500 research outputs found

    Parallel detrended fluctuation analysis for fast event detection on massive PMU data

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    ("(c) 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.")Phasor measurement units (PMUs) are being rapidly deployed in power grids due to their high sampling rates and synchronized measurements. The devices high data reporting rates present major computational challenges in the requirement to process potentially massive volumes of data, in addition to new issues surrounding data storage. Fast algorithms capable of processing massive volumes of data are now required in the field of power systems. This paper presents a novel parallel detrended fluctuation analysis (PDFA) approach for fast event detection on massive volumes of PMU data, taking advantage of a cluster computing platform. The PDFA algorithm is evaluated using data from installed PMUs on the transmission system of Great Britain from the aspects of speedup, scalability, and accuracy. The speedup of the PDFA in computation is initially analyzed through Amdahl's Law. A revision to the law is then proposed, suggesting enhancements to its capability to analyze the performance gain in computation when parallelizing data intensive applications in a cluster computing environment

    Parallel detrended fluctuation analysis for fast event detection on massive PMU data

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    ("(c) 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.")Phasor measurement units (PMUs) are being rapidly deployed in power grids due to their high sampling rates and synchronized measurements. The devices high data reporting rates present major computational challenges in the requirement to process potentially massive volumes of data, in addition to new issues surrounding data storage. Fast algorithms capable of processing massive volumes of data are now required in the field of power systems. This paper presents a novel parallel detrended fluctuation analysis (PDFA) approach for fast event detection on massive volumes of PMU data, taking advantage of a cluster computing platform. The PDFA algorithm is evaluated using data from installed PMUs on the transmission system of Great Britain from the aspects of speedup, scalability, and accuracy. The speedup of the PDFA in computation is initially analyzed through Amdahl's Law. A revision to the law is then proposed, suggesting enhancements to its capability to analyze the performance gain in computation when parallelizing data intensive applications in a cluster computing environment

    Paradoxical effects of Worrisome Thoughts Suppression: the influence of depressive mood

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    Thought suppression increases the persistence of unwanted idiosyncratic worries thoughts when individuals try to suppress them. The failure of suppression may contribute to the development and maintenance of emotional disorders. Depressive people seem particulary prone to engage in unsuccessful mental control strategies such as thought suppression. Worry has been reported to be elevated in depressed individuals and a dysphoric mood may also contribute for the failure of suppression. No studies examine, however, the suppression of worisome thoughts in individuals with depressive symptoms. To investigate the suppression effects of worrisome thoughts, 46 participants were selected according to the cut-off score of a depressive symptomatology scale and they were divided in two groups (subclinical and nonclinical group). All the individuals took part in an experimental paradigm of thought suppression. The results of the mixed factorial analysis of variance revealed an increased frequency of worrisome thoughts during the suppression phase on depending of the depressive symptoms. These findings confirm that depressive mood can reduce the success of suppression.info:eu-repo/semantics/publishedVersio

    Public health surveillance in the UK revolutionises our understanding of the invasive Salmonella Typhimurium epidemic in Africa

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    Background:The ST313 sequence type ofSalmonellaTyphimurium causes invasive non-typhoidal salmonellosis and wasthought to be confined to sub-Saharan Africa. Two distinct phylogenetic lineages of African ST313 have been identified.Methods:We analysed the whole genome sequences ofS. Typhimurium isolates from UK patients that weregenerated following the introduction of routine whole-genome sequencing (WGS) ofSalmonella entericabyPublic Health England in 2014.Results:We found that 2.7% (84/3147) ofS. Typhimurium from patients in England and Wales were ST313 and wereassociated with gastrointestinal infection. Phylogenetic analysis revealed novel diversity of ST313 that distinguishedUK-linked gastrointestinal isolates from African-associated extra-intestinal isolates. The majority of genome degradationof African ST313 lineage 2 was conserved in the UK-ST313, but the African lineages carried a characteristic prophageand antibiotic resistance gene repertoire. These findings suggest that a strong selection pressure exists for certainhorizontally acquired genetic elements in the African setting. One UK-isolated lineage 2 strain that probably originatedin Kenya carried a chromosomally locatedblaCTX-M-15, demonstrating the continual evolution of this sequence type inAfrica in response to widespread antibiotic usage.Conclusions:The discovery of ST313 isolates responsible for gastroenteritis in the UK reveals new diversity in thisimportant sequence type. This study highlights thepower of routine WGS by public health agencies to makeepidemiologically significant deductions that would be missed by conventional microbiological methods. Wespeculate that the niche specialisation of sub-Saharan African ST313 lineages is driven in part by the acquisitionof accessory genome elements

    Real-time selective sequencing using nanopore technology

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    The Oxford Nanopore Technologies MinION sequencer enables the selection of specific DNA molecules for sequencing by reversing the driving voltage across individual nanopores. To directly select molecules for sequencing, we used dynamic time warping to match reads to reference sequences. We demonstrate our open-source Read Until software in real-time selective sequencing of regions within small genomes, individual amplicon enrichment and normalization of an amplicon set

    Guilty by dissociation—development of gas chromatography–mass spectrometry (GC-MS) and other rapid screening methods for the analysis of 13 diphenidine-derived new psychoactive substances (NPSs)

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    © 2016, Springer-Verlag Berlin Heidelberg.The prevalence of new psychoactive substances (NPSs) in forensic casework has increased prominently in recent years. This has given rise to significant legal and analytical challenges in the identification of these substances. The requirement for validated, robust and rapid testing methodologies for these compounds is obvious. This study details the analysis of 13 synthesised diphenidine derivatives encountered in casework using presumptive testing, thin layer chromatography and gas chromatography–mass spectrometry (GC-MS). Specifically, the validated GC-MS method provides, for the first time, both a general screening method and quantification of the active components for seized solid samples, both in their pure form and in the presence of common adulterants. [Figure not available: see fulltext.

    Applying Benford’s law to detect accounting data manipulation in the banking industry

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    We utilise Benford’s Law to test if balance sheet and income statement data broadly used to assess bank soundness were manipulated prior to and also during the global financial crisis. We find that all banks resort to loan loss provisions to manipulate earnings and income upwards. Distressed institutions that have stronger incentives to conceal their financial difficulties resort additionally to manipulating loan loss allowances and non-performing loans downwards. Moreover, manipulation is magnified during the crisis and expands to encompass regulatory capital

    Phage typing or CRISPR typing for epidemiological surveillance of Salmonella Typhimurium?

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    Objective: Salmonella Typhimurium is the most dominant Salmonella serovar around the world. It is associated with foodborne gastroenteritis outbreaks but has recently been associated with invasive illness and deaths. Characterization of S. Typhimurium is therefore very crucial for epidemiological surveillance. Phage typing has been used for decades for subtyping of S. Typhimurium to determine the epidemiological relation among isolates. Recent studies however have suggested that high throughput clustered regular interspaced short palindromic repeats (CRISPR) typing has the potential to replace phage typing. This study aimed to determine the efficacy of highthroughput CRISPR typing over conventional phage typing in epidemiological surveillance and outbreak investigation of S. Typhimurium. Results: In silico analysis of whole genome sequences (WGS) of well-documented phage types of S. Typhimurium reveals the presence of different CRISPR type among strains belong to the same phage type. Furthermore, different phage types of S. Typhimurium share identical CRISPR type. Interestingly, identical spacers were detected among outbreak and non-outbreak associated DT8 strains of S. Typhimurium. Therefore, CRISPR typing is not useful for the epidemiological surveillance and outbreak investigation of S. Typhimurium and phage typing, until it is replaced by WGS, is still the gold standard method for epidemiological surveillance of S. Typhimurium
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