Space and time from translation symmetry

We show that the notions of space and time in algebraic quantum field theory arise from translation symmetry if we assume asymptotic commutativity. We argue that this construction can be applied to string theory.Comment: 10 pages, Essential changes and additions, in particular, in the discussion of string field theor

Corpus-Based Transcription as an Approach to the Compositional Control of Timbre

Timbre space is a cognitive model useful to address the problem of structuring timbre in electronic music. The recent concept of corpus-based concatenative sound synthesis is proposed as an approach to timbral control in both real- and deferred-time applications. Using CataRT and related tools in the FTM and Gabor libraries for Max/MSP we describe a technique for real-time analysis of a live signal to pilot corpus-based synthesis, along with examples of compositional realizations in works for instruments, electronics, and sound installation. To extend this technique to computer-assisted composition for acoustic instruments, we develop tools using the Sound Description Interchange Format (SDIF) to export sonic descriptors to OpenMusic where they may be further manipulated and transcribed into an instrumental score. This presents a flexible technique for the compositional organization of noise-based instrumental sounds

Wavelet Features for Recognition of First Episode of Schizophrenia from MRI Brain Images

Machine learning methods are increasingly used in various fields of medicine, contributing to early diagnosis and better quality of care. These outputs are particularly desirable in case of neuropsychiatric disorders, such as schizophrenia, due to the inherent potential for creating a new gold standard in the diagnosis and differentiation of particular disorders. This paper presents a scheme for automated classification from magnetic resonance images based on multiresolution representation in the wavelet domain. Implementation of the proposed algorithm, utilizing support vector machines classifier, is introduced and tested on a dataset containing 104 patients with first episode schizophrenia and healthy volunteers. Optimal parameters of different phases of the algorithm are sought and the quality of classification is estimated by robust cross validation techniques. Values of accuracy, sensitivity and specificity over 71% are achieved

Vascular challenges from pancreatoduodenectomy in the setting of coeliac artery stenosis

Coeliac artery stenosis due to median arcuate ligament compression or atherosclerotic disease is a frequently unrecognised challenge to recovery after pancreatoduodenectomy. The described case illustrates management with intraoperative superior mesenteric artery to hepatic artery bypass graft that led to haemorrhagic challenges postoperatively but ultimately a good recovery. Aspects of preoperative diagnosis, preoperative intervention and intraoperative management options are reviewed. Surgeons need to possess these tools to prevent complications from coeliac artery stenosis when pancreatoduodenectomy is required

Towards integrated island management: lessons from Lau, Malaita, for the implementation of a national approach to resource management in Solomon Islands: final report

Solomon Islands has recently developed substantial policy aiming to support inshore fisheries management, conservation, climate change adaptation and ecosystem approaches to resource management. A large body of experience in community based approaches to management has developed but “upscaling” and particularly the implementation of nation-wide approaches has received little attention so far. With the emerging challenges posed by climate change and the need for ecosystem wide and integrated approaches attracting serious donor attention, a national debate on the most effective approaches to implementation is urgently needed. This report discusses potential implementation of “a cost-effective and integrated approach to resource management that is consistent with national policy and needs” based on a review of current policy and institutional structures and examination of a recent case study from Lau, Malaita using stakeholder, transaction and financial cost analyses

Potential contributions of noncontact atomic force microscopy for the future Casimir force measurements

Surface electric noise, i.e., the non-uniform distribution of charges and potentials on a surface, poses a great experimental challenge in modern precision force measurements. Such a challenge is encountered in a number of different experimental circumstances. The scientists employing atomic force microscopy (AFM) have long focused their efforts to understand the surface-related noise issues via variants of AFM techniques, such as Kelvin probe force microscopy or electric force microscopy. Recently, the physicists investigating quantum vacuum fluctuation phenomena between two closely-spaced objects have also begun to collect experimental evidence indicating a presence of surface effects neglected in their previous analyses. It now appears that the two seemingly disparate science communities are encountering effects rooted in the same surface phenomena. In this report, we suggest specific experimental tasks to be performed in the near future that are crucial not only for fostering needed collaborations between the two communities, but also for providing valuable data on the surface effects in order to draw the most realistic conclusion about the actual contribution of the Casimir force (or van der Waals force) between a pair of real materials.Comment: The paper appeared in the Proceedings to the 12th International Conference on Noncontact Atomic Force Microscopy (NC-AFM 2009) and Casimir 2009 Satellite Worksho

Traction force microscopy on soft elastic substrates: a guide to recent computational advances

The measurement of cellular traction forces on soft elastic substrates has become a standard tool for many labs working on mechanobiology. Here we review the basic principles and different variants of this approach. In general, the extraction of the substrate displacement field from image data and the reconstruction procedure for the forces are closely linked to each other and limited by the presence of experimental noise. We discuss different strategies to reconstruct cellular forces as they follow from the foundations of elasticity theory, including two- versus three-dimensional, inverse versus direct and linear versus non-linear approaches. We also discuss how biophysical models can improve force reconstruction and comment on practical issues like substrate preparation, image processing and the availability of software for traction force microscopy.Comment: Revtex, 29 pages, 3 PDF figures, 2 tables. BBA - Molecular Cell Research, online since 27 May 2015, special issue on mechanobiolog