Gravitational Radiation from Post-Newtonian Sources and Inspiralling Compact Binaries

The article reviews the current status of a theoretical approach to the problem of the emission of gravitational waves by isolated systems in the context of general relativity. Part A of the article deals with general post-Newtonian sources. The exterior field of the source is investigated by means of a combination of analytic post-Minkowskian and multipolar approximations. The physical observables in the far-zone of the source are described by a specific set of radiative multipole moments. By matching the exterior solution to the metric of the post-Newtonian source in the near-zone we obtain the explicit expressions of the source multipole moments. The relationships between the radiative and source moments involve many non-linear multipole interactions, among them those associated with the tails (and tails-of-tails) of gravitational waves. Part B of the article is devoted to the application to compact binary systems. We present the equations of binary motion, and the associated Lagrangian and Hamiltonian, at the third post-Newtonian (3PN) order beyond the Newtonian acceleration. The gravitational-wave energy flux, taking consistently into account the relativistic corrections in the binary moments as well as the various tail effects, is derived through 3.5PN order with respect to the quadrupole formalism. The binary's orbital phase, whose prior knowledge is crucial for searching and analyzing the signals from inspiralling compact binaries, is deduced from an energy balance argument.Comment: 109 pages, 1 figure; this version is an update of the Living Review article originally published in 2002; available on-line at http://www.livingreviews.org

Protective Human Leucocyte Antigen Haplotype, HLA-DRB1*01-B*14, against Chronic Chagas Disease in Bolivia

Chronic Chagas disease consists of four different forms categorized on the basis of their clinical manifestations, namely; cardiac, digestive, cardiodigestive and indeterminate. In Latin America, there are 8–10 million seropositive persons who are at risk of, or have already developed serious clinical complications and who have limited access to effective treatment. The cardiac and digestive forms are characterized by tissue damage caused by persistent infection of Trypanosoma cruzi and are thought to be modulated by host immunity. In our large scale screening for chronic Chagas disease in Santa Cruz, Bolivia, hearts and colons of 229 seropositive patients were examined. We found 31.4% of patients had abnormal electrocardiograms (ECGs), 15.7% presented with megacolon, 5.2% had a combination of abnormal ECG and megacolon, and 58.1% were of indeterminate status. Previously, we attempted to ascertain whether parasite genetic polymorphism might account for the differences in clinical manefestations, by analyzing parasite DNA taken from the same study group (with the addition of a further 62 megacolon post-operational patients). We found no relationships between parasite lineages and clinical disease form. The present study reveals that host HLA polymorphisms associate with clinical manifestations of Chagas

Bostonia: v. 62, no. 2, 5-6

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Gravitational-wave research as an emerging field in the Max Planck Society. The long roots of GEO600 and of the Albert Einstein Institute

On the occasion of the 50th anniversary since the beginning of the search for gravitational waves at the Max Planck Society, and in coincidence with the 25th anniversary of the foundation of the Albert Einstein Institute, we explore the interplay between the renaissance of general relativity and the advent of relativistic astrophysics following the German early involvement in gravitational-wave research, to the point when gravitational-wave detection became established by the appearance of full-scale detectors and international collaborations. On the background of the spectacular astrophysical discoveries of the 1960s and the growing role of relativistic astrophysics, Ludwig Biermann and his collaborators at the Max Planck Institute for Astrophysics in Munich became deeply involved in research related to such new horizons. At the end of the 1960s, Joseph Weber's announcements claiming detection of gravitational waves sparked the decisive entry of this group into the field, in parallel with the appointment of the renowned relativist Juergen Ehlers. The Munich area group of Max Planck institutes provided the fertile ground for acquiring a leading position in the 1970s, facilitating the experimental transition from resonant bars towards laser interferometry and its innovation at increasingly large scales, eventually moving to a dedicated site in Hannover in the early 1990s. The Hannover group emphasized perfecting experimental systems at pilot scales, and never developed a full-sized detector, rather joining the LIGO Scientific Collaboration at the end of the century. In parallel, the Max Planck Institute for Gravitational Physics (Albert Einstein Institute) had been founded in Potsdam, and both sites, in Hannover and Potsdam, became a unified entity in the early 2000s and were central contributors to the first detection of gravitational waves in 2015.Comment: 94 pages. Enlarged version including new results from further archival research. A previous version appears as a chapter in the volume The Renaissance of General Relativity in Context, edited by A. Blum, R. Lalli and J. Renn (Boston: Birkhauser, 2020

The application of constraint logic programming to cane railway scheduling

In Australia, cane transport is the largest unit cost in the manufacturing of raw sugar, making up around 35% of the total manufacturing costs. Producing efficient schedules for the cane railways can result in significant cost savings. This thesis presents a study of using Constraint Logic Programming (CLP) for solving the cane transport scheduling problem. CLP is an extension of logic programming languages that incorporates constraints and constraint solving methods. The cane railway scheduling problem (CRSP) is a unique problem. Although it shares some characteristics with many well-studied operations research problems it has many properties that made expressing it in a form suitable for CLP a novel challenge. Modern metaheuristic methods such as genetic algorithms and tabu search have been successfully applied to combinatorial optimisation problems including the CRSP. These metaheuristics use a variety of means to sample a subset of the total available solution set. In contrast, CLP relies on forward-checking to reduce the size of the solution set. Forward-checking results in the rejection of infeasible solutions as early as possible in the search. However for the CRSP, forward-checking alone proved to be insufficient to prune the search tree adequately. The novel heuristic labelling approach presented in this thesis proposes the concept of labelling templates to ensure that a good quality subset of possible solutions is tested. This heuristic labelling technique is tailored to the CLP approach and to the CRSP. However the approach should be applicable to other CLP applications. Encouraging results of the application to several test problems and one real-life case are presented. The results demonstrate that CLP can be used as an effective tool for solving the cane transport scheduling problem. It can also be used as an efficient tool for altering an existing schedule to accommodate real-time changes in the cane transport system. The current integrated cane transport scheduling system that has been developed to address the CRSP does not include a dedicated rescheduling component.</p

Creating a supportive PBL environment in two engineering courses at Central Queensland University

Project Based Learning (PBL) is challenging existing conceptions of good teaching in engineering education. When developing and reviewing the first year Engineering Skills course and the second year Fluid Mechanics course at Central Queensland University strategies were implemented to improve student engagement in the learning process. The learning outcomes for both the courses include many of the professional skills that are now recognized as being essential in the engineering workplace. These skills are introduced in the context of engineering projects rather than in separate ‘add-on’ modules. Self-directed learning and reflection which are fundamental aspects of PBL assist the development of important lifelong learning skills. The learning outcomes are aimed at building upon the various experiences which students bring with them. By promoting social and academic engagement within the project teams and between students and staff, the PBL paradigm facilitates the development of a learning community and therefore further improves the quality of the learning. The development of a learning community has been shown to be an important predictor of the development of student learning outcomes both in generic attributes such as communication, problem solving and ethical awareness as well as discipline-specific skills.PBL encourages student initiative, independence, collaboration and responsibility for learning through project work resulting in a productive pedagogy in the Engineering Skills and Fluid Mechanics courses. This paper will discuss the strategies employed in these two courses and how student learning is enhanced when the student participates responsibly in the learning process

Multi-campus partnerships and interactions in PBL courses

Central Queensland University (CQU) is a young multi-campus regional university based in Rockhampton, Central Queensland, Australia. The engineering undergraduate program consists of a combination of Project-based Learning, cooperative education and professional practice. The first two years of the engineering undergraduate program at CQU can be studied at any one of three campuses; Rockhampton, Gladstone or Mackay. Gladstone and Mackay campuses are separated by one hour and three hours travel by road respectively from the Rockhampton campus. During their first two years of study, students will have the opportunity to reside in their home city or region enabling a smoother transition from secondary to tertiary education. A significant component of the first year program is delivered using the Project Based Learning (PBL) paradigm, utilising a range of delivery modes including face-to-face workshops, synchronous video-conferencing of lectures, print-based materials, and web-based learning management. As a significant component of the PBL delivery, first year students undertake team projects which are supplied and supervised by industry personnel. In this paper, the authors examine the strategies and techniques associated with managing partnerships and interactions associated with first year PBL engineering courses, studied simultaneously at several campuses. Qualitative and Quantitative evidence supports that successful strategies for multi-campus management are being achieved to ensure equitable learning opportunities for all students