47 research outputs found

    Automated Extraction and Classification of Time-Frequency Contours in Humpback Vocalizations

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    A time-frequency contour extraction and classification algorithm was created to analyze humpback whale vocalizations. The algorithm automatically extracted contours of whale vocalization units by searching for gray-level discontinuities in the spectrogram images. The unit-to-unit similarity was quantified by cross-correlating the contour lines. A library of distinctive humpback units was then generated by applying an unsupervised, cluster-based learning algorithm. The purpose of this study was to provide a fast and automated feature selection tool to describe the vocal signatures of animal groups. This approach could benefit a variety of applications such as species description, identification, and evolution of song structures. The algorithm was tested on humpback whale song data recorded at various locations in Hawaii from 2002 to 2003. Results presented in this paper showed low probability of false alarm (0%–4%) under noisy environments with small boat vessels and snapping shrimp. The classification algorithm was tested on a controlled set of 30 units forming six unit types, and all the units were correctly classified. In a case study on humpback data collected in the Auau Chanel, Hawaii, in 2002, the algorithm extracted 951 units, which were classified into 12 distinctive types

    Magnetic resonance spectroscopy in adult-onset citrullinemia: Elevated glutamine levels in comatose patients

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    10.1001/archneur.64.7.1034Archives of Neurology6471034-1037ARNE

    Cognitive deficits in mild Parkinson's disease are associated with distinct areas of grey matter atrophy

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    10.1136/jnnp-2013-305805Journal of Neurology, Neurosurgery and Psychiatry855576-580JNNP

    Cognitive decline in early Parkinson's disease

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    10.1002/mds.22384Movement Disorders244605-608MOVD

    Cerebral white matter hyperintensity in Parkinson's disease: A major risk factor for mild cognitive impairment

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    10.1016/j.parkreldis.2013.03.008Parkinsonism and Related Disorders197680-683PRDI
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