terminal differentiation of epidermal keratinocytes in vivo and in culture. Immunogold electron microscopy was used to demonstrate an association of the 195-kD protein with the desmosomal plaque and with keratin filaments in the differentiated layers of the epidermis. Sequence analysis showed that the 195-kD protein is a member of the plakin family of proteins, to which envoplakin, desmoplakin, bullous pemphigoid antigen 1, and plectin belong. Envoplakin and the 195-kD protein coimmunoprecipitate. Analysis of their rod domain sequences suggests that the formation of both homodimers and heterodimers would be energetically favorable. Confocal immunofluorescent microscopy of cultured epidermal keratinocytes revealed that envoplakin and the 195-kD protein form a network radiating from desmosomes, and we speculate that the two proteins may provide a scaffolding onto which the cornified envelope is assembled. We propose to name the 195-kD protein periplakin

Computing Shock Waves in Cloud Cavitation

This paper presents a numerical investigation of some of the phenomena involved in the nonlinear dynamics of a homogeneous bubbly mixture bounded by an oscillatory wall. This problem represents an idealization of the flow in a typical vibratory cavitation damage device. Results are presented showing that wave steepening and ultimately shock wave formation occur as the magnitude of the excitation increases. The propagation characteristics of the waves through the bubbly medium have also been studied. Strong pressure peaks of short duration, corresponding to the coherent collapse of the bubble clusters, are computed and accurately resolved, both in space and time. As the amplitude of the excitation is increased a series of period doubling bifurcations occurs. The nonlinear dynamics of the oscillating bubble cluster are observed to follow a subharmonic route to chaos

How can there be open access to journal articles?

The possibility of open access to journal literature has generated considerable discussion in the academic, publishing and library communities. The discussion has largely centred not on the desirability of open access in principle but upon its practicability and its effect upon the traditional journal publication system. This article will examine points made in the public discussion of the two major routes to open access outlined in the Budapest Open Access Initiative (BOAI), author self-archiving in academic repositories and the publication of journals using new toll-free economic models. Issues both for and against open access have been raised by authors, by publishers and by librarians, and a realistic approach to the feasibility of open access is important. The conclusion reached will be that open access to journal literature is feasible through either BOAI strategy but that more investigation is needed of both the positive and the negative messages received from stakeholders with as much experimentation of different models as possible