A toolbox for animal call recognition

Monitoring the natural environment is increasingly important as habit degradation and climate change reduce theworld’s biodiversity.We have developed software tools and applications to assist ecologists with the collection and analysis of acoustic data at large spatial and temporal scales.One of our key objectives is automated animal call recognition, and our approach has three novel attributes. First, we work with raw environmental audio, contaminated by noise and artefacts and containing calls that vary greatly in volume depending on the animal’s proximity to the microphone. Second, initial experimentation suggested that no single recognizer could dealwith the enormous variety of calls. Therefore, we developed a toolbox of generic recognizers to extract invariant features for each call type. Third, many species are cryptic and offer little data with which to train a recognizer. Many popular machine learning methods require large volumes of training and validation data and considerable time and expertise to prepare. Consequently we adopt bootstrap techniques that can be initiated with little data and refined subsequently. In this paper, we describe our recognition tools and present results for real ecological problems

Cloud-based Medical Image Collection Database with Automated Annotation

Typical medical image annotation systems use manual annotation or complex proprietary software such as computer-assisted-diagnosis. A more objective approach is required to achieve generalised Content Based Image Retrieval (CBIR) functionality. The Automated Medical Image Collection Annotation (AMICA) toolkit described here addresses this need. A range of content analysis functions are provided to tag images and image regions. The user uploads a DICOM file to an online portal and the software finds and displays images that have similar characteristics. AMICA has been developed to run in the Microsoft cloud environment using the Windows Azure platform, to cater for the storage requirements of typical large medical image databases

Existence and uniqueness of best approximants, with numerical applications

Part I of the thesis deals with existence and uniqueness theorems. Strengthening a result due to J. Blatter, it is proved in chapter 3 that a normed linear space is complete if every closed, bounded, and convex set is proximinal. It is also shown, that in a semi-reflexive, locally convex, real linear metric space, every closed, bounded and convex set is proximinal. An example is constructed which proves that not every reflexive space is sequentially convex. In chapter 4, sequential and local uniform convexity are shown to be independent properties. It is proved that a sequentially convex space can be equivalently renormed with a locally uniformly convex norm. Various spaces are shown to be incapable of uniformly convex renorming. In chapter 5, a number of convexity properties and a class of convergence processes are generalized to metric spaces. It is shown that Clarkson's renorming technique can be extended to metrics and that each closed subset of a metric space can be made proximinal by introducing an equivalent metric. Chapter 6 provides a link between the abstract material of previous chapters and the numerical applications of part II. A unified theory is developed which comprises both discrete and continuous Chebyshev approximation. Part II of the thesis contains numerical applications to the approximation of functions, data analysis, mathematical modelling, and optimization. Chapter 7 deals with a modified exchange algorithm for Chebyshev approximation. In chapter 8, closed formulae for linear Chebyshev approximants are derived. A computer approximation is obtained which is subject to restrictions on the number of non-zero bits in its binary representation. In chapter 9, an algorithm is developed which determines the L^ solution set and selects a strictly best solution. Chapter 10 deals with the problem of balancing the input and output streams of mineral processing plants. A comparison is made of various existing methods and some new algorithms are suggested. In chapter 11, an integer programming algorithm is developed which allows the user to search for sub-optimal and alternative optimal solutions. Codings of the algorithms in chapters 7, 9, 10, and 11 are listed in the appendix of programs. A separate pocket at the end of the thesis contains two papers published in advance

Myosin Va’s adaptor protein melanophilin enforces track selection on the microtubule and actin networks in vitro

Significance Inner organization of eukaryotic cells intimately depends on the active transport of diverse intracellular cargo on the ubiquitous actin and microtubule networks. The underlying mechanisms of such directional transport processes have been of outstanding interest. We studied a motor complex composed of Rab27a, melanophilin, and myosin Va and found, surprisingly, that the adaptor protein melanophilin toggled the binding preference toward actin or microtubules in vitro. Our results offer unexpected mechanistic insights into biasing the directionality of a moving organelle on the cytoskeleton through phospho-targeting the adaptor protein rather than its motor in vivo.</jats:p

DNA topoisomerase II selects DNA cleavage sites based on reactivity rather than binding affinity

DNA topoisomerase II modulates DNA topology by relieving supercoil stress and by unknotting or decatenating entangled DNA. During its reaction cycle, the enzyme creates a transient double-strand break in one DNA segment, the G-DNA. This break serves as a gate through which another DNA segment is transported. Defined topoisomerase II cleavage sites in genomic and plasmid DNA have been previously mapped. To dissect the G-DNA recognition mechanism, we studied the affinity and reactivity of a series of DNA duplexes of varied sequence under conditions that only allow G-DNA to bind. These DNA duplexes could be cleaved to varying extents ranging from undetectable (<0.5%) to 80%. The sequence that defines a cleavage site resides within the central 20 bp of the duplex. The DNA affinity does not correlate with the ability of the enzyme to cleave DNA, suggesting that the binding step does not contribute significantly to the selection mechanism. Kinetic experiments show that the selectivity interactions are formed before rather than subsequent to cleavage. Presumably the binding energy of the cognate interactions is used to promote a conformational change that brings the enzyme into a cleavage competent state. The ability to modulate the extent of DNA cleavage by varying the DNA sequence may be valuable for future structural and mechanistic studies that aim to determine topoisomerase structures with DNA bound in pre- and post-cleavage states and to understand the conformational changes associated with DNA binding and cleavage

Visual threads: the benefits of multithreading in visual programming languages

technical reportAfter working with the CWave visual programming language, we discovered that many of our target domains required the ability to define parallel computations within a program. CWave has a strongly hierarchical model of computation, so it seemed like adding the ability to take a part of the hierarchy and execute it in parallel would provide a good way of solving the problem. This led us to the concept of the Visual Thread and its associated components. Effectively, the Visual Thread allows the programmer to specify a part of the hierarchy and execute that part in parallel with the rest of program. We have used this implementation in several domains and demonstrated that it allows easy mapping of real world problems into our language. It eliminates most of the complexities often associated with programming parallel applications. We have also used a first prototype of our code generation system to translate CWave into Promela which allows us to verify correctness properties of the programs

Merchant Guilds, Taxation and Social Capital

We develop a theory of the emergence of merchant guilds as an efficient mechanism to foster cooperation between merchants and rulers, building on the complementarity between merchant guilds’ ability to enforce monopoly over trade and their social capital. Unlike existing models, we focus on local merchant guilds, rather than alien guilds, accounting for the main observed features of their behavior, internal organization and relationship with rulers. Our model delivers novel predictions about the emergence, variation, functioning, and eventual decline of this highly successful historical form of network. Our theory reconciles previous explanations and the large body of historical evidence on medieval merchant guilds. In doing so, we also shed novel light on the role of the guilds’ social capital, and its importance for taxation, welfare, and the development of towns and their government in medieval Europe

Cities in late medieval Europe: the promise and curse of modernity

This article examines how modern historiography has developed quite differentiated views on the way medieval cities have given expression to renewal and to creativity. 'National' traditions have played a highly influential role in modifying the general views articulated in the major syntheses produced by scholars such as Max Weber and Henri Pirenne at the beginning of the twentieth century. An almost jubilant way of looking at the city as the hotbed of modernity gave room, in the decades after the Great War, to pessimism and a negative view on urbanity, before a more nuanced and positive view has been re-established after World War II and in the course of recent paradigmatic changes

The biogenesis and function of nucleosome arrays

Numerous chromatin remodeling enzymes position nucleosomes in eukaryotic cells. Aside from these factors, transcription, DNA sequence, and statistical positioning of nucleosomes also shape the nucleosome landscape. The precise contributions of these processes remain unclear due to their functional redundancy in vivo. By incisive genome engineering, we radically decreased their redundancy in Saccharomyces cerevisiae. The transcriptional machinery strongly disrupts evenly spaced nucleosomes. Proper nucleosome density and DNA sequence are critical for their biogenesis. The INO80 remodeling complex helps space nucleosomes in vivo and positions the first nucleosome over genes in an H2A.Z-independent fashion. INO80 requires its Arp8 subunit but unexpectedly not the Nhp10 module for spacing. Cells with irregularly spaced nucleosomes suffer from genotoxic stress including DNA damage, recombination and transpositions. We derive a model of the biogenesis of the nucleosome landscape and suggest that it evolved not only to regulate but also to protect the genome

NATO und NATO-Osterweiterung: Pro und contra in Beiträgen

Kontroverse Debatte zur Ost-Erweiterung der NATO in der Mitte der 1990er Jahren.:- Erich Hocke: Osterweiterung der NATO - Weg zu einem europäischen Sicherheitssystem? - Dietrich von der Planitz: Die neue NATO. - Entwicklung der Allianz seit 1990. Tendenzen für die nahe Zukunft. - Ernst Woit: Osterweiterung der NATO. Interessen, Ziele, Konsequenzen. - Erich Hocke: Modell Matrjoschka-Puppe. Eine Nachbetrachtung zur Berliner NATO-Tagung. (Aus Wochenzeitung 'Freitag'