title: The Spatial association of a doctor and his patients in Hamilton city

authors: Judd, Edward Walter Bruce

abstract: Information which has been diffused through a population about an idea has been accepted, and the idea adopted, by some members of the population under some circumstances (Hagerstrand, 1967.) 
The spatial relationship between a doctor and his patients in Hamilton City were examined to see if information about this particular doctor, when diffused through the urban residential area, had been the basis for a significant number of his patients attending his surgery rather than the surgery of the doctor nearest to them.

text: The Spatial association of a doctor and his patients in Hamilton city Information which has been diffused through a population about an idea has been accepted, and the idea adopted, by some members of the population under some circumstances (Hagerstrand, 1967.) 
The spatial relationship between a doctor and his patients in Hamilton City were examined to see if information about this particular doctor, when diffused through the urban residential area, had been the basis for a significant number of his patients attending his surgery rather than the surgery of the doctor nearest to them.

year: 1971

title: Toward a theory of the general-anesthetic-induced phase transition of the cerebral cortex. I. A thermodynamics analogy

authors: Steyn-Ross, Moira L.

subjects: thermodynamics

abstract: In a recent paper the authors developed a stochastic model for the response of the cerebral cortex to a general anesthetic agent. The model predicted that there would be an anesthetic-induced phase change at the point of transition into unconsciousness, manifested as a divergence in the electroencephalogram spectral power, and a change in spectral energy distribution from being relatively broadband in the conscious state to being strongly biased towards much lower frequencies in the unconscious state. Both predictions have been verified in recent clinical measurements. In the present paper we extend the model by calculating the equilibrium distribution function for the cortex, allowing us to establish a correspondence between the cortical phase transition and the more familiar thermodynamic phase transitions. This correspondence is achieved by first identifying a cortical free energy function, then by postulating that there exists an inverse relationship between an anesthetic effect and a quantity we define as cortical excitability, which plays a role analogous to temperature in thermodynamic phase transitions. We follow standard thermodynamic theory to compute a cortical entropy and a cortical “heat capacity,” and we investigate how these will vary with anesthetic concentration. The significant result is the prediction that the entropy will decrease discontinuously at the moment of induction into unconsciousness, concomitant with a release of “latent heat” which should manifest as a divergence in the analogous heat capacity. There is clear clinical evidence of heat capacity divergence in historical anesthetic-effect measurements performed in 1977 by Stullken et al. [Anesthesiology 46, 28 (1977)]. The discontinuous step change in cortical entropy suggests that the cortical phase transition is analogous to a first-order thermodynamic transition in which the comatose-quiescent state is strongly ordered, while the active cortical state is relatively disordered.

text: Toward a theory of the general-anesthetic-induced phase transition of the cerebral cortex. I. A thermodynamics analogy In a recent paper the authors developed a stochastic model for the response of the cerebral cortex to a general anesthetic agent. The model predicted that there would be an anesthetic-induced phase change at the point of transition into unconsciousness, manifested as a divergence in the electroencephalogram spectral power, and a change in spectral energy distribution from being relatively broadband in the conscious state to being strongly biased towards much lower frequencies in the unconscious state. Both predictions have been verified in recent clinical measurements. In the present paper we extend the model by calculating the equilibrium distribution function for the cortex, allowing us to establish a correspondence between the cortical phase transition and the more familiar thermodynamic phase transitions. This correspondence is achieved by first identifying a cortical free energy function, then by postulating that there exists an inverse relationship between an anesthetic effect and a quantity we define as cortical excitability, which plays a role analogous to temperature in thermodynamic phase transitions. We follow standard thermodynamic theory to compute a cortical entropy and a cortical “heat capacity,” and we investigate how these will vary with anesthetic concentration. The significant result is the prediction that the entropy will decrease discontinuously at the moment of induction into unconsciousness, concomitant with a release of “latent heat” which should manifest as a divergence in the analogous heat capacity. There is clear clinical evidence of heat capacity divergence in historical anesthetic-effect measurements performed in 1977 by Stullken et al. [Anesthesiology 46, 28 (1977)]. The discontinuous step change in cortical entropy suggests that the cortical phase transition is analogous to a first-order thermodynamic transition in which the comatose-quiescent state is strongly ordered, while the active cortical state is relatively disordered.

year: 2001

title: Ka Māpuna: Towards a rangatiratanga framework for the governance of waterways

authors: Martin, Betsan

abstract: Rangatiratanga is thenavigational courseforthis research, the aspiration that guides a frameworkfor thegovernance which, in respect ofwaterways and Te Taiao secures mauri, ecosystem health, and water for domestic and commercial use. Rangatiratanga encompasses mana whakahaeredecision-making throughout all relevantgovernance systems. In respect of resource governance, this needs to be achieved through mana whenua authorities and co-governance institutions and procedures.

text: Ka Māpuna: Towards a rangatiratanga framework for the governance of waterways Rangatiratanga is thenavigational courseforthis research, the aspiration that guides a frameworkfor thegovernance which, in respect ofwaterways and Te Taiao secures mauri, ecosystem health, and water for domestic and commercial use. Rangatiratanga encompasses mana whakahaeredecision-making throughout all relevantgovernance systems. In respect of resource governance, this needs to be achieved through mana whenua authorities and co-governance institutions and procedures.

year: 2021