Understanding the Drivers of Urban Expansion: Case Study of Seville Province

Urban development has accelerated across the globe in recent decades. Much of this development has not been concentrated in cities, but has occurred as dispersed, low-density development outside of major centers but within their area of economic influence, along transport networks, in coastal areas, or close to areas of high natural value. This research focuses on the case study of the province of Seville, Spain, which has experienced notable urban expansion in recent years. We present a systems approach to model dependence between economic development and distribution of urban and non-urban land in this region from data collection to model validation. An extensive search of available indicators of socioeconomic development in this region has been carried out. We apply this data to create a generic statistical model of urban expansion, which links land-use patterns with population density and other indicators of economic growth. The model is tested across the whole Seville region and in its sub-regions to derive drivers of urban expansion in this territory

Relative entropy as a measure of inhomogeneity in general relativity

We introduce the notion of relative volume entropy for two spacetimes with preferred compact spacelike foliations. This is accomplished by applying the notion of Kullback-Leibler divergence to the volume elements induced on spacelike slices. The resulting quantity gives a lower bound on the number of bits which are necessary to describe one metric given the other. For illustration, we study some examples, in particular gravitational waves, and conclude that the relative volume entropy is a suitable device for quantitative comparison of the inhomogeneity of two spacetimes.Comment: 15 pages, 7 figure

Failure of preoperative C. parvum vaccine to modify secondary disease following excision of two non-immunogenic murine carcinomas.

Sadler and Castro (1976) reported that a single dose of C. parvum vaccine given i.p. or i.v. to mice 4 days before excision of subcutaneous transplants of Lewis lung carcinoma significantly reduced the incidence of lung metastases in the operated mice. In similarly designed experiments, using 2 different carcinomas of spontaneous origin in our own inbred mouse colonies, we were unable to demonstrate any influence of C. parvum vaccine on the incidence or latent period of secondary disease in operated mice. We discuss possible reasons for our failure to reproduce the findings of Sadler and Castro

Facilitation of nodal metastasis from a non-immunogenic murine carcinoma by previous whole-body irradiation of tumour recipients.

Of 193 CBA mice kept under prolonged observation after excision of small intradermal transplants of a non-immunogenic tumour (CBA Carcinoma NT), 27 (14%) presented with local recurrence, 19 (10%) with regional lymphnodal metastasis (RNM) and 72 (37%), with pulmonary metastasis +/- other systemic metastases. When mice were exposed to sublethal whole-body irradiation (WBI) before tumour transplantation, the incidence of RNM rose to approximately 80% and the latent period was reduced from approximately 60 days to approximately 40 days after tumour transplantation. This enhancement of RNM by WBI was undiminished when the interval between WBI and tumour transplantation was increased from 1 to 90 days. An explanation for this effect in terms of immunosuppression by the WBI is unlikely for the following reasons: the tumour was non-immunogenic by standard quantitative tests; the effect persisted long after the expected time for recovery of immune reactivity; and i.v. injection of normal marrow and lymphoid cells after WBI failed to reduce the effect. That the effect was systemic was proved by failure of local pre-irradiation of the tumour bed or regional node to enhance RNM. The effect was not observed when WBI was given 4 days after excision of tumours. These and other experiments failed to indicate the mechanism of the effect of WBI, but its long persistence suggests that it may relate to stored lethal radiation damage in migrating cells of slow turnover tissues

Further studies of the relationship between lymphatic dissemination and lymphnodal metastasis in non-immunogenic murine tumours.

In all 6 different murine tumours of spontaneous origin, a high proportion (22-95%) of the regional lympgh nodes draining small intradermal tumours gave rise to tumours after their isogeneic transplantation as whole nodes. In separate experiments with 4 of these tumours, equivalent tumour-bearing mice had their tumours surgically excised and were observed for the development of regional nodal corresponding frequency of tumour formation by transplanted nodes. After high-dose radiotherapy of intradermal carcinomas, there was a progressive fall in the incidence of positive regional node transplants from 48 to 96 h after irradiation. It is concluded that continual lymphatic dissemination of viable cancer cells is characteristic of malignant tumours, but that there is a relatively small chance of such cells giving rise to nodal metastatic growth. Related studies showed that the ability of a small number of cancer cells to give rise to tumours was very much greater if they were incorporated in a lymph node at transplantation than if they were transplanted directly as a suspension

Study of fluid transients in closed conduits annual report no. 1

Atmospheric density effect on computation of earth satellite orbit

Dispersal Dynamics in a Wind-Driven Benthic System

Bedload and water column traps were used with simultaneous wind and water velocity measurements to study postlarval macrofaunal dispersal dynamics in Manukau Harbour, New Zealand. A 12-fold range in mean wind condition resulted in large differences in water flow (12-fold), sediment flux (285-fold), and trap collection of total number of individuals (95-fold), number of the dominant infaunal organism (84-fold for the bivalve Macomona liliana), and number of species (4-fold). There were very strong, positive relationships among wind condition, water velocity, sediment flux, and postlarval dispersal, especially in the bedload. Local density in the ambient sediment was not a good predictor of dispersal. Results indicate that postlarval dispersal may influence benthic abundance pat- terns over a range of spatial scales

The Evolution of Finite Amplitude Wavetrains in Plane Channel Flow

We consider a viscous incompressible fluid flow driven between two parallel plates by a constant pressure gradient. The flow is at a finite Reynolds number, with an 0(l) disturbance in the form of a traveling wave. A phase equation approach is used to discuss the evolution of slowly varying fully nonlinear two dimensional wavetrains. We consider uniform wavetrains in detail, showing that the development of a wavenumber perturbation is governed by Burgers equation in most cases. The wavenumber perturbation theory, constructed using the phase equation approach for a uniform wavetrain, is shown to be distinct from an amplitude perturbation expansion about the periodic flow. In fact we show that the amplitude equation contains only linear terms and is simply the heat equation. We review, briefly, the well known dynamics of Burgers equation, which imply that both shock structures and finite time singularities of the wavenumber perturbation can occur with respect to the slow scales. Numerical computations have been performed to identify areas of the (wavenumber, Reynolds number, energy) neutral surface for which each of these possibilities can occur. We note that the evolution equations will breakdown under certain circumstances, in particular for a weakly nonlinear secondary flow. Finally we extend the theory to three dimensions and discuss the limit of a weak spanwise dependence for uniform wavetrains, showing that two functions are required to describe the evolution. These unknowns are a phase and a pressure function which satisfy a pair of linearly coupled partial differential equations. The results obtained from applying the same analysis to the fully three dimensional problem are included as an appendix

Ames collaborative study of cosmic-ray neutrons. 2: Low- and mid-latitude flights

Progress of the study of cosmic ray neutrons is described. Data obtained aboard flights from Hawaii at altitudes of 41,000 and 45,000 feet, and in the range of geomagnetic latitude 17 N less than or equal to lambda less than or equal to 21 N are reported. Preliminary estimates of neutron spectra are made