A Review of Measuring Ecosystem Resilience to Disturbance

Resilience is the central concept for understanding how an ecosystem responds to a strong perturbation, and is related to other concepts used to analyze system properties in the face of change such as resistance, recovery, sustainability, vulnerability, stability, adaptive capacity, regime shift, and tipping point. It is extremely challenging to formulate resilience thinking into practice. The current state-of-art approaches of assessing ecosystem resilience may be useful for policy makers and ecosystem resource managers to minimize climatological or natural disaster related impacts. Here, we review the methods of assessing resilience and classify and limit them to three cases: (1) forest resilience based mainly on remote sensing and tree-ring data; (2) soil microbial community resilience based on laboratory and field studies; and (3) hydrological resilience of terrestrial biomes based on the Budyko framework and climate data

The Role of Quorum Sensing in Bacterial Colony Dynamics

The quorum sensing (QS) signalling system allows colonies of bacteria to coordinate gene expression to optimise behaviour at low and high cell densities, giving rise to individual and group responses, respectively. The main aim of this thesis is to understand better the important roles of QS in bacterial colony dynamics. Thus a mathematical description was developed to thoroughly explore key mechanisms and parameter sensitivity. The nature of the QS system depends very much on the species. Pseudomonas aeruginosa was chosen as a model species for this study. P. aeruginosa is a Gram-negative bacterium that is responsible for a wide range of chronic infections in humans. Its QS signalling system is known to involve the las, rhl and pqs systems; this thesis focuses on the first two. The las system includes the LasR regulator and LasI synthase, which direct the synthesis of autoinducer 3O-C12-HSL. Similarly, the rhl system consists of the RhlR regulator and RhlI synthase, directing the synthesis of autoinducer C4-HSL. The mathematical model of the las system displays hysteresis phenomena and excitable dynamics. In essence, the system can have two stable steady states reflecting low and high signal molecule production, separated by one unstable steady state. This feature of the las system can give rise to excitable pulse generation with important downstream impact on the rhl system. The las system is coupled to the rhl system in two ways. First, LasR and 3O-C12-HSL activate the expression of their counterpart in the rhl system. Second, 3O-C12-HSL blocks activation of RhlR by C4-HSL. Furthermore, the las-rhl interaction provides a `quorum memory' that allows cells to trigger rhamnolipid production when they are at the edge of colony. It was demonstrated how the dynamical QS system in individual cells and with coupling between cells can affect the dynamics of the bacterial colony

A Scientific Metaphysical Naturalisation of Information: with a indication-based semantic theory of information and an informationist statement of physicalism.

The objective of this thesis is to present a naturalised metaphysics of information, or to naturalise information, by way of deploying a scientific metaphysics according to which contingency is privileged and a-priori conceptual analysis is excluded (or at least greatly diminished) in favour of contingent and defeasible metaphysics. The ontology of information is established according to the premises and mandate of the scientific metaphysics by inference to the best explanation, and in accordance with the idea that the primacy of physics constraint accommodates defeasibility of theorising in physics. This metametaphysical approach is used to establish a field ontology as a basis for an informational structural realism. This is in turn, in combination with information theory and specifically mathematical and algorithmic theories of information, becomes the foundation of what will be called a source ontology, according to which the world is the totality of information sources. Information sources are to be understood as causally induced configurations of structure that are, or else reduce to and/or supervene upon, bounded (including distributed and non-contiguous) regions of the heterogeneous quantum field (all quantum fields combined) and fluctuating vacuum, all in accordance with the above-mentioned quantum field-ontic informational structural realism (FOSIR.) Arguments are presented for realism, physicalism, and reductionism about information on the basis of the stated contingent scientific metaphysics. In terms of philosophical argumentation, realism about information is argued for primarily by way of an indispensability argument that defers to the practice of scientists and regards concepts of information as just as indispensable in their theories as contingent representations of structure. Physicalism and reductionism about information are adduced by way of the identity thesis that identifies the substance of the structure of ontic structural realism as identical to selections of structure existing in re to combined heterogeneous quantum fields, and to the total heterogeneous quantum field comprised of all such fields. Adjunctly, an informational statement of physicalism is arrived at, and a theory of semantic information is proposed, according to which information is intrinsically semantic and alethically neutral

Study of granular temperature in dense fluidized beds by diffusing wave spectroscopy

Diffusing wave spectroscopy (DWS), a non-intrusive multiple scattering technique, can be used to study the fundamentals of particle motion in dynamic dense granular media and measure the mean of the square of the particle velocity fluctuations about their mean, which is related directly to the so-called ‘granular temperature’ that underpins many theories for dynamic granular processes. An overview of DWS in the context of other techniques for studying the granular temperature and dynamics of particles in granular systems, and its application to a range of fluidized bed configurations is reported in this thesis. The thesis reports how the granular temperature and particle dynamics varies with the level of forcing for a liquid fluidized bed, and both dry and water-immersed vibro-fluidized beds. This data reveals that the granular temperature scales with, and is of the same order as, the forcing velocity (i.e. superficial velocity or peak vibrational velocity) for all except the water-immersed vibro-fluidized bed where it scales with the peak acceleration. The former appear to be in accord with theory, while no theory as yet has predicted the latter. The experimental data was also deconvoluted to reveal how the solid fraction affects the granular temperature in a liquid fluidized bed, which represents the most detailed experimental study in this regard. For the first time is revealed that vertical profiles of the granular temperature are a consequence of observed concentration stratification in a liquid fluidized bed. By way of example of the results that can be obtained using DWS, we have shown how it has provided a basis for us to hypothesise that particles in vibro-fluidized beds (both dry and water-immersed) rattle around in cages formed by their neighbours until their collective re-arrangement occurs at long time scales

Teaching and Learning of Fluid Mechanics

This book contains research on the pedagogical aspects of fluid mechanics and includes case studies, lesson plans, articles on historical aspects of fluid mechanics, and novel and interesting experiments and theoretical calculations that convey complex ideas in creative ways. The current volume showcases the teaching practices of fluid dynamicists from different disciplines, ranging from mathematics, physics, mechanical engineering, and environmental engineering to chemical engineering. The suitability of these articles ranges from early undergraduate to graduate level courses and can be read by faculty and students alike. We hope this collection will encourage cross-disciplinary pedagogical practices and give students a glimpse of the wide range of applications of fluid dynamics

The Fifteenth Marcel Grossmann Meeting

The three volumes of the proceedings of MG15 give a broad view of all aspects of gravitational physics and astrophysics, from mathematical issues to recent observations and experiments. The scientific program of the meeting included 40 morning plenary talks over 6 days, 5 evening popular talks and nearly 100 parallel sessions on 71 topics spread over 4 afternoons. These proceedings are a representative sample of the very many oral and poster presentations made at the meeting.Part A contains plenary and review articles and the contributions from some parallel sessions, while Parts B and C consist of those from the remaining parallel sessions. The contents range from the mathematical foundations of classical and quantum gravitational theories including recent developments in string theory, to precision tests of general relativity including progress towards the detection of gravitational waves, and from supernova cosmology to relativistic astrophysics, including topics such as gamma ray bursts, black hole physics both in our galaxy and in active galactic nuclei in other galaxies, and neutron star, pulsar and white dwarf astrophysics. Parallel sessions touch on dark matter, neutrinos, X-ray sources, astrophysical black holes, neutron stars, white dwarfs, binary systems, radiative transfer, accretion disks, quasars, gamma ray bursts, supernovas, alternative gravitational theories, perturbations of collapsed objects, analog models, black hole thermodynamics, numerical relativity, gravitational lensing, large scale structure, observational cosmology, early universe models and cosmic microwave background anisotropies, inhomogeneous cosmology, inflation, global structure, singularities, chaos, Einstein-Maxwell systems, wormholes, exact solutions of Einstein's equations, gravitational waves, gravitational wave detectors and data analysis, precision gravitational measurements, quantum gravity and loop quantum gravity, quantum cosmology, strings and branes, self-gravitating systems, gamma ray astronomy, cosmic rays and the history of general relativity

Book of abstracts of the 10th International Chemical and Biological Engineering Conference: CHEMPOR 2008

This book contains the extended abstracts presented at the 10th International Chemical and Biological Engineering Conference - CHEMPOR 2008, held in Braga, Portugal, over 3 days, from the 4th to the 6th of September, 2008. Previous editions took place in Lisboa (1975, 1889, 1998), Braga (1978), Póvoa de Varzim (1981), Coimbra (1985, 2005), Porto (1993), and Aveiro (2001). The conference was jointly organized by the University of Minho, “Ordem dos Engenheiros”, and the IBB - Institute for Biotechnology and Bioengineering with the usual support of the “Sociedade Portuguesa de Química” and, by the first time, of the “Sociedade Portuguesa de Biotecnologia”. Thirty years elapsed since CHEMPOR was held at the University of Minho, organized by T.R. Bott, D. Allen, A. Bridgwater, J.J.B. Romero, L.J.S. Soares and J.D.R.S. Pinheiro. We are fortunate to have Profs. Bott, Soares and Pinheiro in the Honor Committee of this 10th edition, under the high Patronage of his Excellency the President of the Portuguese Republic, Prof. Aníbal Cavaco Silva. The opening ceremony will confer Prof. Bott with a “Long Term Achievement” award acknowledging the important contribution Prof. Bott brought along more than 30 years to the development of the Chemical Engineering science, to the launch of CHEMPOR series and specially to the University of Minho. Prof. Bott’s inaugural lecture will address the importance of effective energy management in processing operations, particularly in the effectiveness of heat recovery and the associated reduction in greenhouse gas emission from combustion processes. The CHEMPOR series traditionally brings together both young and established researchers and end users to discuss recent developments in different areas of Chemical Engineering. The scope of this edition is broadening out by including the Biological Engineering research. One of the major core areas of the conference program is life quality, due to the importance that Chemical and Biological Engineering plays in this area. “Integration of Life Sciences & Engineering” and “Sustainable Process-Product Development through Green Chemistry” are two of the leading themes with papers addressing such important issues. This is complemented with additional leading themes including “Advancing the Chemical and Biological Engineering Fundamentals”, “Multi-Scale and/or Multi-Disciplinary Approach to Process-Product Innovation”, “Systematic Methods and Tools for Managing the Complexity”, and “Educating Chemical and Biological Engineers for Coming Challenges” which define the extended abstracts arrangements along this book. A total of 516 extended abstracts are included in the book, consisting of 7 invited lecturers, 15 keynote, 105 short oral presentations given in 5 parallel sessions, along with 6 slots for viewing 389 poster presentations. Full papers are jointly included in the companion Proceedings in CD-ROM. All papers have been reviewed and we are grateful to the members of scientific and organizing committees for their evaluations. It was an intensive task since 610 submitted abstracts from 45 countries were received. It has been an honor for us to contribute to setting up CHEMPOR 2008 during almost two years. We wish to thank the authors who have contributed to yield a high scientific standard to the program. We are thankful to the sponsors who have contributed decisively to this event. We also extend our gratefulness to all those who, through their dedicated efforts, have assisted us in this task. On behalf of the Scientific and Organizing Committees we wish you that together with an interesting reading, the scientific program and the social moments organized will be memorable for all.Fundação para a Ciência e a Tecnologia (FCT