Uma Visão da Empresa Baseada em Habilidades: Contextos Estratégicos e Contingenciais

This paper extends the corporation-based metaphor of the tree by proposing that cognition is the core ability which contributes to nourishing the development of core competencies in the organization. From such an extension, this paper takes a raises the following question: What is the role of cognition in the organization that is in the pursuit of core competencies and sustainable competitive advantage? This paper answers this problem by presenting two perspectives that contribute toward introducing the field of organizational cognition into the domains of the resource-based view and contingency. First, it proposes an ability-based view of the organization through analogies which are most associated with the concepts of the resource-based view and dynamic capabilities of the firm. Second, it proposes a contingency-based view of organizational cognition which is most developed through causal relations and also deductive and inductive reasoning. Grounded in these perspectives, this study sustains the thesis that cognition is a source of controlling environmental uncertainty and, complementarily, cognition contributes toward creating and sustaining the organization’s competitive advantage

Quantum Control of the Hyperfine Spin of a Cs Atom Ensemble

We demonstrate quantum control of a large spin-angular momentum associated with the F=3 hyperfine ground state of 133Cs. A combination of time dependent magnetic fields and a static tensor light shift is used to implement near-optimal controls and map a fiducial state to a broad range of target states, with yields in the range 0.8-0.9. Squeezed states are produced also by an adiabatic scheme that is more robust against errors. Universal control facilitates the encoding and manipulation of qubits and qudits in atomic ground states, and may lead to improvement of some precision measurements.Comment: 4 pages, 4 figures (color

In--out intermittency in PDE and ODE models

We find concrete evidence for a recently discovered form of intermittency, referred to as in--out intermittency, in both PDE and ODE models of mean field dynamos. This type of intermittency (introduced in Ashwin et al 1999) occurs in systems with invariant submanifolds and, as opposed to on--off intermittency which can also occur in skew product systems, it requires an absence of skew product structure. By this we mean that the dynamics on the attractor intermittent to the invariant manifold cannot be expressed simply as the dynamics on the invariant subspace forcing the transverse dynamics; the transverse dynamics will alter that tangential to the invariant subspace when one is far enough away from the invariant manifold. Since general systems with invariant submanifolds are not likely to have skew product structure, this type of behaviour may be of physical relevance in a variety of dynamical settings. The models employed here to demonstrate in--out intermittency are axisymmetric mean--field dynamo models which are often used to study the observed large scale magnetic variability in the Sun and solar-type stars. The occurrence of this type of intermittency in such models may be of interest in understanding some aspects of such variabilities.Comment: To be published in Chaos, June 2001, also available at http://www.eurico.web.co

Cerebral edema in a patient following cytoreductive surgery and hyperthermic intraoperative intraperitoneal chemoperfusion

BACKGROUND: Cytoreductive surgery and intraoperative, intraperitoneal hyperthermic chemoperfusion (HIPEC) is increasingly used to treat peritoneal surface metastases. We describe a fatal case of cerebral edema in a patient with appendiceal carcinoma and an underlying seizure disorder who underwent cytoreductive surgery and HIPEC. CASE PRESENTATION: A case of fatal postoperative cerebral edema is presented in a patient with an underlying seizure disorder and recurrent mucinous adenocarcinoma of the appendix. The patient was treated with cytoreductive surgery and intraoperative intraperitoneal hyperthermic chemoperfusion. The details and implications of this complication are discussed. CONCLUSION: The recognition of this potential complication is important for physicians performing cytoreductive surgery and HIPEC. Special caution should be taken when patients with seizure disorders are being considered for this treatment

Flux expulsion with dynamics

In the process of flux expulsion, a magnetic field is expelled from a region of closed streamlines on a TR1/3 m time scale, for magnetic Reynolds number Rm ≫ 1 (T being the turnover time of the flow). This classic result applies in the kinematic regime where the flow field is specified independently of the magnetic field. A weak magnetic ‘core’ is left at the centre of a closed region of streamlines, and this decays exponentially on the TR1/2 m time scale. The present paper extends these results to the dynamical regime, where there is competition between the process of flux expulsion and the Lorentz force, which suppresses the differential rotation. This competition is studied using a quasi-linear model in which the flow is constrained to be axisymmetric. The magnetic Prandtl number Rm/Re is taken to be small, Rm large, and a range of initial field strengths b0 is considered. Two scaling laws are proposed and confirmed numerically. For initial magnetic fields below the threshold bcore = O(UR−1/3 m ), flux expulsion operates despite the Lorentz force, cutting through field lines to result in the formation of a central core of magnetic field. Here U is a velocity scale of the flow and magnetic fields are measured in Alfv´en units. For larger initial fields the Lorentz force is dominant and the flow creates Alfv´en waves that propagate away. The second threshold is bdynam = O(UR−3/4 m ), below which the field follows the kinematic evolution and decays rapidly. Between these two thresholds the magnetic field is strong enough to suppress differential rotation leaving a magnetically controlled core spinning in solid body motion, which then decays slowly on a time scale of order TRm

Effect of ligand methylation on the spin-switching properties of surface-supported spin-crossover molecules

X-ray absorption spectroscopy investigations of the spin-state switching of spin-crossover (SCO) complexes adsorbed on a highly-oriented pyrolytic graphite (HOPG) surface have shown so far that HOPG is a promising candidate to realize applications such as spintronic devices because of the stability of SCO complexes on HOPG and the possibility of highly efficient thermal and light-induced spin-state switching. Herein, we present the spin switching of several Fe(II) SCO complexes adsorbed on an HOPG surface with particular emphasis on the thermally induced spin transition behaviour with respect to different structural modifications. The complexes of the type [Fe(bpz)2(L)] (bpz  =  dihydrobis(pyrazolyl)borate, L  =  1,10-phenanthroline, 2,2'-bipyridine) and their methylated derivatives exhibit SCO in the solid state with some differences regarding cooperative effects. However, in the vacuum-deposited thick films on quartz, complete and more gradual spin transition behavior is observable via UV/vis spectroscopy. In contrast to that, all complexes show large differences upon direct contact with HOPG. Whereas the unmodified complexes show thermal and light-induced SCO, the addition of e.g. two or four methyl groups leads to a partial or a complete loss of the SCO on the surface. The angle-dependent measurement of the N K-edge compared to calculations indicates that the complete SCO and HS-locked molecules on the surface exhibit a similar preferential orientation, whereas complexes undergoing an incomplete SCO exhibit a random orientation on the surface. These results are discussed in the light of molecule-substrate interactions

Molecular Basis for the Anchoring of Proto-Oncoprotein Nup98 to the Cytoplasmic Face of the Nuclear Pore Complex

The cytoplasmic filament nucleoporins of the nuclear pore complex (NPC) are critically involved in nuclear export and remodeling of mRNA ribonucleoprotein particles and are associated with various human malignancies. Here, we report the crystal structure of the Nup98 C-terminal autoproteolytic domain, frequently missing from leukemogenic forms of the protein, in complex with the N-terminal domain of Nup82 and the C-terminal tail fragment of Nup159. The Nup82 β propeller serves as a noncooperative binding platform for both binding partners. Interaction of Nup98 with Nup82 occurs through a reciprocal exchange of loop structures. Strikingly, the same Nup98 groove promiscuously interacts with Nup82 and Nup96 in a mutually excusive fashion. Simultaneous disruption of both Nup82 interactions in yeast causes severe defects in mRNA export, while the severing of a single interaction is tolerated. Thus, the cytoplasmic filament network of the NPC is robust, consistent with its essential function in nucleocytoplasmic transport

Bounds on the Satisfiability Threshold for Power Law Distributed Random SAT

Propositional satisfiability (SAT) is one of the most fundamental problems in computer science. The worst-case hardness of SAT lies at the core of computational complexity theory. The average-case analysis of SAT has triggered the development of sophisticated rigorous and non-rigorous techniques for analyzing random structures. Despite a long line of research and substantial progress, nearly all theoretical work on random SAT assumes a uniform distribution on the variables. In contrast, real-world instances often exhibit large fluctuations in variable occurrence. This can be modeled by a scale-free distribution of the variables, which results in distributions closer to industrial SAT instances. We study random k-SAT on n variables, m = Theta(n) clauses, and a power law distribution on the variable occurrences with exponent beta. We observe a satisfiability threshold at beta = (2k-1)/(k-1). This threshold is tight in the sense that instances with beta 0 are unsatisfiable with high probability (w.h.p.). For beta >= (2k-1)/(k-1)+epsilon, the picture is reminiscent of the uniform case: instances are satisfiable w.h.p. for sufficiently small constant clause-variable ratios m/n; they are unsatisfiable above a ratio m/n that depends on beta