Some Computational Aspects of Essential Properties of Evolution and Life

While evolution has inspired algorithmic methods of heuristic optimisation, little has been done in the way of using concepts of computation to advance our understanding of salient aspects of biological evolution. We argue that under reasonable assumptions, interesting conclusions can be drawn that are of relevance to behavioural evolution. We will focus on two important features of life--robustness and fitness optimisation--which, we will argue, are related to algorithmic probability and to the thermodynamics of computation, subjects that may be capable of explaining and modelling key features of living organisms, and which can be used in understanding and formulating algorithms of evolutionary computation

The distributional impact of KiwiSaver incentives

New Zealand’s approach to retirement incomes profoundly changed with the recent introduction of KiwiSaver and its associated tax incentives. Previous policy reduced lifetime inequality but KiwiSaver and its tax incentives will increase future inequality and lead to diverging living standards for the elderly. In this paper we evaluate the distributional effects of these tax incentives. Using data from a nationwide survey conducted by the authors, we estimate the value of the equivalent income transfer provided to individuals by the tax incentives for KiwiSaver participation. Concentration curves and inequality decompositions are used to compare the distributive impact of these tax incentives with those for New Zealand Superannuation. Estimates are reported for both initial and lifetime impacts, with the greatest effect on inequality apparent in the lifetime impacts

Approximations of Algorithmic and Structural Complexity Validate Cognitive-behavioural Experimental Results

We apply methods for estimating the algorithmic complexity of sequences to behavioural sequences of three landmark studies of animal behavior each of increasing sophistication, including foraging communication by ants, flight patterns of fruit flies, and tactical deception and competition strategies in rodents. In each case, we demonstrate that approximations of Logical Depth and Kolmogorv-Chaitin complexity capture and validate previously reported results, in contrast to other measures such as Shannon Entropy, compression or ad hoc. Our method is practically useful when dealing with short sequences, such as those often encountered in cognitive-behavioural research. Our analysis supports and reveals non-random behavior (LD and K complexity) in flies even in the absence of external stimuli, and confirms the "stochastic" behaviour of transgenic rats when faced that they cannot defeat by counter prediction. The method constitutes a formal approach for testing hypotheses about the mechanisms underlying animal behaviour.Comment: 28 pages, 7 figures and 2 table

Indices of health and sickness in university students : a study based on the work of the Student Health Service, St. Andrews University (in Dundee) during the years 1948-1952

When in October, 1948, the University of St. Andrews inaugurated a Student Health Service, I was one of the two Medical Officers appointed. My duties lie in that part of the University situated in Dundee. Since then it has been my practice to submit to the University authorities an annual report of the work and activities of my side of the Student Health Service during the preceding academic year. The idea occurred to me, I think, while working on the report for the year 1950 -51, that albeit in a very small and modest way, these annual reports were possibly contributing a little to the sum of knowledge in the social aspects of medicine.Over each period of one year a small group of people had been studied in health and in sickness. Certain findings at medical examination during health or at medical attendance in illness had been recorded. If no unjustifiable conclusions were attempted, the facts recorded might at least be of interest if not of value. At some later date was born the idea that in the facts recorded there might be the material for a thesis in the subject of Social Medicine. Since then a good deal of my spare time has been devoted to the preparation of the thesis now presented.At an early stage it was appreciated that my own annual reports dealt with too few students and were themselves too limited in scope to give a sufficiently representative picture of all that is now implied in the term "student health" and that only by drawing on the much wider experience in universities elsewhere could my own material be set in correct perspective.The aim then became a thesis covering the whole field of student health study in this country, reviewing the work done in the subject to date and comparing my own findings and standards with those obtained by my colleagues in other universities in Britain and in Northern Ireland. Even that aim had to be modified when it was found that several volumes would be required to deal adequately with every aspect of the subject.In its final form the thesis became an attempt to consider in some detail certain of the main features of the work of university health services in this country, to review the standards of health and sickness that are now emerging, and to evaluate my own findings in this small university in the light of these standards. It is fully appreciated that a subject such as "Tuberculosis in Students" dealt with in one section here, has in it the material for an entire thesis to itself. The restriction was imposed here in order to preserve something of the original intention which which was to give a general review of student health work.The thesis is presented in two parts. In the first, some of the main features of student health work are discussed and my own findings set against those obtained by colleagues working in other universities. Certain opinions expressed are my own and would not necessarily be endorsed by the Student Health Committee or by the Court of this university.The second part consists of the actual annual reports I have submitted to the University Court during the four years I have worked as one of their Medical Officers. These reports, although containing certain personal views which on some points have varied or undergone modification as experience was acquired, present the factual data on which were based the various comparisons and conclusions set down in the first part of the thesis. For that reason if for no other, it was felt desirable to include these reports as an integral part of the thesis. Attention is directed particularly to the report for the year 1951-52 which on some points summarises the experience of four years' work in this university.I trust that in the title of the thesis, the use of the word "indices" is not misleading. In conditions like clinical, pulmonary tuberculosis, it is probably true to state that there is now an accepted figure which represents with some accuracy the expected incidence/ incidence in university students. But more frequently I have used figures for their descriptive value only and no precise statistical significance is claimed for them

Wage Structures and Employment Outcomes in New Zealand, and Their Relationship to Technological Change

After 100 years at an historically low level, inequality began to rise in the late 20th century, a trend which was especially marked in the English-speaking countries including New Zealand. Various explanations have been advanced, but internationally the most favoured theory is skill-biased technological change, driven by the new information and communication technologies. This thesis used income and wage data from the New Zealand Population Census and the New Zealand Income Survey to examine wage trends between 1991 and 2004. As in other developed countries wage dispersion was increasing in the 1990s, though it appears to have slowed since 2001, and the increased inequality is strongly correlated with workers' skills and qualifications. There is also a correlation between new technology and earnings inequality, but this appears to be attributable to the demand for skills in the industries which are changing fastest, rather than anything intrinsic to the new technology

Regulating star formation in a magnetized disk galaxy

We use high-resolution MHD simulations of isolated disk galaxies to investigate the co-evolution of magnetic fields with a self-regulated, star-forming interstellar medium (ISM). The simulations are conducted using the Ramses AMR code on the standard Agora initial condition, with gas cooling, star formation and feedback. We run galaxies with a variety of initial magnetic field strengths. The fields grow rapidly and achieve approximate saturation within 500 Myr, but at different levels. The galaxies reach a quasi-steady state, with slowly declining star formation due to both gas consumption and increases in the field strength at intermediate ISM densities. We connect this behaviour to differences in the gas properties and overall structure of the galaxies. In particular, strong fields limit feedback bubbles. Different cases support the ISM using varying combinations of magnetic pressure, turbulence and thermal energy. Magnetic support is closely linked to stellar feedback in the case of initially weak fields but not for initially strong fields. The spatial distribution of these supports is also different in each case, and this is reflected in the stability of the gas disk. We relate this back to the overall distribution of star formation in each case. We conclude that a weak initial field can grow to produce a realistic model of a local disk galaxy, but starting with typical field strengths will not.Comment: 12 pages, 11 figures. Submitted to MNRA

Morphology with Light Profile Fitting of Confirmed Cluster Galaxies at z=0.84

We perform a morphological study of 124 spectroscopically confirmed cluster galaxies in the z=0.84 galaxy cluster RX J0152.7-1357. Our classification scheme includes color information, visual morphology, and 1-component and 2-component light profile fitting derived from Hubble Space Telescope riz imaging. We adopt a modified version of a detailed classification scheme previously used in studies of field galaxies and found to be correlated with kinematic features of those galaxies. We compare our cluster galaxy morphologies to those of field galaxies at similar redshift. We also compare galaxy morphologies in regions of the cluster with different dark-matter density as determined by weak-lensing maps. We find an early-type fraction for the cluster population as a whole of 47%, about 2.8 times higher than the field, and similar to the dynamically young cluster MS 1054 at similar redshift. We find the most drastic change in morphology distribution between the low and intermediate dark matter density regions within the cluster, with the early type fraction doubling and the peculiar fraction dropping by nearly half. The peculiar fraction drops more drastically than the spiral fraction going from the outskirts to the intermediate-density regions. This suggests that many galaxies falling into clusters at z~0.8 may evolve directly from peculiar, merging, and compact systems into early-type galaxies, without having the chance to first evolve into a regular spiral galaxy.Comment: 13 pages, 11 figures, accepted for publication in A&

Multichannel demultiplexer/demodulator technologies for future satellite communication systems

NASA-Lewis' Space Electronics Div. supports ongoing research in advanced satellite communication architectures, onboard processing, and technology development. Recent studies indicate that meshed VSAT (very small aperture terminal) satellite communication networks using FDMA (frequency division multiple access) uplinks and TDMA (time division multiplexed) downlinks are required to meet future communication needs. One of the critical advancements in such a satellite communication network is the multichannel demultiplexer/demodulator (MCDD). The progress is described which was made in MCDD development using either acousto-optical, optical, or digital technologies