1,095 research outputs found
An attention-based view of short-termism:The effects of organizational structure
Debates about short-termism in business tend to center around the role of shareholder pressures and managers’ incentives, while the role of organizational structure remains understudied. In our paper, we adopt an attention-based lens to elucidate the role of organizational structure in directing the attention of management towards pressures for short-term results at the expense of the long term. Specifically, we argue that greater scale of operations, hierarchy, bureaucracy, and workforce flexibility reduce slack resources available to senior managers and increase the complexity of information presented to them in different ways. As a result, the senior managers shift their attention to short-term pressures, which are more easily understood, at the expense of attention for long-term considerations. Analysis based on a survey of senior managers in 3221 private firms in the Netherlands provides support for our arguments
Pioneering the human development revolution: Analysing the trajectory of Mahbub ul Haq
Mahbub ul Haq's work to coordinate, establish and propagate the human development approach offers an example of effective leadership in promoting more ethical socio-economic development. This article reviews Pioneering the Human Development Revolution-An Intellectual Biography of Mahbub ul Haq (edited by Haq and Ponzio), and extends themes from the United Nations Intellectual History Project to examine Haq's contributions in terms of four aspects of leadership: articulating and applying values that combine depth with broad appeal; providing a fruitful and vivid way of seeing, a 'vision', that reflects the values; embodying the values and vision in workable practical proposals; and supporting and communicating the previous aspects through wide and relevant networks. It suggests that the human development approach may need to update its values and vision, including through better integration of human security thinking, if it is to retain the leadership role it acquired thanks to Haq
A study of frequency and pulses for stepper motor controller system by using programmable logic controller
The stepper motor movement process produced different frequency and pulses. This research explained about the frequency and pulses for the stepper motor movement by using Programmable Logic Controller (PLC) as research method. The study was done to find the suitable frequency and pulses for stepper motor movement by developing a prototype stepper motor controller system. The pulse frequency used did not affected the distance of moving load in the stepper motor operations. The increasing number of pulse frequency only will affect the time taken for the stepper motor to complete its operations. The result showed that number of pulse frequency at high operation was 5000 Hz. Pulse number reacted as a manipulated variable that affected both factor which is time taken of stepper motor operation and the distance of moving load
Transformation optics for antennas: why limit the bandwidth with metamaterials?
This work is part funded by the Ministry of Defence and is published with the permission of
the Defence Science and Technology Laboratory on behalf of the Controller of HMSO
Dislocation dynamics: from microscopic models to macroscopic crystal plasticity
In this paper we study the connection between four models describing
dislocation dynamics: a generalized 2D Frenkel-Kontorova model at the atomic
level, the Peierls-Nabarro model, the discrete dislocation dynamics and a
macroscopic model with dislocation densities. We show how each model can be
deduced from the previous one at a smaller scale
Characterization of the multidrug efflux transporter styMdtMfrom Salmonella enterica serovar Typhi
Salmonellae are foodborne pathogens and the major cause of gastroenteritis in humans. Salmonellae express multidrug efflux transporters that play a key role in their drug resistance, which is becoming an increasing problem for therapeutic intervention. Despite their biomedical importance, the mechanisms underlying substrate transport by multidrug efflux transporters remain poorly understood. Here, we describe the first characterization of a multidrug transporter belonging to the major facilitator superfamily from the genus Salmonella. We show that several clinical Salmonella Typhi (S. Typhi) isolates constitutively express the styMdtM (STY4874) gene, which encodes a known multidrug-resistance (MDR) transporter. Guided by the structure of the Escherichia coli (E. coli) homolog, we studied two residues critical for substrate transport, Asp25 and Arg111. Mutation of Asp25 to glutamate did not affect the transport function of styMdtM, whereas mutation to alanine reduced its transport activity, suggesting that a negative charge at this position is critical for substrate translocation across the membrane. Substrate-affinity measurements by intrinsic fluorescence spectroscopy showed that the Asp25Ala mutant retained its capacity to bind substrate, albeit at a lower level. Mutation of Arg111 to alanine resulted in a decrease in secondary structure content of the transporter, and mutation to lysine completely destabilized the structure of the transporter. A homology model of styMdtM suggests that Arg111 is important for stabilizing the transmembrane domain by mediating necessary interactions between neighboring helices. Together, our studies provide new structural and mechanistic insights into the Salmonella MDR transporter styMdtM
Modeling Complex Nuclear Spectra - Regularity versus Chaos
A statistical analysis of the spectrum of two particle - two hole doorway
states in a finite nucleus is performed. On the unperturbed mean-field level
sizable attractive correlations are present in such a spectrum. Including
particle-hole rescattering effects via the residual interaction introduces
repulsive dynamical correlations which generate the fluctuation properties
characteristic of the Gaussian Orthogonal Ensemble. This signals that the
underlying dynamics becomes chaotic. This feature turns out to be independent
of the detailed form of the residual interaction and hence reflects the generic
nature of the fluctuations studied.Comment: 8 pages of text (LATEX), figures (not included, available from the
authors), Feb 9
From Regular to Chaotic States in Atomic Nuclei
An interesting aspect of nuclear dynamics is the co--existence, in atomic
nuclei, of regular and chaotic states. In the first part of the present work,
we review the state of the art of nuclear dynamics and use a schematic shell
model to show how a very simple and schematic nucleon--nucleon interaction can
produce an orderchaos transition. The second part is devoted to a
discussion of the wave function behaviour and decay of chaotic states using
some simple models (to be published in Rivista Nuovo Cimento).Comment: 65 pages, LaTex (the figures are not included), Preprint
DFPD/94/TH/26, University of Padov
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