Search

For a large class of irreducible shift spaces $X\subset\tA^{\Z^d}$, with $\tA$ a finite alphabet, and for absolutely summable potentials $\Phi$, we prove that equilibrium measures for $\Phi$ are weak Gibbs measures. In particular, for $d=1$, the result holds for irreducible sofic shifts.

In a number of embryonic systems, centrosomes that have lost their association with the nuclear envelope and spindle maintain their ability to duplicate and induce astral microtubules. To identify additional activities of free centrosomes, we monitored astral microtubule dynamics by injecting living syncytial Drosophila embryos with fluorescently labeled tubulin. Our recordings follow multiple rounds of free centrosome duplication and separation during the cortical division. The rate and distance of free sister centrosome separation corresponds well with the initial phase of associated centrosome separation. However, the later phase of separation observed for centrosomes associated with a spindle (anaphase B) does not occur. Free centrosome separation regularly occurs on a plane parallel to the plasma membrane. While previous work demonstrated that centrosomes influence cytoskeletal dynamics, this observation suggests that the cortical cytoskeleton regulates the orientation of centrosome separation. Although free centrosomes do not form spindles, they display relatively normal cell cycle-dependent modulations of their astral microtubules. In addition, free centrosome duplication, separation, and modulation of microtubule dynamics often occur in synchrony with neighboring associated centrosomes. These observations suggest that free centrosomes respond normally to local nuclear division signals. Disruption of the cortical nuclear divisions with aphidicolin supports this conclusion; large numbers of abnormal nuclei recede into the interior while their centrosomes remain on the cortex. Following individual free centrosomes through multiple focal planes for 45 min after the injection of aphidicolin reveals that they do not undergo normal modulation of their astral dynamics nor do they undergo multiple rounds of duplication and separation. We conclude that in the absence of normally dividing cortical nuclei many centrosome activities are disrupted and centrosome duplication is extensively delayed. This indicates the presence of a feedback mechanism that creates a dependency relationship between the cortical nuclear cycles and the centrosome cycles.

When the present state architect took office on March r, 1923, he was immediately confronted with the necessity of making certain decisions with respect to plans for new buildings then in course of preparation. As these buildings were in every case merely parts of hospitals already designed and in most cases constructed and operating, the decisions seemed clearly to call for consideration of the working relationships between these new buildings and the others constituting the hospital. In giving consideration to these matters the state architect first discovered that his past experience with the design of general hospitals was of little or no value because those requirements for the treatment and care of the physically sick which are basic in the design of a general hospital are of very minor importance in the design of a hospital for the mentally sick. Certain fundamental differences between the considerations underlying the design of a general hospital and those underlying the design of a hospital for insane became increasingly apparent. For example, the period of patient turn-over in the hospitals for the insane is several years instead of a few weeks as in the case of a general hospital. Here was introduced a consideration of proper care and custody of patients over the long period as entirely separate from considerations of their medical treatment. It became apparent to the state architect that, after all, these great hospitals for the insane fundamentally are not unlike industrial plants. They are in reality processing materials to produce a certain desired result-or ought to be. A study of the statistics relating to the patient population in the hospitals of the State of New York seemed to fully justify this assumption. The percentages of male and female patients in each of the several hospitals

We give a necessary and sufficient condition on beta of the natural extension of a beta-shift, so that any equilibrium measure for a function of bounded total oscillations is a weak Gibbs measure., Comment: 16 pages

For the spaceXin a large class of finite alphabet shift spaces (lattice models) and the class of functionsfwith bounded total oscillations, we prove that each equilibrium measure nu atf=phi is a weak Gibbs measures for phi-P(phi). In addition, the empirical measures satisfy a full large deviations principle for (X,nu).