The Effect of Organizational Context on Individual Performance

Several observers have suggested that highly skilled workers convey little in the way of competitive advantage for firms due to their mobility. Implicit in this view is the belief that organizations are not important in determining the performance of such individuals. In this study, we address this issue by examining skilled individuals who work within multiple organizations roughly simultaneously. Specifically, we consider the performance of cardiac surgeons, many of whom perform operations at multiple hospitals during the course of a given year. Using patient mortality as an outcome measure, we find that the quality of a surgeon's performance at a given hospital improves significantly with increases in his or her annual procedure volume at that hospital but does not significantly improve with increases in his or her volume at other hospitals. Our findings suggest that surgeon performance is not fully portable across hospitals (i.e., some portion of performance is firm specific). We consider the implications of our results for settings beyond health care.

Comment on ``Majoron emitting neutrinoless double beta decay in the electroweak chiral gauge extensions''

We point out that if the majoron-like scheme is implemented within a 331 model, there must exist at least three different mass scales for the scalar vacuum expectation values in the model.Comment: 4 pages, no figures, Revtex. To be published in Physical Review

Electromagnetic Hadron Form Factors and Higher Fock Components

Investigation of the spacelike and timelike electromagnetic form factors of hadrons, within a relativistic microscopical model characterized by a small set of hypothesis, could shed light on the components of hadron states beyond the valence one. Our relativistic approach has been successfully applied first to the pion and then the extension to the nucleon has been undertaken. The pion case is shortly reviewed as an illustrative example for introducing the main ingredients of our approach, and preliminary results for the nucleon in the spacelike range $-10 (GeV/c)^2\le q^2 \le 0$ are evaluated.Comment: 8 pages, 6 figs, espcrc1.sty included. Proceedings of Fifth International Conference on Perspectives In Hadronic Physics, ICTP, May 22-26, 200

Timelike and spacelike hadron form factors, Fock state components and light-front dynamics

A unified description of spacelike and timelike hadron form factors within a light-front model was successfully applied to the pion. The model is extended to the nucleon to study the role of $q \bar q$ pair production and of nonvalence components in the nucleon form factors. Preliminary results in the spacelike range $0 \le Q^2 \le 10 ~ (GeV/c)^2$ are presented.Comment: 4 pages, espcrc1.sty. proceedings of FB XVIII (August 2006, Brazil), to be published in Nucl. Phys.

Two-Port Stacked Piezoelectric Aluminum Nitride Contour-Mode Resonant MEMS

This paper reports on design, fabrication and experimental testing of a new class of two-port stacked piezoelectric aluminum nitride contour-mode micromechanical resonators that can be used for RF filtering and timing applications. This novel design consists of two layers of thin film AlN stacked on top of each other and excited in contour mode shapes using the d31 piezoelectric coefficient. Main feature of this design is the ability to reduce capacitive parasitic feedthrough between input and output signals while maintaining strong electromechanical coupling. For example, these piezoelectric contour-mode resonators show a quality factor of 1,700 in air and a motional resistances as low as 175 Ω at a frequency of 82.8 MHz. The input to output capacitance has been limited to values below 80 fF, therefore simplifying signal detection even at high frequencies

Minimal extended flavor groups, matter fields chiral representations, and the flavor question

We show the specific unusual features on chiral gauge anomalies cancellation in the minimal, necessarily 3-3-1, and the largest 3-4-1 weak isospin chiral gauge semisimple group leptoquark-bilepton extensions of the 3-2-1 conventional standard model of nuclear and electromagnetic interactions. In such models a natural explanation for the fundamental question of fermion generation replication arises from the self-consistency of a local gauge quantum field theory, which constrains the number of the QFD fermion families to the QCD color charges.Comment: 10 pages. <[email protected]

Electromagnetic form factors of the nucleon in spacelike and timelike regions

An approach for a unified description of the nucleon electromagnetic form factors in spacelike and timelike regions is presented. The main ingredients of our model are: $i)$ a Mandelstam formula for the matrix elements of the nucleon electromagnetic current; $ii)$ a 3-dimensional reduction of the problem on the Light-Front performed within the so-called {\tt Propagator Pole Approximation} ({\bf PPA}), which consists in disregarding the analytical structure of the Bethe-Salpeter amplitudes and of the quark-photon vertex function in the integration over the minus components of the quark momenta; $iii)$ a dressed photon vertex in the $q\bar{q}$ channel, where the photon is described by its spin-1, hadronic component.Comment: 8 pages, 9 figs., macro added. Proceedings of the XI Conf. on Problems in Theoretical Nuclear Physics, Cortona, Oct. 11-14, 200

UK Fashion Designers Working in Micro-sized Enterprises; Attitudes to Locational Resources, Their Peers and the Market

This paper contributes to an understanding of the importance of locally based resources and interactions in a globalised industry, fashion design. It examines the product design stage of the fashion production chain, rather than the manufacture and commercialisation of apparel products. We studied the use of their geographies by UK-based fashion designers working in micro-sized enterprises ( < 10 employees) especially because of their likely sensitivity to various aspects of proximity, including their dependence on external resources to supplement their own. Factor and cluster analysis identified four different types of designers, which differed in the manner in which they interacted with peers and markets, and accessed location-based resources. The paper advances explanations for the patterns of behaviour observed in the various clusters, and in making recommendations for further research predicts the types of design position each is likely to prefer

Control and ultrasonic actuation of a gas-liquid interface in a microfluidic chip

This article describes the design and manufacturing of a microfluidic chip, allowing for the actuation of a gas-liquid interface and of the neighboring fluid. A first way to control the interface motion is to apply a pressure difference across it. In this case, the efficiency of three different micro-geometries at anchoring the interface is compared. Also, the critical pressures needed to move the interface are measured and compared to theoretical result. A second way to control the interface motion is by ultrasonic excitation. When the excitation is weak, the interface exhibits traveling waves, which follow a dispersion equation. At stronger ultrasonic levels, standing waves appear on the interface, with frequencies that are half integer multiple of the excitation frequency. An associated microstreaming flow field observed in the vicinity of the interface is characterized. The meniscus and associated streaming flow have the potential to transport particles and mix reagents