Resolving identities: Successive crises in a trading room after 9/11

How do organizations cope with extreme uncertainty? The existing literatureis divided on this issue: some argue that organizations deal best withuncertainty in the environment by reproducing it in the organization, whereasothers contend that the orga nization should be protected from theenvironment. In this paper we study the case of a Wall Street investment bankthat lost its entire office and trading technology in the terrorist attack ofSeptember 11 th. The traders survived, but were forced to relocate to amakeshift trading room in New Jersey. During the six months the traders spentoutside New York City, they had to deal with fears and insecurities insidethe company as well as outside it: anxiety about additional attacks,questions of professional identity, doubts about the future of the firm, andambiguities about the future re-location of the trading room. The firmovercame these uncertainties by protecting the traders identities and theirability to engage in sensemaking. The organization held together through aleadership style that managed ambiguities and created the conditions for newsolutions to emerge.

Pensamiento geográfico versus teoría de la comunicación. Hacia un modelo de análisis comunicativo del paisaje

El estudio de las implicaciones comunicativas presentes en el paisaje abre un amplio abanico de posibilidades para el tratamiento de la dualidad entre comunicación y paisaje. Aspectos como los efectos que el paisaje genera en los procesos de comunicación humana (comunicación intrapersonal e interpersonal), el seguimiento de los procesos comunicativos mediante los cuales se mercadea con el paisaje (comunicación de masas), la construcción de imaginarios individuales y colectivos a partir de la interacción entre ciudadanía y paisaje y, más recientemente, la construcción de identidades territoriales a partir de la elaboración de una imagen de marca de ciudad o de país —léase promoción turística, citymarketing y/o branding— tienen, todos ellos, unas enormes implicaciones en las sociedades contemporáneas. Es por todo ello por lo que se hace imprescindible avanzar hacia un modelo de análisis comunicativo del paisaje, objetivo posible interrelacionando la geografía y los estudios de comunicación, dos disciplinas aparentemente alejadas una de la otra en cuanto a sus orígenes y su praxis y, sin embargo, muy cercanas en lo que respecta a la evolución reciente de sus paradigmas y en lo referente al tratamiento de determinados conceptos, como los de espacio y paisaje.

Surface collective oscillations of metal clusters and spheres: Random-phase-approximation sum-rules approach

Using the once and thrice energy-weighted moments of the random-phase-approximation strength function, we have derived compact expressions for the average energy of surface collective oscillations of clusters and spheres of metal atoms. The L=0 volume mode has also been studied. We have carried out quantal and semiclassical calculations for Na and Ag systems in the spherical-jellium approximation. We present a rather thorough discussion of surface diffuseness and quantal size effects on the resonance energies.

Delocalization and fragmentation of collective modes in doped 4He drops

We have investigated the fragmentation of collective modes in doped 4He drops in the framework of a finite-range density-functional theory, as well as the delocalization of the impurity inside the cluster. Our results indicate that the impurity is gradually delocalized inside the drop as the size of the latter increases. As an example, results are shown in the case of Xe-4HeN systems up to N=112.

Collective states of 3He clusters

The monopole (L=0) and quadrupole (L=2) strength distributions in normal 3He clusters are calculated within the random-phase approximation. We use a phenomenological, zero-range 3-3He interaction to generate the Hartree-Fock single-particle spectrum and the residual particle-hole interaction. The evolution of the collective modes with the number of atoms in the cluster is discussed.

Collective and single-particle excitations of a trapped Bose gas

The density of states of a Bose-condensed gas confined in a harmonic trap is investigated. The predictions of Bogoliubov theory are compared with those of Hartree-Fock theory and of the hydrodynamic model. We show that the Hartree-Fock scheme provides an excellent description of the excitation spectrum in a wide range of energy, revealing a major role played by single-particle excitations in these confined systems. The crossover from the hydrodynamic regime, holding at low energies, to the independent-particle regime is explicitly explored by studying the frequency of the surface mode as a function of their angular momentum. The applicability of the semiclassical approximation for the excited states is also discussed. We show that the semiclassical approach provides simple and accurate formulas for the density of states and the quantum depletion of the condensate.

Temperature-induced resonances and Landau damping of collective modes in Bose-Einstein condensed gases in spherical traps

Interaction between collective monopole oscillations of a trapped Bose-Einstein condensate and thermal excitations is investigated by means of perturbation theory. We assume spherical symmetry to calculate the matrix elements by solving the linearized Gross-Pitaevskii equations. We use them to study the resonances of the condensate induced by temperature when an external perturbation of the trapping frequency is applied and to calculate the Landau damping of the oscillations.

Collective spin excitations of alkali-metal clusters

The response function of alkali-metal clusters, modeled as jellium spheres, to dipole (L=1) and quadrupole (L=2) spin-dependent fields is obtained within the time-dependent local-spin-density approximation of density-functional theory. We predict the existence of low-energy spin modes of surface type, which are identified from the strength function. Their collectivity and evolution with size are discussed.

Collective dynamic properties in simple crystals: Influence of the structural disorder

Collective dynamic properties in Lennard-Jones crystals are investigated by molecular dynamics simulation. The study is focused on properties such as the dynamic structure factors, the longitudinal and transverse currents and the density of states. The influence on these properties of the structural disorder is analyzed by comparing the results for one-component crystals with those for liquids and supercooled liquids at analogous conditions. The effects of species-disorder on the collective properties of binary crystals are also discussed.

Comment on "Neutron brillouin scattering study of collective dynamics in a dense He-Ne gaseous mixture"

A Comment on the Letter by Ubaldo Bafile, et al., Phys. Rev. Lett. 86, 1019 (2001). The authors of the Letter offer a Reply.

Absence of collective effects in Heisenberg systems with localized magnetic moments

Existence of collective effects in magnetic coupling in ionic solids is studied by mapping spin eigenstates of the Heisenberg and exact nonrelativistic Hamiltonians on cluster models representing KNiF3, K2NiF4, NiO, and La2CuO4. Ab initio techniques are used to estimate the Heisenberg constant J. For clusters with two magnetic centers, the values obtained are about the same for models having more magnetic centers. The absence of collective effects in J strongly suggests that magnetic interactions in this kind of ionic solids are genuinely local and entangle only the two magnetic centers involved.

Embodying feminist research: learning from action research, political practices, diffractions and collective knowledge.

In the past three decades, feminists and critical theorists have discussed and argued the importance of deconstructing and problematizing social science research methodology in order to question normalized hierarchies concerning the production of knowledge and the status of truth claims. Nevertheless, often, these ideas have basically remained theoretical propositions not embodied in research practices. In fact there is very little published discussion about the difficulties and limits of their practical application. In this paper we introduce some interconnected reflections starting from two different but related experiences of embodying 'feminist activist research'. Our aim is to emphasise the importance of attending to process, making mistakes and learning during fieldwork, as well as experimenting with personalized forms of analysis, such as the construction of narratives and the story-telling process.

Embodying feminist research: learning from action research, political practices, diffractions and collective knowledge.

In the past three decades, feminists and critical theorists have discussed and argued the importance of deconstructing and problematizing social science research methodology in order to question normalized hierarchies concerning the production of knowledge and the status of truth claims. Nevertheless, often, these ideas have basically remained theoretical propositions not embodied in research practices. In fact there is very little published discussion about the difficulties and limits of their practical application. In this paper we introduce some interconnected reflections starting from two different but related experiences of embodying 'feminist activist research'. Our aim is to emphasise the importance of attending to process, making mistakes and learning during fieldwork, as well as experimenting with personalized forms of analysis, such as the construction of narratives and the story-telling process.