The LOST Algorithm: finding lines and separating speech mixtures

Robust clustering of data into linear subspaces is a frequently encountered problem. Here, we treat clustering of one-dimensional subspaces that cross the origin. This problem arises in blind source separation, where the subspaces correspond directly to columns of a mixing matrix. We propose the LOST algorithm, which identifies such subspaces using a procedure similar in spirit to EM. This line finding procedure combined with a transformation into a sparse domain and an L1-norm minimisation constitutes a blind source separation algorithm for the separation of instantaneous mixtures with an arbitrary number of mixtures and sources. We perform an extensive investigation on the general separation performance of the LOST algorithm using randomly generated mixtures, and empirically estimate the performance of the algorithm in the presence of noise. Furthermore, we implement a simple scheme whereby the number of sources present in the mixtures can be detected automaticall

Discovering speech phones using convolutive non-negative matrix factorisation with a sparseness constraint

Discovering a representation that allows auditory data to be parsimoniously represented is useful for many machine learning and signal processing tasks. Such a representation can be constructed by Non-negative Matrix Factorisation (NMF), a method for finding parts-based representations of non-negative data. Here, we present an extension to convolutive NMF that includes a sparseness constraint, where the resultant algorithm has multiplicative updates and utilises the beta divergence as its reconstruction objective. In combination with a spectral magnitude transform of speech, this method discovers auditory objects that resemble speech phones along with their associated sparse activation patterns. We use these in a supervised separation scheme for monophonic mixtures, finding improved separation performance in comparison to classic convolutive NMF

Identification of misconceptions in the teaching of biology

peer-reviewedTo date research into how young people acquire accurate higher-order scientific knowledge, and gain an understanding of abstract and challenging concepts in science, has occupied much of the science education literature across countries and across continents. In previous studies, we identified that biology teaching that involves the diagnosis, reduction and elimination of misconceptions can be one effective pedagogic approach, particularly if positioned within a “good enough” model of pedagogic practice1 . In this study, we investigate the use of one diagnostic testing approach to the identification of misconceptions in the teaching of respiration and photosynthesis in a small sample of secondary school students (n=139) and pre-service teachers (n=43) in the Republic of Ireland. Photosynthesis and respiration were chosen as they are prevalent biology topics that students find conceptually challenging. The study used test items to elicit the extent of misconceptions among this cohort – a paper-and-pencil test for students and a survey instrument for pre-service teachers. The findings show unacceptably high level of misconceptions among all pre-service teachers and students and suggest that diagnostic tests of this type can be a useful entry point to a pedagogical cycle for the recognition, reduction and removal of misconceptions. The findings have wider implications than this small scale study and are primarily directed toward new understandings in relation to more effective models of biology teaching and teacher education.PUBLISHEDpeer-reviewe

The origin of centennial- to millennial-scale chronological gaps in storm emplaced beach ridge plains

Recent studies of tropical cyclone surge and wave emplaced beach ridge plains have shown that these sequences often contain centennial to millennial scale gaps in their chronologies. Two explanations for the gaps exist — they are due to erosion, or alternatively a cessation or substantial slowing of depositional processes suggestive of a quieter phase in intense storm activity. Differentiating between the two is important for uncovering reliable long-term storm histories from these sequences. We use landform morphology, sediment texture and luminescence chronology to determine the origin of substantial chronological gaps in a plain containing more than 100 shore-parallel ridges composed of fine-grained sand located in northeast Australia. We identify and describe the characteristics associated with both erosional and non-erosional gaps. The erosional gaps are associated with changes in orientation between ridge sets and often a high ridge with hummocky topography that appears to have been disturbed by aeolian activity. River floods likely caused the partial erosion of ridge sets. Non-erosional gaps do not display these morphological characteristics and are likely associated with quiescence in severe tropical cyclone activity. These geomorphic and chronological signatures can be used to identify different sorts of gaps in other ridge plains and are an important tool in the reconstruction of long-term storm histories from these coastal landforms. The data also suggests that fine-grained ridges can, like their coarse-grained counterparts, be predominantly deposited by storm waves and surge and their texture need not necessarily be indicative of the processes responsible for ridge development

New skeletal tuberculosis cases in past populations from Western Hungary (Transdanubia)

The distribution, antiquity and epidemiology of tuberculosis (TB) have previously been studied in osteoarchaeological material in the eastern part of Hungary, mainly on the Great Plain. The purpose of this study is to map the occurrence of skeletal TB in different centuries in the western part of Hungary, Transdanubia, and to present new cases we have found. Palaeopathological analysis was carried out using macroscopic observation supported by radiographic and molecular methods. A large human osteoarchaeological sample (n = 5684) from Transdanubian archaeological sites ranging from the 2nd to the 18th centuries served as a source of material. Spinal TB was observed in seven individuals (in three specimens with Pott's disease two of which also had cold abscess) and hip TB was assumed in one case. The results of DNA for Mycobacterium tuberculosis were positive in seven of the eight cases identified by paleopathology, and negative in the assumed case of hip TB. However, the molecular results are consistent with highly fragmented DNA, which limited further analysis. Based on the present study and previously published cases, osteotuberculosis was found in Transdanubia mainly during the 9th–13th centuries. However, there are no signs of TB in many other 9th–13th century sites, even in those that lie geographically close to those where osteotuberculous cases were found. This may be due to a true absence of TB caused by the different living conditions, way of life, or origin of these populations. An alternative explanation is that TB was present in some individuals with no typical paleopathology, but that death occurred before skeletal morphological features could develop

Exploring the contribution of music intervention programmes for children in challenging circumstances: a collaborative research project between soundLINCS and Nottingham Trent University

APPEAL FROM ORDER OF DISMISSAL AND ORDER AWARDING ATTORNEY FEES, A DENIAL OF A MOTION TO(SET ASIDE, AND A DENIAL OF A MOTION FOR A NEW TRIAL OR TO ALTER OR AMEND THE JUDGMENT IN THE THIRD JUDICIAL DISTRICT COURT IN AND FOR SALT LAKE COUNTY, THE HONORABLE STEPHEN L.HENRIOD, PRESIDIN